KINDAI UNIVERSITY


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KAWABATA Atsufumi

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FacultyDepartment of Pharmacy / Graduate School of Medicine / Pharmaceutical Research and Technology Institute
PositionProfessor
Degree
Commentator Guidehttps://www.kindai.ac.jp/meikan/564-kawabata-atsufumi.html
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Last Updated :2020/08/10

Education and Career

Education

  •  - 1985 , Kindai University
  •  - 1983 , Kindai University, Faculty of Pharmacy
  •  - 1985 , Kinki University, Graduate School, Division of Pharmaceutical Sciences
  •  - 1983 , Kinki University, Faculty of Pharmaceutical Science

Research Activities

Research Areas

  • Life sciences, Pharmacology
  • Life sciences, Pharmacology
  • Life sciences, Pharmacology
  • Life sciences, Pharmaceuticals - health and biochemistry

Research Interests

  • Radical, Protease, Receptor

Published Papers

  • Role of non-macrophage cell-derived HMGB1 in oxaliplatin-induced peripheral neuropathy and its prevention by the thrombin/thrombomodulin system in rodents: negative impact of anticoagulants., Tsubota M, Fukuda R, Hayashi Y, Miyazaki T, Ueda S, Yamashita R, Koike N, Sekiguchi F, Wake H, Wakatsuki S, Ujiie Y, Araki T, Nishibori M, Kawabata A, Journal of neuroinflammation, Journal of neuroinflammation, 16(1), 199, Oct. 2019 , Refereed
  • Genetic deletion of Cav3.2 T-type calcium channels abolishes H2S-dependent somatic and visceral pain signaling in C57BL/6 mice., Matsui K, Tsubota M, Fukushi S, Koike N, Masuda H, Kasanami Y, Miyazaki T, Sekiguchi F, Ohkubo T, Yoshida S, Mukai Y, Oita A, Takada M, Kawabata A, Journal of pharmacological sciences, Journal of pharmacological sciences, 140(3), 310 - 312, Jul. 2019 , Refereed
  • Dietary ascorbic acid restriction in GNL/SMP30-knockout mice unveils the role of ascorbic acid in regulation of somatic and visceral pain sensitivity., Tsubota M, Uebo K, Miki K, Sekiguchi F, Ishigami A, Kawabata A, Biochemical and biophysical research communications, Biochemical and biophysical research communications, 511(3), 705 - 710, Apr. 2019 , Refereed
  • NNC 55-0396, a T-type calcium channel blocker, protects against the brain injury induced by middle cerebral artery occlusion and reperfusion in mice., Matsuda S, Nishikawa H, Fukatsu A, Kurokawa Y, Tsubota M, Sekiguchi F, Tokuyama S, Kawabata A, Journal of pharmacological sciences, Journal of pharmacological sciences, 140(2), 193 - 196, Feb. 2019 , Refereed
  • [Regulation of Cav3.2-mediated pain signals by hydrogen sulfide]., Tsubota M, Kawabata A, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 154(3), 128 - 132, 2019 , Refereed
  • [Role of Cav3.2 T-type Ca2+ channels in prostate cancer cells]., Sekiguchi F, Kawabata A, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 154(3), 97 - 102, 2019 , Refereed
  • [HMGB1 as a target for prevention of chemotherapy-induced peripheral neuropathy]., Kawabata A, Tsubota M, Sekiguchi F, Tsujita R, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 154(5), 236 - 240, 2019 , Refereed
  • Critical role of Cav3.2 T-type calcium channels in the peripheral neuropathy induced by bortezomib, a proteasome-inhibiting chemotherapeutic agent, in mice., Tomita S, Sekiguchi F, Deguchi T, Miyazaki T, Ikeda Y, Tsubota M, Yoshida S, Nguyen HD, Okada T, Toyooka N, Kawabata A, Toxicology, Toxicology, 413, 33 - 39, Dec. 2018 , Refereed
  • The C-Reactive Protein/Albumin Ratio is Useful for Predicting Short-Term Survival in Cancer and Noncancer Patients., Miyamoto T, Fujitani M, Fukuyama H, Hatanaka S, Koizumi Y, Kawabata A, Journal of palliative medicine, Journal of palliative medicine, 22(5), 532 - 537, Dec. 2018 , Refereed
  • Paclitaxel-induced HMGB1 release from macrophages and its implication for peripheral neuropathy in mice: Evidence for a neuroimmune crosstalk., Sekiguchi F, Domoto R, Nakashima K, Yamasoba D, Yamanishi H, Tsubota M, Wake H, Nishibori M, Kawabata A, Neuropharmacology, Neuropharmacology, 141, 201 - 213, Sep. 2018 , Refereed
  • Blockade of T-type calcium channels by 6-prenylnaringenin, a hop component, alleviates neuropathic and visceral pain in mice., Sekiguchi F, Fujita T, Deguchi T, Yamaoka S, Tomochika K, Tsubota M, Ono S, Horaguchi Y, Ichii M, Ichikawa M, Ueno Y, Koike N, Tanino T, Nguyen HD, Okada T, Nishikawa H, Yoshida S, Ohkubo T, Toyooka N, Murata K, Matsuda H, Kawabata A, Neuropharmacology, Neuropharmacology, 138, 232 - 244, Aug. 2018 , Refereed
  • Design and synthesis of novel anti-hyperalgesic agents based on 6-prenylnaringenin as the T-type calcium channel blockers., Du Nguyen H, Okada T, Kitamura S, Yamaoka S, Horaguchi Y, Kasanami Y, Sekiguchi F, Tsubota M, Yoshida S, Nishikawa H, Kawabata A, Toyooka N, Bioorganic & medicinal chemistry, Bioorganic & medicinal chemistry, 26(15), 4410 - 4427, Aug. 2018 , Refereed
  • Involvement of the cystathionine-γ-lyase/Cav3.2 pathway in substance P-induced bladder pain in the mouse, a model for nonulcerative bladder pain syndrome., Tsubota M, Okawa Y, Irie Y, Maeda M, Ozaki T, Sekiguchi F, Ishikura H, Kawabata A, Neuropharmacology, Neuropharmacology, 133, 254 - 263, May 2018 , Refereed
  • Involvement of NF-κB in the upregulation of cystathionine-γ-lyase, a hydrogen sulfide-forming enzyme, and bladder pain accompanying cystitis in mice., Ozaki T, Tsubota M, Sekiguchi F, Kawabata A, Clinical and experimental pharmacology & physiology, Clinical and experimental pharmacology & physiology, 45(4), 355 - 361, Apr. 2018 , Refereed
  • Involvement of Voltage-Gated Calcium Channels in Inflammation and Inflammatory Pain., Sekiguchi F, Tsubota M, Kawabata A, Biological & pharmaceutical bulletin, Biological & pharmaceutical bulletin, 41(8), 1127 - 1134, 2018 , Refereed
  • Zinc deficiency promotes cystitis-related bladder pain by enhancing function and expression of Cav3.2 in mice., Ozaki T, Matsuoka J, Tsubota M, Tomita S, Sekiguchi F, Minami T, Kawabata A, Toxicology, Toxicology, 393, 102 - 112, Jan. 2018 , Refereed
  • Human soluble thrombomodulin-induced blockade of peripheral HMGB1-dependent allodynia in mice requires both the lectin-like and EGF-like domains., Hayashi Y, Tsujita R, Tsubota M, Saeki H, Sekiguchi F, Honda G, Kawabata A, Biochemical and biophysical research communications, Biochemical and biophysical research communications, 495(1), 634 - 638, Jan. 2018 , Refereed
  • Prostanoid-dependent bladder pain caused by proteinase-activated receptor-2 activation in mice: Involvement of TRPV1 and T-type Ca2+ channels., Tsubota M, Ozaki T, Hayashi Y, Okawa Y, Fujimura A, Sekiguchi F, Nishikawa H, Kawabata A, Journal of pharmacological sciences, Journal of pharmacological sciences, 136(1), 46 - 49, Jan. 2018 , Refereed
  • Role of Thrombin in Soluble Thrombomodulin-Induced Suppression of Peripheral HMGB1-Mediated Allodynia in Mice., Tsujita R, Tsubota M, Hayashi Y, Saeki H, Sekiguchi F, Kawabata A, Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, 13(2), 179 - 188, Dec. 2017 , Refereed
  • H2S and Pain: A Novel Aspect for Processing of Somatic, Visceral and Neuropathic Pain Signals., Terada Y, Kawabata A, Handbook of experimental pharmacology, Handbook of experimental pharmacology, 230, 217 - 230, 2015 , Refereed
  • Recombinant human soluble thrombomodulin prevents peripheral HMGB1-dependent hyperalgesia in rats., Tanaka J, Seki Y, Ishikura H, Tsubota M, Sekiguchi F, Yamaguchi K, Murai A, Umemura T, Kawabata A, British journal of pharmacology, British journal of pharmacology, 170(6), 1233 - 1241, Nov. 2013 , Refereed
  • [Targeting Ca(v)3.2 T-type calcium channels as a therapeutic strategy for chemotherapy-induced neuropathic pain]., Kawabata A, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 141(2), 81 - 84, Feb. 2013 , Refereed
  • Antihyperalgesic effect of buprenorphine involves nociceptin/orphanin FQ peptide-receptor activation in rats with spinal nerve injury-induced neuropathy., Takahashi T, Okubo K, Kojima S, Nishikawa H, Takemura M, Tsubota-Matsunami M, Sekiguchi F, Kawabata A, Journal of pharmacological sciences, Journal of pharmacological sciences, 122(1), 51 - 54, 2013 , Refereed
  • Lipid mediators and pain signaling. Foreword., Kawabata A, Biological & pharmaceutical bulletin, Biological & pharmaceutical bulletin, 34(8), 1153, 2011 , Refereed
  • Curcumin Inhibits the Proteinase-Activated Receptor-2-Triggered Prostaglandin E-2 Production by Suppressing Cyclooxygenase-2 Upregulation and Akt-Dependent Activation of Nuclear Factor-kappa B in Human Lung Epithelial Cells, Kazumi Moriyuki, Fumiko Sekiguchi, Kaori Matsubara, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 114(2), 225 - 229, Oct. 2010 , Refereed
    Summary:We performed this study to determine if curcumin affects pro-inflammatory responses to activation of proteinase-activated receptor-2 (PAR2) in human pulmonary adenocarcinoma A549 cells. Curcumin completely inhibited the PAR2-triggered prostaglandin E-2 (PGE(2)) production, but notably not interleukin-8 release. Cyclooxygenase-2 (COX-2) upregulation, but not its upstream activation of mitogen-activated protein kinases, caused by PAR2 stimulation was partially inhibited by curcumin. Curcumin inhibited the PAR2-triggered phosphorylation of I-kappa B, an indicator for nuclear factor-kappa B (NF-kappa B) activation, and also its upstream signal Akt, which is known to contribute to PAR2-triggered PGE2 formation, but not COX-2 upregulation. Collectively, curcumin inhibits the PAR2-triggered PGE2 production by suppressing COX-2 upregulation and Akt/NF-kappa B signals in A549 cells.
  • Proteinase-Activated Receptor-2-Triggered Prostaglandin E-2 Release, but Not Cyclooxygenase-2 Upregulation, Requires Activation of the Phosphatidylinositol 3-Kinase/Akt/Nuclear Factor-kappa B Pathway in Human Alveolar Epithelial Cells, Kazumi Moriyuki, Fumiko Sekiguchi, Kaori Matsubara, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 111(3), 269 - 275, Nov. 2009
    Summary:Proteinase-activated receptor-2 (PAR2) triggers upregulation of cyclooxygenase-2 (COX-2) and prostaglandin E-2 (PGE(2)) formation in human alveolar epithelial A549 cells. This COX-2 upregulation appears to involve the Src/epidermal growth factor (EGF) receptor/p38 MAP kinase (p38MAPK) pathway and also the cAMP-response element-binding protein (CREB) pathway. Here, we investigated the roles of nuclear factor-kappa B (NF-kappa B)-related signals in the PAR2-triggered PGE(2) release/COX-2 upregulation in A549 cells. The PAR2-triggered PGE2 release was clearly blocked by an inhibitor of the NF-kappa B pathway. Stimulation of PAR2 actually caused phosphorylation of inhibitor-kappa B, an indicator of NF-kappa B activation, an effect being blocked by inhibitors of MEK, phosphatidylinositol 3-kinase (PI3-kinase), and Akt, but little or not by inhibitors of p38MAPK and JNK. Stimulation of PAR2 also caused phosphorylation of Akt, an effect suppressed by inhibitors of PI3-kinase and MEK. Nonetheless, the PAR2-triggered upregulation of COX-2 was resistant to inhibitors of NF-kappa B, PI3-kinase, and Akt, but was attenuated by inhibitors of MEK and JNK. Stimulation of PAR2 induced phosphorylation of CREB, an effect abolished by an inhibitor of MEK but not inhibitors of p38MAPK and EGF receptor. These findings demonstrate that the MEK / ERK / PI3-kinase / Akt / NF-kappa B pathway is involved in PAR2-triggered PGE2 formation, but not upregulation of COX-2 that is dependent on activation of ERK/CREB and JNK in addition to p38MAPK.
  • Rhodanese, but not cystathionine-gamma-lyase, is associated with dextran sulfate sodium-evoked colitis in mice: A sign of impaired colonic sulfide detoxification?, Eiichi Taniguchi, Maho Matsunami, Takeshi Kimura, Daiki Yonezawa, Tsuyoshi Ishiki, Fumiko Sekiguchi, Hiroyuki Nishikawa, Yuma Maeda, Hiroyasu Ishikura, Atsufumi Kawabata, TOXICOLOGY, TOXICOLOGY, 264(1-2), 96 - 103, Oct. 2009
    Summary:Clinical studies suggest that colonic luminal hydrogen sulfide (H(2)S), produced by sulfate-reducing bacteria or through other pathways, might be involved in the pathogenesis of inflammatory bowel disease (IBD). Nonetheless, this hypothesis has been poorly investigated by basic studies using laboratory animals. We thus focused on two enzymes, cystathionine-gamma-lyase (CSE) that generates H(2)S from L-cysteine, and rhodanese that directly or indirectly detoxifies H(2)S, particularly in relation to the colitis induced by dextran sulfate sodium (DSS) in mice. CSE was a major H(2)S-forming enzyme in colonic and renal homogenates from mice and rats, and the rhodanese activity was also detectable in both tissues. Colitis-related symptoms including decreased body weight gain, diarrhea, hematochezia and shortening of colon length were observed in the mice drinking DSS. Those symptoms were not or only slightly attenuated by repeated administration of a CSE inhibitor. CSE activity and protein levels in the colonic tissue did not notably change in the mice with colitis. In contrast, the activity and protein/mRNA levels of rhodanese in the colon, but not kidney, significantly decreased nearly in parallel with the development of colitis, followed by elevation of rhodanese activity in red blood cells (RBCs). These data show that rhodanese, but not CSE, is associated with DSS-induced colitis in mice, leading to a hypothesis that impaired detoxification of H(2)S due to down-regulation or suppression of colonic rhodanese is involved in IBD. The delayed enhancement of rhodanese activity in RBCs, a possible compensative event, might be available as a disease marker for IBD. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Dual modulation of the tension of isolated gastric artery and gastric mucosal circulation by hydrogen sulfide in rats., Inflammopharmacology, Inflammopharmacology, 15(6), 288 - 292, Dec. 2007
  • Proteinase-activated receptors in the gastrointestinal system: a functional linkage to prostanoids., Inflammopharmacology, Inflammopharmacology, 15(6), 246 - 251, Dec. 2007
  • Distinct activity of peptide mimetic intracellular ligands (pepducins) for proteinase-activated receptor-1 in multiple cells/tissues, Kubo S, Ishiki T, Doe I, Sekiguchi F, Nishikawa H, Kawai K, Matsui H, Kawabata A, Ann N Y Acad Sci, Ann N Y Acad Sci, 1091, 115 - 459, Dec. 2006 , Refereed
  • [Proteinase-activated receptors and gastrointestinal functions]., Kawabata A, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 128(2), 82 - 87, Aug. 2006 , Refereed
  • [Proteinase-activated receptor-2 and pain]., Kawabata A, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 127(3), 133 - 6, 146, Mar. 2006 , Refereed
  • [PAR (protease-activated receptor) as a novel target for development of gastric mucosal cytoprotective drugs]., Kawabata A, Kuroda R, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 120(1), 85P - 87P, Nov. 2002 , Refereed
  • Macrophage-derived HMGB1 as a Pain Mediator in the Early Stage of Acute Pancreatitis in Mice: Targeting RAGE and CXCL12/CXCR4 Axis, Yuhei Irie, Maho Tsubota, Hiroyasu Ishikura, Fumiko Sekiguchi, Yuka Terada, Toshifumi Tsujiuchi, Keyue Liu, Masahiro Nishibori, Atsufumi Kawabata, JOURNAL OF NEUROIMMUNE PHARMACOLOGY, JOURNAL OF NEUROIMMUNE PHARMACOLOGY, 12(4), 693 - 707, Dec. 2017 , Refereed
    Summary:Extracellular high mobility group box 1 (HMGB1) activates the receptor for advanced glycation end products (RAGE) or Toll-like receptor 4 (TLR4) and forms a heterocomplex with CXCL12 that strongly activates CXCR4, promoting inflammatory and pain signals. In the present study, we investigated the role of HMGB1 in pancreatic pain accompanying cerulein-induced acute pancreatitis in mice. Abdominal referred hyperalgesia accompanying acute pancreatitis occurred within 1 h after 6 hourly injections of cerulein. The anti-HMGB1 neutralizing antibody or recombinant human soluble thrombomodulin (rhsTM), known to inactivate HMGB1, abolished the cerulein-induced referred hyperalgesia, but not pancreatitis itself. Plasma or pancreatic HMGB1 levels did not change, but macrophage infiltration into the pancreas occurred 1 h after cerulein treatment. Minocycline, a macrophage/microglia inhibitor, ethyl pyruvate that inhibits HMGB1 release from macrophages, or liposomal clodronate that depletes macrophages prevented the referred hyperalgesia, but not pancreatitis. Antagonists of RAGE or CXCR4, but not TLR4, strongly suppressed the cerulein-induced referred hyperalgesia, but not pancreatitis. Upregulation of RAGE, CXCR4 and CXCL12, but not TLR4, were detected in the pancreas 1 h after cerulein treatment. Our data suggest that HMGB1 regionally secreted by macrophages mediates pancreatic pain by targeting RAGE and CXCL12/CXCR4 axis in the early stage of acute pancreatitis.
  • Circadian pharmacokinetics and limited sampling strategy of everolimus in heart transplant patients, Yuka Terada, Kyoichi Wada, Sachi Matsuda, Takeshi Kuwahara, Atsufumi Kawabata, Mitsutaka Takada, Takuya Watanabe, Seiko Nakajima, Takuma Sato, Osamu Seguchi, Masanobu Yanase, Norihide Fukushima, Takeshi Nakatani, INTERNATIONAL JOURNAL OF CLINICAL PHARMACOLOGY AND THERAPEUTICS, INTERNATIONAL JOURNAL OF CLINICAL PHARMACOLOGY AND THERAPEUTICS, 55(1), 1 - 8, Jan. 2017 , Refereed
    Summary:Objective: To evaluate circadian changes in everolimus (EVL) pharmacokinetics and to identify the time point of blood sampling with the strongest correlation with the area under the blood concentration time curve (AUC) of EVL in heart transplant patients. Methods: Heart transplant patients receiving the same dose of EVL twice a day were reviewed. In 28 patients enrolled, whole blood samples were collected before (C-0), and 1, 2, 4, 6, 8, and 12 hours after each administration of EVL. Blood concentrations of EVL were compared between active (9:00 AM to 9:00 PM) and resting periods (9:00 PM to 9:00 AM). Results: AUC(0-4h), peak concentration (C-max), C-max/minimum concentration, and peak-trough fluctuation in the resting period were significantly lower than those in the active period (p = 0.008, 0.017, 0.022, and 0.011, respectively). Halflife and mean residence time were significantly longer in the resting period than in the active period (p = 0.002 and 0.002, respectively). AUC(0-12h) in the active period was similar (p = 0.154) and correlated with that in the resting period (r(2) = 0.93). Two-point blood samplings, C-0 and C-2, correlated more strongly with AUC(0-12h) for EVL, compared with C-0 alone (0.92 vs. 0.79, respectively, for r(2) in the active period). Conclusions: EVL pharmacokinetics showed circadian changes, suggesting delayed absorption and decreased metabolic activity at rest. However, the circadian changes did not affect AUC(0-12h). A 2-time-point model that included C-0 and C-2 was more accurate for predicting the AUC(0-12h) of EVL than C-0 alone in heart transplant patients.
  • Hydrogen Sulfide and T-Type Ca2+ Channels in Pain Processing, Neuronal Differentiation and Neuroendocrine Secretion, Kazuki Fukami, Fumiko Sekiguchi, Atsufumi Kawabata, PHARMACOLOGY, PHARMACOLOGY, 99(3-4), 196 - 203, 2017 , Refereed
    Summary:Background: Hydrogen sulfide (H2S), a gasotransmitter, is generated from L-cysteine by mainly 3 enzymes, cystathionine-Upsilon-lyase (CSE), cystathionine-beta-synthase, and 3-mercaptopyruvate sulfurtransferase in cooperation with cysteine aminotransferase. The H2S-forming enzymes, particularly CSE, are overexpressed under the pathological conditions such as inflammation, neuronal or neuroendocrine differentiation and cancer development. Given that Ca(v)3.2 T-type Ca2+ channels mediate some of the biological activity of H2S, we focus on the role of the H2S/Ca(v)3.2 pathway in regulating the neuronal and neuroendocrine function. Summary: In the neuronal system, H2S regulates the activity of various ion channels including Ca(v)3.2. Exogenous and endogenous H2S enhances the Ca(v)3.2 channel activity, promoting somatic and visceral pain signaling. The H2S/Ca(v)3.2 pathway also facilitates neuritogenesis or neuronal differentiation. Interestingly, endogenous H2S formed by CSE regulates secretory function by enhancing Ca(v)3.2 channel activity in neuroendocrine-differentiated prostate cancer cells or carotid glomus cells. Key Messages: The H2S/Ca(v)3.2 pathway may serve as therapeutic targets for treatment of intractable pain, neuronal injury, androgen-independent prostate cancer, cardiovascular diseases, etc. (C) 2016 S. Karger AG, Basel
  • Enhanced Hyperthermic Responses to Lipopolysaccharide in Mice Exposed to Repeated Cold Stress, Tomoyoshi Miyamoto, Yoshinori Funakami, Erika Kawashita, Shiori Tomita, Ai Nomura, Nanako Sugimoto, Haruka Saeki, Takaya Miyazaki, Maho Tsubota, Seiji Ichida, Atsufumi Kawabata, PHARMACOLOGY, PHARMACOLOGY, 99(3-4), 172 - 178, 2017 , Refereed
    Summary:Lipopolysaccharide (LPS) induces hyperthermia accompanied by various other systemic inflammatory symptoms. The rodents exposed to repeated cold (RC) stress according to a specific schedule are useful as experimental models for autonomic imbalance or fibromyalgia. It is now proven that RC-stressed mice exhibit tolerance to LPS, we examined thermal responses to LPS challenge in RC-stressed mice by monitoring core temperature using the telemetry system. Systemic administration of LPS caused bimodal hyperthermic responses in RC-stressed and unstressed mice. The magnitude of the LPS-induced hyperthermia was greater in RC-stressed mice than in unstressed mice. The RC stress-induced enhancement of hyperthermic responses to LPS was abolished by pretreatment with diclofenac, which is a cyclooxygenase (COX) inhibitor. LPS did not significantly increase COX-2 protein levels in the lung or hypothalamus of RC-stressed or unstressed mice. RC stress did not alter baseline serum corticosterone levels or their increases in response to LPS challenge. These results suggest that RC stress enhances the susceptibility of mice to LPS challenge, leading to greater prostanoid-dependent hyperthermia, which might contribute to tolerance to LPS in RC-stressed mice. (C) 2016 S. Karger AG, Basel.
  • Repeated Cold Stress Enhances the Acute Restraint Stress-Induced Hyperthermia in Mice, Tomoyoshi Miyamoto, Yoshinori Funakami, Erika Kawashita, Ai Nomura, Nanako Sugimoto, Haruka Saeki, Maho Tsubota, Seiji Ichida, Atsufumi Kawabata, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 40(1), 11 - 16, Jan. 2017 , Refereed
    Summary:The rodents exposed to repeated cold stress according to a specific schedule, known as specific alternation of rhythm in temperature (SART), exhibit autonomic imbalance, and is now used as an experimental model of fibromyalgia. To explore the susceptibility of SART-stressed animals to novel acute stress, we tested whether exposure of mice to SART stress for 1 week alters the extent of acute restraint stress-induced hyperthermia. Mice were subjected to 7-d SART stress sessions; i.e., the mice were alternately exposed to 24 and 4 degrees C at 1-h intervals during the daytime (09:00-16:00) and kept at 4 degrees C overnight (16:00-09:00). SART-stressed and unstressed mice were exposed to acute restraint stress for 20-60 min, during which rectal temperature was monitored. Serum corticosterone levels were measured before and after 60-min exposure to restraint stress. SART stress itself did not alter the body temperature or serum corticosterone levels in mice. Acute restraint stress increased the body temperature and serum corticosterone levels, both responses being greater in SART-stressed mice than unstressed mice. The enhanced hyperthermic responses to acute restraint stress in SART-stressed mice were significantly attenuated by SR59230A, a beta(3) adrenoceptor antagonist, but unaffected by diazepam, an anxiolytic, mifepristone, a glucocorticoid receptor antagonist, or indomethacin, a cyclooxygenase inhibitor. These results suggest that SART stress enhances the susceptibility of mice to acute restraint stress, characterized by increased hyperthermia and corticosterone secretion, and that the increased hyperthermic responses to acute stress might involve accelerated activation of sympathetic beta(3) adrenoceptors, known to regulate non-shivering thermogenesis in the brown adipose tissue.
  • High glucose induces N-linked glycosylation-mediated functional upregulation and overexpression of Ca(v)3.2 T-type calcium channels in neuroendocrine-like differentiated human prostate cancer cells, Kazuki Fukami, Erina Asano, Mai Ueda, Fumiko Sekiguchi, Shigeru Yoshida, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 133(1), 57 - 60, Jan. 2017 , Refereed
    Summary:Given that Ca(v)3.2 T-type Ca2+ channels were functionally regulated by asparagine (N)-linked glycosylation, we examined effects of high glucose on the function of Ca(v)3.2, known to regulate secretory function, in neuroendocrine-like differentiated prostate cancer LNCaP cells. High glucose accelerated the increased channel function and overexpression of Ca(v)3.2 during neuroendocrine differentiation, the former prevented by enzymatic inhibition of N-glycosylation and cleavage of N-glycans. Hyperglycemia thus appears to induce N-linked glycosylation-mediated functional upregulation and overexpression of Ca(v)3.2 in neuroendocrine-like differentiated prostate cancer cells. (C) 2017 The Authors. Production and hosting by Elsevier B.V. on behalf of Japanese Pharmacological Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
  • Tacrolimus Triggers Transient Receptor Potential Vanilloid-1-Dependent Relapse of Pancreatitis-Related Pain in Mice, Yuka Terada, Maho Tsubota, Hiiragi Sugo, Kohei Wakitani, Fumiko Sekiguchi, Kyoichi Wada, Mitsutaka Takada, Akira Oita, Atsufumi Kawabata, PHARMACOLOGY, PHARMACOLOGY, 99(5-6), 281 - 285, 2017 , Refereed
    Summary:Transient receptor potential vanilloid-1 (TRPV1) expressed in nociceptors is directly phosphorylated and activated by protein kinase C, and involved in the signaling of pancreatic pain. On the other hand, Ca(v)3.2 T-type Ca2+ channels expressed in nociceptors are functionally upregulated by phosphorylation with protein kinase A and also play a role in pancreatitis-related pain. Calcineurin, a phosphatase, negatively regulates various channel functions including TRPV1, and calcineurin inhibitor-induced pain syndrome by tacrolimus, a calcineurin inhibitor, used as an immunosuppressant, has been a clinical problem. We thus examined the effect of tacrolimus on pancreatitis-related pain in mice. Repeated treatment with cerulein caused referred hyperalgesia accompanying acute pancreatitis, which was unaffected by tacrolimus. Pancreatitis-related symptoms disappeared in 24 h, whereas the referred hyperalgesia recurred following the administration of tacrolimus, which was abolished by the blockers of TRPV1 but not T-type Ca2+ channels. Thus, tacrolimus appears to cause the TRPV1-dependent relapse of pancreatitis-related pain, suggesting the involvement of calcineurin in the termination of pancreatic pain. (C) 2017 S. Karger AG, Basel
  • Repeated Cold Stress Reduces Cyclophosphamide-Induced Cystitis/Bladder Pain and Macrophage Activity in Mice, Maho Tsubota, Tomoyoshi Miyamoto, Saki Hiruma, Haruka Saeki, Takaya Miyazaki, Fumiko Sekiguchi, Yoshinori Funakami, Atsufumi Kawabata, PHARMACOLOGY, PHARMACOLOGY, 99(5-6), 286 - 290, 2017 , Refereed
    Summary:We examined the effect of repeated cold (RC) stress on cyclophosphamide (CPA)-induced cystitis/bladder pain in mice, in relation to macrophage activity. CPA, given i.p. at 400 mg/kg, caused bladder pain symptoms accompanying cystitis in both unstressed and RC-stressed mice, which were prevented by the macrophage inhibitor minocycline. A low dose, that is, 200 mg/kg, of CPA still produced bladder pain symptoms in unstressed but not RC-stressed mice. Lipopoly-saccharide-induced cytokine production in peritoneal macrophages from RC-stressed mice was less than that from unstressed mice. Thus, RC stress appears to reduce CPA-induced bladder pain in mice, which may be associated with the decreased macrophage activity. (C) 2017 S. Karger AG, Basel
  • Therapeutic potential of RQ-00311651, a novel T-type Ca2+ channel blocker, in distinct rodent models for neuropathic and visceral pain, Fumiko Sekiguchi, Yuma Kawara, Maho Tsubota, Eri Kawakami, Tomoka Ozaki, Yudai Kawaishi, Shiori Tomita, Daiki Kanaoka, Shigeru Yoshida, Tsuyako Ohkubo, Atsufumi Kawabata, PAIN, PAIN, 157(8), 1655 - 1665, Aug. 2016 , Refereed
    Summary:T-type Ca2+ channels (T channels), particularly Ca(v)3.2 among the 3 isoforms, play a role in neuropathic and visceral pain. We thus characterized the effects of RQ-00311651 (RQ), a novel T-channel blocker, in HEK293 cells transfected with human Ca(v)3.1 or Ca(v)3.2 by electrophysiological and fluorescent Ca2+ signaling assays, and also evaluated the antiallodynic/antihyperalgesic activity of RQ in somatic, visceral, and neuropathic pain models in rodents. RQ-00311651 strongly suppressed T currents when tested at holding potentials of -65 similar to - 260 mV, but not -80 mV, in the Ca(v)3.1- or Ca(v)3.2-expressing cells. RQ-00311651 also inhibited high K+-induced Ca2+ signaling in those cells. In mice, RQ, administered intraperitoneally (i.p.) at 5 to 20 mg/kg or orally at 20 to 40 mg/kg, significantly suppressed the somatic hyperalgesia and visceral pain-like nociceptive behavior/referred hyperalgesia caused by intraplantar and intracolonic administration of NaHS or Na2S, H2S donors, respectively, which involve the enhanced activity of Ca(v)3.2 channels. RQ-00311651, given i.p. at 5 to 20 mg/kg, exhibited antiallodynic or antihyperalgesic activity in rats with spinal nerve injury-induced neuropathy or in rats and mice with paclitaxel-induced neuropathy. Oral and i.p. RQ at 10 to 20 mg/kg also suppressed the visceral nociceptive behavior and/or referred hyperalgesia accompanying cerulein-induced acute pancreatitis and cyclophosphamide-induced cystitis in mice. The analgesic and antihyperalgesic/antiallodynic doses of oral and i.p. RQ did not significantly affect the locomotor activity and motor coordination. Together, RQ is considered a state-dependent blocker of Ca(v)3.1/Ca(v)3.2 T channels and may serve as an orally available analgesic for treatment of neuropathic and inflammatory pain including distinct visceral pain with minimum central side effects.
  • Involvement of high mobility group box 1 in the development and maintenance of chemotherapy-induced peripheral neuropathy in rats, Takeshi Nishida, Maho Tsubota, Yudai Kawaishi, Hiroki Yamanishi, Natsuki Kamitani, Fumiko Sekiguchi, Hiroyasu Ishikura, Keyue Liu, Masahiro Nishibori, Atsufumi Kawabata, TOXICOLOGY, TOXICOLOGY, 365, 48 - 58, Jul. 2016 , Refereed
    Summary:Given that high mobility group box 1 (HMGB1), a nuclear protein, once released to the extracellular space, promotes nociception, we asked if inactivation of HMGB1 prevents or reverses chemotherapy-induced painful neuropathy in rats and also examined possible involvement of Toll-like receptor 4 (TLR4) and the receptor for advanced glycation endproduct (RAGE), known as targets for HMGB1. Painful neuropathy was produced by repeated i.p. administration of paclitaxel or vincristine in rats. Nociceptive threshold was determined by the paw pressure method and/or von Frey test in the hindpaw. Tissue protein levels were determined by immunoblotting. Repeated i.p. administration of the anti-HMGB1-neutralizing antibody or recombinant human soluble thrombomodulin (rhsTM), known to inactivate HMGB1, prevented the development of hyperalgesia and/or allodynia induced by paclitaxel or vincristine in rats. A single i.p. or intraplantar (i.pl.) administration of the antibody or rhsTM reversed the chemotherapy induced neuropathy. A single i.pl. administration of a TLR4 antagonist or low molecular weight heparin, known to inhibit RAGE, attenuated the hyperalgesia caused by i.pl. HMGB1 and also the chemotherapy induced painful neuropathy. Paclitaxel or vincristine treatment significantly decreased protein levels of HMGB1 in the dorsal root ganglia, but not sciatic nerves. HMGB1 thus participates in both development and maintenance of chemotherapy-induced painful neuropathy, in part through RAGE and TLR4. HMGB1 inactivation is considered useful to prevent and treat the chemotherapy-induced painful neuropathy. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
  • Endogenous Hydrogen Sulfide Enhances Cell Proliferation of Human Gastric Cancer AGS Cells, Fumiko Sekiguchi, Teruki Sekimoto, Ayaka Ogura, Atsufumi Kawabata, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 39(5), 887 - 890, May 2016 , Refereed
    Summary:Hydrogen sulfide (H2S), the third gasotransmitter, is endogenously generated by certain H2S synthesizing enzymes, including cystathionine-gamma-lyase (CSE) and cystathionine-beta-synthase (CBS) from L-cysteine in the mammalian body. Several studies have shown that endogenous and exogenous H2S affects the proliferation of cancer cells, although the effects of H2S appear to vary with cell type, being either promotive or suppressive. In the present study, we determined whether endogenously formed H2S regulates proliferation in human gastric cancer AGS cells. CSE, but not CBS, was expressed in AGS cells. CSE inhibitors, DL-propargylglycine (PPG) and beta-cyano-L-alanine (BCA), significantly suppressed the proliferation of AGS cells in a concentration-dependent manner. CSE inhibitors did not increase lactate dehydrogenase (LDH) release in the same concentration range. The inhibitory effects of PPG and BCA on cell proliferation were reversed by repetitive application of NaHS, a donor of H2S. Interestingly, nuclear condensation and fragmentation were detected in AGS cells treated with PPG or BCA. These results suggest that endogenous H2S produced by CSE may contribute to the proliferation of gastric cancer AGS cells, most probably through anti-apoptotic actions.
  • The prostaglandin E-2/EP4 receptor/cyclic AMP/T-type Ca2+ channel pathway mediates neuritogenesis in sensory neuron-like ND7/23 cells, Kenji Mitani, Fumiko Sekiguchi, Takashi Maeda, Yukari Tanaka, Shigeru Yoshida, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 130(3), 177 - 180, Mar. 2016 , Refereed
    Summary:We investigated mechanisms for the neuritogenesis caused by prostaglandin E-2 (PGE(2)) or intracellular cyclic AMP (cAMP) in sensory neuron-like ND7/23 cells. PGE(2) caused neuritogenesis, an effect abolished by an EP4 receptor antagonist or inhibitors of adenylyl cyclase (AC) or protein kinase A (PKA) and mimicked by the AC activator forskolin, dibutyryl cAMP (db-cAMP), and selective activators of PKA or Epac. ND7/23 cells expressed both Ca(v)3.1 and Ca(v)3.2 T-type Ca2+ channels (T-channels). The neuritogenesis induced by db-cAMP or PGE(2) was abolished by T-channel blockers. T-channels were functionally upregulated by db-cAMP. The PGE(2)/EP4/cAMP/T-channel pathway thus appears to mediate neuritogenesis in sensory neurons. (C) 2016 Japanese Pharmacological Society. Production and hosting by Elsevier B.V.
  • Peripheral HMGB1-induced hyperalgesia in mice: Redox state-dependent distinct roles of RAGE and TLR4, Daichi Yamasoba, Maho Tsubota, Risa Domoto, Fumiko Sekiguchi, Hiroyuki Nishikawa, Keyue Liu, Masahiro Nishibori, Hiroyasu Ishikura, Tetsushi Yamamoto, Atsushi Taga, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 130(2), 139 - 142, Feb. 2016 , Refereed
    Summary:Nuclear HMGB1 that contains 3 cysteine residues is acetylated and secreted to the extracellular space, promoting inflammation via multiple molecules such as RAGE and TLR4. We thus evaluated and characterized the redox state-dependent effects of peripheral HMGB1 on nociception. Intraplantar (i.pl.) administration of bovine thymus-derived HMGB1 (bt-HMGB1), all-thiol HMGB1 (at-HMGB1) or disulfide HMGB1 (ds-HMGB1) caused long-lasting mechanical hyperalgesia in mice. The hyperalgesia following i.pl. bt-HMGB1 or at-HMGB1 was attenuated by RAGE inhibitors, while the ds-HMGB1-induced hyperalgesia was abolished by a TLR4 antagonist. Thus, nociceptive processing by peripheral HMGB1 is considered dependent on its redox states. (C) 2016 Japanese Pharmacological Society. Production and hosting by Elsevier B.V.
  • Selective sensitization of C-fiber nociceptors by hydrogen sulfide, Yuka Aoki, Maho Tsubota, Yuta Nishimoto, Yumi Maeda, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 130(1), 38 - 41, Jan. 2016 , Refereed
    Summary:We examined the effects of intraplantar (i.pl.) administration of NaHS, an H2S donor, known to cause T-type Ca2+ channel (T-channel)-dependent mechanical hyperalgesia, on responsiveness to electric stimulation with 5, 250 and 2000 Hz sine waves (SW) that selectively excites C, A delta and A beta fibers, respectively. NaHS, given i.pl., caused behavioral hypersensitivity to SW stimulation at 5 Hz, but not 250 or 2000 Hz, in rats. NaHS also enhanced phosphorylation of spinal ERK following 5 Hz SW stimulation. Three distinct T-channel blockers abolished the NaHS-induced behavioral hypersensitivity to 5 Hz SW stimulation. Thus, H2S selectively sensitizes C-fiber nociceptors via T-channels. (C) 2016 Japanese Pharmacological Society. Production and hosting by Elsevier B.V.
  • Intravenous Administration of Cilostazol Nanoparticles Ameliorates Acute Ischemic Stroke in a Cerebral Ischemia/Reperfusion-Induced Injury Model, Noriaki Nagai, Chiaki Yoshioka, Yoshimasa Ito, Yoshinori Funakami, Hiroyuki Nishikawa, Atsufumi Kawabata, INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, 16(12), 29329 - 29344, Dec. 2015 , Refereed
    Summary:It was reported that cilostazol (CLZ) suppressed disruption of the microvasculature in ischemic areas. In this study, we have designed novel injection formulations containing CLZ nanoparticles using 0.5% methylcellulose, 0.2% docusate sodium salt, and mill methods (CLZ(nano) dispersion; particle size 81 +/- 59 nm, mean +/- S.D.), and investigated their toxicity and usefulness in a cerebral ischemia/reperfusion-induced injury model (MCAO/reperfusion mice). The pharmacokinetics of injections of CLZ(nano) dispersions is similar to that of CLZ solutions prepared with 2-hydroxypropyl--cyclodextrin, and no changes in the rate of hemolysis of rabbit red blood cells, a model of cell injury, were observed with CLZ(nano) dispersions. In addition, the intravenous injection of 0.6 mg/kg CLZ(nano) dispersions does not affect the blood pressure and blood flow, and the 0.6 mg/kg CLZ(nano) dispersions ameliorate neurological deficits and ischemic stroke in MCAO/reperfusion mice. It is possible that the CLZ(nano) dispersions will provide effective therapy for ischemic stroke patients, and that injection preparations of lipophilic drugs containing drug nanoparticles expand their therapeutic usage.
  • Functional upregulation of the H2S/Ca(v)3.2 channel pathway accelerates secretory function in neuroendocrine-differentiated human prostate cancer cells, Kazuki Fukami, Fumiko Sekiguchi, Miku Yasukawa, Erina Asano, Ryuji Kasamatsu, Mai Ueda, Shigeru Yoshida, Atsufumi Kawabata, BIOCHEMICAL PHARMACOLOGY, BIOCHEMICAL PHARMACOLOGY, 97(3), 300 - 309, Oct. 2015 , Refereed
    Summary:Neuroendocrine-differentiated prostate cancer cells may contribute to androgen-independent proliferation of surrounding cells through Ca2+-dependent secretion of mitogenic factors. Human prostate cancer LNCaP cells, when neuroendocrine-differentiated, overexpress Ca(v)3.2 T-type Ca2+ channels that contribute to Ca2+-dependent secretion. Given evidence for the acceleration of Ca(v)3.2 activity by hydrogen sulfide (H2S), we examined the roles of the H2S/Ca(v)3.2 pathway and then analyzed the molecular mechanisms of the Ca(v)3.2 overexpression in neuroendocrine-differentiated LNCaP cells. LNCaP cells were differentiated by dibutyryl cyclic AMP. Protein levels and T-type Ca2+ channeldependent currents (T-currents) were measured by immunoblotting and whole-cell pacth-clamp technique, respectively. Spontaneous release of prostatic acid phosphatase (PAP) was monitored to evaluate secretory function. The differentiated LNCaP cells exhibited neurite outgrowth, androgenindependent proliferation and upregulation of mitogenic factors, and also showed elevation of Ca(v)3.2 expression or T-currents. Expression of cystathionine-gamma-Iyase (CSE) and cystathionine-beta-synthase (CBS), H2S-forming enzymes, and spontaneous secretion of PAP increased following the differentiation. The augmented T-currents were enhanced by H2S donors and suppressed by inhibitors of CSE, but not CBS. The PAP secretion was reduced by inhibition of CSE or T-type Ca2+ channels. During differentiation, Egr-1 and REST, positive and negative transcriptional regulators for Ca(v)3.2, were upregulated and downregulated, respectively, and Egr-1 knockdown prevented the Ca(v)3.2 overexpression. Our data suggest that, in neuroendocrine-differentiated LNCaP cells, H2S formed by the upregulated CSE promotes the activity of the upregulated Ca(v)3.2, leading to the elevated secretory functions. The overexpression of Ca(v)3.2 appears to involve upregulation of Egr-1 and downregulation of REST. (C) 2015 Elsevier Inc. All rights reserved.
  • Hydrogen sulfide and neuronal differentiation: Focus on Ca2+ channels, Kazuki Fukami, Atsufumi Kawabata, NITRIC OXIDE-BIOLOGY AND CHEMISTRY, NITRIC OXIDE-BIOLOGY AND CHEMISTRY, 46, 50 - 54, Apr. 2015 , Refereed
    Summary:Hydrogen sulfide (H2S) is considered the third gasotransmitter following nitric oxide (NO) and carbon monoxide (CO) in the mammalian body including the brain, heart, blood vessels, liver, kidney, pancreas, lung, gastrointestinal tract and reproductive organs. H2S is formed endogenously from L-cysteine by multiple enzymes, such as cystathionine-gamma-lyase, cystathionine-beta-synthase and 3-mercaptopyruvate sulfurtransferase in combination with cysteine aminotransferase, and participates in a variety of biological events through a number of target molecules. Exogenous and/or endogenous H2S enhances the activity of T-type Ca2+. channels in NG108-15 cells and isolated dorsal root ganglion neurons that abundantly express Ca(v)3.2, and in Ca(v)3.2-transfected HEK293 cells. Ca(v)3.2 mediates not only the H2S-induced enhancement of pain signals in nociceptor neurons, but also neuronal differentiation characterized by neuritogenesis and functional upregulation of high voltage-activated Ca2+. channels in NG108-15 cells. In this review, we focus on the functional modulation by H2S of primarily Ca(v)3.2 T-type Ca2+ channels and the molecular mechanisms underlying the H2S-induced neuronal differentiation. (C) 2015 Elsevier Inc. All rights reserved.
  • Mechanisms for proteinase-activated receptor 1-triggered prostaglandin E-2 generation in mouse osteoblastic MC3T3-E1 cells, Yuma Maeda, Fumiko Sekiguchi, Rumi Yamanaka, Ryo Sugimoto, Daichi Yamasoba, Shiori Tomita, Hiroyuki Nishikawa, Atsufumi Kawabata, BIOLOGICAL CHEMISTRY, BIOLOGICAL CHEMISTRY, 396(2), 153 - 162, Feb. 2015 , Refereed
    Summary:We analyzed signaling mechanisms for prostaglandin E-2 (PGE(2)) production following activation of proteinase-activated receptor-1 (PAR1), a thrombin receptor, in preosteoblastic MC3T3-E1 cells. PAR1 stimulation caused PGE(2) release, an effect suppressed by inhibitors ;of COX-1, COX-2, iPLA(2), cPLA(2), MAP kinases (MAPKs), Src, EGF receptor (EGFR) tyrosine kinase (EGFR-TK) and matrix metalloproteinase (MMP), but not by an intracellular Ca2+ chelator or inhibitors of PI3 kinase, protein kinase C (PKC) and NF-kappa B. PAR1 activation induced phosphorylation of MAPKs and upregulation of COX-2. The phosphorylation of p38 MAPK was suppressed by inhibitors of Src and EGFR-TK. The COX-2 upregulation was dependent on ERK, p38, EGFR-TK, Src, and COX-2 itself. PAR1 activation also induced MEK-dependent phosphorylation of cAMP response element binding protein (CREB). All inhibitors of EP1, EP2, EP3 and EP4 receptors suppressed the PAR1-triggered PGE(2) release. Exogenously applied PGE(2) facilitated PAR1-triggered COX-2 upregulation, but it alone had no effect. Together, the PAR1-mediated PGE(2) production in MC3T3-E1 cells appears to involve iPLA(2) and cPLA(2) for arachidonic acid release, and the MEK/ERK/CREB and Src/MMP/EGFR/p38 pathways for COX-2 upregulation, which is facilitated by endogenous PGE(2) formed by COX-2. These signaling mechanisms might underlie the role of the thrombin/PAR1/PGE(2) system in the early stage of the bone healing.
  • Roles of Ca(v)3.2 and TRPA1 Channels Targeted by Hydrogen Sulfide in Pancreatic Nociceptive Processing in Mice With or Without Acute Pancreatitis, Yuka Terada, Mayuko Fujimura, Sachiyo Nishimura, Maho Tsubota, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF NEUROSCIENCE RESEARCH, JOURNAL OF NEUROSCIENCE RESEARCH, 93(2), 361 - 369, Feb. 2015 , Refereed
    Summary:Hydrogen sulfide (H2S), formed by multiple enzymes, including cystathionine--lyase (CSE), targets Ca(v)3.2 T-type Ca2+ channels (T channels) and transient receptor potential ankyrin-1 (TRPA1), facilitating somatic pain. Pancreatitis-related pain also appears to involve activation of T channels by H2S formed by the upregulated CSE. Therefore, this study investigates the roles of the Ca(v)3.2 isoform and/or TRPA1 in pancreatic nociception in the absence and presence of pancreatitis. In anesthetized mice, AP18, a TRPA1 inhibitor, abolished the Fos expression in the spinal dorsal horn caused by injection of a TRPA1 agonist into the pancreatic duct. As did mibefradil, a T-channel inhibitor, in our previous report, AP18 prevented the Fos expression following ductal NaHS, an H2S donor. In the mice with cerulein-induced acute pancreatitis, the referred hyperalgesia was suppressed by NNC 55-0396 (NNC), a selective T-channel inhibitor; zinc chloride; or ascorbic acid, known to inhibit Ca(v)3.2 selectively among three T-channel isoforms; and knockdown of Ca(v)3.2. In contrast, AP18 and knockdown of TRPA1 had no significant effect on the cerulein-induced referred hyperalgesia, although they significantly potentiated the antihyperalgesic effect of NNC at a subeffective dose. TRPA1 but not Ca(v)3.2 in the dorsal root ganglia was downregulated at a protein level in mice with cerulein-induced pancreatitis. The data indicate that TRPA1 and Ca(v)3.2 mediate the exogenous H2S-induced pancreatic nociception in naive mice and suggest that, in the mice with pancreatitis, Ca(v)3.2 targeted by H2S primarily participates in the pancreatic pain, whereas TRPA1 is downregulated and plays a secondary role in pancreatic nociceptive signaling. (c) 2014 Wiley Periodicals, Inc.
  • Polaprezinc attenuates cyclophosphamide-induced cystitis and related bladder pain in mice, Masahiro Murakami-Nakayama, Maho Tsubota, Saki Hiruma, Fumiko Sekiguchi, Kenji Matsuyama, Takeshi Kimura, Masahiro Moriyama, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 127(2), 223 - 228, Feb. 2015 , Refereed
    Summary:Ca(v)3.2 T-type Ca2+ channels targeted by H2S, a gasotransmitter, participate in cyclophosphamide-induced cystitis and bladder pain. Given that zinc selectively inhibits Ca(v)3.2 among T-channel isoforms and also exhibits antioxidant activity, we examined whether polaprezinc (zinc-L-carnosine), a medicine for peptic ulcer treatment and zinc supplementation, reveals preventive or therapeutic effects on bladder inflammation and/or pain in the mouse with cyclophosphamide-induced cystitis, a model for interstitial cystitis. Systemic administration of cyclophosphamide caused cystitis-related symptoms including increased bladder weight and vascular permeability, and histological signs of bladder edema, accompanied by bladder pain-like nociceptive behavior/referred hyperalgesia. All these symptoms were significantly attenuated by oral preadministration of polaprezinc at 400 mg/kg. The same dose of polaprezinc also prevented the increased malondialdehyde level, an indicator of lipid peroxidation, and protein upregulation of cystathionine-gamma-Iyase. an H2S-generating enzyme, but not occludin, a tight junction-related membrane protein, in the bladder tissue of cyclophosphamide-treated mice. Oral posttreatment with polaprezinc at 30-100 mg/kg reversed the nociceptive behavior/referred hyperalgesia in a dose-dependent manner without affecting the increased bladder weight. Together, our data show that zinc supplementation with polaprezinc prevents the cyclophosphamide-induced cystitis probably through the antioxidant activity, and, like T-channel blockers, reverses the established cystitis-related bladder pain in mice, suggesting novel therapeutic usefulness of polaprezinc. (C) 2015 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.
  • Ouabain exerts cytoprotection by diminishing the intracellular K+ concentration increase caused by distinct stimuli in human leukemic cells, Masayuki Takechi, Tetsuyuki Wada, Hideki Yagi, Takashi Masuko, Atsufumi Kawabata, JOURNAL OF PHARMACY AND PHARMACOLOGY, JOURNAL OF PHARMACY AND PHARMACOLOGY, 67(1), 126 - 132, Jan. 2015 , Refereed
    Summary:Objectives We tested if modulation of cytosolic K+ levels by ouabain, an inhibitor of Na+/K+-ATPase, exerts cytoprotection against distinct stressful stimuli in human leukemic cells. Methods The cytosolic K+, Na+ or Ca2+ levels and the cytotoxicity were evaluated by flow cytometry. Key findings Various cytotoxic chemicals and ultraviolet irradiation induced cell death and increased intracellular concentrations of K+, Na+ or Ca2+. Ouabain reduced the cytotoxicity and the elevation of cytosolic levels of K+ but not those of Na+ or Ca2+. Conclusions Our data thus suggest that elevated cytosolic K+ levels are associated with the cytotoxicity in response to distinct stressful stimuli and that ouabain exerts cytoprotection most probably by regulating intracellular K+ levels.
  • Role of Hydrogen Sulfide, a Gasotransmitter, in Colonic Pain and Inflammation, Maho Tsubota, Atsufumi Kawabata, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, 134(12), 1245 - 1252, Dec. 2014 , Refereed
    Summary:Hydrogen sulfide (H2S), the third known gaseous transmitter following nitric oxide and carbon monoxide, is generated by multiple enzymes including cystathionine-gamma-lyase (CSE) in vivo. We previously demonstrated that H2S activates Ca(v)3.2 T-type Ca2+ channels expressed on sensory neurons, leading to hyperalgesia and facilitation of inflammation. Here, we describe the role of H2S in processing of colonic pain and inflammation. Intracolonic (i.col.) administration of NaHS, an H2S donor, to mice evoked colonic pain-like nociceptive behavior and referred hyperalgesia accompanied by phosphorylation of ERK in the superficial layers of spinal dorsal horn, a marker for excitation of nociceptive neurons. The pronociceptive effect of NaHS was abolished by inhibitors or knockdown of Ca(v)3.2 and by an inhibitor of TRPA1, another target molecule of H2S. In rats with colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS), on the other hand, repeated i.col. administration of NaHS prevented colonic ulcer and inflammatory symptoms, which were inhibited by ablation of capsaicin-sensitive sensory neurons or T-type Ca2+ channel inhibitor. NaHS, given i.col., caused phosphorylation of ERK in the spinal dorsal horn of rats with TNBS-induced colitis, but not of naive rats. In TNBS-treated rats, Ca(v)3.2 was upregulated in the dorsal root ganglia, while CSE was downregulated in the colon. Taken together, these findings suggest that inhibitors of the CSE/H2S/Ca(v)3.2 or TRPA1 pathways might be useful for the treatment of colonic pain diseases such as irritable bowel syndrome, while H2S donors or Ca(v)3.2 activators might be useful for the treatment of inflammatory bowel disease including Crohn's disease.
  • Bladder pain relief by HMGB1 neutralization and soluble thrombomodulin in mice with cyclophosphamide-induced cystitis, Junichi Tanaka, Kaoru Yamaguchi, Hiroyasu Ishikura, Maho Tsubota, Fumiko Sekiguchi, Yukari Seki, Toshifumi Tsujiuchi, Akira Murai, Takehiro Umemura, Atsufumi Kawabata, NEUROPHARMACOLOGY, NEUROPHARMACOLOGY, 79, 112 - 118, Apr. 2014 , Refereed
    Summary:High mobility group box 1 (HMGB1), one of damage-associated molecular patterns (DAMPs), plays roles in not only inflammation but also processing of somatic pain. Given that no evidence for roles of HMGB1 in visceral pain signaling is available, we asked if HMGB1 participates in bladder pain accompanying cystitis caused by cyclophosphamide in mice, using the anti-HMGB1 neutralizing antibody and recombinant human soluble thrombomodulin (rhsTM) that sequesters HMGB1 and promotes its degradation by thrombin. Cyclophosphamide, administered i.p., caused bladder pain-like nociceptive behavior and referred hyperalgesia accompanying cystitis symptoms including increased bladder weight, an indicator of edema, in mice. The cyclophosphamide-induced bladder pain and referred hyperalgesia, but not increased bladder weight, were prevented by i.p. preadministration of the anti-HMGB1 neutralizing antibody or rhsTM. HMGB1, given i.p., facilitated the bladder pain and referred hyperalgesia caused by a subeffective dose of cyclophosphamide, an effect blocked by rhsTM. In the cyclophosphamide-treated mice, HMGB1 levels greatly decreased in the bladder tissue, particularly in the urothelial cells, but did not change in the plasma. Low molecular weight heparin, known to inhibit the receptor for advanced glycation end products (RAGE), but not lipopolysaccharide from Rhodobacter sphaeroides, an inhibitor of toll-like receptor 4 (TLR4), blocked the cyclophosphamide-induced bladder pain and referred hyperalgesia. Thus, our data indicate involvement of HMGB1 in the cyclophosphamide-induced bladder pain signaling, but not cystitis itself, and suggest that targeting HMGB1 with rhsTM or blocking RAGE might serve as a novel therapeutic strategy for the management of bladder pain. (C) 2013 Elsevier Ltd. All rights reserved.
  • Endogenous and exogenous hydrogen sulfide facilitates T-type calcium channel currents in Ca(v)3.2-expressing HEK293 cells, Fumiko Sekiguchi, Yosuke Miyamoto, Daiki Kanaoka, Hiroki Ide, Shigeru Yoshida, Tsuyako Ohkubo, Atsufumi Kawabata, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 445(1), 225 - 229, Feb. 2014 , Refereed
    Summary:Hydrogen sulfide (H2S), a gasotransmitter, is formed from L-cysteine by multiple enzymes including cystathionine-gamma-lyase (CSE). We have shown that an H2S donor, NaHS, causes hyperalgesia in rodents, an effect inhibited by knockdown of Ca(v)3.2 T-type Ca2+ channels (T-channels), and that NaHS facilitates T-channel-dependent currents (T-currents) in NG108-15 cells that naturally express Ca(v)3.2. In the present study, we asked if endogenous and exogenous H2S participates in regulation of the channel functions in Ca(v)3.2-transfected HEK293 (Ca(v)3.2-HEK293) cells. DL-Propargylglycine (PPG), a CSE inhibitor, significantly decreased T-currents in Ca(v)3.2-HEK293 cells, but not in NG108-15 cells. NaHS at 1.5 mM did not affect T-currents in Ca(v)3.2-HEK293 cells, but enhanced T-currents in NG108-15 cells. In the presence of PPG, NaHS at 1.5 mM, but not 0.1-0.3 mM, increased T-currents in Ca(v)3.2-HEK293 cells. Similarly, Na2S, another H2S donor, at 0.1-0.3 mM significantly increased T-currents in the presence, but not absence, of PPG in Ca(v)3.2-HEK293 cells. Expression of CSE was detected at protein and mRNA levels in HEK293 cells. Intraplantar administration of Na2S, like NaHS, caused mechanical hyperalgesia, an effect blocked by NNC 55-0396, a T-channel inhibitor. The in vivo potency of Na2S was higher than NaHS. These results suggest that the function of Ca(v)3.2 T-channels is tonically enhanced by endogenous H2S synthesized by CSE in Ca(v)3.2-HEK293 cells, and that exogenous H2S is capable of enhancing Ca(v)3.2 function when endogenous H2S production by CSE is inhibited. In addition, Na2S is considered a more potent H2S donor than NaHS in vitro as well as in vivo. (C) 2014 Elsevier Inc. All rights reserved.
  • Contribution of TRPA1 as a Downstream Signal of Proteinase-Activated Receptor-2 to Pancreatic Pain, Yuka Terada, Mayuko Fujimura, Sachiyo Nishimura, Maho Tsubota, Fumiko Sekiguchi, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 123(3), 284 - 287, Nov. 2013 , Refereed
    Summary:We examined if TRPA1, like TRPV1, contributes to pancreatic nociceptor excitation following proteinase-activated receptor-2 (PAR2) stimulation and to pancreatitis-related pain in mice. A PAR2-activating peptide, infused into the pancreatic duct, caused spinal Fos expression, which was prevented by AP18, a TRPA1 inhibitor. Repeated administration of cerulein caused referred hyperalgesia accompanying pancreatitis, which was reversed by SB366791, a TRPV1 inhibitor, but not AP18. AP18, administered in combination with a subeffective dose of SB366791, significantly suppressed the referred hyperalgesia. Our findings suggest that TRPA1, like TRPV1, mediates PAR2-triggered pancreatic nociception and that TRPA1 in collaboration with TRPV1 latently contributes to pancreatitis-related pain.
  • Inhibition by Hydrogen Sulfide of Rabbit Platelet Aggregation and Calcium Mobilization, Hiroyuki Nishikawa, Hitomi Hayashi, Satoko Kubo, Maho Tsubota-Matsunami, Fumiko Sekiguchi, Atsufumi Kawabata, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 36(8), 1278 - 1282, Aug. 2013 , Refereed
    Summary:Hydrogen sulfide (H2S), a gasotransmitter, plays a variety of roles in the mammalian body including the cardiovascular system. Given evidence that H2S donors including NaHS inhibit human platelet aggregation, we examined and characterized the effects of NaFIS on rabbit platelet aggregation and cytosolic Ca2+ mobilization. Rabbit platelet aggregation was determined in platelet-rich plasma (PRP) and washed platelets. Intracellular Ca2+ levels were monitored in Fura2-loaded washed platelets. NaHS prevented rabbit platelet aggregation induced by collagen or ADP, and the effective concentration range of NaHS was 0.1-0.3 mM in PRP and 1-3 mM in washed platelets. In washed platelets, NaHS attenuated cytosolic Ca2+ mobilization induced by collagen or ADP and also reduced platelet aggregation induced by ionomycin, a Ca2+ ionophore. The antiplatelet effect of NaHS was blocked by an adenylyl cyclase inhibitor and enhanced by a phosphodiesterase inhibitor. H2S thus suppresses rabbit platelet aggregation by interfering with both upstream and downstream signals of cytosolic Ca2+ mobilization in a cAMP-dependent manner.
  • T-type Calcium Channels: Functional Regulation and Implication in Pain Signaling, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 122(4), 244 - 250, Aug. 2013 , Refereed
    Summary:Low-voltage-activated T-type Ca2+ channels (T-channels), especially Ca(v)3.2 among the three isoforms (Ca(v)3.1, Ca(v)3.2, and Ca(v)3.3), are now considered to play pivotal roles in processing of pain signals. Ca(v)3.2 T-channels are functionally modulated by extracellular substances such as hydrogen sulfide and ascorbic acid, by intracellular signaling molecules including protein kinases, and by glycosylation. Ca(v)3.2 T-channels are abundantly expressed in both peripheral and central endings of the primary afferent neurons, regulating neuronal excitability and release of excitatory neurotransmitters such as substance P and glutamate, respectively. Functional upregulation of Ca(v)3.2 T-channels is involved in the pathophysiology of inflammatory, neuropathic, and visceral pain. Thus, Ca(v)3.2 T-channels are considered to serve as novel targets for development of drugs for treatment of intractable pain resistant to currently available analgesics.
  • AKAP-dependent sensitization of Cav3.2 channels via the EP4 receptor/cAMP pathway mediates PGE2-induced mechanical hyperalgesia, Fumiko Sekiguchi, Yuka Aoki, Maiko Nakagawa, Daiki Kanaoka, Yuta Nishimoto, Maho Tsubota-Matsunami, Rumi Yamanaka, Shigeru Yoshida, Atsufumi Kawabata, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 168(3), 734 - 745, Feb. 2013 , Refereed
    Summary:Background and Purpose The Cav3.2 isoform of T-type Ca2+ channels (T channels) is sensitized by hydrogen sulfide, a pro-nociceptive gasotransmitter, and also by PKA that mediates PGE2-induced hyperalgesia. Here we examined and analysed Cav3.2 sensitization via the PGE2/cAMP pathway in NG108-15 cells that express Cav3.2 and produce cAMP in response to PGE2, and its impact on mechanical nociceptive processing in rats. Experimental Approach In NG108-15 cells and rat dorsal root ganglion (DRG) neurons, T-channel-dependent currents (T currents) were measured with the whole-cell patch-clamp technique. The molecular interaction of Cav3.2 with A-kinase anchoring protein 150 (AKAP150) and its phosphorylation were analysed by immunoprecipitation/immunoblotting in NG108-15 cells. Mechanical nociceptive threshold was determined by the paw pressure test in rats. Key Results In NG108-15 cells and/or rat DRG neurons, dibutyryl cAMP (db-cAMP) or PGE2 increased T currents, an effect blocked by AKAP St-Ht31 inhibitor peptide (AKAPI) or KT5720, a PKA inhibitor. The effect of PGE2 was abolished by RQ-00015986-00, an EP4 receptor antagonist. AKAP150 was co-immunoprecipitated with Cav3.2, regardless of stimulation with db-cAMP, and Cav3.2 was phosphorylated by db-cAMP or PGE2. In rats, intraplantar (i.pl.) administration of db-cAMP or PGE2 caused mechanical hyperalgesia, an effect suppressed by AKAPI, two distinct T-channel blockers, NNC 55-0396 and ethosuximide, or ZnCl2, known to inhibit Cav3.2 among T channels. Oral administration of RQ-00015986-00 suppressed the PGE2-induced mechanical hyperalgesia. Conclusion and Implications Our findings suggest that PGE2 causes AKAP-dependent phosphorylation and sensitization of Cav3.2 through the EP4 receptor/cAMP/PKA pathway, leading to mechanical hyperalgesia in rats.
  • Involvement of the endogenous hydrogen sulfide/Cav3.2 T-type Ca2+channel pathway in cystitis-related bladder pain in mice, Maho Matsunami, Takahiro Miki, Kanae Nishiura, Yuko Hayashi, Yasumasa Okawa, Hiroyuki Nishikawa, Fumiko Sekiguchi, Lisa Kubo, Tomoka Ozaki, Toshifumi Tsujiuchi, Atsufumi Kawabata, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 167(4), 917 - 928, Oct. 2012 , Refereed
    Summary:BACKGROUND AND PURPOSE Hydrogen sulfide (H2S), generated by enzymes such as cystathionine-?-lyase (CSE) from L-cysteine, facilitates pain signals by activating the Cav3.2 T-type Ca2+ channels. Here, we assessed the involvement of the CSE/H2S/Cav3.2 pathway in cystitis-related bladder pain. EXPERIMENTAL APPROACH Cystitis was induced by i.p. administration of cyclophosphamide in mice. Bladder pain-like nociceptive behaviour was observed and referred hyperalgesia was evaluated using von Frey filaments. Phosphorylation of ERK in the spinal dorsal horn was determined immunohistochemically following intravesical administration of NaHS, an H2S donor. KEY RESULTS Cyclophosphamide caused cystitis-related symptoms including increased bladder weight, accompanied by nociceptive changes (bladder pain-like nociceptive behaviour and referred hyperalgesia). Pretreatment with DL-propargylglycine, an inhibitor of CSE, abolished the nociceptive changes and partly prevented the increased bladder weight. CSE protein in the bladder was markedly up-regulated during development of cystitis. Mibefradil or NNC 550396, blockers of T-type Ca2+ channels, administered after the symptoms of cystitis appeared, reversed the nociceptive changes. Further, silencing of Cav3.2 protein by repeated intrathecal administration of mouse Cav3.2-targeting antisense oligodeoxynucleotides also significantly attenuated the nociceptive changes, but not the increased bladder weight. Finally, the number of cells staining positive for phospho-ERK was increased in the superficial layer of the L6 spinal cord after intravesical administration of NaHS, an effect inhibited by NNC 550396. CONCLUSION AND IMPLICATIONS Endogenous H2S, generated by up-regulated CSE, caused bladder pain and referred hyperalgesia through the activation of Cav3.2 channels, one of the T-type Ca2+ channels, in mice with cyclophosphamide-induced cystitis.
  • Hydrogen sulfide-induced mechanical hyperalgesia and allodynia require activation of both Cav3.2 and TRPA1 channels in mice, Kazumasa Okubo, Midori Matsumura, Yudai Kawaishi, Yuka Aoki, Maho Matsunami, Yasumasa Okawa, Fumiko Sekiguchi, Atsufumi Kawabata, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 166(5), 1738 - 1743, Jul. 2012 , Refereed
    Summary:BACKGROUND AND PURPOSE Hydrogen sulfide, a gasotransmitter, facilitates somatic pain signals via activation of Cav3.2 T-type calcium channels in rats. Given evidence for the activation of transient receptor potential ankyrin-1 (TRPA1) channels by H2S, we asked whether TRPA1 channels, in addition to Cav3.2 channels, contribute to the H2S-induced mechanical hyperalgesia and allodynia in mice. EXPERIMENTAL APPROACH Mechanical hyperalgesia and allodynia were evaluated by the von Frey test in mice. Cav3.2 or TRPA1 channels in the sensory neurons were silenced by repeated intrathecal administration of antisense oligodeoxynucleotides in mice. KEY RESULTS Intraplantar administration of NaHS evoked hyperalgesia and allodynia in mice, an effect attenuated or abolished by NNC 550396 or mibefradil, T-type calcium channel blockers, and by ascorbic acid or zinc chloride, known to selectively inhibit Cav3.2 channels, out of the three isoforms of T-type calcium channels. Silencing of Cav3.2 channels in the sensory neurons also prevented the NaHS-induced hyperalgesia and allodynia in mice. The NaHS-induced hyperalgesia and allodynia in mice were significantly suppressed by AP18, a TRPA1 channel blocker, and by silencing of TRPA1 channels in the sensory neurons. CONCLUSIONS AND IMPLICATIONS Mechanical hyperalgesia and allodynia induced by NaHS/H2S required activation of both Cav3.2 and TRPA1 channels in mice.
  • Colonic Hydrogen Sulfide-Induced Visceral Pain and Referred Hyperalgesia Involve Activation of Both Ca(v)3.2 and TRPA1 Channels in Mice, Maho Tsubota-Matsunami, Yumi Noguchi, Yasumasa Okawa, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 119(3), 293 - 296, Jul. 2012 , Refereed
    Summary:Luminal hydrogen sulfide (H2S), a gasotransmitter, causes colonic pain / referred hyperalgesia in mice, most probably via activation of T-type Ca2+ channels. Here we analyzed the mechanisms for H2S-induced facilitation of colonic pain signals. Intracolonic administration of NaHS, an H2S donor, evoked visceral pain-like nociceptive behavior and referred hyperalgesia in mice, an effect abolished by NNC 55-0396, a selective T-type Ca2+-channel blocker, or by knockdown of Ca(v)3.2. AP18, a TRPA1 blocker, also prevented the NaHS-induced colonic pain and referred hyperalgesia. These findings demonstrate that H2S-induced colonic pain and referred hyperalgesia require activation of both Ca(v)3.2 and TRPA1 channels in mice.
  • Topical application of disodium isostearyl 2-O-L-ascorbyl phosphate, an amphiphilic ascorbic acid derivative, reduces neuropathic hyperalgesia in rats, Kazumasa Okubo, Hiroki Nakanishi, Maho Matsunami, Hiroharu Shibayama, Atsufumi Kawabata, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 166(3), 1058 - 1068, Jun. 2012 , Refereed
    Summary:BACKGROUND AND PURPOSE Cav3.2 T-type calcium channels, targeted by H2S, are involved in neuropathic hyperalgesia in rats and ascorbic acid inhibits Cav3.2 channels. Therefore, we evaluated the effects of intraplantar (i.pl.) administration of ascorbic acid or topical application of disodium isostearyl 2-O-L-ascorbyl phosphate (DI-VCP), a skin-permeable ascorbate derivative on hyperalgesia induced by NaHS, an H2S donor, and on neuropathic hyperalgesia. EXPERIMENTAL APPROACH In rats mechanical hyperalgesia was evoked by i.pl. NaHS, and neuropathic hyperalgesia was induced by L5 spinal nerve cutting (L5SNC) or by repeated administration of paclitaxel, an anti-cancer drug. Dermal ascorbic acid levels were determined colorimetrically. KEY RESULTS The NaHS-evoked Cav3.2 channel-dependent hyperalgesia was inhibited by co-administered ascorbic acid. Topical application of DI-VCP, but not ascorbic acid, prevented the NaHS-evoked hyperalgesia, and also increased dermal ascorbic acid levels. Neuropathic hyperalgesia induced by L5SNC or paclitaxel was reversed by i.pl. NNC 550396, a selective T-type calcium channel blocker, ascorbic acid or DI-VCP, and by topical DI-VCP, but not by topical ascorbic acid. The effects of i.pl. ascorbic acid and topical DI-VCP in the paclitaxel-treated rats were characterized by the faster onset and greater magnitude, compared with their effects in the L5SNC rats. Dermal ascorbic acid levels in the hindpaw significantly decreased after paclitaxel treatment, but not L5SNC, which was reversed by topical DI-VCP. CONCLUSIONS AND IMPLICATIONS Ascorbic acid, known to inhibit Cav3.2 channels, suppressed neuropathic hyperalgesia. DI-VCP ointment for topical application may be of benefit in the treatment of neuropathic pain.
  • Involvement of ERK in NMDA receptor-independent cortical neurotoxicity of hydrogen sulfide, Yuko Kurokawa, Fumiko Sekiguchi, Satoko Kubo, Yoshiko Yamasaki, Sachi Matsuda, Yukari Okamoto, Teruki Sekimoto, Anna Fukatsu, Hiroyuki Nishikawa, Toshiaki Kume, Nobuyuki Fukushima, Akinori Akaike, Atsufumi Kawabata, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 414(4), 727 - 732, Nov. 2011 , Refereed
    Summary:Hydrogen sulfide (H(2)S), a gasotransmitter, exerts both neurotoxicity and neuroprotection, and targets multiple molecules including NMDA receptors, T-type calcium channels and NO synthase (NOS) that might affect neuronal viability. Here, we determined and characterized effects of NaHS, an H(2)S donor, on cell viability in the primary cultures of mouse fetal cortical neurons. NaHS caused neuronal death, as assessed by LDH release and trypan blue staining, but did not significantly reduce the glutamate toxicity. The neurotoxicity of NaHS was resistant to inhibitors of NMDA receptors, T-type calcium channels and NOS, and was blocked by inhibitors of MEK, but not JNK, p38 MAP kinase, PKC and Src. NaHS caused prompt phosphorylation of ERK and upregulation of Bad, followed by translocation of Bax to mitochondria and release of mitochondrial cytochrome c(1) leading to the nuclear condensation/fragmentation. These effects of NaHS were suppressed by the MEK inhibitor. Our data suggest that the NMDA receptor-independent neurotoxicity of H(2)S involves activation of the MEK/ERK pathway and some apoptotic mechanisms. (C) 2011 Elsevier Inc. All rights reserved.
  • Prostaglandin E-2 and Pain-An Update, Atsufumi Kawabata, BIOLOGICAL & PHARMACEUTICAL BULLETIN, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 34(8), 1170 - 1173, Aug. 2011 , Refereed
    Summary:Prostaglandin E-2 (PGE(2)), a cyclooxygenase (COX) product, is the best known lipid mediator that contributes to inflammatory pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), inhibitors of COX-1 and/or COX-2, suppress inflammatory pain by reducing generation of prostanoids, mainly PGE(2), while they exhibit gastrointestinal, renal and cardiovascular toxicities. Selective inhibitors of microsomal PGE synthase-1 and subtype-selective antagonists of PGE(2) receptors, particularly EP1 and EP4, may be useful as analgesics with minimized side-effects. Protein kinase C (PKC) and PKA downstream of EP1 and EP4, respectively, sensitize/activate multiple molecules including transient receptor potential vanilloid-1 (TRPV1) channels, purinergic P2X3 receptors, and voltage-gated calcium or sodium channels in nociceptors, leading to hyperalgesia. PGE(2) is also implicated in neuropathic and visceral pain and in migraine. Thus, PGE(2) has a great impact on pain signals, and pharmacological intervention in upstream and downstream signals of PGE(2) may serve as novel therapeutic strategies for the treatment of intractable pain.
  • INHIBITION OF T-TYPE CALCIUM CHANNELS AND HYDROGEN SULFIDE-FORMING ENZYME REVERSES PACLITAXEL-EVOKED NEUROPATHIC HYPERALGESIA IN RATS, K. Okubo, T. Takahashi, F. Sekiguchi, D. Kanaoka, M. Matsunami, T. Ohkubo, J. Yamazaki, N. Fukushima, S. Yoshida, A. Kawabata, NEUROSCIENCE, NEUROSCIENCE, 188, 148 - 156, Aug. 2011
    Summary:Hydrogen sulfide (H,S), a gasotransmitter, facilitates pain sensation by targeting Ca(v)3.2 T-type calcium channels. The H(2)S/Ca(v)3.2 pathway appears to play a role in the maintenance of surgically evoked neuropathic pain. Given evidence that chemotherapy-induced neuropathic pain is blocked by ethosuximide, known to block T-type calcium channels, we examined if more selective T-type calcium channel blockers and also inhibitors of cystathionine-gamma-lyase (CSE), a major H(2)S-forming enzyme in the peripheral tissue, are capable of reversing the neuropathic pain evoked by paclitaxel, an anti-cancer drug. It was first demonstrated that T-type calcium channel blockers, NNC 55-0396, known to inhibit Ca(v)3.1, and mibefradil inhibited T-type currents in Ca(v)3.2-transfected HEK293 cells. Repeated systemic administration of paclitaxel caused delayed development of mechanical hyperalgesia, which was reversed by single intraplantar administration of NNC 550396 or mibefradil, and by silencing of Ca(v)3.2 by antisense oligodeoxynucleotides. Systemic administration of DL-propargylglycine and p-cyanoalanine, irreversible and reversible inhibitors of CSE, respectively, also abolished the established neuropathic hyperalgesia. In the paclitaxel-treated rats, upregulation of Ca(v)3.2 and CSE at protein levels was not detected in the dorsal root ganglia (DRG), spinal cord or peripheral tissues including the hindpaws, whereas H(2)S content in hindpaw tissues was significantly elevated. Together, our study demonstrates the effectiveness of NNC 55-0396 in inhibiting Ca(v)3.2, and then suggests that paclitaxel-evoked neuropathic pain might involve the enhanced activity of T-type calcium channels and/or CSE in rats, but not upregulation of Ca(v)3.2 and CSE at protein levels, differing from the previous evidence for the neuropathic pain model induced by spinal nerve cutting in which Ca(v)3.2 was dramatically upregulated in DRG. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
  • ONO-8130, a selective prostanoid EP1 receptor antagonist, relieves bladder pain in mice with cyclophosphamide-induced cystitis, Takahiro Miki, Maho Matsunami, Saori Nakamura, Hiroki Okada, Hidekazu Matsuya, Atsufumi Kawabata, PAIN, PAIN, 152(6), 1373 - 1381, Jun. 2011 , Refereed
    Summary:Given the previous evidence for involvement of prostanoid EP1 receptors in facilitation of the bladder afferent nerve activity and micturition reflex, the present study investigated the effect of ONO-8130, a selective EP1 receptor antagonist, on cystitis-related bladder pain in mice. Cystitis in mice was produced by intraperitoneal administration of cyclophosphamide at 300 mg/kg. Bladder pain-like nociceptive behavior and referred hyperalgesia were assessed in conscious mice. Phosphorylation of extracellular signal-regulated kinase (ERK) in the L6 spinal cord was determined by immunohistochemistry in anesthetized mice. Cyclophosphamide treatment caused bladder pain-like nociceptive behavior and referred hyperalgesia accompanying cystitis symptoms, including increased bladder weight and vascular permeability and upregulation of cyclooxygenase-2 in the bladder tissue. Oral preadministration of ONO-8130 at 0.3-30 mg/kg strongly prevented both the bladder pain-like behavior and referred hyperalgesia in a dose-dependent manner, but had slight effect on the increased bladder weight and vascular permeability. Oral ONO-8130 at 30 mg/kg also reversed the established cystitis-related bladder pain. Intravesical administration of prostaglandin E-2 caused prompt phosphorylation of ERK in the L6 spinal cord, an effect blocked by ONO-8130. Our findings strongly suggest that the prostaglandin E-2/EP1 system participates in processing of cystitis-related bladder pain, and that EP1 antagonists including ONO-8130 are useful for treatment of bladder pain, particularly in interstitial cystitis. (C) 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
  • Delayed Production of Arachidonic Acid Contributes to the Delay of Proteinase-Activated Receptor-1 (PAR1)-Triggered Prostaglandin E-2 Release in Rat Gastric Epithelial RGM1 Cells, Fumiko Sekiguchi, Ai Ohi, Yuma Maeda, Kaori Takaoka, Teruki Sekimoto, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF CELLULAR BIOCHEMISTRY, JOURNAL OF CELLULAR BIOCHEMISTRY, 112(3), 909 - 915, Mar. 2011 , Refereed
    Summary:Proteinase-activated receptor-1 (PAR I), upon activation, exerts prostanoid-dependent gastroprotection, and increases prostaglandin E-2 (PGE(2)) release through cyclooxygenase-2 (COX-2) upregulation in rat gastric mucosal epithelial RGM1 cells. However, there is a big time lag between the PAR I-triggered PG E2 release and COX-2 upregulation in RGM1 cells; that is, the former event takes 18 h to occur, while the latter rapidly develops and reaches a plateau in 6 h. The present study thus aimed at clarifying mechanisms for the delay of PGE2 release after PAR activation in RGM1 cells. Although a PAR1-activating peptide, TFLLR-NH2, alone caused PGE2 release at 18 h, but not 6 h, TFLLR-NH2 in combination with arachidonic acid dramatically enhanced PGE(2) release even for 1-6 h. TFLLR-NH2 plus linoleic acid caused a similar rapid response. CP-24879, a Delta(5)/Delta(6)-desaturase inhibitor, abolished the PGE(2) release induced by TFLLR-NH2 plus linoleic acid, but not by TFLLR-NH2 alone. The TFLLR-NH2-induced PGE2 release was not affected by inhibitors of cytosolic phospholipase A(2) (cPLA(2)), Ca2+-independent PLA(2) (cPLA2) or secretory PLA(2) (sPLA(2)), but was abolished by their mixture or a pan-PLA(2) inhibitor. Among PLA2 isozymes, mRNA of group IIA sPLA(2) (sPLA(2)-IIA) was upregulated following PAR1 stimulation for 6-18 h, whereas protein levels of PGE synthases were unchanged. These data suggest that the delay of PG E2 release after COX-2 upregulation triggered by PAR1 is due to the poor supply of free arachidonic acid at the early stage in RGM1 cells, and that plural isozymes of PLA2 including sPLA2-IIA may complementarily contribute to the liberation of free arachidonic acid. J. Cell. Biochem. 112: 909-915,2011. (C) 2010 Wiley-Liss, Inc.
  • Phosphorylation of ERK in the Spinal Dorsal Horn Following Pancreatic Pronociceptive Stimuli With Proteinase-Activated Receptor-2 Agonists and Hydrogen Sulfide in Rats: Evidence for Involvement of Distinct Mechanisms, Osamu Fukushima, Sachiyo Nishimura, Maho Matsunami, Yuka Aoki, Hiroyuki Nishikawa, Hiroyasu Ishikura, Atsufumi Kawabata, JOURNAL OF NEUROSCIENCE RESEARCH, JOURNAL OF NEUROSCIENCE RESEARCH, 88(14), 3198 - 3205, Nov. 2010 , Refereed
    Summary:Noxious stimuli cause prompt phosphorylation of extracellular signal-regulated kinase (ERK) in the spinal dorsal horn that contributes to facilitation of pain sensation and is often used as an immediate marker for excitation of spinal neurons following somatic and colonic nociception. Here we asked whether two distinct pronociceptive stimuli with proteinase-activated receptor-2 (PAR2) agonists and hydrogen sulfide (H(2)S) in the pancreas cause phosphorylation of ERK in the spinal dorsal horn and also examined involvement of their possible downstream signaling molecules, transient receptor potential vanilloid-1 (TRPV1) and T-type Ca(2+) channels, respectively. Capsaicin (a TRPV1 agonist), trypsin (an endogenous PAR2 agonist), SLIGRL-NH(2) (a PAR2-activating peptide), and NaHS (an H2S donor) were infused into the pancreatic duct in anesthetized rats, and phosphorylated ERK in the spinal cord was detected by immunohistochemistry. Intraductal administration of capsaicin and trypsin caused prompt phosphorylation of ERK in the superficial layers of T9, but not T5 or T12, spinal dorsal horn. SLIGRL-NH(2) and NaHS, administered in the same manner, also produced ERK phosphorylation in the corresponding spinal regions. Mibefradil, a T-type Ca(2+) channel blocker, abolished the phosphorylation of ERK caused by intraductal NaHS but not SLIGRL-NH(2). In contrast, capsazepine, an inhibitor of TRPV1, suppressed the phosphorylation of ERK caused by intraductal SLIGRL-NH(2) but not NaHS. Our data thus demonstrate that pancreatic pronociceptive stimuli with PAR2 agonists and H(2)S cause ERK phosphorylation in the spinal dorsal horn, through activation of TRPV1 and T-type Ca(2+) channels, respectively, and that those two pronociceptive pathways are independent of each other. (c) 2010 Wiley-Liss, Inc.
  • The proteinase/proteinase-activated receptor-2/transient receptor potential vanilloid-1 cascade impacts pancreatic pain in mice, Sachiyo Nishimura, Hiroyasu Ishikura, Maho Matsunami, Yui Shinozaki, Fumiko Sekiguchi, Mitsuhide Naruse, Taisuke Kitamura, Ryukichi Akashi, Kenji Matsumura, Atsufumi Kawabata, LIFE SCIENCES, LIFE SCIENCES, 87(19-22), 643 - 650, Nov. 2010 , Refereed
    Summary:Aims: Proteinase-activated receptor-2 (PAR2) and transient receptor potential vanilloid-1 (TRPV1) are co-localized in the primary afferents, and the trans-activation of TRPV1 by PAR2 activation is involved in processing of somatic pain. Given evidence for contribution of PAR2 to pancreatic pain, the present study aimed at clarifying the involvement of TRPV1 in processing of pancreatic pain by the proteinase/PAR2 pathway in mice. Main methods: Acute pancreatitis was created by repeated administration of cerulein in conscious mice, and the referred allodynia/hyperalgesia was assessed using von Frey filaments. Injection of PAR2 agonises into the pancreatic duct was achieved in anesthetized mice, and expression of Fos in the spinal cord was determined by immunohistochemistry. Key findings: The established referred allodynia/hyperalgesia following cerulein treatment was abolished by post-treatment with nafamostat mesilate, a proteinase inhibitor, and with capsazepine, a TRPV1 antagonist, in mice. Injection of trypsin, an endogenous PAR2 agonist, or SLIGRL-NH(2), a PAR2-activating peptide, into the pancreatic duct caused expression of Fos protein in the spinal superficial layers at T8-T10 levels in the mice. The spinal Fos expression caused by trypsin and by SLIGRL-NH(2) was partially blocked by capsazepine, the former effect abolished by nafamostat mesilate. Significance: Our data thus suggest that the proteinase/PAR2/TRPV1 cascade might impact pancreatic pain, in addition to somatic pain, and play a role in the maintenance of pancreatitis-related pain in mice. (C) 2010 Elsevier Inc. All rights reserved.
  • Upregulation of Ca(v)3.2 T-type calcium channels targeted by endogenous hydrogen sulfide contributes to maintenance of neuropathic pain, Tomoko Takahashi, Yuka Aoki, Kazumasa Okubo, Yumi Maeda, Fumiko Sekiguchi, Kenji Mitani, Hiroyuki Nishikawa, Atsufumi Kawabata, PAIN, PAIN, 150(1), 183 - 191, Jul. 2010 , Refereed
    Summary:Hydrogen sulfide (H2S) formed from L-cysteine by multiple enzymes including cystathionine-gamma-lyase (CSE) is now considered a gasotransmitter in the mammalian body. Our previous studies have shown that H2S activates/sensitizes Ca(v)3.2 T-type Ca2+ channels, leading to facilitation of somatic and visceral nociception, and that CSE-derived endogenous H2S participates in inflammatory pain. Here, we show novel evidence for involvement of the endogenous H2S-Ca(v)3.2 pathway in neuropathic pain. In the rat subjected to the right L5 spinal nerve cutting (L5SNC), a neuropathic pain model, i.p. administration of DL-propargylglycine (PPG) and beta-cyanoalanine, irreversible and reversible CSE inhibitors, respectively, strongly suppressed the neuropathic hyperalgesia/allodynia. The anti-hyperalgesic effect of PPG was reversed by intraplantar administration of NaHS, a donor for H2S, in the L5SNC rat. Intraplantar administration or topical application of mibefradil, a T-type Ca2+ channel blocker, reversed hyperalgesia in the L5SNC rat. The protein levels of Ca(v)3.2, but not CSE, in the ipsilateral L4, L5 and L6 dorsal root ganglia were dramatically upregulated in the L5SNC rat. Finally, silencing of Ca(v)3.2 in DRG by repeated intrathecal administration of Ca(v)3.2-targeting siRNA significantly attenuated the neuropathic hyperalgesia in the L5SNC rat. In conclusion, our data suggest that Ca(v)3.2 T-type Ca2+ channels in sensory neurons are upregulated and activated/sensitized by CSE-derived endogenous H2S after spinal nerve injury, contributing to the maintenance of neuropathic pain. We thus propose that Ca(v)3.2 and CSE could be targets for the development of therapeutic drugs for the treatment of neuropathic pain. (C) 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
  • Involvement of Src kinase in T-type calcium channel-dependent neuronal differentiation of NG108-15 cells by hydrogen sulfide, Takeshi Tarui, Kazuki Fukami, Keita Nagasawa, Shigeru Yoshida, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF NEUROCHEMISTRY, JOURNAL OF NEUROCHEMISTRY, 114(2), 512 - 519, Jul. 2010 , Refereed
    Summary:P>Hydrogen sulfide (H(2)S), a gasotransmitter, induces neuronal differentiation characterized by neuritogenesis and functional up-regulation of high voltage-activated Ca2+ channels, via activation of T-type Ca2+ channels in NG108-15 cells. We thus analyzed signaling mechanisms for the H(2)S-evoked neuronal differentiation. NaHS, a donor for H(2)S, facilitated T-type Ca2+ channel-dependent membrane currents, an effect blocked by ascorbic acid that selectively inhibits Ca(v)3.2 among three T-type channel isoforms. NaHS, applied once at a high concentration (13.5 mM) or repetitively at a relatively low concentration (1.5 mM), as well as ionomycin, a Ca2+ ionophore, evoked neuritogenesis. The neuritogenesis induced by NaHS, but not by ionomycin, was abolished by mibefradil, a T-type Ca2+ channel blocker. PP2, a Src kinase inhibitor, completely suppressed the neuritogenesis caused by NaHS or ionomycin, while it only partially blocked neuritogenesis caused by dibutyryl cAMP, a differentiation inducer. NaHS, but not dibutyryl cAMP, actually caused phosphorylation of Src, an effect blocked by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl, an intracellular Ca2+ chelator, mibefradil or ascorbic acid. The up-regulation of high voltage-activated currents in the cells treated with NaHS was also inhibited by PP2. Together, our data reveal that Src kinase participates in the T-type Ca2+ channel-dependent neuronal differentiation caused by NaHS/H(2)S in NG108-15 cells.
  • Opposite effects of two thiazolidinediones, ciglitazone and troglitazone, on proteinase-activated receptor-1-triggered prostaglandin E-2 release, Kaori Takaoka, Fumiko Sekiguchi, Hidenori Shigi, Yuma Maeda, Hiroyuki Nishikawa, Atsufumi Kawabata, TOXICOLOGY, TOXICOLOGY, 268(1-2), 40 - 45, Jan. 2010 , Refereed
    Summary:Thiazolidinediones, known as peroxisome proliferator-activated receptor-gamma (PPAR gamma) agonists, may modify prostaglandin formation and exert gastroprotective effects. Since activation of proteinase-activated receptor-1 (PAR1) reveals endogenous prostanoid-dependent gastroprotection, we investigated if two thiazolidinediones, ciglitazone and troglitazone, modulate the prostaglandin E-2 (PGE(2)) release caused by activation of PAR1 in normal rat gastric mucosal epithelial RGM1 cells. Ciglitazone dramatically facilitated the PAR1-triggered PGE(2) production and cyclooxygenase-2 (COX-2) upregulation, although it had no effect by itself. In contrast, troglitazone suppressed the PARI-triggered PGE2 production and COX-2 upregulation. Either effect of ciglitazone and troglitazone was resistant to GW9662, a PPAR gamma antagonist. The facilitation of the PGE(2) release by ciglitazone was blocked by inhibitors of MEK, p38 MAP kinase (p38MAPK) and PI3-kinase (PI3K), but not JNK. Nonetheless, ciglitazone failed to enhance the PAR1-triggered phosphorylation of ERK and p38MAPK. In conclusion, ciglitazone and troglitazone, exert opposite effects on the PARI-triggered PGE(2) production and COX-2 upregulation by targeting molecules other than PPAR gamma. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Proteinase-Activated Receptor-2-Triggered Prostaglandin E-2 Release, but Not Cyclooxygenase-2 Upregulation, Requires Activation of the Phosphatidylinositol 3-Kinase/Akt/Nuclear Factor-kappa B Pathway in Human Alveolar Epithelial Cells, Kazumi Moriyuki, Fumiko Sekiguchi, Kaori Matsubara, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 111(3), 269 - 275, Nov. 2009 , Refereed
    Summary:Proteinase-activated receptor-2 (PAR2) triggers upregulation of cyclooxygenase-2 (COX-2) and prostaglandin E-2 (PGE(2)) formation in human alveolar epithelial A549 cells. This COX-2 upregulation appears to involve the Src/epidermal growth factor (EGF) receptor/p38 MAP kinase (p38MAPK) pathway and also the cAMP-response element-binding protein (CREB) pathway. Here, we investigated the roles of nuclear factor-kappa B (NF-kappa B)-related signals in the PAR2-triggered PGE(2) release/COX-2 upregulation in A549 cells. The PAR2-triggered PGE2 release was clearly blocked by an inhibitor of the NF-kappa B pathway. Stimulation of PAR2 actually caused phosphorylation of inhibitor-kappa B, an indicator of NF-kappa B activation, an effect being blocked by inhibitors of MEK, phosphatidylinositol 3-kinase (PI3-kinase), and Akt, but little or not by inhibitors of p38MAPK and JNK. Stimulation of PAR2 also caused phosphorylation of Akt, an effect suppressed by inhibitors of PI3-kinase and MEK. Nonetheless, the PAR2-triggered upregulation of COX-2 was resistant to inhibitors of NF-kappa B, PI3-kinase, and Akt, but was attenuated by inhibitors of MEK and JNK. Stimulation of PAR2 induced phosphorylation of CREB, an effect abolished by an inhibitor of MEK but not inhibitors of p38MAPK and EGF receptor. These findings demonstrate that the MEK / ERK / PI3-kinase / Akt / NF-kappa B pathway is involved in PAR2-triggered PGE2 formation, but not upregulation of COX-2 that is dependent on activation of ERK/CREB and JNK in addition to p38MAPK.
  • Rhodanese, but not cystathionine-gamma-lyase, is associated with dextran sulfate sodium-evoked colitis in mice: A sign of impaired colonic sulfide detoxification?, Eiichi Taniguchi, Maho Matsunami, Takeshi Kimura, Daiki Yonezawa, Tsuyoshi Ishiki, Fumiko Sekiguchi, Hiroyuki Nishikawa, Yuma Maeda, Hiroyasu Ishikura, Atsufumi Kawabata, TOXICOLOGY, TOXICOLOGY, 264(1-2), 96 - 103, Oct. 2009 , Refereed
    Summary:Clinical studies suggest that colonic luminal hydrogen sulfide (H(2)S), produced by sulfate-reducing bacteria or through other pathways, might be involved in the pathogenesis of inflammatory bowel disease (IBD). Nonetheless, this hypothesis has been poorly investigated by basic studies using laboratory animals. We thus focused on two enzymes, cystathionine-gamma-lyase (CSE) that generates H(2)S from L-cysteine, and rhodanese that directly or indirectly detoxifies H(2)S, particularly in relation to the colitis induced by dextran sulfate sodium (DSS) in mice. CSE was a major H(2)S-forming enzyme in colonic and renal homogenates from mice and rats, and the rhodanese activity was also detectable in both tissues. Colitis-related symptoms including decreased body weight gain, diarrhea, hematochezia and shortening of colon length were observed in the mice drinking DSS. Those symptoms were not or only slightly attenuated by repeated administration of a CSE inhibitor. CSE activity and protein levels in the colonic tissue did not notably change in the mice with colitis. In contrast, the activity and protein/mRNA levels of rhodanese in the colon, but not kidney, significantly decreased nearly in parallel with the development of colitis, followed by elevation of rhodanese activity in red blood cells (RBCs). These data show that rhodanese, but not CSE, is associated with DSS-induced colitis in mice, leading to a hypothesis that impaired detoxification of H(2)S due to down-regulation or suppression of colonic rhodanese is involved in IBD. The delayed enhancement of rhodanese activity in RBCs, a possible compensative event, might be available as a disease marker for IBD. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Novel antagonists for proteinase-activated receptor 2: inhibition of cellular and vascular responses in vitro and in vivo, T. Kanke, M. Kabeya, S. Kubo, S. Kondo, K. Yasuoka, J. Tagashira, H. Ishiwata, M. Saka, T. Furuyama, T. Nishiyama, T. Doi, Y. Hattori, A. Kawabata, M. R. Cunningham, R. Plevin, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 158(1), 361 - 371, Sep. 2009
    Summary:Background and purpose: Proteinase-activated receptor 2 (PAR(2)) is a G-protein coupled receptor associated with many pathophysiological functions. To date, the development of PAR(2) antagonists has been limited. Here, we identify a number of novel peptide-mimetic PAR(2) antagonists and demonstrate inhibitory effects on PAR(2)-mediated intracellular signalling pathways and vascular responses. Experimental approach: The peptide-mimetic compound library based on the structures of PAR(2) agonist peptides were screened for inhibition of PAR(2)-induced calcium mobilisation in human keratinocytes. Representative compounds were further evaluated by radioligand binding and inhibition of NF kappa B transcriptional activity and IL-8 production. The vascular effects of the antagonists were assessed using in vitro and in vivo models. Key results: Two compounds, K-12940 and K-14585, significantly reduced SLIGKV-induced Ca(2+) mobilisation in primary human keratinocytes. Both K-12940 and K-14585 exhibited competitive inhibition for the binding of a high-affinity radiolabelled PAR(2)-ligand, [(3)H]-2-furoyl-LIGRL-NH(2), to human PAR(2) with K(i) values of 1.94 and 0.627 mu M respectively. NF kappa B reporter activity and IL-8 production were also significantly reduced. Furthermore, relaxation of rat-isolated aorta induced by SLIGRL-NH(2) was inhibited competitively by K-14585. K-14585 also significantly lowered plasma extravasation in the dorsal skin of guinea pigs and reduced salivation in mice. Conclusions and implications: K-12940 and K-14585 antagonized PAR(2) competitively, resulting in inhibition of PAR(2)-mediated signalling and physiological responses both in vitro and in vivo. These peptide-mimetic PAR(2) antagonists could be useful in evaluating PAR(2)-mediated biological events and might lead to a new generation of therapeutically useful antagonists. British Journal of Pharmacology ( 2009) 158, 361-371; doi: 10.1111/j.1476-5381.2009.00342.x
  • Hydrogen sulfide as a novel mediator for pancreatic pain in rodents, S. Nishimura, O. Fukushima, H. Ishikura, T. Takahashi, M. Matsunami, T. Tsujiuchi, F. Sekiguchi, M. Naruse, Y. Kamanaka, A. Kawabata, GUT, GUT, 58(6), 762 - 770, Jun. 2009
    Summary:Objective: Hydrogen sulfide (H(2)S) is formed from L-cysteine by multiple enzymes including cystathionine-gamma-lyase (CSE) in mammals, and plays various roles in health and disease. Recently, a pronociceptive role for H(2)S in the processing of somatic pain was identified. Here, the involvement of H(2)S in pancreatic pain is examined. Methods: Anaesthetised rats or mice received an injection of NaHS, a donor for H(2)S, or capsaicin into the pancreatic duct, and the expression of spinal Fos protein was detected by immunohistochemistry. Pancreatitis was created by 6 hourly doses of caerulein in unanaesthetised mice, and pancreatitis-related allodynia/hyperalgesia was evaluated using von Frey hairs. CSE activity and protein levels in pancreatic tissues were measured using the colorimetric method and western blotting, respectively. Results: Either NaHS or capsaicin induced the expression of Fos protein in the superficial layers of the T8 and T9 spinal dorsal horn of rats or mice. The induction of Fos by NaHS but not capsaicin was abolished by mibefradil, a T-type Ca(2+) channel blocker. In conscious mice, repeated doses of caerulein produced pancreatitis accompanied by abdominal allodynia/hyperalgesia. Pretreatment with an inhibitor of CSE prevented the allodynia/hyperalgesia, but not the pancreatitis. A single dose of mibefradil reversed the established pancreatitis-related allodynia/hyperalgesia. Either the activity or protein expression of pancreatic CSE increased after the development of caerulein-induced pancreatitis in mice. Conclusions: The data suggest that pancreatic NaHS/H(2)S most probably targets T-type Ca(2+) channels, leading to nociception, and that endogenous H(2)S produced by CSE and possibly T-type Ca(2+) channels are involved in pancreatitis-related pain.
  • Luminal hydrogen sulfide plays a pronociceptive role in mouse colon, M. Matsunami, T. Tarui, K. Mitani, K. Nagasawa, O. Fukushima, K. Okubo, S. Yoshida, M. Takemura, A. Kawabata, GUT, GUT, 58(6), 751 - 761, Jun. 2009
    Summary:Objective: Given recent evidence that hydrogen sulfide (H(2)S), a gasotransmitter, promotes somatic pain through redox modulation of T-type Ca(2+) channels, the roles of colonic luminal H(2)S in visceral nociceptive processing in mice were examined. Methods: After intracolonic administration of NaHS, an H(2)S donor, visceral pain-like behaviour and referred abdominal allodynia/hyperalgesia were evaluated. Phosphorylation of extracellular signal-regulated protein kinase (ERK) in the spinal dorsal horn was determined immunohistochemically. The whole-cell recording technique was used to evaluate T-type Ca(2+) currents (T-currents) in cultured dorsal root ganglion (DRG) neurons. Results: Like capsaicin, NaHS, administered intracolonically at 0.5-5 nmol per mouse, triggered visceral nociceptive behaviour accompanied by referred allodynia/hyperalgesia in mice. Phosphorylation of ERK in the spinal dorsal horn was detected following intracolonic NaHS or capsaicin. The behavioural effects of intracolonic NaHS were abolished by a T-type channel blocker or an oxidant, but not inhibitors of L-type Ca(2+) channels or ATP-sensitive K(+) (K(ATP)) channels. Intraperitoneal NaHS at 60 mu mol/kg facilitated intracolonic capsaicin-evoked visceral nociception, an effect abolished by the T-type channel blocker, although it alone produced no behavioural effect. In DRG neurons, T-currents were enhanced by NaHS. Conclusions: These findings suggest that colonic luminal H(2)S/NaHS plays pronociceptive roles, and imply that the underlying mechanisms might involve sensitisation/activation of T-type channels probably in the primary afferents, aside from the issue of the selectivity of mibefradil.
  • Hyperalgesia induced by spinal and peripheral hydrogen sulfide: Evidence for involvement of Ca(v)3.2 T-type calcium channels, Yumi Maeda, Yuka Aoki, Fumiko Sekiguchi, Maho Matsunami, Tomoko Takahashi, Hiroyuki Nishikawa, Atsufumi Kawabata, PAIN, PAIN, 142(1-2), 127 - 132, Mar. 2009 , Refereed
    Summary:Hydrogen sulfide (H2S), a gasotransmitter, facilitates membrane currents through T-type Ca2+ channels, and intraplantar (i.pl.) administration of NaHS, a donor of H2S, causes prompt hyperalgesia in rats. In this. context, we asked whether intrathecal (i.t.) administration of NaHS could mimic the hyperalgesic effect of i.pl. NaHS in rats, and then examined if Ca(v)3.2 isoform of T-type Ca2+ channels contributed to the pronociceptive effects of i.t. and i.pl. NaHS. Either i.t. or i.pl. administration of NaHS rapidly decreased nociceptive threshold in rats, as determined by the paw pressure method. The hyperalgesia caused by i.t. and i.pl. NaHS was abolished by co-administration of mibefradil, a pan-T-type Ca2+ channel inhibitor, and also Suppressed by pretreatment with i.t. and i.pl, zinc chloride, known to preferentially inhibit Ca(v)3.2 among T-type Ca2+ channel isoforms, respectively. Repeated i.t. administration of antisense oligodeoxynucleotides (ODNs) targeting rat Cav3.2, but not mismatch ODNs, caused silencing of Ca(v)3.2 protein in the dorsal root ganglia and spinal cord, and then attenuated the hyperalgesia induced by either i.t. or i.pl, NaHS. Our findings thus establish that spinal and peripheral NaHS/H2S activates or sensitizes Ca(v)3.2 T-type Ca2+ channels expressed in the primary afferents and/or spinal nociceptive neurons, leading to sensitization of nociceptive processing and hyperalgesia. (C) 2008 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
  • Hydrogen sulfide evokes neurite outgrowth and expression of high-voltage-activated Ca2+ currents in NG108-15 cells: involvement of T-type Ca2+ channels, Keita Nagasawa, Takeshi Tarui, Shigeru Yoshida, Fumiko Sekiguchi, Maho Matsunami, Ai Ohi, Kazuki Fukami, Seiji Ichida, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF NEUROCHEMISTRY, JOURNAL OF NEUROCHEMISTRY, 108(3), 676 - 684, Feb. 2009 , Refereed
    Summary:We investigated if stimulation of T-type Ca2+ channels with sodium hydrosulfide (NaHS), a donor of hydrogen sulfide (H2S), could cause neuronal differentiation of NG108-15 cells. Like dibutyryl cyclic AMP (db-cAMP), treatment with NaHS at 1.5-13.5 mM for 16 h enhanced neurite outgrowth in a concentration-dependent manner. Synergistic neuritogenic effect was obtained in the cells stimulated with NaHS in combination with db-cAMP at subeffective concentrations. Exposure to NaHS or db-cAMP for 2 days resulted in enhancement of expression of high-voltage-activated currents consisting of N-, P/Q-, L- and also other types, but not of T-type currents. Mibefradil, a pan-T-type channel blocker, abolished the neuritogenesis induced by NaHS, but not by db-cAMP. The NaHS-evoked neuritogenesis was also completely blocked by pretreatment with BAPTA/AM, a chelator of intracellular Ca2+, and by zinc chloride at a concentration known to selectively inhibit Ca(v)3.2 isoform of T-type Ca2+ channels, but not Ca(v)3.1 or Ca(v)3.3. Further, l-ascorbate, recently proven to selectively inhibit Ca(v)3.2, abolished the neuritogenic effect of NaHS, but not db-cAMP. Our data thus demonstrate that NaHS/H2S is a novel inducer of neuronal differentiation in NG108-15 cells, as characterized by neuritogenesis and expression of high-voltage-activated currents, and suggest the involvement of T-type Ca2+ channels, especially Ca(v)3.2.
  • PAR2 triggers IL-8 release via MEK/ERK and PI3-kinase/Akt pathways in GI epithelial cells, Yusuke Tanaka, Fumiko Sekiguchi, Hao Hong, Atsufumi Kawabata, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 377(2), 622 - 626, Dec. 2008 , Refereed
    Summary:Proteinase-activated receptor-2 (PAR2) plays pro-inflammatory roles in many organs including the gastrointestinal (GI) tract. To clarify the downstream pro-inflammatory signaling of PAR2 in the GI tract, we examined interleukin-8 (IL-8) release and the underlying cellular signaling following PAR2 stimulation in human colorectal cancer-derived HCT-15 cells and human gastric adenocarcinoma-derived MKN-45 cells. A PAR2-activating peptide, but not a PAR2-inactive scrambled peptide or a PAR1 - activating peptide, caused IL-8 elease in these GI epithelial cells. The PAR2-triggered IL-8 release was suppressed by inhibitors of MEK (U0126) or PI3-kinase (LY294002), and PAR2 stimulation indeed activated the downstream kinases, ERK and Akt. U0126 blocked the phosphorylation of ERK, but not Akt, and LY294002 blocked the phosphorylation of Akt, but not ERK. Together, PAR2 triggers IL-8 release via two independent signaling pathways, MEK/ERK and PI3-kinase/Akt, suggesting a role of PAR2 as a pro-inflammatory receptor in the GI tract. (C) 2008 Elsevier Inc. All rights reserved.
  • Basic and Translational Research on Proteinase-Activated Receptors: Preface, Katsuya Hirano, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 108(4), 406 - 407, Dec. 2008 , Refereed
  • Evidence that PAR2-triggered prostaglandin E-2 (PGE(2)) formation involves the ERK-cytosolic phospholipase A(2)-COX-1-microsomal PGE synthase-1 cascade in human lung epithelial cells, Mami Nagataki, Kazumi Moriyuki, Fumiko Sekiguchi, Atsufumi Kawabata, CELL BIOCHEMISTRY AND FUNCTION, CELL BIOCHEMISTRY AND FUNCTION, 26(2), 279 - 282, Mar. 2008 , Refereed
    Summary:We investigated possible involvement of three isozymes of prostaglandin E synthase (PGES), microsomal PGES-1 (mPGES-1), mPGES-2 and cytosolic PGES (cPGES) in COX-2-dependent prostaglandin E-2 (PGE(2)) formation following proteinase-activated receptor-2 (PAR2) stimulation in human lung epithelial cells. PAR2 stimulation up-regulated mPGES-1 as well as COX-2, but not mPGES-2 or cPGES, leading to PGE2 formation. The PAR2-triggered up-regulation of mPGES-1 was suppressed by inhibitors of COX-1, cytosolic phospholipase A(2) (cPLA(2)) and MEK, but not COX-2. Finally, a selective inhibitor of mPGES-1 strongly suppressed the PAR2-evoked PGE(2) formation. PAR2 thus appears to trigger specific up-regulation of mPGES-1 that is dependent on prostanoids formed via the MEK/ERK/cPLA(2)/COX-1 pathway, being critical for PGE(2) formation. Copyright (c) 2007 John Wiley & Sons, Ltd.
  • Gastrointestinal roles for proteinase-activated receptors in health and disease, A. Kawabata, M. Matsunami, F. Sekiguchi, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 153, S230 - S240, Mar. 2008
    Summary:It has been almost a decade since the molecular cloning of all four members of the proteinase-activated receptor ( PAR) family was completed. This unique family of G protein-coupled receptors (GPCRs) mediates specific cellular actions of various endogenous proteinases including thrombin, trypsin, tryptase, etc. and also certain exogenous enzymes. Increasing evidence has been clarifying the emerging roles played by PARs in health and disease. PARs, particularly PAR1 and PAR2, are distributed throughout the gastrointestinal (GI) tract, modulating various GI functions. One of the most important GI functions of PARs is regulation of exocrine secretion in the salivary glands, pancreas and GI mucosal epithelium. PARs also modulate motility of GI smooth muscle, involving multiple mechanisms. PAR2 appears to play dual roles in pancreatitis and related pain, being pro-inflammatory/pro-nociceptive and anti-inflammatory/anti-nociceptive. Similarly, dual roles for PAR1 and PAR2 have been demonstrated in mucosal inflammation/damage throughout the GI tract. There is also fundamental and clinical evidence for involvement of PAR2 in colonic pain. PARs are thus considered key molecules in regulation of GI functions and targets for development of drugs for treatment of various GI diseases.
  • Novel functions of hydrogen sulfide through T-type calcium channels: its involvement in pain processing, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 106, 47P - 47P, 2008 , Refereed
  • Involvement of endogenous hydrogen sulfide and T-type calcium channels in neuropathic pain, Tomoko Takahashi, Yumi Maeda, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 106, 63P - 63P, 2008 , Refereed
  • Effects of hydrogen sulfide on platelet aggregation and calcium mobilization in rabbits, Hitomi Hayashi, Satoko Kubo, Hiroyuki Nishikawa, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 106, 95P - 95P, 2008 , Refereed
  • Cell signaling for interleukin-8 release caused by PAR2 stimulation in human colorectal cancer and human gastric adenocarcinoma cells, Yusuke Tanaka, Hao Hong, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 106, 101P - 101P, 2008 , Refereed
  • Characterization of inhibition of rat platelet aggregation by hydrogen sulfide, an endogenous gas messenger, Satoko Kubo, Hitomi Hayashi, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 106, 169P - 169P, 2008 , Refereed
  • Intracellular signaling for delayed prostaglandin E-2 production caused by proteinase-activated receptor-1 stimulation in rat gastric mucosal epithelial cells, Furniko Sekiguchi, Ai Ohi, Kaori Takaoka, Hiroyuki Nishikawa, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 106, 211P - 211P, 2008 , Refereed
  • Thiazolidinediones modulate PAR1-triggered prostaglandin E-2 production via PPAR gamma-independent mechanisms in rat normal gastric mucosal epithelial cells, Kaori Takaoka, Hidenori Shigi, Fumiko Sekiguchi, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 106, 211P - 211P, 2008 , Refereed
  • Signal transduction for formation/release of interleukin-8 caused by a PAR2-activating peptide in human lung epithelial cells, Kazumi Moriyuki, Mami Nagataki, Fumiko Sekiguchi, Hiroyuki Nishikawa, Atsufumi Kawabata, REGULATORY PEPTIDES, REGULATORY PEPTIDES, 145(1-3), 42 - 48, Jan. 2008 , Refereed
    Summary:Proteinase-activated receptor-2 (PAR2) plays a dual role in the respiratory system, being pro- and anti-inflammatory. In human lung epithelial cells (A549), PAR2 activation causes release of interleukin-8 (IL-8) in addition to prostaglandin E-2 (PGE(2)). In the present study, we thus investigated PAR2-triggered signal transduction pathways causing IL-8 formation in A549 cells. SLIGRL-NH2, a PAR2-activating peptide, but not LSIGRL-NH2,, a scrambled peptide, elicited release of IL-8 from A549 cells for 18 h, as measured by the ELISA method, an effect being suppressed by inhibitors of MEK, JNK, EGF receptor-tyrosine kinase (EGFR-TK), Src, pan-tyrosine kinases and protein kinase C, but not p38 MAP kinase or cyclooxygenase. SLIGRL-NH2, also up-regulated IL-8 at protein and mRNA levels, as determined by Western blotting and RTPCR, respectively. The PAR2-triggered up-regulation of IL-8 protein and mRNA was blocked by an inhibitor of MEK, but not clearly by inhibitors of JNK and EGFR-TK. SLIGRL-NH2 actually phosphorylated JNK as well as ERK, the JNK activation being resistant to inhibitors of Src, pan-tyrosine kinases, protein kinase C and EGFR-TK. Our data suggest that PAR2-triggerd IL-8 formation involves transcriptional upregulation of IL-8 via the MEK-ERK pathway, while the JNK and EGF receptor pathways might rather contribute to a post-transcriptional process for the release of IL-8. (c) 2007 Elsevier B.V. All rights reserved.
  • Hydrogen sulfide inhibits activity of three isoforms of recombinant nitric oxide synthase, Atoko Kubo, Yuko Kurokawa, Ichiko Doe, Takashi Masuko, Fumiko Sekiguchi, Atsufumi Kawabata, TOXICOLOGY, TOXICOLOGY, 241(1-2), 92 - 97, Nov. 2007 , Refereed
    Summary:To clarify the presence of cross-talk between H2S and NO, we investigated effect of NaHS, an H2S donor, on activity of recombinant NO synthase (NOS) isoforms. Activity of all nNOS, iNOS and eNOS was inhibited by NaHS (IC50: 0.13-0.21 mM). In contrast, Na2SO3, L-Cysteine and threo-1,4-dimercapto-2,3-butanediol, a reductant, exerted poor inhibition of NOS activity. Increasing concentrations of tetrahydrobiopterin (BH4) reversed the NaHS inhibition of nNOS and eNOS, but not iNOS. Our data thus demonstrate inhibition of three NOS isoforms by NaHS/H2S, and suggest involvement of interaction of NaHS/H2S with BH4 in inhibition of nNOS and eNOS, but not iNOS. (C) 2007 Elsevier Ireland Ltd. All rights reserved.
  • A protective role of hydrogen sulfide against oxidative stress in rat gastric mucosal epithelium, Daiki Yonezawa, Fumiko Sekiguchi, Misato Miyamoto, Eiichi Taniguchi, Masami Honjo, Takashi Masuko, Hiroyuki Nishikawa, Atsufumi Kawabata, TOXICOLOGY, TOXICOLOGY, 241(1-2), 11 - 18, Nov. 2007 , Refereed
    Summary:We investigated effect of hydrogen sulfide (H2S) on oxidative stress-caused cell death in gastric mucosal epithelial cells. In rat normal gastric epithelial RGM1 cells, NaHS, a H2S donor, at 1.5 mM strongly suppressed hydrogen peroxide (H2O2)-caused cell death, while it slightly augmented the H2O2 toxicity at 0.5-1 mM. The protective effect of NaHS was abolished by inhibitors of MEK or JNK, but not of p38 MAP kinase. NaHS at 1.5 mM actually phosphorylated ERK and JNK in RGM1 cells. Glibenclamide, an ATP-sensitive K+ (K-ATP(+)) channel inhibitor, did not affect the protective effect of NaHS, although mRNAs for K(ATP)(+)channel subunits, Kir6.1 and SUR1, were detected in RGM1 cells. In anesthetized rats, oral administration of NaHS protected against gastric mucosal lesion caused by ischemia-reperfusion. These results suggest that NaHS/H2S may protect gastric mucosal epithelial cells against oxidative stress through stimulation of MAP kinase pathways, a therapeutic dose range being very narrow. (C) 2007 Elsevier Ireland Ltd. All rights reserved.
  • Hydrogen sulfide as a novel nociceptive messenger, Atsufumi Kawabata, Tsuyoshi Ishiki, Kelta Nagasawa, Shigeru Yoshida, Yumi Maeda, Tomoko Takahashi, Fumiko Sekiguchi, Tetsuyuki Wada, Seiji Ichida, Hiroyuki Nishikawa, PAIN, PAIN, 132(1-2), 74 - 81, Nov. 2007 , Refereed
    Summary:Hydrogen sulfide (H2S), an endogenous gasotransmitter, modulates various biological events such as inflammation in the mammalian body. The present study investigated possible involvement of H2S in peripheral nociceptive processing. Intraplantar (i.pl.) administration of NaHS, a H2S donor, produced prompt hyperalgesia in rats, accompanied by expression of Fos in the spinal dorsal horn. The H2S-evoked hyperalgesia was blocked by 5,5'-dithio-bis-(2-nitrobenzoic acid) (DTNB), an oxidizing agent, or ethosuximide and mibefradil, T-type Ca2+ channel inhibitors. L-Cysteine, an endogenous source for H2S, given i.pl., also elicited hyperalgesia, an effect being abolished by DL-propargylglycine (PPG) and beta-cyanoalanine (BCA), inhibitors of cystathionine-gamma-lyase, a H2S synthesizing enzyme. PPG and/or BCA partially inhibited the hyperalgesia induced by i.pl. lipopolysaccharide, an effect being reversed by i.pl. NaHS. In the patch-clamp study using undifferentiated NG108-15 cells that express T-type, but not other types, of Ca2+ channels, NaHS enhanced the currents through the T-type channels, an effect being blocked by DTNB. Thus, H2S appears to function as a novel nociceptive messenger through sensitization of T-type Ca2+ channels in the peripheral tissues, particularly during inflammation. (C) 2007 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
  • Roles for H2S in pain processing: Response to Cunha and Verri, Atsufumi Kawabata, PAIN, PAIN, 130(3), 302 - 303, Aug. 2007
  • Hydrogen sulfide causes relaxation in mouse bronchial smooth muscle, Satoko Kubo, Ichiko Doe, Yuko Kurokawa, Atsufumi Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 104(4), 392 - 396, Aug. 2007 , Refereed
    Summary:We investigated the effects of NaHS, a hydrogen sulfide (H2S) donor, on the tension of isolated mouse and guinea-pig bronchial rings. NaHS at 0.01-10 mM had no effect on the tone of those preparations without precontraction. When the preparation was precontracted with carbachol, NaHS at 0.1-3 mM strongly relaxed the mouse rings, but produced only slight relaxation in the guinea-pig rings. The NaHS-induced relaxation in the mouse bronchus was resistant to inhibitors of ATP-sensitive K+ channels, soluble guanylyl cyclase, cyclooxygenase (COX)-1 or COX-2, and antagonists of tachykinin receptors. Thus, NaHS evokes bronchodilation in mice, suggesting a possible role for H2S in the respiratory system.
  • The proteinase inhibitor camostat mesilate suppresses pancreatic pain in rodents, Hiroyasu Ishikura, Sachiyo Nishimura, Maho Matsunami, Toshifumi Tsujiuchi, Tsuyoshi Ishiki, Fumiko Sekiguchi, Mitsuhide Naruse, Toshio Nakatani, Yoshihisa Kamanaka, Atsufumi Kawabata, LIFE SCIENCES, LIFE SCIENCES, 80(21), 1999 - 2004, May 2007 , Refereed
    Summary:Camostat mesilate, an orally available proteinase inhibitor, is clinically used for treatment of pancreatitis. Given recent evidence that pancreatic proteinases including trypsin and/or proteinase-activated receptor-2 (PAR2) might be involved in pancreatic pain, we examined if camostat mesilate could suppress spinal Fos expression, a marker for neuronal activation, following specific application of trypsin to the pancreas, and pancreatitis-related referred allodynia. Trypsin, administered into the pancreatic duct, caused delayed expression of Fos proteins in the superficial layer of the bilateral T8 and T9 spinal dorsal horns in rats. The trypsin-induced spinal Fos expression was completely abolished by oral preadministration of camostat mesilate at 300 mg/kg. After hourly repeated (6 times in total) administration of caerulein, mice showed typical symptoms of pancreatitis, accompanied by mechanical allodynia in the upper abdomen (i.e., referred hyperalgesia/allodynia), as assessed by use of von Frey filaments. Camostat mesilate at 100-300 mg/kg, given orally twice before the 1st and 4th doses of cacrulein, abolished the pancreatitis-related abdominal allodynia, while it partially prevented the inflammatory signs. The same doses of camostat mesilate, when administered once after the final dose of caerulein, also revealed significant anti-allodynic effect. These data suggest that camostat mesilate prevents and/or depresses pancreatitis-induced pain and/or referred hyperalgesia/allodynia, in which proteinases including trypsin would play a critical role. (C) 2007 Elsevier Inc. All rights reserved.
  • Direct inhibition of endothelial nitric oxide synthase by hydrogen sulfide: Contribution to dual modulation of vascular tension, Satoko Kubo, Ichiko Doe, Yuko Kurokawa, Hiroyuki Nishikawa, Atsufumi Kawabata, TOXICOLOGY, TOXICOLOGY, 232(1-2), 138 - 146, Mar. 2007 , Refereed
    Summary:We characterized actions of hydrogen sulfide (H2S) on tension of isolated rat and mouse aortae, and then examined if H2S could directly modulate activity of endothelial nitric oxide (NO) synthase (eNOS). Isometric tension was recorded in rat and mouse aortic rings. Activity of recombinant bovine eNOS was determined as conversion of [H-3]-arginine into [H-3]-citrulline. NaHS, a H2S donor, caused contraction at low concentrations and relaxation at high concentrations in both rat and mouse aortae precontracted with phenylephrine. The contractile and relaxant effects of NaHS were enhanced and partially blocked, respectively, by the K-ATP(+) channel inhibitor glibenclamide in the rat, but not mouse, aortae. In the KCl-precontracted rat aorta, NaHS produced glibenclamide-resistant contraction and relaxation. NaHS produced only relaxation, but not contraction, in the endothelium-denuded aortae, and also in the endothelium-intact aortae in the presence of inhibitors of NOS or soluble guanylate cyclase. NaHS pretreatment greatly attenuated the relaxation induced by acetylcholine, but not by an NO donor, in the tissues. Finally, we found that NaHS inhibited the conversion of [H-3]-arginine into [H-3]-citrulline by recombinant eNOS. NaHS thus causes contraction and relaxation in rat and mouse aortae. K-ATP(+) channels are considered to contribute only partially to the NaHS-evoked relaxation. Most interestingly, our data demonstrate direct inhibition of eNOS by NaHS, probably responsible for its contractile activity, being evidence for a novel function of H2S. (c) 2007 Elsevier Ireland Ltd. All rights reserved.
  • Mechanisms for prostaglandin E-2 formation caused by proteinase-activated receptor-1 activation in rat gastric mucosal epithelial cells, Fumiko Sekiguchi, Shino Saito, Kaori Takaoka, Hitomi Hayashi, Mami Nagataki, Keita Nagasawa, Hiroyuki Nishikawa, Hirofumi Matsui, Atsufumi Kawabata, BIOCHEMICAL PHARMACOLOGY, BIOCHEMICAL PHARMACOLOGY, 73(1), 103 - 114, Jan. 2007 , Refereed
    Summary:Proteinase-activated receptor-1 (PAR1), a thrombin receptor, plays a protective role in gastric mucosa via prostanoid formation. Thus, we studied effects of PAR1 stimulation on prostaglandin E-2 (PGE(2)) formation in rat normal gastric mucosal epithelial RGM1 cells and analyzed the underlying signal transduction mechanisms. The PARI-activating peptide (PAR1-AP) and thrombin increased PGE(2) release from RGM1 cells for 18 h, an effect being suppressed by inhibitors of COX-1, COX-2, MEK, p38 MAP kinase (p38 MAPK), protein kinase C (PKC), Src and EGF receptor-tyrosine kinase (EGFR-TK), but not JNK and matrix metalloproteinase (MMP)/a disintegrin and metalloprotemases (ADAMs). PAR1-AP caused persistent (6 h or more) and transient (5 min) phosphorylation of ERK and p38 MAPK, respectively, followed by delayed reinforcement at 18 h. PAR1-AP up-regulated COX-2 in a manner dependent on MEK and EGFR-TK, but not p38 MAPK. The PARI-mediated persistent ERK phosphorylation was reduced by inhibitors of Src and EGFR-TK. PAR1-AP actually phosphorylated EGF receptors and up-regulated mRNA for heparin-binding-EGF (HB-EGF), the latter effect being blocked by inhibitors of Src, EGFR-TK and MEK. Heparin, an inhibitor for HB-EGF, suppressed PAR1-mediated PGE2 formation and persistent ERK phosphorylation. These results suggest that PAR1 up-regulates COX-2 via persistent activation of MEK/ERK that is dependent on EGFR-TK activation following induction of HB-EGF, leading to PGE(2) formation. In addition, our data also indicate involvement of COX-1, PKC and p38 MAPK in PAR1-triggered PGE(2) formation. PAR1, thus stimulates complex multiple signaling pathways responsible for PGE(2) formation in RGM1 cells. (c) 2006 Elsevier Inc. All rights reserved.
  • Antiallodynic effect of etidronate, a bisphosphonate, in rats with adjuvant-induced arthritis: Involvement of ATP-sensitive K+ channels, Atsufumi Kawabata, Naoyuki Kawao, Yoshimi Hironaka, Tsuyoshi Ishiki, Maho Matsunami, Fumiko Sekiguchi, NEUROPHARMACOLOGY, NEUROPHARMACOLOGY, 51(2), 182 - 190, Aug. 2006 , Refereed
    Summary:Bisphosphonates, pyrophosphate analogues, known as inhibitors of bone resorption, appear to cause analgesia in certain clinical painful situations. To detect clinically relevant analgesic property of etidronate, a non-aminobisphosphonate, we examined and characterized its antiallodynic effect in the rat with adjuvant-induced arthritis, in comparison with alendronate, an aminobisphosphonate, as determined by the von Frey test. Repeated systemic administration of etidronate at 10-40 mg/kg/day suppressed the adjuvant-induced mechanical allodynia in rat hindpaw, an effect reaching a plateau in approximately 10 days. Systemic or intraplantar (i.pl.) administration of ATP-sensitive K+ (K-ATP(+)) channel inhibitors, glibenclamide and/or tolbutamide, completely reversed the antiallodynic effect of etidronate within 1 h in the arthritic rats, without affecting the nociceptive scores in naive or arthritic animals that had not received etidronate. Alendronate, administered repeatedly, also revealed similar glibenclamide-reversible antiallodynic effect. In contrast, the antiallodynic effect of repeated systemic indomethacin was resistant to i.pl. glibenclamide in the arthritic rats. Repeated administration of etidronate or alendronate only slightly attenuated the adjuvant-evoked hindpaw edema. Among K-ATP(+) channel subunits, mRNAs for Kir6.1, SUR1, SUR2A and SUR2B were abundant in rat dorsal root ganglia, while Kir6.2 mRNA was poor. Our data demonstrate that repeated etidronate as well as alendronate exhibits antiallodynic activity in arthritic rats, which might be clinically relevant, and suggest involvement of K-ATP(+) channels in the underlying mechanisms. (c) 2006 Elsevier Ltd. All rights reserved.
  • Colonic hyperalgesia triggered by proteinase-activated receptor-2 in mice: Involvement of endogenous bradykinin, A Kawabata, N Kawao, T Kitano, M Matsunami, R Satoh, T Ishiki, T Masuko, T Kanke, N Saito, NEUROSCIENCE LETTERS, NEUROSCIENCE LETTERS, 402(1-2), 167 - 172, Jul. 2006 , Refereed
    Summary:Intracolonic (i.col.) administration of the PAR2-activating peptide (PAR2AP) SLIGRL-NH2 Slowly develops visceral hypersensitivity to i.col. capsaicin in ddY mice. Thus, we further analyzed roles of PAR2 in colonic hypersensitivity, using the novel potent PAR2AP, 2-furoyl-LIGRL-NH2 and PAR2-knockout (KO) mice. In ddY mice, i.col. 2-furoyl-LIGRL-NH2 produced delayed (6 h later) facilitation of capsaicin-evoked visceral nociception, an effect,being much more potent than SLIGRL-NH2. Such effects were mimicked by i.col. trypsin. In wild-type (WT), but not PAR2-KO, mice of C57BL/6 background, i.col. PAR2 agonists caused delayed facilitation of sensitivity to capsaicin. The PAR2-triggered visceral hypersensitivity was abolished by a bradykinin B2 receptor antagonist, HOE-140. Our data thus provide ultimate evidence for role of PAR2 in colonic hypersensitivity, and suggest involvement of the bradykinin-B2 pathway. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
  • Suppression of pancreatitis-related allodynia/hyperalgesia by proteinase-activated receptor-2 in mice, A Kawabata, M Matsunami, M Tsutsumi, T Ishiki, O Fukushima, F Sekiguchi, N Kawao, T Minami, T Kanke, N Saito, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 148(1), 54 - 60, May 2006 , Refereed
    Summary:1 Proteinase-activated receptor-2 (PAR2), a receptor activated by trypsin and tryptase, is abundantly expressed in the gastrointestinal tract including the C-fiber terminal, and might play a role in processing of visceral pain. In the present study, we examined and characterized the roles of PAR2 in pancreatitis-related abdominal hyperalgesia/allodynia in mice. 2 Caerulein, administered i.p. once, caused a small increase in abdominal sensitivity to stimulation with von Frey hairs, without causing pancreatitis, in PAR2-knockout (KO) mice, but not wild-type (WT) mice. 3 Caerulein, given hourly six times in total, caused more profound abdominal hyperalgesia/allodynia in PAR2-KO mice, as compared with WT mice, although no significant differences were detected in the severity of pancreatitis between the KO and WT animals. 4 The PAR2-activating peptide, 2-furoyl-LIGRL-NH2, coadministered repeatedly with caerulein six times in total, abolished the caerulein-evoked abdominal hyperalgesia/allodynia in WT, but not PAR2-KO, mice. Repeated doses of 2-furoyl-LIGRL-NH2 moderately attenuated the severity of caerulein-induced pancreatitis in WT animals. 5 Our data from experiments using PAR2-KO mice provide evidence that PAR2 functions to attenuate pancreatitis-related abdominal hyperalgesia/allodynia without affecting pancreatitis itself, although the PAR2AP applied exogenously is not only antinociceptive but also anti-inflammatory.
  • Mechanisms for modulation of mouse gastrointestinal motility by proteinase-activated receptor (PAR)-1 and-2 in vitro, F Sekiguchi, N Hasegawa, K Inoshita, D Yonezawa, N Inoi, T Kanke, N Saito, A Kawabata, LIFE SCIENCES, LIFE SCIENCES, 78(9), 950 - 957, Jan. 2006 , Refereed
    Summary:Proteinase-activated receptor (PAR)-1 or -2 modulates gastrointestinal transit in vivo. To clarify the underlying mechanisms, we characterized contraction/relaxation caused by TFLLR-NH2 and SLIGRL-NH2, PAR-1- and -2-activating peptides, respectively, in gastric and small intestinal (duodenal, jejunal and ileal) smooth muscle isolated from wild-type and PAR-2-knockout mice. Either SLIGRL-NH2 or TFLLR-NH2 caused both relaxation and contraction in the gastrointestinal preparations from wild-type animals. Apamin, a K+ channel inhibitor, tended to enhance the peptide-evoked contraction in some of the gastrointestinal preparations, whereas it inhibited relaxation responses to either peptide completely in the stomach, but only partially in the small intestine. Indomethacin reduced the contraction caused by SLIGRL-NH2 or TFLLR-NH2 in both gastric and ileal preparations, but unaffected apamin-insensitive relaxant effect of either peptide in ileal preparations. Repeated treatment with capsaicin suppressed the contractile effect of either peptide in the stomach, but not clearly in the ileum, whereas it enhanced the apamin-insensitive relaxant effect in ileal preparations. In any gastrointestinal preparations from PAR-2-knockout mice, SLIGRL-NH2, produced no responses. Thus, the inhibitory component in tension modulation by PAR-1 and -2 involves both apamin-sensitive and -insensitive mechanisms in the small intestine, but is predominantly attributable to the former mechanism in the stomach. The excitatory component in the PAR-1 and -2 modulation may be mediated, in part, by activation of capsaicin-sensitive sensory nerves and/or endogenous prostaglandin formation. Our study thus clarifies the multiple mechanisms for gastrointestinal motility modulation by PAR-1 and -2, and also provides ultimate evidence for involvement of PAR-2. (c) 2005 Elsevier Inc. All rights reserved.
  • Physiology and pathophysiology of proteinase-activated receptors (PARs): PAR-2 as a potential therapeutic target, T Kanke, T Takizawa, M Kabeya, A Kawabata, JOURNAL OF PHARMACOLOGICAL SCIENCES, JOURNAL OF PHARMACOLOGICAL SCIENCES, 97(1), 38 - 42, Jan. 2005 , Refereed
    Summary:PAR-2 is the second member of the family of proteinase-activated receptors activated by trypsin, tryptase, and several other serine proteinases. In order to evaluate the therapeutic potential for PAR-2, we have performed studies on PAR-2-mediated signal transduction and investigated the effects of PAR-2 gene deficiency in disease models. In addition to the G-protein-coupled receptor-mediated common signal transduction pathways, inositol 1,4,5-trisphosphate production and mobilization of Ca2+, PAR-2 can also activate multiple kinase pathways, EPK, p38MAPK, JNK, and IKK, in a cell-type specific manner. The studies using PAR-2-gene-deficient mice highlighted critical roles of PAR-2 in progression of skin and joint inflammation. We also describe the development and evaluation of potent and metabolically stable PAR-2 agonists in multiple assay systems both in vitro and in vivo. The structure-activity relationship analysis indicated the improved potencies of furoylated peptides. Furthermore, the resistance of the furoylated peptide against aminopeptidase contributed to the highly potent and sustained effects of the peptide in vivo. These studies suggest the potential therapeutic importance of PAR-2 in inflammatory diseases. Also, the PAR-2-gene-deficient mice and the potent and metabolically stable agonists are shown to be useful tools for evaluating the potency of PAR-2 as a therapeutic target.
  • 2-Furoyl-LIGRL-NH2, a potent agonist for proteinase-activated receptor-2, as a gastric mucosal cytoprotective agent in mice, A Kawabata, Y Oono, D Yonezawa, K Hiramatsu, N Inoi, F Sekiguchi, M Honjo, M Hirofuchi, T Kanke, H Ishiwata, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 144(2), 212 - 219, Jan. 2005 , Refereed
    Summary:1 Proteinase-activated receptor-2 (PAR(2)), expressed in capsaicin-sensitive sensory neurons, plays a protective role in gastric mucosa. The present study evaluated gastric mucosal cytoprotective effect of 2-furoyl-LIGRL-NH2, a novel highly potent PAR(2) agonist, in ddY mice and in wild-type and PAR(2)-knockout mice of C57BL/6 background. 2 Gastric mucosal injury was created by oral administration of HCl/ethanol solution in the mice. The native PAR(2)-activating peptide SLIGRL-NH2, administered intraperitoneally (i.p.) at 0.3 - 1 mumol kg(-1) in combination with amastatin, an aminopeptidase inhibitor, but not alone, revealed gastric mucosal protection in ddY mice, which was abolished by ablation of capsaicin-sensitive sensory neurons. 3 I.p. administration of 2-furoyl-LIGRL-NH2 at 0.1 mumol kg(-1), without combined treatment with amastatin, exhibited gastric mucosal cytoprotective activity in ddY mice, the potency being much greater than SLIGRL-NH2 in combination with amastatin. This effect was also inhibited by capsaicin pretreatment. 4 Oral administration of 2-furoyl-LIGRL-NH2 at 0.003 - 0.03 mumol kg(-1) also protected against gastric mucosal lesion in a capsaicin-reversible manner in ddY mice. 5 I.p. 2-furoyl-LIGRL-NH2 at 0.1 - 0.3 mumol kg(-1) caused prompt salivation in anesthetized mice, whereas its oral administration at 0.003 - 1 mumol kg(-1) was incapable of eliciting salivation. 6 In wild-type, but not PAR(2)-knockout, mice of C57BL/6 background, i.p. administration of 2-furoyl-LIGRL-NH2 caused gastric mucosal protection. 7 Thus, 2-furoyl-LIGRL-NH2 is considered a potent and orally available gastric mucosal protective agent. Our data also substantiate a role for PAR2 in gastric mucosal protection and the selective nature of 2-furoyl-LIGRL-NH2.
  • The potent inducible nitric oxide synthase inhibitor ONO-1714 inhibits neuronal NOS and exerts antinociception in rats, F Sekiguchi, Y Mita, Y Kamanaka, N Kawao, H Matsuya, C Taga, A Kawabata, NEUROSCIENCE LETTERS, NEUROSCIENCE LETTERS, 365(2), 111 - 115, Jul. 2004 , Refereed
    Summary:We evaluated if ONO-1714, known as an inducible nitric oxide synthase (iNOS) inhibitor, could inhibit neuronal NOS (nNOS) and exert antinociception. ONO-1714 potently inhibited both crude rat cerebellar NOS and recombinant human nNOS in vitro. Systemic ONO-1714 at 1-10 mg/kg suppressed carrageenan-induced thermal hyperalgesia in rats, an effect being equivalent to the antinociception caused by L-NAME or 7-nitroindazole at 25 m/kg. The same doses of ONO-1714 also caused hypertension. Intrathecal (j.t.) ONO-1714 potently reduced the hyperalgesia. the effective dose range (0.2-0.6 mug/rat) being much lower than the antinociceptive dose (150 mug/rat) of i.t. L-NAME. Thus, ONO-1714 is considered a potent inhibitor of nNOS in addition to iNOS. The distinct relative antinociceptive activities of systemic and i.t. ONO-1714 are attributable to its possible poor blood-brain barrier permeability. (C) 2004 Elsevier Ireland Ltd. All rights reserved.
  • Role of N-methyl-D-aspartate receptors and the nitric oxide pathway in nociception/hyperalgesia elicited by protease-activated receptor-2 activation in mice and rats, A Kawabata, N Kawao, H Itoh, C Shimada, K Takebe, R Kuroda, T Masuko, K Kataoka, S Ogawa, NEUROSCIENCE LETTERS, NEUROSCIENCE LETTERS, 329(3), 349 - 353, Sep. 2002 , Refereed
    Summary:Activation of the peripheral protease-activated receptor-2 (PAR-2) triggers nociceptive behaviour and thermal hyperalgesia in rats. The present study created a novel mouse model for PAR-2-triggered nociception, and then examined the roles of NMIDA receptors and the nitric oxide (NO) pathway in nociceptive processing by PAR-2. Intraplantar administration of the PAR-2 agonist SLIGRL-NH2 elicited nociceptive responses in mice, an effect being more specific in mast cell-depleted mice. This PAR-2-triggered nociception was abolished by the NMDA receptor antagonist MK-801, but not the neuronal NO synthase inhibitor 7-nitro indazole. In contrast, the PAR-2-triggered thermal hyperalgesia in rats was blocked by both agents. Our study thus provides a novel mouse model for PAR-2-mediated nociception, and suggests that NMDA receptors are involved in PAR-2-triggered nociception and hyperalgesia, while NO contributes only to the latter. (C) 2002 Published by Elsevier Science Ireland Ltd.
  • Capsazepine partially inhibits neurally mediated gastric mucus secretion following activation of protease-activated receptor 2, A Kawabata, M Kinoshita, R Kuroda, K Kakehi, CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, 29(4), 360 - 361, Apr. 2002 , Refereed
    Summary:1. Protease-activated receptor 2 (PAR2), present in capsaicin-sensitive sensory neurons, induces gastric mucus secretion and mucosal cytoprotection. 2. We studied the possible cross-talk between PAR2 and vanilloid receptor 1 (VR1). The VR1 antagonist capsazepine partially inhibited the PAR2-mediated increase in gastric mucus secretion. 3. Thus, activation of VR1 is responsible, at least in part, for the neurally mediated mucosal cytoprotection following activation of PAR2.
  • Protease-activated receptor-2 (PAR-2) in the rat gastric mucosa: immunolocalization and facilitation of pepsin/pepsinogen secretion, N Kawao, Y Sakaguchi, A Tagome, R Kuroda, S Nishida, K Irimajiri, H Nishikawa, K Kawai, MD Hollenberg, A Kawabata, BRITISH JOURNAL OF PHARMACOLOGY, BRITISH JOURNAL OF PHARMACOLOGY, 135(5), 1292 - 1296, Mar. 2002 , Refereed
    Summary:1 Agonists of protease-activated receptor-2 (PAR-2) trigger neurally mediated mucus secretion accompanied by mucosal cytoprotection in the stomach. The present study immunolocalized PAR-2 in the rat gastric mucosa and examined if PAR-2 could modulate pepsin/pepsinogen secretion in rats. 2 PAR-2-like immunoreactivity was abundant in the deep regions of gastric mucosa, especially in chief cells. 3 The PAR-2 agonist SLIGRL-NH2, but not the control peptide LSIGRL-NH2 adininistered i.v. repeatedly at 0.3-1 mumol kg(-1), four times in total, significantly facilitated gastric pepsin secretion, although a single dose produced no significant effect. 4 The PAR-2-mediated gastric pepsin secretion was resistant to omeprazole, N-G-nitro-L-arginine methyl ester (L-NAME) or atropine, and also to ablation of sensory neurons by capsaicin. 5 Our study thus provides novel evidence that PAR-2 is localized in mucosal chief cells and facilitates gastric pepsin secretion in the rats. most probably by a direct mechanism. British Journal of Pharmacology (2002).
  • Specific expression of spinal Fos after PAR-2 stimulation in mast cell-depleted rats, A Kawabata, N Kawao, R Kuroda, H Itoh, H Nishikawa, NEUROREPORT, NEUROREPORT, 13(4), 511 - 514, Mar. 2002 , Refereed
    Summary:Protease-activated receptor-2 (PAR-2) in the sensory neurons may be involved in nociceptive processing. We attempted to detect and characterize specific expression of spinal Fos, a marker of nociception, in mast cell-depleted rats. Intraplantar (i.pl) administration of not only the PAR-2 agonist SLIGRL-NH2, but also the control peptide LSIGRL-NH2, induced Fos expression in naive rats, whereas only the former specifically produced Fos expression in mast cell-depleted rats. This Fos expression was blocked by intrathecal DAMG0, a mu-opioid agonist, and, in part, by i.pl. calphostin C, a protein kinase C (PKC) inhibitor. Thus, specific expression of spinal Fos following peripheral PAR-2 activation is detectable in mast cell-depleted rats, suggesting activation of spinal nociceptive neurons, which is partially mediated by activation of PKC.

Books etc

  • H2S and pain: a novel aspect for processing of somatic, visceral and neuropathic pain signals. In Chemistry, Biochemistry and Pharmacology of Hydrogen Sulfide, edited by Moore, P.K. and Whiteman, M., Terada, Y, Kawabata, A, Joint author, Springer,   2015
  • Disseminated intravascular coagulation (DIC)-like events produced by environmental stress and by lipopolysaccharide : Nitric oxide as a common key molecule., The Biology of Nitric Oxide Part 6(Portland Press, London),   1998
  • Multiplicity of the role of nitric oxide in pain modulation,   1996
  • NO and Pain(共著), NO,   1995
  • The Role of NO in Pain Processing(共著), Nitric Oxide (Experimental Medicine),   1995
  • The dual role of L-arginine in nociceptive processing in the brain : involvement of nitric oxide and kyotorphin(共著), Nitric Oxide-Roles in Neuronal Communication and Neurotoxicity (Japan Scientific Societies Press, and CRC Press),   1994

Conference Activities & Talks

  • Azelastine attenuates RAGE-dependent allodynia in mice: a discovery by a drug reprofiling/repositioning approach., Wakitani, K, Sekiguchi, F, Tsubota, M, Nakamura, S, Nakanishi, I, Kawabata, A, 17th World Congress on Pain.,   2018 09 12
  • Pharmacological blockade and genetic deletion of Cav3.2 T-type Ca2+ channels abolish butyrate-induced colonic hypersensitivity in mice., Matsui, K, Nakano, M, Tomochika, K, Tsubota, M, Kawabata, A, 17th World Congress on Pain.,   2018 09 12
  • Middle Molecular Weight Heparinylphenylalanine Prevents the Development of Chemotherapy-Induced Peripheral Neuropathy in Mice., Kawabata, A, Nishikawa, H, Uenoyama, K, Sekiguchi, F, Tsubota, M, Okada, T, Toyooka, N, 17th World Congress on Pain.,   2018 09 12
  • Effect of extracellular HMGB1 on neuritogenesis in mouse dorsal root ganglion neurons and its inhibition by thrombomodulin alfa., Nakatake, Y, Sekiguchi, F, Tsubota, M, Tsujita, R, Honda, G, Kawabata, A, 11thFENS Forum of Neuroscience.,   2018 07 07
  • ATP and HMGB1 mediate H2S-dependent bladder pain in mice with cyclophosphamide-induced cystitis., Hiramoto, S, Tsubota, M, Yamaguchi, K, Toriyama, Y, Tanaka, J, Sekiguchi, F, Ishikura, H, Nishibori, M, Kawabata, A, 11thFENS Forum of Neuroscience.,   2018 07 07
  • Molecular mechanisms for the HMGB1-dependent mechanical allodynia following intraplantar administration of lipopolysaccharidein mice., Domoto, R, Yamasoba, D, Sekiguchi, F, Tsubota, M, Nishibori, M, Kawabata, A, 11thFENS Forum of Neuroscience.,   2018 07 07
  • A. Agonistic activity of 6-prenylnaringenin, a novel T-type Ca2+ channel inhibitor, toward cannabinoid CB1 receptors in neural progenitor-like NG108-15 cells and CB1-transfected HEK293 cells., Sekiguchi, F, Noda, S, Kasanami, Y, Onishi, R, Ono, S, Murata, K, Matsuda, H, Nguyen, H.D, Toyooka, N, Harada, N, Kawabata, A, 11thFENS Forum of Neuroscience.,   2018 07 07
  • Cav3.2 T-type calcium channels as therapeutic targets for bortezomib-induced peripheral neuropathy in mice., Kawabata, A, Tomita, S, Miyazaki, T, Deguchi, T, Sekiguchi, F, Tsubota, M, Nguyen, H.D, Okada, T, Yoshida, S, Toyooka, N, 11thFENS Forum of Neuroscience.,   2018 07 07
  • Molecular mechanisms for the recombinant soluble thrombomodulin-induced suppression of HMGB1-dependent allodynia in mice: Roles of the N-terminal domains of thrombomodulin., Hayashi, Y, Tsubota, M, Tsujita, R, Honda, G, Kawabata, A, 18th World Congress of Basic and Clinical Pharmacology,   2018 07 01
  • Macrophage-derived HMGB1 is a key molecule in paclitaxel-induced peripheral neuropathy in mice: involvement of ROS generation and NF-κB activation., Domoto, R, Yamasoba, D, Yamanishi, H, Sekiguchi, F, Tsubota, M, Nishibori, M, Kawabata, A, 18th World Congress of Basic and Clinical Pharmacology,   2018 07 01
  • Middle molecular weight heparinylphenylalanine is an analgesic with reduced risk of hemorrhage., Nishikawa, H, Uenoyama, K, Sekiguchi, F, Tsubota, M, Kawabata, A, 18th World Congress of Basic and Clinical Pharmacology,   2018 07 01
  • High mobility group box 1 suppresses smooth muscle tension in rat aorta via Toll-like receptor 4-dependent upregulation of iNOS., Sekiguchi, F, Yagura, A, Kawabata, A, 18th World Congress of Basic and Clinical Pharmacology,   2018 07 01
  • Role of Cav3.2 T-type calcium channels in the butyrate-induced colonic hypersensitivity in the mouse, a model for irritable bowel syndrome, Tsubota, M, Matsui, K, Nakano, M. Tomochika, K, Sekiguchi, F, Kawabata, A, 10th International Symposium on Cell/Tissue Injury and Cytoprotection/Organoprotection.,   2018 06 28
  • HMGB1 による痛みの増強に対するヒト型可溶性トロンボモジュリンの抑制作用に関与する分子メカニズム, 辻田隆一, 坪田真帆, 林佑亮, 佐伯晴香, 本田剛一, 川畑篤史, 第40回日本神経科学大会,   2017 12 14
  • Involvement of HMGB1 in postoperative pain., Kawabata, Y, Tsubota, M, Tsujita, R, Nishibori, M, Kawabata, A, Neuroscience 2017,   2017 11 11
  • Thrombin-dependent inhibition of HMGB1-induced mechanical allodynia by thrombomodulin in mice., Hayashi, Y, Tsubota, M, Tsujita, R, Honda, G, Kawabata, A, Neuroscience 2017,   2017 11 11
  • HMGB1-induced neurite outgrowth in mouse dorsal root ganglion neurons and its inhibition by thrombomodulin, Nakatake, Y, Sekiguchi, F, Tsubota, M, Tsujita, R, Honda, G, Kawabata, A, Neuroscience 2017,   2017 11 11
  • Macrophages and NF-κB signaling mediate peripheral HMGB1-induced mechanical allodynia in mice., Domoto, R, Nakashima, K, Tsubota, M, Sekiguchi, F, Kawabata, A, Neuroscience 2017,   2017 11 11
  • Tacrolimus, a calcineurin inhibitor, promotes capsaicin-induced colonic pain in mice, Matsui, K, Terada, Y, Tsubota, M, Kawabata, A, Neuroscience 2017,   2017 11 11
  • Involvement of Cav3.2 T-type calcium channels in zinc deficiency-induced mechanical allodynia in mice., Sekiguchi, F, Tomita, S, Shikimi, S, Tsubota, M, Kawabata, A, Neuroscience 2017,   2017 11 11
  • The critical role of Cav3.2 T-type calcium channels in the peripheral neuropathy induced by bortezomib, a proteasome-inhibiting chemotherapy agent, in mice., Kawabata, A, Tomita, S, Deguchi, T, Sekiguchi, F, Tsubota, M, Yoshida, S, Neuroscience 2017,   2017 11 11
  • HMGB1 and pain., Kawabata, A, 第40回日本神経科学大会,   2017 07 20
  • A role of macrophage-derived HMGB1 in paclitaxel-induced peripheral neuropathy in mice., Domoto, R, Yamasoba, D, Yamanishi, H, Sekiguchi, F, Tsubota, M, Nishibori, M, Kawabata, A,   2016 10 27
  • Interleukin-6-induced neuroendocrine-like differentiation of human prostate cancer cells: cell signaling and upregulation of Cav3.2 T-type calcium channels., Fukami, K, Ueda, M, Asano, E, Sekiguchi, F, Yoshida, S, Kawabata, A,   2016 10 27
  • Cav3.2 T-type calcium channels as therapeutic targets for the oxaliplatin-induced peripheral neuropathy., Miyazaki, T, Fukuda, R, Tsubota, M, Kawabata, A,   2016 10 27
  • Molecular mechanisms for the upregulation of Cav3.2 T-type calcium channels in the neuropathic pain., Tomita, S, Sekiguchi, F, Tsubota, M, Kawabata, A,   2016 10 27
  • Targeting HMGB1 and its downstream molecules for treatment of oxaliplatin-induced peripheral neuropathy., Tsubota, M, Fukuda, R, Miyazaki, T, Domoto, R, Kamitani, N, Nishida, T, Sekiguchi, F, Ishikura, H, Nishibori, M, Kawabata, A,   2016 10 27
  • Mechanisms of Cav3.2 upregulation in neuropathic pain models., Tomita, S,   2016 10 02
  • Involvement of Cav3.2 T-type Ca2+channels in the oxaliplatin-induced neuropathic pain., Tsubota, M,   2016 10 02
  • Impact of zinc or ascorbic acid deficiency on Cav3.2-dependent pain., Kawabata, A,   2016 10 02
  • Macrophage-derived HMGB1 participates in lipopolysaccharide-induced inflammatory hyperalgesia and paclitaxel-induced neuropathic pain in mice., Domoto, R, Yamasoba, D, Yamanishi, H, Sekiguchi, F, Tsubota, M, Nishibori, M, Kawabata, A,   2016 09 26
  • Cav3.2 T-type calcium channels contribute to oxaliplatin-induced neuropathic pain in mice., Miyazaki, T, Fukuda, R, Tsubota, M, Kawabata, A,   2016 09 26
  • Tacrolimus causes relapse of pancreatic pain through TRPV1 activation during the recovery from cerulein-induced pancreatitis in mice., Terada, Y, Tsubota, M, Sekiguchi, F, Wada, K, Kuwahara, T, Takada, M, Kawabata, A,   2016 09 26
  • Roles of TLR4 and RAGE targeted by high mobility group box 1 in inflammatory and chemotherapy-induced peripheral neuropathy., Kawabata, A,   2016 09 26
  • High mobility group box 1 mediates substance P-induced bladder pain in mice, a model for bladder pain syndrome., Maeda, M, Irie, Y, Tsubota, M, Kubo, L, Sekiguchi, F, Ishikura, H, Nishibori, M, Kawabata, A,   2016 07 28
  • Macrophage-derived high mobility group box 1 mediates H2S-dependent bladder pain in mice with cyclophosphamide-induced cystitis., Hiramoto, S, Tsubota, M, Yamguchi, K, Tanaka, J, Sekiguchi, F, Ishikura, H, Nishibori, M, Kawabata, A,   2016 07 28
  • Involvement of macrophage-derived high mobility group box 1 in paclitaxel-induced neuropathic pain in mice., Domoto, R, Yamasoba, D, Yamanishi, H, Sekiguchi, F, Tsubota, M, Nishibori, M, Kawabata, A,   2016 07 28
  • Macrophage-derived high mobility group box 1 enhances neuritogenesis via NMDA receptors in neuron-like NG108-15 cells., Sekiguchi, F, Sugimoto, R, Imanishi, M, Ueda, N, Kawabata, A,   2016 07 28
  • High mobility group box 1 mediates pancreatic pain in mice., Kawabata, A, Irie, Y, Tsubota, M, Sekiguchi, F, Ishikura, H, Nishibori, M,   2016 07 28
  • T-type calcium channels and neuropathic/visceral pain. Symposium entitled “Ion channels and pain: current research trends” organized by Kawabata, Tanabe and Zamponi,, Kawabata, A, 日本薬学会第136年会,   2016 03 27
  • Molecular mechanisms for the upregulation of Cav3.2 T-type calcium channels in the dorsal root ganglion of rats with spinal nerve injury-induced neuropathy: involvement of Egr-1 and USP5., Tomita, S, Sekiguchi, F, Tsubota, M, Kawabata, A, Neuroscience 2015,   2015 10 17
  • The electrophysiological property and antihyperalgesic activity of sophoraflavanone G and 6prenylnaringenin, novel T-type calcium channel blockers., Ono, S, Ichii, M, Yamaoka, S, Sekiguchi, F, Fujita, T, Deguchi, T, Tsubota, M, Nishikawa, H, Yoshida, S, Murata, K, Matsuda, H, Toyooka, N, Ohkubo, T, Kawabata, A, Neuroscience 2015,   2015 10 17
  • Chronic stress enhances the hyperthermia in response to acute restraint stress., Miyamato, T, Funakami, Y, Kawasita, E, Nomura, A, Sugimoto, N, Ichida, S, Kawabata, A, Neuroscience 2015,   2015 10 17
  • Zinc deficiency aggravates bladder pain accompanying cyclophosphamide-induced cystitis through the enhanced activity of Cav3.2 T-type Ca2+ channels in mice., Ozaki, T, Matsuoka, J, Tsubota, M, Tomita, S, Sekiguchi, F, Minami, T, Kawabata, A, Neuroscience 2015,   2015 10 17
  • Macrophage-derived high mobility group box 1 participates in the development and maintenance of pancreatic pain through the activation of RAGE and CXCR4 in mice with cerulein-induced acute pancreatitis., Irie, Y, Tsubota, M, Sekiguchi, F, Ishikura, H, Nishibori, M, Kawabata, A, Neuroscience 2015,   2015 10 17
  • Hydrogen sulfide and intracellular cyclic AMP enhance T-type calcium channel-dependent neurite outgrowth in distinct subpopulations of isolated and dissociated mouse dorsal root ganglion neurons., Sekiguchi, F, Amo, I, Ono, S, Kawabata, A, Neuroscience 2015,   2015 10 17
  • Bladder pain accompanying cyclophosphamide-induced mouse cystitis involves HMGB1 release upstream of the cystathionine-gamma-lyase/H2S/Cav3.2 pathway in the bladder tissue., Kawabata, A, Tsubota, M, Yamaguchi, K, Hiramoto, S, Sekiguchi, F, Tanaka, J, Ishikura, H, Nishibori, M, Neuroscience 2015,   2015 10 17
  • Vitamin C deficiency aggravates hydrogen sulfide-induced pain/hyperalgesia and chemotherapy-induced neuropathy in mice: possible involvement of T-type calcium channels., Kawabata, A, Tsubota, M, Uebo, K, Miki, K, Sekiguchi, F, Fukuda, R, Kondo, Y, Takahashi, K, Masutomi, H, Ishigami, A,   2015 09 02
  • Involvement of high mobility group box 1 in substance P-induced cystitis-related bladder pain in mice, Irie, Y, Kubo, L, Tsubota, M, Sekiguchi, F, Ishimura, H, Nishibori, M, Kawabata, A, Pharmacology 2014,   2014 12 16
  • The novel cognitive enhancer ST101 induces neurite outgrowth in NG108-15 cells and hyperalgesia in mice through T-type Ca2+ channels, Ohno, S, Kanaoka, D, Ide, H, Sekiguchi, F, Yoshida, S, Fukunaga, K, Kawabata, A, Pharmacology 2014,   2014 12 16
  • The NK1 receptor antagonist prevents the cyclophosphamide-induced cystitis-related bladder pain and upregulation of cystathionine-γ-lyase, an H2S-generating enzyme, in mice, Ozaki, T, Tsubota, M, Kawabata, A, Pharmacology 2014,   2014 12 16
  • Effect of tacrolimus on caerulein-induced pancreatitis-related pain in mice, Terada, Y, Tsubota, M, Sekiguchi, F, Wada, K, Kuwahara, T, Takada, M, Kawabata, K, Pharmacology 2014,   2014 12 16
  • High mobility group box 1 as a target for prevention and therapeutic treatment of chemotherapy-induced neuropathic pain., Kawabata, A, Kawaishi, Y, Nishida, T, Yamanishi, H, Kamitani, N, Tsubota, M, Sekiguchi, F, Ishikura, H, Nishibori, M, Pharmacology 2014,   2014 12 16
  • Mechanims for upregulation of cystathionine-gamma-lyase, a hydrogen sulfide-generating enzyme, in mice with cyclophosphamide-induced cystititis: Involvement of substance P/NK1 pathway and NF-kappaB signals., Ozaki, T, Tsubota, M, Kawabata, A, International Symposium “Gasotransmitters: Physiology and Pathophysiology”,   2014 09 21
  • Hydrogen sulfide: Importance of T-type calcium channels as the molecular target, Kawabata, A, International Symposium “Gasotransmitters: Physiology and Pathophysiology”,   2014 09 21
  • Exploration of novel T-type Ca2+ channel inhibitors for treatment of intractable pain, Sekiguchi, F, Kawabata, A, 生体機能と創薬シンポジウム2014,   2014 08 28
  • Sophoraflavanone G as a novel T-type Ca2+ channel inhibitor: electrophysiological evidence in Cav3.2-expressing HEK293 cells and anti-hyperalgesic activity in mice, Sekiguchi, F, Fujita, T, Deguchi, T, Ichii, M, Yamaoka, S, Nishikawa, H, Yoshida, S, Murata, K, Matsuda, M, Ohkubo, T, Kawabata, A, 9th FENS Forum of European Neuroscience,   2014 07 05
  • Prevention and reversal of chemotherapy-induced neuropathic pain by HMGB1 neutralization in rodents, Kawabata, A, Kawaishi, Y, Nishida, T, Yamanishi, H, Kamitani, N, Tsubota, M, Ishikura, H, Sekiguchi, F, Nishibori, M, 9th FENS Forum of European Neuroscience,   2014 07 05
  • Roles of hydrogen sulfide and T-type calcium channels in neuroendocrine-differentiated prostate cancer cells at androgen-independent stage, Fukami, K, Kawabata, A, Anti-Aging International Mini-Symposium 2014: Cell Signaling and Therapeutic Targets for Geriatric and Inflammatory Diseases,   2014 06 07
  • Ascorbic acid deficiency augments hyperalgesia induced by hydrogen sulfide in mice, Tsubota, M, Uebo, K, Miki, K, Sekiguchi, F, Kondo, Y, Takahashi, K, Masutomi, H, Ishigami, A, Kawabata, A, Third International Conference on Hydrogen Sulfide in Biology and Medicine,   2014 06 04
  • Involvement of endogenous hydrogen sulfide and T-type calcium channels in cyclic AMP-induced neuronal differentiation in NG108-15 cells, Sekiguchi, F, Takeda, Y, Kanaoka, D, Yoshida, S, Kawabata, A, Third International Conference on Hydrogen Sulfide in Biology and Medicine,   2014 06 04
  • Roles of the hydrogen sulfide-Cav3.2 T-type calcium channel pathway in neuronal and neuroendocrine differentiation, Kawabata, A, Third International Conference on Hydrogen Sulfide in Biology and Medicine,   2014 06 04
  • Roles of Cav3.2 T-type Ca2+ channels in prostate cancer cells: impact on an androgen-independent stage, Kawabata, A, 第87回日本薬理学会年会,   2014 03 19
  • Involvement of high mobility group box 1 in cyclophosphamide-induced cystitis-related bladder pain in mice., Kawabata, A, Tanaka, J, Yamaguchi, K, Ishikura, H, Tsubota, M, Pharmacology 2013,   2013 12 17
  • Recombinant human soluble thrombomodulin abolishes bladder pain accompanying cyclophosphamide-induced cystitis in mice, Tanaka, J, Ishikura, H, Yamaguchi, K, Tsubota, M, Sekiguchi, F, Seki, Y, Kawabata, A, Neuroscience 2013,   2013 11
  • Roles of TRPA1 channels in addition to Cav3.2 or TRPV1 as the downstream signal of hydrogen sulfide or proteinase-activated receptor-2 in the development of pancreatic pain, Terada, Y, Fujimura, M, Nishimukra, S, Tsubota, M, Kawabata, A, Neuroscience 2013,   2013 11
  • RQ-00311651, a novel T-type Ca2+ channel blocker: electrophysiological characterization and anti-hyperalgesic/anti-allodynic activity in somatic and visceral pain models., Sekiguchi, F, Kawara, Y, Kanaoka, D, Kawaishi, Y, Tsubota, M, Kawakami, E, Ozaki, T, Yoshida, S, Okubo, T, Kawabata, A, Neuroscience 2013,   2013 11
  • Facilitation of T-type calcium currents by endogenous and exogenous hydrogen sulfide in Cav3.2-expressing HEK293 cells, Kawabata, A, Miyamoto, Y, Sekiguchi, F, Kanaoka, D, Yoshida, S, Ohkubo, T, Neuroscience 2013,   2013 11
  • Modulation of Cav3.2 T-type calcium channels by endogenous mediators: impact on pain signals and others, Kawabata, A, 3rd International Calcium Channel Conference,   2013 03 24
  • Roles of endogenous hydrogen sulfide in the cyclic AMP-induced neuronal differentiation in NG108-15 cells, Kanaoka, D, Takeda, Y, Sekiguchi, F, Yoshida, S, Kawabata, A, Neuroscience 2012,   2012 10 13
  • Molecular mechanisms for the neurite outgrowth caused by prostaglandin E2 in mouse dorsal root ganglion cells, Maeda, T, Mitani, K, Yamagata, R, Sekiguchi, F, Kawabata, A, Neuroscience 2012,   2012 10 13
  • Recombinant soluble human thrombomodulin abolishes inflammatory hyperalgesia in rats, Tanaka, J, Seki, Y, Yamaguchi, K, Ishikura, H, Tsubota, M, Sekiguchi, F, Kawabata, A, Neuroscience 2012,   2012 10 13
  • Blocking T-type calcium channels protects against the brain injury induced by middle cerebral artery occlusion and reperfusion in mice, Kawabata, A, Nishikawa, H, Matsuda, S, Fukatsu, A, Kurokawa, Y, Tsubota-Matsunami, M, Tokuyama, S, Neuroscience 2012,   2012 10 13
  • Roles of endogenous hydrogen sulfide in proliferation of gastric cancer cells., Sekiguchi, F, Sekimoto, T, Ogura, A, Kawabata, A,   2012 09 09
  • Roles of Cav3.2 and TRPA1 channels targeted by hydrogen sulfide in processing of visceral pain signals in the colon, pancreas and bladder, Kawabata, A, 7th International Symposium on Cell/Tissue Injury and Cyotoprotection/Organoprotection,   2012 09 09

Misc

  • 内臓痛におけるマクロファージ由来HMGB1の役割と治療標的分子としての可能, 坪田 真帆, 川畑 篤史, PAIN RESEARCH, 34, 1, 24, 30,   2019 03
    Summary:これまでの研究により、マクロファージ由来核内蛋白high mobility group box1(HMGB1)は多様な内臓痛の発症に関与する他、癌化学療法の副作用として生じる有痛性末梢神経障害の発症に重要な役割を果たすことが明らかになっている。すなわち、HMGB1は免疫細胞と神経細胞のクロストークを媒介する分子として、難治性疼痛の発症に深く関わっていると思われる。膀胱、膵臓、大腸などにおける内臓痛へのHMGB1の関与に焦点を絞り概説した。
  • 散薬および溶解液の状態から気化するイホスファミド量の調査(Investigation of the Levels of Ifosfamide Vaporized from Powder and Solution), 小泉 祐一, 石渡 俊二, 井上 知美, 高田 充隆, 川畑 篤史, 小竹 武, 日本職業・災害医学会会誌, 67, 2, 95, 99,   2019 03
    Summary:背景:抗腫瘍薬にはがん治療において重要な役割がある一方、医療従事者に対しては有害である可能性がある。イホスファミドとシクロホスファミドは、危険性医薬品に分類される。これらの薬剤は揮発し、吸入することで体内に入る可能性がある。しかし、イホスファミドの揮発に関する報告がほとんどない。目的:本研究の目的は、溶解液または散薬の状態から揮発した後、空気中のイホスファミドの濃度を調査することである。方法:室温付近において、溶解液または散薬の状態から揮発したイホスファミドをLC-MS/MSによって、空気中の濃度を定量する。結果:25℃と40℃の溶液からの空気中のイホスファミドの濃度はそれぞれ3.1pg/Lと293pg/Lであった。この2つの温度の濃度には100倍の差がみられた。これと同様に、散薬からの揮発においてもイホスファミドの濃度は、増加した。対応する温度において、イホスファミドの空気中濃度は、溶液と比較すると散薬からの揮発において1〜2桁、低い値となった。結論:我々の結果は、高温においてイホスファミドに曝露のリスクを明示した。イホスファミド製剤を調製するときには、温度と薬剤の状態について特別な注意を払う必要がある。(著者抄録)
  • 細胞外ATPによって惹起された外有毛細胞の硫化水素産生, 原田 成信, 伊藤 由香里, 王子田 彰夫, 川畑 篤史, Otology Japan, 28, 4, 359, 359,   2018 09
  • 活性硫黄種の新展開-硫化水素から過硫化物まで- 内臓痛発現における硫化水素および過硫化物の役割, 坪田 真帆, 川畑 篤史, 日本生化学会大会プログラム・講演要旨集, 91回, [1S06p, 04],   2018 09
  • 内臓痛の分子メカニズム-特に神経系と免疫系のクロストークについて 内臓痛におけるマクロファージ由来HMGB1の役割と治療標的分子としての可能性, 川畑 篤史, PAIN RESEARCH, 33, 2, 103, 103,   2018 06
  • 急性および慢性術後痛におけるHMGB1の役割, 川端 柚希, 林 愛理沙, 坪田 真帆, 中武 ゆい, 辻田 隆一, 関口 富美子, 西堀 正洋, 川畑 篤史, PAIN RESEARCH, 33, 2, 139, 139,   2018 06
  • 中分子ヘパリニルフェニルアラニンは化学療法誘起末梢神経障害を抑制する, 西川 裕之, 上野山 桐子, 関口 富美子, 坪田 真帆, 岡田 卓哉, 豊岡 尚樹, 川畑 篤史, PAIN RESEARCH, 33, 2, 156, 156,   2018 06
  • RAGEを標的とした化学療法誘起末梢神経障害治療薬の探索 in silicoドラッグ・リプロファイリング/リポジショニングからのアプローチ, 脇谷 航平, 関口 富美子, 坪田 真帆, 中村 真也, 仲西 功, 川畑 篤史, PAIN RESEARCH, 33, 2, 157, 157,   2018 06
  • Butyrate誘起過敏性腸症候群モデルマウスの知覚神経過敏におけるCav3.2T型Ca2+チャネルの役割, 坪田 真帆, 川畑 篤史, 潰瘍, 45, 117, 117,   2018 05
  • 神経障害の病態と治療 痛みを科学する 慢性疼痛におけるCav3.2T型カルシウムチャネルの役割と治療標的分子としての可能性, 川畑 篤史, 糖尿病, 61, Suppl.1, S, 74,   2018 04
  • AzelastineはRAGEが関与する化学療法誘起末梢神経障害の発症を抑制する―ドラッグ・リプロファイリング/リポジショニング研究からの知見, 脇谷航平, 関口富美子, 坪田真帆, 中村真也, 仲西功, 川畑篤史, 日本薬理学会近畿部会プログラム・要旨集, 133rd, 44,   2018 , http://jglobal.jst.go.jp/public/201802250128640323
  • T型Ca2+チャネル阻害活性を有するホップ成分6‐prenylnaringeninは結腸痛を抑制する, 坪田真帆, 松井和樹, 中野真希, 友近拳, 関口富美子, 川畑篤史, 日本薬理学会近畿部会プログラム・要旨集, 133rd, 34,   2018 , http://jglobal.jst.go.jp/public/201802257910940137
  • がん化学療法誘起末梢神経障害モデルマウスにおける中分子ヘパリニルフェニルアラニンの抗アロディニア作用, 西川裕之, 西川裕之, 上野山桐子, 関口富美子, 坪田真帆, 岡田卓哉, 豊岡尚樹, 豊岡尚樹, 川畑篤史, 日本薬理学会近畿部会プログラム・要旨集, 133rd, 33,   2018 , http://jglobal.jst.go.jp/public/201802264948184448
  • Butyrate誘起過敏性腸症候群モデルマウスの知覚神経過敏におけるCa v3.2 T型Ca2+チャネルの役割, 坪田真帆, 川畑篤史, 日本潰瘍学会プログラム・抄録集, 45th, 101,   2017 10 20 , http://jglobal.jst.go.jp/public/201802233395721741
  • マウスにおいてHMGB1足底内投与により誘起される機械的アロディニアにはNF‐κBシグナルとマクロファージが関与する, 堂本莉紗, 中島夏奈, 関口富美子, 坪田真帆, 川畑篤史, 次世代を担う創薬・医療薬理シンポジウムプログラム・要旨集, 2017, 57,   2017 08 25 , http://jglobal.jst.go.jp/public/201702234832286886
  • Butyrate誘起過敏性腸症候群モデルマウスにおける結腸痛へのマクロファージ由来HMGB1の関与, 坪田真帆, 梶谷梨絵, 野中結, 石井優子, 関口富美子, 西堀正洋, 川畑篤史, 次世代を担う創薬・医療薬理シンポジウムプログラム・要旨集, 2017, 46,   2017 08 25 , http://jglobal.jst.go.jp/public/201702242670072548
  • Bortezomib誘起神経障害性疼痛へのマクロファージ由来HMGB1の関与, 宮崎貴也, 坪田真帆, 冨田詩織, 出口智代, 関口富美子, 西堀正洋, 川畑篤史, 次世代を担う創薬・医療薬理シンポジウムプログラム・要旨集, 2017, 63,   2017 08 25 , http://jglobal.jst.go.jp/public/201702278169871275
  • オキサリプラチン誘起神経障害性疼痛の発症メカニズムの解析:Cav3.2 T型カルシウムチャネルとHMGB1の関与, 坪田真帆, 福田亮太郎, 関口富美子, 宮崎貴也, 堂本莉紗, 安井洋樹, 山下莉加, 上田慎, 西田武司, 西田武司, 石倉宏恭, 西堀正洋, 川畑篤史, Pain Research, 32, 2, 131,   2017 06 16 , http://jglobal.jst.go.jp/public/201702276801996364
  • トロンボモジュリンアルファはトロンビン依存性にHMGB1誘起痛覚過敏を抑制する, 辻田隆一, 辻田隆一, 林佑亮, 坪田真帆, 本田剛一, 川畑篤史, Pain Research, 32, 2, 154,   2017 06 16 , http://jglobal.jst.go.jp/public/201702278643432421
  • プロテアソーム阻害薬bortezomib誘起神経障害性疼痛には一次知覚神経のCav3.2T型カルシウムチャネルタンパク量増加が関与する, 関口富美子, 冨田詩織, 出口智代, 坪田真帆, 吉田繁, 川畑篤史, Pain Research, 32, 2, 154,   2017 06 16 , http://jglobal.jst.go.jp/public/201702286774040419
  • H2S and pain, Atsufumi Kawabata, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, 127, 0, 93, 97,   2007 , http://ci.nii.ac.jp/naid/40015637284
    Summary:Like nitric oxide and carbon monoxide, hydrogen sulfide (H2S) is now considered a novel gasotransmitter, playing extensive roles throughout the mammalian body including the CNS. H2S appears to have multiple target molecules including ATP-sensitive K+ channels and N-methyl-D-aspartate (NMDA) receptors. Our recent electrophysiological study has provided evidence that T-type Ca2+ channels are novel targets for H2S in neuronal cells. H2S sensitizes T-type Ca2+ channels most probably through redox modulation. Interestingly, intraplantar administration of H2S donor causes hyperalgesia in rats, an effect being blocked by mibefradil, an inhibitor of T-type Ca2+ channels. Inhibitors of an H2S-forming enzyme attenuate the inflammatory hyperalgesia induced by intraplantar administration of lipopolysaccharide. Roles for H2S in processing of visceral nociception are a little complex. H2S might play opposing roles in distinct models for visceral pain, being pro- and anti-nociceptive. Together, H2S could be a novel gasotransmitter for processing of somatic and visceral pain.
  • Distinct roles for protease-activated receptors 1 and 2 in vasomotor modulation in rat superior mesenteric artery, KAWABATA A, KUBO S, NAKAYA Y, ISHIKI T, KURODA R, SEKIGUCHI F, KAWAO N, NISHIKAWA H, Cardiovasc. Res., 12, 4, 41, 57,   2004 03 05 , 10.1016/j.cardiores.2003.11.030, http://ci.nii.ac.jp/naid/110001179745
  • Pain Information Pathways from the Periphery to the Cerebral Cortex, KURODA Ryotaro, KAWABATA Atsufumi, YAKUGAKU ZASSHI, 123, 7, 533, 546,   2003 07 01 , 10.1248/yakushi.123.533, http://ci.nii.ac.jp/naid/110003614901
    Summary:A recent PET study revealed that the first and second somatosensory cortices (SI, SII), and the anterior cingulate cortex are activated by painful peripheral stimulation in humans. It has become clear that painful signals (nociceptive information) evoked at the periphery are transmitted via various circuits to the multiple cerebral cortices where pain signals are processed and perceived. Human or clinical pain is not merely a modality of somatic sensation, but associated with the affect that accompanies sensation. Consequently, pain has a somatosensory&ndash;discriminative aspect and an affective&ndash;cognitive aspect that are processed in different but correlated brain structures in the ascending circuits. Considering the physiologic characteristics and fiber connections, the SI and SII cortices appear to be involved in somatosensory&ndash;discriminative pain, and the anterior cingulate cortex (area 24) in the affective&ndash;cognitive aspect of pain. This paper deals with the ascending pain pathways from the periphery to these cortices and their interconnections. Our recent findings on the protease&ndash;activated receptors 1 and 2 (PAR&ndash;1, and &ndash;2), which are confirmed to exist in the dorsal root ganglion cells, are also described. Activation of PAR&ndash;2 during inflammation or tissue injury at the periphery is pronociceptive, while PAR&ndash;1 appears to be antinociceptive. Based on these findings, PAR&ndash;1 and PAR&ndash;2 are attracting interest as target molecules for new drug development.<br>
  • Physiological functions of protease-activated receptor-2, KAWABATA Atsufumi, Folia Pharmacologica Japonica, 121, 6, 411, 420,   2003 06 01 , 10.1254/fpj.121.411, http://ci.nii.ac.jp/naid/130000086006
    Summary:Protease-activated receptors (PARs) are a family of G-protein-coupled-seven-trans-membrane-domain-receptors activated by specific proteases, consisting of four family members. PAR-2, a receptor activated by trypsin, tryptase or coagulation factors VIIa and Xa, is unevenly distributed throughout the mammalian body, modulating multiple physiological functions. In the gastrointestinal tract, PAR-2 is involved in gastric mucosal cytoprotection, smooth muscle motility modulation, salivary and pancreatic exocrine secretion, intestinal ionic transport, etc. In the circulatory system, endothelial PAR-2, upon activation, induces vascular relaxation by mechanisms dependent on nitric oxide or endothelium-derived hyperpolarizing factor (EDHF), resulting in hypotension in vivo. In the respiratory system, PAR-2 appears to play a dual role, being pro- and anti-inflammatory. In the nervous system, PAR-2 present in capsaicin-sensitive sensory neurons participates in processing of pain information. PAR-2 is thus involved in a variety of physiological and pathophysiological functions. PAR-2 is now considered one of the most important molecules as a target for drug development.<br>
  • Characterization of Circulatory Modulation by Trypsin, an Endogenous Agonist for Protease-activated Receptor-2(PAR-2), Kawabata Atsufumi, Nakaya Yumiko, Wakisaka Mariko, Bulletin of Pharmaceutical Research and Technology Institute, 11, 51, 55,   2003 03 05 , http://ci.nii.ac.jp/naid/110000966531
  • Roles of the NMDA-NO pathways in the nociception / hypergesia via PAR-2, KURODA Ryotaro, KAWABATA Atsufumi, TANEDA Mamoru, 機能的脳神経外科 : 日本定位・機能神経外科学会機関誌 = Functional neurosurgery : official journal of the Japan Society for Stereotactic and Functional Neurosurgery, 41, 2, 132, 133,   2002 12 25 , http://ci.nii.ac.jp/naid/10013405621
  • PAR : Protease-activated Receptor-2 (PAR-2) : Roles in Nervous, Gastrointestinal and Circulatory Systems, KAWABATA Atsufumi, Japanese Journal of Thrombosis and Hemostasis, 13, 6, 467, 476,   2002 12 01 , 10.2491/jjsth.13.467, http://ci.nii.ac.jp/naid/130000106379
  • Peripheral PAR-2 Triggers Thermal Hyperalgesia and Nociceptive Responses in Rars, Kawabata Atsufumi, Kawao Naoyuki, Kuroda Ryoutaro, Bulletin of Pharmaceutical Research and Technology Institute, 10, 23, 32,   2002 03 05 , http://ci.nii.ac.jp/naid/110000560597
  • Pain modulation by neuronal protease-activated receptor-2 (PAR-2), KURODA Ryotaro, TANEDA Mamoru, KAWATABA Atsufumi, KAWAO Naoyuki, ITO Hideki, 機能的脳神経外科 : 日本定位・機能神経外科学会機関誌 = Functional neurosurgery : official journal of the Japan Society for Stereotactic and Functional Neurosurgery, 40, 2, 86, 87,   2001 12 25 , http://ci.nii.ac.jp/naid/10013405366
  • Antinociceptive effect of S-II cortical stimulation combined with NO synthase inhibitor 7-NI, KURODA Ryotaro, KAWABATA Atsufumi, NAKANO Naoki, UCHIYAMA Takuya, TANEDA Mamoru, 機能的脳神経外科 : 日本定位・機能神経外科学会機関誌 = Functional neurosurgery : official journal of the Japan Society for Stereotactic and Functional Neurosurgery, 40, 1, 17, 21,   2001 06 14 , http://ci.nii.ac.jp/naid/10013405198
  • The G Protein-Coupled Protease Receptor PAR(Protease-Activated Receptor) as a Novel Target for Drug Development, KAWABATA Atsufumi, YAKUGAKU ZASSHI, 121, 1, 1, 7,   2001 01 01 , 10.1248/yakushi.121.1, http://ci.nii.ac.jp/naid/10009556751
    Summary:The protease-activated receptor (PAR) is the family of G protein-coupled, seven transmembrane domain receptors, currently consisting of four members, PARs 1-4. The activation of PARs occurs by proteolytic unmasking of the N-terminal cryptic receptor-activating tethered ligand. In the past decade since the cloning of PAR-1, physiological roles that PARs play have been gradually understood and are now considered extremely extensive and important. This review describes physiological and/or pathophysiological roles of PARs in the circulatory, digestive, respiratory and central nervous systems, on the basis of our works and of those achieved by other research groups. The future perspective of studies on PARs is also discussed, focusing on the possibility of clinical application of PAR-targeted drugs.
  • Antinociceptive effect of S-II cortical stimulation combined with NO synthase inhibitor 7-NI, KURODA Ryotaro, KAWABATA Atsufumi, NAKANO Naoki, UCHIYAMA Takuya, TANEDA Mamoru, Functional neurosurgery : proceedings of the annual meeting of the Japan Society for Stereotactic and Functional Neurosurgery, 39, 2, 92, 93,   2000 12 28 , http://ci.nii.ac.jp/naid/10031136725
  • The G protein-coupled protease receptor PAR (protease-activated receptor) and pain : spinal c-fos expression in response to local administration of a PAR-2 agonist, KAWAO Naoyuki, KAWABATA Atsufumi, KURODA Ryotaro, Pain research : the journal of the Japanese Society for the Study of Pain = 日本疼痛学会誌, 15, 3,   2000 12 02 , http://ci.nii.ac.jp/naid/10013819918
  • Analgesia exerted by electric stimulation of the second somatosensory cortex : a clinical case and experimental evidence in the rat, KAWAO Naoyuki, KAWABATA Atsufumi, KURODA Ryotaro, Pain research : the journal of the Japanese Society for the Study of Pain = 日本疼痛学会誌, 14, 3,   1999 12 11 , http://ci.nii.ac.jp/naid/10008730937
  • Generation Difference in the Relationship between Hospital Pharmacists'Involvement in Clinical Activities and Job Satisfaction in Japan, Murakami Etsuko, Kawabata Atsufumi, Oda Yasuo, Bulletin of Pharmaceutical Research and Technology Institute, 7, 97, 107,   1998 12 20 , http://ci.nii.ac.jp/naid/110000560697
  • Survey on Job Functions of Hospital Pharmacists in Kansai Area, Murakami Etsuko, Kawabata Atsufumi, Iwaki Masahiro, Ogiso Taro, Suzuki Shigeo, Oda Yasuo, Kuroda Ryotaro, Kakehi Kazuaki, Mishima Masahiko, Takada Mitsutaka, Bulletin of Pharmaceutical Research and Technology Institute, 6, 93, 103,   1997 , http://ci.nii.ac.jp/naid/110000560682
  • Development of analgesic drugs for old aged people : Study on amino acids with analgesic activity, Takagi Hirosi, Kawabata Atsufumi, Manabe, Sachiko, Bulletin of Pharmaceutical Reserach and Technology Institute, 3, 3, 43, 48,   1994 , http://ci.nii.ac.jp/naid/110000560634
  • Pharmacological Studies on Drugs for Chronic Pain which occurs often in Old Aged Peoople (Report II), Tkagi Hiroshi, Kawabata Atsufumi, Umeda Nahoko, Bulletin of Pharmaceutical Research and Technology Institute, 2, 61, 65,   1993 , http://ci.nii.ac.jp/naid/110000560615
  • Pharmacological studies on drugs for chronic pain which occurs often in old aged people, Takagi Hiroshi, Kawabata Atsufumi, Kasamatsu Kazuyo, Bulletin of Pharmaceutical Research and Technology Institute, 1, 1, 100, 103,   1992 , http://ci.nii.ac.jp/naid/110000560592
  • Thrombocytopenia in SART-stressed animals - Comparison to other types of stress., Hata Taeko, Kawabata Atsufumi, Itoh Eiji, Kita Tomitaro, Japanese J. Psychosomatic Medicine, 29, 7, 651, 658,   1989 , http://ci.nii.ac.jp/naid/110001125861
    Summary:自律神経失調症の1モデル動物であるSARTストレスマウスでは, 血小板数減少, 骨髄巨核球数増加および出血時間の延長が既に報告されている。今回はこれらの現象について, SARTストレスとは異なったタイプのストレスを負荷した動物との比較の観点から, さらに詳細な検討を行った。1)ラットにおいても, マウスの場合と同様, SARTストレスによる血小板数減少は認められた。2)2日間の寒冷ストレス負荷によって血小板数の増加がみられたが, 1時間負荷および5日間の負荷では無変化であった。急性の拘束水浸ストレスマウスでは血小板数減少が認められた。電気ショックおよび拘束ストレスを急性的に負荷すると血小板数の増加が認められたが, 慢性的に負荷すると急性時の変化は消失していた。3)骨髄巨核数はSARTストレス以外のストレスによっては変化しなかった。4)拘束水浸ストレスによる血小板数の減少はストレス負荷中止3時間後には完全に回復していたが, SARTストレスによるそれは中止後5日経過してもなお認められた。5)SARTストレスにより出血時間は2倍以上に延長したが, 拘束水浸ストレスによっては約35%の延長が認められたのみであった。6-Hydroxydopamineにより体表面血流量の増加を来したマウスでは, 約50%の出血時間延長が認められた。以上の成績より, 自律神経失調症を伴ったSARTストレス動物における血小板数減少は, このストレスの1つの特徴であると考えられる。また, SARTストレスによる出血時間の延長には血小板数減少のほか, 血流量の増加も関与している可能性が示唆される。
  • Mechanisms for modulation of mouse gastrointestinal motility by proteinase-activated receptor (PAR)-1 and-2 in vitro, F Sekiguchi, N Hasegawa, K Inoshita, D Yonezawa, N Inoi, T Kanke, N Saito, A Kawabata, LIFE SCIENCES, 78, 9, 950, 957,   2006 01 , 10.1016/j.lfs.2005.06.035
    Summary:Proteinase-activated receptor (PAR)-1 or -2 modulates gastrointestinal transit in vivo. To clarify the underlying mechanisms, we characterized contraction/relaxation caused by TFLLR-NH2 and SLIGRL-NH2, PAR-1- and -2-activating peptides, respectively, in gastric and small intestinal (duodenal, jejunal and ileal) smooth muscle isolated from wild-type and PAR-2-knockout mice. Either SLIGRL-NH2 or TFLLR-NH2 caused both relaxation and contraction in the gastrointestinal preparations from wild-type animals. Apamin, a K+ channel inhibitor, tended to enhance the peptide-evoked contraction in some of the gastrointestinal preparations, whereas it inhibited relaxation responses to either peptide completely in the stomach, but only partially in the small intestine. Indomethacin reduced the contraction caused by SLIGRL-NH2 or TFLLR-NH2 in both gastric and ileal preparations, but unaffected apamin-insensitive relaxant effect of either peptide in ileal preparations. Repeated treatment with capsaicin suppressed the contractile effect of either peptide in the stomach, but not clearly in the ileum, whereas it enhanced the apamin-insensitive relaxant effect in ileal preparations. In any gastrointestinal preparations from PAR-2-knockout mice, SLIGRL-NH2, produced no responses. Thus, the inhibitory component in tension modulation by PAR-1 and -2 involves both apamin-sensitive and -insensitive mechanisms in the small intestine, but is predominantly attributable to the former mechanism in the stomach. The excitatory component in the PAR-1 and -2 modulation may be mediated, in part, by activation of capsaicin-sensitive sensory nerves and/or endogenous prostaglandin formation. Our study thus clarifies the multiple mechanisms for gastrointestinal motility modulation by PAR-1 and -2, and also provides ultimate evidence for involvement of PAR-2. (c) 2005 Elsevier Inc. All rights reserved.
  • Mechanisms for modulation of mouse gastrointestinal motility by proteinase-activated receptor (PAR)-1 and-2 in vitro, F Sekiguchi, N Hasegawa, K Inoshita, D Yonezawa, N Inoi, T Kanke, N Saito, A Kawabata, LIFE SCIENCES, 78, 9, 950, 957,   2006 01 , 10.1016/j.lfs.2005.06.035
    Summary:Proteinase-activated receptor (PAR)-1 or -2 modulates gastrointestinal transit in vivo. To clarify the underlying mechanisms, we characterized contraction/relaxation caused by TFLLR-NH2 and SLIGRL-NH2, PAR-1- and -2-activating peptides, respectively, in gastric and small intestinal (duodenal, jejunal and ileal) smooth muscle isolated from wild-type and PAR-2-knockout mice. Either SLIGRL-NH2 or TFLLR-NH2 caused both relaxation and contraction in the gastrointestinal preparations from wild-type animals. Apamin, a K+ channel inhibitor, tended to enhance the peptide-evoked contraction in some of the gastrointestinal preparations, whereas it inhibited relaxation responses to either peptide completely in the stomach, but only partially in the small intestine. Indomethacin reduced the contraction caused by SLIGRL-NH2 or TFLLR-NH2 in both gastric and ileal preparations, but unaffected apamin-insensitive relaxant effect of either peptide in ileal preparations. Repeated treatment with capsaicin suppressed the contractile effect of either peptide in the stomach, but not clearly in the ileum, whereas it enhanced the apamin-insensitive relaxant effect in ileal preparations. In any gastrointestinal preparations from PAR-2-knockout mice, SLIGRL-NH2, produced no responses. Thus, the inhibitory component in tension modulation by PAR-1 and -2 involves both apamin-sensitive and -insensitive mechanisms in the small intestine, but is predominantly attributable to the former mechanism in the stomach. The excitatory component in the PAR-1 and -2 modulation may be mediated, in part, by activation of capsaicin-sensitive sensory nerves and/or endogenous prostaglandin formation. Our study thus clarifies the multiple mechanisms for gastrointestinal motility modulation by PAR-1 and -2, and also provides ultimate evidence for involvement of PAR-2. (c) 2005 Elsevier Inc. All rights reserved.
  • Signal transduction for proteinase-activated receptor-2-triggered prostaglandin E-2 formation in human lung epithelial cells, N Kawao, M Nagataki, K Nagasawa, S Kubo, K Cushing, T Wada, F Sekiguchi, S Ichida, MD Hollenberg, WK MacNaughton, H Nishikawa, A Kawabata, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 315, 2, 576, 589,   2005 11 , 10.1124/jpet.105.089490
    Summary:We investigated proteinase-activated receptor-2 (PAR(2))-triggered signal transduction pathways causing increased prostaglandin E-2 (PGE(2)) formation in human lung-derived A549 epithelial cells. The PAR(2) agonist, SLIGRL-NH2 (Ser-Leu-Ile-Gly-Arg-Leu-amide), evoked immediate cytosolic Ca2+ mobilization and delayed (0.5-3 h) PGE(2) formation. The PAR(2)-triggered PGE(2) formation was attenuated by inhibition of the following signal pathway enzymes: cyclooxygenases 1 and 2 (COX-1 and COX-2, respectively), cytosolic Ca2+-dependent phospholipase A(2) (cPLA(2)), the mitogenactivated protein kinases (MAPKs), mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) and p38 MAPK, Src family tyrosine kinase, epidermal growth factor (EGF) receptor tyrosine kinase (EGFRK), and protein kinase C (PKC), but not by inhibition of matrix metalloproteinases. SLIGRL-NH2 caused prompt ( 5 min) and transient ERK phosphorylation, blocked in part by inhibitors of PKC and tyrosine kinases but not by an EGFRK inhibitor. SLIGRL-NH2 2 also evoked a relatively delayed (15 min) and persistent (30 min) phosphorylation of p38 MAPK, blocked by inhibitors of Src and EGFRK but not by inhibitors of COX-1 or COX-2. SLIGRL-NH2 elicited a Src inhibitor-blocked prompt (5 min) and transient phosphorylation of the EGFRK. SLIGRL-NH2 up-regulated COX-2 protein and/or mRNA levels that were blocked by inhibition of p38 MAPK, EGFRK, Src, and COX-2 but not MEK-ERK. SLIGRL-NH2 also caused COX-1-dependent up-regulation of microsomal PGE synthase-1 (mPGES-1). We conclude that PAR(2)-triggered PGE(2) formation in A549 cells involves a coordinated up-regulation of COX-2 and mPGES-1 involving cPLA(2), increased cytosolic Ca2+, PKC, Src, MEK-ERK, p38 MAPK, Src-mediated EGF receptor trans-activation, and also metabolic products of both COX-1 and COX-2.
  • Signal transduction for proteinase-activated receptor-2-triggered prostaglandin E-2 formation in human lung epithelial cells, N Kawao, M Nagataki, K Nagasawa, S Kubo, K Cushing, T Wada, F Sekiguchi, S Ichida, MD Hollenberg, WK MacNaughton, H Nishikawa, A Kawabata, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 315, 2, 576, 589,   2005 11 , 10.1124/jpet.105.089490
    Summary:We investigated proteinase-activated receptor-2 (PAR(2))-triggered signal transduction pathways causing increased prostaglandin E-2 (PGE(2)) formation in human lung-derived A549 epithelial cells. The PAR(2) agonist, SLIGRL-NH2 (Ser-Leu-Ile-Gly-Arg-Leu-amide), evoked immediate cytosolic Ca2+ mobilization and delayed (0.5-3 h) PGE(2) formation. The PAR(2)-triggered PGE(2) formation was attenuated by inhibition of the following signal pathway enzymes: cyclooxygenases 1 and 2 (COX-1 and COX-2, respectively), cytosolic Ca2+-dependent phospholipase A(2) (cPLA(2)), the mitogenactivated protein kinases (MAPKs), mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) and p38 MAPK, Src family tyrosine kinase, epidermal growth factor (EGF) receptor tyrosine kinase (EGFRK), and protein kinase C (PKC), but not by inhibition of matrix metalloproteinases. SLIGRL-NH2 caused prompt ( 5 min) and transient ERK phosphorylation, blocked in part by inhibitors of PKC and tyrosine kinases but not by an EGFRK inhibitor. SLIGRL-NH2 2 also evoked a relatively delayed (15 min) and persistent (30 min) phosphorylation of p38 MAPK, blocked by inhibitors of Src and EGFRK but not by inhibitors of COX-1 or COX-2. SLIGRL-NH2 elicited a Src inhibitor-blocked prompt (5 min) and transient phosphorylation of the EGFRK. SLIGRL-NH2 up-regulated COX-2 protein and/or mRNA levels that were blocked by inhibition of p38 MAPK, EGFRK, Src, and COX-2 but not MEK-ERK. SLIGRL-NH2 also caused COX-1-dependent up-regulation of microsomal PGE synthase-1 (mPGES-1). We conclude that PAR(2)-triggered PGE(2) formation in A549 cells involves a coordinated up-regulation of COX-2 and mPGES-1 involving cPLA(2), increased cytosolic Ca2+, PKC, Src, MEK-ERK, p38 MAPK, Src-mediated EGF receptor trans-activation, and also metabolic products of both COX-1 and COX-2.
  • Binding of a highly potent protease-activated receptor-2 (PAR2) activating peptide, [H-3]2-furoyl-LIGRL-NH2, to human PAR2, T Kanke, H Ishiwata, M Kabeya, M Saka, T Doi, Y Hattori, A Kawabata, R Plevin, BRITISH JOURNAL OF PHARMACOLOGY, 145, 2, 255, 263,   2005 05 , 10.1038/sj.bjp.0706189
    Summary:1 To determine the binding characteristics of a highly potent agonist for protease-activated receptor-2 (PAR2), 2-furoyl-Leu-Ile-Gly-Arg-Leu-amide (2-furoyl-LIGRL-NH2), whole-cell binding assays were performed utilising a radioactive ligand, [H-3] 2-furoyl-LIGRL-NH2. 2 Specific binding of [H-3] 2-furoyl-LIGRL-NH2 was observed in NCTC2544 cells, dependent upon PAR2 expression, and competitively displaced by the addition of unlabeled PAR2 agonists. Scatchard analysis of specific saturation binding suggested a single binding site, with K-d of 122&PLUSMN; 26.1 nM and a corresponding B-max of 180&PLUSMN; 6 f mol in 3.0 x 10(5) cells. 3 The relative binding affinities of a series of modified PAR2 agonist peptides obtained from competition studies paralleled their relative EC50 values for Ca2+ mobilisation assays, indicating improved binding affinities by substitution with 2-furoyl at the N-terminus serine. 4 Pretreatment of cells with trypsin reduced specific binding of [H-3] 2-furoyl-LIGRL-NH2, demonstrating direct competition between the synthetic agonist peptide and the proteolytically revealed tethered ligand for the binding site of the receptor. 5 In HCT-15 cells endogenously expressing PAR2, the binding of [H-3] 2-furoyl-LIGRL-NH2 was displaced by addition of unlabeled ligands, Ser-Leu-Ile-Gly-Lys-Val (SLIGKV-OH) or 2-furoyl-LIGRL-NH2. The relative binding affinity of 2-furoyl-LIGRL-NH2 to SLIGKV-OH was comparable to its relative EC50 value for Ca2+ mobilisation assays. 6 The binding assay was successfully performed in monolayers of PAR2 expressing NCTC2544 and human umbilical vein endothelial cells ( HUVEC), in 96- and 24- well plate formats, respectively. 7 These studies indicate that [H-3] 2-furoyl-LIGRL-NH2 binds to human PAR2 at its ligand- binding site. The use of this radioligand will be valuable for characterising chemicals that interact to PAR2.
  • Binding of a highly potent protease-activated receptor-2 (PAR2) activating peptide, [H-3]2-furoyl-LIGRL-NH2, to human PAR2, T Kanke, H Ishiwata, M Kabeya, M Saka, T Doi, Y Hattori, A Kawabata, R Plevin, BRITISH JOURNAL OF PHARMACOLOGY, 145, 2, 255, 263,   2005 05 , 10.1038/sj.bjp.0706189
    Summary:1 To determine the binding characteristics of a highly potent agonist for protease-activated receptor-2 (PAR2), 2-furoyl-Leu-Ile-Gly-Arg-Leu-amide (2-furoyl-LIGRL-NH2), whole-cell binding assays were performed utilising a radioactive ligand, [H-3] 2-furoyl-LIGRL-NH2. 2 Specific binding of [H-3] 2-furoyl-LIGRL-NH2 was observed in NCTC2544 cells, dependent upon PAR2 expression, and competitively displaced by the addition of unlabeled PAR2 agonists. Scatchard analysis of specific saturation binding suggested a single binding site, with K-d of 122&PLUSMN; 26.1 nM and a corresponding B-max of 180&PLUSMN; 6 f mol in 3.0 x 10(5) cells. 3 The relative binding affinities of a series of modified PAR2 agonist peptides obtained from competition studies paralleled their relative EC50 values for Ca2+ mobilisation assays, indicating improved binding affinities by substitution with 2-furoyl at the N-terminus serine. 4 Pretreatment of cells with trypsin reduced specific binding of [H-3] 2-furoyl-LIGRL-NH2, demonstrating direct competition between the synthetic agonist peptide and the proteolytically revealed tethered ligand for the binding site of the receptor. 5 In HCT-15 cells endogenously expressing PAR2, the binding of [H-3] 2-furoyl-LIGRL-NH2 was displaced by addition of unlabeled ligands, Ser-Leu-Ile-Gly-Lys-Val (SLIGKV-OH) or 2-furoyl-LIGRL-NH2. The relative binding affinity of 2-furoyl-LIGRL-NH2 to SLIGKV-OH was comparable to its relative EC50 value for Ca2+ mobilisation assays. 6 The binding assay was successfully performed in monolayers of PAR2 expressing NCTC2544 and human umbilical vein endothelial cells ( HUVEC), in 96- and 24- well plate formats, respectively. 7 These studies indicate that [H-3] 2-furoyl-LIGRL-NH2 binds to human PAR2 at its ligand- binding site. The use of this radioligand will be valuable for characterising chemicals that interact to PAR2.
  • 2-Furoyl-LIGRL-NH2, a potent agonist for proteinase-activated receptor-2, as a gastric mucosal cytoprotective agent in mice, A Kawabata, Y Oono, D Yonezawa, K Hiramatsu, N Inoi, F Sekiguchi, M Honjo, M Hirofuchi, T Kanke, H Ishiwata, BRITISH JOURNAL OF PHARMACOLOGY, 144, 2, 212, 219,   2005 01 , 10.1038/sj.bjp.0706059
    Summary:1 Proteinase-activated receptor-2 (PAR(2)), expressed in capsaicin-sensitive sensory neurons, plays a protective role in gastric mucosa. The present study evaluated gastric mucosal cytoprotective effect of 2-furoyl-LIGRL-NH2, a novel highly potent PAR(2) agonist, in ddY mice and in wild-type and PAR(2)-knockout mice of C57BL/6 background. 2 Gastric mucosal injury was created by oral administration of HCl/ethanol solution in the mice. The native PAR(2)-activating peptide SLIGRL-NH2, administered intraperitoneally (i.p.) at 0.3 - 1 mumol kg(-1) in combination with amastatin, an aminopeptidase inhibitor, but not alone, revealed gastric mucosal protection in ddY mice, which was abolished by ablation of capsaicin-sensitive sensory neurons. 3 I.p. administration of 2-furoyl-LIGRL-NH2 at 0.1 mumol kg(-1), without combined treatment with amastatin, exhibited gastric mucosal cytoprotective activity in ddY mice, the potency being much greater than SLIGRL-NH2 in combination with amastatin. This effect was also inhibited by capsaicin pretreatment. 4 Oral administration of 2-furoyl-LIGRL-NH2 at 0.003 - 0.03 mumol kg(-1) also protected against gastric mucosal lesion in a capsaicin-reversible manner in ddY mice. 5 I.p. 2-furoyl-LIGRL-NH2 at 0.1 - 0.3 mumol kg(-1) caused prompt salivation in anesthetized mice, whereas its oral administration at 0.003 - 1 mumol kg(-1) was incapable of eliciting salivation. 6 In wild-type, but not PAR(2)-knockout, mice of C57BL/6 background, i.p. administration of 2-furoyl-LIGRL-NH2 caused gastric mucosal protection. 7 Thus, 2-furoyl-LIGRL-NH2 is considered a potent and orally available gastric mucosal protective agent. Our data also substantiate a role for PAR2 in gastric mucosal protection and the selective nature of 2-furoyl-LIGRL-NH2.
  • Protease-activated receptor-2 (PAR-2)-related peptides induce tear secretion in rats: Involvement of PAR-2 and non-PAR-2 mechanisms, H Nishikawa, K Kawai, M Tanaka, H Ohtani, S Tanaka, C Kitagawa, M Nishida, T Abe, H Araki, A Kawabata, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 312, 1, 324, 331,   2005 01 , 10.1124/jpet.104.072074
    Summary:Protease-activated receptor-2 (PAR-2) plays an extensive role in the regulation of digestive exocrine secretion. The present study examined whether PAR-2-related peptides could modulate tear secretion in rats and analyzed the underlying mechanisms. SLIGRL-NH2, a PAR-2-activating peptide (PAR-2-AP) derived from mouse/rat PAR-2, when administered i.v. in combination with amastatin, an aminopeptidase inhibitor, evoked tear secretion, whereas LRGILS-NH2, a PAR-2-inactive reversed peptide, had no such effect. In contrast, LSIGRL-NH2, a partially reversed peptide known to be inactive with PAR-2, caused tear secretion equivalent to the effect of SLIGRL-NH2. SLIGKV-NH2, a human-derived PAR-2-AP, also induced significant tear secretion though to a lesser extent, whereas neither VKGILS-NH2, a reversed peptide, nor LSIGKV-NH2, a partially reversed peptide, produced any secretion. In desensitization experiments, after the first dose of SLIGRL-NH2, the second dose of SLIGRL-NH2 produced no tear secretion, whereas the response to LSIGRL-NH2 was only partially inhibited by preadministration of SLIGRL-NH2. Preadministration of LSIGRL-NH2 abolished the response to subsequently administered LSIGRL-NH2 but not SLIGRL-NH2. The tear secretion induced by LSIGRL-NH2 but not by PAR-2-APs was blocked by atropine or hexamethonium. Mast cell depletion due to repeated doses of compound 48/80 did not alter the effect of SLIGRL-NH2 or LSIGRL-NH2. Finally, IGRL-NH2, a possible core structure of LSIGRL-NH2, triggered tear secretion in an atropine-reversible manner. Our findings suggest that the PAR-2-APs SLIGRL-NH2 and SLIGKV-NH2 cause tear secretion, most likely via PAR-2 and that LSIGRL-NH2, a PAR-2-inactive peptide, and IGRL-NH2, its key structure, trigger tear secretion by stimulating parasympathetic nerves via an unidentified target molecule.
  • PAR-2 as a target for gastric mucosal protection, Drugs of Future, in press,   2005 , 10.1358/dof.2005.030.08.933192
  • 2-Furoyl-LIGRL-NH2, a potent agonist for proteinase-activated receptor-2, as a gastric mucosal cytoprotective agent in mice, A Kawabata, Y Oono, D Yonezawa, K Hiramatsu, N Inoi, F Sekiguchi, M Honjo, M Hirofuchi, T Kanke, H Ishiwata, BRITISH JOURNAL OF PHARMACOLOGY, 144, 2, 212, 219,   2005 01 , 10.1038/sj.bjp.0706059
    Summary:1 Proteinase-activated receptor-2 (PAR(2)), expressed in capsaicin-sensitive sensory neurons, plays a protective role in gastric mucosa. The present study evaluated gastric mucosal cytoprotective effect of 2-furoyl-LIGRL-NH2, a novel highly potent PAR(2) agonist, in ddY mice and in wild-type and PAR(2)-knockout mice of C57BL/6 background. 2 Gastric mucosal injury was created by oral administration of HCl/ethanol solution in the mice. The native PAR(2)-activating peptide SLIGRL-NH2, administered intraperitoneally (i.p.) at 0.3 - 1 mumol kg(-1) in combination with amastatin, an aminopeptidase inhibitor, but not alone, revealed gastric mucosal protection in ddY mice, which was abolished by ablation of capsaicin-sensitive sensory neurons. 3 I.p. administration of 2-furoyl-LIGRL-NH2 at 0.1 mumol kg(-1), without combined treatment with amastatin, exhibited gastric mucosal cytoprotective activity in ddY mice, the potency being much greater than SLIGRL-NH2 in combination with amastatin. This effect was also inhibited by capsaicin pretreatment. 4 Oral administration of 2-furoyl-LIGRL-NH2 at 0.003 - 0.03 mumol kg(-1) also protected against gastric mucosal lesion in a capsaicin-reversible manner in ddY mice. 5 I.p. 2-furoyl-LIGRL-NH2 at 0.1 - 0.3 mumol kg(-1) caused prompt salivation in anesthetized mice, whereas its oral administration at 0.003 - 1 mumol kg(-1) was incapable of eliciting salivation. 6 In wild-type, but not PAR(2)-knockout, mice of C57BL/6 background, i.p. administration of 2-furoyl-LIGRL-NH2 caused gastric mucosal protection. 7 Thus, 2-furoyl-LIGRL-NH2 is considered a potent and orally available gastric mucosal protective agent. Our data also substantiate a role for PAR2 in gastric mucosal protection and the selective nature of 2-furoyl-LIGRL-NH2.
  • Physiology and pathophysiology of proteinase-activated receptors (PARs): PARs in the respiratory system: Cellular signaling and physiological/ pathological roles, Atsufumi Kawabata, Naoyuki Kawao, Journal of Pharmacological Sciences, 97, 1, 20, 24,   2005 01 , 10.1254/jphs.FMJ04005X4
    Summary:Proteinase-activated receptors (PARs), a family of G protein-coupled receptors, are widely distributed in the mammalian body, playing a variety of physiological/pathophysiological roles. In the respiratory systems, PARs, particularly PAR-2 and PAR-1, are expressed in the epithelial and smooth muscle cells. In addition to the Gq/11-mediated activation of the phospholipase Cβ pathway, epithelial PAR activation causes prompt and/or delayed prostanoid formation, leading to airway smooth muscle relaxation and/or modulation of an inflammatory process. PAR-2 present in the epithelium and smooth muscle is considered primarily pro-inflammatory in the respiratory system, although PAR-2 may also be anti-inflammatory under certain conditions. In the lung epithelial cells, PAR-2 can also be activated by exogenous proteinases including house dust mite allergens, in addition to various possible endogenous agonist proteinases. Clinical evidence also suggests possible involvement of PARs, particularly PAR-2, in respiratory diseases. PARs thus appear to play critical roles in the respiratory systems, and the agonists/antagonists for PARs may serve as the novel therapeutic strategy for treatment of certain respiratory diseases including asthma. © 2005 The Japanese Pharmacological Society.
  • Physiology and pathophysiology of proteinase-activated receptors (PARs): Proteinase-activated receptor-2 (PAR-2) as a potential therapeutic target, J. Pharmacol. Sci.,   2005
  • Protease-activated receptor-2 (PAR-2)-related peptides induce tear secretion in rats: Involvement of PAR-2 and non-PAR-2 mechanisms, H Nishikawa, K Kawai, M Tanaka, H Ohtani, S Tanaka, C Kitagawa, M Nishida, T Abe, H Araki, A Kawabata, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 312, 1, 324, 331,   2005 01 , 10.1124/jpet.104.072074
    Summary:Protease-activated receptor-2 (PAR-2) plays an extensive role in the regulation of digestive exocrine secretion. The present study examined whether PAR-2-related peptides could modulate tear secretion in rats and analyzed the underlying mechanisms. SLIGRL-NH2, a PAR-2-activating peptide (PAR-2-AP) derived from mouse/rat PAR-2, when administered i.v. in combination with amastatin, an aminopeptidase inhibitor, evoked tear secretion, whereas LRGILS-NH2, a PAR-2-inactive reversed peptide, had no such effect. In contrast, LSIGRL-NH2, a partially reversed peptide known to be inactive with PAR-2, caused tear secretion equivalent to the effect of SLIGRL-NH2. SLIGKV-NH2, a human-derived PAR-2-AP, also induced significant tear secretion though to a lesser extent, whereas neither VKGILS-NH2, a reversed peptide, nor LSIGKV-NH2, a partially reversed peptide, produced any secretion. In desensitization experiments, after the first dose of SLIGRL-NH2, the second dose of SLIGRL-NH2 produced no tear secretion, whereas the response to LSIGRL-NH2 was only partially inhibited by preadministration of SLIGRL-NH2. Preadministration of LSIGRL-NH2 abolished the response to subsequently administered LSIGRL-NH2 but not SLIGRL-NH2. The tear secretion induced by LSIGRL-NH2 but not by PAR-2-APs was blocked by atropine or hexamethonium. Mast cell depletion due to repeated doses of compound 48/80 did not alter the effect of SLIGRL-NH2 or LSIGRL-NH2. Finally, IGRL-NH2, a possible core structure of LSIGRL-NH2, triggered tear secretion in an atropine-reversible manner. Our findings suggest that the PAR-2-APs SLIGRL-NH2 and SLIGKV-NH2 cause tear secretion, most likely via PAR-2 and that LSIGRL-NH2, a PAR-2-inactive peptide, and IGRL-NH2, its key structure, trigger tear secretion by stimulating parasympathetic nerves via an unidentified target molecule.
  • Receptor-activating peptides for PAR-1 and PAR-2 relax rat gastric artery via multiple mechanisms, A Kawabata, Y Nakaya, T Ishiki, S Kubo, R Kuroda, F Sekiguchi, N Kawao, H Nishikawa, K Kawai, LIFE SCIENCES, 75, 22, 2689, 2702,   2004 10 , 10.1016/j.lfs.2004.07.006
    Summary:Receptor-activating peptides for protease-activated receptors (PARs) 1 or 2 enhance gastric mucosal blood flow 1 (GMBF) and protect against gastric mucosal injury in rats. We thus examined and characterized the effects of PARI and PAR-2 agonists on the isometric tension in isolated rat gastric artery. The agonists for PAR-2 or PAR-1 produced vasodilation in the endothelium-intact arterial rings, which was abolished by removal of the endothelium. The mechanisms underlying the PAR-2- and PAR-1-mediated relaxation involved NO, endothelium-derived hyperpolarizing factor (EDHF) and prostanoids, to distinct extent, as evaluated by use of inhibitors of NO synthase, cyclo-oxygenase and Ca2+-activated K+ channels. The EDHF-dependent relaxation responses were significantly attenuated by gap junction inhibitors. These findings demonstrate that endothelial PAR-1 and PAR-2, upon activation, dilate the gastric artery via NO and prostanoid formation and also EDHF mechanisms including gap junctions, which would enhance GMBF. (C) 2004 Elsevier Inc. All rights reserved.
  • Proteinase-activated receptor-2-mediated relaxation in mouse tracheal and bronchial smooth muscle: Signal transduction mechanisms and distinct agonist sensitivity, A Kawabata, S Kubo, T Ishiki, N Kawao, F Sekiguchi, R Kuroda, MD Hollenberg, T Kanke, N Saito, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 311, 1, 402, 410,   2004 10 , 10.1124/jpet.104.068387
    Summary:We characterized the tracheal and bronchial relaxation caused by proteinase-activated receptor-2 (PAR-2) activation in ddY mice and/or in wild-type and PAR-2-knockout mice of C57BL/6 background. Ser-Leu-Ile-Gly-Arg-Leu-amide (SLIGRL-NH2) and Thr-Phe-Leu-Leu-Arg-amide, PAR-2- and PAR-1-activating peptides, respectively, caused relaxation in the isolated ddY mouse trachea and main bronchus. The relaxation was abolished by specific inhibitors of cyclooxygenase (COX)-1, COX-2, mitogen-activated protein kinase kinase (MEK), and p38 MAP kinase. The MEK and p38 MAP kinase inhibitors did not affect prostaglandin E-2-induced relaxation. Inhibitors of cytosolic Ca2+-dependent phospholipase A(2) (PLA(2)), Ca2+-independent PLA(2), diacylglycerol lipase, tyrosine kinase, and protein kinase C exhibited no or only minor inhibitory effects on the PAR-mediated relaxation. Trypsin, a PAR-2 activator, and 2-furoyl-Leu-Ile-Gly-Arg-Leu-amide, a potent PAR-2- activating peptide, in addition to SLIGRL-NH2, caused airway relaxation in wild-type C57BL/6 mice, as in ddY mice. In PAR-2-knockout mice, the peptide effects were absent and the potency of trypsin decreased. Desensitization of PAR-2 and/or PAR-1-greatly suppressed the relaxant effect of trypsin. The bronchial and tracheal tissues displayed distinct sensitivities toward trypsin and the PAR-2-activating peptides. Our data indicate an involvement of both COX-1 and COX-2, and the MEK-extracellular signal-regulated kinase and p38 MAP kinase signaling pathways in the PAR-2- and PAR-1-triggered relaxation of mouse airway tissue, and substantiate a role for PAR-2 in regulating both the trachea and bronchial responsiveness in the mouse lung.
  • Receptor-activating peptides for PAR-1 and PAR-2 relax rat gastric artery via multiple mechanisms, A Kawabata, Y Nakaya, T Ishiki, S Kubo, R Kuroda, F Sekiguchi, N Kawao, H Nishikawa, K Kawai, LIFE SCIENCES, 75, 22, 2689, 2702,   2004 10 , 10.1016/j.lfs.2004.07.006
    Summary:Receptor-activating peptides for protease-activated receptors (PARs) 1 or 2 enhance gastric mucosal blood flow 1 (GMBF) and protect against gastric mucosal injury in rats. We thus examined and characterized the effects of PARI and PAR-2 agonists on the isometric tension in isolated rat gastric artery. The agonists for PAR-2 or PAR-1 produced vasodilation in the endothelium-intact arterial rings, which was abolished by removal of the endothelium. The mechanisms underlying the PAR-2- and PAR-1-mediated relaxation involved NO, endothelium-derived hyperpolarizing factor (EDHF) and prostanoids, to distinct extent, as evaluated by use of inhibitors of NO synthase, cyclo-oxygenase and Ca2+-activated K+ channels. The EDHF-dependent relaxation responses were significantly attenuated by gap junction inhibitors. These findings demonstrate that endothelial PAR-1 and PAR-2, upon activation, dilate the gastric artery via NO and prostanoid formation and also EDHF mechanisms including gap junctions, which would enhance GMBF. (C) 2004 Elsevier Inc. All rights reserved.
  • Proteinase-activated receptor-2-mediated relaxation in mouse tracheal and bronchial smooth muscle: Signal transduction mechanisms and distinct agonist sensitivity, A Kawabata, S Kubo, T Ishiki, N Kawao, F Sekiguchi, R Kuroda, MD Hollenberg, T Kanke, N Saito, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 311, 1, 402, 410,   2004 10 , 10.1124/jpet.104.068387
    Summary:We characterized the tracheal and bronchial relaxation caused by proteinase-activated receptor-2 (PAR-2) activation in ddY mice and/or in wild-type and PAR-2-knockout mice of C57BL/6 background. Ser-Leu-Ile-Gly-Arg-Leu-amide (SLIGRL-NH2) and Thr-Phe-Leu-Leu-Arg-amide, PAR-2- and PAR-1-activating peptides, respectively, caused relaxation in the isolated ddY mouse trachea and main bronchus. The relaxation was abolished by specific inhibitors of cyclooxygenase (COX)-1, COX-2, mitogen-activated protein kinase kinase (MEK), and p38 MAP kinase. The MEK and p38 MAP kinase inhibitors did not affect prostaglandin E-2-induced relaxation. Inhibitors of cytosolic Ca2+-dependent phospholipase A(2) (PLA(2)), Ca2+-independent PLA(2), diacylglycerol lipase, tyrosine kinase, and protein kinase C exhibited no or only minor inhibitory effects on the PAR-mediated relaxation. Trypsin, a PAR-2 activator, and 2-furoyl-Leu-Ile-Gly-Arg-Leu-amide, a potent PAR-2- activating peptide, in addition to SLIGRL-NH2, caused airway relaxation in wild-type C57BL/6 mice, as in ddY mice. In PAR-2-knockout mice, the peptide effects were absent and the potency of trypsin decreased. Desensitization of PAR-2 and/or PAR-1-greatly suppressed the relaxant effect of trypsin. The bronchial and tracheal tissues displayed distinct sensitivities toward trypsin and the PAR-2-activating peptides. Our data indicate an involvement of both COX-1 and COX-2, and the MEK-extracellular signal-regulated kinase and p38 MAP kinase signaling pathways in the PAR-2- and PAR-1-triggered relaxation of mouse airway tissue, and substantiate a role for PAR-2 in regulating both the trachea and bronchial responsiveness in the mouse lung.
  • Activation of trigeminal nociceptive neurons by parotid PAR-2 activation in rats, A Kawabata, H Itoh, N Kawao, R Kuroda, F Sekiguchi, T Masuko, K Iwata, A Ogawa, NEUROREPORT, 15, 10, 1617, 1621,   2004 07 , 10.1097/01.wnr.0000134991.97051.6b
    Summary:To clarify involvement of protease-activated receptor-2 (PAR-2) in parotid pain, we examined whether PAR-2 activation in the parotid gland could activate trigeminal nociceptive neurons in anesthetized rats, by analyzing immunoreactive Fos as a nociceptive marker. Either the PAR-2 agonist SLIGRL-NH2 or capsaicin, injected into the parotid duct, caused expression of Fos in the trigeminal subnucleus caudalis, although the PAR-2-inactive reversed peptide had no such effect. The Fos expression caused by PAR-2 activation was inhibited by ablation of capsaicin-sensitive sensory neurons. Intraductal SLIGRL-NH2 did not increase vascular permeability in the parotid gland. Our data thus reveal that activation of PAR-2 in the parotid gland can cause activation of trigeminal nociceptive neurons via capsaicin-sensitive sensory nerves most probably by a non-inflammatory mechanism.
  • Activation of trigeminal nociceptive neurons by parotid PAR-2 activation in rats, A Kawabata, H Itoh, N Kawao, R Kuroda, F Sekiguchi, T Masuko, K Iwata, A Ogawa, NEUROREPORT, 15, 10, 1617, 1621,   2004 07 , 10.1097/01.wnr.0000134991.97051.6b
    Summary:To clarify involvement of protease-activated receptor-2 (PAR-2) in parotid pain, we examined whether PAR-2 activation in the parotid gland could activate trigeminal nociceptive neurons in anesthetized rats, by analyzing immunoreactive Fos as a nociceptive marker. Either the PAR-2 agonist SLIGRL-NH2 or capsaicin, injected into the parotid duct, caused expression of Fos in the trigeminal subnucleus caudalis, although the PAR-2-inactive reversed peptide had no such effect. The Fos expression caused by PAR-2 activation was inhibited by ablation of capsaicin-sensitive sensory neurons. Intraductal SLIGRL-NH2 did not increase vascular permeability in the parotid gland. Our data thus reveal that activation of PAR-2 in the parotid gland can cause activation of trigeminal nociceptive neurons via capsaicin-sensitive sensory nerves most probably by a non-inflammatory mechanism.
  • Potent and metabolically stable agonists for protease-activated receptor-2: Evaluation of activity in multiple assay systems in vitro and in vivo, A Kawabata, T Kanke, D Yonezawa, T Ishiki, M Saka, M Kabeya, F Sekiguchi, S Kubo, R Kuroda, M Iwaki, K Katsura, R Plevin, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 309, 3, 1098, 1107,   2004 06 , 10.1124/jpet.103.061010
    Summary:To develop potent and metabolically stable agonists for protease-activated receptor-2 (PAR-2), we prepared 2-furoylated (2f) derivatives of native PAR-2-activating peptides, 2f-LIGKV-OH, 2f-LIGRL-OH, 2f-LIGKV-NH2, and 2f-LIGRL-NH2, and systematically evaluated their activity in PAR-2-responsive cell lines and tissues. In both HCT-15 cells and NCTC2544 cells overexpressing PAR-2, all furoylated peptides increased cytosolic Ca2+ levels with a greater potency than the corresponding native peptides, although a similar maximum response was recorded. The absolute potency of each peptide was greater in NCTC2544, possibly due to a higher level of receptor expression. Furthermore, the difference in potency between the 2-furoylated peptides and the native peptides was enhanced when evaluated in the rat superior mesenteric artery and further increased when measuring PAR-2-mediated salivation in ddY mice in vivo. The potency of 2f-LIGRL-NH2, the most powerful peptide, relative to SLIGKV-OH, was about 100 in the cultured cell Ca2+ signaling assays, 517 in the vasorelaxation assay, and 1100 in the salivation assay. Amastatin, an aminopeptidase inhibitor, augmented salivation caused by native peptides, but not furoylated peptides. The PAR-2-activating peptides, including the furoylated derivatives, also produced salivation in the wild-type C57BL/6 mice, but not the PAR-2-deficient mice. Our data thus demonstrate that substitution of the N-terminal serine with a furoyl group in native PAR-2-activating peptides dramatically enhances the agonistic activity and decreases degradation by aminopeptidase, leading to development of 2f-LIGRL-NH2, the most potent peptide. Furthermore, the data from PAR-2-deficient mice provide ultimate evidence for involvement of PAR-2 in salivation and the selective nature of the 2-furoylated peptides.
  • Potent and metabolically stable agonists for protease-activated receptor-2: Evaluation of activity in multiple assay systems in vitro and in vivo, A Kawabata, T Kanke, D Yonezawa, T Ishiki, M Saka, M Kabeya, F Sekiguchi, S Kubo, R Kuroda, M Iwaki, K Katsura, R Plevin, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 309, 3, 1098, 1107,   2004 06 , 10.1124/jpet.103.061010
    Summary:To develop potent and metabolically stable agonists for protease-activated receptor-2 (PAR-2), we prepared 2-furoylated (2f) derivatives of native PAR-2-activating peptides, 2f-LIGKV-OH, 2f-LIGRL-OH, 2f-LIGKV-NH2, and 2f-LIGRL-NH2, and systematically evaluated their activity in PAR-2-responsive cell lines and tissues. In both HCT-15 cells and NCTC2544 cells overexpressing PAR-2, all furoylated peptides increased cytosolic Ca2+ levels with a greater potency than the corresponding native peptides, although a similar maximum response was recorded. The absolute potency of each peptide was greater in NCTC2544, possibly due to a higher level of receptor expression. Furthermore, the difference in potency between the 2-furoylated peptides and the native peptides was enhanced when evaluated in the rat superior mesenteric artery and further increased when measuring PAR-2-mediated salivation in ddY mice in vivo. The potency of 2f-LIGRL-NH2, the most powerful peptide, relative to SLIGKV-OH, was about 100 in the cultured cell Ca2+ signaling assays, 517 in the vasorelaxation assay, and 1100 in the salivation assay. Amastatin, an aminopeptidase inhibitor, augmented salivation caused by native peptides, but not furoylated peptides. The PAR-2-activating peptides, including the furoylated derivatives, also produced salivation in the wild-type C57BL/6 mice, but not the PAR-2-deficient mice. Our data thus demonstrate that substitution of the N-terminal serine with a furoyl group in native PAR-2-activating peptides dramatically enhances the agonistic activity and decreases degradation by aminopeptidase, leading to development of 2f-LIGRL-NH2, the most potent peptide. Furthermore, the data from PAR-2-deficient mice provide ultimate evidence for involvement of PAR-2 in salivation and the selective nature of the 2-furoylated peptides.
  • Distinct roles for protease-activated receptors 1 and 2 in vasomotor modulation in rat superior mesenteric artery, A Kawabata, S Kubo, Y Nakaya, T Ishiki, R Kuroda, F Sekiguchi, N Kawao, H Nishikawa, CARDIOVASCULAR RESEARCH, 61, 4, 683, 692,   2004 03 , 10.1016/j.cardiores.2003.11.030
    Summary:Objective: Protease-activated receptors (PARs) 1 and 2 are expressed in various blood vessels including rat aorta, modulating vascular tone. We investigated the roles of PAR-1 and PAR-2 in vasomotor modulation in rat superior mesenteric artery. Methods and results: Effects of the PAR-2-activating peptide Ser-Leu-Ile-Gly-Arg-Leu-amide (SLIGRL-amide) and the PAR-1-activating peptide Thr-Phe-Leu-Leu-Argamide (TFLLR-amide) on isometric tension were examined in isolated rat superior mesenteric artery or aorta. Both SLIGRL-amide and TFLLR-amide caused relaxation in the precontracted rat aortic rings. The latter peptide, but not the former, produced contraction in the resting rings. N-G-nitro-L-arginine methyl ester (L-NAME), but not apamin/charybdotoxin known to block the endothelium-derived hyperpolarizing factor (EDHF) pathway, abolished the relaxation and facilitated the contraction. In the precontracted rat superior mesenteric artery, SLIGRL-amide, but not TFLLR-amide, elicited endothelium-dependent relaxation, which was only partially inhibited by L-NAME with and without indomethacin. The residual relaxation was abolished by apamin/charybdotoxin. Carbenoxolone, a gap junction inhibitor, significantly attenuated the SLIGRL-amide-evoked, EDHF-dependent relaxation, although neither 17-octadecynoic acid, a P450 epoxygenase inhibitor, nor catalase, a hydrogen peroxide scavenger, revealed inhibitory effects. The residual response resistant to carbenoxolone was unaffected by ouabain/BaCl2. In the resting artery, TFLLR-amide, but not SLIGRL-amide, produced only slight contraction, which was dramatically facilitated by combination of L-NAME and apamin/charybdotoxin or by removal of the endothelium. Conclusions: Our data suggest that, in rat superior mesenteric artery, endothelial PAR-2, upon activation, causes relaxation via both NO and EDHF pathways, and that activation of muscular PAR-1 exhibits potential contractile activity that is largely masked by NO and EDHFs pathways triggered by endothelial PAR-1. Gap junctions might be involved in the EDHF mechanisms in this artery. (C) 2004 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.
  • A protective role of protease-activated receptor 1 in rat gastric mucosa, A Kawabata, H Nishikawa, H Saitoh, Y Nakaya, K Hiramatsu, S Kubo, M Nishida, N Kawao, R Kuroda, F Sekiguchi, M Kinoshita, K Kakehi, N Arizono, H Yamagishi, K Kawai, GASTROENTEROLOGY, 126, 1, 208, 219,   2004 01 , 10.1053/j.gastro.2003.10.071
    Summary:Background & Aims: On activation, protease-activated receptor (PAR)-2 modulates multiple gastric functions and exerts mucosal protection via activation of sensory neurons. The role of PAR-1, a thrombin receptor, in the stomach remains unknown. We thus examined if the PAR-1 agonist could protect against gastric mucosal injury in rats. Methods: Gastric mucosal injury was created by oral administration of ethanol/HCl or absolute ethanol in conscious rats. Gastric mucosal blood flow and acid secretion were determined in anesthetized rats. Immunohistochemical analyses of PAR-1 and cyclooxygenase (COX)-1 were also performed in rat and human stomach. Results: The PAR-1 agonist TFLLR-NH2, administered intravenously in combination with amastatin, protected against the gastric mucosal injury induced by ethanol/HCl or absolute ethanol. The protective effect of TFLLR-NH2 was abolished by indomethacin or a COX-1 inhibitor but not by ablation of sensory neurons with capsaicin. TFLLR-NH2 produced an NO-independent increase in gastric mucosal blood flow that was partially inhibited by blockade of the endothelium-derived hyperpolarizing factor pathway. This inhibitory effect was promoted by indomethacin. TFLLR-NH2 suppressed carbachol-evoked acid secretion in an indomethacin-reversible manner. Immunoreactive PAR-1 and COX-1 were expressed abundantly in rat gastric muscularis mucosae and smooth muscle, and the former protein was also detectable in blood vessels. Similar staining was observed in human gastric muscularis mucosae. Conclusions: The PAR-1. agonist, given systemically, protects against gastric mucosal injury via COX-1-dependent formation of prostanoids, modulating multiple gastric functions. Our data identify a novel protective role for PAR-1 in gastric mucosa, and the underlying mechanism is entirely different from that for PAR-2.
  • Impact of a pharmacist-implemented anemia management in outpatients with end-stage renal disease in Japan, Biol. Pharm. Bull., 27, 1831-1833,   2004 , 10.1248/bpb.27.1831
  • Protease-activated receptors (PARs) as therapeutic targets: development of agonists/antagonists and modulation of gastrointestinal functions, Drug Design Reviews, 1, 287-296,   2004
  • PAR (protease-activated receptor), 生体の科学, 55, 520-521,   2004 , 10.11477/mf.2425100632
  • The potent iNOS inhibitor ONO-1714 inhibits nNOS and exerts antinociception in rats, Neurosci. Lett., 365, 111-115,   2004 , 10.1016/j.neulet.2004.04.069
  • Modulation of capsaicin-evoked visceral pain and referred hyperalgesia by protease-activated receptors 1 and 2, J. Pharmacol. Sci., 94, 277-285,   2004 , 10.1254/jphs.94.277
  • A protective role of protease-activated receptor 1 in rat gastric mucosa, A Kawabata, H Nishikawa, H Saitoh, Y Nakaya, K Hiramatsu, S Kubo, M Nishida, N Kawao, R Kuroda, F Sekiguchi, M Kinoshita, K Kakehi, N Arizono, H Yamagishi, K Kawai, GASTROENTEROLOGY, 126, 1, 208, 219,   2004 01 , 10.1053/j.gastro.2003.10.071
    Summary:Background & Aims: On activation, protease-activated receptor (PAR)-2 modulates multiple gastric functions and exerts mucosal protection via activation of sensory neurons. The role of PAR-1, a thrombin receptor, in the stomach remains unknown. We thus examined if the PAR-1 agonist could protect against gastric mucosal injury in rats. Methods: Gastric mucosal injury was created by oral administration of ethanol/HCl or absolute ethanol in conscious rats. Gastric mucosal blood flow and acid secretion were determined in anesthetized rats. Immunohistochemical analyses of PAR-1 and cyclooxygenase (COX)-1 were also performed in rat and human stomach. Results: The PAR-1 agonist TFLLR-NH2, administered intravenously in combination with amastatin, protected against the gastric mucosal injury induced by ethanol/HCl or absolute ethanol. The protective effect of TFLLR-NH2 was abolished by indomethacin or a COX-1 inhibitor but not by ablation of sensory neurons with capsaicin. TFLLR-NH2 produced an NO-independent increase in gastric mucosal blood flow that was partially inhibited by blockade of the endothelium-derived hyperpolarizing factor pathway. This inhibitory effect was promoted by indomethacin. TFLLR-NH2 suppressed carbachol-evoked acid secretion in an indomethacin-reversible manner. Immunoreactive PAR-1 and COX-1 were expressed abundantly in rat gastric muscularis mucosae and smooth muscle, and the former protein was also detectable in blood vessels. Similar staining was observed in human gastric muscularis mucosae. Conclusions: The PAR-1. agonist, given systemically, protects against gastric mucosal injury via COX-1-dependent formation of prostanoids, modulating multiple gastric functions. Our data identify a novel protective role for PAR-1 in gastric mucosa, and the underlying mechanism is entirely different from that for PAR-2.
  • Effect of a potent iNOS inhibitor (ONO-1714) on acetaminophen-induced hepatotoxicity in the rat, Y Kamanaka, A Kawabata, H Matsuya, C Taga, F Sekiguchi, N Kawao, LIFE SCIENCES, 74, 6, 793, 802,   2003 12 , 10.1016/j.lfs.2003.09.036
    Summary:Overproduction of nitric oxide (NO) in the liver has been implicated as an important event in endotoxin shock and in other models of hepatic inflammation and injury. The present study was undertaken to evaluate the effect of ONO-1714, a potent and specific inhibitor of inducible NO synthase (iNOS), on acetaminophen-induced hepatotoxicity in the rats. Oral administration of ONO-1714 dose-dependently inhibited NOx (NO2 and NO3-) accumulation in rat plasma after lipopolysaccharide (LPS) treatment. Intraperitoneal acetaminophen at 1 g/kg caused damage to the centrilobular regions of the liver and increase in serum alanine and aspartate transaminase (ALT and AST, respectively) levels accompanied by elevated plasma NOx levels after 24 h. Oral administration of ONO-1714 at 10 and 100 mug/kg dose-dependently reduced the acetaminophen-induced hepatic tissue damage and the increases in serum ALT and AST levels. ONO-1714 also blocked the increase in plasma NOx concentrations. These findings demonstrate that oral ONO-1714, an iNOS inhibitor, protects against acetaminophen-evoked hepatic inflammation/injury, strongly suggesting that NO produced by iNOS plays a key role in the pathogenesis of this drug-induced hepatotoxicity. (C) 2003 Elsevier Inc. All rights reserved.
  • Effect of a potent iNOS inhibitor (ONO-1714) on acetaminophen-induced hepatotoxicity in the rat, Y Kamanaka, A Kawabata, H Matsuya, C Taga, F Sekiguchi, N Kawao, LIFE SCIENCES, 74, 6, 793, 802,   2003 12 , 10.1016/j.lfs.2003.09.036
    Summary:Overproduction of nitric oxide (NO) in the liver has been implicated as an important event in endotoxin shock and in other models of hepatic inflammation and injury. The present study was undertaken to evaluate the effect of ONO-1714, a potent and specific inhibitor of inducible NO synthase (iNOS), on acetaminophen-induced hepatotoxicity in the rats. Oral administration of ONO-1714 dose-dependently inhibited NOx (NO2 and NO3-) accumulation in rat plasma after lipopolysaccharide (LPS) treatment. Intraperitoneal acetaminophen at 1 g/kg caused damage to the centrilobular regions of the liver and increase in serum alanine and aspartate transaminase (ALT and AST, respectively) levels accompanied by elevated plasma NOx levels after 24 h. Oral administration of ONO-1714 at 10 and 100 mug/kg dose-dependently reduced the acetaminophen-induced hepatic tissue damage and the increases in serum ALT and AST levels. ONO-1714 also blocked the increase in plasma NOx concentrations. These findings demonstrate that oral ONO-1714, an iNOS inhibitor, protects against acetaminophen-evoked hepatic inflammation/injury, strongly suggesting that NO produced by iNOS plays a key role in the pathogenesis of this drug-induced hepatotoxicity. (C) 2003 Elsevier Inc. All rights reserved.
  • Gastrointestinal functions of proteinase-activated receptors, A Kawabata, LIFE SCIENCES, 74, 2-3, 247, 254,   2003 12 , 10.1016/j.lfs.2003.09.011
    Summary:Proteinase-activated receptors (PARs) are a family of G-protein-coupled-seven-trans-membrane-domain receptors, consisting of four family members. PARs, especially PAR-1, a thrombin receptor, and PAR-2, a receptor for trypsin, tryptase and coagulation factors VIIa and Xa, are abundantly distributed throughout the gastrointestinal tract. PAR-2, but not other PARs, induces salivary and pancreatic exocrine secretion., Both PAR-2 and PAR-1 play protective roles in the gastric mucosa, modulating a variety of gastric functions. However, the mechanisms underlying the mucosal protection caused by PAR-2 and PAR-1 are entirely different. In the intestinal mucosa, PAR-2 appears to play a dual role, being pro- and anti-inflammatory. PAR-1, PAR-2 and also PAR-4 modulate the motility of the smooth muscle in the gastrointestinal tract. including the esophageal muscularis mucosae, producing contraction and/or relaxation upon activation. Thus, PARs, especially PAR-1 and PAR-2, play extensive roles in modulating the gastrointestinal functions. (C) 2003 Elsevier Inc. All rights reserved.
  • The PAR-1-activating peptide facilitates pepsinogen secretion in rats, N Kawao, K Hiramatsu, N Inoi, R Kuroda, H Nishikawa, F Sekiguchi, A Kawabata, PEPTIDES, 24, 9, 1449, 1451,   2003 09 , 10.1016/j.peptides.2003.08.010
    Summary:Protease-activated receptor-2 (PAR-2) is abundantly expressed in gastric mucosal chief cells, facilitating pepsinogen secretion. In the present study, we investigated whether PAR-1, a thrombin receptor, could modulate pepsinogen secretion in rats. The PAR-1-activating peptide TFLLR-NH2 as well as the PAR-2-activating peptide SLIGRL-NH2, administered i.v. repeatedly at 1-h intervals, significantly increased gastric pepsinogen secretion over 2-4 h (after two to four doses). In contrast, the control peptide FTLLR-NH2, given in the same manner, had no such effect. Thus, PAR-1, like PAR-2, might function to facilitate pepsinogen secretion, suggesting a novel role of the thrombin-PAR-1-pathway in the stomach. (C) 2003 Elsevier Inc. All rights reserved.
  • Involvement of EDHF in the hypotension and increased gastric mucosal blood flow caused by PAR-2 activation in rats, A Kawabata, Y Nakaya, R Kuroda, M Wakisaka, T Masuko, H Nishikawa, K Kawai, BRITISH JOURNAL OF PHARMACOLOGY, 140, 2, 247, 254,   2003 09 , 10.1038/sj.bjp.0705433
    Summary:1 Agonists for protease-activated receptor-2(PAR-2) cause hypotension and an increase in gastric mucosal blood flow (GMBF) in vivo. We thus studied the mechanisms underlying the circulatory modulation by PAR-2 activation in vivo, especially with respect to involvement of endothelium-derived hyperpolarizing factor (EDHF). 2 Arterial blood pressure and GMBF were measured in anesthetized rats in vivo. Vascular relaxation was assessed in the precontracted rat gastric arterial rings in vitro. 3 The PAR-2-activating peptide SLIGRL-NH2 and/or trypsin, administered i.v., produced largely NO-independent hypotension and increase in GMBF accompanied by decreased gastric mucosal vascular resistance (GMVR) in rats. 4 Combined administration of apamin and charybdotoxin, but not each of them, specifically abolished the hypotension, increased GMBF and decreased GMVR caused by the PAR-2 agonists. 5 In the isolated rat gastric artery, SLIGRL-NH2 elicited endothelium-dependent relaxation even in the presence of an NO synthase inhibitor and indomethacin, which was abolished by apamin plus charybdotoxin. 6 Our data suggest involvement of apamin/charybdotoxin-sensitive K+ channels in the PAR-2-triggered hypotension and increased GMBF, predicting a role of EDHF-like factors.
  • The PAR-1-activating peptide facilitates pepsinogen secretion in rats, N Kawao, K Hiramatsu, N Inoi, R Kuroda, H Nishikawa, F Sekiguchi, A Kawabata, PEPTIDES, 24, 9, 1449, 1451,   2003 09 , 10.1016/j.peptides.2003.08.010
    Summary:Protease-activated receptor-2 (PAR-2) is abundantly expressed in gastric mucosal chief cells, facilitating pepsinogen secretion. In the present study, we investigated whether PAR-1, a thrombin receptor, could modulate pepsinogen secretion in rats. The PAR-1-activating peptide TFLLR-NH2 as well as the PAR-2-activating peptide SLIGRL-NH2, administered i.v. repeatedly at 1-h intervals, significantly increased gastric pepsinogen secretion over 2-4 h (after two to four doses). In contrast, the control peptide FTLLR-NH2, given in the same manner, had no such effect. Thus, PAR-1, like PAR-2, might function to facilitate pepsinogen secretion, suggesting a novel role of the thrombin-PAR-1-pathway in the stomach. (C) 2003 Elsevier Inc. All rights reserved.
  • Involvement of EDHF in the hypotension and increased gastric mucosal blood flow caused by PAR-2 activation in rats, A Kawabata, Y Nakaya, R Kuroda, M Wakisaka, T Masuko, H Nishikawa, K Kawai, BRITISH JOURNAL OF PHARMACOLOGY, 140, 2, 247, 254,   2003 09 , 10.1038/sj.bjp.0705433
    Summary:1 Agonists for protease-activated receptor-2(PAR-2) cause hypotension and an increase in gastric mucosal blood flow (GMBF) in vivo. We thus studied the mechanisms underlying the circulatory modulation by PAR-2 activation in vivo, especially with respect to involvement of endothelium-derived hyperpolarizing factor (EDHF). 2 Arterial blood pressure and GMBF were measured in anesthetized rats in vivo. Vascular relaxation was assessed in the precontracted rat gastric arterial rings in vitro. 3 The PAR-2-activating peptide SLIGRL-NH2 and/or trypsin, administered i.v., produced largely NO-independent hypotension and increase in GMBF accompanied by decreased gastric mucosal vascular resistance (GMVR) in rats. 4 Combined administration of apamin and charybdotoxin, but not each of them, specifically abolished the hypotension, increased GMBF and decreased GMVR caused by the PAR-2 agonists. 5 In the isolated rat gastric artery, SLIGRL-NH2 elicited endothelium-dependent relaxation even in the presence of an NO synthase inhibitor and indomethacin, which was abolished by apamin plus charybdotoxin. 6 Our data suggest involvement of apamin/charybdotoxin-sensitive K+ channels in the PAR-2-triggered hypotension and increased GMBF, predicting a role of EDHF-like factors.
  • Modulation of gastric functions by PARs, Drug Dev. Res., 60, 9, 13,   2003 , 10.1002/ddr.10313
  • Multiple roles for protease-activated receptor-2 in gastric mucosa., Inflammopharmacology, 10, 343, 349,   2003
  • Effects of somatosensory cortical stimulation on expression of c-Fos in rat medullary dorsal horn in response to formalin-induced noxious stimulation, F Gojyo, S Sugiyo, R Kuroda, A Kawabata, Varathan, V, Y Shigenaga, M Takemura, JOURNAL OF NEUROSCIENCE RESEARCH, 68, 4, 479, 488,   2002 05 , 10.1002/jnr.10227
    Summary:We examined the effects of epidural electrical stimulation of primary (SI) and secondary (SII) somatosensory cortex on expression of c-Fos protein in rat medullary dorsal horn neurons (Vc; trigeminal nucleus caudalis) in response to formalin-induced noxious stimulation. Epidural electrical stimulation (single pulse, 0.2 msec duration at 10 Hz) was applied to the left facial region SI or SII at three different stimulus intensities, 0.1, 0.5, and 1.0 mA for 60 min 0 or 2 hr after bilateral injection of formalin into the lower lip. SII stimulation at 1.0 mA immediately after injection of formalin, significantly decreased the number of Fos-positive cells in the right VcI/II by 32.4%. There was no significant change in the number of Fos-positive cells in the VcIII/IV. SII stimulation at 0.5 and 1.0 mA 2 hr after injection of formalin, significantly decreased the number of Fos-positive cells in the right VcI/II by 47.9% and 40.8%, but significantly increased the number of Fos-positive cells in the right VcIII.IV by 178.8% and 324.3%, respectively. In contrast, SI stimulation had no effect on expression of c-Fos in Vc. Possible direct corticotrigeminal projections were labeled anterogradely by injection of WGA-HRP into the SI and SII. In the Vc, labeled terminals were distributed mostly in the contralateral medial half of VcIII/IV and medullary reticular nucleus dorsalis but rarely in VcI/II. These results suggest that activation of SII-medullary fibers suppress nociceptive information from the oro-facial regions. (C) 2002 Wiley-Liss, Inc.
  • Effects of somatosensory cortical stimulation on expression of c-Fos in rat medullary dorsal horn in response to formalin-induced noxious stimulation, F Gojyo, S Sugiyo, R Kuroda, A Kawabata, Varathan, V, Y Shigenaga, M Takemura, JOURNAL OF NEUROSCIENCE RESEARCH, 68, 4, 479, 488,   2002 05 , 10.1002/jnr.10227
    Summary:We examined the effects of epidural electrical stimulation of primary (SI) and secondary (SII) somatosensory cortex on expression of c-Fos protein in rat medullary dorsal horn neurons (Vc; trigeminal nucleus caudalis) in response to formalin-induced noxious stimulation. Epidural electrical stimulation (single pulse, 0.2 msec duration at 10 Hz) was applied to the left facial region SI or SII at three different stimulus intensities, 0.1, 0.5, and 1.0 mA for 60 min 0 or 2 hr after bilateral injection of formalin into the lower lip. SII stimulation at 1.0 mA immediately after injection of formalin, significantly decreased the number of Fos-positive cells in the right VcI/II by 32.4%. There was no significant change in the number of Fos-positive cells in the VcIII/IV. SII stimulation at 0.5 and 1.0 mA 2 hr after injection of formalin, significantly decreased the number of Fos-positive cells in the right VcI/II by 47.9% and 40.8%, but significantly increased the number of Fos-positive cells in the right VcIII.IV by 178.8% and 324.3%, respectively. In contrast, SI stimulation had no effect on expression of c-Fos in Vc. Possible direct corticotrigeminal projections were labeled anterogradely by injection of WGA-HRP into the SI and SII. In the Vc, labeled terminals were distributed mostly in the contralateral medial half of VcIII/IV and medullary reticular nucleus dorsalis but rarely in VcI/II. These results suggest that activation of SII-medullary fibers suppress nociceptive information from the oro-facial regions. (C) 2002 Wiley-Liss, Inc.
  • Protease-activated receptor-2 (PAR-2) in the pancreas and parotid gland: immunolocalization and involvement of nitric oxide in the evoked amylase secretion., Life Sci., 71, 2435-2446,   2002 , 10.1016/S0024-3205(02)02044-1
  • Role of N-methyl-D-aspartate receptors and the NO pathway in nociception/hyperlgesia elicited by PAR-2 activation in mice and rats., Neurosci. Lett., 329, 349-353,   2002 , 10.1016/S0304-3940(02)00702-4
  • Suppression by protease-activated receptor-2 activation of gastric acid secretion in rats., Eur. J. Pharmacol., 447, 87-90,   2002 , 10.1016/S0014-2999(02)01892-7
  • The PAR-1-activating peptide attenuates carrageenan-induced hyperalgesia in rats., Peptides, 23, 1171-1175,   2002
  • Capsazepine inhibits thermal hyperalgesia but not nociception triggered by protease-activated receptor-2 in rats., Jpn. J. Pharmacol., 89, 184-187,   2002 , 10.1254/jjp.89.184
  • Protease-activated receptor-2 in the rat gastric mucosa: immunolocalization and facilitation of pepsin/pepsinogen secretion., Br. J. Pharmacol., 135, 1292-1296,   2002 , 10.1038/sj.bjp.0704562
  • Specific expression of spinal Fos following PAR-2 stimulation in mast cell-depleted rats., NeuroReport, 13, 511-514,   2002
  • Capsazepine partially inhibits the neurally mediated gastric mucus secretion following activation of protease-activated receptor-2., Clin. Exp. Pharmacol. Physiol., 29, 360-361,   2002 , 10.1046/j.1440-1681.2002.03641.x
  • The protease-activated receptor-2 agonist induces gastric mucus secretion and mucosal cytoprotection, A Kawabata, M Kinoshita, H Nishikawa, R Kuroda, M Nishida, H Araki, N Arizono, Y Oda, K Kakehi, JOURNAL OF CLINICAL INVESTIGATION, 107, 11, 1443, 1450,   2001 06
    Summary:Protease-activated receptor-2 (PAR-2), a receptor activated by trypsin/tryptase, modulates smooth muscle tone and exocrine secretion in the salivary glands and pancreas. Given that PAR-2 is expressed throughout the gastrointestinal tract, rye investigated effects of PAR-2 agonists on mucus secretion and gastric mucosal injury in the rat. PAR-2-activating peptides triggered secretion of mucus in the stomach, but not in the duodenum. This mucus secretion was abolished by pretreatment with capsaicin, which stimulates and ablates specific sensory neurons, but: it was resistant to cyclo-oxygenase inhibition. In contrast, capsaicin treatment failed to block PAR-2-mediated secretion from the salivary glands. Intravenous calcitonin gene-related peptide (CGRP) and neurokinin A markedly elicited gastric mucus secretion, as did substance P to a lesser extent. Specific antagonists of the CGRP(1) and NK2, but not the NK1, receptors inhibited PAR-2-mediated mucus secretion. Pretreatment with the PAR-2 agonist strongly prevented gastric injury caused by HCl-ethanol or indomethacin. Thus, PAR-2 activation triggers the cytoprotective secretion of gastric mucus by stimulating the release of CGRP and tachykinins from sensory neurons. In contrast, the PAR-2-mediated salivary exocrine secretion appears to be independent of capsaicin-sensitive sensory neurons.
  • Secondary somatosensory cortex stimulation facilitates the antinociceptive effect of the NO synthase inhibitor through suppression of spinal nociceptive neurons in the rat, R Kurado, N Kawao, H Yoshimura, W Umeda, M Takemura, Y Shigenaga, A Kawabata, BRAIN RESEARCH, 903, 1-2, 110, 116,   2001 06 , 10.1016/S0006-8993(01)02446-5
    Summary:Electrical stimulation of the secondary somatosensory cortex (S-II), which is clinically effective in some chronic pain patients, produces a weak antinociception by itself and also strongly facilitates the antinociceptive effect of the neuronal NO synthase inhibitor 7-nitro-indazole in laboratory animals (rats). The present study thus investigated the mechanisms by which S-II stimulation facilitates the 7-nitro-indazole-induced antinociception. S-II stimulation in combination with 7-nitro-indazole at a subeffective dose, 5 mg/kg, synergistically reduced the number of cells expressing c-Fos in response to intraplantar injection of formalin in the superficial regions (laminae I and II) of the L4 and L5 spinal dorsal horn in conscious rats, although each had no significant effect. A similar synergism produced by S-II stimulation and 7-nitro-indazole was also confirmed in both the first and second phases in the formalin-induced behavioral nociception test. The synergistic antinociception exerted by S-II stimulation in combination with 7-nitro-indazole was resistant to systemic administration of the opioid antagonist naloxone or the alpha -adrenoceptor antagonist phentolanline. In contrast, intrathecally administered methysergide, a serotonin receptor antagonist, at 20 mug/rat. abolished the first-phase, but not the second-phase, antinociception following S-II stimulation in combination with 7-nitro-indazole. These findings suggest that S-II stimulation, in combination with inhibition of neuronal NO synthase, can suppress spinal nociceptive neurons, at least in part through the descending spinal serotonergic pathway, resulting in antinociception. (C) 2001 Elsevier Science B.V. All rights reserved.
  • Factor Xa-evoked relaxation in rat aorta: Involvement of PAR-2, A Kawabata, R Kuroda, Y Nakaya, K Kawai, H Nishikawa, N Kawao, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 282, 2, 432, 435,   2001 03 , 10.1006/bbrc.2001.4597
    Summary:Protease-activated receptor-2 (PAR-2) and/or effector cell protease receptor-1 (EPR-1) may mediate the direct cellular actions of coagulation factor Xa in some cultured cell lines. The present study examined if factor Xa could actually evoke relaxation through either of these receptor systems in isolated rat aorta. Factor Xa at 8.5-85 nM, like the PAR-2-activators trypsin and SLIGRL-NH2, produced nitric oxide-dependent relaxation in the precontracted aortic rings. PAR-2 desensitization abolished relaxation responses to factor Xa as well as trypsin in the rings. The factor Xa interepidermal growth factor synthetic peptide (LFTRKL88)-F-83(G)-NH2, known to block factor Xa binding to EPR-1, failed to inhibit factor Xa-evoked relaxation in the preparations. Our findings provide evidence that factor Xa evokes relaxation by activating PAR-2, but independently of EPR-1, in the rat aorta. The factor Xa-PAR-2 pathway might thus contribute to the severe hypotension during sepsis, in which multiple coagulation factors including factor X would become activated and PAR-2 would be induced. (C) 2001 Academic Press.
  • Peripheral PAR-2 triggers thermal hyperalgesia and nociceptive responses in rats, A Kawabata, N Kawao, R Kuroda, A Tanaka, H Itoh, H Nishikawa, NEUROREPORT, 12, 4, 715, 719,   2001 03
    Summary:Protease-activated receptor-2 (PAR-2), a member of the G protein-coupled, seven trans-membrane domain receptor family, is activated by trypsin/tryptase and present in various tissues including the primary sensory neurons, playing a role in development of neurogenic inflammation. The present study examined if activation of peripheral PAR-2 could modulate nociception in the rat. Expression of mRNA for PAR-2 was confirmed in the L4-6 dorsal root ganglia, but not spinal cord. The PAR-2-activating peptide SLIGRL-NH2 administered by the intraplantar (i.pl.) route, produced thermal, but not mechanical, hyperalgesia in the rat, although the PAR-2-inactive control peptide LSIGRL-NH2 had no effect. Not only the PAR-2-activating but also inactive peptides elicited nociceptive behavior (licking/biting) in the intact rats, whereas only the former peptide produced such behavior in the rats that had received repeated administration of compound 48/80 for mast cell depletion. These data provide novel evidence that activation of peripheral PAR-2 is pro-nociceptive, producing thermal hyperalgesia and also triggering pain sensation, by itself, independently of mast cell degranulation. NeuroReport 12:715-719 (C) 2001 Lippincott Williams & Wilkins.
  • Specific distribution of sialic acids in animal tissues as examined by LC-ESI-MS after derivatization with 1, 2-diamino-4, t-methylenedioxybenzene., Anal. Chem., 73, 5422-5428,   2001 , 10.1021/ac0104328
  • In vivo evidence that protease-activated receptors 1 and 2 modulate gastrointestinal transit in the mouse., Br. J. Pharmacol., 133, 1213-1218,   2001 , 10.1038/sj.bjp.0704211
  • Lipopolysaccharide-induced subsensitivity of protease-activated receptor-2 in the mouse salivary glands in vivo., Naunyu-Schmiedeberg's Arch. Pharmacol., 364, 281-284,   2001 , 10.1007/s002100100449
  • ┣DBEx vivo(/)-┫DB evidence that the phosphodiesterase inhibitor IBMX attenuates the up-regulation of PAR-2 in the endotoxemic rat aorta., ┣DBThrombosis Research(/)-┫DB, 101, 513, 515,   2001 , 10.1016/S0049-3848(00)00425-4
  • Roles of urokinase type plasminogen activator in a brain stab wound, K Kataoka, T Asai, M Taneda, S Ueshima, O Matsuo, R Kuroda, A Kawabata, P Carmeliet, BRAIN RESEARCH, 887, 1, 187, 190,   2000 12 , 10.1016/S0006-8993(00)03042-0
    Summary:Urokinase type plasminogen activator (uPA) may influence brain pathophysiology after injury. We studied disruption of the blood-brain barrier (BBB) and changes in the vasculature after a brain stab wound in uPA-deficient, uPA receptor-deficient, and PA inhibitor-1 (PAI-1) deficient mice. The extravasation of immunoglobulin was greater in PAI-1 deficient mice; less pronounced in uPA-deficient mice; similar to controls in uPA receptor-deficient mice. Vasculatures in the wound proliferated in PAI-1 deficient mice. Our study shows that uPA affects BBB disruption. PA enhances angiogenesis after brain injury. (C) 2000 Elsevier Science B.V. All rights reserved.
  • Dual modulation by thrombin of the motility of rat oesophageal muscularis mucosae via two distinct protease-activated receptors (PARs): a novel role for PAR-4 as opposed to PAR-1, A Kawabata, R Kuroda, N Kuroki, H Nishikawa, K Kawai, BRITISH JOURNAL OF PHARMACOLOGY, 131, 3, 578, 584,   2000 10 , 10.1038/sj.bjp.0703590
    Summary:1 Since protease-activated receptors (PARs) are distributed throughout the gastrointestinal tract, we investigated the role of PARs In modulation of the motility of the rat oesophageal muscularis mucosae. 2 Thrombin produced contraction of segments of the upper and lower part of the smooth muscle. Trypsin contracted both the muscle preparations only at high concentrations. SFLLR-NH2 and TFLLR-NH2 (PAR-1-activating peptides), bur not the PAR-1-inactive peptide FSLLR-NH2, evoked a marked contraction. In contrast, the PAR-2 agonist SLIGRL-NH2 and the PAR-4 agonist GYPGKF-NH2 caused no or only a negligible contraction. the PAR-4 agonist 3 In oesophageal preparations precontracted with carbachol, thrombin produced a dual action i.e. relaxation followed by contraction. TFLLR-NH2 further contracted the precontracted preparations with no preceding relaxation. GYPGKF-NH2, but not the inactive peptide GAPGKF-NH2:, produced marked relaxation. Trypsin or SLIGRL-NH2 caused no relaxation. 4 The PAR-1-mediated contraction was completely abolished in Ca2+-free medium and considerably attenuated by nifedipine (1 mu M) and in a low Na- medium. The PAR-4-mediated relaxation was resistant to tetrodotoxin (10 mu M), apamin (0.1 mu M), charybdotoxin (0.1 mu M), L-N-G-nitroarginine methyl ester (100 mu M),, indomethacin (3 mu M), propranolol (5 mu M) or adenosine 3',5' cyclic monophosphorothioate, 8-bromo, Rp-isomer (30 mu M) 5 Thus, thrombin plays a dual role in modulating the motility of the oesophageal muscularis mucosae. producing contraction via PAR-I and relaxation ria PAR-4. The PAR-1-mediated effect appears to occur largely through increased Na- permeability followed by activation of L-type Ca2+ channels and subsequent influx of extracellular Ca2+ . Our data could provide evidence for a novel role of PAK-4 as opposed to PAR-1, although the underlying mechanisms are still open to question.
  • Characterization of the protease-activated receptor-1-mediated contraction and relaxation in the rat duodenal smooth muscle, A Kawabata, R Kuroda, N Kuroki, H Nishikawa, K Kawai, H Araki, LIFE SCIENCES, 67, 20, 2521, 2530,   2000 10 , 10.1016/S0024-3205(00)00835-3
    Summary:Activation of protease-activated receptor-1 (PAR-1) produces a dual action, apamin-sensitive relaxation followed by contraction, in the rat duodenal smooth muscle, which is partially dependent on activation of L-type Ca2+ channels, protein kinase C (PKC) or tyrosine kinase (TK), and resistant to tetrodotoxin. The present study further characterized the PAR-1-mediated duodenal responses. Removal of extracellular Ca2+ as well as SK&F96365 reduced the contraction due to the PAR-1 agonist TFLLR-NH2 (TFp-NH2) by 60-80% that was similar to the extent of the inhibition by nifedipine. Lowering of the extracellular Na2+ concentration, but not IAA-94, a Cl- channel inhibitor, reduced both the PAR-1-mediated contraction and relaxation by about 50%. U73122, a phospholipase C (PLC) inhibitor, or wortmannin, a phosphatidyl inositol S'-kinase (PI3K) inhibitor, significantly reduced the PAR-1-mediated contraction, but not the relaxation, by itself, as the PKC inhibitor GF109203X and the TK inhibitor genistein did. U73122 or wortmannin, like GF109203X, when applied in combination with genistein, significantly reduced the PAR-1-mediated relaxation. The relaxation was resistant to antagonists of PACAP receptors, VIP receptors and P-2 purinoceptors. Thus, the PAR-1-mediated contraction is considered to be dependent on intracellular and extracellular Ca2+, the influx of the latter being induced through activation of L-type Ca2+ channels triggered by the enhanced Na+ permeability, and that PLC and PI3K, in addition to PKC and TK, are involved in the PAR-1 mediated dual responses. Furthermore, non-adrenergic, non-cholinergic nerve neurotransmitter candidates that may modulate K+ channels do not appear to contribute to the relaxation by PAR-1 activation. (C) 2000 Elsevier Science Inc. All rights reserved.
  • Fluorometric determination of mucin-type glycoproteins by the galactose oxidase-peroxidase method, M Kinoshita, K Inagake, A Kawabata, R Kuroda, Y Oda, K Kakehi, ANALYTICAL BIOCHEMISTRY, 284, 1, 87, 92,   2000 08 , 10.1006/abio.2000.4689
    Summary:We developed a convenient and specific method for the determination of mucin-type glycoproteins using galactose oxidase and horseradish peroxidase on the basis of the contents of galactosyl and N-acetylgalactosaminyl residues in glycoproteins. Galactose and galactosamine residues released from glycoproteins after hydrolysis were oxidized with galactose oxidase and subsequently the resultant hydrogen peroxide was determined by a combination of horseradish peroxidase and 3-(p-hydroxyphenyl) propionic acid as a fluorogenic substrate, The contents of galactose/galactosamine residues in N- and O-glycans, as determined by the galactose oxidase-peroxidase method, were in good agreement with those described in the previous reports. We applied the present method to determine mucin-type glycoproteins secreted from rat gastric mucosa by stimulation with misoprostol, a prostaglandin E-1 analogue in vivo. Thus, the galactose oxidase-peroxidase: method is useful for the determination of mucin-type glycoproteins in biological materials. (C) 2000 Academic Press.
  • Determination of mucin in salivary glands using sialic acids as the marker by high-performance liquid chromatography with fluorometric detection, A Kawabata, N Morimoto, Y Oda, M Kinoshita, R Kuroda, K Kakehi, ANALYTICAL BIOCHEMISTRY, 283, 1, 119, 121,   2000 07 , 10.1006/abio.2000.4654
  • Activation of protease-activated receptor-2 (PAR-2) triggers mucin secretion in the rat sublingual gland, A Kawabata, N Morimoto, H Nishikawa, R Kuroda, Y Oda, K Kakehi, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 270, 1, 298, 302,   2000 04 , 10.1006/bbrc.2000.2404
    Summary:Protease-activated receptor-2 (PAR-2) is distributed throughout the gastrointestinal systems. The present study investigated the role for PAR-2 in the rat salivary glands. PAR-2 mRNA was detected in the sublingual, submaxillary, and parotid glands by a reverse-transcriptase polymerase chain reaction. In the isolated sublingual gland that exhibited the strongest signal for PAR-2, Ser-Leu-Ile-Gly-Arg-Leu-NH2, a PAR-2-activating peptide, and trypsin, a PAR-2-activating enzyme, but not thrombin that can activate PARs 1, 3, and 4, triggered secretion of N-acetylneuraminic acid, an indicator of mucin, that was a unique major sialic acid detectable after hydrolysis of the sublingual mucin with 0.1 N HCl. The PAR-2-mediated secretion of mucin was attenuated by genistein, a tyrosine kinase inhibitor, but not by inhibitors of protein kinase C and phosphatidyl inositol 3'-kinase. Thus, PAR-2 is expressed by the three distinct salivary glands in the rat, and sublingual PAR-2 appears to play a role in triggering mucin secretion, at least in part, via activation of tyrosine kinase. (C) 2000 Academic Press.
  • Protease-activated receptor (PAR), a novel family of G protein-coupled seven trans-membrane domain receptors: Activation mechanisms and physiological roles, A Kawabata, R Kuroda, JAPANESE JOURNAL OF PHARMACOLOGY, 82, 3, 171, 174,   2000 03 , 10.1254/jjp.82.171
    Summary:The protease-activated receptor (PAR) belongs to the large superfamily of G-protein-coupled seven trans-membrane domain receptors. The activation of PARs is achieved by proteolytic unmasking of the cryptic N-terminal receptor-activating sequence that binds to the body of the same receptor molecule. PARs-1, -3 and -4 are activated by thrombin, while PAR-2 is activated by trypsin or mast cell tryptase, but not by thrombin. PARs are widely distributed to a variety of tissues and participate in a number of physiological or pathophysiological phenomena such as platelet aggregation, inflammation and cardiovascular, digestive or respiratory functions. Thus, PARs are of physiological importance and also of pharmacological interest as the novel target for drug development.
  • Proteinase-activated receptor-2 (PAR-2) : regulation of salivary and pancreatic exocrine secretion in vivo in rats and mice., British Journal of Pharmacology, 129, 1627, 1632,   2000
  • Somatosensory cortex stimulation-evoked analgesia : potentiation by NO synthase inhibition., Life Sciences, 66, 20, PL271, PL276,   2000 , 10.1016/S0024-3205(00)00525-7
  • Guinea pig platelets do not respond to GYPGKF, a protease-activated receptor-4-activating peptide: a property distinct from human platelets, H Nishikawa, A Kawabata, K Kawai, R Kuroda, BLOOD COAGULATION & FIBRINOLYSIS, 11, 1, 111, 113,   2000 01
  • Characterization of protease-activated receptors in rat peritoneal mast cells, H Nishikawa, A Kawabata, R Kuroda, M Nishida, K Kawai, JAPANESE JOURNAL OF PHARMACOLOGY, 82, 1, 74, 77,   2000 01 , 10.1254/jjp.82.74
    Summary:Activation of protease-activated receptor (PAR)-1 or PAR-2 elicits inflammation most probably via mast cell degranulation in vivo. The present study aimed at characterizing PARs in rat peritoneal mast cells (PMC). Messenger RNA for PAR-I, but not for PAR-2, was detected in PMC. Thrombin, the PAR-I agonist SFLLR-NH2 or the PAR-2 agonist SLIGRL-NH2 failed to induce histamine release from PMC. Surprisingly, the PAR-2-inactive control peptide LSIGRL-NH2 triggered histamine release from PMC. Thus, PAR-1, but not PAR-2, are expressed in PRIG, whereas neither PAR-I nor PAR-2 are considered to be involved in degranulation of PRIG. LSIGRL-NH2 does not appear to be appropriate as a control peptide for PAR-2 in inflammation studies.
  • Proteinase activated receptor 2: role of extracellular loop 2 for ligand-mediated activation, B Al-Ani, M Saifeddine, A Kawabata, MD Hollenberg, BRITISH JOURNAL OF PHARMACOLOGY, 128, 5, 1105, 1113,   1999 11 , 10.1038/sj.bjp.0702834
    Summary:1 Rat proteinase-activated receptor-2 (PAR(2)) variants were stably expressed in rat KNRK cells: (a) wild-type (wt)-PAR(2); (b) PAR(2)PRR, with the extracellular loop 2 (EL-2) sequence P231E232E233-mutated to PRR and (c) PAR(2)NET, with the EL-2 sequence, PEEV changed to NETL. Cell lines were evaluated for their sensitivity (calcium signalling) towards trypsin and the receptor-activating peptides, SLIGRL-NH2, SLIGEL-NH2, trans-cinnamoyl(tc)-LIGRLO-NH2, and SFLLR-NH2. 2 SLIGEL-NH2 exhibited low potency (1 : 200 relative to SLIGRL-NH2) in wild-type PAR(2). Its activity was increased 5 fold in PAR(2)PRR, but it was inactive in PAR(2)NET. 3 In PAR(2)PRR, the potencies of SLIGRL-NH2, tc-LIGRLO-NH2, and SFLLR-NH2 were decreased by 80-100 fold. But, the potency of trypsin was decreased by only 7 fold. 4 In PAR(2)NET highly homologous in EL-2 with proteinase-activated receptor-1 (PAR(1)), the potency of the PAR(1)-derived peptide, SFLLR-NH2, was reduced by 100 fold compared with wt-PAR, whereas the potency of the PAR(2)-derived AP, SLIGRL-NH2 was reduced 10 fold. In contrast, the potency of trypsin in PAR(2)NET was almost the same as in wt-PAR(2). 5 We conclude that the acidic EL-2 tripeptide, PEE, in PAR(2) plays an important role in governing agonist activity. 6 The data obtained with the PEEV-->NETL mutation suggested: (a) that SLIGRL-NH2 and SFLLR-NH2 interact in a distinct manner with PAR(2) and (b) that SFLLR-NH2 may interact differently with PAR(2) than it does with PAR(1). 7 The differential reductions in the potencies of SLIGRL-NH2, compared with trypsin in the PAR(2)PRR and PAR(2)NET cell lines point to differences between the interactions of the trypsin-revealed tethered ligand and the free receptor-activating peptide with PAR(2).
  • Modulation by protease-activated receptors of the rat duodenal motility in vitro: possible mechanisms underlying the evoked contraction and relaxation, A Kawabata, R Kuroda, H Nishikawa, K Kawai, BRITISH JOURNAL OF PHARMACOLOGY, 128, 4, 865, 872,   1999 10 , 10.1038/sj.bjp.0702755
    Summary:1 The present study examined effects of agonist enzymes and receptor-activating peptides for protease-activated receptors (PARs) on duodenal motility in the rat, and also investigated possible mechanisms underlying the evoked responses. 2 Thrombin at 0.03-0.1 mu M and the PAR-1-activating peptide SFLLR-NH2 at 3-100 mu M or TFLLR-NH2 at 10-50 mu M produced a dual action, relaxation followed by contraction of the duodenal longitudinal muscle. The PAR-2-activating peptide SLIGRL-NH2 at 10-100 mM elicited only small contraction. Trypsin at 0.08 mu M induced small contraction, or relaxation followed by contraction, depending on preparations. The PAR-4-activating peptide GYPGKF-NH2 at 1000 mu M exhibited no effect. 3 The contractile responses of the duodenal strips to TFLLR-NH2 and to SLIGRL-NH2 were partially attenuated by the L-type calcium channel blocker nifedipine (1 mu M), the protein kinase C inhibitor GF109203X (1 mu M) and the tyrosine kinase inhibitor genistein (15 mu M), but were resistant to indomethacin (3 mu M) and tetrodotoxin (1-10 mu M). 4 The relaxation of the preparations exerted by TFLLR-NH2 was unaffected by indomethacin (3 mu M), propranolol (5 mu M), N-G-nitro-L-arginine methyl ester (100 mu M) and tetrodotoxin (1-10 mu M). This relaxation was resistant to either GF109203X (1 mu M) or genistein (15 mu M), but was, remarkably, attenuated by combined application of these two kinase inhibitors. 5 Apamin (0.1 mu M), an inhibitor of calcium-activated, small-conductance potassium channels, but not charybdotoxin (0.1 mu M), completely abolished the PAR-1-mediated duodenal relaxation, and significantly enhanced the PAR-1-mediated contraction. 6 These findings demonstrate that PAR-I plays a dual role, suppression and facilitation of smooth muscle motility in the rat duodenum, while PAR-2 plays a minor excitatory role in the muscle, and that PAR-4 is not involved in the duodenal tension modulation. The results also suggest that the contractile responses to PAR-1 and PAR-2 activation are mediated, in part, by activation of L-type calcium channels, protein kinase C and tyrosine kinase, and that the relaxation response to PAR-I activation occurs via activation of apamin-sensitive, but charybdotoxin-insensitive, potassium channels, in which both protein kinase C and tyrosine kinase might be involved synergistically.
  • Proteinase-activated receptor 2 (PAR(2)): Development of a ligand-binding assay correlating with activation of PAR(2) by PAR(1)- and PAR(2)-derived peptide ligands, B Al-Ani, M Saifeddine, A Kawabata, B Renaux, S Mokashi, MD Hollenberg, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 290, 2, 753, 760,   1999 08
    Summary:A cloned rat proteinase-activated receptor (PAR)(2)-expressing cell line (KNRK-rPAR(2)) was used to study the structure-activity relationships (elevated intracellular Ca2+) for a series of: 1) PAR(1)-derived receptor-activating ligands (PAR(1)-APs) [SFLLR (P5), SFLLR-NH2 (P5-NH2), SFLLRNP (P7), SFLLRNP-NH2 (P7-NH2), and TFLLR-NH2 (TF-NH2)] and 2) PAR(2)-derived-activating-peptides (PAR(2)-APs) [SLIGRL-NH2 (SL-NH2), SLIGR-NH2 (GR-NH2), and SLIGKV-NH2 (KV-NH2)]. The activities of the PAR-APs were compared with the PAR(2)-AP analog trans-cinnamoyl-Leu-Ile-Gly-Arg-Leu-Orn-NH2 tc-NH2), which as a [H-3]propionyl derivative ([H-3]propionyl-tc-NH2) was used to develop a radioligand-binding assay for PAR(2). The relative potencies of the PAR-APs in the Ca2+-signaling assay were tc-NH2 = SL-NH2 > KV-NH2 congruent to P5-NH2 > GR-NH2 > P7-NH2 > P7 > P5 > TF-NH2. The reverse sequence PAR-APs, LSIGRL-NH2 (LS-NH2), LRGILS-NH2 (LR-NH2), FSLLRY-NH2 (FSY-NH2), and FSLLR-NH2 (FS-NH2), as well as the Xenopus PAR(1)-AP TFRIFD-NH2, were inactive. The relative biological potencies of the peptides were in accord with their ability to compete for the binding of [H-3]propionyl-tc-NH2 (tc-NH2 = SL-NH2 > GR-NH2 congruent to P5-NH2 > P5) to KNRK-rPAR(2) cells, whereas inactive peptides (FS-NH2; LR-NH2) showed no appreciable binding competition. Our data therefore validate a ligand-binding assay for the use in studies of PAR(2) and indicate that the relative biological potencies of the PAR(1)-APs for activating rat PAR(2) parallel their ability to activate human PAR(1). The relative receptor-binding activities of the PAR-APs, although in general agreement with their relative biological activities, point to differences in the intrinsic receptor-activating activities between the several PAR-APs. The binding assay we have developed should prove of use for the further study of PAR(2)-ligand interactions.
  • Enhancement of vascular permeability by specific activation of protease-activated receptor-1 in rat hindpaw: a protective role of endogenous and exogenous nitric oxide, A Kawabata, R Kuroda, H Nishikawa, T Asai, K Kataoka, M Taneda, BRITISH JOURNAL OF PHARMACOLOGY, 126, 8, 1856, 1862,   1999 04 , 10.1038/sj.bjp.0702513
    Summary:1 To clarify the role of the first thrombin receptor protease-activated receptor (PAR)-1 in an inflammatory process, we tested and characterized the effect of intraplantar (i.pl.) administration of the highly specific PAR-1 agonist TFLLR-NH2 in rat hindpaw. 2 TFLLR-NH2 administered i.pl. at 0.01-0.03 mu mol per paw enhanced vascular permeability in the hindpaw and produced paw oedema in a dose-dependent manner, This effect was almost completely abolished by repeated pretreatment with compound 48, 80 to deplete inflammatory mediators in mast cells. 3 The NO synthase inhibitor N-G-nitro-L-arginine methyl ester or N-iminoethyl-L-ornithine. preadministered i.pl., stereospecifically potentiated the i.pl. TFLLR-NH2-induced permeability increase, while the NO donor sodium nitroprusside or KOC-18, given i.pl., suppressed the effect of TFLLR-NH2. 4 These findings demonstrate that specific activation of PAR-1 produces increased vascular permeability accompanied by oedema formation in the rat hindpaw. predominantly via mast cell degranulation, and that endogenous and exogenous NO plays a protective role in the PAR-1-mediated inflammatory event.
  • Evaluation of proteinase-activated receptor-1 (PAR(1)) agonists and antagonists using a cultured cell receptor desensitization assay: Activation of PAR(2) by PAR(1)-targeted ligands, A Kawabata, M Saifeddine, B Al-Ani, L Leblond, MD Hollenberg, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 288, 1, 358, 370,   1999 01
    Summary:We developed a calcium signaling-based assay, using cultured human embryonic kidney cells (HEK), that evaluates simultaneously, the activation/desensitization or blockade of the proteinase-activated receptors, PAR(1) and PAR(2). Using this assay, we analyzed the actions of a number of previously described putative PAR(1)-targeted peptide agonists and antagonists. We found that most of the previously described PAR(1)-targeted agents can also activate/desensitize PAR(2), and most of these peptides can also activate a calcium signaling pathway in a target cell that possesses PAR(2) along with PAR(1). Furthermore, we used this assay to develop a PAR(1) receptor-activating probe [Ala-parafluoroPhe-Arg-Cha-Cit-Tyr-NH2 (Cit-NH2)], which displays a high degree of specificity for PAR(1) over PAR(2), and we used the assay to quantitate the ability of trypsin to disarm the activation of PAR(1) by thrombin. The abilities of the PAR(1)-targeted agents to desensitize or block PAR(1) in the HEK cell assay were compared with their activities in a human platelet aggregation assay. Our data illustrate the usefulness of the HEK cell assay for evaluating the PAR(1)/PAR(2) selectivity of PAR-activating agonists. The PAR(1)-selective agonist that we developed using the assay should prove useful for studying the effects of selectively activating PAR(1) in vivo.
  • Penetration of cisplatin into mouse brain by lipopolysaccharide, T Minami, J Okazaki, A Kawabata, R Kuroda, Y Okazaki, TOXICOLOGY, 130, 2-3, 107, 113,   1998 09 , 10.1016/S0300-483X(98)00103-6
    Summary:We investigated the penetration of cisplatin into the mouse cerebral cortex-rich region (CCR) induced by lipopolysaccharide (LPS). With the injection of cisplatin into mice 3 h after the LPS treatment, platinum was detected in the CCR during the 7 days after the injection, while platinum was not detected in the CCR of cisplatin-injected mice without LPS pretreatment and of mice simultaneous treated with cisplatin and LPS. The N-G-nitro-L-arginine methyl ester dose-dependently lowered the platinum level. A dose of 5 mg/kg of aminoguanidine reduced the increase in the platinum level of the LPS-treated mouse, and platinum was no longer detected at doses of 20 mg/kg in the aminoguanidine-injected group. At doses of 500 mg/kg aminoguanidine, however, no effect was seen on the platinum level of the CCR induced by LPS. Regarding indomethacin, the injection of 5 mg/kg resulted in a decrease in the platinum content of the CCR, but not undetectable level. These results suggest that LPS increases the penetration of cisplatin into the mouse brain, and platinum may be accumulated in the CCR. Nitric oxide and prostaglandins contribute to the penetration of platinum into the cerebral cortex. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.
  • Importance of clinical activities to job satisfaction in Japanese pharmacists, A Kawabata, E Murakami, M Iwaki, T Ogiso, S Suzuki, M Mishima, M Takada, K Kakehi, AMERICAN JOURNAL OF HEALTH-SYSTEM PHARMACY, 55, 4, 360, 363,   1998 02
  • Increased vascular permeability by a specific agonist of protease-activated receptor-2 in rat hindpaw., Br. J. Pharmacol., 125, 3, 419, 422,   1998 , 10.1038/sj.bjp.0702063
  • Cross tolerance to environmental stress and endotoxin., Life Sci., 62, 21, PL327, PL333,   1998 , 10.1016/S0024-3205(98)00169-6
  • Roles of nitric oxide and prostaglandins in the increased permeability of the blood-brain barrier caused by lipopolysaccharide, Environ. Toxicol. Pharmacol., 5, 1, 35, 41,   1998 , 10.1016/S1382-6689(97)10004-7
  • Proteinase-activated receptors: structural requirements for activity, receptor cross-reactivity, and receptor selectivity of receptor-activating peptides, MD Hollenberg, M Saifeddine, B AlAni, A Kawabata, CANADIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY, 75, 7, 832, 841,   1997 07 , 10.1139/cjpp-75-7-832
    Summary:We have used three distinct bioassay systems (rat aorta (RA) relaxation; rat gastric longitudinal muscle (LM) contraction; human embryonic kidney 293 (HEK293) cell calcium signal) to evaluate the activity and receptor selectivity of analogues of the receptor-activating peptides derived either from the thrombin receptor (TRAPs, based on the human receptor sequence, SFLLRNPNDK...) or the proteinase-activated receptor 2 (PAR(2)APs, based on the rat receptor sequence SLIGRL...). Our main focus was on the activation of PAR(2) by PAR(2)APs and the cross-activation of PAR(2) by the TRAPs. In the RA and LM assay systems, PAR(2)APs that were either N-acetylated (N-acetyl-SLIGRL-NH2) or had a reverse N-terminal sequence (LSIGRL-NH2) were inactive, either as agonists or antagonists. An alanine substitution at position 3 of the PAR,AP (SLAGRL-NH2) led to a dramatic reduction of biological activity, as did substitution of threonine for serine at position 1 (TLIGRL-NH2). However, alanine substitution at PAR(2)AP position 4 caused only a modest reduction in activity, resulting in a peptide (SLIARL-NH2) with a potency equivalent to that of the human PAR(2)AP, SLIGKV-NH2. The order of potency of the PAR(2)APs in the RA, LM, and HEK assay systems was SLIGRL-NH2 > SLIARL-NH2>SLIGKV-NH2>TLIGRL-NH2> SLAGRL-NH2. In HEK cells, none of the PAR(2)APs activated the thrombin receptor (PAR(1)). However, in the HEK cell assay, the TRAP, SFLLR-NH2, activated or desensitized both PAR(1) and PAR(2) receptors, whereas the xenopus TRAP, TFRIFD-NH2, activated or desensitized selectively PAR(1) but not PAR(2). By constructing human-xenopus hybrid peptides, we found that the TRAPs, TFLLR-NH2, and SFLLFD-NH2 selectively activated the thrombin receptor in HEK cells without activating or desensitizing PAR(2). In contrast, the TRAPs SFLLRD-NH2 and AFLLR-NH2 activated or desensitized both PAR(1) and PAR(2). The order of potency for the TRAPs in all bioassay systems was SFLLR-NH2 similar or equal to SFLLRD-NH2 similar or equal to TFLLR-NH2 > SFLLFD-NH2, TFRIFD-NH2. We conclude that the N-terminal domain of the PAR(2)AP as well as positon 3 plays important roles for PAR, activation. Ln contrast, the first and fifth amino acids in the TRAP motif, SFLLR-NH,, do not play a unique role in activating the thrombin receptor, but if appropriately modified can abrogate the ability of this peptide to cross-desensitize or activate PAR(2), so as to be selective for PAR(1). The PAR(1)- and PAR(2)-selective peptides that we have synthesized will be of use for the evaluation of the roles after PAR(1) and PAR(2) receptor systems in vivo.
  • Protease-activated receptors : development of agonists selective for receptors triggered by either thrombin(PAR1)or trypsin(PAR2)., Proc. West. Pharmacol. Soc., 40, 49, 51,   1997
  • Lipopolysaccharide-induced platinum accumulation in the cerebral cortex after cisplatin administration in mice: Involvement of free radicals, T Minami, J Okazaki, A Kawabata, H Kawaki, Y Okazaki, ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY, 2, 4, 321, 326,   1996 12 , 10.1016/S1382-6689(96)00064-6
    Summary:The relationship between the accumulation of platinum in the cerebral cortex following cisplatin administration and injury to the blood-brain barrier after lipopolysaccharide (LPS) treatment was investigated. The appearance of intravenously injected fluorescein in the brain was significantly increased 10-24 h after LPS treatment, the effect being dose-dependent. Platinum was detectable in the cerebral cortex of cisplatin-treated mice 24 h after LPS treatment, but not without LPS treatment. In mice pretreated with alpha-tocopherol, LPS administration did not significantly augment fluorescein penetration into the brain, whereas pretreatment with either allopurinol or ascorbic acid did not modify the LPS-induced increase in fluorescein penetration. In contrast, platinum in the cerebral cortex after cisplatin administration was still detectable in the allopurinol-, ascorbic acid-, and alpha-tocopherol-pretreated groups, and the levels of platinum in these groups were not significantly different from those in the group treated with LPS only. Administration of superoxide dismutase (SOD), but not of catalase, tended to inhibit the penetration of fluorescein. Both SOD and catalase significantly lowered platinum content in the cerebral cortex following cisplatin administration in mice treated with LPS. Thus, free radicals may injure the blood-brain barrier in mice challenged with LPS, and allow cisplatin to penetrate into the cerebral cortex, resulting in platinum accumulation.
  • Attenuation by prolonged nitric oxide synthase inhibition of the enhancement of fibrinolysis caused by environmental stress in the rat, A Kawabata, T Hata, BRITISH JOURNAL OF PHARMACOLOGY, 119, 2, 346, 350,   1996 09 , 10.1111/j.1476-5381.1996.tb15992.x
    Summary:1 Nitric oxide (NO) suppresses platelet aggregation and plasminogen activator inhibitor (PAT) release from platelets, playing physiological and/or pathological roles in the haemostatic system. We investigated the effect of N-G-nitro-L-arginine methyl ester (L-NAME), an NO synthase inhibitor, on the disseminated intravascular coagulation (DIC)-like phenomena in rats under environmental stress, induced by prolonged fluctuation in air temperature, known as SART (specific alternation of rhythm in temperature) stress. 2 Exposure of rats to SART stress for 7 days caused mild DIC-like symptoms such as thrombocytopenia, hypofibrinogenemia, decreased factor VIII: coagulant activity and shortened euglobulin clot lysis time (ECLT). The enhanced fibrinolysis was accompanied by a marked decrease in the activity of plasma PAI. 3 L-NAME, but not its D-enantiomer, when administered orally at 0.3-10 mg kg(-1), twice a day for 7-day exposure to stress, inhibited the stress-induced decrease in fibrinogen levels in a dose-dependent manner, whereas it failed to alter platelet count, factor VIII:coagulant activity and plasma protein levels in stressed rats. All these parameters in unstressed rats were resistant to L-NAME at 10 mg kg(-1). 4 Repeated treatment with 10 mg kg(-1) of L-NAME blocked the shortening of ECLT and the decrease in PAT activity following stress exposure, although it was without effect in unstressed rats. 5 The inhibitory effects of L-NAME at 10 mg kg(-1) on the stress-induced alterations in fibrinogen levels and in ECLT were significantly reduced by coadministered L-arginine at 1000 mg kg(-1). 6 These findings demonstrate that repeated administration of L-NAME attenuates the enhanced fibrinolysis, without aggravating thrombocytopenia, in SART-stressed rats. Endogenous NO appears to contribute to the stress-induced development of fibrinolysis by suppressing plasma PAI activity, most probably as a result of inhibition of the PAI release from platelets.
  • 1H-[1,2,4]oxadiazolo[4,3-A]quinoxalin-1-one reverses the inhibition by sodium nitroprusside of thrombin-induced platelet aggregation in the rat, A Kawabata, THROMBOSIS RESEARCH, 82, 6, 543, 545,   1996 06 , 10.1016/0049-3848(96)00104-1
  • Kyotorphin synthetase activity in rat adrenal glands and spinal cord, A Kawabata, H Muguruma, M Tanaka, H Takagi, PEPTIDES, 17, 3, 407, 411,   1996 , 10.1016/0196-9781(96)00026-5
    Summary:Kyotorphin, an endogenous [Met(5)]enkephalin-releasing antinociceptive dipeptide (L-Tyr-L-Arg), is formed by kyotorphin synthetase from its constituent amino acids, L-Tyr and L-Arg, in the brain in an ATP-Mg2+-dependent manner. To elucidate the physiological role of kyotorphin in organs other than the brain, we examined the activity of kyotorphin synthetase in the rat adrenal glands and spinal cord. By Sephacryl S-300 gel-filtration chromatography of the soluble extracts from both the organs, the enzyme activity forming immunoreactive kyotorphin from L-Tyr and L-Arg in the presence of ATP and MgCl2 was detected in the fractions with the molecular mass of 200-300 kDa, being drastically reduced by the omission of ATP and MgCl2 from the reaction medium. The K-m values of the partially purified adrenal and spinal kyotorphin synthetase for L-Tyr, L-Arg, ATP, and MgCl2 were close to those of the brain enzyme. The activity of adrenal kyotorphin synthetase was inhibited by some L-Arg analogues, N-G-nitro-L-arginine methyl ester, alpha-methyl-L-ornithine and D-Arg, but not by N-G-nitro-L-arginine and N-iminoethyl-L-ornithine. In the crude soluble extracts from the adrenal glands and spinal cord, kyotorphin was formed by kyotorphin synthetase, and also by the enzymatic processing of the precursor proteins, in the presence of physiological concentrations of L-Tyr and L-Arg in addition to ATP and MgCl2. Thus, kyotorphin synthetase resembling that in the brain is present in the rat adrenal glands and spinal cord. The present findings may predict a functional role of the L-Arg-kyotorphin pathway in these organs.
  • Central antinociceptive effect of L-ornithine, a metabolite of L-arginine, in rats and mice, A Kawabata, K Iwatsubo, S Takaya, H Takagi, EUROPEAN JOURNAL OF PHARMACOLOGY, 296, 1, 23, 31,   1996 01 , 10.1016/0014-2999(95)00683-4
    Summary:L-Arginine produces central antinociception by acting as a precursor of kyotorphin (L-tyrosyl-L-arginine), a [Met(5)]enkephalin releaser. This study investigated the antinociceptive activity of L-ornithine, a metabolite of L-arginine. L-Ornithine given s.c. at 300-1000 mg/kg suppressed carrageenin-induced hyperalgesia in rats in a naloxone-reversible manner. L-Ornithine and L-arginine, when given i.c.v. at 10-100 mu g/mouse, elicited antinociception even in intact mice, the effects being abolished by naloxone or naltrindole, and potentiated by bestatin, an inhibitor of aminopeptidase and kyotorphinase. The antinociception induced by i.c.v. L-ornithine was also inhibited by i.c.v. L-leucyl-L-arginine, a kyotorphin receptor antagonist, but was resistant to intracisternal anti-kyotorphin serum. L-Tyrosyl-L-ornithine, a synthetic dipeptide, (1-10 mu g/mouse, i.c.v.), exerted kyotorphin-like antinociception in mice. These findings suggest that L-ornithine produces L-arginine-like antinociception via kyotorphin receptors. However, this effect does not appear to be mediated by kyotorphin itself, but most likely by L-tyrosyl-L-ornithine, a putative dipeptide.
  • Evidence that endogenous nitric oxide modulates plasma fibrinogen levels in mice., British Journal of Pharmacology, 117, 236, 237,   1996
  • Effect of aminoguanidine on the survival in mice treated with lipopolysaccharied., Pharmaceutical Sciences, 1, 455, 457,   1995
  • N-G-NITRO-L-ARGININE METHYL-ESTER AND ALPHA-METHYL-L-ORNITHINE INHIBIT KYOTORPHIN SYNTHETASE FROM RAT-BRAIN, A KAWABATA, M TANAKA, H MUGURUMA, H TAKAGI, PEPTIDES, 16, 7, 1317, 1319,   1995 , 10.1016/0196-9781(95)02017-Q
    Summary:Kyotorphin (KTP), an antinociceptive dipeptide (Tyr-Arg), is formed by KTP synthetase from L-Tyr and L-Arg in the brain. We examined the effects of various L-Arg analogues on immunoreactive KTP (iKTP) formation by KTP synthetase purified partially from rat brain. The NO synthase inhibitor N-G-nitro-L-arginine methyl ester (L-NAME), but not N-G-nitro-L-arginine and N-iminoethyl-L-ornithine, suppressed iKTP formation by KTP synthetase from 1 mM of L-Arg and L-Tyr, the IC50 value being 2.33 mM. Similarly, alpha-methyl-L-ornithine (alpha-MO) inhibited KTP synthetase, the IC50 value being 2.51 mM, D-Arg at high concentrations also exhibited a weak inhibitory effect. Kinetic experiments indicated that the inhibition by L-NAME and alpha-MO of KTP synthetase is competitive. Thus, these L-Arg analogues appear to act as the competitive inhibitor of KTP synthetase.
  • Supraspinally applied nitric oxide donors exert a dual action on thermal nociception in mice., Pharmaceutial Sciences, 1, 189, 192,   1995
  • COMPARISON OF ANTINOCICEPTION INDUCED BY SUPRASPINALLY ADMINISTERED L-ARGININE AND KYOTORPHIN, A KAWABATA, S MANABE, H TAKAGI, BRITISH JOURNAL OF PHARMACOLOGY, 112, 3, 817, 822,   1994 07
    Summary:1 Intracerebroventricular (i.c.v.) or intracisternal (i.cist.) administration of kyotorphin (KTP), an endogenous Met-enkephalin releaser, at 5 mu g per mouse, and L-arginine (L-Arg), a possible KTP precursor, at 30 mu g per mouse, elicited antinociception in mice to a similar extent, as assessed by the tail-flick test. 2 Intracisternal preadministration of anti-KTP serum abolished the effects of i.cist. KTP and i.c.v. or i.cist. L-Arg, but not of i.c.v. KTP. 3 The antinociceptive effects of i.cist. KTP and of i.c.v. or i.cist. L-Arg disappeared in reserpinized mice, whereas the effect of i.c.v. KTP was unaffected by treatment of mice with reserpine. 4 Intrathecal (i.t.) phentolamine markedly reduced the antinocieption induced by i.cist. KTP and by i.c.v. or i.cist. L-Arg, but not by i.c.v. KTP. 5 Intrathecal methysergide attenuated the antinociceptive effects of i.cist. KTP, but not of i.c.v. KTP and i.c.v. or i.cist. L-Arg. 6 These results suggest that the antinociception produced by i.cist. KTP, but not by i.c.v. KTP, is mediated by the brainstem-spinal noradrenergic and 5-hydroxytryptaminergic systems, and that L-Arg given i.c.v. or i.cist. increases KTP formation in the lower brain, possibly the brainstem, resulting in antinociception mediated by the descending noradrenergic system. Therefore, the regional distribution of KTP receptors and KTP synthetase in the brain does not appear to be common.
  • EFFECT OF TOPICAL ADMINISTRATION OF L-ARGININE ON FORMALIN-INDUCED NOCICEPTION IN THE MOUSE - A DUAL ROLE OF PERIPHERALLY FORMED NO IN PAIN MODULATION, A KAWABATA, S MANABE, Y MANABE, H TAKAGI, BRITISH JOURNAL OF PHARMACOLOGY, 112, 2, 547, 550,   1994 06 , 10.1111/j.1476-5381.1994.tb13108.x
    Summary:1 We investigated the effects of intraplantar (i.pl.) administration of L-arginine and NG-nitro-L-arginine methyl ester (L-NAME) on formalin-induced behavioural nociception in the mouse. 2 L- but not D-arginine, at 0.1-1 mu g per paw, coadministered with i.pl. formalin, enhanced the second- but not the first-phase nociceptive responses, whereas it was without significant effects at 3 mu g per paw, and conversely, produced antinociception at 10 mu g per paw, resulting in a bell-shaped dose-response curve. 3 L-NAME at 0.1-1 mu g per paw, when administered i.pl., exhibited antinociceptive activity in the second phase in a dose-dependent manner, although its D-enantiomer produced no effect. 4 An antinociceptive dose (I mu g per paw) of L-NAME (i.pl.) considerably reduced the increase in second-phase nociception elicited by low doses (1 mu g per paw) of i.pl. L-arginine. The second-phase nociception decrease induced by a large dose (10 mu g per paw) of i.pl. L-arginine was markedly reversed by i.pl. L-NAME at 0.1 mu g per paw, raising it to a level above that of the control (formalin only). 5 These results suggest that peripheral NO plays a dual role in nociceptive modulation, depending on the tissue level, inducing either nociceptive or antinociceptive responses.
  • THE NORADRENALINE PRECURSOR L-THREO-3,4-DIHYDROXYPHENYLSERINE EXHIBITS ANTINOCICEPTIVE ACTIVITY VIA CENTRAL ALPHA-ADRENOCEPTORS IN THE MOUSE, A KAWABATA, K KASAMATSU, N UMEDA, H TAKAGI, BRITISH JOURNAL OF PHARMACOLOGY, 111, 2, 503, 508,   1994 02 , 10.1111/j.1476-5381.1994.tb14765.x
    Summary:1 Systemic (s.c. or p.o.) administration of L-threo-3,4-dihydroxyphenylserine (droxidopa, L-threoDOPS; L-DOPS), a noradrenaline precursor, at a dose-range of 100-800 mg kg(-1), produced naloxone-resistant antinociception in a dose-dependent manner in the mouse, as assessed by the tail flick test, kaolin-induced writhing test and formalin-induced nociception test. 2 Antinociception elicited by L-DOPS (400mgkg(-1), s.c.) was not affected by s.c. injection of benserazide, a peripherally preferential L-aromatic amino acid decarboxylase inhibitor, but was suppressed by its intracerebroventricular (i.c.v.) injection. 3 I.c.v. or intrathecal (i.t.) administration of the non-selective alpha-blocker, phentolamine, significantly reduced L-DOPS-induced antinociception. 4 I.c.v. administration of the alpha(1)-blocker, prazosin, but not the alpha(2)-blocker, yohimbine, abolished the antinociceptive effects of L-DOPS. In contrast, both blockers, when administered i.t., exhibited significant inhibitory effects, 5 These results suggest that systemic L-DOPS produces opioid-independent antinociception, mediated by supraspinal alpha(1)-adrenoceptors and by spinal alpha 1- and alpha(2)-adrenoceptors and may predict additional therapeutic applications of L-DOPS as an analgesic.
  • NO and Pain(総説), Advances in Neurological Sciences (Shinkei Kenkyu no Shinpo), 38, 6, 940, 947,   1994 , 10.11477/mf.1431900594
  • Pharmacological studies on drugs for chronic pain which occurs often in old aged people. (Report II), Bulletin of Pharmaceutical Research and Technology Institute, 2, 61, 65,   1993
  • Possible involvement of oxygen-derived free radicals in abnormal hemostasis induced by SART stress (repeated cold stress) in laboratory animals., Thrombosis Research, 72,321-332,   1993
  • L-Arginine exerts a dual role in nociceptive processing in the brain : involvement of the kyotorphin-Met-enkephalin pathway and NO-cyclic GMP pathway., British Journal of Pharmacology, 109,73-79,   1993
  • CHARACTERIZATION OF PLATELET HYPOFUNCTIONS IN RATS UNDER SART STRESS (REPEATED COLD STRESS), A KAWABATA, T HATA, THROMBOSIS RESEARCH, 69, 2, 197, 207,   1993 01
    Summary:Platelet hypoaggregability has been reported in rats exposed to a chronic form of environmental stress induced by long-lasting fluctuation in air temperature, known as SART (specific alternation of rhythm in temperature) stress. This study examines functional characteristics of platelets from stressed rats in more detail. Exposure to stress reduced aggregation and ATP release in platelets stimulated with collagen, as determined using platelet-rich plasma (PRP). The resting levels of ATP but not ADP in platelets from stressed rats were lower than those from unstressed ones. Collagen-induced release and resting level of serotonin also decreased in platelets from stressed rats. In contrast, stress failed to cause hypoaggregability of washed platelets. Circulating platelet aggregates were detected in stressed rats. From these data, SART stress appears to cause intravascular activation of platelets in spite of in vitro hypofunctions. Alteration in plasma milieu may be associated with stress-induced platelet hypofunctions in PRP.
  • L-Tyrosine-induced antinociception in the mouse : involvement of central delta-opioid receptor and bulbo-spinal noradrenergic systems., European Journal of Pharmacology, 233,255-260,   1993
  • Platelet hypoaggregability in rats exposed to SART stress (repeated cold stress)., Thrombosis Research, 65,   1992
  • Antinociceptive effect of L-arginine on carrageenin-induced hyperalgesia in rats : possible involvement of central opioidergic systems., European Journal of Pharmacology, 218,   1992 , 10.1016/0014-2999(92)90159-2
  • L-Leucyl-L-arginine, naltrindole and D-arginine block antinociception elicited by L-arginine in mice with carrageenin-induced hyperalgesis., British Journal of Pharmacology, 107,   1992
  • CHANGES IN CNS LEVELS OF SEROTONIN AND ITS METABOLITE IN SART-STRESSED (REPEATEDLY COLD-STRESSED) RATS, T HATA, E ITOH, A KAWABATA, JAPANESE JOURNAL OF PHARMACOLOGY, 56, 1, 101, 104,   1991 05 , 10.1254/jjp.56.101
    Summary:Central nervous system levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in SART (specific alternation of rhythm in temperature)-stressed (repeatedly cold-stressed) rats were examined by HPLC-ECD. In SART-stressed rats, the levels of both 5-HT and 5-HIAA decreased in many brain areas. In the spinal cord, only the 5-HT level decreased. Therefore, the ratio of 5-HIAA to 5-HT increased only in the spinal cord. These results suggest that SART-stressed rats have some form of abnormality in the synthetic system of 5-HT.
  • Plasma catecholamine levels in SART-stressed rats and effects of drugs on stress-induced alteration in plasma and brain catecholamine levels, J. Autonomic Pharmacology, 11,   1991 , 10.1111/j.1474-8673.1991.tb00240.x
  • Blood coagulation and fibrinolysis in SART-stressed (repeated cold-stressed) rats and drug effect on the altered hemostatic parameters., Japanese J. Pharmacol., 56,   1991 , 10.1254/jjp.56.403
  • A CHARACTERISTIC PATTERN OF ACTIVE-AVOIDANCE BEHAVIOR IN SART-STRESSED RATS, T HATA, Y NISHIMURA, E ITOH, A KAWABATA, T KITA, JAPANESE JOURNAL OF PHARMACOLOGY, 49, 3, 436, 440,   1989 03 , 10.1254/jjp.49.436
  • SUBSENSITIVITY TO SUBSTANCE-P IN SART-STRESSED MICE, T HATA, E ITOH, R OYAMA, A KAWABATA, T KITA, JAPANESE JOURNAL OF PHARMACOLOGY, 49, 2, 293, 296,   1989 02 , 10.1254/jjp.49.293
  • IMPAIRMENT OF PASSIVE-AVOIDANCE PERFORMANCE IN SART-STRESSED MICE AND THE ACTION OF DRUGS, Y NISHIMURA, T HATA, A KAWABATA, E ITOH, T KITA, JAPANESE JOURNAL OF PHARMACOLOGY, 49, 1, 111, 117,   1989 01 , 10.1254/jjp.49.111
  • THE ABNORMAL OPEN-FIELD BEHAVIOR OF SART-STRESSED RATS AND EFFECTS OF SOME DRUGS ON IT, T HATA, Y NISHIMURA, T KITA, E ITOH, A KAWABATA, JAPANESE JOURNAL OF PHARMACOLOGY, 48, 4, 479, 490,   1988 12 , 10.1254/jjp.48.479
  • MECHANISM OF THE ANALGESIC EFFECT OF NEUROTROPIN, T HATA, T KITA, E ITOH, R OYAMA, A KAWABATA, JAPANESE JOURNAL OF PHARMACOLOGY, 48, 2, 165, 173,   1988 10 , 10.1254/jjp.48.165
  • CHANGES IN PLATELET COUNT AND RELATED PARAMETERS IN SART-STRESSED MICE AND THE ACTION OF ADMINISTERED NEUROTROPIN, T HATA, A KAWABATA, T KITA, E ITOH, Y NISHIMURA, JAPANESE JOURNAL OF PHARMACOLOGY, 47, 4, 349, 356,   1988 08 , 10.1254/jjp.47.349
  • THE RELATIONSHIP OF HYPERALGESIA IN SART (REPEATED COLD) STRESSED ANIMALS TO THE AUTONOMIC NERVOUS-SYSTEM, T HATA, T KITA, E ITOH, A KAWABATA, JOURNAL OF AUTONOMIC PHARMACOLOGY, 8, 1, 45, 52,   1988 03 , 10.1111/j.1474-8673.1988.tb00168.x
  • ELECTROCORTICOGRAM IN RATS LOADED WITH SART STRESS (REPEATED COLD STRESS), T HATA, Y NISHIMURA, T KITA, A KAWABATA, E ITOH, JAPANESE JOURNAL OF PHARMACOLOGY, 45, 3, 365, 372,   1987 11 , 10.1254/jjp.45.365
  • CATECHOLAMINE LEVELS IN THE BRAIN OF SART (REPEATED COLD)-STRESSED RATS, T HATA, T KITA, Y KAMANAKA, S HONDA, K KAKEHI, A KAWABATA, E ITOH, JOURNAL OF AUTONOMIC PHARMACOLOGY, 7, 3, 257, 266,   1987 09 , 10.1111/j.1474-8673.1987.tb00154.x
  • CHANGES OF TISSUE BLOOD-FLOW IN MICE LOADED WITH SART (REPEATED COLD) STRESS OR RESTRAINT AND WATER IMMERSION STRESS AND THE EFFECT OF ADMINISTERED NEUROTROPIN, T HATA, T KITA, A KAWABATA, E ITOH, Y NISHIMURA, JAPANESE JOURNAL OF PHARMACOLOGY, 41, 1, 69, 79,   1986 05 , 10.1254/jjp.41.69
  • On the hyperalgesia in SART-stressed mice, Neurosciences, 12, 2, 166, 167,   1986
  • Changes of total acetylcholine content and the activities of related enzymes in SART (repeated cold)-stressed rat brain and duodenum., Tomitaro KITA, Taeko HATA, Takashi HIGASHIGUCHI, Eiji ITOH, Atsufumi KAWABATA, Japanese Journal of Pharmacology, 40, 1, 174, 177,   1986 , 10.1254/jjp.40.174
  • Effect of ginseng-20S-prosapogenin on tissue blood flow measured by the hydrogen clearance method in sympathicotonic or parasympathicotonic-type stressed mice., TAEKO HATA, TOMITARO KITA, ATSUFUMI KAWABATA, EIJI ITOH, YUJI KAWASHIMA, J. Pharmacobio-Dyn., 8, 12, 1068, 1072,   1985 , 10.1248/bpb1978.8.1068

Research Grants & Projects

  • Study on protease-activated receptors
  • Study on pain modulation systems.