title: Nitric oxide-induced oxidative stress impairs pacemaker function of murine interstitial cells of Cajal during inflammation.
abstract: The pacemaker function of interstitial cells of Cajal (ICC) is impaired during intestinal inflammation. The aim of this study is to clarify the pathophysiological mechanisms of ICC dysfunction during inflammatory condition by using intestinal cell clusters. Cell clusters were prepared from smooth muscle layer of murine jejunum and treated with interferon-gamma and lipopolysaccharide (IFN-γ+LPS) for 24h to induce inflammation. Pacemaker function of ICC was monitored by measuring cytosolic Ca(2+) oscillation in the presence of nifedipine. Treatment with IFN-γ+LPS impaired the pacemaker activity of ICC with increasing mRNA level of interleukin-1 beta, tumor necrosis factor-alpha and interleukin-6 in cell clusters; however, treatment with these cytokines individually had little effect on pacemaker activity of ICC. Treatment with IFN-γ+LPS also induced the expression of inducible nitric oxide synthase (iNOS) in smooth muscle cells and resident macrophages, but not in ICC. Pretreatment with NOS inhibitor, L-NAME or iNOS inhibitor, 1400W ameliorated IFN-γ+LPS-induced pacemaker dysfunction of ICC. Pretreatment with guanylate cyclase inhibitor, ODQ did not, but antioxidant, apocynin, to suppress NO-induced oxidative stress, significantly suppressed the impairment of ICC function induced by IFN-γ+LPS. Treatment with IFN-γ+LPS also decreased c-Kit-positive ICC, which was prevented by pretreatment with L-NAME. However, apoptotic ICC were not detected in IFN-γ+LPS-treated clusters, suggesting IFN-γ+LPS stimulation just changed the phenotype of ICC but not induced cell death. Moreover, ultrastructure of ICC was not disturbed by IFN-γ+LPS. In conclusion, ICC dysfunction during inflammation is induced by NO-induced oxidative stress rather than NO/cGMP signaling. NO-induced oxidative stress might be the main factor to induce phenotypic changes of ICC.
authors.affiliation: Department of Veterinary Pharmacology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kaji
authors.affiliation: Division of Anatomy and Neuroscience, Department of Morphological and Physiological Sciences, University of Fukui Faculty of Medical Sciences, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Horiguchi
authors.affiliation: Division of Anatomy and Neuroscience, Department of Morphological and Physiological Sciences, University of Fukui Faculty of Medical Sciences, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iino
authors.affiliation: Department of Cell Physiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Nakayama
authors.affiliation: Laboratory of Organic and Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Ohwada
authors.affiliation: Laboratory of Organic and Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Otani
authors.affiliation: Laboratory of Organic and Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.lastname: Firman
authors.affiliation: Department of Animal Radiology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Murata
authors.affiliation: Department of Physiology and Cell Biology, University of Nevada School of Medicine, 1664 North Virginia Street, Reno, NV 89557-0357, USA.
authors.forename: Kenton M
authors.initials: KM
authors.lastname: Sanders
authors.affiliation: Department of Veterinary Pharmacology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ozaki
authors.affiliation: Department of Veterinary Pharmacology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Electronic address: ahori@mail.ecc.u-tokyo.ac.jp.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hori
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000187:drug effects; D020013:Calcium Signaling; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004751:Enteritis / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D056885:Interstitial Cells of Cajal / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D007579:Jejunal Diseases / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology / Q000648:ultrastructure; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology / Q000648:ultrastructure; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000378:metabolism / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D016207:Cytokines; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D019009:Proto-Oncogene Proteins c-kit
keywords: Gastrointestinal motility; Interstitial cells of Cajal; Intestinal inflammation; Nitric oxide; Oxidative stress