title: Differential regulation of intracellular redox state by extracellular matrix proteins in glomerular mesangial cells: potential role in diabetic nephropathy.
abstract: Advanced diabetic nephropathy is characterized by abnormal synthesis of extracellular matrix (ECM) proteins, such as collagen I (COL I). The present experiments were designed to test the hypothesis that the presence of abnormal ECM proteins may be responsible for increased generation of reactive oxygen species (ROS) that are thought to have an important role in the pathogenesis of diabetic nephropathy. SV40 MES 13 murine mesangial cells were plated on COL I or collagen IV (COL IV) for 3 h at 5.5 or 25 mM D-glucose concentration. Increased intracellular ROS generation and reduced intracellular nitric oxide (NO) production was measured in cells attached to COL I compared with cells attached to COL IV. Treatment with N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME), an inhibitor of NO synthase, reduced this difference in ROS generation between cells attached to either COL I or IV. The results using antibodies against integrins also indicated that an alpha(2) integrin-mediated pathway was involved in the different response in ROS generation caused by ECM proteins. These results suggest that contact between altered ECM proteins that are present in advanced diabetic nephropathy and mesangial cells has the potential to increase intracellular oxidative stress, leading to progressive glomerular damage.
authors.affiliation: Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kamikyo-ku, Kyoto, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Nakajima
authors.forename: Goji
authors.initials: G
authors.lastname: Hasegawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Kamiuchi
authors.forename: Michiaki
authors.initials: M
authors.lastname: Fukui
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Masumi
authors.initials: M
authors.lastname: Tominaga
authors.forename: Mai
authors.initials: M
authors.lastname: Asano
authors.forename: Hiroko
authors.initials: H
authors.lastname: Hosoda
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Naoto
authors.initials: N
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D024042:Collagen Type I / Q000494:pharmacology; D024141:Collagen Type IV / Q000494:pharmacology; D003928:Diabetic Nephropathies / Q000378:metabolism* / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005109:Extracellular Matrix / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology; D016023:Integrins / Q000378:metabolism; D050527:Mesangial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D024042:Collagen Type I; D024141:Collagen Type IV; D016326:Extracellular Matrix Proteins; D016023:Integrins; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D005947:Glucose