title: Oxidative stress regulates collagen synthesis and matrix metalloproteinase activity in cardiac fibroblasts.
abstract: Oxidative stress has been implicated in the pathophysiology of myocardial failure. We tested the hypothesis that oxidative stress can regulate extracellular matrix in cardiac fibroblasts. Neonatal and adult rat cardiac fibroblasts in vitro were exposed to H(2)O(2) (0.05-5 microM) or the superoxide-generating system xanthine (500 microM) plus xanthine oxidase (0.001-0.1 mU/ml) (XXO) for 24 h. In-gel zymography demonstrated that H(2)O(2) and XXO each increased gelatinase activity corresponding to matrix metalloproteinases (MMP) MMP-13, MMP-2, and MMP-9. H(2)O(2) and XXO decreased collagen synthesis (collagenase-sensitive [(3)H]proline incorporation) without affecting total protein synthesis ([(3)H]leucine incorporation). H(2)O(2) and XXO decreased the expression of procollagen alpha(1)(I), alpha(2)(I), and alpha(1)(III) mRNA but increased the expression of fibronectin mRNA, suggesting a selective transcriptional effect on collagen synthesis. H(2)O(2), but not XXO, also decreased the expression of nonfibrillar procollagen alpha(1)(IV) and alpha(2)(IV) mRNA. To determine the role of endogenous antioxidant systems, cells were treated with the superoxide dismutase (SOD) inhibitor diethyldithiocarbamic acid (DDC, 100 microM) to increase intracellular superoxide or with the glucose-6-phosphate dehydrogenase inhibitor dehydroisoandrosterone 3-acetate (DHEA; 10 microM) to increase intracellular H(2)O(2). DDC and DHEA decreased collagen synthesis and increased MMP activity, and both effects were inhibited by an SOD/catalase mimetic. Thus increased oxidative stress activates MMPs and decreases fibrillar collagen synthesis in cardiac fibroblasts. Oxidative stress may play a role in the pathogenesis of myocardial remodeling by regulating the quantity and quality of extracellular matrix.
authors: Myocardial Biology Unit, Whitaker Cardiovascular Institute, Boston University School of Medicine, Massachusetts 02118, USA.
authors: D A
authors: DA
authors: Siwik
authors: P J
authors: PJ
authors: Pagano
authors: W S
authors: WS
authors: Colucci
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D009202:Cardiomyopathies / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis*; D003687:Dehydroepiandrosterone / Q000494:pharmacology; D004050:Ditiocarb / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D051379:Mice; D009206:Myocardium / Q000201:enzymology* / Q000648:ultrastructure; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000378:metabolism; D019820:Xanthine / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000494:pharmacology
chemical_list: D017382:Reactive Oxygen Species; D019820:Xanthine; D003687:Dehydroepiandrosterone; D003094:Collagen; D004050:Ditiocarb; D006861:Hydrogen Peroxide; D005954:Glucosephosphate Dehydrogenase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D020782:Matrix Metalloproteinases