stilbenes and Cardiomyopathy--Dilated

Oxidative stress plays a pivotal role in chronic heart failure. SIRT1, an NAD(+)-dependent histone/protein deacetylase, promotes cell survival under oxidative stress when it is expressed in the nucleus. However, adult cardiomyocytes predominantly express SIRT1 in the cytoplasm, and its function has not been elucidated. The purpose of this study was to investigate the functional role of SIRT1 in the heart and the potential use of SIRT1 in therapy for heart failure. We investigated the subcellular localization of SIRT1 in cardiomyocytes and its impact on cell survival. SIRT1 accumulated in the nucleus of cardiomyocytes in the failing hearts of TO-2 hamsters, postmyocardial infarction rats, and a dilated cardiomyopathy patient but not in control healthy hearts. Nuclear but not cytoplasmic SIRT1-induced manganese superoxide dismutase (Mn-SOD), which was further enhanced by resveratrol, and increased the resistance of C2C12 myoblasts to oxidative stress. Resveratrol's enhancement of Mn-SOD levels depended on the level of nuclear SIRT1, and it suppressed the cell death induced by antimycin A or angiotensin II. The cell-protective effects of nuclear SIRT1 or resveratrol were canceled by the Mn-SOD small interfering RNA or SIRT1 small interfering RNA. The oral administration of resveratrol to TO-2 hamsters increased Mn-SOD levels in cardiomyocytes, suppressed fibrosis, preserved cardiac function, and significantly improved survival. Thus, Mn-SOD induced by resveratrol via nuclear SIRT1 reduced oxidative stress and participated in cardiomyocyte protection. SIRT1 activators such as resveratrol could be novel therapeutic tools for the treatment of chronic heart failure.

Topics: Adult; Animals; Cardiomyopathy, Dilated; Cell Nucleus; Cell Survival; Cells, Cultured; Chronic Disease; Cricetinae; Disease Models, Animal; Enzyme Activation; Heart Failure; Humans; Male; Mesocricetus; Mice; Muscle Fibers, Skeletal; Myocardial Infarction; Myocytes, Cardiac; Oxidative Stress; Phenols; Plant Extracts; Rats; Resveratrol; Sirtuin 1; Stilbenes; Superoxide Dismutase

Myosin-induced autoimmune myocarditis of rats is a model of human dilated cardiomyopathy. Resveratrol is a natural polyphenol found in grapes and wine that is reported to have cardioprotective and immunomodulatory effects.. To examine the effect of resveratrol on myocarditis, vehicle or resveratrol (50 mg/kg per day) was administered to cardiac myosin immunized rats 1 day before the immunization. At 14 days after immunization, resveratrol had preserved cardiac function of myosin-immunized rats according to echocardiographic analysis. The heart weight/tibial length ratio of vehicle-treated myosin-immunized rats was increased by 1.8-fold compared with unimmunized rats, and resveratrol attenuated the heart weight increase. Resveratrol significantly decreased cellular infiltration, fibrosis, and expression of inflammatory cytokines in the myocardium. Expressions of antioxidant genes were increased in myosin-immunized hearts, and resveratrol decreased those expressions. Resveratrol also attenuated myocarditis 21 days after immunization. SIRT1, a potential effector of resveratrol, was increased in the myocardium of myosin-immunized rats compared with unimmunized rats. The SIRT1 protein was localized mainly in infiltrating mononuclear cells.. Resveratrol significantly ameliorated myocardial injury and preserved cardiac function in a rat model of autoimmune myocarditis. Resveratrol may be a therapeutic modality for myocarditis.

Topics: Animals; Autoimmune Diseases; Cardiomegaly; Cardiomyopathy, Dilated; Cardiotonic Agents; Chemotaxis, Leukocyte; Disease Models, Animal; Electrocardiography; Female; Inflammation; Leukocytes, Mononuclear; Myocarditis; Myosins; Rats; Rats, Inbred Lew; Resveratrol; Sirtuin 1; Sirtuins; Stilbenes