RESUMO
AIMS: We previously demonstrated that resveratrol (RSV) administration causes cardiac stromal cell-derived factor (SDF)-1 upregulation and can enhance the mobilization of stem cells in mice with acute myocardial infarction (AMI). However, the upstream signal transduction involved in SDF-1 regulation in the setting of AMI and RSV administration remains unclear. Because RSV is a sirtuin 1 (SIRT1) activator and SIRT proteins act as deacetylases, we investigated the role of SIRT1 in SDF-1 upregulation and its subsequent effects. METHODS AND RESULTS: In vitro experiments with H9C2 cardiomyocytes under hypoxia and serum-deprivation conditions showed that p53 acted upstream of SDF-1. RSV could not regulate SDF-1 effectively after SIRT1 silencing, indicating that it is dependent on SIRT1. Subsequently, male C57BL/6 mice were divided into four groups: 1) sham, 2) MI, 3) MI+RSV, and 4) MI+RSV plus nicotinamide, an inhibitor of the deacetylase activity of SIRT (MI+RSV+NAM). Compared with the sham mice, AMI caused a slight increase in the cardiac p53 level and resulted in significant SIRT1 downregulation and p53 acetylation or activation. Compared with the MI mice, MI+RSV administration improved the cardiac SDF-1 level and reversed the reduction of SIRT1 and the activation of p53. Furthermore, we observed less cardiac dysfunction in MI+RSV mice and determined that NAM abolished the effects of RSV. CONCLUSIONS: RSV enhances cardiac SDF-1 excretion after AMI partially through a SIRT1 normalization/p53 inactivation pathway.
Assuntos
Quimiocina CXCL12/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Estilbenos/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Animais , Hipóxia Celular/efeitos dos fármacos , Fibrose , Inativação Gênica/efeitos dos fármacos , Testes de Função Cardíaca/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Resveratrol , Sirtuína 1/metabolismo , UltrassonografiaRESUMO
To reveal the involvement of oxidative stress in hypertension and insulin resistance. Angiotensin Ⅱ was given to adrenomedullin-knockout mice for 4 weeks. 4-Hydroxy-TEMPOL, a superoxide scavenger mimetic was also employed. The results suggested that adrenomedullin may exert a protective effect against insulin resistance via its intrinsic antioxidant effect.
