SIRT1,also named as SIR2L1,contains a deacetylase sirtuin-type domain and belongs to the sirtuin family. It regulates processes such as apoptosis and muscle differentiation by deacetylating key proteins. SIRT1 in particular initiates several signalling events relevant to cardioprotection,including: activation of endothelial nitric oxide synthase,insulin receptor signalling,and autophagy. In addition SIRT1 activation elicits resistance to oxidative stress via regulation of transcription factors and co-activators such as FOXO,Hif-2a,and NF-kB. SIRT1 regulates the p53-dependent DNA damage response pathway by binding to and deacetylating p53,specifically at Lysine 382.