SIRT1 and cardiovascular disorder: On the contrary, another in vivo study demonstrated that the overexpression of SIRT1 in endothelial cells displayed protective activity against the age-induced impairment of vasodilator responses and inhibited vasoconstrictor responses to acetylcholine, suggesting that boosting the endothelial expression of SIRT1 may represent a promising intervention for treatment of cardiovascular diseases [67].