SIRT3 and cardiac hypertrophy: SIRT3 prevents cardiac hypertrophy through FoxO3 activation, with subsequent induction of MnSOD, resulting in reduced intracellular ROS concentration, thus suppressing ROS-induced mitogen-activated protein kinases which could otherwise directly promote hypertrophy, such as Ras and Akt/PI3K (Sundaresan et al., 2009).