miR-23a Regulates Cardiomyocyte Apoptosis by Targeting Manganese Superoxide Dismutase.

Cardiomyocyte apoptosis is initiated by various cellular insults and accumulated cardiomyocyte apoptosis leads to the pathogenesis of heart failure. Excessive reactive oxygen species (ROS) provoke apoptotic cascades. Manganese superoxide dismutase (MnSOD) is an important antioxidant enzyme that converts cellular ROS into harmless products. In this study, we demonstrate that MnSOD is down-regulated upon hydrogen peroxide treatment or ischemia/reperfusion (I/R) injury. Enhanced expression of MnSOD attenuates cardiomyocyte apoptosis and myocardial infarction induced by I/R injury. Further, we show that miR-23a directly regulates the expression of MnSOD. miR-23a regulates cardiomyocyte apoptosis by suppressing the expression of MnSOD. Our study reveals a novel model regulating cardiomyocyte apoptosis which is composed of miR-23a and MnSOD. Our study provides a new method to tackling apoptosis related cardiac diseases.