ASCs-EVs Inhibit Apoptosis and Promote Myocardial Function in the Infarcted Heart via miR-221

Background: Extracellular vehicles (EVs) secreted from adipose-derived stem cells (ASCs) (ASCs-EVs) have the potential to treat myocardial infarction (MI), although the underlying mechanism remains unclear. The current study explored the ability of ASCs-EVs to inhibit apoptosis and promote myocardial function in the infarcted heart via microRNAs (miRNAs)-221. Methods: In hypoxia-induced H9C2 cells, a cardiac cell strain derived from the SD Rat left ventricle, we measured the cell viability and apoptosis-related protein expression after transfection with the ASCs-EVs-NC (negative control for EVs-miR-221) or ASCs-EVs-miR-221 mimics. We then verified the cardioprotective effects of miR-221-overexpressing ASCs-EVs by investigating myocardial cell apoptosis and cardiac function in a MI rat model treated with ASCs-EVs from miR-221-overexpressing ASCs by comparing control with ASC treatment. Results: The in vitro experiment results showed that the proliferation of H9C2 cells and the anti-apoptotic protein expression were significantly enhanced by the ASCs-EVs-miR-221 mimic. The in vivo experiment results found that ASCs-EVs from miR-221-overexpressing ASCs have cardioprotective effects, as demonstrated by lower serum troponin levels and left ventricular end-systolic volume, and a lower number of apoptotic myocardial cells than those in control and ASC-treated rats. Conclusions: ASCs-EVs have therapeutic effects on MI by inhibiting cardiomyocyte apoptosis via miR-221.