MicroRNA-221/222 Mediates ADSC-Exosome-Induced Cardioprotection Against Ischemia/Reperfusion by Targeting PUMA and ETS-1

Cardiovascular disease is a major health problem in industrialized and developing countries and is the leading cause of death and disability. Myocardial ischemia/reperfusion (I/R) causes cardiomyocyte damage such as apoptosis and hypertrophy. The purpose of this study was to investigate the effects of exosomes from adipose-derived stem cells (ADSC-Exo) on hearts from I/R mice and to explore the underlying mechanisms. ADSC-Exo significantly decreased I/R-induced cardiomyocyte apoptosis and hypertrophy, as detected by TdT-mediated dUTP nick end-labeling (TUNEL) and wheat germ agglutinin (WGA) staining, respectively. In addition, the expression of apoptosis-related proteins p-p53 and PUMA and hypertrophy-related proteins ETS-1 and ANP were significantly reduced in the cardiomyocytes of ADSC-Exo-treated I/R mice compared to those of control mice. Both PUMA and ETS-1 are reported to be target genes for miR-221/222. I/R operation significantly reduced miR-221/222 expression, while ADSC-Exo treatment increased miR-221/222 expression, as detected by RT-qPCR. We also observed that cardiac I/R operation markedly increased cell apoptosis and hypertrophy in miR-221/222 knockout (KO) mice, while ADSC-Exo reduced the effects of I/R operation. Furthermore, ADSC-Exo protected H9c2 cardiomyocytes from H2O2-induced damage by reducing apoptosis and hypertrophy in vitro. H2O2 treatment significantly reduced miR-221/222 expression, while ADSC-Exo treatment reversed this effect in H9c2 cells. ADSC-Exo treatment decreased H2O2-induced PUMA and ETS-1 expression. Compared with control treatment, I/R treatment significantly reduced p-AKT and increased p-p65, while ADSC-Exo and miR-221/222 mimics attenuated these effects. The AKT activator SC79 and p65 inhibitor Bay 11-7082 reduced H2O2-induced cell apoptosis and hypertrophy. Based on these findings, ADSC-Exo prevents cardiac I/R injury through the miR-221/miR-222/PUMA/ETS-1 pathway. Therefore, ADSC-Exo is an effective inhibitor of I/R-induced heart injury.