Original Article Trimetazidine protects against hypoxia-reperfusion-induced cardiomyocyte apoptosis by increasing microRNA-21 expression

Myocardial tissue injury caused by ischemia and hypoxia is a major cause of fatal diseases, including coro- nary atherosclerosis resulting from myocardial infarction and stroke. Trimetazidine (TMZ), as an anti-ischemic and antioxidant agent, has been demonstrated to preventing ischemia/reperfusion-induced cardiomyocyte apoptosis. However, the anti-apoptosis mechanism of TMZ has not been fully elucidated. The present study demonstrated that miR-21 involved trimetazidine-induced anti-apoptosis during H/R injury in H9C2 cell. In this study, TMZ increased miR-21 expression which further upregulated the Akt signaling activity via suppressing the expression of phospha- tase and tensin homolog (PTEN) in H/R H9C2 cell. The increased activity of Akt signaling decreased the ratio of Bax/ Bcl-2 and the expression of caspase-3 and inhibited H/R induced apoptosis. In conclusion, this study revealed the mechanism that TMZ up-regulated miR-21 expression, then miR-21 targeted PTEN increasing the PI3K pathway and finally the activation of this pathway counteracted the apoptotic effect of hypoxia/reperfusion.