miR-30c-5p acts as a therapeutic target for ameliorating myocardial ischemia-reperfusion injury.

Coronary heart disease (CHD) is one of the most vital reasons for death and disability all over the world. miRNA, as a plasma index, is quite valuable for disease screening and prognosis prediction in CHD. Mining the molecular mechanism behind miRNA is also helpful for us to find molecular therapeutic strategies. In this research, we found that the expression of plasma miR-30c-5p in CHD patients was obviously lower than that in the control group (CG), which had a high differential value for CHD. We also discovered that miR-30c-5p was obviously correlated with clinical characteristics of CHD patients such as age, NYHA grade, smoking history, hypertension, hyperlipidemia, etc. In prognosis analysis, the miR-30c-5p expression in patients with poor prognosis was dramatically lower than that in those with good one, and the AUC for predicting poor prognosis of CHD was not lower than 0.850. In addition, we also induced myocardial ischemia/reperfusion (I/R) injury model of H9C2 cells through hypoxia/reoxygenation, and found that H9C2 cells also had abnormally down-regulated miR-30c-5p and up-regulated BCL2-like 11 (BCL2L11). Up-regulating miR-30c-5p or down-regulating BCL2L11 were helpful to improve proliferation and apoptosis of I/R injury model. Mechanically, BCL2L11 was also negatively regulated by miR-30c-5p, and up-regulating the former could cancel the in vitro protective effect of up-regulating the latter on H9C2 cell I/R injury model. In vivo research, up-regulating miR-30c-5p or down-regulating BCL2L11 can improve myocardial injury, histopathological changes and apoptosis in rat I/R model.