MicroRNA-19b-1 reverses ischaemia-induced heart failure by inhibiting cardiomyocyte apoptosis and targeting Bcl2 l11/BIM.

Ischaemia induces cardiac apoptosis and leads to a loss of cardiac function and heart failure after myocardial infarction. MicroRNA-19b-1 (miR-19b-1), a key member of the miR-17/92 cluster, plays crucial roles in inhibiting apoptosis. However, the role of miR-19b-1 in ischaemia-induced heart failure remains unknown. In this study, ischaemia resulted in cardiac apoptosis and the suppression of miR-19b-1 expression, whereas miR-19b-1 overexpression inhibited ischaemia-induced cardiac apoptosis in vivo and in vitro. Moreover, miR-19b-1 not only attenuated the infarct size but also ameliorated heart failure after myocardial infarction, including the changes in the left ventricular ejection fraction and volume load. Mechanically, miR-19-1 targeted and downregulated the mRNA and protein expression of Bcl2l11/BIM, a pro-apoptotic gene of the Bcl-2 family. Together, these results revealed an essential role of miR-19b-1 in ischaemia-induced heart failure.