MiR-377 accelerates cardiac hypertrophy by inhibiting autophagy via targeting PPARγ

Accumulating evidence suggests that cardiomyocyte autophagy is relevant to the onset of cardiac hypertrophy (CH). Several miRNAs are involved in the occurrence of heart failure, and relevant therapeutic treatments are currently being developed. MicroRNA-377 (miR-377) is known to correlate with the progression of various cancers, however, its function in CH has not been determined. Therefore, this study aimed to evaluate miR-377 expression in H2C9 hypertrophic cardiomyocytes in vitro and in a murine model of CH. Gene expression changes were verified via qRT-PCR. Western blotting was used for evaluation of alterations in the expression of signaling pathway-related proteins. Our results indicated that miR-377 expression was markedly upregulated in mice with hypertrophic cardiomyopathy. Autophagy markers were downregulated in these mice and in hypertrophic cardiomyocytes following miR-377 transfection. In addition, we demonstrated that miR-377 acts by targeting peroxisome proliferator-activated receptor gamma (PPAR gamma). PPAR gamma overexpression promoted autophagy and suppressed cyclosporine A-induced CH. In contrast, PPAR gamma knockdown further suppressed CH and autophagy. In conclusion, our findings indicated that miR-377 accelerates CH by inhibiting autophagy via targeting PPAR gamma. This newly identified miR-377/PPAR gamma axis improves our understanding of the molecular mechanisms underlying CH, and provides a potential new therapeutic target for its treatment.