MiR-207 inhibits autophagy and promotes apoptosis of cardiomyocytes by directly targeting LAMP2 in type 2 diabetic cardiomyopathy

Abstract

Autophagy dysfunction plays a critical role in diabetic cardiomyopathy (DCM). MiR-207 regulates the expression of lysosomal-associated membrane protein 2 (LAMP2), an autophagy-related protein, following ischemic stroke in neurocytes. However, the roles and mechanisms of miR-207 in DCM remain unknown. Therefore, in this study, we aim to investigate the roles and mechanisms of miR-207 in type 2 DCM. The results showed that autophagic dysfunction with increased LC3II and P62 expression and decreased LAMP2 expression, and increased cell apoptosis with up-regulated cleaved-caspase3 expression were noted in the myocardium of type 2 DCM mice and neonatal mouse cardiac myocytes (NMCMs) stimulated with PA. In addition, miR-207 was significantly upregulated in the myocardium of DCM mice and NMCMs stimulated with PA. In NMCMs, miR-207 inhibited LAMP2 mRNA and protein expression. MiR-207 mimics significantly inhibited autophagy by increasing P62 and LC3II expression and promoted cell apoptosis by increasing cleaved-caspase3 expression, and these effects were reversed by LAMP2 overexpression. In conclusion, miR-207 inhibited autophagy and promoted apoptosis of cardiomyocytes by directly targeting LAMP2, which participated in the development of type 2 diabetic cardiomyopathy.

Keywords: Apoptosis; Autophagy; Diabetic cardiomyopathy; LAMP2; miR-207.