A growing body of evidence has demonstrated that microRNAs (miRs) have pivotal roles in the pathophysiological development mechanisms of diabetic cardiomyopathy (DCM). Previous studies have demonstrated that miR-186-5p was significantly decreased in DCM. In addition, it has recently been reported that an imbalance of miR-186 is associated with a variety of physiological and pathological processes. Therefore, the present study was designed to investigate the role of miR-186-5p in high glucose (HG)-induced cytotoxicity and apoptosis in AC16 cardiomyocytes. Reverse transcription-polymerase chain reaction was used to demonstrate the significant decrease in the level of miR-186-5p in HG-treated AC16 cells (P<0.05). Subsequently, it was clarified that pre-transfection with miR-186-5p mimic significantly ameliorated the effects of high glucose, which induced a significant decrease in the viability of AC16 cells (P<0.05) and increases in apoptosis, as evidenced by the appearance of apoptotic nucleus and the significant upregulation of apoptosis rate in AC16 cells (P<0.05). In addition, the significantly increased expression of caspase-3 induced by HG (P<0.01) was also reversed by miR-186-5p mimic (P<0.01). Conversely, transfection with miR-186-5p inhibitor significantly reduced the viability of AC16 cells (P<0.05) and promoted apoptosis (P<0.05) as well as the expression of caspase-3 in AC16 cells (P<0.01), indicating the beneficial role of miR-186-5p in the physiological process of HG-induced damage. In conclusion, these results suggest that the distribution of miR-186-5p contributes to HG-induced cytotoxicity and apoptosis in AC16 cardiomyocytes.
Keywords: AC16 cardiomyocytes; apoptosis; cardiomyocyte injury; high glucose; microRNA-186-5p.