MiR-210 protects cardiomyocytes from OGD/R injury by inhibiting E2F3

OBJECTIVE: To detect the change in miRNA-210 expression of cardiomyocytes under hypoxia/reoxygenation status. Also, the effect of miR-210 on the apoptosis of cardiomyocytes induced by oxygen-glucose deprivation/reperfusion (OGD/R) and its mechanism through establishing the OGD/R injury model of primary cardiomyocytes in this experiment were investigated. MATERIALS AND METHODS: The cell model of OGD/R injury was established. The cell apoptosis in each group was detected by methyl thiazolyl tetrazolium (MTT) assay and detection of Caspase-3 activity. The change in miR-210 expression in each group was detected by Real-time fluorescence quantitative polymerase chain reaction (PCR). The high-expression and low-expression miR-210 models were established through the transient transfection of miR-210 mimic and inhibitor to detect the relevant indexes of cell apoptosis. At the same time, changes in mRNA and protein expressions of E2F3 were detected by RTPCR and Western blotting, respectively. The E2F3 overexpression vector was constructed, and the overexpression vector plasmid and miR-210 mimic were jointly transfected into the cells to detect the relevant indexes of cell apoptosis. RESULTS: After OGD/R treatment, the activity of Caspase-3 was increased, the survival of cardiomyocytes was significantly inhibited and the expression level of miR-210 was up-regulated in OGD/R injury. Transfection of miR-210 mimic for miR-210 overexpression could alleviate the OG-D/R-induced cardiomyocyte injury, while the decrease of miR-210 expression could aggravate the apoptosis of cardiomyocytes. In addition, the high expression of miR-210 could inhibit the protein expression of E2F3, and co-transfection of E2F3 plasmid and miR-210 mimic could reverse the inhibiting effect of miR-210 on the apoptosis of cardiomyocytes. CONCLUSIONS: We confirmed that miR-210 can inhibit the OGD/R-induced apoptosis of cardiomyocytes, and miR-210, as an upstream factor, plays a protective role in cardiomyocytes through directly inhibiting the protein expression of its target gene E2F3.