LAUSR

OBJECTIVE To identify the expression changes of microRNA 93 (miR-93) in oxygen-glucose deprivation/reoxygenation (OGD/R) injury in cardiomyocytes and its mechanism of mediating OGD/R and inducing apoptosis. MATERIALS AND METHODS Primary cardiomyocytes were extracted and OGD/R model in cardiomyocytes was established in vitro. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expressions of miR-93, and Western blot assay was applied to measure the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and caspase-3. Flow cytometry was utilized to examine the cardiomyocyte apoptosis rate. RESULTS The apoptosis rate was increased after OGD/R in cardiomyocytes, accompanied by remarkable rise of miR-93 expression. After transfection of miR-93 antagomir, the apoptosis rate of cardiomyocyte induced by OGD/R was down-regulated, and the expression of cleaved caspase-3 was decreased. Meanwhile, the results of qRT-PCR and Western blot showed that the levels of Nrf2 mRNA and protein expression were up-regulated after the miR-93 level was inhibited, and luciferase reporter assay affirmed that Nrf2 was a target molecule for OGD/R-induced apoptosis mediated by miR-93. CONCLUSIONS miR-93 mediates OGD/R-induced hypoxia/reoxygenation injury apoptosis in cells by targeting Nrf2.