[Effect of miR-125a-5p targeting Scarb1 gene on hypoxia/reoxygenation injury of cardiomyocytes and its mechanism].

OBJECTIVE To explore the effect and mechanism of miR-125a-5p targeted regulation of scavenger receptor B1 (Scarb1) gene on anoxia/reoxygenation injury of rat cardiomyocytes. METHODS H9c2 rat cardiomyocytes were randomly divided into blank control group, hypoxia/reoxygenation group, transfection control group and mir-125a-5p transfection group. The expression of miR-125a-5p, cardiomyocyte viability, apoptosis rate, ATP content and the expression of Scarb1, Cyt C, Bax, Bcl-2 and NF-κB signaling pathway related proteins were determined. Target gene of miR-125a-5p was predicted with Targetscan software, and the targeting of miR-125a-5p on Scarb1 was verified by double luciferase reporter gene experiment. RESULTS Compared with the blank control group, the expression of miR-125a-5p, Bax, Cyt C and the apoptotic rate of cardiomyocytes in the hypoxia/reoxygenation group were significantly increased (P<0.05), while the expression of Scarb1, Bcl-2 and the content of ATP were significantly decreased (P<0.05). Compared with the control group, the situation of mir-125a-5p transfection group was just the opposite. Double luciferase reporter gene experiment has confirmed Scarb1 to be the target of miR-125a-5p. Hypoxia/reoxygenation can promote the expression of NF-κB p65, C-myc and Cyclin D1 in cardiomyocytes, while down-regulating the expression of miR-125a-5p can inhibit the expression of such proteins. CONCLUSION Hypoxia/reoxygenation can induce the expression of miR-125a-5p in rat cardiomyocytes. Inhibition of miR-125a-5p can protect cardiomyocytes from hypoxia/reoxygenation by up-regulating the expression of Scarb1. The mechanism may be related to the inhibition of activation of NF-κB signaling pathway.