[Overexpression of miRNA-130a-3p alleviates LPS-induced cardiomyocyte injury by regulating autophagy and apoptosis].

Objective: To investigate the effects of miRNA-130a-3p on autophagy and apoptosis induced by LPS in myocardial cells and its molecular mechanisms. Methods: H9C2 cells were divided into five groups: normal control group, LPS model group, miRNA negative control group miRNA-130a-3p mimics group(overexpression of miRNA-130a-3p) and miRNA-130a-3p mimics + LY294002 group(overexpression of miRNA-130a-3p + PI3K inhibitor). The LPS model group was induced by LPS at a final concentration of 10 μg/ml for 24 h. In the miRNA negative control group and miRNA-130a-3p mimics group, negative contro miRNA or miRNA-130a-3p mimics were transfected into H9C2 cells by lipo3000. After 24 h of culture, LPS was added into the medium for 24 hours. In the miRNA -130A-3P mimics + LY294002 group, miRNA -130A-3P mimics was transfected into H9C2 cells by using lipo3000, and LY294002 at a final concentration of 10 μmol/L was added to the culture medium for 24 h, followed by LPS at a concentration of 10 μg/ml for 24 h. The expression of miRNA-130a-3p mRNA in cells was detected by RT-qPCR. The CCK-8 assay was used to detect the cell viability. The contents of TNF-α, IL-6 and IL-1β were detected by ELISA assay. The contents of SOD and LDH in cell culture medium were detected by colorimetry. Western blot was used to detect the protein expressions of p-PI3K, p-AKT, Bax, Bcl-2, cleaved-caspase-3, LC3 and p62. Results: The results showed that the levels of miRNA-130a-3p mRNA, p-PI3K protein and p-AKT protein in LPS model cells were significantly lower than those in normal control group(P<0.01), and the expressions of p-PI3K, p-AKT protein in miRNA-130a-3p mimics group were increased significantly compared with LPS group(P<0.01,P<0.05). Compared with normal control group, the cell viability was decreased significantly and the contents of TNF-α, IL-6, IL-1β and LDH were increased significantly(P<0.01), the contents of SOD was decreased significantly in LPS group(P<0.01). The protein expression levels of Bax, cleaved-caspase-3 and p62 were increased significantly, while the expression level of Bcl-2 and LC3II/I ratio were decreased significantly in LPS group(P<0.01). miRNA-130a-3p mimics could increase the cell viability, decrease the contents of TNF-α, IL-6, IL-1β and LDH(P<0.01,P<0.05), increase the contents of SOD(P<0.05), decrease the expressions of Bax, cleaved caspase-3, p62(P<0.01), promote the expression of Bcl-2(P<0.01) and increase the ratio of LC3II/I(P<0.05). Compared with miRNA-130a-3p mimics group, LY294002 reversed the effects of miRNA-130a-3p mimics on cells. Conclusion: Overexpression miRNA-130a-3p could partly promote autophagy and inhibit cell apoptosis by activating PI3K/AKT signaling pathway to alleviate LPS-induced myocardial injury.