【Animal experiment】-miR-221 in H2O2-induced rat cardiomyocyte injury and its mechanism

  Objective: To investigate the role and mechanism of miR-221 in rat cardiomyocyte (H9c2) injury induced by hydrogen peroxide (H2O2).

  Method: MTT method detects the damaging effect of various concentrations of H2O2 on H9c2 cells, and RT-PCR method detects the expression of miR-221. MiR-221 inhibitor and negative control were transferred to H9c2 cardiomyocytes by Lipofectamine 2000, and the experiment was conducted in four groups: normal control group, model control group (H2O2 group), negative control group (H2O2 + negative control group) and normal Control group. Inhibition group (H2O2 + miR-221 inhibitor group). MTT method was used to detect cell viability, a pyridine orange staining to detect cell apoptosis, phosphatase deletion of Bax, Bcl-2 and chromosome 10, tenascin homologous gene protein (PTEN) and p protein kinase (AKT) Western blotting.

  Results: 0, 25, 50, 100, 200, 400μmol/LH2O2 gradually enhanced the inhibitory effect on H9c2 cell viability, while 200μmol/LH2O2 moderately inhibited cell viability. be used as. Compared with the normal control group, the expression of miR-221 in the model control group and the negative control group was significantly up-regulated (P\u003c0.01), and the viability of H9c2 cells decreased (P\u003c0.01). The apoptosis rate was significantly increased (P\u003c0.01), the expression of Bax and PTEN was up-regulated (P\u003c0.01), and the expression of Bcl-2 and p-AKT was down-regulated (P\u003c0.01). P\u003c0.01). Compared with the model control group and the negative control group, the expression of miR-221 in the inhibition group was significantly down-regulated (P\u003c0.01), and the viability of H9c2 cells increased (P\u003c0.01). , The cell apoptosis rate is greatly reduced (P\u003c0.01). The expression of PTEN was down-regulated (P\u003c0.01), and the expression of Bcl-2 and p-AKT was up-regulated (P\u003c0.01).

  Conclusion: The low expression of miR-221 can significantly inhibit H2O2-induced oxidative stress damage to H9c2 cardiomyocytes. It is related to the regulation of PTEN/AKT signaling pathway.