ASTRAGALOSIDE IV IMPROVED OXIDATIVE STRESS INDUCED INJURY THROUGH PINK1/PARKIN-MEDIATED MITOPHAGY IN H9C2 CELLS

Objective: To explore the mechanisms of Astragaloside IV on improving the oxidative stress induced injury in H9c2 cells. Design and method: H9c2 cells were divided into normal control group (cultured without intervention), H2O2 model group (cultured with 200umol/L H2O2 for 2 hours), As-IV with H2O2 group (pretreated with 100umol/L As-IV for 1 hour, then incubated with H2O2 for 2 hours) and Mdivi-1 with H2O2 group (pretreated with 5umol/L Mdivi-1 for 1 hour, then incubated with H2O2 for 2 hours). The activity of lactate dehydrogenase (LDH) in cell culture medium was measured to evaluate the degree of oxidative damage of cells, and the protein levels of Bax, Bcl-2, Drp1, LC3, PINK1 and Parkin in each group were detected by Western blot. The statistical analysis of the experimental results was carried out by SPSS13.0 software. Results: 1. Apoptosis of cells in each group: Compared with the normal control group, the expression of Bax in the H2O2 group increased (P<0.05), and the expression of Bcl-2 decreased [P<0.05]; compared with H2O2 group, the expression of Bax in As-IV group decreased (P<0.05), Bcl-2 The expression increased (P<0.05). 2. Oxidative stress damage of cells in each group: Compared with the normal control group, the LDH activity of cells in the H2O2 group increased, and compared with the H2O2 group Compared with that, the LDH activity of As-IV group decreased. 3. Mitochondrial dynamic expression: Compared with the normal control group, the expression of Drp1 in the H2O2 group increased; compared with the H2O2 group, the expression of Drp1 in the As-IV group and the Mdivi-1 group decreased. 4. The expression of mitophagy-related proteins in each group: Compared with the normal control group, the ratio of autophagy-related proteins LC3-II/LC3-I in the H2O2 group increased, and the expression of PINK1 increased (P<0.05), the expression of Parkin was significantly increased (P<0.05); compared with the H2O2 group, LC3-II/LC3-I in As-IV group and Mdivi-1 group decreased, the expression of PINK1 and Parkin proteins in As-IV group and Mdivi-1 group decreased . Conclusions: As-IV inhibited mitophagy through the PINK1/Parkin pathway, and alleviated oxidative stress induced injury in H9c2 cells.