Background: Oxidative stress in cardiac myocytes is an important pathogenesis of diabetic cardiomyopathy (DCM). Previously, we reported that astragalus polysaccharide (APS) has protective effects against the oxidative stress of DCM. This study aimed to determine the effect of APS on the oxidative stress induced by hyperglycemia in H9C2 cells.
Methods: Rat H9C2 cells were cultured in vitro and randomly divided into the control group, HG group, APS-HG group, siRNASOD2 group, and APS-siRNASOD2 group. The cellular ultrastructure was measured by transmission electron microscopy. Cell apoptosis was examined by TUNEL staining. Levels of reactive oxygen species (ROS) were detected by a quantitative fluorescence assay (DHE). 8-OH-dG and nitrotyrosine, the indicators of oxidative stress injury, were detected by immunohistochemistry. A PCR array was used to evaluate the expression levels of 84 oxidative stress genes in cultured cells, and the PCR array results were partially verified by Western blot.
Results: APS treatment protected the H9C2 cell ultrastructure, reduced the level of cell apoptosis, inhibited cellular ROS production, and reduced the levels of oxidative stress injury indicators 8-OH-dG and nitrotyrosine in high glucose-induced or SOD2-silenced H9C2 cells. It also altered oxidative stress-related genes at the mRNA and protein levels.
Conclusion: APS may improve antioxidant capacity and inhibit oxidative stress injury in high glucose induced H9C2 cells.
Keywords: diabetic cardiomyopathy, cardiomyocyte, oxidative stress, ROS, PCR array, astragalus polysaccharide