Simvastatin protects high glucose-induced H9c2 cells from injury by inducing autophagy

Abstract

Context Simvastatin is the first line therapeutic drug for coronary heart disease and atherosclerosis. The protective effect mechanism of simvastatin on cardiomyocytes is unclear. Objective This study explores the effect of simvastatin on high glucose induced cardiomyocyte injury and the role of autophagy during the process. Materials and methods H9c2 cells were incubated with different doses of glucose (0, 50, 100, 200 mM) for 24 h to verify the glucose induced injury. The H9c2 cells were pre-treated with simvastatin at different dosages (0, 0.1, 0.5, 1 μM) for 30 min to rescue the injury followed by the autophagy evaluation. 3-MA was used as an autophagy inhibitor to confirm the role of autophagy in simvastatin treated process. CCK-8 assay, FACS assay, confocal microscopy, western blotting and immunofluorescence analysis were conducted to evaluate the high glucose induced injury or protective effects of simvastatin in H9c2 cell line. Results High glucose dramatically decreased H9c2 cell viability (0 mM, 0.58 ± 0.09%; vs. 50 mM, 8.67 ± 0.43%; 100 mM, 16.1 ± 3.56%; 200 mM, 32.9 ± 2.63%), induced significant cell apoptosis (0 mM, 0.96 ± 0.16%, vs. 50 mM, 7.00 ± 0.63%; 100 mM, 12.9 ± 0.78%; 200 mM, 21.8 ± 1.17%) and suppressed cell autophagy. Simvastatin decreased apoptosis and attenuate injury by decreasing cell apoptosis ratio, elevating Bcl-2 expression while decreasing Bax and caspase-3 protein expressions. Meanwhile, simvastatin restored the autophagy depicted by western blotting with increased ATG-5, Beclin1 and LC3II/LC3I protein expression and decreased p62 expression, as well as immunofluorescence with elevated LC3 fluorescence density. Discussion and conclusions The myocardial protective effect mediated by autophagy activated by simvastatin to some extent elucidated the mechanism of the protective effect of simvastatin on H9c2 cell injury, which provided a certain theoretical basis for the clinical application of simvastatin in the treatment of cardiovascular diseases. In addition, we speculate that simvastatin may be used for diabetes associated cardiovascular diseases.