Objective: To investigate the effect of aerobic exercise on AKT/GSK3β pathway-mediated hepatocyte apoptosis in non-alcoholic fatty liver diseases(NAFLD).
Methods: A total of 30 6-week-old male C57BL/6J mice, and mice were fed adaptively for one week. The control group was fed with ordinary diet, and the model group and model exercise group were fed with high-fat diet until 18 weeks. At the 10th week of the experiment, the model exercise group received aerobic exercise intervention for 8 consecutive weeks until the end of the experiment at the 18th week. Automatic biochemical analyzer to detect serum total cholesterol(TC), triglycerides(TG), alanine aminotransferase(ALT), aspartate aminotransferase(AST), low-density lipoprotein(LDL-C) and high-density lipoprotein(HDL-C) levels. Liver pathological morphology was observed by staining with oil red O and HE. The expression changes of AKT, P-AKT~( Ser473), GSK3β, P-GSK3β~(Ser9) and Caspase-3 proteins were detected by western blot, and the apoptosis of hepatocytes was detected by in situ terminal transferase labeling(TUNEL).
Results: (1) After intervention, compared with control group, body weight, liver index, serum TC, TG, ALT, AST and LDL-C levels in model group were significantly increased(P<0.01 or P<0.05), while HDL-C level was significantly decreased(P<0.01). Compared with model group, body weight, liver index, serum TC, TG, ALT, AST and LDL-C levels in model exercise group were significantly decreased(P<0.01 or P<0.05), while HDL-C level was significantly increased(P<0.01). (2) Compared with the control group, hepatocyte steatosis and the number of lipid droplets in model group were significantly increased. Compared with the model group, the degree of hepatic adipose degeneration was significantly improved and the number of hepatic lipid droplets was significantly decreased in the model exercise group. (3) Compared with control group, the protein expression levels of P-AKT~(Ser473) and P-GSK3β~(Ser9) in model group were significantly decreased(P<0.01 or P<0.05), the protein expression levels of Caspase-3 were significantly increased(P<0.05), and the number of hepatocyte apoptosis was significantly increased(P<0.05). Compared with model group, the expression of P-AKT~(Ser473) and P-GSK3β~(Ser9) protein in model exercise group was significantly increased(P<0.01 or P<0.05), the expression of Caspase-3 protein was significantly decreased(P<0.05), and the number of hepatocyte apoptosis was significantly decreased(P<0.01).
Conclusion: Aerobic exercise can effectively improve NAFLD, by activating AKT/GSK3β pathway and increasing the expression of AKT/GSK3β pathway related molecules, thereby reducing caspase-3 expression and hepatocyte apoptosis.
Keywords: AKT; GSK3β; apoptosis; exercise; nonalcoholic fatty liver.