有氧运动对AKT/GSK3β介导非酒精性脂肪肝肝细胞凋亡的影响

Effect of aerobic exercise on AKT/GSK3βmediated hepatocyte apoptosis in nonalcoholic fatty liver disease

目的探讨有氧运动对蛋白激酶B/糖原合成酶激酶-3β(AKT/GSK3β)通路介导非酒精性脂肪肝肝细胞凋亡的影响。方法6周龄雄性C57BL/6J小鼠30只,随机分为对照组、模型组和模型运动组,对照组给予普通饲料,模型组与模型运动组给予高脂饲料,喂养18周。第10周,模型运动组进行有氧运动干预,连续8周。检测血清总胆固醇(total cholesterol,TC)、甘油三酯(triglycerides,TG)、丙氨酸氨基转移酶(alanine aminotransferase,ALT)、天门冬氨酸氨基转移酶(aspartate aminotransferase,AST)、低密度脂蛋白胆固醇(low-density lipoprotein-cholesterol,LDL-C)和高密度脂蛋白胆固醇(high-density lipoprotein-cholesterol,HDL-C)水平,油红O和HE染色观察肝脏病理形态,蛋白免疫印迹检测AKT、P-AKT^(Ser473)、GSK3β、P-GSK3βSer9、Caspase-3蛋白表达变化,原位末端转移酶标记技术检测肝细胞凋亡。结果(1)干预结束后,与对照组相比,模型组小鼠体重、肝指数、血清TC、TG、ALT、AST、LDL-C水平显著增高(P<0.01或P<0.05),HDL-C水平显著降低(P<0.01);与模型组相比,模型运动组小鼠体重、肝指数、血清TC、TG、ALT、AST、LDL-C水平显著降低(P<0.01或P<0.05),HDL-C水平显著升高(P<0.01)。(2)与对照组比较,模型组肝细胞脂肪性变和肝细胞脂滴数量明显增加;与模型组相比,模型运动组肝细胞脂肪性变程度明显改善,肝细胞脂滴数量明显减少。(3)与对照组相比,模型组P-AKT^(Ser473)、P-GSK3βSer9蛋白表达量显著下降(P<0.01或P<0.05),Caspase-3蛋白表达量显著升高(P<0.05),肝细胞凋亡数明显上升(P<0.05);与模型组比较,模型运动组P-AKT^(Ser473)、P-GSK3βSer9蛋白表达显著升高(P<0.01或P<0.05)、Caspase-3蛋白表达量显著下降(P<0.05),肝细胞凋亡数明显下降(P<0.01)。结论有氧运动可改善非酒精性脂肪肝,可激活AKT/GSK3β通路,增加AKT/GSK3β通路相关分子表达,从而降低Caspase-3表达,减少肝细胞凋亡。

OBJECTIVE To investigate the effect of aerobic exercise on AKT/GSK3βpathway-mediated hepatocyte apoptosis in non-alcoholic fatty liver diseases(NAFLD).METHODS A total of 306-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-GSK3βSer9and 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-GSK3βSer9in 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-GSK3βSer9protein 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/GSK3βpathway and increasing the expression of AKT/GSK3βpathway related molecules,thereby reducing caspase-3 expression and hepatocyte apoptosis.