磷酸腺苷激活的蛋白激酶在慢性应激诱发小鼠非酒精性脂肪肝中的作用

Role of adenosine monophosphate-activated protein kinase in mice with non-alcoholic fatty liver disease induced by chronic stress

目的探讨磷酸腺苷激活的蛋白激酶(AMPK)及其激动剂5-氨基咪唑-4-甲酰胺核苷酸(AICAR)在慢性应激诱发小鼠非酒精性脂肪肝(NAFLD)中的作用。方法建立小鼠慢性应激模型,设对照组、应激组、应激加AICAR给药组和AICAR给药组,每组6只。采用ELISA法检测小鼠血浆促炎性细胞因子(肿瘤坏死因子α,γ干扰素)浓度,采用自动生化分析仪检测小鼠血浆丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、总胆固醇、三酰甘油、游离脂肪酸的水平,采用苏木精-伊红染色和油红O染色检测肝细胞脂肪变性,采用蛋白质印迹法检测肝组织AMPK蛋白表达;然后用AICAR处理慢性应激小鼠并检测上述指标的变化。结果慢性应激导致小鼠肝细胞脂肪变性,肝功能损害(ALT、AST水平升高,P<0.01),血浆促炎性细胞因子浓度升高(P<0.05),血浆游离脂肪酸水平升高(P<0.01)以及肝组织AMPK蛋白表达降低(P<0.01)。AICAR改善了肝细胞脂肪变性,并缓解了上述指标的变化。结论慢性应激可能通过AMPK信号通路诱发NAFLD,AMPK激动剂AICAR可缓解慢性应激导致的NAFLD。

Objective To investigate the role of adenosine monophosphate-activated protein kinase(AMPK)and its agonist 5-aminoimidazole-4-carboxamide-ribonucleoside(AICAR)in mice with chronic stress-induced non-alcoholic fatty liver disease(NAFLD).Methods BABL/c mice were randomly divided into control group,stress group,stress plus AICAR group(ST+A group)and AICAR group.The mouse models of chronic stress was established in the stress and ST+A groups,and the mice were injected with AICAR 500 mg/kg in the ST+A and AICAR groups.Before and after treating with AICAR,the levels of pro-inflammatory cytokines(tumor necrosis factorα[TNF-α]and interferonγ[IFN-γ])in plasma of mice were detected by ELISA,the levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),total cholesterol,triglyceride and free fatty acid in plasma were determined by automatic biochemical analyzer,the hepatic steatosis was detected by hematoxylin-eosin(H-E)staining and Oil Red O staining,and the expression of AMPK protein in liver tissues was detected by Western blotting.Results Chronic stress caused liver function damage(the levels of ALT and AST were significantly increased,P<0.01)and liver steatosis in mice,the levels of pro-inflammatory cytokines(P<0.05)and free fatty acid(P<0.01)were significantly increased and the liver AMPK protein expression was significantly decreased(P < 0.01). AICAR improved the liver cell steatosis,and alleviated the changes of above indicators.Conclusion Chronic stress may induce NAFLD through AMPK signaling pathway,and AMPK agonist AICAR can alleviate NAFLD caused by chronic stress.