胰高血糖素样肽-1受体激动剂改善高果糖饮食诱导的胰岛素抵抗大鼠肝脏脂质沉积机制研究  

Mechanism of Glucagon-like Peptide-1 Receptor Agonist Improving Liver Lipid Deposition in a Rat Model of Insulin Resistance Induced by High-fructose Diet

作　　者：高哲[1] 段凯欣 吕秀芹[1] 马慧娟[1] 张志梅[1] 宋光耀[1] GAO Zhe;DUAN Kaixin;LYU Xiuqin;MA Huijuan;ZHANG Zhimei;SONG Guangyao(Department of Endocrinology,Hebei General Hospital,Shijiazhuang 050051,China;Graduate School of Hebei North University,Zhangjiakou 075000,China)

机构地区：[1]河北省人民医院内分泌科,河北省石家庄市050051 [2]河北北方学院研究生院,河北省张家口市075000

出　　处：《中国全科医学》2023年第21期2639-2646,共8页Chinese General Practice

基　　金：河北省自然科学基金资助项目(H2022307079);河北省人才工程培养资助项目(A201901015)。

摘　　要：背景 非酒精性脂肪性肝病发病率逐年升高但无特效药物,临床和基础研究显示降糖药物胰高血糖素样肽-1(GLP-1)受体激动剂能改善肝脏脂质沉积,但具体机制不明确。目的 探讨GLP-1受体激动剂改善高果糖诱导的胰岛素抵抗大鼠肝脏脂质沉积的机制。方法 2016年1—4月选取Wistar大鼠36只随机分为对照(ND)组和造模组,ND组给予普通饲料、造模组给予高果糖饲料喂养,8周后行高胰岛素-正葡萄糖钳夹实验证实造模组胰岛素抵抗形成,继续将造模组大鼠随机分为高果糖(HFD)亚组和高果糖+艾塞那肽(HFD+Ex)亚组,HFD+Ex亚组给予艾塞那肽注射液腹部皮下注射4周后,观察糖脂水平、胰岛素抵抗、肝脏脂质沉积、β-catenin表达和核转位以及脂质合成通路因子的变化。进一步用转染技术在HepG2细胞用小干扰RNA抑制β-catenin的表达观察细胞脂质沉积和脂质合成通路相关因子的变化,将HepG2细胞用25 mmol/L果糖和100 nmol/L exendin-4处理,未转染的细胞用作对照,全部细胞分为正常对照(Con)组、高果糖(HF)组、高果糖+exendin-4(HF+Ex4)组、高果糖+exendin-4+对照siRNA(HF+Ex4+Si-control)组、高果糖+exendin-4+β-catenin siRNA(HF+Ex4+Si-β-catenin)组。实验结束后收集大鼠体质量、肝指数、三酰甘油(TG)、肝脏TG、总胆固醇(TC)、游离脂肪酸(FFA)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、空腹血糖(FBG)、空腹胰岛素(FINS)、葡萄糖曲线下面积(AUC_(glu))、葡萄糖输注速率(GIR)、肝脏油红O染色,并测定大鼠肝脏及HepG2细胞固醇调节元素结合蛋白1(SREBP-1)和下游脂质合成的关键酶脂肪酸合成酶(FAS)、乙酰辅酶A羧化酶(ACC)、硬脂酰CoA脱饱和酶1(SCD-1)以及β-catenin的蛋白表达水平。结果 (1)高果糖喂养8周后造模组大鼠体质量、肝指数、肝脏TG水平均高于ND组,GIR低于ND组(P<0.05);药物干预4周后HFD亚组大鼠体质量、肝指数、TG、FFA、ALT、Background The incidence rate of nonalcoholic fatty liver disease is increasing year by year,but there is still no effective cure.Clinical and basic studies show that a type of hypoglycemic drug,namely glucagon-like peptide-1(GLP-1)receptor agonists can improve liver lipid deposition,but the specific mechanism is unknown.Objective To explore the mechanism of GLP-1 receptor agonists improving liver lipid deposition in a rat model of insulin resistance induced by highfructose diet.Methods This experiment was carried out from January to April 2016.Thirty-six Wistar rats were randomly divided into a control group(ND)receiving a normal diet and a model group receiving a high-fructose diet.After 8 weeks,a hyperinsulinemic-euglycemic clamp test was performed in the model group to verify the formation of insulin resistance.The rats in the model group were further randomized into a high-fructose(HFD)subgroup and a high fructose with exenatide(HFD+Ex)subgroup.The changes of glucose and lipid levels,insulin resistance,liver lipid deposition,the expression and nuclear translocation ofβ-catenin and lipid synthesis pathway related factors were observed in HFD+Ex subgroup at four weeks after receiving subcutaneous abdominal injection of exenatide injection.Further changes in cell lipid deposition and lipid synthesis pathway related factors were observed after inhibiting the expression ofβ-catenin with small interfering RNA(siRNA)by transfection techniques in HepG2 cells.HepG2 cells were treated with 25 mmol/L fructose,100 nmol/L exendin-4,and nontransfected HepG2 cells were used as controls.ALL of the cells were divided into normal control group(Con),high-fructose(HF)group,high fructose with exendin-4(HF+Ex4)group,high fructose with exendin-4 and control siRNA(HF+Ex4+Si-control)group,and high fructose with exendin-4 andβ-catenin siRNA(HF+Ex4+Si-β-catenin)group.After the experiment,the rats'weight and liver index,serum concentrations of triglyceride(TG),total cholesterol(TC),free fatty acid(FFA),alanine aminotransferase(ALT)

关 键 词：非酒精性脂肪性肝病 胰岛素抵抗 果糖 胰高血糖素样肽-1受体激动剂 β-catenin 肝脏脂质沉积 大鼠 

分 类 号：R589[医药卫生—内分泌]