利拉鲁肽改善糖尿病心肌病大鼠心脏脂质异位沉积的效果和机制研究  

Beneficial Effects and Mechanisms of Liraglutide on Improving Cardiac Ectopic Lipid Deposition and Protecting Cardiac Function in Diabetic Cardiomyopathy Rats

作　　者：蔡欢[1] 何玉秀[1] 刘静芹[2] 冯然[2] 刘涛[2] 李勋 CAI Huan;HE Yuxiu;LIU Jingqin;FENG Ran;LIU Tao;LI Xun(Hebei Normal University,Department of Physical Education,Human Body Biological Information Evaluation Key Laboratory,Shijiazhuang(050024),Hebei,China)

机构地区：[1]河北师范大学体育学院人体运动生物信息测评河北省重点实验室,河北省石家庄市050024 [2]保定市第一医院内分泌科

出　　处：《中国循环杂志》2019年第10期1013-1020,共8页Chinese Circulation Journal

基　　金：河北省研究生创新资助项目(CXZZBS2017096)

摘　　要：目的:观察利拉鲁肽对糖尿病心肌病(DCM)大鼠心脏脂质异位沉积的改善效果,并探讨相关作用机制.方法:8周龄雄性Wistar大鼠60只,随机抽取8只作为对照组,其余DCM造模.DCM造模成功大鼠24只,随机分为DCM组、低剂量利拉鲁肽治疗组(LL组)及高剂量利拉鲁肽治疗组(HL组),每组各8只.LL组[0.2 mg/(kg·d)]和HL组[0.4 mg/(kg·d)]给予利拉鲁肽皮下注射,每日1次,干预8周后,行超声心动图检测心功能后麻醉处死大鼠.心脏采血检测大鼠血糖、血脂、胰岛素水平.采用苏木素伊红染色和透射电镜观察心脏形态学变化和超微结构改变;比色法测定心肌游离脂肪酸(FFA)和二酰甘油(DAG)含量;实时PCR检测腺苷单磷酸活化蛋白激酶(AMPK)、叉头框转录因子1(FOXO1)、白细胞分化抗原36(CD36)、过氧化物酶增殖物激活受体α(PPARα)和B型利钠肽(BNP)基因表达情况;蛋白免疫印迹法检测AMPK、磷酸化AMPK(p-AMPK)、FOXO1和CD36蛋白表达情况.结果:与对照组相比,DCM组大鼠空腹血糖、空腹胰岛素、胰岛素抵抗指数、甘油三酯和低密度脂蛋白胆固醇水平显著升高,胰岛β细胞功能指数显著降低;左心室射血分数、左心室短轴缩短分数和每搏输出量均显著降低,左心室舒张早期最大血流/二尖瓣心房收缩期最大血流比值(E/A)明显升高,等容舒张时间显著延长且心脏重量指数增加;心肌细胞线粒体旁和肌丝间存在大量脂滴,心肌组织中FFA和DAG水平显著升高(P均<0.05).与DCM组相比,LL组和HL组大鼠脂质异位沉积减少,心肌中AMPK mRNA和p-AMPK/AMPK蛋白表达均增加,FOXO1、CD36的mRNA和蛋白表达水平均降低,PPARα和BNP的mRNA表达水平也降低(P均<0.05).结论:利拉鲁肽通过激活AMPK-FOXO1-CD36信号通路,改善糖尿病心肌病大鼠心肌脂质异位沉积,从而改善左心室收缩和舒张功能,发挥心脏保护作用.Objectives: To observe the effects of Liraglutide on cardiac ectopic lipid deposition in diabetic cardiomyopathy (DCM) rats, and to explore the underlying mechanisms. Methods: 60 eight weeks old Wistar rats were used, 8 rats were randomly divided into control group (CON, n=8), the remaining 52 rats were used to establish diabetic cardiomyopathy models. 24 diabetes rats were randomly divided into diabetic cardiomyopathy group (DCM, n =8), Liraglutide low dose treatment group (LL, n =8) and Liraglutide high dose treatment group (HL, n =8). Rats in DL and DH group received subcutaneous injections of Liraglutide (0.2 mg/kg/day vs 0.4 mg/kg/day) for 8 weeks. Fasting blood glucose (FBG), triacylglycerol (TG), total cholesterol (TC) and insulin (FINS) levels, high density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were analyzed, HOMA-IR and HOMA-β were calculated. and echocardiography examination was performed before sacrifice. Histology and morphometric analysis of heart were performed on HE stained tissues samples and under electron microscope. The FFA and DAG concentrations in the supernatant was determined using the enzyme-based colorimetric assay to measure lipotoxicity. AMPK, FOXO1, CD36, PPARα and BNP gene expressions were detected with real-time quantitative PCR. AMPK, p-AMPK, FOXO1 and CD36 protein expressions were detected by Western blot. Results: Compared with CON group, FBG, FINS, HOMA-IR, TG and LDL-C were significantly increased, HOMA-β(P<0.05 or P<0.01), LVEF, LVFS and SV were significantly reduced, IVRT were prolonged extension, and heart mass index was increased (P <0.05 or P <0.01) in DCM rats. A large number of lipid droplets were deposited in the myocardium of diabetic rats, mainly under the myofibrillar membrane and around the mitochondria, FFA and DAG content were significantly higher in DCM rats than in CON rtas (P<0.01). After Liraglutide treatment, the AMPK mRNA expressions and p-AMPK/ AMPK relative protein expressions were significantly upregulated, mRNA

关 键 词：糖尿病心肌病 利拉鲁肽 脂质异位沉积 心脏保护 

分 类 号：R587[医药卫生—内分泌]