利拉鲁肽对小鼠骨骼肌细胞葡萄糖转运子4转位的作用

Effect of liraglutide on glucose transporter 4 translocation of mouse skeletal muscle cells

目的 探讨胰高血糖素样肽1 （GLP-1）类似物利拉鲁肽对小鼠骨骼肌细胞葡萄糖转运子4（GLUT4）转位的作用及可能机制.方法 在过表达带有HA表位GLUT4的小鼠骨骼肌细胞株C2C12（C2C12-GLUT4H）,分为正常对照组、胰岛素组（100 nmol/L）、利拉鲁肽1组（100 nmol/L）、利拉鲁肽2组（1 000 nmol/L）、5-氨基咪唑-4-甲酰1-β-D呋喃糖苷（AICAR）（腺苷酸活化蛋白激酶激动剂）组（2 mmol/L）.通过ELISA法测定细胞膜上C2C12-GLUT4HA,检测各组对C2C12-GLUT4HA细胞GLUT4转位的作用.应用Western blotting检测介导GLUT4转位的信号分子蛋白激酶B（AKT）、腺苷酸活化蛋白激酶（AMPK）磷酸化水平以及GLUT4蛋白表达水平.采用Student＇s t检验或单因素方差分析进行统计分析.结果 利拉鲁肽组的GLUT4转位较对照组相比明显上升[分别是对照组的（1.53±0.28）倍、（1.41±0.41）倍,F=13.4798,P＜0.05];利拉鲁肽刺激组与对照组相比能够使pAMPK水平升高[分别是对照组的（1.79±0.31）倍、（1.54±0.18）倍,F=20.0999,P＜0.05],而对pAKT无明显影响（P＞0.05）.结论 利拉鲁肽可通过激活AMPK从而促进小鼠骨骼肌细胞GLUT4转位的增加.

Objective To investigate the effects and mechanism of glucagon-likepeptide1（GLP-1） analogue liraglutide on glucose transporter 4 （GLUT4） translocation of mouse skeletal muscle cells.Methods In overexpressing C2C12-GLUT4HA cells,observing the effects and molecular mechanism of liraglutide on GLUT4 translocation.C2C12-GLUT4HA cells were divided into the control group,insulin group（100 nmol/L）,liraglutide Ⅰ group（100 nmo]/L）,liraglutide Ⅱ group（1 000 nmol/L）,5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside （AICAR） （adenosine 5＇-monophosphate （AMP）-activated protein kinase agonist） group （2 mmol/L）.The amount of GLUT4HA on the cell surface was measured by enzyme-linked immunosorbent assay（ELISA）.The phosphorylation of adenosine 5＇-monophosphate （AMP）-activated protein kinase（AMPK）,protein kinases B （AKT）,and GLUT4 expression were tested by western blotting.Statistical analyses were performed using Student＇s t test or analysis of variance （ANOVA）.Results The amount of GLUT4HA on the cell surface in liraglutide groups was more than the amount of GLUT4HA on the cell surface in control group （1.53±0.28 vs 1.41±0.41,F=13.4798,P〈0.05）.The expression of GLUT4 was not changed in liraglutide groups and the control group.The levels of phosphorylation of AMPK were more in liraglutide groups than that in the control group（1.79±0.31 vs 1.54±0.18,respectively,F=20.0999,P〈0.05）.But the phosphorylation of AKT was not changed（P〉0.05）.Conclusion This study suggests that Liraglutide may induce GLUT4 translocation of mouse skeletal cells by activation of AMPK.