KLF14过表达促进肝细胞糖摄取的机制研究  

Mechanism of KLF14 overexpression-stimulated glucose uptake in hepatocytes

作　　者：任艳[1] 李伶[1] 杨刚毅[2] 代继桓 贾彦军[1] 罗小河[1] 冉文侠[1] 曾梦[2] 

机构地区：[1]重庆医科大学检验医学院,临床生化教研室和教育部临床检验诊断学重点实验室,400016 [2]重庆医科大学附属第二医院内分泌科

出　　处：《中华内分泌代谢杂志》2015年第5期457-461,共5页Chinese Journal of Endocrinology and Metabolism

基　　金：国家自然科学基金项目（81270913,81070640,81100567,81300702和81300670）,教育部博士点基金（20105503110002,20125503110003）,重庆市自然科学基金重点项目资助（estc2012jjBl0022）

摘　　要：目的观察Kruppel样因子14（KLFl4）基因过表达对肝细胞胰岛素信号通路以及AMP活化的蛋白激酶（AMPK）关键信号分子的影响，探讨KLFl4影响糖代谢的分子机制。方法建立KLFl4过表达的Hepal-6肝癌细胞模型，分为空载组、胰岛素组、KLFl4转染组和胰岛素＋KLFl4处理组，采用[3H]-2-脱氧-D-葡萄糖摄取法检测肝癌细胞对葡萄糖的摄取率。以Western印迹检测KLFl4过表达对胰岛素信号通路中各信号分子的磷酸化水平及磷酸烯醇式丙酮酸激酶（PEPCK）蛋白表达的影响。结果胰岛素处理Hepal-6细胞后，KLFl4转染组与未转染组相比，葡萄糖摄取率明显升高（P〈0．01）；胰岛素受体（InsR）、胰岛素受体底物（IRS）1、蛋白激酶B（Akt）、AMPK、CREB转录共激活因子2（TORC2）的磷酸化水平均明显增加（P〈0．01）；而且，糖原合成酶激酶3B的磷酸化水平亦明显增加，而PEPCK的蛋白表达明显降低，差异均有统计学意义（P〈0．01）。结论KLFl4过表达可能通过活化胰岛素InsR／IRS／Akt经典通路，从而改善肝细胞的胰岛素抵抗，且可能通过AMPK／TORC2／PEPcK信号通路抑制肝糖异生，并促进糖摄取和肝糖原的合成，从而改善糖代谢。Objective To observe the effect of Kruppel-like factor 14 （KLF14） gene overexpression on the key molecules in insulin and AMP-activated protein kinase （AMPK） signal pathways, and to investigate the molecular mechanism underlying KLF14-regulated glucose metabolism. Methods KLF14 gene was overexpressed in Hepal-6 hepatocytes, which was divided into four groups ： empty vector group （ EV）, insulin treatment group （ INS）, KLF14 transfection group, and insulin plus KLF14 group. Glucose uptake was determined by 2-deoxy-D-[ 3 H ]-glucose uptake assay in hepatic ceils. Protein phosphorylations of key signaling molecules and phosphoenolpyruvate carboxykinase （PEPCK） protein expression were detected by Western blot. Results Compared with EV group, the glucose uptake rate was increased significantly in groups with KLF14 transfection after Hepal-6 hepatocytes were treated with insulin （P〈0.01）. Furthermore, the phosphorylation of insulin receptor, insulin receptor substrate 1, protein kinase B （ Akt）, AMPK, and CREB-regulated transcription coactivator 2 （ TORC2 ） were significantly enhanced after KLF14 transfection and insulin treatment （P〈0.01）. In addition, the phosphorylation of glycogen synthase kinase 36 protein was also elevated while PEPCK protein expression was decreased （ P〈0.01 ）. Conclusions KLF14 gene overexpression may play a role in improving hepatic insulin resistance by activating the classical pathway of insulin. Additionally, it may ameliorate glucose metabolism via inhibiting gluconeogenesis, promoting glucose uptake, and glycogen synthesis.

关 键 词：Kruppel样因子14 胰岛素 AMP活化的蛋白激酶 信号通路 

分 类 号：R587.1[医药卫生—内分泌]