葡萄糖和含腺苷分子通过碳水化合物反应元件结合蛋白(ChREBP)诱导猪脂肪细胞硫氧还蛋白互作蛋白(Txnip)的表达  

Glucose and Adenosine- containing Molecule Stimulate Expression of Thioredoxin Interacting Protein(Txnip) mRNA through Carbohydrate Response Element Binding Protein(ChREBP) in Primary Cultured Porcine Adipocytes

作　　者：张国华[1] 卢建雄[1] 杨具田[1] 臧荣鑫[1] 申晓蓉[1] 赵永清[1] 霍生东[1] 陈妍[1] 

机构地区：[1]西北民族大学生命科学与工程学院/甘肃省动物细胞工程技术研究中心,兰州730030

出　　处：《农业生物技术学报》2014年第3期280-288,共9页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金项目(No.30871811;No.31060311);西北民族大学中央高校基本科研业务费专项基金(No.31920130049)

摘　　要：硫氧还蛋白互作蛋白（Txnip）是一种氧化还原调节蛋白，通过与硫氧还蛋白结合抑制其活性，调节细胞的氧化还原状态，在葡萄糖和脂质稳态中起重要作用。本研究利用从3～7日龄仔猪（Susscrofa）皮下脂肪组织分离培养的脂肪细胞，应用RNAi沉默碳水化合物反应元件结合蛋白基因（ChREBP）表达，以含0或0．1mmol／LNAD＋的葡萄糖浓度分别为0、5和15mmol／L的培养液培养，采用实时荧光定量PCR检测Txnip及ChREBPmRNA表达，以探讨葡萄糖和含腺苷分子对猪脂肪细胞Txnip表达的影响及其转录调控途径。结果表明，葡萄糖以浓度依赖方式促进猪脂肪细胞Txnip和ChREBPmRNA表达，无糖条件下NAD＋对Txnip mRNA表达没有明显影响，但葡萄糖存在时显著促进其表达。siRNA沉默脂肪细胞ChREBP表达后，葡萄糖对Txnip mRNA表达的促进作用比相同条件下培养的对照细胞有较大幅度降低；以NAD＋处理后，Txnip表达在葡萄糖浓度为5和15mmol／L时分别较对照细胞降低了91％和93％。由此说明，NAD＋诱导猪脂肪细胞Txnip转录表达依赖于葡萄糖的参与，ChREBP介导葡萄糖和NAD＋对Txnip mRNA表达的诱导作用。研究结果为进一步探讨ChREBP在葡萄糖和脂质稳态中的作用提供了基础。Thioredoxin interacting protein （Txnip） is a multifunctional protein involved in many cellular and physiological processes, and can regulate cellular redox state by inhibiting the activity of thioredoxin. To explore effects of glucose and adenosine-containing molecule on expression of Txnip mRNA and regulation pathway for transcription in porcine adipocytes, the preadipocytes isolated from subcutaneous adipose tissue obtained from 3-7 days old piglets（Sus scrofa） were cultured and induced to differentiate into mature adipocytes, in which carbohydrate response element binding protein gene （ChREBP） was silenced by transfection of ChREBP-RNAi expression plasmid. Non-transfected and transfected adipocytes were cultured in medium with 0, 5 or 15 mmol/L glucose with or without NAD ~ for 24 h. Expression level of Txnip and ChREBP mRNA was determined by fluorescence Real-time PCR. The results showed that ChREBP mRNA expressions were up-regulated 4.57 and 6.69 times （P〈0.01） in porcine adipocytes cultured in medium with 5 mmol/L or 15 mmol/L glucose, respectively, but there was no difference （P〉0.05） in the cells cultured in same glucose concentrations of medium with or without NAD~, which indicated NAD~ alone or accompanied by glucose have no effect on the ChREBP mRNA expression. Expression of Txnip mRNA was increased by glucose stimulation （P〈0.01）. Txnip mRNA expression was not elevated by NAD＋ under glucose-free condition （P〉0.05）, but increased significantly in the presence of glucose （P〈0.01）. In ChREBP-silencing adipocytes, levels of Txnip mRNA expression had no difference （P〉0.05） and slightly increased by glucose （P 〈 0.05; - 1.34 times） compared with non- transfected adiocytes cultured in glucose- free medium. However, this stimulation of glucose on Txnip mRNA expression was reduced 82% and 91% in ChREBP-silencing adipocytes cultured in medium with 5 mmol/L and 15 mmol/L glucose than that in non-transfected cells cultured under the same condition, respectiv

关 键 词：葡萄糖 NAD+ 硫氧还蛋白互作蛋(Txnip) 碳水化合物反应元件结合蛋白(ChREBP) 猪脂肪细胞 转录 

分 类 号：S828.1[农业科学—畜牧学]