GLP-1对高糖诱导乳鼠心肌细胞损伤的保护作用及机制分析  

The mechanism of GLP-1 protection against high glucose induced neonatal cardiomyocytes injury

作　　者：杨啸[1] 范丽芬[1] 姚艳玲[1] 焦向英[1] 

机构地区：[1]山西医科大学生理教研室,太原市030001

出　　处：《中国心血管病研究》2014年第5期442-448,共7页Chinese Journal of Cardiovascular Research

基　　金：国家自然科学基金（项目编号：30800399）;山西省留学人员科技活动择优资助项目[项目编号：2010（97）];山西省留学归国人员科研资助项目（项目编号：2009-46）;山西省高等学校创新人才支持计划

摘　　要：目的 以高糖刺激的乳鼠心肌细胞模拟糖尿病诱导心肌细胞损伤,给予胰高血糖样多肽-1（GLP-1）预处理,观察其对高糖引起的心肌细胞凋亡的影响,以及细胞内硫氧还蛋白（Trx）系统的变化.方法 将分离培养48 h的大鼠乳鼠心肌细胞分为3组：①正常对照组：使用含葡萄糖5.5 mmol/L的DMEM培养基加入甘露醇20 mmol/L作为对照培养基进行培养;②高糖组：使用含葡萄糖25 mmol/L的DMEM培养基作为高糖培养基进行培养模拟糖尿病;③高糖＋ GLP-1组：以含葡萄糖25 mmol/L的DMEM培养基加入终浓度10 nmol/L的GLP-1继续培养模拟糖尿病GLP-1干预.心肌细胞分别在三种培养基中培养24h后测定指标.结果 ①与正常组比较,高糖组细胞乳酸脱氢酶活性、细胞凋亡率、p38激酶活性均显著升高,Trx活性明显降低（P＜0.05）;硫氧还蛋白表达无明显变化,但细胞内蛋白硝基化的标志物3-硝基酪氨酸生成量增加,Trx的内源性抑制蛋白硫氧还蛋白相互作用蛋白（TXNIP）表达明显上调,活性氧（ROS）生成和丙二醛（MDA）的含量均明显升高（P均＜0.05）.②与高糖组比较,高糖＋GLP-1组乳酸脱氢酶活性、细胞凋亡率、p38激酶活性明显降低,Trx活性明显恢复（P＜0.05）,3-硝基酪氨酸生成、TXNIP表达、活性氧生成和丙二醛的产生量均明显降低（P均＜0.05）.结论 高糖可引起培养的乳鼠心肌细胞发生损伤和凋亡,这种损伤与高糖引起的Trx活性和功能下降有关.蛋白的硝基化、TXNIP的表达上调均可抑制Trx的活性,使其抗自由基和抗凋亡功能减弱,自由基生成增加,p38激酶介导的凋亡途径加强,进而引起心肌细胞损伤和凋亡.GLP-1处理可使高糖引起的TXNIP表达明显下调,蛋白硝基化减轻,Trx活性得到改善,细胞自由基损伤和凋亡减轻,通过对Trx系统的保护而逆转高糖引起的细胞损伤和凋亡.Objective This study was designed to identify whether GLP-1 can relieve the apoptosis of neonatal rat cardiomyocyte induced by glucose toxicity,the mechanisms responsible for the effect of GLP-1 were also analyzed.Methods Cardiomyocytes cultured in 48 hours were then randomly divided into 3 groups：normal glucose group,high glucose group and high glucose＋GLP-1 group.For normal glucose group,cardiomyocytes were cultured in DMEM containing 5.5 mmol/L glucose and 20 mmol/L mannitol served as a normal control.For the two high glucose groups,cardiomyocytes were cultured in high glucose DMEM containing 25 mmol/L glucose.Cardiomyocytes in high glucose＋GLP-1 group were pretreated with GLP-1 （10 nmol/L final concentration） for and then high glucose DMEM.After additional 24 hours culture,cells and medium were collected for further assays.Results （1）Compared with control group,high glucose group showed increased activity of LDH,apoptosis rate,p38 kinase activity,quantitation of cellular 3-Nitrotyrosine content,TXNIP expression,reactive oxygen species generation,malondialdehyde （MDA） contents in cardiomyocytes and depressed activity of TRX.（2）Compared with High glucose group,high glucose and GLP-1 group showed depressed activity of LDH,apoptosis rate,p38 kinase activity,quantitation of cellular 3-Nitrotyrosine content,TXNIP expression,reactive oxygen species generation,malondialdehyde （MDA） contents in cardiomyocytes and increased activity of TRX.Conclusion High glucose induces increased cell damage and cell apoptosis,with the generation of free radical,lipid peroxidation damage and TRX system change,the decrease of TRX activity,and down regulate of TXNIP expression.Treatment with GLP-1 relieves recovered Trx activity,decreases intracellular reactive oxygen species generation,MDA content,3-nit^otyrosine production and TXNIP expression are decrease markedly.GLP-1 successfully relieves high glucose induced cell injury and apoptosis.

关 键 词：硫氧还蛋白 凋亡 胰高血糖样多肽-1 心肌细胞 

分 类 号：Q95-33[生物学—动物学] R542.2[医药卫生—心血管疾病]