内质网应激预处理缺血再灌注心肌时糖原合成酶激酶-3β变化对线粒体通透性转换孔的影响  

Effect of phosphoglycogen synthase kinase-3β induced by low dose of tunicamycin on mitochondrial permeability transition pore in ischemia-reperfusion myocardium

作　　者：高鲁方[1] 周涛[1] 杨列红 冯超[1] 李遂宁 向道康[1] 厉忠逵 Gao Lufang;Zhou Tao;Yang Liehong;Feng Chao;Li Suining;Xiang Daokang;Li Zhongkui(Department of Cardiac Surgery,Guizhou Provincial Peopley's Hospital,Peopley's Hospital of Guizhou University,Guiyang 550002,China)

机构地区：[1]贵州省人民医院贵州大学人民医院心外科,贵阳550002

出　　处：《中华实验外科杂志》2019年第7期1236-1239,共4页Chinese Journal of Experimental Surgery

基　　金：贵州省基础研究计划(黔科合基础[2019]1204号);贵州省卫生计生委科学技术基金项目(gzwjkj2017-1428);贵州省人民医院青年基金项目(GZSYQN[2016]01号).

摘　　要：目的观察小剂量衣霉素(TM)诱导内质网应激预处理缺血再灌注心肌时糖原合成酶激酶-3β(GSK-3β)变化对心肌线粒体通透性转换孔(mPTP)的影响.方法使用数字表法将40只成年雄性SD大鼠随机分为4组:假手术组(Sham组)、缺血再灌注组(I/R组)、I/R+衣霉素组(TM组)、I/R+衣霉素+LY294002组(TM+ LY组),每组各10只.使用结扎左冠状动脉前降支并再灌注的方法建立I/R模型,TM组在模型建立前30 min腹腔注射0.6mg/kg TM,TM+ LY组同时间点注射0.6 mg/kg TM及糖原合成酶激酶-3β(GSK-3β)磷酸化的上游信号分子蛋白激酶B(Akt)的抑制剂LY294002(10 mg/kg).记录冠状动脉穿线后、再灌注1h和2h时的血流动力学指标.再灌注2h后处死动物,观察心肌磷酸化Akt(p-Akt)、磷酸化GSK-3β(p-GSK-3β)表达水平以及mPTP开放程度.计量资料以均值±标准差(Mean±SD)表示,各组间比较采用方差分析.结果 I/R、TM、TM+ LY组与正常时比较左心室内收缩压(LVSP)、左心室内压上升/下降最大速率(±dp/dtmax)减小、左心室内舒张末压(LVEDP)增加,I/R组变化更明显.TM、TM+ LY组p-Akt及p-GSK-3β蛋白表达均高于I/R组,TM+ LY组表达均低于TM组(两组间p-Akt比较:t=2.925,P<0.01;p-GSK-3β比较:t =2.858,P<0.01),差异有统计学意义.再灌注2h时Sham、I/R、TM、TM+ LY组mPTP吸光度值变化(△A)依次为(78.9±9.2)%、(36.1±4.8)%、(61.4±8.3)%和(46.3±5.2)%,TM组△A比I/R组大,差异有统计学意义(t=3.280,P<0.01),TM+ LY组△A与TM组比较相对较小,差异有统计学意义(t=2.720,P<0.01).结论小剂量衣霉素诱导内质网应激预处理的保护作用与GSK-3β活性变化后抑制mPTP开放有关.Objective To evaluate the effect of glycogen synthase kinase-3beta (GSK-3β) activity on mitochondrial permeability transition pore (mPTP) in the protective effects of preconditioning with endoplasmic reticulum stress (ERS) induced by low dose of tunicamycin (TM) against myocardial ischemia reperfusion (I/R) injury. MethodsForty adult male sprague-dawley rats were randomly divided into four groups: Sham, TM (Rats were treatmented by TM 0.6 mg/kg at 30 min before model established), I/R, and TM+ LY [Rats were treatmented by TM 0.6 mg/kg and protein kinase B (Akt) inhibitor LY294002 10 mg/kg]. The model of I/R were established by occlusion of left anterior descending coronary artery for 0.5 h followed by reperfusion for 2 h. Hemodynamic parameters were recorded after coronary artery perforation, 1 h and 2 h after reperfusion. After 2 hours of reperfusion, the expression of phosphorylated Akt (p-Akt), p-GSK-3β and the openness of mPTP were detected in the hearts. ResultsCompared with base line, left ventricular systolic pressure (LVSP), maximum rate of increase or decrease of left ventricular pressure (±dp/dt max) decreased, and left ventricular end-diastolic pressure (LVEDP)increased in I/R group, TM group and TM+ LY group, while the change was more significantly in I/R group. The expression of p-Akt and p-GSK-3 beta protein in TM and TM+ LY group was higher than that in I/R group, and the expression of p-Akt and p-GSK-3β protein in TM+ LY group was lower than that in TM group. At 2 hours after reperfusion, degree of variation of absorbance value (△A) of the mPTP of Sham, I/R, TM and TM+ LY group were (78.9±9.2)%,(36.1±4.8)%,(61.4±8.3)% and (46.3 ±5.2)%. The △A of TM group was larger than that of I/R group (t=3.280, P<0.01). Compared with TM group, the △A of TM+ LY group was relatively small (t=2.720, P<0.01). ConclusionThe protective effect of preconditioning with ERS induced by low dose TM is related to the inhibition of mPTP opening by regulating GSK-3β activity.

关 键 词：心肌缺血再灌注损伤 内质网应激 预处理 糖原合成酶激酶-3Β 线粒体通透性转换孔 

分 类 号：R54[医药卫生—心血管疾病]