牛磺酸对心肌细胞缺氧/复氧凋亡的保护及机制  

Protective roles and mechanisms of taurine on myocardial hypoxia/re-oxygenation-induced apoptosis

作　　者：韩畅畅 杨晓红[1] 万慧芳[2] 余乐涵[2] 余波[1] 万福生[1] 

机构地区：[1]南昌大学基础医学院生物化学与分子生物学教研室,江西南昌330031 [2]南昌大学医学实验教学中心,江西南昌330031

出　　处：《南昌大学学报（理科版）》2017年第4期349-354,367,共7页Journal of Nanchang University(Natural Science)

基　　金：国家自然科学基金资助项目(81360032)

摘　　要：为探讨牛磺酸对心肌缺血/再灌注(I/R)损伤的细胞保护作用及分子机制。采用大鼠乳鼠心肌细胞制备缺氧/复氧(H/R)损伤模型,用基因转染及siRNA靶向基因沉默技术,MTT法检测细胞存活率,流式细胞术检测细胞凋亡率,RT-PCR检测mRNA表达、Western blot检测蛋白表达。结果显示:与H/R组比较,3个牛磺酸保护组的心肌细胞凋亡率均有显著下降(P<0.05);随着牛磺酸浓度的增加,H/R心肌细胞中Bcl-2蛋白表达逐渐升高(P<0.05),而PUMA、CHOP、Bax、Grp78和Caspase-3蛋白表达则逐渐下降(P<0.01);牛磺酸对心肌细胞转染PUMA过表达有较强的下调作用;靶向沉默PUMA后细胞凋亡率呈显著下降,靶向沉默CHOP后PUMA表达下调(P<0.05)。结果表明牛磺酸对心肌细胞H/R导致的凋亡有较好的抑制作用,其机制可能与牛磺酸能下调CHOP表达,进而抑制促凋亡蛋白PUMA表达有关。To investigate the protective role of taurine（TAU）on myocardial ischemia/reperfusion（I/R）-induced cell apoptosis and the underlying mechanisms,cardiomyocytes of neonatal rats were used to prepare the hypoxia/re-oxygenation（H/R）injury model.The techniques of gene transfection and small interfering RNA target gene silencing were performed,which utilize a methyl thiazolyl tetrazolium assay to detect cell survival,the flow cytometry to detect cell apoptosis and western blot analysis to detect protein expression.The results showed that the H/R-induced apoptosis was significantly decreased by treatment with Tau compared with that in the untreated H/R group（P〈0.05）.As the Tau concentration increased,the expression of B cell lymphoma 2（Bcl-2）protein in H/R cardiomyocytes was gradually increased（P〈0.05）,while the protein expression of p53 up-regulated modulator of apoptosis（PUMA）,C/EBP homologous protein（CHOP）,Bcl-2-associated protein（Bax）,glucose regulated protein 78 kD（Grp78）and caspase-3 decreased gradually（P〈0.05）.Tau can down-regulate the expression of PUMA in PUMA-transfected cardiomyocytes.Following the targeted silencing of PUMA,the apoptosis rate significantly decreased.The targeted silencing of CHOP significantly reduced the expression of PUMA（P〈0.05）.These results indicated that Tau significantly inhibited myocardial H/R-induced apoptosis and the potential mechanisms may be associated with the down-regulation of CHOP apoptosis pathway in myocardial ischemia/reperfusion.

关 键 词：牛磺酸 缺血/再灌注损伤 细胞凋亡 C/EBP同源蛋白 心肌 

分 类 号：Q257[生物学—细胞生物学]