作者：万福生，龚文华，赵小曼，曾昭建，余乐涵，李华，李国辉
【摘要】 目的 观察牛磺酸对烧伤后心肌细胞凋亡和Fas系统的影响及初步机制。方法 选健康Wistar大鼠，随机分成对照组(Sham)、烧伤组(造成40%TBSA Ⅲ度烧伤)和烧伤加牛磺酸组(烫伤后即刻腹腔注射牛磺酸200mg/kg)。用原位末端标记(TUNEL)法检测凋亡细胞，RT-PCR检测Fas mRNA表达，免疫组化检测Fas/FasL和Caspase-8/3蛋白表达和荧光分析Caspase-3活性。结果 烧伤组大鼠伤后6h、12h和24h心肌细胞凋亡指数分别为7.31±2.31、21.52±2.57和18.67±2.48，较对照组(0.92±0.34)有显著性升高，Fas蛋白阳性表达指数分别为13.51±1.56、21.02±2.34和14.55±1.89，也显著性高于对照组(2.46±0.75)；Caspase-3活性分别为1.38±0.16、2.18±0.18和1.96±0.71，较对照组(0.35±0.06)差异有显著性。牛磺酸保护组在伤后6h、12h和24h心肌细胞凋亡指数、Fas蛋白表达和Caspase-3活性较烧伤组均有不同程度降低(P＜0.05)。烧伤组心肌细胞凋亡指数与Fas表达之间有良好的相关性(r=0.86，P＜0.05)。结论 牛磺酸对Fas系统介导烧伤后大鼠心肌细胞凋亡有较好的抑制作用。
【关键词】 牛磺酸；Fas系统；细胞凋亡；心肌；烧伤
Effects of taurine on Fas antigen involvement in apoptosis of cardiomyocytes in early postburn stage
WAN Fu-sheng，Gong Wen-hua，ZHAO Xiao-man，et al.Department of Biochemistry and Molecular Biology of Jiangxi Medical College，Nanchang 330006，China
【Abstract】 Objective To investigate the effects of taurine on the apoptosis and expression change of Fas antigen in cardiomyocytes during the early postburn stage.Methods Healthy adult Wister rats were randomly divided into the control group(without burned)，the burned group(subjected to a 40% TBSA Ⅲ degree injury)and taurine treatment group(treated by intrapleural injuction taurine 200mg/kg).Terminal deoxynucleotidy transferase-mediated dUTP fluoescein nick end labeling(TUNEL)，RT-PCR and S-P immunohistochemical staining were used respectively to determine the apoptosis and genes expression of Fas/FasL and caspase-8/3，and caspase-3 activity was detected by fluorospectrophotometry.Results Cardiomyocytes apoptosis indexs of the burned groups at 6，12 and 24 postburn hours(PBHs)are 7.31±2.1，21.52±2.57 and 18.67±2.48 respectively，positive expression indexs of Fas protein are 13.51±1.56，21.02±2.34 and 14.55±1.89 respectively，caspase-3 activity are 1.38±0.16，2.18±0.18 and 1.96±0.71 respectively，compared with the control，there are all significant increase.There are good correlation(r=0.86，P＜0.05)between cardiomyocytes apoptosis indexs and Fas gene expression of the burned groups.Compared with the burned group，cardiomyocytes apoptosis indexs，Fas gene expression and caspase-3 activity of taurine treatment group were all lowered significantly at 6，12 and 24 postburn hours(PBHs).Conclusion Fas antigen is involved in the cardiomyocyte apoptosis during the early postburn stage，and taurine exerts a good antagonist action on both Fas gene expression and apoptosis in the cardiomyocytes.
【Key words】 taurine；fas；apoptosis；cardiomyocyte；burn
牛磺酸(Taurine，Tau)是心肌中含量最丰富的游离氨基酸，具有抗氧化，调节细胞渗透压、抑制细胞钙超载等多种生物学功能［1，2］，是一种良好的内源性细胞保护剂。笔者曾发现牛磺酸对再灌注损伤心肌细胞凋亡有较好的拮抗作用［2］，其机制可能与降低Fas死亡受体通路中相关蛋白酶水平及其活性有关［3］。随着细胞凋亡现象在多种心血管疾病中被证实，Fas系统是否参与介导烧伤后心肌细胞凋亡成为目前关注的热点。研究烧伤后不同时间心肌中Fas系统的表达变化与心肌细胞凋亡的关系，对阐明严重烧伤后心功能障碍甚至“休克心”发生的机制有重要意义［4，5］，对严重烧伤后多脏器损害的防治也具有重要指导作用。牛磺酸对烧伤后心肌细胞凋亡的影响如何，尤其它是否调控Fas等凋亡相关基因的表达，目前