外源性细胞色素C对脓毒症小鼠心肌TGF-β1和Smad1/5/8影响的实验研究

Effects of Exogenous Cytochrome C upon TGF-β1 and Smad 1/5/8 of Mice Myocardium in Sepsis

目的探讨外源性细胞色素c(Cytc)对脓毒症小鼠心肌TGF-β1和Smad1/5/8的作用及影响。方法雄性昆明小鼠78只,随机分为假手术组(Sham)、脓毒症组(CLP)、细胞色素C处理组(T)。CLP组和T组用盲肠结扎穿孔法造模,Sham组仅开腹翻动盲肠。24 h造模成功后,T组经尾静脉注射外源性Cytc(20mg/kg)、Sham组和CLP组分别经尾静脉注射150(1生理盐水。30 min后以0、6 h、12 h点取材,每个时间点5只小鼠,测左心室收缩压(LV S1P)、左心室舒张末期压(LVEDP)、左室内压力变化最大上升和下降速率(LV±dp/dt-max);取心肌组织分别做组织学检查、RT-PCR和Western-Blot检测TGF-β1和Smad1/5/8蛋白的表达;24h点留取电镜标本,余下的小鼠观察生存率。结果与CLP组比较,T组一般情况好转,生存率提高,病理学改善;LVSP、LVEDP和LV±dp/dt-max提高(P<0.05);各组TGF-β1和Smad1/5/8蛋白均有表达,CLP组表达明显增加,经外源性Cytc干预后蛋白表达减少,CLP组与其它组比较差别有统计学意义(P<0.05)。结论外源性Cytc逆转脓毒症小鼠心肌线粒体功能抑制和心肌抑制,改善心功能。

Objective To explore the effect of exogenous cytochrome c upon the TGF-β1 and Smadl/5/8 of mice myocardium in the sepsis, reverse sepsis associated cardiomyocyte mitochondria function inhibition and myocardium depression, enhance cardiac function. Methods 78 male kunming rats were randomly divided into sham group（ Sham）, sepsis group（CLP） and exogenous cytochrome C treatment group（T）. Cecal ligationand puncture was used to reproduce rat sepsis model on the CLP group and group T, Sham group was opened abdomen and flipped appendix. 24 hours after operation, group T and Sham group and CLP group were respectively injected exogenous Cytc （20mg/kg） and 150μl saline via tail vein. 30nfin after injection, all rats were evaluated at 0,6,12 hours. Each time point there were five rats, myocardium was done histopathological examination, RT-PCR and Western-Blot experiments, detected the content of TGF-β1 and Smadl/5/8 protein; At 24h time point,heart tissues each group were detected by transmission electron microscope. Rest rats were observed the survival rate. Resuits Compared with the CLP group ,The general situation of group T improved and the survival rates generally increased ,pathological changes improved; LVSP,LVEDP and LV ＋ dp/dt-max increased （P 〈 0.05 ） ;RT-PCR and Western-Blot Detected that TGF-131 and Smadl/5/8 protein of the myocardial tissue were expressed. Protein expression of CLP group significantly increased. Group T intervened by exogenous Cytc protein expression decreased. Compared with the other groups, the difference was statistically significant （ P 〈 0.05 ）. Conclusion Exogenous Cytc could reverse sepsis associated cardiomyocyte mitochondria function inhibition and myocardial depression and improve cardiac function.