摘要目的 探讨重组人硫氧还蛋白(TRX)对病毒性心肌炎小鼠心肌细胞凋亡的影响及对凋亡相关蛋白表达的调节作用.方法 Balb/c小鼠24只,体质量12～14 g,按体质量随机分为对照组、病毒组和TRX保护组,每组8只.病毒组和TRX保护组小鼠给予腹腔注射100TCID50柯萨奇B3病毒(CVB3)0.1 ml,对照组给予等量生理盐水.同时,TRX保护组给予尾静脉注射TRX(2 mg/kg),病毒组给予等量生理盐水.14 d后处死小鼠,光镜下观察心肌组织病理形态学改变,采用TUNEL法检测心肌细胞凋亡,采用免疫组化法检测凋亡相关蛋白(Bcl-2、caspase-3)的表达.结果 ①光镜结果显示,病毒组小鼠心肌细胞有局灶性坏死和炎细胞浸润;TRX保护组心肌细胞可见散在的凝固性坏死和细胞水肿;对照组心肌细胞未见明显异常.②凋亡检测结果显示,病毒组和TRX保护组凋亡指数[(90.23±3.63)％、(20.02±2.41)％]明显高于对照组(0.00±0.00,P均＜0.05),TRX保护组凋亡指数较病毒组明显降低(P＜0.05).③免疫组化结果显示,病毒组和TRX保护组Bcl-2蛋白阳性表达(+、++、+++)明显高于对照组(P均＜ 0.05),TRX保护组Bcl-2蛋白表达较病毒组明显增加(P＜0.05);病毒组和TRX保护组caspase-3蛋白阳性表达(+、++)明显高于对照组(P均＜0.05),TRX保护组caspase-3蛋白表达较病毒组明显降低(P＜0.05).结论 TRX能够抑制病毒性心肌炎小鼠心肌细胞凋亡,对心肌细胞凋亡的抑制作用与调节凋亡相关蛋白表达有关.

abstractsObjective To investigate the influence of recombinant thioredoxin (TRX)on apoptosis of myocardium cell in viral myocarditis of mice.Methods Twenty-four Balb/c mice,weighting 12 - 14 g,were randomly divided into 3 groups:the control group,the virus group and the protective group,8 mice in each group.The virus group and the protective group were injected with 0.1 ml 100TCID50 Coxackie virus B3 (CVB3)intraperitoneally,and the control group was injected equal volume of saline.Therewithal the protective group was injected with TRX(2 mg/kg) by tail vein,and the virus group was injected saline the same way.After 14 days all mice were killed and hearts were taken.Changes of myocardial histopathology was observed with optical microscope,cell apoptosis was checked by TUNEL technique,and the expression of apoptosis-related proteins (Bcl-2,caspase-3)in infiltrated cell of myocardium was determined by immunohistochemistry.Results (①)Lymphocyte infiltration and necrosis were observed in survivals of the virus group,sporadic coagulation necrosis and ballooning degeneration of cells were observed in the protective group,however no myocardial lesion was found in the control group.(②)TUNEL technique showed that the positive ratio of apoptosis in the virus group and the protective group[(90.23 ± 3.63)％,(20.02 ± 2.41)％] was significantly higher than that of the control group(0.00 ± 0.00,all P ＜ 0.05),the positive ratio of apoptosis in the protective group was significantly lower than that of the virus group (P ＜ 0.05 ).(③)Immunohistochemistry showed that the expression of protein Bcl-2(+,++,+++) in the virus group and the protective group was significantly higher than that of the control group (all P ＜ 0.05).The expression of protein Bcl-2 in the protective group was significantly higher than that of the virus group(P ＜ 0.05).The expression of caspase-3 (+,++) was significantly higher in the virus group and the protective group than the control group (all P ＜ 0.05).Compared with the virus group,the expression of caspase-3 in the protective group was significantly lower(P ＜ 0.05).Conclusion TRX could inhibit cardiomyocyte apoptosis in viral myocarditis mice and the inhibition is related to regulation of apoptosis-related protein expression.