叶酸对柯萨奇病毒B3诱导乳鼠心肌凋亡保护作用

Prtoective effact of folic acid on myocardial apoptosis of offspring rats with maternal coxsackievirus B3 infection

目的探讨叶酸对柯萨奇病毒B3诱导的乳鼠心肌细胞凋亡及凋亡相关基因与蛋白表达的影响。方法取成熟健康雌性Wistar大鼠随机分为4组,分别为对照、叶酸、柯萨奇病毒B3及柯萨奇病毒B3+叶酸组;孕前灌胃给予叶酸2周,孕第5 d腹腔注射给予柯萨奇病毒B3,连续5 d;取自然分娩乳鼠心肌细胞,切片观察乳鼠心肌损伤;原位末端标记法(tunel)检测乳鼠心肌细胞凋亡;蛋白免疫印迹(western blot)及逆转录聚合酶链反应(RT-PCR)测定乳鼠心肌细胞凋亡相关Bax、Bcl-2、Caspase-3蛋白及基因表达。结果柯萨奇病毒组乳鼠心肌细胞损伤明显,凋亡细胞增加,加用叶酸后状态改善;病毒组乳鼠心肌细胞Bax、Caspase-3蛋白表达(0.608±0.060,0.951±0.038)及基因表达(0.951±0.098,0.960±0.074)高于病毒+叶酸组,病毒组Bcl-2蛋白表达(0.350±0.037)及基因表达(0.423±0.051)低于病毒+叶酸组。结论怀孕母鼠早期感染柯萨奇病毒可致乳鼠心肌细胞凋亡增加,补充叶酸对乳鼠心肌细胞凋亡具有明显保护作用。

Objective To investigate the effects of oral folic acid on myocardial apoptosis of offspring in an experi- mental model of coxsackievirus B3 （ CVB3 ） infection of pregnant rats. Methods Wistar rats were randomly divided into four groups. Female rats in each group were copulated with normal male rats. After natural birth, the hearts of neonates were taken and stored in liquid nitrogen. Myocardial pathological changes were observed for the neonatal rats. Myocardial apoptosis was quantitated with terminal doxynucleotidyl transfernase mediated nick end labeling assay. RT-PCR and western blot were adopted to detect apoptosis associated proteins. Results For the pregnant rats injected with CVB3, the myocardial cell injury was significant in their offspring rats under optical microscopy. The increases in Bax, caspase-3 mRNA （ 0. 951 ± 0. 098,0. 960 ±0. 074） and protein（0. 608 ±0. 060,0. 951 ±0. 038） level were detected in CVB3 group compared with those of folic acid ＋ CVB3 group （ 0. 496± 0. 076,0. 685 ± 0. 049 ; 0. 854 ±0. 088,0. 814 ± 0. 097 ）. The expression levels of Bcl-2 mRNA（0. 592 ±0. 063）and protein（0. 435 ±0. 041 ） were increased in folic acid ＋ CVB3 group compared with those of CVB3 group （ 0. 350± 0. 037,0. 423 ±0. 051 ）. Conclusion Folic acid supplementation can effectively inhibit myocardial cell apoptosis of the offspring of the rats injected with CVB3.