中文摘要：

目的观察骨髓间充质干细胞（MSCs）向心肌诱导分化过程中，低压脉动电刺激对心肌转录因子GATA－4和Nkx2．5基因表达的影响，探讨电刺激对骨髓间充质干细胞向心肌分化过程的影响及其分子生物学机理。方法体外培养大鼠骨髓间充质干细胞，取第3代MSCs，对照组以10μmol／L 5-氮胞苷（5-aza）诱导，电场组诱导后施加1．5V／cm电场刺激，分别于第1、2、3、4周收集细胞，免疫细胞化学法和western blot技术检测troponin I（Tn I）表达，RT—PCR法分析GATA－4和Nkx2．5基因的表达。结果诱导后细胞停止生长，并倾向集落化，诱导第2周开始出现Tn I阳性细胞，TnI蛋白在诱导后第2周开始表达，第3、4周明显增强。GATA－4和Nkx2．5基因第1周开始表达，第2周增强，第3周达到高峰，持续到第4周。电场刺激组细胞排列更加紧密，诱导后各时间点GATA－4和Nkx2．5基因表达比对照纽明显增强。结论脉动电场刺激促进MSCs向心肌细胞的分化过程，GATA－4和Nkx2．5基因可能调节该促进过程。

英文摘要：

[Objective] To investigate the influence of low pressure pulse electric stimulation on the the expression of the transcriptive factors, GATA-4 and Nkx2.5 mRNA, in the course of differentiation of mesenchymal stem cells （MSCs） into cardiomyocytes, analysing it＇s molecular biological mechanism. [Methods] Rattus mesenchymal stem cells were cultured in vitro and 3^nd generation was induced in 10 μmol/L 5-azacytidine in control group, 1.5 V/ cm pulse electric stimulation was used in electric group, troponin I was checked with immunohistochemistry and western blot, GATA-4 and Nkx2.5 Gene were analyzed by RT-PCR in 1, 2, 3 and 4 weeks respectively. [Results] Growth of MSCs stopped after being induced, trending to colony, troponin I positive expressed since 2^nd week, increased at 3^rd and 4^th week, GATA--4 and Nkx2.5 began to express in 1^st week, increased gradually, peaked in 3^rd week. [Conclusion] Pulse electric stimulation improved the course of differentiation of MSCs into cardiac myocytes, which may be regulated by GATA-4 and Nkx2.5.