中文摘要：

【目的】观察人参总皂甙（GS）对骨髓间充质干细胞（MSCs）分化为心肌样细胞的诱导作用。【方法】取成年SD大鼠骨髓细胞，采用密度梯度分离法与贴壁法结合获取MSCs，进行原代培养和克隆培养；采用流式细胞仪检测细胞表面抗原CD34和CD44以鉴定该法所获细胞是否为MSCs；对传至第8代的MSCs进行分组诱导，分别为GS组（终末浓度为250mg／L）、5-氮胞苷（5-aza）组（终束浓度为10μmol／L）、GS＋5-aza组（终末浓度分别为250mg／L、10μmol／L），每组再分3个亚组，分别对MSCs进行24、48、72h诱导，并设空白对照组；采用共聚焦荧光显微镜观察细胞数及阳性细胞数．计算心肌样细胞转化率；采用免疫组化法检测分化的心肌样细胞的特异性蛋白结蛋白（Desmin）和肌钙蛋白（cTnl），采用逆转录聚合酶链反应（RT-PCR）检测诱导前后心肌细胞特征性基因α-心肌肌球蛋白重链（α—MHC）和β-心肌肌球蛋白重链（β—MHC）的表达。【结果】分离培养后的细胞生长密集，形态呈纺锤状，表面抗原鉴定为CD44表达阳性，表明所获细胞为MSCs经GS、5-aza诱导后，MSCs分化成类心肌细胞，3纽的心肌样细胞转化率无显著性差异（分别为38％、35％、39％）：免疫组化和RT—PCR检测结果显示Desmin、cTnI和MHC表达均阳性，阳性细胞呈梭形和成纤维细胞样形态，表明MSCs在GS体外诱导下已向心肌样细胞转化，并具有心肌样细胞的特性。【结论】GS可体外诱导MSCs分化为心肌样细胞，为细胞移植治疗心肌梗死提供了实验依据。

英文摘要：

[ Objective] To observe the in-vitro inductive effect of ginsenosides （GS） on differentiation of rat bone marrow mesenchymal stem cells （MSC） into myocardial cells. [ Methods] Marrow stromal cells were isolated from adult SD rats, and then were cultured and cloned by density gradient method and adhesive cultivation to prepare the primary MSC. The cell surface antigens of CD34 and CD44 were detected with flow cytometer to identify MSC. After subculture, the 8th generation of continuous MSC were induced by GS （250 mg/L） and 5-aza （5-azacytidine, 10 μmol/L） and GS ＋ 5-aza （250 mg/L and 10 μmol/L respectively） for 24, 48 and 72 hours to differentiate to myogenic cells. Meanwhile, a blank control group was set to compare the effect. After the induction, myocardial cell percentage was worked out after examining MSC count and positive cells count under the phase contrast microscope. The specific proteins of Desmin and cardiac troponin I （cTnI） in myocardial cells were detected by immunohistochemistry method, and the cardiac-specific gene expression of α-MHC （myosin heavy chain） and β-MHC in myocardiocytes was examined by reverse transcription- polymerase chain reaction （RT-PCR） analysis. [Results] The cultured marrow stromal cells grew well, spindle in shape, and their CD44 expression was positive, indicating that marrow stromal cells differentiated to MSC. After induction with GS and 5-aza, MSC differentiated to myocardial cells, and the myocardial cell percentage was 38 % in GS group, 35% in 5-aza group and 39% in GS ＋ 5-aza group, the difference being insignificant. The expression of Desmin, cTnl and MHC in MSC was positive, and MSC were spindle-shaped and looked like fibroblast, indicating that MSC differentiated to myocardial cells. [ Conclusion] Ginsenosides can induce MSC to differentiate to myogenic cells in-vitro, and this will supply evidence for cell transplantation.