中文摘要：

【目的】观察黄芪甲苷体外诱导骨髓间充质干细胞（MSCs）定向分化为心肌样细胞的作用。【方法】采用密度梯度离心和贴壁培养法分离大鼠MSCs，反复传代及纯化后，取第3代MSCs，采用流式细胞仪检测细胞表面抗原CD34和CD44：取第8代MSCs进行分组谤导：黄芪甲苷组（终浓度为250mg／L）、5-氮胞苷（5-aza，终浓度为10mmol／L）、黄芪甲苷加5．aza组（终浓度分别为250mg／L与10mmol／L），并设空白对照组，诱导后继续培养4周；计算心肌样细胞诱导率，采用免疫组化法鉴定诱导后MSCs中结蛋白（Desmin）和心肌特异性肌钙蛋白I（删）的表达，采用逆转录聚合酶链反应（RT-PCR）法鉴定诱导后MSCs中心肌特异性蛋白廿心肌肌球蛋白重链（α-MHC）和β-心肌肌球蛋白重链（阻MHc）信使核糖核酸（mRNA）的表达。【结果】原代培养的MSCs首先形成集落，传代细胞体积变大，诱导后细胞呈梭形，并出现肌管；MSCs表面抗原CD44表达阳性，而骨髓造血干细胞表面抗原CD34表达阴性，表明本实验方法所得细胞为均一的MSCs细胞群；各组在不同时间的心肌样细胞诱导率无明显差异；免疫组化结果显示诱导后MSCs表达心肌特异性蛋白Desmin和cTnI；RT-PCR结果显示诱导后MSCs表达成熟的心肌特异性蛋白α-MHC和β-MHc。【结论】黄芪甲苷可在体外诱导大鼠MSCs定向分化为心肌样细胞，但诱导率仍有待提高。

英文摘要：

[Objective] To observe the in-vitro effect of astragaloside （AG） on inducing bone marrow mesenchymal stem cells （MSCs） to differentiate into cardiomyogenic cells. [Methods] MSCs were isolated from adult SD rats, and then were cultured and cloned by density gradient method and adhesive cultivation. The cell surface antigens of CD34 and CD44 in the third generation of MSCs were detected with flow cytometer. The 8^th generation of continuous MSCs were induced by AG 250 mg/L and 5-azacytidine （5-aza） 10 mmol/L separately and by the above two together to differentiate into myogenic cells. Meanwhile, a blank control group was set up. After induction, MSCs were cultured for 4 weeks and cardiomyogenic cell percentage was worked out, the expression of specific proteins of Desmin and cardiac troponin I （cTnI） in cardiomyogenic ceUs was detected by immunohistochemical method, and the mRNA expression of cardiacspecific genes of α-MHC （myosin heavy chain） and β-MHC in myocardiocytes was examined by reverse transcription- polymerase chain reaction （RT-PCR） analysis. [Results] The colony of primary MSCs fomaed firstly. The cultured MSCs grew well： big in size, spindle-shaped and myotube formation. And CD44 expression of MSCs was positive while that of CD34 expression of bone marrow hematopoietic stem cells was negative, indicating the success of the MSCs culture. After induction with AG and 5-aza, the difference of myogenic cell percentage was insignificant. The expression of Desmin, cTnI,and MHC in MSCs was positive, indicating that MSCs differentiated into cardiomyogenic cells. [Conclusion] Astragaloside can induce MSCs to differentiate into cardiomyogenic cells in-vitro, but the induction rate still need to be increased.