心肌直接接触诱导骨髓间充质干细胞成心肌样分化

Direct cell-to-cell contact with cardiomyocytes is necessary for transdifferentiation of mesenchymal stem cells into cardiomyocytes

目的应用新生大鼠心肌细胞(CM)与骨髓间充质干细胞(MSCs)体外共培养的方法模拟心肌内环境,研究模拟环境下MSCs分化为CM的相关因素及其适宜条件。方法利用CM与MSCS不同比例直接接触和非直接接触共培养的方法模拟心肌微环境,分析MSCS形态和结构蛋白表达等方面的变化。结果直接接触共培养的MSCS与CM同步搏动,表达心肌特异性肌钙蛋白T,且MSCs与CM等比例培养时分化率最高;而在缺乏直接接触条件下,单纯的CM条件培养液无法单独诱导MSCS的横向分化。结论与CM间的直接接触为诱导MSCS分化为CM的必需条件,共培养的细胞密度对于诱导分化率有影响,条件培养液则非关键因素。

Objective To explore the related mechanisms and optimal conditions of mesenchymal stem cells (MSCs) differentiating into cardiomyocytes(CM) in a simulated cardiac micro-environment in vitro. Methods We cultured MSC_S with CM in various ratios and in the presence of media conditioned by separate cultures of cardiomyocytes. Morphological changes and expression of cardiac specific proteins in MSC_S were investigated and analysed. Results Only in the cocultured group, MSC_S could be stained positive for cardiac Troponin T. And Troponin T-positive rate was highest when MSC_S were cocultured with CM at 1∶1 ratio. Conclusions Only direct cell-to-cell contact in unconditioned media is obligatory for transdifferentiation of MSC_S into cardiomyocytes. The cell density can affect the differentiation rate.