中文摘要：

背景：Notch信号系统在调控骨髓间充质干细胞的定向分化中起关键作用,但尚无涉及干细胞分化为心肌细胞及其分化机制的报道。目的：分析Notch信号系统在骨髓间充质干细胞分化为心肌细胞过程中的调控作用。方法：将分离培养的骨髓间充质干细胞与心肌细胞共培养,Jagged1组加入Notch激活剂Jagged1,DAPT组加入Notch激活剂Jagged1和抑制剂DAPT,对照组加入PBS缓冲液。用反转录-聚合酶链反应、免疫组化等方法检测干细胞分化为心肌细胞的情况及Notch信号系统的表达。结果与结论：骨髓间充质干细胞在体外可分化为心肌细胞,与DAPT组及对照组相比,Jagged1组的干细胞分化为心肌细胞的比率提高,心肌标志物表达增多,并且Notch1和Jagged1表达增强。证实Notch信号系统对骨髓间充质干细胞分化为心肌细胞起正向调控作用。

英文摘要：

BACKGROUND：Notch signaling system has an important role of regulating the differentiation of bone marrow mesenchymal stem cells（BMSCs）.However,there are no reports about Notch signaling system effect on differentiation and mechanism of BMSCs into cardiomyocytes.OBJECTIVE：To investigate the regulation of differentiation of BMSCs into cardiomyocytes by Notch signaling system.METHODS：BMSCs were cocultured with neonatal rat ventricular myocytes in vitro.Jagged1,an activator of the Notch signaling system,was added into the culture medium of the experiment group.The control group was added with Jagged1 and DAPT,an inhibitor of the Notch signaling system.The cells were cultured in the medium added with phosphate-buffered saline used as blank control group.Then the cultured cells were collected.The expression of Notch signal and TnT was detected by RT-PCR and immunohistochemistry.RESULTS AND CONCLUSION：BMSCs can differentiate into cardiomyocytes in vitro.Compared with the two control groups,the differentiate percentage was higher in the experimental group.RT-PCR showed that the expression level of the receptor Notch1 and the ligand Jagged1 was significantly higher.Immunohistochemistry showed a significantly increased expression of TnT.When the Notch signaling system is activated,the differentiation of BMSCs into cardiomyocytes enhances,while the effect can be inhibited by DAPT.