中文摘要：

分离大鼠骨髓间充质干细胞，体外培养呈现成纤维细胞表型，用12μmol／L5．氮胞苷（5-aza）诱导培养，一周后细胞变为细长形成杆状．两周后培养细胞与临近的细胞融合，三周后形成类肌管状结构．通过RT-PCR检测，5．氮胞苷诱导前，间充质干细胞表达α-actin，desmin和MEF-2D，5-aza诱导后表达β-MHC和GATA4-WesternBlot分析结果表明α-actin在诱导前后都表达，而myosin则在诱导后才表达．免疫荧光标记α-actin和β-MHC，证实了上述结果，即在5-氮胞苷诱导前后细胞表达α-actin，诱导后myosin才在细胞质中表达，Myosin和β-MHC是心肌细胞特异表达的蛋白．上述结果表明骨髓间充质干细胞具有向新生心室肌分化的潜能，这些诱导分化的细胞为心肌梗塞移植治疗提供一种潜在的供体细胞．

英文摘要：

Bone marrow （BM） stromal cells have many characteristics of stem cells and have ability to differentiate into mesenchymal tissues. Mescenchymal stem cells （MSC） were isolated from BM mononuclear cells （BMNC）, which showed a fibroblast-like morphology. After the cultured cells were treated with 12 μmol/L 5-azacytidine （5- aza） one week, the cells gradually increased in size, lengthened in one direction and formed a stick-like morphology. The cells were fused with adjoining cells when they were cultured in 5-aza medium for two weeks and formed my- otube-like structures at the third week. The results from RT-PCR assay showed that MBC isolated from BMNC expressed α-skeletal actin, desmin and MEF-2D, and after the treatment with 5-aza they expressed β-MHC and GA- TA4. The α-actin was expressed either with or without the 5-aza treatment,and myosin was detected by Western blot after the treatment. Similar results were obtained by immunofluoresence, the cells expressed a-actin in the whole cells both with or without the treatment and myosin was expressed in the cytoplasm only after the treatment. The results indicated that MSCs origined from BMSCs have patential to differentiated into cardiomyocytes, and the stage of differ- entiated cells was between cadiomyocyte progenitor and differentiated cardiomyocytes. Our work provided a useful source of cardiomyocyte progenitor for the cell transplantation therapy for heart failure.