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背景:脐血间充质干细胞归巢或植入心脏后能够修复心肌组织,但其移植治疗的安全性尚有待分析。目的:观察共培养情况下人脐血间充质干细胞能否抑制人心肌细胞凋亡,以及人脐血间充质干细胞移植治疗的安全性。方法:人脐血间充质干细胞来源于分娩孕妇脐血,经5-氮杂胞苷处理24h向心肌细胞诱导分化。分别取体外培养3～5代细胞以及诱导后细胞,检测其端粒酶活性及肿瘤相关基因的表达、染色体核型G带分型、细胞表面抗原表达、裸鼠体内成瘤情况、共培养条件下细胞凋亡情况。结果与结论:脐血间充质干细胞经5-氮杂胞苷诱导前后,其端粒酶活性及p53,cyclinA,cdk2,β-actin,C-fos,h-TERT,c-myc等肿瘤相关基因的表达均基本相似;均未发现异常染色体核型;免疫表型无明显变化,CD34呈阴性,CD44及CD90(Thy-1)呈阳性。脐血间充质干细胞接种10周后裸鼠仍健康存活,体内未见肿瘤生长,石蜡切片苏木精-伊红染色显示为正常的皮下组织。与单纯心肌细胞比较,共培养情况下脐血间充质干细胞能够显著抑制心肌细胞的凋亡(P<0.05),提示人脐血间充质干细胞用于细胞移植治疗安全有效。
Background: Umbilical cord blood mesenchymal stem cells can repair myocardial tissue after homing or implantation into the heart. However, the safety of the transplantation therapy remains to be analyzed. Objective: To observe whether human umbilical cord blood mesenchymal stem cells can inhibit apoptosis of human cardiomyocytes and the safety of human umbilical cord blood mesenchymal stem cell transplantation under co-culture. Methods: Human umbilical cord blood derived mesenchymal stem cells derived from cord blood of pregnant women and induced by 5-azacytidine to differentiate into cardiomyocytes. The cells were cultured in vitro for 3-5 passages, and the cells were induced to detect the telomerase activity and the expression of tumor related genes. The genotypes of G - band, the expression of cell surface antigen, the tumorigenesis in nude mice, the co - culture conditions Under the condition of apoptosis. RESULTS AND CONCLUSION: Telomerase activity and the expression of p53, cyclin A, cdk2, β-actin, C-fos, h-TERT and c-myc in umbilical cord blood mesenchymal stem cells before and after induction by 5-azacytidine The expression of CD44 and CD90 were all similar. No abnormal chromosome karyotype was found. There was no significant change in the immunophenotype. CD34 was negative and CD44 and CD90 (Thy-1) were positive. Nude mice survived 10 weeks after inoculation of umbilical cord blood-derived mesenchymal stem cells, no tumor growth in vivo, paraffin sections of hematoxylin-eosin staining showed normal subcutaneous tissue. Compared with simple cardiomyocytes, UCB-MSCs could significantly inhibit cardiomyocyte apoptosis (P <0.05), suggesting that human umbilical cord blood-derived mesenchymal stem cells were safe and effective for cell transplantation.