共培养条件下人脐血间充质干细胞抑制心肌细胞凋亡:是否安全有效?(英文)

Human umbilical cord blood-derived mesenchymal stem cells inhibit cardiomyocyte apoptosis under co-culture conditions A safety and efficacy assessment

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-derived mesenchymal stem cells （UCB-MSCs） have been shown to lead to new tissue formation after homing and engrafting to the heart.But the safety of UCB-MSCs engrafting remains to be further investigated.OBJECTIVE：To study the safety and apoptosis inhibition of the UCB-MSCs under co-culture conditions on human cardiomyocytes.METHODS：UCB was collected at delivery with informed consent obtained from 10 donors.The UCB-MSCs were treated with 5-azaserine to induce differentiation into cardiomyocytes.The in vitro cultured cells of the 3rd-5th passages and dividing cells were taken to detect telomerase activity,tumor-related gene expression,G-banding patterns of chromosomal karyotupes,cell surface antigen expression,tumor formation in nude mice,and inhibited apoptosis under co-culture conditions.RESULTS AND CONCLUSION：Prior to and after 5-azaserine induction,telomerase activity and tumor-related gene expression （p53,cyclin A,cdk2,β-actin,C-fos,h-TERT,c-myc） of UCB-MSCs were similar,no abnormal chromosomal karyotupes were observed,immunophenotype exhibited no change,CD34 was negative,but CD44 and CD90 （Thy-1） were positive.At 10 weeks after inoculation of UCB-MSCs,nude mice still survived healthily and no formed tumor in vivo was observed.Hematoxylin-eosin staining suggested normal subcutaneous tissue.Compared with simple cardiomyocytes,UCB-MSCs could significantly inhibit cardiomyocyte apoptosis under co-culture conditions （P 0.05）,indicating that human UCB-MSCs are a valuable,safe,and effective source of cell transplantation treatment.