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通过人胚胎干细胞(Human embryonic stemcells,hESCs)经体内分化获取间充质干细胞(Mesenchymal stem cells,MSCs)为人胚胎干细胞提供一种新的滋养层。将约5×106个hESCs注射入重症免疫联合缺陷小鼠形成畸胎瘤,8周后再从畸胎瘤中分离MSCs并鉴定,将MSCs作为hESCs的滋养层细胞,并检测和观察hESCs的生长情况、细胞特性和分化能力。从畸胎瘤中获得了纯度较高的具有类似骨髓来源的MSC特性的细胞群,其形态相似、表面抗原标志相似(CD34和CD45阴性,CD29、CD49b、CD105、CD73和CD90阳性),经诱导可以向成骨细胞和成脂细胞分化。将hESCs在MSCs滋养层细胞上传代培养10代以上,hESCs依然具有正常的细胞形态,反转录PCR证实其特异转录因子Oct4、Nanog的表达,干细胞表面标记SSEA-1显示为阴性,SSEA-4、TRA-1-60、TRA-1-81显示为阳性,碱性磷酸酶染色显示为阳性,并且核型正常。体外EB形成和体内畸胎瘤形成证明了其全能性。因此来源于hESCs本身的MSCs可以被用来作为支持胚胎干细胞生长并维持其未分化状态的滋养层细胞。
Mesenchymal stem cells (MSCs) obtained from human embryonic stem cells (hESCs) differentiate into human embryonic stem cells (MSCs) to provide a new trophoblast. Approximately 5 × 106 hESCs were injected into severe teratogenic mice to form teratocarcinoma. MSCs were isolated from teratomas and identified 8 weeks later. MSCs were used as feeder cells of hESCs, and the growth of hESCs was detected and observed Condition, cell character and differentiation ability. From the teratoma cells were obtained with similar purity and bone marrow-derived MSC characteristics. The morphology was similar and the surface antigen markers were similar (CD34 and CD45 negative, positive for CD29, CD49b, CD105, CD73 and CD90) It can differentiate into osteoblasts and adipocytes. HESCs were cultured on feeder cells of MSCs for more than 10 generations, hESCs still had normal cell morphology. Reverse transcriptase PCR confirmed the expression of specific transcription factors Oct4 and Nanog, SSEA-1 of stem cells showed negative, SSEA-4 , TRA-1-60, TRA-1-81 showed positive, alkaline phosphatase staining showed positive, and karyotype was normal. EB formation in vitro and in vivo teratoma formation demonstrate its pluripotency. Thus, MSCs derived from hESCs themselves can be used as trophoblast cells that support the growth of embryonic stem cells and maintain their undifferentiated state.