人孤雌胚胎干细胞与正常胚胎干细胞分化能力的比较

目的 比较人类孤雌胚胎干细胞(pESCs)系与正常胚胎干细胞(nESCs)系的分化能力,探讨pESCs是否和nESCs一样具有多向分化潜能.方法 将pESCs和nESCs分别注射到重症联合免疫缺陷(SCID)小鼠体内形成畸胎瘤,瘤体组织切片和HE染色后进行组织学分析;将pESCs和nESCs体外悬浮培养形成拟胚体(EB),利用RT-PCR检测3个胚层主要器官以及滋养层细胞发育关键基因的表达;将pESCs和nESCs定向诱导分化为滋养层细胞,通过流式细胞仪测定人绒毛膜促性腺激素-β(hCG-β)阳性细胞比例以及通过酶联免疫吸附测定(ELISA)进行hCG-β的定量分析.结果 在体内生长和体外培养过程中,pESCs和nESCs均能够向3个胚层的细胞类型分化.在SCID小鼠体内可形成畸胎瘤,有神经上皮、软骨、腺上皮等3个胚层的衍生物产生;pESCs和nESCs来源的EB在体外自发分化5~21d后,均检测到3个胚层主要器官以及滋养层细胞发育关键基因的表达;pESCs定向分化为滋养细胞后,可以检测到hCG-β的表达,但其阳性细胞比例和分泌量均低于nESCs.结论 pESCs具有向3个胚层以及滋养层细胞分化的能力,但是向滋养层细胞分化的能力仍低于nESCs.

Comparison of the differentiation capability between human parthenogenetic embryonic stem cells and normal embryonic stem cells

Objective The differentiation capability of human parthenogenetic embryonic stem cells (pESCs) and normal embryonic stem cells (nESCs) was compared to estimate whether the pluripotent potential of pESCs was equal to that of nESCs. Methods pESCs and nESCs were injected into the rear leg of mice with severe combined immunodeficiency disease (SCID) to form teratoma, which was then processed for histological analysis by HE staining; pESCs and nESCs were detached to grow as aggregates in suspension to form embryoid body (EB), which were collected for the analysis of the key genes expression related with the development of main organs from all three germ layers and trophoblast using RT-PCR. Further, pESCs and nESCs were induced to differentiate into trophoblasts and detected the human chorionic gonadotrophin-β(hCG-β) content in the culture medium by ELISA as well as the percentage of hCG-β positive cells by flow cytometry. Results pESCs and nESCs can differentiate into the cell types from three germ layers both EM>in vivo/EM> andEM>in vitro/EM> differentiation assay. pESCs and nESCs were able to form teratomas with a complex pattern of differentiation to three germ layers, such as neural epithelia, cartilage and glandular epithelium. The key genes related with the development of main organs from all three germ layers and tropoblast were expressed in day 5 and day 21 EB from pESCs and nESCs. pESCs can be induced to differentiate into trophoblasts and expressed hCG-β, but the content of hCG-β and the percentage of hCG-β positive cells were lower in pESCs than that in nESCs. Conclusion pESCs can differentiate into three germ layers and tropoblas