人类胚胎干细胞体外分化形成包含多种细胞的类胚体

目的:研究人类胚胎干细胞的体外多向分化能力.方法:胚胎干细胞在无饲养细胞、无碱性成纤维细胞生长因子(bFGF)、悬浮条件下培养形成类胚体.采用RT-PCR方法检测不同培养时间类胚体中某些功能细胞的特征分子标志.结果:在无饲养细胞、无bFGF、悬浮条件下培养,胚胎干细胞自动聚集形成细胞团,逐渐长大并分化为囊实性类胚体.RT-PCR显示,类胚体表达多种细胞前体及功能细胞的分子标志,如神经前体细胞、胰岛前体细胞以及成熟神经细胞、表达胰岛素的β细胞、表达胰高血糖素的α细胞和肝细胞等等.不同细胞标志在类胚体中出现的时间段有差异,先出现分化程度低的前体细胞分子标志,然后出现成熟细胞的分子标志.结论:人类胚胎干细胞体外可自然分化为表达多种细胞标志的类胚体,是进行深入体外诱导分化研究的基础.

Human embryonic stem cells forming embryoid bodies comprising multiple types of cells

Objective:To investigate the pluripotency of human embryonic stem cells in vitro.Meth-ods:Human embryonic stem cells were cultured in suspension without feeder layers and bFGF in medi-um.mRNAs of different types of cells were analyzed by RT-PCR.Results:When Human embryonicstem cells were cultured in suspension without feeder layers and bFGF in medium,they formed floatingaggregates termed embryoid bodies(EBs),in which many precursors and functional cells were detectedby RT-PCR,such as neural and islet precursors,neurons,insulin-secreting cells,glucagon-secretingcells and liver cells et al.Conclusion:Human embryonic stem cells are able to form embryoid bodiesnaturally in vitro which express specific markers of many types of precursors and mature functional cells.