目的:研究人诱导多能干细胞(induced pluripotent stem cells,iPS)自然分化过程中上皮-间质转化(epithelial-mes-enchymal transition,EMT)的变化过程。方法按常规方法iPS细胞接种于单层饲养层细胞上培养并传代,通过EB的方式令iPS细胞自然分化,收集未分化的iPS细胞以及分化7d、14d、21d和28d的细胞,采用RT-PCR和Western Blot方法检测EMT相关基因及蛋白的表达水平。结果 RT-PCR和Western Blot结果表明,未分化人iPS细胞可见E-cadherin基因和蛋白的表达,分化后E-cadherin的表达明显减少,而N-cadherin基因和蛋白在细胞未分化时均未见表达,发生分化后表达明显上调;在人iPS细胞分化过程中,Snail和Slug转录因子以及蛋白都明显发生上调。结论人iPS细胞自然分化与EMT,即E-cadherin和N-cadherin转化有关。
Objective To investigate whether the differentiation of induced pluripotent stem cells (iPS) is associated with the presence of epithelial-mesenchymal transition (EMT). Methods Human iPS cells were maintained in an undifferentiated state by culture in iPS cells medium in the presence of a fibroblast feeder layer, and were differentiated in EB cells medium. IPS cells dif-ferentiated for 0, 7, 14, 21, and 28 d were collected, and detected EMT associated genes and proteins by RT-RCR and western blot analysis. Results E-cadherin gene and protein were detected in undifferentiated human iPS cells, lower levels protein was ob-served following induction of differentiation. In contrast, N-cadherin gene and protein were absent in undifferentiated human iPS cells and subsequently detected following differentiation of the cells. Undifferentiated human iPS cells lacked transcripts encoding Slug and exhibited low levels of Snail transcripts. Upon differentiation both Snail and Slug transcripts were increased. Conclusion EMT event occurs during Human iPS cells differentiation.