环境决定命运

iseeyou1210

1.主题:从成纤维细胞直接重编程为外胚层干细胞----环境决定命运
0 j+ D: I" p& r% r4 h2. 原文主题: Direct reprogramming of fibroblasts into epiblast stem cells4 H* F6 T5 T. M, f' w8 i
3. 摘要翻译: Epiblast stem cells (外胚层干细胞)来源于受精卵着床以后的外胚层组织,这些干细胞具备全能型, 畸胎瘤形成实验显示这些干细胞可以形成3种胚层.近期,通过在体细胞中表达四因子(Oct4, Sox2, Klf4 和c-Myc) 可以诱导形成多能干细胞,并且这些细胞和正常的胚胎干细胞在很多的特征上是一致的.  到目前为止, 还没有直接将体细胞诱导成外胚层干细胞的报道.在这篇文章中,作者应用了同样的四个因子,采用特殊的外胚层干细胞的培养条件,成功地诱导体细胞, 造就出在形态,基因表达,表观遗传学特征和嵌合体形成能力等方面和自然外胚层干细胞类似的诱导型外胚层干细胞.本研究的意义在于作者提出了在重新编程过程中,体外的培养环境决定了细胞重编程的命运.因此,作者们提出了一个大胆的假设,这就是可以通过改变培养条件来生产出不同(组织)的干细胞群体.9 o* P0 \6 N* }
9 m2 [$ N+ `, L5 l
4. 原文摘要: Epiblast stem cells (EpiSCs) derived from epiblast tissue of post-implantation embryos are pluripotent and can give rise to all three germ layers in teratoma assays1, 2. Introduction of the four transcription factors Oct4, Sox2, Klf4 and c-Myc into somatic cells has been shown to generate induced pluripotent stem cells (iPSCs) that are very similar to embryonic stem cells (ESCs) in a number of characteristics3, 4, 5, 6. However, generation of EpiSCs by the direct reprogramming of somatic cells using these transcription factors has not been shown to date. Here, we show that these transcription factors can be used to directly generate induced EpiSCs (iEpiSCs) under EpiSC culture conditions. iEpiSCs resemble EpiSCs in morphology, gene expression pattern, epigenetic status and chimaera-forming capability. This study demonstrates that the culture environment in transcription factor-mediated reprogramming determines the cell fate of the reprogrammed cell. We therefore hypothesize that it will eventually be possible to shape the identity of a directly reprogrammed cell simply by modulating culture conditions.
9 ]0 u4 x  b& Z6 g; [( G5.原文下载: http://www.nature.com/ncb/journal/v13/n1/abs/ncb2136.html, {% h. c2 p: K
1 A% n3 S$ {  I. I
6. 个人翻译,不恰当之处请指正!
9 J9 G' `5 A4 r! m$ V# ~