Analysis of Oct4-dependent transcriptional networks regulating self-renewal and pluripotency in human embryonic stem cells
Analysis of Oct4-dependent transcriptional networks regulating self-renewal and pluripotency in human embryonic stem cells
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DOI：
10.1634/stemcells.2006-0426
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发表时间：
2007-02-01
期刊：
影响因子：
5.2
通讯作者：
Adjaye, James
中科院分区：
文献类型：
--
作者：
Babaie, Yasmin;Herwig, Ralf;Adjaye, James
POU结构域转录因子OCT4是哺乳动物早期胚胎多能性的关键调节因子，在囊胚的内细胞团中高度表达。与其在维持多能性中的关键作用一致，在滋养层谱系形成过程中，Oct4的表达迅速下调。为了加深我们对人类这一分化事件分子基础的理解，我们采用了一种功能基因组学方法，包括在人类胚胎干细胞系中通过RNA干扰介导抑制OCT4功能，并对产生的转录图谱进行分析，以鉴定人类细胞中依赖OCT4的基因。我们检测到超过1000个基因的表达发生改变，包括受OCT4直接正向调节（NANOG、SOX2、REX1、LEFTB、LEFTA/EBAF、DPPA4、THY1和TDGF1）或负向调节（CDX2、EOMES、BMP4、TBX18、短尾畸形蛋白[T]、DKK1、HLX1、GATA6、ID2和DLX5）的靶基因，以及与OCT4相关的干细胞调节因子SOX2和NANOG的靶基因。我们的数据集包括激活素、骨形态发生蛋白、成纤维细胞生长因子和WNT信号通路的调节因子。这些通路与调节人类胚胎干细胞分化有关，因此进一步验证了我们的分析结果。此外，我们还鉴定了一些差异表达基因，它们涉及表观遗传学、染色质重塑、细胞凋亡和代谢，这可能指向调节人类多能性和滋养层分化的潜在分子机制。该数据集与先前人类胚胎内细胞团和滋养外胚层之间比较的显著一致性表明，体外研究人类胚胎干细胞分化是研究人类早期胚胎分化的一个有用模型。
The POU domain transcription factor OCT4 is a key regulator of pluripotency in the early mammalian embryo and is highly expressed in the inner cell mass of the blastocyst. Consistent with its essential role in maintaining pluripotency, Oct4 expression is rapidly downregulated during formation of the trophoblast lineage. To enhance our understanding of the molecular basis of this differentiation event in humans, we used a functional genomics approach involving RNA interference-mediated suppression of OCT4 function in a human ESC line and analysis of the resulting transcriptional profiles to identify OCT4-dependent genes in human cells. We detected altered expression of > 1,000 genes, including targets regulated directly by OCT4 either positively ( NANOG, SOX2, REX1, LEFTB, LEFTA/ EBAF DPPA4, THY1, and TDGF1) or negatively ( CDX2, EOMES, BMP4, TBX18, Brachyury [ T], DKK1, HLX1, GATA6, ID2, and DLX5), as well as targets for the OCT4- associated stem cell regulators SOX2 and NANOG. Our data set includes regulators of ACTIVIN, BMP, fibroblast growth factor, and WNT signaling. These pathways are implicated in regulating human ESC differentiation and therefore further validate the results of our analysis. In addition, we identified a number of differentially expressed genes that are involved in epigenetics, chromatin remodeling, apoptosis, and metabolism that may point to underlying molecular mechanisms that regulate pluripotency and trophoblast differentiation in humans. Significant concordance between this data set and previous comparisons between inner cell mass and trophectoderm in human embryos indicates that the study of human ESC differentiation in vitro represents a useful model of early embryonic differentiation in humans.