Gata4 Blocks Somatic Cell Reprogramming By Directly Repressing Nanog
Gata4 Blocks Somatic Cell Reprogramming By Directly Repressing Nanog
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DOI：
10.1002/stem.1272
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发表时间：
2013-01-01
期刊：
影响因子：
5.2
通讯作者：
Bort, Roque
中科院分区：
文献类型：
--
作者：
Serrano, Felipe;Calatayud, Carles F.;Bort, Roque
体细胞可以通过四种因子Oct 4、Klf 4、Sox 2和Myc的异位表达重编程为诱导多能干（iPS）细胞。在这里，我们研究了Gata 4在重编程过程中的作用，并提出了这个转录因子家族在诱导多能性中的负面作用的证据。在小鼠胚胎成纤维细胞中，Gata 4与Oct 4、Klf 4和Sox 2（有或没有Myc）的共表达极大地损害了重编程和内源性Nanog表达。Nanog上调的缺乏与从重编程的起始阶段到iPS细胞的完全多能状态特征的过渡中的阻断相关。向重编程混合物中添加Nanog阻断了Gata 4表达所观察到的有害作用。在重编程期间通过短发夹RNA下调内源性Gata 4既加速又增加了该过程的效率，并且增加了内源性Nanog的mRNA水平。使用比较基因组学，我们确定了一个共识的结合位点加塔因子在进化保守区位于9 kb的Nanog基因上游。使用染色质免疫沉淀，凝胶阻滞和荧光素酶测定，我们发现Gata 4结合到这个区域，并抑制小鼠胚胎干细胞中的Nanog转录。总的来说，我们的研究结果首次描述了Gata 4在体细胞重编程中的负面影响，并强调了加塔因子在控制早期胚胎细胞谱系选择的转录网络中的作用。干细胞2013;31：71-82
Somatic cells can be reprogrammed to induced pluripotent stem (iPS) cells by ectopic expression of the four factors Oct4, Klf4, Sox2, and Myc. Here, we investigated the role of Gata4 in the reprogramming process and present evidence for a negative role of this family of transcription factors in the induction of pluripotency. Coexpression of Gata4 with Oct4, Klf4, and Sox2 with or without Myc in mouse embryonic fibroblasts greatly impaired reprogramming and endogenous Nanog expression. The lack of Nanog upregulation was associated with a blockade in the transition from the initiation phase of reprogramming to the full pluripotent state characteristic of iPS cells. Addition of Nanog to the reprogramming cocktail blocked the deleterious effects observed with Gata4 expression. Downregulation of endogenous Gata4 by short hairpin RNAs during reprogramming both accelerated and increased the efficiency of the process and augmented the mRNA levels of endogenous Nanog. Using comparative genomics, we identified a consensus binding site for Gata factors in an evolutionary conserved region located 9 kb upstream of the Nanog gene. Using chromatin immunoprecipitation, gel retardation, and luciferase assays, we found that Gata4 bound to this region and inhibited Nanog transcription in mouse embryonic stem cells. Overall, our results describe for first time the negative effect of Gata4 in the reprogramming of somatic cells and highlight the role of Gata factors in the transcriptional networks that control cell lineage choices in the early embryo. STEM CELLS 2013;31:71-82