Gata4 Blocks Somatic Cell Reprogramming By Directly Repressing Nanog

Abstract

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 Disclosure of potential conflicts of interest is found at the end of this article.

Epithelioid peritoneal mesothelioma: a hybrid phenotype within a mesenchymal-epithelial/epithelial-mesenchymal transition framework

“…Pluripotent stem cell array analysis of the frozen material also used for the WB experiments revealed three factors in a ground state and therefore characteristics of CSCs: VEGFR2, which was expressed in E-MpM; E-cadherin, a MErT/EMT regulator that was shared by E-MpMs and S-MpMs despite its irrelevant immunophenotypical expression in S-MpMs; and GATA4, a lineage control transcription factor that activates or represses depending on the cell context [40, 41] and was restricted to two E-MpM cases (#14 and #15, Table 1, Figure 2D). …”

Early development of porcine parthenogenetic embryos and reduced expression of primed pluripotent marker genes under the effect of lysophosphatidic acid

“…Serrano et al. () showed coexpression of GATA4 with OCT4 , KLF4 and SOX2 in mouse embryonic fibroblasts greatly impaired reprogramming, which describe the negative 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 and decreasing the GATA4 expressing could increase the pluripotency. The activation of GATA4 in ES cells is known to drive their differentiation to endoderm (Oda et al., ).…”

“…Our results also show the addition of LPA decreased that of hypoblast marker gene GATA4. Serrano et al (2013) Note. Embryos were cultured in medium containing PBS (1:1000) or LPA (10, 50, 100 μM) postactivation.…”

Mechanisms for enhancing cellular reprogramming

“…The ability of maternal factors to enhance reprogramming may reflect the potent ability of oocytes to reprogram somatic cells. It is important to note that pioneer factors also appear to interfere with OSKM and counteract their induction to pluripotency, once co-expressed with OSKM [39,40]. Remarkably, these interfering factors extensively co-bind with OSKM [39].…”

“…Remarkably, these interfering factors extensively co-bind with OSKM [39]. For example, Gata4 can replace Oct4 in reprogramming, yet Gata4 blocks reprogramming if co-expressed with OSKM [24,40]. This indicates that OSKM substitutes engage the somatic genome by binding many overlapping targets, creating alternative, yet conflicting, routes to pluripotency.…”