The pluripotency transcription factor Nanog represses glutathione reductase gene expression in mouse embryonic stem cells

Abstract

Objective Redox homeostasis maintenance is essential to bring about cellular functions. Particularly, embryonic stem cells (ESCs) have high fidelity mechanisms for DNA repair, high activity of different antioxidant enzymes and low levels of oxidative stress. Although the expression and activity of antioxidant enzymes are reduced throughout the differentiation, the knowledge about the transcriptional regulation of genes involved in defense against oxidative stress is yet restricted. Since glutathione is a central component of a complex system involved in preserving cellular redox status, we aimed to study whether the expression of the glutathione reductase (Gsr) gene, which encodes an essential enzyme for cellular redox homeostasis, is modulated by the transcription factors critical for self-renewal and pluripotency of ESCs. Results We found that Gsr gene is expressed in ESCs during the pluripotent state and it was upregulated when these cells were induced to differentiate, concomitantly with Nanog decreased expression. Moreover, we found an increase in Gsr mRNA levels when Nanog was downregulated by a specific shRNA targeting this transcription factor in ESCs. Our results suggest that Nanog represses Gsr gene expression in ESCs, evidencing a role of this crucial pluripotency transcription factor in preservation of redox homeostasis in stem cells. Electronic supplementary material The online version of this article (10.1186/s13104-019-4411-0) contains supplementary material, which is available to authorized users.

AKT1 induces Nanog promoter in a SUMOylation-dependent manner in different pluripotent contexts

“…2D and E. The efficacy of each shRNA showed a significant reduction in the expression of each of the TFs evaluated compared to the shGFP (Additional file 1: Figure S5), similar to our previous works [51][52][53][54][55][56][57]. Surprisingly, none of the shRNA targeting Oct4, Sox2 or Nanog, modified the previously reported response of the Nanog promoter to AKT compared to the control shRNA (Fig.…”

The pluripotency transcription factor OCT4 represses heme oxygenase‐1 gene expression

“…2A). All shRNA encoding vectors have been previously used [28][29][30]38,39,41] and were highly effective in silencing the respective TF (Fig. 2B).…”

“…However, the relationship between pluripotency TFs and the components of the oxidative stress defense systems remains poorly explored. We have previously found that OCT4, SOX2, and NANOG regulate the expression of Sod1, Sod2, and Gsr [28–30], revealing a regulatory link between pluripotency TFs and the antioxidant system. In this work, we found that the pluripotency TF OCT4 represses the Hmox1 gene, demonstrating a meaningful connection between the pluripotency core and this system.…”

“…We have previously reported evidence of a regulatory relationship between components of the antioxidant cell system and pluripotency TFs in ES cells. We found that OCT4, SOX2, and NANOG, essential TFs for selfrenewal and pluripotency maintenance [26,27], regulate the expression of relevant genes involved in oxidative stress defense, specifically by inducing superoxide dismutases 1 and 2 (Sod) genes [28,29], and by transcriptionally repressing glutathione reductase (Gsr) [30].…”

The FOXO signaling axis displays conjoined functions in redox homeostasis and stemness

“…GSH, in turn, can be regenerated from its oxidized disulfide form (GSSG) by glutathione reductase (GR) using reduced nicotinamide adenine dinucleotide phosphate (NADPH) as an electron donor. In PSCs glutathione reductase is increased throughout ESC differentiation [ 142 ]. However, it is not clear whether the increase in GR expression precedes differentiation initiation, or whether GR activation is a byproduct of the switch to OxPhos.…”