Activation of GSK3β by Sirt2 Is Required for Early Lineage Commitment of Mouse Embryonic Stem Cell

Abstract

Sirt2, a member of the NAD+-dependent protein deacetylase family, is increasingly recognized as a critical regulator of the cell cycle, cellular necrosis and cytoskeleton organization. However, its role in embryonic stem cells (ESCs) remains unclear. Here we demonstrate that Sirt2 is up-regulated during RA (retinoic acid)-induced and embryoid body (EB) differentiation of mouse ESCs. Using lentivirus-mediated shRNA methods, we found that knockdown of Sirt2 compromises the differentiation of mouse ESCs into ectoderm while promoting mesoderm and endoderm differentiation. Knockdown of Sirt2 expression also leads to the activation of GSK3β through decreased phosphorylation of the serine at position 9 (Ser9) but not tyrosine at position 216 (Tyr216). Moreover, the constitutive activation of GSK3β during EB differentiation mimics the effect of Sirt2 knockdown, while down-regulation of GSK3β rescues the effect of Sirt2 knockdown on differentiation. In contrast to the effect on lineage differentiation, Sirt2 knockdown and GSK3β up-regulation do not change the self-renewal state of mouse ESCs. Overall, our report reveals a new function for Sirt2 in regulating the proper lineage commitment of mouse ESCs.

Metabolic control of primed human pluripotent stem cell fate and function by the miR-200c–SIRT2 axis

“…1h,i). Our results are in agreement with previous studies showing downregulation of SIRT1 during hESC differentiation 29,30 and upregulation of SIRT2 during mouse ESC differentiation 31 .…”

“…In agreement with our results, previous studies showed upregulation of SIRT1 in hPSCs 29,30 and SIRT1’s important roles for generation of mouse iPSCs 30,37 . In addition, the study by Si et al 31 showed that SIRT2 is upregulated during in vitro differentiation of mouse ESCs and SIRT2KD promotes mesoderm and endoderm lineages while compromising ectoderm differentiation. In contrast, our results show that SIRT2 regulates more fundamental stem cell functions such as metabolism, cell survival/death, and pluripotent differentiation potential in hPSCs.…”

Glycogen synthase kinase-3 (GSK3): Regulation, actions, and diseases

“…There is also evidence that members of the sirtuin (Sirt) family of deacetylases regulate GSK3. Sirt2 activity is associated with inhibition of GSK3 (Dan et al, 2012; Si et al, 2013), whereas Sirt1 has been reported to either activate (Monteserin-Garcia et al, 2013) or inhibit (Li et al, 2013) GSK3. GSK3 also modulates post-translational modifications of histones by regulating several histone acetyltransferases (HATs).…”

Energy Metabolism Regulates Stem Cell Pluripotency

“…Although glycolytic flux is common across all stages of pluripotency, the relative contributions of glycolysis versus OxPhos do vary. The primed pluripotent state of hPSCs and mEpiSCs is almost exclusively glycolytic (Tesar et al, 2007;Nichols and Smith, 2009;Takashima et al, 2014;Theunissen et al, 2014), whereas naïve hPSCs and mESCs utilize a bivalent metabolic system with a greater reliance on oxidative metabolism (Lee et al, 2012;Zhou et al, 2012;Si et al, 2013;Mu et al, 2015;Cha et al, 2017). Indeed, early preparatory phase glycolytic metabolites such as fructose 1, 6-bisphosphate are enriched in primed PSCs without accumulation of downstream metabolites, suggesting that these glycolytic intermediates may be consumed for anabolism or one-carbon metabolism (Tesar et al, 2007;Zhou et al, 2012;Gafni et al, 2013;Takashima et al, 2014;Sperber et al, 2015).…”