Abstract
Embryonic stem cells (ESCs) fluctuate among different levels of pluripotency defined as metastates. Sporadically, metastable cellular populations convert to a highly pluripotent metastate that resembles the preimplantation two-cell embryos stage (defined as 2C stage) in terms of transcriptome, DNA methylation, and chromatin structure. Recently, we found that the retinoic acid (RA) signaling leads to a robust increase of cells specifically expressing 2C genes, such as members of the Prame family. Here, we show that Gm12794c, one of the most highly upregulated Prame members, and previously identified as a key player for the maintenance of pluripotency, has a functional role in conferring ESCs resistance to RA signaling. In particular, RA-dependent expression of Gm12794c induces a ground state-like metastate, as evaluated by activation of 2C-specific genes, global DNA hypomethylation and rearrangement of chromatin similar to that observed in naive totipotent preimplantation epiblast cells and 2C-like cells. Mechanistically, we demonstrated that Gm12794c inhibits Cdkn1A gene expression through the polycomb repressive complex 2 (PRC2) histone methyltransferase activity. Collectively, our data highlight a molecular mechanism employed by ESCs to counteract retinoic acid differentiation stimuli and contribute to shed light on the molecular mechanisms at grounds of ESCs naive pluripotency-state maintenance.
Highlights
Embryonic stem cells (ESCs) colonies are characterized by different metastable sub-populations marked by the presence of specific factors whose expression profoundly affects the state of cells pluripotency [1,2,3,4,5,6]
Confocal immunofluorescence analysis showed that Gm12794c-expressing cells (Gm+) presented higher levels of H3K27ac compared with the Gm12794c-negative cells (Gm −), both in the presence (Fig. 3a, I) and the absence of RA (Supplementary Fig. 6, full bars), while no significant difference was observed when we investigated H3K27me3 levels, despite the trend favoring a retinoic acid-dependent increased tri-methylation (Fig. 3a, II; Supplementary Fig. 6)
As nicely shown in the study of Sheppard et al [50], depending on residues in the neighborhood, nuclear receptors (NRs) boxes show different levels of interaction to Precisely orchestrated and dynamic processes define early phases of animal development that upon specific differentiation stimuli lead to cell fate specification
Summary
ESCs colonies are characterized by different metastable sub-populations (metastates) marked by the presence of specific factors whose expression profoundly affects the state of cells pluripotency [1,2,3,4,5,6]. Metastable sub-populations may occasionally convert to a highly pluripotent metastate that resembles the two-cell stage (2C) embryos during which an enormous rearrangement of chromatin takes place causing a reprogramming of transcription called zygotic genome activation (ZGA) [7,8,9]. The action of RA hinges on nuclear receptors (NRs), a family of ligand-regulated transcription factors that control a wide range of developmental processes, called retinoic acid receptors (RARs). Human PRAME has been shown to modulate the activity of RAR alpha [22]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
