Esrrb plays important roles in maintaining self-renewal of trophoblast stem cells (TSCs) and reprogramming somatic cells to induced TSCs

Abstract

Trophoblast stem cells (TSCs), which can be derived from the trophoectoderm of a blastocyst, have the ability to sustain self-renewal and differentiate into various placental trophoblast cell types. Meanwhile, essential insights into the molecular mechanisms controlling the placental development can be gained by using TSCs as the cell model. Esrrb is a transcription factor that has been shown to play pivotal roles in both embryonic stem cell (ESC) and TSC, but the precise mechanism whereby Esrrb regulates TSC-specific transcriptome during differentiation and reprogramming is still largely unknown. In the present study, we elucidate the function of Esrrb in self-renewal and differentiation of TSCs, as well as during the induced TSC (iTSC) reprogramming. We demonstrate that the precise level of Esrrb is critical for stem state maintenance and further trophoblast differentiation of TSCs, as ectopically expressed Esrrb can partially block the rapid differentiation of TSCs in the absence of fibroblast growth factor 4. However, Esrrb depletion results in downregulation of certain key TSC-specific transcription factors, consequently causing a rapid differentiation of TSCs and these Esrrb-deficient TSCs lose the ability of hemorrhagic lesion formation in vivo. This function of Esrrb is exerted by directly binding and activating a core set of TSC-specific target genes including Cdx2, Eomes, Sox2, Fgfr4, and Bmp4. Furthermore, we show that Esrrb overexpression can facilitate the MEF-to-iTSC conversion. Moreover, Esrrb can substitute for Eomes to generate GEsTM-iTSCs. Thus, our findings provide a better understanding of the molecular mechanism of Esrrb in maintaining TSC self-renewal and during iTSC reprogramming.

Reprogramming epiblast stem cells into pre-implantation blastocyst cell-like cells

“…Top-right and bottom panels: average regulon activity at single-cell level in RGB color for pluripotency regulons (red), PE regulons (green), and TE regulons (blue) across the tSNE plot. (D) Heatmap (pheatmap) of row-clustered TE/TSC signatures and PE/XEN signatures of reprogramming and model cells from this study and others ( Benchetrit et al., 2019 ; Gao et al., 2018 ; Huang et al., 2020 ; Parenti et al., 2016 ; Posfai et al., 2021 ). Yellow outline surrounds the model cells (e.g., TE/TSC and PE/XEN), and cells outside the box are experimental (e.g., iTE/GETSM_TSC and cXEN/iPE/iXEN).…”

Differential Transcriptomes and Methylomes of Trophoblast Stem Cells From Naturally-Fertilized and Somatic Cell Nuclear-Transferred Embryos

“…The network was partially shared by the pluripotency network in ESCs. The TFs in network ESRRB, SOX2, and NR0B1 were reported to confer the pluripotency of ESCs ( Adachi et al, 2013 ; Gao H. et al, 2018 ). However, the TFs ZFP281 and ELF5 are specifically related to TSC stemness ( Gao H. et al, 2018 ; Ishiuchi et al, 2019 ).…”

“…The derivation of TSCs was performed as published before ( Gao H. et al, 2018 ). In brief, we transferred E4.5 blastocysts onto MMC-treated MEFs and first culture in TSC medium composed of 70% FCM, 30% TSM, and 1× F4H medium (TSM: RPMI1640 supplemented with 20% FBS, 1 mM sodium pyruvate, 100 μM β-mercaptoethanol, and 2 mM L-glutamine; 1× F4H: 25 ng/ml of FGF4, and 1 μg/ml of heparin).…”

Chromatin Regulation in Development: Current Understanding and Approaches

“…This approach opens up a new aspect to further elucidate the mechanisms and regulators of mTSC lineage specification [ 77 ]. Additionally, it has been proposed that ESRRB could directly regulate the core genes of the TSC self-renewal regulatory network such as CDX2 , EOMES , and SOX2 [ 78 ]. Members of the ERV family RLTR13D5 could also act as enhancers; they are bound by H3K4me1 and H3K27ac, therefore providing binding sites for CDX2 , EOMES , and ELF5 [ 79 ].…”