Project description:Elf5 is a transcription factor with pivotal roles in the trophoblast compartment where it reinforces a trophoblast stem cell (TSC)-specific transcriptional circuit. However, Elf5 is also present in differentiating trophoblast cells that have ceased to express other TSC genes such as Cdx2 and Eomes. In the current study we aimed to elucidate the context-dependent role of Elf5 at the interface between TSC self-renewal and onset of differentiation. We demonstrate that precise levels of Elf5 are critical for normal expansion of the TSC compartment and embryonic survival, as Elf5 overexpression triggers precocious trophoblast differentiation. Through integration of protein interactome, transcriptome and genome-wide chromatin immunoprecipitation data we reveal that this abundance-dependent function is mediated through a shift in preferred Elf5 binding partners; in TSCs, Elf5 interaction with Eomes recruits Tfap2c to triply occupied sites at TSC-specific genes driving their expression. By contrast, the Elf5 and Tfap2c interaction becomes predominant as their protein levels increase. This triggers binding to double and single occupancy sites that harbour the cognate Tfap2c motif, causing activation of the associated differentiation-promoting genes. These data place Elf5 at the centre of a stoichiometry-sensitive transcriptional network where it acts as molecular switch governing the balance between TSC proliferation and differentiation.
Project description:This dataset is part of a study that aims to compare in vivo human trophoblast differentiation into EVTs to different in vitro trophoblast organoids using single-cell and single-nuclei RNA sequencing. This specific dataset includes scRNA-seq and snRNA-seq data from trophoblast stem cells (TSCs). Trophoblast stem cell (TSC) lines BTS5 and BTS11 derived by Okae and colleagues were grown as described previously (Okae et al. 2018) together with EVT differentiation media. This study shows that the main regulatory programs mediating EVT invasion in vivo are preserved in in vitro models of EVT differentiation from primary trophoblast organoids and trophoblast stem cells. Data for primary trophoblast organoids is available under E-MTAB-12650.
Project description:Alternative splicing (AS) is a key process underlying the expansion of proteomic diversity and the regulation of gene expression. However, the contribution of AS to the control of embryonic stem cell (ESC) pluripotency is not well understood. Here, we identify an evolutionarily conserved ESC-specific AS event that changes the DNA binding preference of the forkhead family transcription factor FOXP1. We show that the ESC-specific isoform of FOXP1 stimulates the expression of transcription factor genes required for pluripotency including OCT4, NANOG, NR5A2 and GDF3, while concomitantly repressing genes required for ESC differentiation. Remarkably, this isoform also promotes the maintenance of ESC pluripotency and the efficient reprogramming of somatic cells to induced pluripotent stem cells. These results reveal an AS switch that plays a pivotal role in the regulation of pluripotency through the control of critical ESC-specific transcriptional programs. Protein binding microarray (PBM) experiments were performed for two isoforms of the DNA binding domain of the human FOXP1 gene. Briefly, the PBMs involved binding GST-tagged DNA-binding proteins to two double-stranded 4*44K Agilent microarrays, each containing a different DeBruijn sequence design, in order to determine their sequence preferences. The method is described in Berger et al., Nature Biotechnology 2006.
Project description:Chromatin-associated RNAs have diverse roles in the nucleus. However, their mechanisms of action are poorly understood, in part due to the inability to identify proteins that specifically associate with chromatin-bound RNAs. Here, we address this problem for a subset of chromatin-associated RNAs that form R-loops—RNA-DNA hybrid structures that include a displaced strand of single-stranded DNA. R-loops generally form co-transcriptionally and have important roles in regulation of gene expression, immunoglobulin class switching, and other processes. However, unresolved R-loops can lead to DNA damage and chromosome instability. To identify factors that may bind and potentially regulate R-loop accumulation or mediate R-loop-dependent functions, we used a comparative immunoprecipitation/mass spectrometry approach, with and without RNA-protein crosslinking, to identify a stringent set of R-loop-binding proteins in mouse embryonic stem cells. We identified 365 R-loop-interacting proteins, which were highly enriched for proteins with predicted RNA-binding functions. We characterized several R-loop-interacting proteins of the DEAD-box family of RNA helicases and found that these proteins localize to the nucleolus and, to a lesser degree, the nucleus. Consistent with their localization patterns, we found that these helicases are required for ribosomal RNA processing and regulation of gene expression. Surprisingly, depletion of these helicases resulted in misregulation of highly overlapping sets of protein-coding genes, including many genes that function in differentiation and development. We conclude that R-loop-interacting DEAD-box helicases have non-redundant roles that are critical for maintaining the normal embryonic stem cell transcriptome.
Project description:Human naive pluripotent stem cells have unrestricted lineage potential. Underpinning this property, naive cells are thought to lack chromatin-based lineage barriers. However, this assumption has not been tested. Here, we apply multi-omics to comprehensively define the chromatin-associated proteome, histone post-translational modifications and transcriptome of human naive and primed pluripotent stem cells. Integrating the chromatin-bound proteome and histone modification data sets reveals differences in the relative abundance and activities of distinct chromatin modules, identifying a strong enrichment of Polycomb Repressive Complex 2 (PRC2)-associated H3K27me3 in naive pluripotent stem cell chromatin. Single-cell approaches and human blastoid models reveal that PRC2 activity acts as a chromatin barrier restricting the differentiation of naive cells towards the trophoblast lineage, and inhibiting PRC2 promotes trophoblast fate induction and cavity formation. Our results establish that human naive pluripotent stem cells are not epigenetically unrestricted, but instead possess chromatin mechanisms that oppose the induction of alternative cell fates.
Project description:Genome-wide analysis of histone modification (H2AZ, H3K27ac, H3K27me3, H3K36me3, H3K4me1, H3K4me2, H3K4me3 and H3K9me3), protein-DNA binding (TAF1, P300, Pou5f1 and Nanog), cytosine methylation and transcriptome data in mouse and human ES cells and pig iPS cells We generated histone modification data (H2AZ, H3K27ac, H3K27me3, H3K36me3, H3K4me1, H3K4me2, H3K4me3 and H3K9me3) and protein-DNA binding data (TAF1, P300, Pou5f1 and Nanog) using Chromatin Immunoprecipitation followed by short sequencing (ChIP-seq), cytosine methylation data using methylated DNA immunoprecipitation followed by sequencing (MeDIP-seq) and DNA digestion by methyl-sensitive restriction enzymes followed by sequencing (MRE-seq), transcriptome data with RNA short sequencing (RNA-seq) in human embryonic stem cells, mouse embryonic stem cells, pig induced pluripotent stem cells and mouse embryonic stem cells under activin-A-induced-differentiation. Examination of 8 histone modifications, 4 protein-DNA binding, cytosine methylation and transcriptome in human embryonic stem cells, mouse embryonic stem cells, pig induced pluripotent stem cells and mouse embryonic stem cells under activin-A-induced-differentiation.
Project description:This study aims to compare in vivo human trophoblast differentiation into EVTs to different in vitro trophoblast organoids using single-cell and single-nuclei RNA sequencing. The study includes two type of systems: human primary trophoblast organoids (PTO) and trophoblast stem cells (TSCs). Trophoblast stem cell (TSC) lines BTS5 and BTS11 derived by Okae and colleagues were grown as described previously (Okae et al. 2018) and together with EVT media. Primary trophoblast organoids (PTO) were grown and differentiated into EVT as previously described by Turco & Sheridan (Turco et al 2018; Sheridan et al 2020). This study shows that the main regulatory programs mediating EVT invasion in vivo are preserved in in vitro models of EVT differentiation from primary trophoblast organoids and trophoblast stem cells.
Project description:Human naive pluripotent stem cells have unrestricted lineage potential. Underpinning this property, naive cells are thought to lack chromatin-based lineage barriers. However, this assumption has not been tested. Here, we apply multi-omics to comprehensively define the chromatin-associated proteome, histone post-translational modifications and transcriptome of human naive and primed pluripotent stem cells. Integrating the chromatin-bound proteome and histone modification data sets reveals differences in the relative abundance and activities of distinct chromatin modules, identifying a strong enrichment of Polycomb Repressive Complex 2 (PRC2)-associated H3K27me3 in naive pluripotent stem cell chromatin. Single-cell approaches and human blastoid models reveal that PRC2 activity acts as a chromatin barrier restricting the differentiation of naive cells towards the trophoblast lineage, and inhibiting PRC2 promotes trophoblast fate induction and cavity formation. Our results establish that human naive pluripotent stem cells are not epigenetically unrestricted, but instead possess chromatin mechanisms that oppose the induction of alternative cell fates. Data originating from the LC-MS/MS analysis of the histone PTMs can be consulted via this project.
Project description:Human naive pluripotent stem cells have unrestricted lineage potential. Underpinning this property, naive cells are thought to lack chromatin-based lineage barriers. However, this assumption has not been tested. Here, we define the chromatin-associated proteome, histone post-translational modifications and transcriptome of human naive and primed pluripotent stem cells. Our integrated analysis reveals differences in the relative abundance and activities of distinct chromatin modules. We identify a strong enrichment of Polycomb Repressive Complex 2 (PRC2)-associated H3K27me3 in naive pluripotent stem cell chromatin, and H3K27me3 enrichment at promoters of lineage-determining genes, including trophoblast regulators. PRC2 activity acts as a chromatin barrier restricting the differentiation of naive cells towards the trophoblast lineage, while inhibition of PRC2 promotes trophoblast fate induction and cavity formation in human blastoids. Together, our results establish that human naive pluripotent stem cells are not epigenetically unrestricted, but instead possess chromatin mechanisms that oppose the induction of alternative cell fates.