Project description:Trophoblast stem (TS) cell renewal and differentiation are essential processes in placentation. Here, we have identified the mechanism/targets of chromatin organizer/transcription factor called special AT-rich binding protein 1 (SATB1) action on TS cell renewal by RNA-seq analysis in Rcho-1 TS cells expressing Satb1 shRNAs.
Project description:Esrrb is a transcription factor implicated in embryonic stem (ES) cell self-renewal, yet its knockout causes intrauterine lethality due to defects in trophoblast development. Here we show that in trophoblast stem (TS) cells, Esrrb is a downstream target of fibroblast growth factor (Fgf) signalling and is critical to drive TS cell self-renewal. In contrast to its occupancy of pluripotency-associated loci in ES cells, Esrrb sustains the stemness of TS cells by direct binding and regulation of TS cell-specific transcription factors including Elf5 and Eomes. To elucidate the mechanisms whereby Esrrb controls the expression of its targets, we characterized its TS cell-specific interactome by mass spectrometry. Unlike in ES cells, Esrrb interacts in TS cells with the histone demethylase Lsd1 and with the RNA Polymerase II-associated Integrator complex. Our findings provide new insights into both, the general and context-dependent wiring of transcription factor networks in stem cells by master transcription factors.
Project description:Hematopoietic stem cells (HSCs) are now recognized as a heterogeneous population in self-renewing and differentiation capabilities. However, fundamental mechanisms governing the heterogeneity remain uncertain. We here show that special AT-rich sequence-binding protein 1 (SATB1), a global chromatin organizer, is involved in the mechanisms. Analyzing hematological lineage-restricted SATB1 knock out mice proved that SATB1 is indispensable for both self-renewal and normal differentiation of adult HSCs. Using SATB1/Tomato knock-in mice, we subdivided HSCs according to SATB1 intensity. Culture experiments and RNA-sequencing revealed essential differences between SATB1- and SATB1+ HSCs regarding lineage potential.
Project description:Trophoblast stem cells (TS cells), derived from the trophectoderm (TE) of blastocysts, require transcription factors (TFs) and external signals (Fgf4, Activin/Nodal/Tgfb) for self-renewal. While many reports have focused on TF networks that regulate embryonic stem cell (ES cell) self-renewal and pluripotency, little is know about TF networks that regulate self-renewal in TS cells. To further understand transcriptional networks in TS cells we used chromatin immunopreciptiation and DNA microarray analysis (ChIP-chip) to investigate targets of TFs Ap-2g (Tcfap2c), Eomes, Ets2, and Gata3, and a chromatin remodeling factor, Brg1 (Smarca4). We then evaluated the transcriptional states of target genes using transcriptome analysis and genome-wide analysis of histone H3 acetylation (AcH3). Our results describe previously unknown transcriptional networks in TS cells, including TF occupancy of genes involved in ES cell self-renewal and pluripotency, co-occupancy of multiple TFs at target genes, and transcriptional regulatory circuitry within the 5 factors. Through genome-wide mapping and global expression analysis of 5 TF target genes, our data provide a comprehensive analysis of transcriptional networks that regulate TS cell self-renewal.
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:The Ets2 transcription factor is essential for the development of the mouse placenta and for generating signals for embryonic mesoderm and axis formation. Using a conditional targeted Ets2 allele, we show that Ets2 is essential for trophoblast stem (TS) cells self renewal. Inactivation of Ets2 results in slower growth, increased expression of a subset of differentiation associated genes and decreased expression of several genes implicated in TS self renewal. Among the direct TS targets of Ets2 is Cdx2, a key master regulator of TS cell state. In addition other Ets2 responsive genes include Pace4, Errb, Socs2 and Bmp4. Thus Ets2 contributes to the regulation of multiple genes important for maintaining the undifferentiated state of TS cells and as candidate signals for embryonic development. Keywords: cell type comparison
Project description:Trophoblast stem (TS) cells derived from the trophectoderm (TE) of mammalian embryos have the ability to self-renew indefinitely or differentiate into fetal lineages of the placenta. Epigenetic control of gene expression plays an instrumental role in dictating the fate of TS cell self-renewal and differentiation. However, the roles of histone demethylases and activating histone modifications such as methylation of histone 3 lysine 4 (H3K4me3/me2) in regulating TS cell expression programs, and in priming the epigenetic landscape for trophoblast differentiation, are largely unknown. Here, we demonstrate that the H3K4 demethylase, KDM5B, regulates the H3K4 methylome and expression landscapes of TS cells. Depletion of KDM5B resulted in downregulation of TS cell self-renewal genes and upregulation of trophoblast-lineage genes, which was accompanied by altered H3K4 methylation. Moreover, we found that KDM5B resets the H3K4 methylation landscape during differentiation in the absence of the external self-renewal signal, FGF4, by removing H3K4 methylation from promoters of self-renewal genes, and of genes whose expression is enriched in TS cells. Altogether, our data indicate an epigenetic role for KDM5B in regulating H3K4 methylation in TS cells and during trophoblast differentiation.
Project description:Trophoblast stem (TS) cells derived from the trophectoderm (TE) of mammalian embryos have the ability to self-renew indefinitely or differentiate into fetal lineages of the placenta. Epigenetic control of gene expression plays an instrumental role in dictating the fate of TS cell self-renewal and differentiation. However, the roles of histone demethylases and activating histone modifications such as methylation of histone 3 lysine 4 (H3K4me3/me2) in regulating TS cell expression programs, and in priming the epigenetic landscape for trophoblast differentiation, are largely unknown. Here, we demonstrate that the H3K4 demethylase, KDM5B, regulates the H3K4 methylome and expression landscapes of TS cells. Depletion of KDM5B resulted in downregulation of TS cell self-renewal genes and upregulation of trophoblast-lineage genes, which was accompanied by altered H3K4 methylation. Moreover, we found that KDM5B resets the H3K4 methylation landscape during differentiation in the absence of the external self-renewal signal, FGF4, by removing H3K4 methylation from promoters of self-renewal genes, and of genes whose expression is enriched in TS cells. Altogether, our data indicate an epigenetic role for KDM5B in regulating H3K4 methylation in TS cells and during trophoblast differentiation.