Genome-wide Transcription Factor binding maps reveal cell-specific changes in the regulatory architecture of human HSPC [ChIPmentation]
Ontology highlight
ABSTRACT: Hematopoietic stem and progenitor cells (HSPCs) rely on a complex interplay of transcription factors (TFs) to regulate their differentiation into mature blood cells. A heptad of TFs - FLI1, ERG, GATA2, RUNX1, TAL1, LYL1, LMO2 - has been shown to bind to regulatory elements in bulk CD34+ HSPCs. However, whether specific combinations of these TFs have distinct roles in regulating hematopoietic differentiation remained unknown. In this study, we mapped the genome-wide binding profiles of these TFs and other chromatin-associated markers in distinct HSPC subsets (HSC, CMP, GMP, MEP). We found that the heptad occupancy and enhancer-promoter interactions varied significantly across cell types and were associated with cell-type specific gene expression. Moreover, we observed distinct regulatory elements that were enriched with specific combinations of TFs, such as stem-cell specific elements with ERG, and myeloid and megakaryocyte-erythroid specific elements with combinations of FLI1, RUNX1, GATA2, TAL1, LYL1, and LMO2. These findings suggest that specific combinations of TFs play critical roles in the regulation of hematopoietic differentiation, and provide a valuable resource for the development of targeted therapies to manipulate specific HSPC subsets.
Project description:Hematopoietic stem and progenitor cells (HSPCs) rely on a complex interplay of transcription factors (TFs) to regulate their differentiation into mature blood cells. A heptad of TFs - FLI1, ERG, GATA2, RUNX1, TAL1, LYL1, LMO2 - has been shown to bind to regulatory elements in bulk CD34+ HSPCs. However, whether specific combinations of these TFs have distinct roles in regulating hematopoietic differentiation remained unknown. In this study, we mapped the genome-wide binding profiles of these TFs and other chromatin-associated markers in distinct HSPC subsets (HSC, CMP, GMP, MEP). We found that the heptad occupancy and enhancer-promoter interactions varied significantly across cell types and were associated with cell-type specific gene expression. Moreover, we observed distinct regulatory elements that were enriched with specific combinations of TFs, such as stem-cell specific elements with ERG, and myeloid and megakaryocyte-erythroid specific elements with combinations of FLI1, RUNX1, GATA2, TAL1, LYL1, and LMO2. These findings suggest that specific combinations of TFs play critical roles in the regulation of hematopoietic differentiation, and provide a valuable resource for the development of targeted therapies to manipulate specific HSPC subsets.
Project description:Hematopoietic stem and progenitor cells (HSPCs) rely on a complex interplay of transcription factors (TFs) to regulate their differentiation into mature blood cells. A heptad of TFs - FLI1, ERG, GATA2, RUNX1, TAL1, LYL1, LMO2 - has been shown to bind to regulatory elements in bulk CD34+ HSPCs. However, whether specific combinations of these TFs have distinct roles in regulating hematopoietic differentiation remained unknown. In this study, we mapped the genome-wide binding profiles of these TFs and other chromatin-associated markers in distinct HSPC subsets (HSC, CMP, GMP, MEP). We found that the heptad occupancy and enhancer-promoter interactions varied significantly across cell types and were associated with cell-type specific gene expression. Moreover, we observed distinct regulatory elements that were enriched with specific combinations of TFs, such as stem-cell specific elements with ERG, and myeloid and megakaryocyte-erythroid specific elements with combinations of FLI1, RUNX1, GATA2, TAL1, LYL1, and LMO2. These findings suggest that specific combinations of TFs play critical roles in the regulation of hematopoietic differentiation, and provide a valuable resource for the development of targeted therapies to manipulate specific HSPC subsets.
Project description:Hematopoietic stem and progenitor cells (HSPCs) rely on a complex interplay of transcription factors (TFs) to regulate their differentiation into mature blood cells. A heptad of TFs - FLI1, ERG, GATA2, RUNX1, TAL1, LYL1, LMO2 - has been shown to bind to regulatory elements in bulk CD34+ HSPCs. However, whether specific combinations of these TFs have distinct roles in regulating hematopoietic differentiation remained unknown. In this study, we mapped the genome-wide binding profiles of these TFs and other chromatin-associated markers in distinct HSPC subsets (HSC, CMP, GMP, MEP). We found that the heptad occupancy and enhancer-promoter interactions varied significantly across cell types and were associated with cell-type specific gene expression. Moreover, we observed distinct regulatory elements that were enriched with specific combinations of TFs, such as stem-cell specific elements with ERG, and myeloid and megakaryocyte-erythroid specific elements with combinations of FLI1, RUNX1, GATA2, TAL1, LYL1, and LMO2. These findings suggest that specific combinations of TFs play critical roles in the regulation of hematopoietic differentiation, and provide a valuable resource for the development of targeted therapies to manipulate specific HSPC subsets.
Project description:The ATAC-seq is one of three readouts of an experiment carried out to assess the ability of different combinations of hematopoietic transcription factors to elicit the transdifferentiation of a mESC-derived non-hematopoietic cell type (vascular smooth muscle cells) into hematopoietic precursors upon dox-induced overexpression. The assessed trascription factors are Tal1, Lyl1 and Lmo2 (i3TFs), Runx1, Cbfb, Gata2, Fli1, Erg (i5TFs) and Runx1, Cbfb, Gata2, Tal1, Fli1, Lyl1, Erg, Lmo2 (i8TFs). The constructs for TF expression were stably integrated into mESCs and their expression induced by treatment with dox. i: inducible.
Project description:The RNA-seq is one of three readouts of an experiment carried out to assess the ability of different combinations of hematopoietic transcription factors to elicit the transdifferentiation of a mESC-derived non-hematopoietic cell type (vascular smooth muscle cells) into hematopoietic precursors upon dox-induced overexpression. The assessed trascription factors are Tal1, Lyl1 and Lmo2 (i3TFs), Runx1, Cbfb, Gata2, Fli1, Erg (i5TFs) and Runx1, Cbfb, Gata2, Tal1, Fli1, Lyl1, Erg, Lmo2 (i8TFs). The constructs for TF expression were stably integrated into mESCs and their expression induced by treatment with dox. i: inducible.
Project description:Combinatorial transcription factor (TF) interactions regulate hematopoietic stem cell formation, maintenance and differentiation, and are increasingly recognised as drivers of stem cell signatures in cancer. However, genome-wide combinatorial binding patterns for key regulators do not exist in primary human hematopoietic stem/progenitor cells (HSPCs) and have constrained analysis of the global architecture of the molecular circuits controlling these cells. Here we provide new high-resolution genome-wide binding maps of seven key TFs (FLI1, ERG, GATA2, RUNX1, SCL, LYL1 and LMO2) in human CD34+ HSPCs together with quantitative RNA and microRNA expression profiles. We catalogue binding of TFs at coding genes and microRNA promoters and report that combinatorial binding of all seven TFs is favoured and is associated with differential expression of genes and microRNA in HSPCs. We also uncover a hitherto unrecognized association between FLI1 and RUNX1 pairing in HSPCs, establish a correlation between the density of histone modifications, which mark active enhancers and the number of overlapping TFs at a peak and identify complex relationships between specific miRNAs and coding genes regulated by the heptad. Taken together, this study demonstrates that a heptad of TFs forms a dense auto-regulatory core in human HSPCs with binding of all seven TFs at tissue specific regulatory elements of heptad genes and collectively regulates miRNAs that in turn target components of the heptad and genes regulated by the heptad. Examination of cominatorial binding by 7 transcription factors, 1 IgG control along with mRNA and small RNA sequencing in human CD34+ cells
Project description:Blood production is maintained through adult life by haematopoietic stem cells which undergo a process of differentiation and increasing lineage restriction to produce all the terminal blood types. The cell type transitions within this process are tightly controlled, and loss of control can lead to inappropriate proliferation and leukemic transformation. We and others have previously described seven transcriptional regulators (heptad; LYL1, TAL1, LMO2, FLI1, ERG, GATA2, RUNX1) which bind key haematopoietic genes in normal human CD34+ haematopoietic stem and progenitor cells (HSPCs). Heptad factors form a densely interconnected circuit by binding combinatorically at their own, and each other’s, regulatory elements. However, the precise role of the heptad throughout normal and leukemic haematopoiesis, including whether all seven factors act together in single cells, and whether heptad perturbation can influence cell fate decisions remain unclear. In this study we integrate bulk and single cell data in normal human HSPCs and leukemic cells and find that chromatin conformation at key heptad regulatory elements is predictive of cell identity in normal and leukemic progenitors. The interconnected heptad circuit identified in normal HSPCs persists in AML, but single cell transcriptomics suggest that specific heptad sub-circuits exist in individual cells, and we show that GATA2, TAL1 and ERG play key roles in regulating the stem to erythroid transition in both normal and leukemic contexts.
Project description:Blood production is maintained through adult life by haematopoietic stem cells which undergo a process of differentiation and increasing lineage restriction to produce all the terminal blood types. The cell type transitions within this process are tightly controlled, and loss of control can lead to inappropriate proliferation and leukemic transformation. We and others have previously described seven transcriptional regulators (heptad; LYL1, TAL1, LMO2, FLI1, ERG, GATA2, RUNX1) which bind key haematopoietic genes in normal human CD34+ haematopoietic stem and progenitor cells (HSPCs). Heptad factors form a densely interconnected circuit by binding combinatorically at their own, and each other’s, regulatory elements. However, the precise role of the heptad throughout normal and leukemic haematopoiesis, including whether all seven factors act together in single cells, and whether heptad perturbation can influence cell fate decisions remain unclear. In this study we integrate bulk and single cell data in normal human HSPCs and leukemic cells and find that chromatin conformation at key heptad regulatory elements is predictive of cell identity in normal and leukemic progenitors. The interconnected heptad circuit identified in normal HSPCs persists in AML, but single cell transcriptomics suggest that specific heptad sub-circuits exist in individual cells, and we show that GATA2, TAL1 and ERG play key roles in regulating the stem to erythroid transition in both normal and leukemic contexts.
Project description:Blood production is maintained through adult life by haematopoietic stem cells which undergo a process of differentiation and increasing lineage restriction to produce all the terminal blood types. The cell type transitions within this process are tightly controlled, and loss of control can lead to inappropriate proliferation and leukemic transformation. We and others have previously described seven transcriptional regulators (heptad; LYL1, TAL1, LMO2, FLI1, ERG, GATA2, RUNX1) which bind key haematopoietic genes in normal human CD34+ haematopoietic stem and progenitor cells (HSPCs). Heptad factors form a densely interconnected circuit by binding combinatorically at their own, and each other’s, regulatory elements. However, the precise role of the heptad throughout normal and leukemic haematopoiesis, including whether all seven factors act together in single cells, and whether heptad perturbation can influence cell fate decisions remain unclear. In this study we integrate bulk and single cell data in normal human HSPCs and leukemic cells and find that chromatin conformation at key heptad regulatory elements is predictive of cell identity in normal and leukemic progenitors. The interconnected heptad circuit identified in normal HSPCs persists in AML, but single cell transcriptomics suggest that specific heptad sub-circuits exist in individual cells, and we show that GATA2, TAL1 and ERG play key roles in regulating the stem to erythroid transition in both normal and leukemic contexts.
Project description:The aim of the experiment was to study the transcriptome changes occuring after overexpression of Erg, Fli1, Tal1, Lyl1, Lmo2, Runx1, Cbfb and Gata2 in endothelial (Endo) and enriched vascular smooth muscles (eVSM) populations.