ABSTRACT: Transcription profiling by array of primary megakaryocytes (MEG) and erythroblasts (ERY) developed from murine fetal liver hematopoietic stem cells
Project description:We examined the transcriptomes of murine "expandable hemangioblasts" (eHBs) and their blood and endothelial progeny, comparing them to the transcriptomes of murine embryonic stem (ES) cells, primary murine endothelial cells isolated from E11.5 yolk sacs or embryos, and E14.5 fetal liver hematopoietic stem cells.
Project description:We examined the transcriptomes of murine "expandable hemangioblasts" (eHBs) and their blood and endothelial progeny, comparing them to the transcriptomes of murine embryonic stem (ES) cells, primary murine endothelial cells isolated from E11.5 yolk sacs or embryos, and E14.5 fetal liver hematopoietic stem cells. Total RNAs were purified from lysates of cultured or primary cells, reverse transcribed, and sequenced on an Illumina HiSeq 2500.
Project description:Combinatorial actions of relatively few transcription factors control hematopoietic differentiation. To investigate this process in erythro-megakaryopoiesis, we correlated the genome-wide chromatin occupancy signatures of four master hematopoietic transcription factors (GATA1, GATA2, SCL/TAL1 and FLI1) and three diagnostic histone modification marks with the gene expression changes that occur during development of primary megakaryocytes (MEG) and erythroblasts (ERY) from murine fetal liver hematopoietic stem/progenitor cells. We identified a robust, genome-wide mechanism of MEG-specific lineage priming by a previously described stem/progenitor cell-expressed transcription factor heptad (GATA2, LYL1, SCL/TAL1, FLI1, ERG, RUNX1, LMO2) binding to MEG-specific cis-regulatory modules in multipotential hematopoietic progenitors. This is followed by genome-wide GATA factor switching that mediates further induction of MEG-specific genes following lineage commitment. Interaction between GATA and ETS factors appears to be a key determinant of these processes. In contrast, ERY-specific lineage priming occurs is biased toward GATA2-independent mechanisms. In addition to its role in MEG lineage priming, GATA2 plays an extensive role in late megakaryopoiesis as a transcriptional repressor at loci defined by a specific DNA signature. Our findings reveal important new insights into how ERY and MEG lineages arise from a common bipotential precursor via overlapping and divergent functions of shared hematopoietic transcription factors. Gene expression changes during the development of primary megakaryocytes (MEG) and erythroblasts (ERY) from murine fetal liver hematopoietic stem/progenitor cells
Project description:Human pluripotent stem cells were differentiated into hematopoietic progenitors, which were then re-specified using defined transcription factors to resemble hematopoietic stem cells (HSC) We used microarrays to establish the similarity between converted cells and purified human HSCs. The samples analyzed were: starting embryoid body progenitors, transcription factor-converted cells, and primary HSCs and progenitors from fetal liver and cord blood. All samples were flow sorted for CD34+ and CD38- to compare across a similar population of primitive cells.
Project description:This SuperSeries is composed of the following subset Series: GSE36984: Expression Profiling of Primary Human Fetal and Adult Hematopoietic Stem/Progenitor Cells (HSPCs) and Differentiating Proerythroblasts (ProEs) GSE36985: Comparative profiling of chromatin state maps and transcription factor occupancy during human fetal and adult erythropoiesis GSE36988: Expression Profiling of Primary Human Proerythroblasts (ProEs) After IRF2, IRF6, and MYB shRNA Knockdown Refer to individual Series
Project description:TurboID (biotin proximity ligase) was fused to AML-associated oncofusions (PML::RARA, RUNX1::RUNX1T1, CBFB::MYH11), wildtype NPM1, or mutated NPMc and expressed in murine hematopoietic stem/progenitor cells using MSCV-based retroviruses to identify key interacting proteins in primary hematopoietic cells.
Project description:We assesed the transcriptional profiles of sorted SLAM-LSK hematopoietic stem cells (HSCs) during expansion in the murine fetal liver from WT and Jag1-null mutants at embryonic day 14.5 post-conception. The goals of the study are to compare the expression profiles of rapidly proliferating fetal HSCs when the Notch ligand Jag1 is specifically deleted in the hematopoietic compartment. We find that hematopoietic deletion of Jag1 negatively impacts the expression of critical hematopoietic cell fate and identity genes such as GATA2, Mllt3 and Hoxa7. Our study establishes a unique role for Notch signaling activation in the fetal liver by the hematopoietic Jag1 ligand.
Project description:Genome-wide profiling of RNA expression in two sub-populations of hematopoietic stem cells from mouse Fetal Liver (FL) and adult Bone Marrow (BM)
Project description:Human bone marrow stromal cells (BMSCs) are key elements of the hematopoietic environment and they play a central role in bone and bone marrow physiology. However, how key BMSC functions are regulated is largely unknown. We analyzed the role of the immediate early response transcription factor EGR1 as key BMSC regulator and found that EGR1 was highly expressed in prospectively-isolated primary BMSCs, downregulated upon culture, and lower in non-CFU-F-containing CD45neg BM cells. Furthermore, EGR1 expression was lower in proliferative regenerating adult and fetal primary cells compared to adult steady-state BMSCs. Accordingly, EGR1 overexpression markedly decreased BMSC proliferation but considerably improved hematopoietic stroma support function as indicated by an increased production of transplantable CD34+CD90+ hematopoietic stem cells in expansion co-cultures. The improvement of BMSC stroma support function was mediated by increased expression of hematopoietic supporting genes, such as VCAM1 and CCL28. On the other hand, EGR1 knockdown increased ROS-mediated BMSC proliferation, and clearly reduced BMSC hematopoietic stroma support potential. These findings thus show that EGR1 is a key BMSC transcription factor with a dual role in regulating proliferation and hematopoietic stroma support function that is controlling a genetic program to coordinate the specific functions of BMSC in their different biological contexts.
Project description:Combinatorial actions of relatively few transcription factors control hematopoietic differentiation. To investigate this process in erythro-megakaryopoiesis, we correlated the genome-wide chromatin occupancy signatures of four master hematopoietic transcription factors (GATA1, GATA2, TAL1, and FLI1) and three diagnostic histone modification marks with the gene expression changes that occur during development of primary cultured megakaryocytes (MEG) and primary erythroblasts (ERY) from murine fetal liver hematopoietic stem/progenitor cells. We identified a robust, genome-wide mechanism of MEG-specific lineage priming by a previously described stem/progenitor cell-expressed transcription factor heptad (GATA2, LYL1, TAL1, FLI1, ERG, RUNX1, LMO2) binding to MEG-associated cis-regulatory modules (CRMs) in multipotential progenitors. This is followed by genome-wide GATA factor switching that mediates further induction of MEG-specific genes following lineage commitment. Interaction between GATA and ETS factors appears to be a key determinant of these processes. In contrast, ERY-specific lineage priming is biased toward GATA2-independent mechanisms. In addition to its role in MEG lineage priming, GATA2 plays an extensive role in late megakaryopoiesis as a transcriptional repressor at loci defined by a specific DNA signature. Our findings reveal important new insights into how ERY and MEG lineages arise from a common bipotential progenitor via overlapping and divergent functions of shared hematopoietic transcription factors. Genome-wide chromatin occupancy using ChIP-seq on 4 transcription factors (GATA1, GATA2, TAL1, and FLII) and three histone marks (H3K4me1, H3K4me3, and H3K27me3) in lineage-commited primary erythoblasts (ERY) and primary cultured megakaryocytes (MEG).