Whole gene expression data from Gfi-1-/- and Gfi-1-/-;Id2+/- mouse bone marrow cells
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ABSTRACT: To understand molecular mechanisms by which reducing Id2 rescues impaired erythropoiesis and hematopoietic progenitor cell development in Gfi-1-/- mice, we compared gene expression in Gfi-1-/-;Id2+/- and Gfi-1-/- BMC using Affymetrix microarray.
Project description:To understand molecular mechanisms by which reducing Id2 rescues impaired erythropoiesis and hematopoietic progenitor cell development in Gfi-1-/- mice, we compared gene expression in Gfi-1-/-;Id2+/- and Gfi-1-/- BMC using Affymetrix microarray. Total RNA samples from four individual Gfi-1-/- or Gfi-1-/-;Id2+/- mice were arrayed using the GeneChip Mouse Gene 1.0 ST Array (Affymetrix, Santa Clara, CA).
Project description:Defining mechanism(s) that maintain tissue stem quiescence is important for improving tissue regeneration, cell therapies, aging, and cancer. We report here that genetic ablation of Id2 in adult hematopoietic stem cells (HSCs) promotes increased HSC activation and differentiation, which results in HSC exhaustion and bone marrow failure over time. Id2Δ/Δ HSCs show increased HSC cycling, reactive oxygen species (ROS) production, mitochondrial activation, and DNA damage supporting the conclusion that Id2Δ/Δ HSCs are less quiescent. Mechanistically, HIF-1α expression is decreased in Id2Δ/Δ HSCs, and stabilization of HIF-1α in Id2Δ/Δ HSCs restores HSC quiescence and rescues HSC exhaustion. ID2 promotes HIF-1α expression by binding to the Von Hippel-Lindau (VHL) protein and interfering with proteasomal degradation of HIF-1α. HIF-1α promotes Id2 expression and enforces a positive feedback loop between ID2 and HIF-1α to maintain HSC quiescence. Thus, sustained ID2 expression could protect HSCs during stress, and improve HSC expansion for gene editing and cell therapies.
Project description:Defining mechanism(s) that maintain tissue stem quiescence is important for improving tissue regeneration, cell therapies, aging, and cancer. We report here that genetic ablation of Id2 in adult hematopoietic stem cells (HSCs) promotes increased HSC activation and differentiation, which results in HSC exhaustion and bone marrow failure over time. Id2Δ/Δ HSCs show increased cycling, reactive oxygen species (ROS) production, mitochondrial activation, ATP production, and DNA damage compared to Id2+/+ HSCs, supporting the conclusion that Id2Δ/Δ HSCs are less quiescent. Mechanistically, HIF-1α expression is decreased in Id2Δ/Δ HSCs, and stabilization of HIF-1α in Id2Δ/Δ HSCs restores HSC quiescence and rescues HSC exhaustion. ID2 promotes HIF-1α expression by binding to the Von Hippel-Lindau (VHL) protein and interfering with proteasomal degradation of HIF-1α. HIF-1α promotes Id2 expression and enforces a positive feedback loop between ID2 and HIF-1α to maintain HSC quiescence. Thus, sustained ID2 expression could protect HSCs during stress, and improve HSC expansion for gene editing and cell therapies.
Project description:Hematopoietic stem cells give rise to all blood lineages, can fully re-populate the bone marrow, and easily outlive the host organism. To better understand how stem cells remain fit during aging, we analyzed the proteome of hematopoietic stem and progenitor cells.
Project description:During an immune response, CD8 T cells fall along a gradient of memory potential, but the regulators of these fate decsisions are not well understood. We utlized Id3-GFP and Id2-YFP reporter mice to elucidate the role of Id3 and Id2 during early CD8 T cell differentiation by gene expression. Id3-GFP hi Id2-YFP int or Id3-GFP lo Id2-YFP hi OT-I cells were sorted into trizol at day 6 of VSV-OVA infection and analyzed by microarray
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:The ID family of proteins (ID1-4), which bind to basic helix-loop-helix (bHLH) transcription factors and prevent bHLH-directed transcription, are critical regulators of the differentiation and chemoresistance of cancer cells derived from multiple cellular lineages. ID2 was previously shown to impair the in vitro differentiation of human mesenchymal stem cells. However, the functional role, if any, of ID2 in regulating differentiation, developmental pathways, and the oncogenic phenotype of Ewing sarcoma tumors is unknown. We used CRISPR/Cas9 to knockout ID2 in Ewing sarcoma cell lines and identified that the loss of ID2 significantly decreases cell growth in vitro and in vivo in a xenograft experiment. Using RNA-seq and gene set enrichment analysis with ID2-knockout and ID2-Knockout-Rescue cell lines we identified that ID2 regulates genes related to differentiation and development in Ewing sarcoma cell lines.
Project description:Growth Factor Independence-1B (Gfi-1B) is a transcriptional repressor essential for erythropoiesis and megakaryopoiesis. Targeted gene disruption of Gfi-1B in mice leads to embryonic lethality due to failure to produce definitive erythrocytes, hindering the study of Gfi-1B function in adult hematopoiesis. We here show that, in humans, Gfi-1B controls the development of erythrocytes and megakaryocytes by regulating the proliferation and differentiation of bipotent erythro-megakaryocytic progenitors (MEP). We further identify in this cell population the type III transforming growth factor-? receptor gene, TGFBR3, as a direct target of Gfi-1B. Knock down of Gfi-1B results in altered TGF? signaling as shown by the increase in Smad2 phosphorylation and its inability to associate to the Transcription Intermediary Factor 1? (TIF1?). Because Smad2/TIF1? complex is known to specifically regulate erythroid differentiation, we propose that, by repressing the transforming growth factor-? receptor III (T?R?II) expression, Gfi-1B favors the Smad2/TIF1? interaction downstream of TGF? signaling, allowing immature progenitors to differentiate toward the erythroid lineage.
Project description:Aim: The mammalian gut is the largest endocrine organ. Dozens of hormones secreted by enteroendocrine cells regulate a variety of physiological functions of the gut but also of the pancreas and brain. Here, we examined the role of the helix-loop-helix transcription factor ID2 during the differentiation of intestinal stem cells along the enteroendocrine lineage. Methods: To assess the functions of ID2 in the adult mouse small intestine, we used single-cell RNA sequencing, genetically modified mice, and organoid assays. Results: We found that in the adult intestinal epithelium Id2 is predominantly expressed in enterochromaffin and peptidergic enteroendocrine cells. Consistently, the loss of Id2 leads to the reduction of Chromogranin A-positive enteroendocrine cells. In contrast, the numbers of tuft cells are increased in Id2 mutant small intestine. Moreover, ablation of Id2 elevates the numbers of Serotonin+ enterochromaffin cells and Ghrelin+ X-cells in the posterior part of the small intestine. Finally, Id2 acts downstream of BMP signalling during the differentiation of Glucagon Like Peptide-1+ L-cells and Cholecystokinin+ I-cells towards Neurotensin+PYY+ N-cells. Conclusion: Id2 plays an important role in cell fate decisions in the adult small intestine. Firstly, ID2 suppresses the differentiation of secretory intestinal epithelial progenitors towards tuft cell lineage and thus controls host immune response on commensal and parasitic microbiota. Next, ID2 is essential for establishing a differentiation gradient for enterochromaffin and X-cells along the anterior-posterior axis of the gut. Finally, ID2 is necessary for the differentiation of N-cells thus ensuring a differentiation gradient along the crypt-villi axis.