Project description:Adult and fetal hematopoietic stem cells (HSCs) display a glycolytic phenotype, which is required for maintenance of stemness; however, whether mitochondrial respiration is required to maintain HSC function is not known. Here we report that loss of the mitochondrial complex III subunit Rieske iron sulfur protein (RISP) in fetal mouse HSCs allows them to proliferate but impairs their differentiation, resulting in anemia and prenatal death. RISP null fetal HSCs displayed impaired respiration resulting in a decreased NAD+/NADH ratio. RISP null fetal HSCs and progenitors exhibited an increase in both DNA and histone methylation concomitant with increases in 2-hydroxyglutarate (2-HG), a metabolite known to inhibit DNA and histone demethylases. RISP inactivation in adult HSCs also impaired respiration resulting in loss of quiescence resulting in severe pancytopenia and lethality. Thus, respiration is dispensable for adult or fetal HSC proliferation, but essential for fetal HSC differentiation and maintenance of adult HSC quiescence.
Project description:Infant and adult MLL-rearranged (MLLr) leukemia represents a disease with few treatment options and a dismal prognosis. Here, we present an in-depth proteomic characterization of in utero-initiated and adult-onset MLLr leukemia in a mouse model of MLL-ENL-mediated leukemogenesis. We characterize early proteomic events of MLL-ENL-mediated transformation in fetal and adult progenitors.
Project description:We describe the proteomic composition of the extracellular environment of fetal and adult hematopoietic progenitors by data-independent acquisition mass spectrometry analysis.
Project description:The transcription factor SOX17 is expressed by fetal, but not adult hematoipoietic stem cells (HSCs), and is required for the maintenance of fetal and neonatal, but not adult, HSCs. In the current study we show that ectopic expression of Sox17 in adult HSCs and transiently reconstituting multipotent progenitors was sufficient to confer increased self-renewal potential and the expression of fetal HSC genes including fetal HSC surface markers. To assess the mechanisms by which ectopic Sox17 expression in adult hematopoietic progenitors increased self-renewal potential and conferred fetal HSC properties, we compared the gene expression profiles of E16.5 fetal liver HSCs, young adult bone marrow HSCs, young adult bone marrow CD48+LSK cells, and Sox17-expressing CD48+LSK cells isolated from mice that had been transplanted with MSCV-Sox17-infected bone marrow cells 12 weeks earlier.
Project description:The transcription factor SOX17 is expressed by fetal, but not adult hematoipoietic stem cells (HSCs), and is required for the maintenance of fetal and neonatal, but not adult, HSCs. In the current study we show that ectopic expression of Sox17 in adult HSCs and transiently reconstituting multipotent progenitors was sufficient to confer increased self-renewal potential and the expression of fetal HSC genes including fetal HSC surface markers. To assess the mechanisms by which ectopic Sox17 expression in adult hematopoietic progenitors increased self-renewal potential and conferred fetal HSC properties, we compared the gene expression profiles of E16.5 fetal liver HSCs, young adult bone marrow HSCs, young adult bone marrow CD48+LSK cells, and Sox17-expressing CD48+LSK cells isolated from mice that had been transplanted with MSCV-Sox17-infected bone marrow cells 12 weeks earlier. Total RNA (~5ng) was isolated from 3 independent, freshly isolated aliquots of 10,000 E16.5 fetal liver HSCs, 10,000 fetal liver CD48+LSK cells, 10,000 adult bone marrow HSCs, 10,000 adult bone marrow CD48+LSK cells, 10,000 Sox17-expressing CD48+LSK cells isolated from primary recipients 12 weeks after transplantation of MSCV-Sox17-infected bone marrow cells. Purified RNA was reverse transcribed and amplified using the WT-Ovation™ Pico RNA Amplification system (NuGEN Technologies) following the manufacturer’s instructions. Sense strand cDNA was generated using WT-Ovation™ Exon Module (NuGEN), then fragmented and labeled using the FL-Ovation™ cDNA Biotin Module V2 (NuGEN). 2.5µg of labeled cDNA were hybridized to Affymetrix Mouse Gene ST 1.0 microarrays.
Project description:We describe the proteomic composition of the secretome of fetal and adult hematopoietic progenitors during MLL-rearranged (MLLr) leukemia initiation as well as the pre-leukemic cells’ secretion response to the treatment with Fibulin (Fbln1) and/or Fibronectin (Fn1) using data-independent acquisition mass spectrometry analysis.
Project description:Mouse B cell precursors from fetal liver and adult bone marrow generate distinctive B cell progeny when transplanted into immunodeficient recipients, supporting a two-pathway model for B lymphopoiesis, fetal “B-1” and adult “B-2”. Recently Lin28b was shown to be important for the switch between fetal and adult pathways; however, neither the mechanism of Lin28b action nor the importance of BCR signaling in this process was addressed. Here we report important advances in our understanding of the regulation of B 1/B-2 development. First, modulation of Let-7 in fetal Pro-B cells is sufficient to alter fetal B-1 development to produce B cells resembling the progeny of adult B-2 development. Second, intact BCR signaling is required for generation of B1a B cells from Lin28b-transduced bone marrow progenitors, supporting a requirement for ligand-dependent selection, as is the case for normal B1a B cells. Third, the VH repertore of Lin28b-induced bone marrow B1a B cells differs from that of normal B1a. Finally we identify the Arid3a transcription factor as a key target of Let-7, whose ectopic expression is sufficient to induce B-1 development in adult Pro-B cells and whose knockdown blocks B-1 development in fetal Pro-B cells. 4 individual sorts of Fr.A and Fr.B/C fractions in bone marrow and fetal liver of BALB/c mice
Project description:To investigate whether liver-resident ILC1s could develop from local hematopoietic progenitors, we analyzed the phenotypic properties of liver CD45+Lin- progenitors. We found that the adult mouse liver contained Lin-Sca-1+Mac-1+ (LSM) hematopoietic progenitors derived from the fetal liver. This population included Lin-CD122+CD49a+ progenitors that could generate liver ILC1s but not conventional NK (cNK) cells. By performing single-cell RNA seq, we show the heterogeneous composition of these hematopoietic progenitors.
Project description:Mouse B cell precursors from fetal liver and adult bone marrow generate distinctive B cell progeny when transplanted into immunodeficient recipients, supporting a two-pathway model for B lymphopoiesis, fetal M-bM-^@M-^\B-1M-bM-^@M-^] and adult M-bM-^@M-^\B-2M-bM-^@M-^]. Recently Lin28b was shown to be important for the switch between fetal and adult pathways; however, neither the mechanism of Lin28b action nor the importance of BCR signaling in this process was addressed. Here we report important advances in our understanding of the regulation of B 1/B-2 development. First, modulation of Let-7 in fetal Pro-B cells is sufficient to alter fetal B-1 development to produce B cells resembling the progeny of adult B-2 development. Second, intact BCR signaling is required for generation of B1a B cells from Lin28b-transduced bone marrow progenitors, supporting a requirement for ligand-dependent selection, as is the case for normal B1a B cells. Third, the VH repertore of Lin28b-induced bone marrow B1a B cells differs from that of normal B1a. Finally we identify the Arid3a transcription factor as a key target of Let-7, whose ectopic expression is sufficient to induce B-1 development in adult Pro-B cells and whose knockdown blocks B-1 development in fetal Pro-B cells. 3 individual sorts of Fr.B/C fractions from bone marrow and fetal liver of BALB/c mice