Expression data of human fetal liver hematopoietic stem and progenitors cells [Set 1]
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ABSTRACT: Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the CD90+ hematopoietic stem and progenitor population in fetal liver. RNA was extracted from enriched fetal liver hematopoietic stem and progenitor cells, and downstream progenitors, for comparison based on Affymetrix arrays.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the GPI-80+ hematopoietic stem and progenitor population in fetal liver. RNA was extracted from enriched fetal liver hematopoietic stem and progenitor cells, and downstream progenitors, for comparison based on Affymetrix arrays.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the CD90+ hematopoietic stem and progenitor population in fetal liver.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the GPI-80+ hematopoietic stem and progenitor population in fetal liver.
Project description:Life-long blood production requires long-term hematopoietic stem cells (LT-HSC) - marked by stemness states involving quiescence and self-renewal - to transition into activated short-term HSC (ST-HSC) with reduced stemness. As few transcriptional changes underlie this transition, we used single-cell and bulk ATAC-seq on human HSC and stem/progenitor subsets (HSPC) to uncover chromatin accessibility signatures, one including LT-HSC (LT/HSPC signature) and another excluding LT-HSC (Act/HSPC signature). These signatures inversely correlated during early hematopoietic commitment and differentiation. The Act/HSPC signature contains CTCF binding sites mediating 351 chromatin interactions, engaged in ST-HSC but not LT-HSC, enclosing multiple stemness pathway genes active in LT-HSC and repressed in ST-HSC. CTCF silencing derepressed stemness genes, restraining quiescent LT-HSC from transitioning to activated ST-HSC. Hence, 3D chromatin interactions centrally mediated by CTCF, endow a gatekeeper function that governs the earliest fate transitions HSC make by coordinating disparate stemness pathways linked to quiescence and self-renewal.
Project description:we investigate the role of YTHDC1 in normal hematopoiesis and adult hematopoietic stem/progenitor cell (HSPC) maintenance in vivo. Utilizing conditional Ythdc1 knockout mice ,we show that YTHDC1 is required for hematopoietic stem cell (HSC) maintenance as well as self-renewal of HSC. Transcriptome analysis identified many differentially expressed genes (DEGs) between WT and YTHDC1-KO LT-HSCs.
Project description:Gene expression analysis on purified human long-term hematopoietic stem cells (LT-HSC; CD34+CD38-CD90+) and short-term HSC (ST-HSC; CD34+CD38-CD90-) derived from healthy control patients and patients with myelodysplastic syndrome (MDS)
Project description:Increasing evidence links metabolic activity and cell growth to decline in hematopoietic stem cell (HSC) function during aging. The Lin28b/Hmga2 pathway controls tissue development and in the hematopoietic system the postnatal downregulation of this pathway causes a decrease in self renewal of adult HSCs compared to fetal HSCs. Igf2bp2 is an RNA binding protein and a mediator of the Lin28b/Hmga2 pathway, which regulates metabolism and growth signaling by influencing RNA stability and translation of its target genes. It is currently unknown whether Lin28/Hmga2/Igf2bp2 signaling impacts on aging-associated impairments in HSC function and hematopoiesis. Here, we analyzed homozygous Igf2bp2 germline knockout mice and wildtype control animals to address this question. The study shows that Igf2bp2 deletion rescues aging phenotypes of the hematopoietic system, such as the expansion of HSC numbers in bone marrow and the biased increase of myeloid cells in peripheral blood. This rescue of hematopoietic aging coincides with reduced mitochondrial metabolism and glycolysis in Igf2bp2-/- HSCs compared to Igf2bp2+/+ HSCs. Conversely, Igf2bp2 overexpression activates protein synthesis pathways in HSCs and leads to a rapid loss of self renewal by enhancing myeloid skewed differentiation in an mTOR/PI3K-dependent manner. Together, these results show that Igf2bp2 regulates energy metabolism and growth signaling in HSCs and that the activity of this pathways influences self renewal, differentiation, and aging of HSCs.
Project description:DNA methylation analysis on purified human long-term and short-term hematopoietic stem cells (LT-HSC, ST-HSC), common myeloid and megakaryocyte-erythrocyte progenitor cells (CMP, MEP) using HELP arrays. FACS-purified hematopoietic stem and progenitor cell (HSPC) subsets were analyzed for changes in DNA methylation using NimbleGen HELP microarrays. Analysis of DNA methylation of bone marrow-derived HSPC subsets of healthy human donors.
Project description:RNA expression analysis on purified human long-term and short-term hematopoietic stem cells (LT-HSC, ST-HSC), common myeloid and megakaryocyte-erythrocyte progenitor cells (CMP, MEP) using microarrays. FACS-purified hematopoietic stem and progenitor cell (HSPC) subsets were analyzed for changes in RNA expression using NimbleGen gene expression microarrays. Analysis of RNA expression of bone marrow-derived HSPC subsets of healthy human donors.
Project description:One of the long-standing goals in the field has been to establish a culture system that would allow maintenance of HSC properties ex vivo. In the absence of such system, the ability to model human hematopoiesis in vitro has been limited, and there has been little progress in the expansion of human HSCs for clinical application. To that end, we defined a mesenchyml stem cell co-culture system for expansion of clonally multipotent human HSPCs that are protected from apoptosis and immediate differentiation, and retain the HSPC phenotype. By performing a genome-wide gene expression analysis of purified HSPCs isolated at different stages of co-culture, we asked at the molecular level, to what degree hematopetic stem cell properties can be preserved during culture. This temporal gene expression data from in vivo derived- and ex vivo expanded human HSPCs will serve as a resource to identify novel regulatory pathways that control HSC properties, and to develop clinically applicable protocols for HSC expansion. Human CD34+ fetal liver cells were co-cultured on a subclone of OP9 stomal cells (OP9M2 sublemented with supportive cytokines (see below)). To distinguish between molecular changes acquired over prolonged culture versus immediately after exposure to culture, gene expression in isolated CD45+CD34+CD38-CD90+ HSPCs was assessed after 12 hours, 2 weeks and 5 weeks in culture. Cultured CD45+CD34+CD38-CD90+HSPCs were compared to freshly isolated CD45+CD34+CD38-CD90+HSPCs and their more differentiated CD45+CD34+CD38+CD90- downstream progenitor cells.