Project description:To facilitate comparative genomic analyses of human fetal and adult cells undergoing erythropoiesis, we employed a serum-free two-phase liquid culture system to expand and differentiate primary human CD34+ hematopoietic stem/progenitor cells (HSPCs) ex vivo. In this experimental context, highly enriched populations of stage-matched, differentiating, primary proerythroblasts (ProEs) were generated. We selected four time points (day 0, CD34+ HSPCs; day 3, 5, and 7, differentiating ProEs) that represented similar stages differentiation for gene expression profiling using microarrays. Primary maturing fetal or adult erythroblasts were generated ex vivo from CD34+ hematopoietic stem/progenitor cells (HSPCs) using a serum-free two-phase liquid culture system. Total RNA from primary fetal and adult HSPCs (day 0) and differentiating proerythroblasts (ProEs; day 3, 5, and 7) were extracted and used to hybridize to Affymetrix expression arrays using the HG-U133 Plus 2.0 platform.
Project description:Fetal and adult hematopoietic stem and progenitor cells (HSPCs) are characterized by distinct redox homeostasis that may influence their differential cellular behaviour in normal and malignant haematopoiesis. In this work, we have applied a quantitative mass spectrometry-based redox proteomic approach to comprehensively describe reversible cysteine modifications in primary mouse fetal and adult HSPCs. We defined the redox state of 4455 cysteines in fetal and adult HSPCs and demonstrated a higher susceptibility to oxidation of protein thiols in fetal HSPCs. Our data identified ontogenically active redox switches in proteins with a pronounced role in metabolism and protein homeostasis. Additional redox proteomic analysis identified redox switches acting in mitochondrial respiration as well as protein homeostasis to be triggered during onset of MLL-ENL leukemogenesis in fetal HSPCs. Our data has demonstrated that redox signalling contributes to the regulation of fundamental processes of developmental hematopoiesis and has pinpointed potential targetable redox-sensitive proteins in in utero-initiated MLL-rearranged leukaemia. An H9 human embryonic stem cells cell line was applied to validate data from the primary cells.
Project description:Objective Recent evidence indicates that the adult hematopoietic system is susceptible to diet-induced lineage skewing. It is not known whether the developing hematopoietic system is subject to metabolic programming via in utero high fat diet (HFD) exposure, an established mechanism of adult disease in several organ systems. We previously reported substantial losses in offspring liver size with prenatal HFD. As the liver is the main hematopoietic organ in the fetus, we asked whether the developmental expansion of the hematopoietic stem and progenitor cell (HSPC) pool is compromised by prenatal HFD and/or maternal obesity. Methods We used quantitative assays, progenitor colony formation, flow cytometry, transplantation, and gene expression assays with a series of dietary manipulations to test the effects of gestational high fat diet and maternal obesity on the day 14.5 fetal liver hematopoietic system. Results Maternal obesity, particularly when paired with gestational HFD, restricts physiological expansion of fetal HSPCs while promoting the opposing cell fate of differentiation. Importantly, these effects are only partially ameliorated by gestational dietary adjustments for obese dams. Competitive transplantation reveals compromised repopulation and myeloid-biased differentiation of HFD-programmed HSPCs to be a niche-dependent defect, apparent in HFD-conditioned male recipients. Fetal HSPC deficiencies coincide with perturbations in genes regulating metabolism, immune and inflammatory processes, and stress response, along with downregulation of genes critical for hematopoietic stem cell self-renewal and activation of pathways regulating cell migration. Conclusions Our data reveal a previously unrecognized susceptibility to nutritional and metabolic developmental programming in the fetal HSPC compartment, which is a partially reversible and microenvironment-dependent defect perturbing stem and progenitor cell expansion and hematopoietic lineage commitment. Examination of differentially expressed genes between gestational day 15 (+/- 0.5 days) C57BL/6 mouse fetal livers from diet-induced (60% fat diet) obese or control female mice.
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:Whereas the human fetal immune system is poised to generate immune tolerance and suppress inflammation in utero, an adult-like immune system emerges to orchestrate anti-pathogen immune responses in post-natal life. It has been posited that cells of the adult immune system arise as a discrete ontological “layer” of hematopoietic stem-progenitor cells (HSPCs) and their progeny; evidence supporting this model in humans has, however, been inconclusive. Here, we combine bulk and single-cell transcriptional profiling of lymphoid, myeloid, and HSPCs from fetal, perinatal, and adult developmental stages to demonstrate that the fetal-to-adult transition occurs progressively along a continuum of maturity—with a substantial degree of interindividual variation at the time of birth—rather than via a transition between discrete waves. These findings have important implications in the design of strategies for prophylaxis against infection in the newborn, and for the use of umbilical cord blood (UCB) in the setting of transplantation. Naïve CD4 and CD8 T cells, and CD34+ hematopoietic stem and progenitor cells (HSPCs) were isolated from human samples of three different groups: Fetal (18-23 gestational weeks), full-term newborn (37+ gestational weeks at birth), and adults age 23 to 53. For each group, five independent donors were analyzed, but not all cell types could be sequenced for every patient.
Project description:Whereas the human fetal immune system is poised to generate immune tolerance and suppress inflammation in utero, an adult-like immune system emerges to orchestrate anti-pathogen immune responses in post-natal life. It has been posited that cells of the adult immune system arise as a discrete ontological “layer” of hematopoietic stem-progenitor cells (HSPCs) and their progeny; evidence supporting this model in humans has, however, been inconclusive. Here, we combine bulk and single-cell transcriptional profiling of lymphoid, myeloid, and HSPCs from fetal, perinatal, and adult developmental stages to demonstrate that the fetal-to-adult transition occurs progressively along a continuum of maturity—with a substantial degree of interindividual variation at the time of birth—rather than via a transition between discrete waves. These findings have important implications in the design of strategies for prophylaxis against infection in the newborn, and for the use of umbilical cord blood (UCB) in the setting of transplantation. Naïve CD4 and CD8 T cells, and CD34+ hematopoietic stem and progenitor cells (HSPCs) were isolated from human samples of three different groups: Fetal (18-23 gestational weeks), full-term newborn (37+ gestational weeks at birth), and adults age 23 to 53. For each group, five independent donors were analyzed, but not all cell types could be sequenced for every patient.
Project description:Whereas the human fetal immune system is poised to generate immune tolerance and suppress inflammation in utero, an adult-like immune system emerges to orchestrate anti-pathogen immune responses in post-natal life. It has been posited that cells of the adult immune system arise as a discrete ontological “layer” of hematopoietic stem-progenitor cells (HSPCs) and their progeny; evidence supporting this model in humans has, however, been inconclusive. Here, we combine bulk and single-cell transcriptional profiling of lymphoid, myeloid, and HSPCs from fetal, perinatal, and adult developmental stages to demonstrate that the fetal-to-adult transition occurs progressively along a continuum of maturity—with a substantial degree of interindividual variation at the time of birth—rather than via a transition between discrete waves. These findings have important implications in the design of strategies for prophylaxis against infection in the newborn, and for the use of umbilical cord blood (UCB) in the setting of transplantation. Naïve CD4 and CD8 T cells, and CD34+ hematopoietic stem and progenitor cells (HSPCs) were isolated from human samples of three different groups: Fetal (18-23 gestational weeks), full-term newborn (37+ gestational weeks at birth), and adults age 23 to 53. For each group, five independent donors were analyzed, but not all cell types could be sequenced for every patient.
Project description:We developed a novel scRNAseq analysis pipeline called SingCellaR. This tool provides a comprehensive set of the functionalities necessary for analysis of large-scale single cell datasets generated by different single-cell technologies. The utility of SingCellaR is illustrated by analysis of a unique dataset capturing hematopoietic stem/progenitor cells (HSPC) across different stages of human ontogeny, from early fetal liver to adult bone marrow, identifying developmental stage- and site-specific differences in the HSPC compartment.