Project description:The associated publication describes a RUNX3-dependent defect in primary human CD34+ HSPC differentiation into the erythroid lineage. This study was designed to determine which genes are potential targets of RUNX3, and could contribute to regulation of erythropoiesis.
Project description:CD34-positive cells from peripheral blood were culture for 5 days in erythroid differentiating medium. Four progenitor stages were sorted by FACS using the established cell surface markers CD34 and CD36 with CD117, CD71, and CD105 (Yan H, Am J Hematol, 2021). A comprehensive analysis of the proteome of these four erythroid progenitor stages was done in quadruplicate using a label free proteomic approach.
Project description:The c-Myb transcription factor is highly expressed in immature hematopoietic cells and down-regulated during differentiation. To define the role of c-Myb in human hematopoietic lineage commitment, we studied the effects of its silencing during the commitment of human CD34+ Hematopoietic stem/progenitor cells. In CD34+ cells c-Myb silencing determined a cell cycle arrest in G0/G1 phase which strongly decreased the clonogenic efficiency, togheter with a reduction of erythroid colonies coupled with an increase of the macrophage and megakaryocyte ones. Moreover, morphological and flow cytometry data supported the preferential macrophage and megakaryocyte differentiation of c-Myb-silenced CD34+ cells. Taken together our data indicate that c-Myb is essential for the commitment along the erythroid and granulocyte lineages but not for the macrophage and megakaryocyte differentiation. Gene expression profiling of c-Myb-silenced CD34+ cells identified some potential c-Myb targets which can account for these effects, to study by Chromatin Immunoprecipitation and Luciferase Reporter Assay.
Project description:Advances in sequencing-based genomic profiling present a new challenge of explaining how changes in DNA/RNA are translated into proteins linking genotypes to phenotypes. The developing erythroid cells require highly coordinated gene expression and metabolism, and serve as a unique model in dissecting regulatory events in development and disease. Here we compare the proteomic and transcriptomic changes in human hematopoietic stem/progenitor cells and lineage-committed erythroid progenitors, and uncover pathways related to mitochondrial biogenesis enhanced through post-transcriptional regulation. Two principal mitochondrial factors TFAM and PHB2 are tightly regulated at the protein level and indispensable for mitochondria and erythropoiesis. mTORC1 signaling is progressively enhanced to promote translation of mitochondrial proteins during erythroid specification. Genetic and pharmacological perturbation of mTORC1 or mitochondria impairs erythropoiesis. Our studies suggest a new mechanism for regulation of mitochondrial biogenesis through mTORC1-mediated protein translation, and may have direct relevance to the hematological defects associated with mitochondrial diseases and aging. Transcriptional profiling in human primary fetal and adult CD34+ hematopoietic stem/progenitor cells (HSPCs) erythroid progenitor cells (ProEs) by RNA-seq analysis.
Project description:The c-Myb transcription factor is highly expressed in immature hematopoietic cells and down-regulated during differentiation. To define the role of c-Myb in human hematopoietic lineage commitment, we studied the effects of its silencing during the commitment of human CD34+ Hematopoietic stem/progenitor cells. In CD34+ cells c-Myb silencing determined a cell cycle arrest in G0/G1 phase which strongly decreased the clonogenic efficiency, togheter with a reduction of erythroid colonies coupled with an increase of the macrophage and megakaryocyte ones. Moreover, morphological and flow cytometry data supported the preferential macrophage and megakaryocyte differentiation of c-Myb-silenced CD34+ cells. Taken together our data indicate that c-Myb is essential for the commitment along the erythroid and granulocyte lineages but not for the macrophage and megakaryocyte differentiation. Gene expression profiling of c-Myb-silenced CD34+ cells identified some potential c-Myb targets which can account for these effects, to study by Chromatin Immunoprecipitation and Luciferase Reporter Assay. To maximize siRNA transfection efficiency, we utilized the NucleofectorTM technology (Amaxa). CD34+ cells were transfected with a mixture of 3 siRNAs targeting c-Myb mRNA and with a non-targeting siRNA as a negative control. The expression level of c-Myb protein on control cells (MOCK and negative control treated cells) and MYBsiRNA treated cells was assessed by Western Blot at 24 and 48h post-nucleofection.
Project description:Exosc8 and Exosc9 are components of the exosome that establish a barricade to erythroid maturation. Here, we knocked down Exosc8 in fetal liver-derived erythroid progenitor cells to determine the cohort of Exosc8-regulated genes in erythroid cells. Freshly isolated fetal liver progenitor cells were infected with retrovirus expressing shRNA targeting either luciferase or Exosc8. Total RNA was isolated from these cells after 3 days ex-vivo culture, during which the cells underwent erythroid maturation.
Project description:Exosc8 and Exosc9 are components of the exosome that establish a barricade to erythroid maturation. Here, we knocked down Exosc8 in fetal liver-derived erythroid progenitor cells to determine the cohort of Exosc8-regulated genes in erythroid cells.
Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.
Project description:Alpha lipoic acid is reported to inhibit neutrophil lineage determination by targeting transcription factor ELK1 in granulocyte-monocyte progenitors. Here, we provide new evidence of alpha lipoic acid in promoting erythroid differentiation by targeting transcription factor ELK1 in CD34+CD371– hematopoietic stem progenitor cells. Over expression of both L-ELK1 and S-ELK1 greatly inhibit erythroid cell differentiation, but not knocking down of ELK1. Thus, RNAseq of CD34+CD123+CD38+CD371– HSPCs is performed to dissect the molecular mechanism of ELK1 in blocking erythrocyte differentiation.