Effects of EDAG knockdown on gene expression profiles in human erythroid cells
ABSTRACT: To investigate the effects of EDAG knockdown on gene exrpession profile in human cord blood CD34+ cells with EPO treatment with microarray assay. Freshly isolated human cord blood CD34+ cells were pre-activated for 24 hours and then infected with EDAG RNAi lentivirus or control lentivirus for 3 times within 24 hours. Then the cells were cultured in the presence of EPO to induce erythroid differentiation. Four days later, the cells were harvested for microarray test. The microarray showed that 3149 differentially expressed genes in siEDAG group compared to control group.The altered genes were associated with gene exrpression, cell cycle and hematopoietic differentiation. These data show that EDAG knckdown led to down-regulation of erythroid genes which are activated by GATA1. Human CD34+ cells infected with EDAG RNAi or control lentivirus were treated with EPO (5U/ml) for 4 days and gene expression were measured using Agilent human whole Genome 8*60K array. Two replicates.
Project description:In order to investigate the mechanism whereby TEL-PDGF-beta (ETV6-PDGFRB) interferes with human hematopoietic progenitors proliferation and differentiation, we analyzed the gene expression response downstream this oncogene. CD34+ cells infected with lentivirus coding for TEL-PDGFRb were cultured for 7 days in the absence of cytokines. Using Affymetrix microarrays, we compared gene expression in these cells and in cells treated for 4 h with low dose imatinib (Glivec), a potent PDGFR inhibitor, to switch off TEL-PDGFRb signaling. This experiment was performed in three biological replicates. In each replicate gene expression profiling from CD34+ HSCs expressing TEL-PDGFRb untreated with Glivec was compared to the corresoniding treated condition. Total RNA were extracted from transduced CD34+ cells using Trizol reagent (Invitrogen) and the RNeasy kit (QIAGEN).
Project description:Reintroduction of CEBPA in MN1-overexpressing hematopoietic cells prevents their hyper-proliferation and restores myeloid differentiation. Forced expression of MN1 in primitive mouse hematopoietic cells causes acute myeloid leukemia and impairs all-trans retinoic acid (ATRA) induced granulocytic differentiation. Here, we studied the effects of MN1 on myeloid differentiation and proliferation using primary human CD34+ hematopoietic cells, lineage depleted mouse bone marrow cells, and bipotential (granulocytic/monocytic) human AML-cell lines. We show that exogenous MN1 stimulated the growth of CD34+ cells, which was accompanied by enhanced survival and increased cell cycle traverse in cultures supporting progenitor cell growth. Forced MN1 expression impaired both granulocytic and monocytic differentiation in vitro in primary hematopoietic cells and AML cell lines. Endogenous MN1 expression was higher in human CD34+ cells compared to both primary and in vitro differentiated monocytes and granulocytes. Microarray and real time RT-PCR analysis of MN1-overexpressing CD34+ cells showed down regulation of CEBPA and its downstream target genes. Re-introduction of conditional and constitutive CEBPA overcame the effects of MN1 on myeloid differentiation and inhibited MN1-induced proliferation in vitro. These results indicate that down regulation of CEBPA activity contributes to MN1-modulated proliferation and impaired myeloid differentiation of hematopoietic cells Human BM derived CD34+ cells (Stemcell Technologies, Vancouver, BC, Canada) were expanded for 2 days and transduced with MSCV-IRES-GFP or MSCV-MN1-IRES-GFP retrovirus for another 2 days. One day later RNA was isolated from GFP+/CD34+ FACS-sorted cells using Trizol (Sigma) and samples were subjected to micro array analysis following Affymetrix protocols (Affymetrix, Santa Clara, CA) using the GeneChip Human U133 Plus 2.0 array
Project description:Hematopoietic stem and progenitor cells (HPCs) can be maintained in vitro, but the vast majority of their progeny loses “stemness” during culture. In this study, we have analyzed DNA methylation (DNAm) profiles of freshly isolated CD34+ cells and upon expansion on either tissue culture plastic (TCP) or mesenchymal stromal cells (MSCs). DNAm profiles of expanded CD34+ versus CD34- subsets reflected hematopoietic differentiation, whereas culture on TCP or MSCs had little impact. Notably, all cultured HPCs - even those which remained CD34 positive - acquired significant DNA-hypermethylation, particularly in up-stream promoter regions, shore-regions of CpG islands, and binding sides for PU.1 and RUNX1. Our results point to a coordinated epigenetic process which needs to be controlled to enhance self-renewal of HPCs in vitro. 12 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
Project description:The global gene expression profiles of human umbilical cord blood and adult bone marrow CD34+CD33-CD38-Rho(lo)c-kit+ cells, enriched for hematopoietic stem/progenitor cells (HSC) with CD34+CD33-CD38-Rho(hi) cells, enriched in committed hematopoietic progenitor cells (HPC), were compared to identify candidate regulators of HSC self-renewal versus differentiation fate decisions.
Project description:Human CD34+ cells were cultured shortly in the presence of cytokines then with a gene transfer lentiviral vector (LV) expected to transduce cells but to have otherwise limited biological effects on the cells. At the end of the culture, the population of cells remained largely similar at the phenotypic level but some epigenetic changes were evident. Exposure of CD34+ cells to cytokines caused genome-wide DNA methylation changes. Surprisingly, the LV caused additional and distinct effects. Large-scale genomic DNA methylation analysis showed that balanced methylation changes occurred in about 200 genes following culture of CD34+ cells in the presence of cytokines but 900 genes were modified following addition of the LV, predominantly increasing CpG methylation. Epigenetic effects resulting from ex vivo culture and from the use of LV may constitute previously unsuspected sources of biological effects in stem cells and may provide new biomarkers to rationally optimize gene and cell therapy protocols. 3 replicates of control unstimulated (Group 1), cytokine stimulated, cytokine strimulated and treated with polybren and cytokine stimulated and transduced with lentiviral vector coding for GFP in the presence of polybren were analysed
Project description:Cord blood hematopoietic stem cells (CB-HSCs) are an outstanding source for transplantation approaches. However, the amount of cells per donor is limited and culture expansion of CB-HSCs is accompanied by a loss of engraftment potential. In order to analyze the molecular mechanisms leading to this impaired potential we profiled global and local epigenotypes during the expansion of human CB hematopoietic stem and progenitor cells (HPSCs). Human CB-derived CD34+ cells were cultured in serum-free medium together with SCF, TPO, FGF, with or without Igfbp2 and Angptl5 (STF/STFIA cocktails). As compared to the STF cocktail, the STFIA cocktail maintains in vivo repopulation capacity of cultured CD34+ cells. Upon expansion, CD34+ cells genome-wide remodel their epigenotype and depending on the cytokine cocktail, cells show different H3K4me3 and H3K27me3 levels. Expanding cells without Igfbp2 and Angptl5 leads to higher global H3K27me3 levels. ChIPseq analyses reveal a cytokine cocktail-dependent redistribution of H3K27me3 profiles. Inhibition of the PRC2 component EZH2 counteracts the culture-associated loss of NOD scid gamma (NSG) engraftment potential. Collectively, our data reveal chromatin dynamics that underlie the culture-associated loss of engraftment potential. We identify PRC2 component EZH2 as being involved in the loss of engraftment potential during the in vitro expansion of HPSCs. 6 samples were hybridized GeneChip Human Gene 1.0 ST Arrays (Affymetrix)
Project description:Human cord blood CD34+ cells transduced with control of IK6 lentivirus were transplanted into NSG mice. Control and IK6 transduced CD34+38- progeny were acquired 10 weeks later by FACS Comparison of control and IK6+ human CD34+38- progenitor cells
Project description:Homodimerization of Mpl can also be accomplished in the absence of Tpo, by binding of a synthetic ligand (Chemical inducer of dimerization, CID) to a constitutively expressed fusion protein F36VMpl consisting of a ligand binding domain (F36V) and the intracellular signaling domain of Mpl. In contrast to Tpo stimulation, F36VMpl dimerization in human CD34+ progenitor cells generates robust erythropoiesis. Microarray gene expression profiling of progenitors demonstrated that F36VMpl dimerization, but not Tpo, results in upregulation of critical erythroid genes. CD34+ cord blood cells were transduced with F36VMpl-GFP (GFP reporter gene) and cultured on MS-5 stroma for 7 days in the presence of CID, Tpo, Epo or no factors (no CID, negative control). CD34+GFP+ cells were sorted on day 7 and subjected to microarray (n=3 independent experiments).
Project description:The near-normalization of constitutive cytokine and matrix release following rescue by HPS1 transduction of HPM cells suggests that HPS-1 HuMCs may contribute to pulmonary fibrosis and constitute a target for therapeutic intervention. Microarray analysis of HPS-1 HuMCs and non-transduced HPM cells confirmed upregulation of differentially expressed genes involved in fibrogenesis and degranulation. Six HPS-1 patients and five healthy controls were studied following informed consent. One typical HPS-1 HuMC culture at 5-6 weeks was eventually overgrown by a population of smaller, rapidly dividing cells. Analysis of differential gene expression from 8 wk old control and HPS-1 HuMCs and HPM cells was performed using cDNA generated from cultured cells.