Project description:The objective of the study is to identify the genes regulated by STAT5 in very primitive human hematopoietic stem progenitor cells (HSPCs). We used Affymetrix Human Genome U133 Plus 2.0 microarrays to investigate gene expression in human CD34+CD38- HSPC upon expression of STAT5 or control luciferase shRNA-encoding vectors.
Project description:The comparative characterization of hematopoietic stem cells from healthy stem cell donors and patients with acute myeloid leukemia on a proteome level has the potential to reveal differentially regulated proteins which might be candidates for specific immunotherapy target molecules. Exemplarily, we analyzed the proteome of the cytosolic and the membrane fraction of CD34 and CD123 co-expressing FACS-sorted leukemic progenitors from five patients with acute myeloid leukemia employing mass spectrometry. As a reference, CD34+CD123+ normal hematopoietic progenitor cells from five healthy stem cell donors were analyzed. In this TMT 10-plex labeling based approach 2068 proteins were identified with 256 proteins differentially regulated in one or both cellular compartments. This study demonstrates the feasibility of a mass spectrometry based proteomic approach to detect differentially expressed proteins in two compartment fractions of leukemic stem cells as compared to their healthy stem cell counterparts.
Project description:AML1-ETO expression in normal human umbilical cord blood CD34+ cells leads to long-term proliferation of an early self-renewing primitive progenitor cell with multilineage potential and stem cell ability, but these cells do not induce leukemia in immunodeficient mice. This comparative microarray study was initiated to determine the differences in the transcriptome of AML-ETO-expressing CD34+ cells after extended culture in vitro, using normal cord blood cells expanded for 6-8 weeks in vitro and subsequently purified for the CD34+ population as the control comparison. Keywords: Disease state analysis; comparison of changes in transcriptome due to long-term AML1-ETO expression in normal human hematopoietic CD34+ progenitor cells
Project description:RNA-seq analysis was performed to compare differentially expressed genes in freshly isolated and ex-vivo cultured human cord blood CD34+ cells. Mitochondrion related genes are upregulated in CD34+ hematopoietic stem and progenitor cells upon ex vivo culture. In vivo transplantation experiments demonstrate that stemness of CD34+ cells is significantly decreased due to oxidative stress induced by ex vivo culture.
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:To better understand the early events regulating lineage-specific hematopoietic differentiation, we analyzed the transcriptional profiles of CD34+ human hematopoietic stem and progenitor cells (HSPCs) subjected to differentiation stimulus. CD34+ cells were cultured for 12 and 40 hours in liquid cultures with supplemented media favoring myeloid or erythroid commitment. Serial analysis of gene expression (SAGE) was employed to generate four independent libraries. CD34+ Hematopoietic Stem Progenitor Cells with no differentiation stimulus were used as a control library.
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.
Project description:Human embryonic stem cells (hESCs) are a powerful tool for modeling regenerative therapy. To search for the genes that promote hematopoietic development from human pluripotent stem cell, we overexpressed a list of hematopoietic regulator genes in human pluripotent stem cell-derived CD34+CD43- endothelial cells (ECs) enriched in hemogenic endothelium. Among genes tested, only SOX17, a gene encoding a transcription factor of the SOX family, promoted cell growth and supported expansion of CD34+CD43+CD45-/low cells expressing a hemogenic endothelial maker VE-cadherin. SOX17 was highly expressed in CD34+CD43- ECs but at a low level in CD34+CD43+CD45- pre-hematopoietic progenitor cells (pre-HPCs) and CD34+CD43+CD45+ HPCs. SOX17-overexpressing cells formed sphere-like colonies and generated few hematopoietic progenies. However, they retained hemogenic potential and gave rise to hematopoietic progenies upon inactivation of SOX17. Global gene expression analyses revealed that the CD34+CD43+CD45-/low cells expanded upon overexpression of SOX17 are hemogenic endothelium-like cells developmentally placed between ECs and pre-HPCs. Of interest, SOX17 also reprogrammed both pre-HPCs and HPCs into hemogenic endothelium-like cells. Genome-wide mapping of SOX17 revealed that SOX17 directly activates transcription of key regulator genes for vasculogenesis, hematopoiesis, and erythrocyte differentiation. Depletion of SOX17 in CD34+CD43- ECs severely compromised their hemogenic activity. These findings suggest that SOX17 plays a critical role in priming hemogenic potential in ECs, thereby regulates hematopoietic development from hESCs. This SuperSeries is composed of the SubSeries listed below.