Project description:We used ChIP-Seq to map GABP-alpha binding sites in human hematopoietic progenitor cells (HPCs). Coupled with functional assays using GABP-alpha deficient mouse model and bioinformatics analysis, we systematically determined a transcriptional module controlled by GABP in HPCs. Examination of the role of GABP in hematopoietic stem cells
Project description:We used ChIP-Seq to map GABP-alpha binding sites in human hematopoietic progenitor cells (HPCs). Coupled with functional assays using GABP-alpha deficient mouse model and bioinformatics analysis, we systematically determined a transcriptional module controlled by GABP in HPCs.
Project description:Hematopoietic stem and progenitor cells are a rare, self-renewing bone marrow resident population capable of giving rise to all circulating hematopoietic cells. They can be used therapuetically for reconstituting defective or ablated hematopoietic systems following chemotherapy, and for inducing tolerance toward allografts of the same haplotype as the HSC donor. There are several sources for HSCs, such as the adult bone marrow, or umblical cord blood, which is more replete with such HSCs. However, HSCs obtained from such sources may be immunogenic, especially if isolated from adult bone marrow. To overcome this issue, our lab has establsihed human induced pluripotent stem cell-derived HPCs with the hope of creating a nonimmunogenic, readily available and unlimited source of HSCs to use for therapy. The goal of this study was to compare the gene expression profiles of naturally found HSCs (UCB-CD34+ HSCs) and HPCs differentiated from 4 different human iPS cell lines (iPS-HPCs), so as to determine the variation between the four iPS-HPCs and whether there were any differences between these HPCs and naturally found HSCs. We utilized 4 iPS cells for this study (detailed descriptions are provided below). iPS cells were differentiated into hematopoietic progenitor cells by coculture on OP9 stromal cells, followed by enrichment of CD34+ cells through immunomagnetic bead separation. The UCB-CD34+ cells were isolated from frozen cord samples through immunomagnetic bead separation. Total RNA was isolated and human gene Affymetrix ST 1.0 arrays performed at the University of Iowa DNA core facility. Data was analyzed, normalized and plotted on BRB Array Tools.
Project description:Latexin is a hematopoietic stem cells (HSCs) and progenitor cells (HPCs) regulatory gene. Its deletion leads to the expansion of HSC and HPC population. The underlying mechanims are largely unknown. We therefore perfored microarrary analysis in HPCs with (Lxn-/-) and without (wild-type, WT) latexin deletion, and determined genes that were altered by latexin deletion. This led us to identify the molecular mechanims by which latexin regulates HSC function.
Project description:Epigenetic mechanisms including histone modifications have emerged as important factors influencing cell fate determination. The functional role of H3K4 methylation, however, remains largely unclear in the maintenance and differentiation of hematopoietic stem/progenitor cells (HSC/HPCs). Here we show that DPY30, a shared core subunit of the SET1/MLL family methyltransferase complexes and a facilitator of their H3K4 methylation activity, is important for ex vivo proliferation and differentiation of human CD34+ HPCs. DPY30 promotes HPC proliferation by directly regulating the expression of genes critical for cell proliferation. Interestingly, while DPY30 knockdown (KD) in HPCs impaired their differentiation into the myelomonocytic lineage, it potently promoted hemoglobin production and affected the kinetics of their differentiation into the erythroid lineage. In an in vivo model, we show that morpholino-mediated dpy30 KD resulted in severe defects in the development of the zebrafish hematopoietic system, which could be partially rescued by co-injection of dpy30 mRNA. Taken together, our results establish a critical role of DPY30 in the proliferation and appropriate differentiation of hematopoietic progenitor cells as well as in animal hematopoiesis. Finally, we also demonstrate a crucial role of DPY30 in the growth of several MLL1-fusion-mediated leukemia cell lines. Total RNAs from control (scr) or knockdown (hD2, hD5) cells before and after culturing under condition promoting myelomonocytic differentiation were subjected to Illumina microarray analyses.
Project description:Hematopoietic stem and progenitor cells are a rare, self-renewing bone marrow resident population capable of giving rise to all circulating hematopoietic cells. They can be used therapuetically for reconstituting defective or ablated hematopoietic systems following chemotherapy, and for inducing tolerance toward allografts of the same haplotype as the HSC donor. There are several sources for HSCs, such as the adult bone marrow, or umblical cord blood, which is more replete with such HSCs. However, HSCs obtained from such sources may be immunogenic, especially if isolated from adult bone marrow. To overcome this issue, our lab has establsihed human induced pluripotent stem cell-derived HPCs with the hope of creating a nonimmunogenic, readily available and unlimited source of HSCs to use for therapy. The goal of this study was to compare the gene expression profiles of naturally found HSCs (UCB-CD34+ HSCs) and HPCs differentiated from 4 different human iPS cell lines (iPS-HPCs), so as to determine the variation between the four iPS-HPCs and whether there were any differences between these HPCs and naturally found HSCs.