Project description:In the mouse embryo during midgestation, hematopoietic stem cells (HSCs) are generated from aortic endothelium through the transdifferentiation process known as endothelial-to-hematopoietic transition, or EHT. During EHT, flat-shaped hemogenic endothelium transform into round-shaped hematopoietic cells, which subsequently form cell aggregates, called hematopoietic clusters. To understand HSC specification during ontogeny and to search for nascent HSC markers, we performed single-cell microarray analysis of developing HSC populations.
Project description:DNA methylation is essential for mammalian development and plays crucial roles in a variety of biological processes. The DNA methyltransferase Dnmt1 serves to maintain parental cell methylation patterns on daughter DNA strands in mitotic cells, however, the precise role of Dnmt1 in regulation of quiescent adult stem cells is not known. To examine the role of Dnmt1 in adult hematopoietic stem cells (HSCs), we conditionally disrupted Dnmt1 in the hematopoietic system. We used microarrays to profile the global gene expression program in hematopoietic stem and progenitor cells following deletion of Dnmt1.
Project description:Polycythemia vera (PV) is a myeloproliferative neoplasm (MPN) characterized by hyper-proliferation of the erythroid, megakaryocytic and granulocytic lineages and the presence of an activating mutation in JAK2. To elucidate mechanisms that regulate PV stem cells, we applied a newly developed data-independent acquisition (DIA) mass spectrometry (MS) technology to purified hematopoietic stem and progenitor cell (HSPC) subpopulations of patients with chronic and progressed PV. Proteomic analyses were supplemented by RNA-sequencing (RNA-seq) and identified targets validated by flow cytometry and functional in vitro assays.
Project description:DNA methylation is essential for mammalian development and plays crucial roles in a variety of biological processes. The DNA methyltransferase Dnmt1 serves to maintain parental cell methylation patterns on daughter DNA strands in mitotic cells, however, the precise role of Dnmt1 in regulation of quiescent adult stem cells is not known. To examine the role of Dnmt1 in adult hematopoietic stem cells (HSCs), we conditionally disrupted Dnmt1 in the hematopoietic system. We used microarrays to profile the global gene expression program in hematopoietic stem and progenitor cells following deletion of Dnmt1. Dnmt1 was conditionally deleted in the hematopoietic system by injections of poly(I)poly(C) to induce Cre expression from the Mx-Cre transgene. Control mice were also injected with poly(I)poly(C) but do not carry the Mx-Cre transgene. Four days after completion of poly(I)poly(C) injections, bone marrow was harvested from the mice, antibody-mediated magnetic bead selection was used to remove cells expressing mature lineage markers, and the resulting lineage-depleted cells were stained with fluorochrome-conjugated antibodies against the surface receptors c-Kit, Sca-1 and CD34. Populations of LT-HSCs, MPPs and myeloid progenitors were FACS sorted, RNA was extracted and amplified from these sorted populations and hybridized to Affymetrix microarrays to compare changes in gene expression induced by conditional knockout of Dnmt1 compared to control in each of the three cell populations. There are 2 biological replicates for the LT-HSCs and MPPs and 3 biological replicates for the myeloid progenitors.