Hematopoietic Stem Cell Biology

造血科的这个项目专注于造血干细胞(HSC)的基础生物学。HSC是一种罕见的自我更新细胞群，可以在外周血中产生所有细胞。对于患有危及生命的血液病的患者，在切除患病的骨髓后，从健康的、匹配的捐赠者那里移植HSC可能是终生治愈的方法。然而，这些程序中的主要风险是移植数量不足的HSC。我们的目标是了解促进HSC自我更新和抑制HSC分化的过程。通过控制自我更新和分化之间的平衡，我们将能够增加干细胞的数量，从而提高骨髓移植治疗获得性或遗传性造血疾病的有效性。 具体目的1：我们先前已经使用CHIP SEQ来评估EKLF(转录因子)结合在小鼠红系细胞中的作用。我们将使用同样的程序来分析小鼠HSC(Lin-c-kit+Sca-1+)多能祖细胞(Lin-，c-kit+Sca-1-)和红系祖细胞(Lin-，CD71+，GlyA+)的DNA甲基化和组蛋白三甲基化。在对浓缩的DNA片段进行测序后，我们将使用Eland软件将每个序列标签映射到基因组和MACS程序，以确定发生显著浓缩的位置。将分析HSC和祖细胞之间甲基化模式不同的基因座，以确定与HSC分化相关的途径。将进行类似的分析，以确定是什么原因导致红系血统受到限制。 特定目的2：CMML是一种罕见的骨髓衰竭综合征，具有克隆的单核细胞祖细胞(LIN-CD33+CD34+)生长。这种疾病是用DNA甲基化抑制剂5-氮胞苷和组蛋白脱乙酰酶抑制剂治疗的。然而，这些药物的效果是否具体归因于这些药物的所述作用尚不清楚。我们将对用这些药物治疗前后的CMML单核细胞祖细胞的染色质进行三甲基化组蛋白的甲基化下拉和ChIPSeq。我们将分析全基因组的结果，以确定这些药物是否导致最小的、局部的或全球的表观遗传学改变。此外，我们希望将反应与具体的变化联系起来，从而更详细地了解疾病的过程。

This project of the Hematopoiesis Section is focused on the basic biology of hematopoietic stem cells (HSC). HSC are a rare population of self-renewing cells that give rise to all cells in the peripheral blood. For patients with a life-threatening hematologic disease, transplantation of HSC from a healthy closely matched donor after ablation of the diseased bone marrow can be a life long cure. However, the main risk in these procedures is the transplantation of inadequate numbers of HSC. Our goal is to understand the processes that promote HSC self-renewal and inhibit HSC differentiation. By manipulating the balance between self-renewal and differentiation we will be able to increase the number of stem cells and consequently increase the effectiveness of bone marrow transplantation to cure acquired or inherited hematopoietic diseases. Specific Aim 1: We have previously used ChIP Seq to evaluate the role of EKLF (transcription factor) binding in mouse erythroid cells. We will use this same procedure to analyze DNA methylation and histone tri methylation in mouse HSC (Lin- c-kit+ Sca-1 +) multipotent progenitor cells (Lin-, c-kit+ Sca-1-) and erythroid progenitor cells (Lin-, CD71+, GlyA+). After sequencing the enriched DNA fragments, we will use the Eland software to map each sequence tag to the genome and the MACS program to determine where significant enrichment has occurred. Loci at which the methylation pattern differs between HSC and progenitor cells will be analyzed to determine the pathways associated with HSC differentiation. Similar analyses will be performed to determine what causes restriction to the erythroid lineage. Specific Aim 2: CMML is an unusual bone marrow failure syndrome with a clonal out growth of monocyte progenitors (Lin- CD33+ CD34+). This disorder id treated with the DNA methylation inhibitor 5-aza cytidine and histone deacetylase inhibitors. However, whether the effects of these drugs are specifically due to the described actions of these drugs is not known. We will perform methylation pull down and ChIPSeq on tri methylated histones on chromatin extracted from CMML monocyte progenitors before and after treatment with these drugs. We will analyze the genome wide results to determine whether the drugs cause minimal, local or global epigenetic alterations. In addition, we hope to correlate the response with a specific change, allowing a more detailed understanding of the disease process.