Molecular and functional dissection of the zebrafish hematopoietic stem cell niche

项目摘要/摘要： 造血干细胞(HSCs)是血液中所有终末分化细胞的来源。造血干细胞的能力 重建这些血细胞谱系是骨髓移植治疗效果的基础。 用于治疗各种血液疾病，包括白血病、贫血和自身免疫。虽然这是一个 尽管已经建立了有效的治疗方法，但三分之二需要移植的患者缺乏匹配的捐赠者。 因此，替代的治疗性造血干细胞来源将是该领域的福音。人多能干细胞 (HPSCs)代表了基于细胞的治疗的潜在来源，包括衍生患者特有的 可移植的造血干细胞，这将额外绕过免疫排斥和同种异体反应，这两个主要 诊所里的问题。 拟议研究的目标是扩大我们对一种新的体节动物种群的初步观察-- 来源的内皮细胞(SDECs)。值得注意的是，这些细胞只迁移到新生的背主动脉并发挥作用。 作为随后出现的造血干细胞的发育利基。SDEC的特性将提供 更深入地了解控制体内HSC发育的线索。所取得的基本发现 在这些研究的过程中，最终将提供从hPSC派生HSC的策略。这项建议 将利用斑马鱼的谱系追踪方法和hPSCs的体外分化方案 单细胞测序方法，以确定这一要求的分子机制，并提供 对后外侧中胚层如何被指示生成造血干细胞的理解达到了一个新的水平。 这些研究的长期目标是更好地了解造血干细胞如何在胚胎中发育。 以便将此信息转换为hPSC。这项研究的成功完成将具有深远的意义 对HSC派生和扩展的影响，从而将有助于克服目前的障碍 需要骨髓移植治疗的疾病的有效治疗。

Project Summary/Abstract: Hematopoietic stem cells (HSCs) give rise to all terminally differentiated cells in the blood. The ability of HSCs to reconstitute these blood cell lineages for life underlies the efficacy of bone marrow transplantation therapy for treatment of various blood disorders, including leukemias, anemia, and autoimmunity. Although this is an established and effective treatment, two-thirds of patients in need of a transplant lack a matched donor. Therefore, alternative sources of therapeutic HSCs would be a boon to the field. Human pluripotent stem cells (hPSCs) represent a potential source for cell-based therapies, including the derivation of patient-specific transplantable HSCs, which would additionally circumvent immune rejection and alloreactivity, both major issues in the clinic. The goal of the proposed research is to extend our preliminary observations on a novel population of somite- derived endothelial cells (SDECs). Of note, these cells migrate exclusively to the nascent dorsal aorta and act as a developmental niche for the subsequent emergence of HSCs. Characterization of SDECs will provide a deeper understanding of the cues that govern HSC development in vivo. The fundamental discoveries made in the course of these studies will ultimately inform derivation strategies of HSCs from hPSCs. This proposal will leverage lineage tracing methods in zebrafish and in vitro differentiation protocols of hPSCs combined with single-cell sequencing approaches to determine the molecular mechanisms of this requirement, and to provide a new level of understanding of how posterior lateral mesoderm is instructed to generate HSCs. The long-term goal of these studies is to gain a better understanding of how HSCs develop in the embryo in order to translate this information to hPSCs. Successful completion of this research will have a profound impact on HSC derivation and expansion, and thereby will be instrumental in overcoming current obstacles to the effective treatment of diseases requiring bone marrow transplant therapy.