Wnt signaling in hematopoietic development

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的生命是骨髓移植治疗的疗效基础 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，这将另外绕过免疫排斥和同种异体反应，这两个主要问题 在诊所里。 拟议的合作研究利用了两名首席调查员的专业知识，具有互补性 研究兴趣和技能包括干细胞生物学、斑马鱼遗传和发育、小鼠造血干细胞生物学、 造血发育、WNT生物学和生物化学。使用斑马鱼和hPSCs作为模型系统， 他们试图识别和描述在早期指导造血发展的分子线索。 胚胎阶段，重点是Wnt信号的作用。拟议的研究将以他们的发现为基础。 Wnt9a/Frizzled9/EGFR调节的信号轴对于HSC的出现和 在脊椎动物门中扩张。这项提议将利用斑马鱼体内和体外的血统追踪方法。 HPSCs的分化方案结合单细胞测序方法确定分子 这一要求的机制，并提供了一个新的水平的理解如何后外侧中胚层 被指示生成HSC。 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。这项研究的顺利完成将产生深远的影响 关于HSC的派生和扩展，从而将有助于克服目前 有效治疗需要骨髓移植治疗的疾病。

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 proposed collaborative research leverages the expertise of two Principal Investigators with complementary research interests and skills in stem cell biology, zebrafish genetics and development, murine HSC biology, hematopoietic development, and Wnt biology and biochemistry. Using zebrafish and hPSCs as model systems, they seek to identify and characterize the molecular cues that direct hematopoietic development during early embryonic stages, with an emphasis on the role of Wnt signaling. The proposed studies will build on their finding that a signaling axis regulated by Wnt9a/Frizzled9/EGFR is specifically required for HSC emergence and expansion across vertebrate phyla. 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.