JAK/STAT Signaling in Hematopoietic Stem Cells

造血干细胞中的 JAK/STAT 信号传导

• 批准号: 6829142
• 负责人: Kevin D Bunting
• 金额: $ 25.09万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6829142
• 关键词: JAK kinase; apoptosis; biological signal transduction; bone marrow; cell cycle; cell differentiation; cell growth regulation; cell proliferation; cell surface receptors; cytokine; enzyme activity; flow cytometry; fluorescent dye /probe; gene expression; gene induction /repression; hematopoiesis; hematopoietic stem cells; hematopoietic tissue transplantation; laboratory mouse; polymerase chain reaction; protein structure function; stem cell transplantation; terminal nick end labeling; tissue /cell culture; transcription factor

DESCRIPTION (provided by applicant): The long-term objectives of this work are to identify and characterize genes that may play important roles in both normal and malignant hematopoiesis. Specifically, we are interested in defining regulators of hematopoietic stem cell (HSC) self-renewal versus differentiation cell fate decisions. HSCs are potentially useful for bone marrow (BM) transplantation for genetic disease and cancer, as targets for gene therapy, and as precursors for generation of blood cell products in vitro. Ex vivo expansion of HSCs that maintain primitive properties and functional activity continues to be an important research objective, considering the number of potential applications for use of HSCs. Growth factor signal transduction pathways are known to affect HSC differentiation along specific lineages by acting as survival factors to prevent apoptosis and by imparting a proliferative signal. Additional modulation of interactions of HSCs with the BM stromal microenvironment can be caused by growth factor stimulation. Our goal for this project is to determine the requirement for the JAKISTAT signal transduction pathway in the response of HSCs to specific growth factors that can activate STATs and also maintain HSC activity during short-term ex vivo culture. Multiple signal transduction pathways could be utilized in HSCs following ligand binding to the cell surface receptor and therefore these pathways could be redundant. For this reason, the role of STATs in primitive levels of hematopoiesis cannot be predicted from biochemical analysis of differentiated cells. Our initial studies have revealed that stem cells from mice lacking STAT5a and STAT5b expression show a marked deficiency in competitive long-term repopulating activity without a reduction in the absolute stem cell number. However, it needs to be determined whether the defect is related to cell cycle induction, apoptosis, or alteration in homing/engraftment ability. We propose to utilize molecular genetic approaches such as retroviral-mediated gene transfer and homozygous gene disruption in mice to characterize and distinguish the functional roles of STAT3 and STAT5 in hematopoietic stem cell function. The following specific aims will be addressed in this study. 1) We will determine the role of STAT5 in growth factor signaling pathways that are active in hematopoietic stem cells. 2) We will determine the role of STAT3 in growth factor signaling pathways that are active in hematopoietic stem cells. Altogether, this work will provide insight into the basic biology of HSCs and perhaps ultimately lead to novel methods for expansion of transplantable stem cells in vitro for therapeutic approaches that could be used clinically.

描述（由申请人提供）：这项工作的长期目标是 识别和表征可能在正常情况下发挥重要作用的基因 和恶性造血。具体来说，我们有兴趣定义 造血干细胞 (HSC) 自我更新与分化的调节因子 细胞命运决定。 HSC 对骨髓 (BM) 具有潜在用途 遗传病和癌症的移植作为基因治疗的目标， 并作为体外生成血细胞产物的前体。离体 维持原始特性和功能活性的 HSC 扩展 考虑到数量，仍然是一个重要的研究目标 HSC 的潜在应用。生长因子信号转导 已知途径影响 HSC 沿特定谱系的分化 作为生存因子以防止细胞凋亡并通过赋予 增殖信号。 HSC 与 BM 相互作用的额外调节 基质微环境可由生长因子刺激引起。我们的目标 该项目的目的是确定 JAKISTAT 信号的要求 HSCs 对特定生长因子的反应中的转导途径 可以激活 STATs 并在短期体外维持 HSC 活性 文化。 HSC 可利用多种信号转导途径 配体与细胞表面受体结合后，因此这些 路径可能是多余的。因此，STAT 在原始数据中的作用 造血水平无法通过生化分析预测 分化的细胞。我们的初步研究表明，干细胞来自 缺乏 STAT5a 和 STAT5b 表达的小鼠在 竞争性长期再繁衍活动，且绝对数量不减少 干细胞数量。但需要确定是否存在缺陷 与细胞周期诱导、细胞凋亡或归巢/植入改变相关 能力。我们建议利用分子遗传学方法，例如 逆转录病毒介导的基因转移和小鼠纯合基因破坏 描述并区分 STAT3 和 STAT5 的功能作用 造血干细胞功能。将解决以下具体目标 在这项研究中。 1）我们将确定STAT5在生长因子中的作用 造血干细胞中活跃的信号通路。 2）我们会 确定 STAT3 在活跃的生长因子信号通路中的作用 在造血干细胞中。总而言之，这项工作将提供对 HSC 的基础生物学，也许最终会带来新的方法 体外扩增可移植干细胞用于治疗方法 可以用于临床。