GPRASP family as novel regulators in hematopoietic stem cells

GPRASP 家族作为造血干细胞的新型调节因子

• 批准号: 10055579
• 负责人: Antonio Morales-Hernandez
• 金额: $ 9.15万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10055579
• 关键词: Affect; B cell differentiation; B-Lymphocytes; Behavior; Binding; Blood; Bone Marrow Transplantation; CXCR4 gene; Cell Compartmentation; Cell Count; Cell Cycle; Cell Lineage; Cell physiology; Cells; Data; Engraftment; Ensure; Environment; Expression Profiling; Family; Family member; G-Protein-Coupled Receptors; Gene Expression; Genetic; Goals; Hematological Disease; Hematopoiesis; Hematopoietic; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cell heterogeneity; Hematopoietic System; Hematopoietic stem cells; Heterogeneity; High Dose Chemotherapy; Homing; Immunofluorescence Immunologic; Impairment; Individual; Lead; Leukocytes; Life; Link; Lymphoid; Malignant - descriptor; Mediating; Mentors; Modeling; Molecular; Molecular Target; Natural regeneration; Non-Malignant; Organism; Patients; Pharmacology; Phase; Phenotype; Population; Procedures; Production; Proliferating; Protein Family; Protein Sortings; Regulation; Reporter; Resources; Role; Safety; Saint Jude Children' s Research Hospital; Savings; Signal Transduction; Stress; Stromal Cell-Derived Factor 1; Transplantation; Umbilical Cord Blood; Work; cell stroma; curative treatments; differential expression; gene therapy; improved; in vivo; leukemia; novel; novel marker; post-transplant; progenitor; reconstitution; self renewing cell; single cell analysis; stem cells; stemness; success; therapeutic target; tool; trafficking

Project Summary Hematopoietic stem cell (HSC) transplantation (HSCT) represents the only curative therapy for most hematologic disease including leukemia. HSCT requires donor HSCs to engage with the proper supporting niche, survive, proliferate, and differentiate into mature blood lineages. Recent studies suggest that “stress hematopoiesis”, including that which occurs post-HSCT, is subject to distinct regulation compared steady-state hematopoiesis. A better understanding the molecular mechanisms that regulate transplanted HSCs and their engraftment is necessary to improve HSCT, especially in situations where transplant is limited by small cell numbers (e.g. cord blood) or potentially compromised by ex vivo manipulation (e.g. gene therapy). Towards this, the main goal of this project is to identify and characterize novel key intrinsic regulators of HSCT. My work reveals high expression of multiple GPRASPs (G-Protein Coupled Receptor Associated Sorting Proteins) (e.g. Gprasp1 and Gprasp2) in HSCs, relative to downstream progenitors. I have also found that both GPRASP1 and GPRASP2 act as negative regulators of HSCT. Gprasp-deficient HSCs present enhanced homing, survival and quiescence during transplant. This phenotype appears dependent on Cxcr4, a master regulator of HSCs function, whose sequence contains a putative GASP-binding motif. Indeed, ectopic Cxcr4 enhances HSC homing, survival and quiescence during transplant, phenocopying loss of Gprasp1 or Gprasp2. Further, my preliminary studies show that, upon Gprasp1 or Gprasp2 loss, CXCR4 is stabilized and accumulates on HSCs, sensitizing them to SDF-1. CXCR4 has also been implicated in regulating cell-to-cell contact between B-cell progenitors and stroma cells. Interesting, my recent data suggests that GPRASP loss may also perturb B-cell production by blocking the differentiation of lymphoid progenitors. Finally, although HSCs as a population are highly enriched for Gprasp1 and Gprasp2 expression, my recent analyses of single cell gene expression data and single HSCs by immunofluorescence reveals that the expression of these genes is heterogeneous amongst individual HSCs. This differential expression corresponds with distinct gene expression profiles (e.g. stemness, cell cycle, B-cell differentiation). Although clonal analyses have revealed that even highly purified HSCs display diverse differentiation potential, the molecular regulation of this functional heterogeneity is currently poorly understood. Thus, I hypothesize that multiple GPRASP family members regulate HSC transplantation and B-cell differentiation, and correlate with HSC functional heterogeneity. The mentored phase of this proposal will occur at St. Jude Children’s Research Hospital, under Dr. Shannon McKinney-Freeman. In the independent phase, I will confirm and extend my studies of the molecular link between GPRASPs and CXCR4 in HSCT and B-cell differentiation, as well as exploit novel molecular reporters to refine HSC functional heterogeneity. The institutional resources and academic environment and the planned courses outlined in my proposal will ensure my successful transition to independence.

项目概要 造血干细胞 (HSC) 移植 (HSCT) 是大多数血液病的唯一治疗方法 疾病包括白血病。 HSCT 要求供体 HSC 参与适当的支持利基、生存、 增殖并分化成成熟的血统。最近的研究表明“应激造血”， 包括 HSCT 后发生的情况，与稳态造血相比受到不同的调节。 更好地了解调节移植 HSC 及其植入的分子机制是 改善 HSCT 所必需的，特别是在移植受到小细胞数量限制的情况下（例如脐带 血液）或可能因离体操作（例如基因治疗）而受到损害。为此，主要目标是 该项目旨在识别和表征 HSCT 的新型关键内在调节因子。我的作品展现出高表达力 多个 GPRASP（G 蛋白偶联受体相关分选蛋白）（例如 Gprasp1 和 Gprasp2） HSC，相对于下游祖细胞。我还发现 GPRASP1 和 GPRASP2 都起到负面作用 HSCT 的监管者。 Gprasp 缺陷型 HSC 在生命周期中表现出增强的归巢、存活和静止能力 移植。这种表型似乎依赖于 Cxcr4，它是 HSC 功能的主要调节因子，其序列 包含一个假定的 GASP 结合基序。事实上，异位 Cxcr4 增强 HSC 归巢、存活和静止 移植期间，Gprasp1 或 Gprasp2 的表型丢失。此外，我的初步研究表明，根据 Gprasp1 或 Gprasp2 丢失，CXCR4 稳定并在 HSC 上积聚，使它们对 SDF-1 敏感。 CXCR4 还涉及调节 B 细胞祖细胞和基质细胞之间的细胞间接触。 有趣的是，我最近的数据表明，GPRASP 损失也可能通过阻断 B 细胞的产生来扰乱 B 细胞的产生。 淋巴祖细胞的分化。最后，虽然 HSC 作为一个群体高度富集 Gprasp1 和 Gprasp2 表达，我最近对单细胞基因表达数据和单个 HSC 的分析 免疫荧光显示这些基因的表达在各个 HSC 中是异质的。 这种差异表达对应于不同的基因表达谱（例如干性、细胞周期、B 细胞 差异化）。尽管克隆分析表明，即使高度纯化的 HSC 也显示出不同的 分化潜力，目前对这种功能异质性的分子调节知之甚少。 因此，我假设多个 GPRASP 家族成员调节 HSC 移植和 B 细胞 分化，并与 HSC 功能异质性相关。该提案的指导阶段将发生 在圣裘德儿童研究医院，由香农·麦金尼-弗里曼博士领导。在独立阶段，我 将证实并扩展我对 HSCT 和 B 细胞中 GPRASP 和 CXCR4 之间分子联系的研究 分化，以及利用新型分子报告基因来完善 HSC 功能异质性。这 我的提案中概述的机构资源和学术环境以及计划课程将确保 我成功过渡到独立。