Defining regulators of hematopoietic stem cell self-renewal and lineage potential

定义造血干细胞自我更新和谱系潜力的调节因子

• 批准号: 9911115
• 负责人: Atesh K Worthington
• 金额: $ 3.78万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA CRUZ
• 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 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9911115
• 关键词: ATAC-seq; Adult; Amaze; CRISPR interference; Cell Lineage; Cell physiology; Cells; Chromatin; Clinical; Development; Elements; Epigenetic Process; Fetal Development; Fetal Liver; Genes; Genetic Transcription; Goals; Hematologic Neoplasms; Hematological Disease; Hematopoietic; Hematopoietic stem cells; In Situ; Inherited; Life; Lymphoid; Molecular; Outcome; Output; Population; Prevention; Property; Regulation; Regulator Genes; Regulatory Element; Stem cell transplant; Stress; Testing; Therapeutic; Transplantation; base; cell type; clinical efficacy; epigenetic memory; experimental study; fetal; hematopoietic stem cell fate; hematopoietic stem cell self-renewal; improved; insight; loss of function; mouse model; novel; novel strategies; post-transplant; reconstitution; regenerative; self-renewal; stem cell biology; stem cell population; stem cells; tool; transcriptome; transcriptome sequencing

PROPOSAL SUMMARY The goal of my proposal is to understand the mechanisms regulating the self-renewal and lineage potential of hematopoietic stem cells (HSCs) and how HSC fate and function can be controlled by manipulation of epigenetic parameters. The context of my study is unique, because we have discovered a fetal, developmentally restricted HSC (drHSC) with unusual properties: the drHSCs are capable of long-term, multilineage reconstitution (LTMR) upon serial transplantation, but do not persist into adulthood during normal development. The ability of drHSCs to self-renew and persist is therefore induced upon transplantation. Further, while capable of generating all the “traditional” hematopoietic cell types investigated to date, the drHSCs are lymphoid biased and have superior B1a cell reconstitution capacity compared to the co-existing fetal liver (FL) HSCs. Amazingly, the lymphoid bias and B1a capacity are retained over many months in serial transplantation experiments. The two core properties that define functional HSCs – self-renewal and lineage potential – are therefore uniquely regulated in drHSCs. I will leverage these unique properties to understand the molecular and epigenetic mechanisms that govern HSC fate and function, and how these mechanisms are both stable (as in the case of drHSC lineage potential) and dynamic (as in the case of induced persistence). I will also take advantage of my ability to isolate three distinct populations of HSCs: the drHSCs, co-existing fetal HSCs (fHSCs), and adult HSCs (aHSCs). Together, this will enable me to ask fundamental questions in HSC biology from a unique perspective and with novel strategies: How is long-term persistence of drHSCs induced upon transplantation, whereas their lineage bias is retained? Is lineage potential exclusively a loss-of-function phenomenon or do adult HSCs have differentiation capabilities that fetal HSCs lack? If so, how are these gained? How can one HSC population be “reprogrammed” into another HSC subtype? I propose to pursue these questions by assessing epigenetic and transcriptome dynamics (Aim 1), and by functionally manipulating HSC potential using CRISPRi mouse models (Aim 2). Outcomes from this proposal will be provide fundamental proof-of-concept experiments for HSC manipulation with the long-term goal of applying these tools to increase the efficacy of stem cell transplant therapies.

提案摘要 我建议的目标是了解调节自我更新和谱系潜力的机制 造血干细胞 (HSC) 以及如何通过操纵来控制 HSC 的命运和功能 表观遗传参数。我的研究背景是独特的，因为我们发现了一个胎儿， 发育受限 HSC (drHSC) 具有不寻常的特性：drHSC 能够长期、 连续移植后的多谱系重建（LTMR），但在正常情况下不会持续到成年期 发展。因此，drHSC 的自我更新和持续能力是在移植后诱导的。 此外，虽然能够产生迄今为止研究的所有“传统”造血细胞类型， drHSC 具有淋巴偏向性，与共存的 B1a 细胞相比具有卓越的 B1a 细胞重建能力 胎儿肝脏 (FL) HSC。令人惊讶的是，淋巴偏向和 B1a 容量连续几个月得以保留 移植实验。定义功能性 HSC 的两个核心特性——自我更新和 谱系潜力——因此在 drHSC 中受到独特的调节。我将利用这些独特的属性 了解控制 HSC 命运和功能的分子和表观遗传机制，以及这些机制如何 机制既是稳定的（如 drHSC 谱系潜力的情况）又是动态的（如 诱导持久性）。我还将利用我的能力来分离三个不同的 HSC 群体： drHSC、共存胎儿 HSC (fHSC) 和成人 HSC (aHSC)。总之，这将使我能够问 从独特的角度和新颖的策略解决 HSC 生物学的基本问题：长期如何 移植后诱导的 drHSC 是否持续存在，而其谱系偏向却被保留？是血统 潜在的完全功能丧失现象还是成人 HSC 具有胎儿的分化能力 HSC 缺乏？如果是的话，这些是如何获得的？如何将一个 HSC 群体“重新编程”为另一个 HSC 亚型？我建议通过评估表观遗传和转录组动力学来解决这些问题（目标 1）， 以及使用 CRISPRi 小鼠模型功能性操纵 HSC 潜力（目标 2）。由此产生的结果 该提案将为 HSC 操作提供长期的基本概念验证实验 应用这些工具来提高干细胞移植疗法的功效的目标。