The role of NPM1 in preserving a hematopoietic stem cell identity

NPM1 在保持造血干细胞身份中的作用

• 批准号: 10641005
• 负责人: Thelma Escobar
• 金额: $ 20.22万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-08 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10641005
• 关键词: Acute Myelocytic Leukemia; Adult; Adult Acute Myeloblastic Leukemia; Affinity Chromatography; Applications Grants; Auxins; Biogenesis; Biology; Cell Cycle; Cell Differentiation process; Cell Lineage; Cells; Child; Chromatin; Complement; Cre-LoxP; Data; Defect; Degradation Pathway; Deposition; Development; Diagnosis; Disease; Embryo; Embryonic Development; Epigenetic Process; Equilibrium; Essential Genes; Etiology; Gene Mutation; Generations; Genes; Genetic Transcription; Genome Stability; Goals; Hematology; Hematopoiesis; Hematopoietic; Hematopoietic Neoplasms; Hematopoietic stem cells; Heritability; Histones; Human; In Vitro; Inherited; Investigation; Knockout Mice; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Molecular; Molecular Chaperones; Mus; Mutate; Mutation; Neurons; Nuclear Family; Nucleosomes; Organogenesis; Pathogenesis; Patients; Phenotype; Plant Growth Regulators; Plants; Play; Polyubiquitination; Postdoctoral Fellow; Process; Protein Isoforms; Proteins; Recycling; Repression; Research; Ribosomes; Role; Seminal; Shapes; Specific qualifier value; Stem Cell Development; System; Technology; Transcript; Transgenic Mice; United States; chromatin remodeling; de novo mutation; design; driver mutation; embryonic stem cell; epigenome; genome-wide; hematopoietic differentiation; hematopoietic stem cell differentiation; hematopoietic stem cell fate; improved; in vivo; induced pluripotent stem cell; induced pluripotent stem cell technology; insight; interest; leukemia; mouse model; multicatalytic endopeptidase complex; mutant; nucleophosmin; nucleoplasmin; preservation; programs; protein function; receptor binding; self-renewal; stem cell function; targeted treatment

NPM1 gene mutations are considered driver mutations in the pathogenesis of acute myeloid leukemia (AML). Nucleophosmin (NPM1) belongs to the nucleophosmin/nucleoplasmin (NPM) family of nuclear chaperones, of which there are three genes: NPM1, NPM2 (nucleoplasmin), and NPM3, whose protein functions include chromatin remodeling, genome stability, ribosome biogenesis, and embryogenesis. In humans, NPM1 has three isoforms of which isoform 1 is the predominant type and is the only one expressed in mouse. My postdoctoral studies focused on a fundamental epigenetic feature involving the local recycling of parental nucleosomes, which showed that repressed, but not active, chromatin domains are inherited. While attempting to identify a histone chaperone(s) that facilitates the inheritance of repressed chromatin domains in mouse embryonic stem cells (mESCs), I discovered that NPM1 plays an essential role in this process (preliminary data). While the role of NPM1 in the cell has been well characterized, its function in normal hematopoiesis remains unknown. With regard to hematopoietic stem cells (HSCs), the epigenome confers self-renewal and differentiation functions wherein inheritance of HSC chromatin states is persistent across cell cycles. In this proposal, we will identify the molecular basis of NPM1 in constructing the heritable epigenome of HSCs and determine whether aberrant function in this process contributes to the etiology of NPM1-driven cancer mutations. As species- specific differences exist between mouse and human NPM1 biology, we propose to complement human and mouse NPM1 biology utilizing in vitro human and in vivo mouse HSC differentiation systems. These systems include in vitro human induced Pluripotent Stem Cells (iPSCs) to differentiate and derive a hematopoietic progenitor cell (HPC) fate and developing an Auxin-induced degron (AID) mouse model for NPM1 to deplete NPM1 protein in vivo in a targeted and regulated manner in HSCs. Integrating human iPSC technology with an AID mouse model for NPM1 has the potential to set a precedent in assessing the function of essential genes that are frequently mutated in disease. In this instance, identifying NPM1 mediated chromatin mechanisms necessary for constructing the heritable epigenome of HSCs and its aberrant function in leukemia.

NPM1 基因突变被认为是急性髓系白血病 (AML) 发病机制中的驱动突变。 核磷蛋白 (NPM1) 属于核伴侣的核磷蛋白/核蓝蛋白 (NPM) 家族， 其中共有三个基因：NPM1、NPM2（核浆蛋白）和NPM3，其蛋白质功能包括 染色质重塑、基因组稳定性、核糖体生物发生和胚胎发生。在人类中，NPM1 三种同工型，其中同工型 1 是主要类型，并且是唯一在小鼠中表达的一种。我的 博士后研究的重点是涉及亲本的局部回收的基本表观遗传特征 核小体，表明受抑制但不活跃的染色质结构域是遗传的。在尝试的同时 鉴定促进小鼠受抑制染色质结构域遗传的组蛋白伴侣 胚胎干细胞（mESC）中，我发现NPM1在这个过程中起着至关重要的作用（初步 数据）。虽然 NPM1 在细胞中的作用已得到很好的表征，但它在正常造血中的功能 仍然未知。 对于造血干细胞（HSC），表观基因组赋予其自我更新和分化能力 其中 HSC 染色质状态的遗传在整个细胞周期中持续存在。在本提案中，我们将 确定 NPM1 在构建 HSC 可遗传表观基因组中的分子基础，并确定是否 这一过程中的异常功能导致了 NPM1 驱动的癌症突变的病因学。作为物种—— 小鼠和人类 NPM1 生物学之间存在特定差异，我们建议补充人类和 利用体外人类和体内小鼠 HSC 分化系统的小鼠 NPM1 生物学。这些系统 包括体外人类诱导多能干细胞 (iPSC)，以分化和衍生造血细胞 祖细胞 (HPC) 命运和开发生长素诱导的降解子 (AID) 小鼠模型以耗尽 NPM1 NPM1 蛋白在体内以定向和调节方式在 HSC 中进行。将人类 iPSC 技术与 NPM1 的 AID 小鼠模型有可能在评估必需基因的功能方面开创先例 在疾病中经常发生突变。在这种情况下，识别 NPM1 介导的染色质机制 构建 HSC 的可遗传表观基因组及其在白血病中的异常功能所必需的。