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样白血病（AML）的发病机理中的驱动突变。 核素（NPM1）属于核伴侣蛋白/核纤维素（NPM）核伴侣， 其中有三个基因：NPM1，NPM2（核纤维蛋白）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有 其三种同工型是主要类型，是小鼠中唯一表达的类型。我的 博士后研究的重点是涉及父母局部回收的基本表观遗传特征 核小组表明，该核小体被抑制但不是活性的染色质结构域是遗传的。尝试 识别组蛋白伴侣，以促进小鼠中抑制染色质结构域的遗传 胚胎干细胞（MESC），我发现NPM1在此过程中起着至关重要的作用（初步 数据）。虽然NPM1在细胞中的作用已经很好地表征，但其在正常造血中的功能 仍然未知。 关于造血干细胞（HSC），表观基因组赋予自我更新和分化 HSC染色质状态的遗传性在细胞周期中持续存在的功能。在此提案中，我们将 确定NPM1的分子基础在构建HSC的可遗传表观基因组时，并确定是否是否 在此过程中的异常功能有助于NPM1驱动的癌症突变的病因。作为物种 - 小鼠和人类NPM1生物学之间存在具体差异，我们建议补充人类和 小鼠NPM1生物学利用体外人体和体内小鼠HSC分化系统。这些系统 包括体外人类诱导的多能干细胞（IPSC），以区分和得出造血 祖细胞（HPC）命运并开发出生长素诱导的Degron（AID）小鼠模型，以耗尽NPM1 NPM1蛋白在HSC中以靶向和调节方式进行体内。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设定先例 经常在疾病中突变。在这种情况下，识别NPM1介导的染色质机制 构建HSC的遗传表观及其在白血病中的异常功能所必需的。