The role of Rpl5 haploinsufficiency in hematopoietic stem/progenitor cell function in Diamond Blackfan anemia

Rpl5 单倍体不足在 Diamond Blackfan 贫血造血干/祖细胞功能中的作用

• 批准号: 10578722
• 负责人: Sharon A Singh
• 金额: $ 16.96万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10578722
• 关键词: Affect; Age; Age Months; Anemia; Animal Model; Aplastic Anemia; Basic Science; Biological Assay; Birth; Blood Transfusion; Bone Marrow; CFU-E; Cell Count; Cell Culture Techniques; Cell Cycle; Cell Cycle Regulation; Cells; Cellular Stress; Cellular biology; Characteristics; Child; Childhood; Chronic; Clinical; Collaborations; Complex; Data; Defect; Development; Diamond-Blackfan anemia; Disease; Disease remission; Dysmyelopoietic Syndromes; Education; Embryo; Environment; Erythrocytes; Erythropoiesis; Etiology; Evaluation; Failure; Functional disorder; Funding; GATA1 gene; Gene Proteins; Genetic; Genetic Transcription; Germ-Line Mutation; Goals; Health; Hematopoiesis; Hematopoietic stem cells; Heme; Hemoglobin; Heterozygote; Human; Hydrops Fetalis; In Vitro; Inbred Mouse; Individual; Inherited; Innate Immune System; Junior Physician; Laboratory Research; Longevity; Macrocytic Anemia; Mediator; Mentors; Mentorship; Michigan; Modeling; Mus; Mutant Strains Mice; Mutation; Neonatal; Newborn Infant; Normal Cell; Pathogenesis; Pathway interactions; Patients; Pediatric Hematologist; Pediatric Hematology; Pediatric Oncologist; Penetrance; Persons; Phenotype; Physicians; Play; Pronormoblasts; Protein Biosynthesis; Protein Deficiency; Proteins; Reactive Oxygen Species; Research; Resolution; Resources; Ribosomal Proteins; Ribosomes; Role; Scientist; Severities; Spontaneous Remission; Stress; Testing; Toxic effect; Training; Transfusion; Translations; Transplantation; Universities; Work; bone marrow failure syndrome; burden of illness; career; critical developmental period; critical period; design; erythroid differentiation; exhaustion; experimental study; hematopoietic cell transplantation; immune activation; improved; in utero; in vivo; mortality; mouse model; mutant; novel; novel therapeutics; patient registry; prevent; stem; stem cell biology; stem cell function; stem cells

PROJECT SUMMARY/ABSTRACT Anemia is an extraordinarily common condition that affects approximately 1 in 3 people around the globe. Erythropoiesis is exquisitely sensitive to both endogenous and exogenous stress, which contributes to this massive global disease burden. Genetic defects in ribosomes that lead to severe anemia are associated with rare inherited bone marrow failure syndromes as well as more commonly acquired myelodysplastic syndrome. The pathway from ribosomal protein haploinsufficiency to defective erythropoiesis in Diamond Blackfan anemia (DBA) is complex and likely involves multiple factors (e.g. diminished GATA1 translation, heme toxicity and/or nucleolar stress). Patients with DBA can undergo spontaneous remission such that chronic transfusions are not required. This phenomenon is poorly understood using current patient registries and animal models. Understanding normal pathways that lead to the resolution or improvement of anemia is critical in order to advance therapies for DBA and other causes of anemia. The applicant is a pediatric hematologist/oncologist who actively treats patients with all types of genetic and acquired anemias and her long term goal is to become a physician-scientist with expertise in hematopoiesis. To achieve this goal, the candidate has proposed the following training plan: 1) To develop expertise in isolation and analysis of hematopoietic stem/progenitor cells; 2) To further develop expertise employing mouse models and human hematopoietic stem cell culture to study disease-specific mechanisms; 3) To develop an independently funded basic research laboratory; 4) To develop into a successful physician-scientist focused on mentorship and collaboration. The candidate has assembled a mentorship team with expertise in hematopoiesis and mouse models (Drs. Engel and Li). The environment at the University of Michigan is highly conducive to the training of successful junior physician-scientists with exceptional resources, educational and collaborative opportunities. The scientific proposal centers on the hypothesis that DBA remission, even in these inbred mice, is based on a threshold effect on hematopoietic stem/progenitor cells that responds to both exogenous and endogenous modifiers. The rationale for this hypothesis is based on observations in our unique DBA mouse model where all neonatal Rpl5 (ribosomal protein gene) mutant mice are born with anemia, which contributes to early mortality in some mice while others survive and maintain normal hemoglobin characteristics throughout their lifespan. Aim 1 will determine if there is an intrinsic defect in stem/progenitor cells and/or the bone marrow microenvironment in mutant mice by examining transplantation of hematopoietic cells from different developmental periods. Aim 2 will test whether cellular stress alters the niche and/or hematopoietic stem/progenitor cell function. Aim 3 will examine whether cell cycle dysregulation is responsible for defective hematopoiesis during developmentally vulnerable periods or during cellular stress. Completion of training under the guidance of senior mentors will enable the applicant to develop into an independent physician-scientist with greater expertise in hematopoiesis.

项目概要/摘要 贫血是一种非常常见的疾病，影响全球大约三分之一的人。 红细胞生成对内源性和外源性应激都非常敏感，这导致了这种情况 巨大的全球疾病负担。导致严重贫血的核糖体遗传缺陷与 罕见的遗传性骨髓衰竭综合征以及更常见的获得性骨髓增生异常综合征。 钻石黑扇贫血症中从核糖体蛋白单倍体不足到红细胞生成缺陷的途径 (DBA) 很复杂，可能涉及多种因素（例如 GATA1 翻译减弱、血红素毒性和/或 核仁应激）。 DBA 患者可以自发缓解，因此可以长期输血 不需要。目前的患者登记和动物模型对这种现象知之甚少。 了解导致贫血消退或改善的正常途径对于以下方面至关重要： 针对 DBA 和其他贫血原因的先进疗法。申请人是儿科血液学家/肿瘤学家 她积极治疗各种类型的遗传性和获得性贫血患者，她的长期目标是成为 具有造血学专业知识的医师科学家。为了实现这一目标，候选人提出了 以下培训计划： 1) 培养造血干/祖细胞分离和分析方面的专业知识； 2) 进一步发展利用小鼠模型和人类造血干细胞培养进行研究的专业知识 疾病特异性机制； 3）建立独立资助的基础研究实验室； 4）开发 成为一名专注于指导和合作的成功的医生科学家。候选人已经组建了一个 具有造血和小鼠模型专业知识的导师团队（Engel 博士和 Li 博士）。环境位于 密歇根大学非常有利于培养成功的初级医师科学家 卓越的资源、教育和合作机会。科学建议的核心是 假设 DBA 缓解，即使是在这些近交系小鼠中，也是基于对造血功能的阈值效应 对外源性和内源性调节剂都有反应的干/祖细胞。这样做的理由 假设基于我们独特的 DBA 小鼠模型的观察，其中所有新生儿 Rpl5（核糖体 蛋白质基因）突变小鼠出生时患有贫血，这导致一些小鼠过早死亡，而另一些小鼠则导致早期死亡 在其整个生命周期中存活并保持正常的血红蛋白特征。目标 1 将确定是否存在 是突变小鼠干/祖细胞和/或骨髓微环境的内在缺陷 检查不同发育时期的造血细胞的移植。目标 2 将测试是否 细胞应激改变生态位和/或造血干/祖细胞功能。目标 3 将检查是否 细胞周期失调是发育脆弱期造血缺陷的原因 或在细胞应激期间。在资深导师的指导下完成培训将使申请人能够 发展成为一名独立的医师科学家，在造血方面拥有更丰富的专业知识。