Regulation of Ribosome Biogenesis in Hematopoietic Stem Cells

造血干细胞核糖体生物合成的调控

基本信息

批准号：
10265594
负责人：
Wei Tong
金额：
$ 60.24万
依托单位：
CHILDREN'S HOSP OF PHILADELPHIA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-18 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10265594
关键词：
Affect Allogenic Biochemical Biogenesis Biological Blood Blood Cells Bone Marrow Bone Marrow Transplantation Cell Line Cell Maintenance Cell physiology Cells Clinical Clinical Treatment Collaborations Cytoplasm Data Defect Disease Equilibrium Etiology Exhibits Failure Functional disorder Gene Proteins Genes Genetic Genetic Suppression Genomics Goals Growth Hematopoiesis Hematopoietic Hematopoietic stem cells Human Knockout Mice Link Malignant Neoplasms Marrow Mediating Mutation Myeloproliferative disease Pancytopenia Pathway interactions Patients Polyribosomes Population Predisposition Prokaryotic Cells Protein Biosynthesis Proteins Proteomics Registries Regulation Research Ribosomal Proteins Ribosomes Role Shwachman-Diamond syndrome Signal Transduction Stem cell transplant Structure Syndrome Testing Therapeutic Therapeutic Intervention Translation Process Protein Translations Transplantation Ubiquitin Ubiquitination Validation Yeasts base bone marrow failure syndrome cancer predisposition cell growth conditional knockout epigenomics exome sequencing genetic analysis in vivo insight interest knock-down novel novel therapeutic intervention novel therapeutics polypeptide prevent programs reconstitution ribosome profiling self-renewal small hairpin RNA stem cell function stem cells transcriptome transcriptome sequencing treatment strategy ubiquitin-protein ligase

项目摘要

Abstract Tightly-regulated protein synthesis rates are critical for hematopoietic stem cell (HSC) maintenance and function. Mutations in ribosome proteins or genes that affect ribosome biogenesis cause “ribosomopathies”, a class of bone marrow failure (BMF) syndromes. As prominently illustrated by Shwachman-Diamond Syndrome (SDS), a BMF disease with progressive hematopoietic stem and progenitor cell (HSPC) failure and predisposition to myeloid malignancies, is driven by germline biallelic mutations in the assembly factors essential for the maturation of the 60S ribosome subunit. However, how ribosome assembly is regulated in HSCs remains poorly understood, as is its contribution to hematopoietic dysfunction. Importantly, other than allogeneic stem cell transplantation, therapeutic interventions that mitigate the HSPC defects in BMF do not exist. This application is based on our new studies that uncovered a novel role for the E3 ubiquitin ligase, HectD1, in regulating HSC function via ribosome biogenesis. Hectd1-deficient HSCs exhibit a striking defect in transplantation ability and self-renewal, concomitant with a reduction in global protein synthesis. The mechanism underlying HSC dysfunction upon Hectd1 deficiency is directly linked to aberrant ribosome assembly by ubiquitinating and regulating the stability of ZNF622, a critical biogenesis factor for the maturation of the 60S large ribosomal subunit in the cytoplasm. Depletion of HectD1 led to an accumulation of ZNF622 and the anti-association factor eIF6 on the 60S subunit, decreased 80S monosome to 60S ratio, consistent with a subunit joining defect associated with SDS-like diseases. Importantly, knockdown of ZNF622 in Hectd1-deficient cells restored protein synthesis and HSC reconstitution capacity. This finding represents a rare in vivo example of genetic suppression of HSC defects associated with dysfunctional ribosome biogenesis. The implications of this novel pathway to the etiology of HSC failure and clinical treatment of “ribosomopathies”, mandates detailed mechanistic understanding. Here, we propose comprehensive and in-depth analyses on the role of HectD1 and ZNF622 in ribosome biogenesis and HSCs. In aim 1, we propose to investigate the roles of HectD1 and ZNF622 in HSCs and how they interact to regulate HSC function, using a combination of complementary genetics, genomics, and biochemical approaches. In aim 2, we will systematically analyze if HectD1/ZNF622 affects different aspects of protein translation controls. Moreover, we will perform quantitative proteomics to assess if ribosome levels or ribosome composition is affected by Hectd1/ZNF622 loss. In aim 3, we will interrogate potential dysregulation of HECTD1 and ZNF622 in human BMF syndromes and explore therapeutic potential of targeting ZNF622 for the treatment of BMF with dysfunctional ribosome biogenesis. Our study implicates a previously unappreciated role of ubiquitination in regulating HSC function via controlling ribosome biogenesis factors, which are dysregulated in ribosomopathies. Our findings will likely have significant impact on the therapeutic potential of modulating ubiquitination and/or ribosome biogenesis factors in restoring HSC functions in BMF syndromes.

抽象的严格调节的蛋白质合成速率对于造血干细胞（HSC）维持和功能至关重要。核糖体蛋白或影响核糖体生物发生的基因的突变引起的“核糖体病”，一类骨髓衰竭（BMF）综合征。正如Shwachman-Diamond综合征（SDS）明显地说明的那样 BMF疾病患有进行性造血干和祖细胞（HSPC）失败和易感性的疾病髓样恶性肿是由组装因子中的种系双质突变驱动的 60年代核糖体亚基的成熟。但是，如何在HSC中调节核糖体组件保持较差了解，它对造血功能障碍的贡献也是如此。重要的是，除了同种异体干细胞不存在减轻BMF中HSPC缺陷的移植，治疗干预措施。此应用程序是基于我们的新研究，该研究发现了E3泛素连接酶的新作用Hectd1，在调节HSC中通过核糖体生物发生功能。 HSC缺乏HSC在移植能力和自我更新，伴随着全球蛋白质合成的减少。 HSC的基础机制 hectd1缺乏症功能障碍通过泛素化和调节ZnF622的稳定性，这是60年代成熟的关键生物发生因子细胞质中的亚基。 hectd1的耗竭导致Znf622的积累和抗关联因子的积累 60年代亚基的EIF6，降低了80年代的单体组与60s的比率，与亚基连接缺陷一致与SDS样疾病有关。重要的是，hectd1缺陷型细胞中ZnF622的敲低恢复了蛋白质合成和HSC重建能力。这一发现代表了遗传抑制的罕见的体内例子与功能失调的核糖体生物发生相关的HSC缺陷。这种新颖途径的含义 HSC衰竭和“核糖体病”的临床治疗的病因，要求详细的机理理解。在这里，我们提出了有关Hectd1和Znf622在的作用的全面和深入分析核糖体生物发生和HSC。在AIM 1中，我们建议研究HSC在HSC中HECTD1和ZnF622的作用以及它们如何使用互补遗传学，基因组学和生化方法。在AIM 2中，我们将系统地分析Hectd1/Znf622是否影响蛋白质翻译控制。此外，我们将执行定量蛋白质组学来评估核糖体水平或核糖体成分受HECTD1/ZNF622损失的影响。在AIM 3中，我们将询问潜在的失调人BMF综合征中的hectd1和Znf622，并探索针对Znf622的治疗潜力用功能失调的核糖体生物发生处理BMF。我们的研究实施了先前未欣赏的角色通过控制核糖体生物发生因子来调节HSC功能的泛素化因子失调在核糖体病中。我们的发现可能会对调节的治疗潜力产生重大影响在恢复BMF综合征中HSC功能的泛素化和/或核糖体生物发生因子。