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) 的维持和功能至关重要。影响核糖体生物合成的核糖体蛋白或基因突变会导致“核糖体病”，这是一类骨髓衰竭 (BMF) 综合征如舒瓦赫曼-戴蒙德综合征 (SDS) 所示，是一种 BMF 疾病伴有进行性造血干细胞和祖细胞 (HSPC) 衰竭并易发生骨髓恶性肿瘤是由装配因子中的种系双等位基因突变驱动的，这些因子对于 60S 核糖体亚基的成熟然而，HSC 中核糖体组装的调控方式仍然很差。重要的是，除了同种异体干细胞之外，它对造血功能障碍也有贡献。移植，减轻 BMF 中 HSPC 缺陷的治疗干预措施不存在。基于我们的新研究发现了 E3 泛素连接酶 HectD1 在调节 HSC 中的新作用 Hectd1缺陷的HSC在移植能力和功能方面表现出显着的缺陷。自我更新，伴随着整体蛋白质合成的减少 HSC 的机制。 Hectd1 缺陷导致的功能障碍与泛素化和核糖体组装异常直接相关。调节 ZNF622 的稳定性，ZNF622 是 60S 大核糖体成熟的关键生物发生因子细胞质中的 HectD1 亚基的消耗导致 ZNF622 和抗关联因子的积累。 60S 亚基上的 eIF6，降低了 80S 单体与 60S 的比率，与亚基连接缺陷一致重要的是，Hectd1 缺陷细胞中 ZNF622 的敲除可恢复蛋白质。合成和 HSC 重建能力这一发现代表了基因抑制的罕见体内例子。与功能失调的核糖体生物发生相关的 HSC 缺陷的研究，这一新途径对 HSC 失败的病因学和“核糖体病”的临床治疗，要求详细的机制在此，我们对HectD1和ZNF622在其中的作用进行全面深入的分析。核糖体生物发生和 HSC 在目标 1 中，我们建议研究 HectD1 和 ZNF622 在 HSC 中的作用。以及它们如何结合互补遗传学、基因组学和其他方法相互作用来调节 HSC 功能在目标 2 中，我们将系统分析 HectD1/ZNF622 是否影响不同方面。此外，我们将进行定量蛋白质组学来评估核糖体水平或核糖体组成受 Hectd1/ZNF622 丢失的影响在目标 3 中，我们将探讨 Hectd1/ZNF622 的潜在失调。 HECTD1 和 ZNF622 在人类 BMF 综合征中的作用，并探索靶向 ZNF622 的治疗潜力我们的研究揭示了核糖体生物发生功能障碍对 BMF 的治疗作用。泛素化通过控制失调的核糖体生物发生因子来调节 HSC 功能我们的发现可能会对调节的治疗潜力产生重大影响。泛素化和/或核糖体生物发生因素在 BMF 综合征中恢复 HSC 功能。