Uncovering the Role of the DEAD Box Helicase Ddx41 in Hematopoiesis

揭示 DEAD Box 解旋酶 Ddx41 在造血中的作用

基本信息

批准号：
10212445
负责人：
Joshua Weinreb
金额：
$ 5.1万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-16 至 2022-07-15
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10212445
关键词：
AML/MDS Acute Myelocytic Leukemia Address Affect Anemia Animal Model Blood Blood Cells Cell Line Cells Clinical Co-Immunoprecipitations Complex Data Defect Development Developmental Biology Disease Dysmyelopoietic Syndromes Elderly Embryo Erythropoiesis Event Functional disorder Genes Genetic Germ-Line Mutation Goals Hematologic Neoplasms Hematological Disease Hematology Hematopoiesis Hematopoietic Hematopoietic System Hematopoietic stem cells High-Throughput Nucleotide Sequencing In Situ Hybridization Lead Mediating Messenger RNA Modeling Molecular Molecular Biology Techniques Mutate Mutation Myelopoiesis Neutropenia Outcome Pancytopenia Pathogenesis Pathway interactions Patients Phenotype Population Process Proteins RNA Splicing Regulation Role Sampling Somatic Mutation Spliceosomes Stains Structure Techniques Testing Training Transgenic Organisms Work Zebrafish advanced disease bone marrow failure syndrome cell growth cell type cytopenia experimental study helicase in vivo in vivo Model insight knock-down leukemogenesis loss of function mutant neoplastic cell novel novel therapeutic intervention premalignant

项目摘要

Abstract Myelodysplastic syndromes (MDS), a group of pre-malignant bone marrow failure syndromes arising from defects in hematopoietic stem cells (HSCs), are amongst the most common hematological malignancies of the elderly with ~30% progressing to acute myeloid leukemia (AML). Recently, loss-of-function germline and somatic mutations in the DEAD-box Helicase 41 gene (DDX41) have been identified in patients with MDS and AML, and are thought to contribute to disease pathogenesis. Both germline and somatic DDX41 mutations are thought to promote hematopoietic deregulation and leukemogenesis. Although a strong clinical correlation is found between mutations in DDX41 and MDS, the in vivo role of DDX41 in hematopoiesis has not been elucidated. To address this question, we will characterize hematopoiesis in a zebrafish ddx41 loss-of-function mutant. Our preliminary studies indicate that ddx41 mutants develop neutropenia and anemia. This animal model will allow us to elucidate the in vivo role of Ddx41 in normal hematopoiesis and the underlying mechanism for any defects. DDX41 has been implicated in splicing and shown to associate with components of the spliceosome including Splicing Factor 3B, subunit 1 (SF3B1), the most commonly mutated splicing factor in MDS. Additionally, MDS/AML patient samples with DDX41 mutations displayed errors in mRNA splicing that typically occur when components of the spliceosome are defective. Although these data point towards a role for DDX41 in splicing, it is still unknown if splicing aberrations contribute to the observed abnormalities in DDX41-mutated hematologic diseases. Using ddx41-deficient zebrafish will permit us to delineate the functionally relevant early molecular events leading to blood cell defects when ddx41 is mutated, which is anticipated to provide novel insight into the origins of MDS. In this proposal, we will use our novel in vivo model of Ddx41-deficiency to test the hypothesis that Ddx41 is critical for normal hematopoiesis via regulation of splicing, and that malfunctioning of this process contributes to the hematological defects seen in DDX41- mutated MDS/AML. In Aim 1, we will determine which blood populations require Ddx41 and which functional domains of Ddx41 are required for healthy hematopoiesis. In Aim 2, we will elucidate connections between DDX41 and SF3B1 using protein and genetic interaction studies. Combined these studies will reveal insights into the pathophysiology of DDX41-mutated MDS/AML.

抽象的骨髓增生异常综合征 (MDS)，一组由以下原因引起的癌前骨髓衰竭综合征造血干细胞（HSC）缺陷是最常见的血液恶性肿瘤之一约 30% 的老年人进展为急性髓系白血病 (AML)。最近，功能丧失的种系和已在 MDS 患者中发现 DEAD-box 解旋酶 41 基因 (DDX41) 的体细胞突变 AML，被认为与疾病发病机制有关。种系和体细胞 DDX41 突变均被认为可促进造血失调和白血病发生。尽管有很强的临床相关性在 DDX41 和 MDS 突变之间发现，DDX41 在造血中的体内作用尚未明确阐明了。为了解决这个问题，我们将描述斑马鱼 ddx41 功能丧失的造血作用突变体。我们的初步研究表明 ddx41 突变体会出现中性粒细胞减少症和贫血症。这种动物该模型将使我们能够阐明 Ddx41 在正常造血过程中的体内作用及其潜在作用任何缺陷的机制。 DDX41 与拼接有关并被证明与组件相关剪接体，包括剪接因子 3B，亚基 1 (SF3B1)，最常见的突变剪接因子在MDS中。此外，具有 DDX41 突变的 MDS/AML 患者样本显示 mRNA 剪接错误，当剪接体的成分有缺陷时通常会发生。尽管这些数据表明了一个角色对于剪接中的 DDX41，目前尚不清楚剪接畸变是否会导致观察到的异常 DDX41 突变的血液系统疾病。使用 ddx41 缺陷斑马鱼将使我们能够描绘当 ddx41 突变时，功能相关的早期分子事件会导致血细胞缺陷，即预计将为 MDS 的起源提供新的见解。在这个提案中，我们将使用我们的体内小说 Ddx41 缺陷模型，用于检验 Ddx41 通过调节对正常造血至关重要的假设剪接过程的故障导致了 DDX41-中所见的血液学缺陷突变的 MDS/AML。在目标 1 中，我们将确定哪些血型需要 Ddx41，以及哪些功能性血型需要 Ddx41。 Ddx41 结构域是健康造血所必需的。在目标 2 中，我们将阐明之间的联系 DDX41 和 SF3B1 使用蛋白质和遗传相互作用研究。综合这些研究将揭示见解 DDX41 突变的 MDS/AML 的病理生理学。