Investigating DDX3X as a sex-specific translational regulator associated with intellectual disability

研究 DDX3X 作为与智力障碍相关的性别特异性翻译调节因子

基本信息

批准号：
10018061
负责人：
Silvia De Rubeis
金额：
$ 21.19万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-15 至 2021-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10018061
关键词：
Accounting Address Affect Affinity Chromatography Behavioral Biochemical Biochemistry Biology Brain Caring Clinical Complex Data Defect Dendritic Spines Development Diagnosis Disease Embryo Family Female Fragile X Syndrome Functional disorder Gene Dosage Genes Genetic Genetic Structures Genetic Translation Goals Health Impairment Individual Inherited Intellectual functioning disability Interdisciplinary Study Intervention Knowledge Light Maps Mediating Medical Genetics Messenger RNA Methods Mission Modeling Molecular Biology Molecular Target Mothers Mus Mutation National Institute of Child Health and Human Development Neurobiology Neurodevelopmental Disorder Neurons Neurosciences Pathogenicity Patients Pharmacological Treatment Pharmacology Phenotype Precision therapeutics Predisposition Prevalence Prevention Problem behavior Process Proteome Public Health RNA Helicase Regulation Reporting Research Ribosomes Role Severities Sex Bias Sex Differences Specificity Structural Models Structure Synapses Syndrome Testing Translating Translation Initiation Translational Regulation Translations Vertebral column Viral X Chromosome X Inactivation X-linked intellectual disability autism spectrum disorder base biochemical model comorbidity de novo mutation dosage high risk improved innovation male mouse model mutant neglect new therapeutic target novel pre-clinical precision medicine recruit response risk variant sex small molecule inhibitor structural biology synaptogenesis therapeutic target transcriptome sequencing

项目摘要

PROJECT SUMMARY There are fundamental gaps in our understanding of the genetics and neurobiology of DDX3X, a high-risk gene for X-linked intellectual disability (ID) accounting for up to 2% of unexplained diagnoses in females. DDX3X mutations display a puzzling sexual dichotomy: most mutations are de novo and found only in females; the few mutations in males are inherited from healthy mothers. DDX3X regulates mRNA translation, but the mechanisms of action in neurons, the target genes, and the impact of clinical mutations have not been studied. Also, the influence of sex remains unknown. There is a critical need to fill these gaps because, until we do so, implementing strategies that use DDX3X as a therapeutic target remains out of reach. The long-term goal is to map the synaptic mechanisms underlying ID and identify new therapeutic targets. The overall objective is to capture the sex-specific synaptic changes resulting from mutations in DDX3X. The central hypothesis is that DDX3X regulates synaptic translation and synaptogenesis in a sex-specific manner: mutations impact these processes differently in males and females, leading to sex biases in prevalence and severity of the condition. The rationale is that, once we know how DDX3X regulates synaptic translation and how sex influences it, mechanism-based precision therapeutics can be developed. The central hypothesis will be tested by pursuing two Specific Aims: 1) Analyze the role of DDX3X in synaptic translation and synaptogenesis; and, 2) Determine the effects of sex-specific DDX3X mutations. Under Aim 1, biochemical and structural methods will be applied to study DDX3X-mediated translation in mouse synapses. Viral-based Translating Ribosome Affinity Purification (vTRAP-seq) will be used to map the mRNAs regulated by DDX3X in male and female mouse synapses. Dendritic spines analyses in male and female single-embryo neurons from a novel DDX3X mouse model will be used to assess the role in synaptogenesis. Under Aim 2, two male- and three female-pathogenic mutations will be structurally and biochemically modeled. The mutations will be introduced in cultured neurons and the spine phenotype compared across mutations and sexes to understand why female-pathogenic mutations are more severe. All these methods are part of the applicant's expertise. This proposal is innovative because it addresses the biology of a novel ID high-risk gene in light of a central and yet overlooked aspect: sex. It is innovative because it models patient-specific mutations in neurons. It is also innovative because it integrates genetics, structural biology, biochemistry, molecular biology and neuroscience, and uses a novel mouse model and novel DDX3X small-molecule inhibitors. This application is significant because it will critically advance our understanding of DDX3X syndrome and ID more broadly. The results will expose fundamental aspects of synaptogenesis, thus advancing the knowledge of brain development in health and disease. The results are expected to have a positive impact because they will pinpoint novel molecular targets for precision medicine, while informing clinical genetics care, with both short-term and long-term benefits for families.

项目摘要我们对DDX3X（一种高风险基因的遗传学和神经生物学）的理解有根本的差距对于X连锁的智力残疾（ID），占女性无法解释的诊断的2％。 ddx3x 突变表现出令人困惑的性二分法：大多数突变是从头开始的，仅在女性中发现。少数男性的突变是从健康的母亲那里继承的。 DDX3X调节mRNA翻译，但尚未研究神经元，靶基因和临床突变影响的作用机理。而且，性的影响仍然未知。填补这些空白的迫切需要，因为在我们这样做之前，实施将DDX3X用作治疗靶标的策略尚无范围。长期目标是绘制ID基础的突触机制并确定新的治疗靶标。总体目标是捕获DDX3X突变引起的性别特异性突触变化。中心假设是 DDX3X以性别特异性调节突触翻译和突触发生：突变影响这些在男性和女性中的过程有所不同，导致病情患病率和严重程度的性偏见。理由是，一旦我们知道DDX3X如何调节突触翻译以及性别如何影响其，可以开发基于机制的精度治疗剂。中心假设将通过追求来检验两个具体的目的：1）分析DDX3X在突触翻译和突触发生中的作用；以及，2）确定性别特异性DDX3X突变的影响。在AIM 1下，将采用生化和结构方法研究小鼠突触中的DDX3X介导的翻译。基于病毒的翻译核糖体亲和力纯化（vtrap-seq）将用于绘制雄性和雌性小鼠在ddx3x中调节的mRNA 突触。新型DDX3X小鼠的男性和雌性单胚神经元中的树突状刺分析模型将用于评估突触发生中的作用。在AIM 2下，两个雄性和三个女性生病突变将在结构和生化建模。突变将引入培养的神经元中以及跨突变和性别的脊柱表型，以了解为什么女性生病突变更为严重。所有这些方法都是申请人专业知识的一部分。该建议是创新的因为它鉴于中心而忽略的方面，它解决了一种新颖的ID高风险基因的生物学：性别。它具有创新性，因为它模拟了神经元中患者特异性突变。这也是创新的，因为它整合遗传学，结构生物学，生物化学，分子生物学和神经科学，并使用一种新颖的小鼠模型和新型DDX3X小分子抑制剂。该应用程序很重要，因为它将至关重要提高我们对DDX3X综合征和ID的了解。结果将暴露基本突触发生的各个方面，从而促进了健康和疾病中大脑发育的知识。这预计结果将产生积极的影响，因为它们将确定新的分子靶标的精度医学在为临床遗传学护理提供信息的同时，对家庭具有短期和长期益处。