Cellular and molecular determinants of DDX3X syndrome

DDX3X 综合征的细胞和分子决定因素

• 批准号: 10790037
• 负责人: Silvia De Rubeis
• 金额: $ 42.25万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10790037
• 关键词: Ablation; Accounting; Address; Adult; Affect; Affinity Chromatography; Behavior; Behavioral; Biochemistry; Brain; Cell model; Cell physiology; Cognitive; Cognitive deficits; Defect; Development; Developmental Biology; Electroporation; Female; Functional disorder; Genes; Genetic; Genetic Diseases; Goals; Individual; Intellectual functioning disability; Interdisciplinary Study; Laboratories; Link; Maps; Measures; Methods; Mission; Molecular; Motor; Mus; Mutant Strains Mice; Mutation; National Institute of Child Health and Human Development; Neurobiology; Neurons; Neurosciences; Phenotype; Prevention; Process; Prosencephalon; Public Health; Research; Ribosomes; Social Behavior; Standardization; Syndrome; Testing; Therapeutic; Translating; Validation; Viral; behavioral outcome; improved; in utero; in vivo; innovation; mRNA Translation; motor behavior; motor deficit; mouse model; nerve stem cell; neurogenesis; novel therapeutic intervention; social; social deficits; targeted treatment; therapeutically effective

PROJECT SUMMARY There are fundamental gaps in our understanding of DDX3X syndrome, a genetic condition accounting for up to 2% of intellectual disability (ID) in females and caused by mutations in the X-linked gene DDX3X. Most affected individuals are females with DDX3X haploinsufficiency. A recent study using cell models and in utero manipulations in mouse has shown that Ddx3x regulates cortical neurogenesis and mRNA translation in neuronal progenitors. Yet, the lack of a mouse model with construct validity for DDX3X syndrome has impeded to faithfully capture the molecular and cellular determinants of the cognitive, social and motor deficits observed in individuals with DDX3X syndrome. There is a critical need to fill these gaps because, until we do so, understanding DDX3X syndrome and developing effective therapeutics remain out of reach. To address this unmet need, a mouse modeling DDX3X haploinsufficiency (Ddx3x+/-) was generated in our laboratory. The long-term goal is to unravel the pathophysiology of ID and identify targets for therapeutics. The overall objective is to capture the molecular and cellular mechanisms underlying DDX3X syndrome. The central hypothesis is that Ddx3x dictates the formation of cortical projection neurons subserving cognitive, social, and motor functions, and does so by regulating mRNA translation in the developing cortex. The rationale is that, once we identify the mechanisms of DDX3X syndrome and reliable phenotypes in the mouse model, therapeutics can be developed and tested. The hypothesis will be tested by pursuing three Specific Aims: 1) Assess the neurodevelopmental defects in a mouse model of DDX3X syndrome; 2) Capture the molecular defects in a mouse model of DDX3X syndrome; and, 3) Correlate cellular function to behavioral outcomes in Ddx3x mutant mice. Under Aim 1, the developmental and adult cognitive, social, and motor behavior of Ddx3x+/- mice will be measured with a standardized behavioral battery. Cortical projection neurons will be studied in Ddx3x+/- mice by combining cellular and in vivo (e.g., in utero electroporation) approaches. Under Aim 2, Ddx3x targets in projection neurons will be mapped using the translating ribosome affinity purification (TRAP) method for discovery and its viral-based development (vTRAP) for independent validation. Under Aim 3, conditional Ddx3x mice with the gene ablated in the forebrain or in specific cortical layers will be tested for development and adult behavior. The proposal is innovative because it addresses the neurobiology of a largely unknown ID gene and characterizes the first mouse model of DDX3X syndrome. It is also innovative because it bridges genetics, biochemistry, molecular and cellular neuroscience, developmental biology, and behavioral neuroscience. The application is significant because it will advance our understanding of ID pathophysiology, while shedding new light on corticogenesis, a fundamental process for brain functioning. These results are expected to have a positive impact because they will pave the way for novel therapeutic interventions for ID.

项目总结 我们对DDX3X综合征的理解存在根本差距，这是一种导致UP的遗传病 女性智力残疾(ID)的2%是由X连锁基因DDX3X突变引起的。多数 受影响的个体是患有DDX3X单倍体功能不全的女性。最近一项使用细胞模型和子宫内的研究 在小鼠的操作表明，DDX3X调节大脑皮质神经发生和mRNA翻译。 神经前体细胞。然而，缺乏对DDX3X综合征具有结构效度的小鼠模型已成为障碍 忠实地捕捉到认知、社交和运动缺陷的分子和细胞决定因素 在患有DDX3X综合征的个体中。迫切需要填补这些空白，因为在我们这样做之前， 了解DDX3X综合征和开发有效的治疗方法仍然遥不可及。要解决这个问题 为了满足需求，我们实验室培育了一只模拟DDX3X单倍体功能不全(DDX3X+/-)的小鼠。这个 长期目标是解开ID的病理生理学机制，并确定治疗的靶点。整体而言 目的：了解DDX3X综合征的分子和细胞机制。中环 假说是，DDX3X决定了大脑皮质投射神经元的形成，这些神经元从属于认知、社交和 运动功能，并通过调节发育中的皮质中的mRNA翻译来实现这一功能。理由是， 一旦我们确定了DDX3X综合征的机制和小鼠模型中可靠的表型， 治疗学可以被开发和测试。这一假设将通过追求三个具体目标来检验：1) 评估DDX3X综合征小鼠模型的神经发育缺陷；2)捕获分子 DDX3X综合征小鼠模型的缺陷；以及，3)细胞功能与行为结果之间的相关性 DDX3X突变小鼠。在目标1下，儿童的发育和成人认知、社会和运动行为 将使用标准化的行为电池对DDX3X+/-小鼠进行测量。大脑皮层投射神经元 通过结合细胞和体内(例如，宫内电穿孔)方法在DDX3X+/-小鼠身上进行研究。在……下面 目的2，利用翻译核糖体亲和纯化技术定位投射神经元中的DDX3X靶点 (陷阱)发现方法及其基于病毒的开发(VTRAP)用于独立验证。在AIM下 3，在前脑或特定皮质层中有条件的DDX3X基因被去除的小鼠将被测试 发展和成人行为。这项提议是创新的，因为它解决了在很大程度上 未知的ID基因，这是第一个DDX3X综合征小鼠模型的特征。它还具有创新性，因为它 连接遗传学、生物化学、分子和细胞神经科学、发育生物学和行为学 神经科学。这一应用具有重要意义，因为它将促进我们对ID病理生理学的理解， 同时为大脑功能的基本过程--皮质生成提供了新的线索。这些结果是 预计将产生积极影响，因为它们将为ID的新治疗干预铺平道路。

项目成果

Developmental and Behavioral Phenotypes in a Mouse Model of DDX3X Syndrome.

• DOI: 10.1016/j.biopsych.2021.05.027
• 发表时间: 2021-12-01
• 期刊: Biological psychiatry
• 影响因子: 10.6
• 作者: Boitnott A;Garcia-Forn M;Ung DC;Niblo K;Mendonca D;Park Y;Flores M;Maxwell S;Ellegood J;Qiu LR;Grice DE;Lerch JP;Rasin MR;Buxbaum JD;Drapeau E;De Rubeis S
• 通讯作者: De Rubeis S