Cellular and molecular determinants of DDX3X syndrome

DDX3X 综合征的细胞和分子决定因素

基本信息

批准号：
10633075
负责人：
Silvia De Rubeis
金额：
$ 49.52万
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：
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/10633075
关键词：
Ablation Accounting Address Adult Affect Affinity Chromatography Anxiety Awareness Behavior Behavioral Biochemistry Body Weight Brain Cell model Cell physiology Cognitive Cognitive deficits Corpus Callosum Cortical Malformation Data Defect Development Developmental Biology Developmental Delay Disorders Disease Electroporation Female Functional disorder Genes Genetic Genetic Diseases Goals Health Hyperactivity Individual Intellectual functioning disability Interdisciplinary Study Laboratories Link Literature Maps Measures Messenger RNA Methods Microgyria Missense Mutation Mission Molecular Molecular Target Motor Movement Disorders Mus Muscle hypotonia Mutant Strains Mice Mutation National Institute of Child Health and Human Development Neurobiology Neurodevelopmental Disorder Neurons Neurosciences Pathogenicity Pharmacological Treatment Phenotype Population Preclinical Testing Prevention Problem behavior Process Prosencephalon Protein Truncation Public Health RNA Helicase Reporting Research Ribosomes Sensory Social Behavior Standardization Syndrome Testing Therapeutic Translating Validation Viral X Inactivation autism spectrum disorder behavior test behavioral outcome behavioral phenotyping brain malformation clinical phenotype clinical sequencing disorder risk human tissue improved in utero in vivo innovation loss of function mutation mRNA Translation male motor behavior motor deficit mouse model nerve stem cell neurogenesis new therapeutic target novel novel therapeutic intervention social social deficits targeted treatment therapeutically effective translatome

项目摘要

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.

项目摘要我们对DDX3X综合征的理解有根本的差距，这是一种遗传状况女性中智障（ID）的2％，并由X连锁基因DDX3X中的突变引起。最多受影响的个体是具有DDX3X单倍不足的女性。最近使用细胞模型和子宫内的研究小鼠中的操作表明，DDX3X调节皮质神经发生和mRNA翻译神经元祖细胞。然而，缺乏针对DDX3X综合征构建有效性的小鼠模型阻碍了忠实地捕获观察到的认知，社会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。填补这些空白的迫切需要，因为在我们这样做之前，了解DDX3X综合征和开发有效的治疗剂仍然无法实现。解决这个问题未满足的需求，在我们的实验室中生成了小鼠建模DDX3X单倍弥补（DDX3X +/-）。这长期目标是阐明ID的病理生理学并确定治疗剂的靶标。总体目的是捕获DDX3X综合征基础的分子和细胞机制。中央假设是DDX3X决定了皮质投射神经元的形成，使认知，社会和运动功能，并通过调节发育中的皮质中的mRNA翻译来做到这一点。理由是，一旦我们确定了小鼠模型中DDX3X综合征和可靠表型的机制，可以开发和测试治疗剂。该假设将通过追求三个具体目标来检验：1）评估DDX3X综合征小鼠模型中的神经发育缺陷； 2）捕获分子 DDX3X综合征的小鼠模型中的缺陷； 3）将细胞功能与行为结果相关联 DDX3X突变小鼠。在AIM 1下，发展和成人的认知，社会和运动行为 DDX3X +/-小鼠将用标准化的行为电池进行测量。皮质投射神经元将是通过结合细胞和体内（例如，在子宫电穿孔）方法中，在DDX3X +/-小鼠中进行了研究。在下面 AIM 2，将使用翻译核糖体亲和力纯化绘制投影神经元中的DDX3X目标（陷阱）发现的方法及其基于病毒的开发（VTRAP）进行独立验证。在目标下 3，将测试有条件的DDX3X小鼠，该基因在前脑或特定皮质层中的基因将进行测试发展和成人行为。该提议具有创新性，因为它在很大程度上涉及的神经生物学未知ID基因，表征了DDX3X综合征的第一个小鼠模型。这也是创新的，因为它桥梁遗传学，生物化学，分子和细胞神经科学，发育生物学以及行为神经科学。应用很重要，因为它将提高我们对ID病理生理学的理解，同时为皮质生成开发新的灯光，这是大脑功能的基本过程。这些结果是预计会产生积极的影响，因为它们将为ID的新型治疗干预措施铺平道路。