The development of cortico-cerebellar circuits in a genetic form of intellectual disability

遗传性智力障碍中皮质小脑回路的发育

基本信息

批准号：
10348976
负责人：
Silvia De Rubeis
金额：
$ 46.51万
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：
2021-09-15 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10348976
关键词：
Address Adult Affect Architecture Axon Behavior Behavioral Behavioral Paradigm Brain Cells Cellular biology Cerebellar Cortex Cerebellar malformation Cerebellum Chromosome Mapping Clinical Cognition Cognitive Cognitive deficits Communication Complex Cortical Malformation Data Defect Dependovirus Development Developmental Biology Developmental Delay Disorders Disease Embryo Female Gait Genes Genetic Genetic Translation Goals Hyperactivity Impairment Individual Intellectual functioning disability Intervention Label Laboratories Life Light Link Literature Maps Memory impairment Methods Mission Molecular Morphogenesis Motor Movement Disorders Mus Muscle Hypertonia Muscle hypotonia Mutant Strains Mice Mutation National Institute of Neurological Disorders and Stroke Nature Neurobiology Neurodevelopmental Disorder Neurons Neurosciences Pathway interactions Pharmacological Treatment Pontine structure Population Precision therapeutics Prevention Process Public Health Purkinje Cells RNA Helicase Regulation Research Role Shapes Suggestion Testing X Inactivation anxiety-like behavior base clinical phenotype cognitive function comorbidity conditional mutant emotional functioning fear memory high risk hindbrain improved in utero innovation loss of function mutation male motor behavior motor control motor deficit motor disorder mouse model neglect neurodevelopment neurogenesis neuromechanism novel postnatal prenatal protein expression relating to nervous system risk sharing risk variant single-cell RNA sequencing synaptogenesis therapeutic target transcriptomics

项目摘要

PROJECT SUMMARY Intellectual disability (ID) is a prevalent neurodevelopmental disorder with no effective pharmacological treatment. ID is often co-morbid with motor problems, and the nature of shared risk between these clinical manifestations is not fully understood. Amongst the ID high-risk genes with significant motor involvement is the X-linked gene DDX3X. Mutations in DDX3X affect almost exclusively females. DDX3X encodes an RNA helicase regulating mRNA translation, and its role in neurodevelopment is just beginning to emerge. The circuit-level changes induced by DDX3X mutations are unknown. There is a critical need to fill these gaps because understanding the role of DDX3X in the formation of brain circuits might offer a new key to decipher ID and its co-morbidity with motor problems. To address this unmet need, a mouse modeling DDX3X loss-of- function mutations (Ddx3x+/-) was generated and characterized in our laboratory. The long-term goal is to map the circuit-level drivers of ID and assess them as therapeutic targets. The overall objective is to examine the role of DDX3X in shaping cortico-cerebellar circuits contributing to cognition and motor control. The central hypothesis is that DDX3X regulates the development of cortico-cerebellar circuits subserving cognitive and motor function. The rationale is that, once we understand the circuit-level drivers of ID, mechanism-based precision therapeutics can be developed. The central hypothesis will be tested by pursuing two Specific Aims: 1) Identify the neural populations altered in the cerebellum of Ddx3x mutant mice; and, 2) Test the role of cortico-cerebellar communication in behavioral deficits of Ddx3x mutant mice. Under Aim 1, the alterations in cerebellar populations of Ddx3x+/- mice will be captured using single-cell RNA sequencing. The architecture of the cerebellar cortex in Ddx3x+/- mice will be analyzed using immunostaining of cerebellar populations with authenticated cell-specific markers during embryonic and postnatal life. The morphogenesis and synaptogenesis of Ddx3x+/- Purkinje cells will be examined using single-embryo primary cultures. Under Aim 2, the cortico-ponto-cerebellar pathway will be analyzed in Ddx3x+/- mice by simultaneously tracing cortico-pons and ponto-cerebellar connections. Purkinje-specific Ddx3x+/- conditional mice will be generated and tested for cognition and motor behavior using well-established behavioral paradigms. This proposal is innovative because it will define the neurobiology of a largely unknown ID gene by mapping the cerebellar cells and circuits affected by DDX3X mutations, and their relationship with behavior. It is also innovative because it bridges developmental biology, cellular biology, behavioral neuroscience, and single-cell transcriptomics. The application is significant because it will advance our understanding of ID and co-morbid motor deficits, and look specifically at females, which have been neglected. It is also significant because it will shed new light on cerebellar development, a fundamental process for brain function. These results are expected to have a positive impact because they will pave the way for better methods for prevention and treatment of ID.

项目概要智力障碍（ID）是一种普遍存在的神经发育障碍，目前尚无有效的药物治疗方法治疗。智力障碍通常与运动问题同时存在，并且这些临床疾病之间共享风险的性质的表现形式尚未完全理解。在与运动相关的 ID 高风险基因中，有 X连锁基因DDX3X。 DDX3X 突变几乎只影响女性。 DDX3X 编码 RNA 解旋酶调节 mRNA 翻译，其在神经发育中的作用才刚刚开始显现。这 DDX3X 突变引起的电路水平变化尚不清楚。迫切需要填补这些空白因为了解 DDX3X 在大脑回路形成中的作用可能会为破译大脑回路提供新的钥匙智力障碍及其与运动问题的合并症。为了解决这一未满足的需求，模拟 DDX3X 的鼠标丢失了功能突变（Ddx3x+/-）是在我们的实验室中生成和表征的。长期目标是绘制地图 ID 的电路级驱动因素并将其作为治疗目标进行评估。总体目标是检查 DDX3X 在塑造有助于认知和运动控制的皮质小脑回路中的作用。中央假设 DDX3X 调节皮质小脑回路的发育，从而促进认知和运动功能。基本原理是，一旦我们了解了 ID 的电路级驱动因素，基于机制的可以开发精准疗法。中心假设将通过追求两个具体目标来检验： 1) 鉴定Ddx3x突变小鼠小脑中发生改变的神经群；以及，2) 测试角色 Ddx3x 突变小鼠行为缺陷中的皮质小脑通讯。在目标 1 下，改变 Ddx3x+/- 小鼠的小脑群体将使用单细胞 RNA 测序进行捕获。的架构将使用小脑群体的免疫染色来分析 Ddx3x+/- 小鼠的小脑皮质在胚胎和出生后生命期间经过验证的细胞特异性标记。形态发生和 Ddx3x+/-浦肯野细胞的突触发生将使用单胚胎原代培养物进行检查。在目标 2 下，通过同时追踪皮质脑桥，将在 Ddx3x+/- 小鼠中分析皮质-脑桥-小脑通路和脑桥小脑连接。将生成浦肯野特异性 Ddx3x+/- 条件小鼠并进行测试使用完善的行为范式进行认知和运动行为。这个提议很有创新性因为它将通过绘制小脑细胞图谱来定义一个很大程度上未知的 ID 基因的神经生物学受 DDX3X 突变影响的回路及其与行为的关系。它也具有创新性，因为它连接发育生物学、细胞生物学、行为神经科学和单细胞转录组学。这应用很重要，因为它将增进我们对智力障碍和共病运动缺陷的理解，并且看看尤其是女性，这一点一直被忽视。它也很重要，因为它将为我们提供新的线索小脑发育，大脑功能的基本过程。这些结果预计将有积极影响，因为它们将为预防和治疗智力障碍的更好方法铺平道路。