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

• 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
• 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

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.

项目摘要 智力残疾（ID）是一种普遍存在的神经发育障碍， 治疗ID通常与运动问题共病，并且这些临床问题之间共享风险的性质 的表现并不完全清楚。在ID高风险基因中，与显著的运动相关的是 X连锁基因DDX 3X。DDX 3X的突变几乎只影响女性。DDX 3X编码一种RNA 解旋酶调节mRNA翻译，其在神经发育中的作用刚刚开始显现。的 DDX 3X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DDX 3X在大脑回路形成中的作用可能会提供一把新的钥匙来破译 ID及其与运动问题的共病性。为了解决这一未满足的需求，小鼠建模DDX 3X损失- 功能突变（Ddx 3x +/-）在我们的实验室中产生并表征。长期目标是绘制 ID的电路级驱动程序，并将其作为治疗目标进行评估。总体目标是审查 DDX 3X在塑造认知和运动控制的皮质-小脑回路中的作用。中央 假设DDX 3X调节皮质-小脑回路的发育， 运动功能基本原理是，一旦我们理解了ID的电路级驱动程序， 可以开发出精确的治疗方法。将通过追求两个具体目标来检验中心假设： 1)鉴定Ddx 3x突变小鼠小脑中改变的神经群体;以及，2）测试 Ddx 3x突变小鼠行为缺陷中的皮质-小脑通讯。根据目标1， 将使用单细胞RNA测序捕获Ddx 3x +/-小鼠的小脑群体。的体系结构 Ddx 3x +/-小鼠的小脑皮质将使用小脑群体的免疫染色进行分析， 在胚胎和出生后的生命中鉴定细胞特异性标志物。的形态发生和 将使用单胚胎原代培养物检查Ddx 3x +/-浦肯野细胞的突触发生。根据目标2， 在Ddx 3x +/-小鼠中通过同时追踪皮质-脑桥来分析皮质-脑桥-小脑通路 和脑桥小脑连接将生成浦肯野特异性Ddx 3x +/-条件性小鼠，并检测其 认知和运动行为使用完善的行为范例。这一建议具有创新性 因为它将通过绘制小脑细胞的图谱来定义一个基本上未知的ID基因的神经生物学， 受DDX 3X突变影响的电路及其与行为的关系。它也是创新的，因为它 衔接了发育生物学、细胞生物学、行为神经科学和单细胞转录组学。的 应用是重要的，因为它将促进我们对ID和共病运动缺陷的理解， 尤其是被忽视的女性它也很重要，因为它将揭示新的光， 小脑发育是大脑功能的基本过程。这些结果预计将有一个 积极影响，因为它们将为更好地预防和治疗ID铺平道路。