Pathomechanisms of SCN3A-related neurodevelopmental disorder

SCN3A相关神经发育障碍的发病机制

• 批准号: 10544490
• 负责人: ETHAN M GOLDBERG
• 金额: $ 52.83万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10544490
• 关键词: Acceleration; Acute; Alleles; Anticonvulsants; Biological Models; Biophysics; Birth; Brain; CRISPR correction; CRISPR/Cas technology; Calcium; Cell Line; Cells; Cerebral cortex; Chronic; Clinical; Cortical Malformation; Data; Defect; Dependence; Development; Disease; Electrophysiology (science); Electroporation; Embryo; Epilepsy; Exhibits; Functional disorder; Gene Mutation; Genes; Genetic Variation; Heterozygote; Human; Immunohistochemistry; Impairment; In Vitro; Inherited; Intellectual functioning disability; Ion Channel; Knock-in Mouse; Lead; Link; LoxP-flanked allele; Maps; Mediating; Membrane Potentials; Modeling; Morphology; Mus; Mutant Strains Mice; Neurites; Neurodevelopmental Disability; Neurodevelopmental Disorder; Neurons; Neurosciences; Pathogenicity; Pathologic; Pathology; Patients; Pharmacology; Physiology; Placenta; Pre-Clinical Model; Prevention; Preventive measure; Preventive therapy; Property; Prosencephalon; Registries; Research; Resistance; Role; Severities; Severity of illness; Slice; Sodium; Sodium Channel; System; Testing; Time; Translating; Variant; biophysical properties; brain malformation; channel blockers; clinical application; clinical phenotype; cohort; experimental study; gain of function; genetic variant; human disease; human stem cells; in utero; induced pluripotent stem cell; innovation; loss of function; malformation in cortical development; migration; mouse model; mutant; neuronal excitability; novel; novel therapeutics; overexpression; pharmacologic; postnatal; pregnant; prevent; pup; severe intellectual disability; targeted treatment; tool; variant of unknown significance; voltage; voltage clamp

PROJECT SUMMARY Recently-described SCN3A-related neurodevelopmental disorder (SCN3A-NDD) is caused by pathogenic variants in the gene SCN3A, which encodes the sodium (Na+) channel subunit Nav1.3. SCN3A-NDD is a devastating condition defined by treatment-resistant epilepsy and severe/profound intellectual disability (ID); surprisingly, many patients also exhibit malformation of cortical development (MCD), a developmental disturbance in the structural formation of the cerebral cortex of the brain, suggesting functional roles for Nav1.3 during embryological development. How genetic variants in SCN3A leads to epilepsy and neurodevelopmental disability, and how SCN3A variants lead to MCD, is unknown. Research is required to clarify the functional role of Nav1.3 during early brain development and to progress towards novel therapies or preventative measures for SCN3A-NDD, which is currently and untreatable disorder. This 5-year collaborative application employs novel tools and innovative neuroscience approaches to test the hypothesis that pathogenic variants in SCN3A lead to a disorder that includes epilepsy and MCD via dysregulated Na+ currents in migrating neurons of the developing cerebral cortex. Electrophysiological recordings in heterologous cell systems indicate that pathogenic SCN3A variants found in patients with SCN3A-NDD largely produce Na+ channels that exhibit gain of function due to increased persistent current and alterations in the voltage dependence of channel activation, which increase channel activity. However, the mechanistic basis of observed variability in epilepsy severity and presence or absence of MCD, is unclear. And how altered channel activity impacts the function of neurons has not been investigated. Proposed experiments will determine the relationship between specific SCN3A variants and correlated clinical phenotype (epilepsy, MCD, severity of ID) in a large cohort of human patients with SCN3A-NDD. To link SCN3A variants to dysfunction of ion channels and neurons, we will compare the biophysical properties of normal Na+ channels to channels containing variant Nav1.3; test cell-intrinsic effects of SCN3A variants in neurons generated from induced pluripotent stem cells from human SCN3A-NDD patients; and test effects of variant overexpression via in utero electroporation of mouse embryo followed by electrical recording in brain slices (Aim 1). The impact of variant SCN3A on the morphology of immature neurons and cytoarchitecture of the developing cerebral cortex will inform the role of SCN3A in development (Aim 2). To translate these findings towards clinical applications, we will attempt to ameliorate features of SCN3A-NND in advanced model systems, including a newly generated conditional point mutant mouse, via targeted manipulation of pathogenic Nav1.3-mediated Na+ current (Aim 3). Results will provide novel information on the role of Nav1.3 during brain development, and will define the pathogenic mechanisms of SCN3A-NDD towards development of novel, targeted therapies in human patients.

项目摘要 最近描述的SCN3A相关神经发育障碍（SCN3A-NDD）是由致病性引起的 基因SCN3A中的变体，该变体编码钠（Na+）通道亚基NAV1.3。 SCN3A-NDD是一个 由耐药性癫痫和严重/深刻的智力残疾（ID）定义的毁灭性状况； 令人惊讶的是，许多患者还表现出皮质发育畸形（MCD），这是一种发育 大脑大脑皮层的结构形成中的干扰，表明NAV1.3的功能作用 在胚胎发展过程中。 SCN3A中的遗传变异如何导致癫痫和神经发育 残疾以及SCN3A变体如何导致MCD，尚不清楚。需要研究以阐明功能角色 NAV1.3在早期大脑发育期间的发展，并朝着新的疗法或预防措施迈进 对于目前和不可治疗的疾病的SCN3A-NDD。 这个为期5年的协作应用程序采用新颖的工具和创新的神经科学方法来测试 假设SCN3A中的致病变异导致疾病，其中包括癫痫和MCD通过 在发育中的大脑皮质的迁移神经元中，Na+电流失调。 异源细胞系统中的电生理记录表明，在 SCN3A-NDD的患者在很大程度上产生了由于增加而表现出功能增长的Na+通道 持续的电流和通道激活电压依赖性的变化，这增加了通道 活动。但是，观察到的机械基础是癫痫严重程度以及存在或不存在的可变性 MCD，不清楚。以及尚未研究神经元功能的通道活性如何影响。 提出的实验将确定特定的SCN3A变体与相关临床之间的关系 在大量的SCN3A-NDD患者中，表型（癫痫，MCD，ID的严重程度）。链接 SCN3A变体与离子通道和神经元的功能障碍，我们将比较 正常的Na+通道到包含变体NAV1.3的通道； SCN3A变体的测试细胞中性效应 由人类SCN3A-NDD患者引起的多能干细胞产生的神经元；和测试效果 小鼠胚胎的子宫电穿孔中的变体过表达，然后在大脑中进行电记录 切片（目标1）。变体SCN3A对未成熟神经元形态的影响和细胞结构结构的影响 发展中的大脑皮层将告知SCN3A在开发中的作用（AIM 2）。翻译这些 针对临床应用的发现，我们将尝试改善高级模型中SCN3A nnd的特征 通过针对致病性操纵的系统，包括新生成的条件点突变小鼠 NAV1.3介导的Na+电流（AIM 3）。 结果将提供有关NAV1.3在大脑发育过程中的作用的新信息，并将定义 SCN3A-NDD的致病机制用于开发人类患者的新型靶向疗法。