Elucidating pathogenic mechanisms in STRADA-related brain malformation and epilepsy

阐明 STRADA 相关脑畸形和癫痫的致病机制

基本信息

批准号：
10681308
负责人：
Louis Tuong Chinh Dang
金额：
$ 43.31万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-15 至 2027-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10681308
关键词：
3-Dimensional Affect Antiepileptogenic Biological Assay Brain Calcium Cell Culture Techniques Cell Therapy Cells Cerebrum Child Complex Cortical Dysplasia Cortical Malformation Data Development Disease Dorsal Effectiveness Electrophysiology (science)Epilepsy Epileptogenesis Etiology FRAP1 gene Feedback Genes Genetic Genetic study Goals Human Hyperactivity Image Immunohistochemistry Impaired cognition Impairment Individual Intellectual functioning disability Interneurons Knowledge Measures Megalencephaly Modeling Morbidity - disease rate Morphology Mutation Neuroglia Neuronal Differentiation Neurons Organoids Outcome Pathogenesis Pathogenicity Pathway interactions Patients Pharmaceutical Preparations Phenotype Polyhydramnios, megalencephaly, and symptomatic epilepsy Process Proliferating Prosencephalon Radial Seizures Signal Pathway Signal Transduction Sirolimus Structure Syndrome Testing Therapeutic Tissue-Specific Gene Expression Transcription Alteration Transplantation Tuberous Sclerosis Up-Regulation Work analog autism spectrum disorder brain abnormalities brain malformation cell fate specification cell type disability excitatory neuron glial cell development in vitro Model induced pluripotent stem cell inhibitory neuron innovation insight loss of function loss of function mutation mTORopathies malformation migration mortality multi-electrode arrays mutant neural neurodevelopment neurogenesis novel novel therapeutics pharmacologic prevent resistance mechanism response single-cell RNA sequencing stem cell model stem cells targeted treatment therapeutic target therapy development treatment strategy

项目摘要

PROJECT SUMMARY Epilepsy is a major cause of morbidity, mortality, disability, and expense, and affects over 470,000 children in the U.S. While many medications to control seizures have been developed, about 30% of patients do not respond to medications, and to date, there are no medications that can prevent or halt the progression of epilepsy. Recently, many genetic causes of epilepsy have been identified, providing insights into pathways involved in epileptogenesis. Mutations causing hyperactivity of the mTOR pathway (so-called “mTORpathies”) have emerged as an important cause of cerebral malformations and epilepsy, including tuberous sclerosis complex, focal cortical dysplasia, and polyhydramnios, megalencephaly, and symptomatic epilepsy (PMSE) syndrome, which is associated with severe epilepsy and intellectual disability and is caused by a loss-of- function in the STRADA gene. Inhibition of the mTOR pathway with rapamycin or its analogs can help in mTORopathies, but many individuals still have seizures that do not respond. Prior studies generated stem cells from individuals with PMSE and differentiated them into excitatory neurons in 2-D culture and dorsally-fated human cerebral organoids, 3-D neural structures that resemble the developing cortex and predominantly contain excitatory neurons. The PMSE organoids demonstrated mTOR hyperactivity, increased size, abnormal morphology, delayed neuronal differentiation, and an increase in outer radial glia, a progenitor cell that is responsible for the expanded size of the human brain. These findings explain megalencephaly in PMSE, but the intermediate mechanisms by which STRADA loss-of-function results in these observed phenotypes is not known. Furthermore, the effect of STRADA loss-of-function on inhibitory interneurons that originate from ventral forebrain structures is not known. Abnormal inhibitory interneurons are a major cause of epilepsy and autism, both prominent features of mTORopathies. This proposal will test the central hypothesis that loss of STRADA causes cortical malformation by mTOR complex 1 hyperactivity, and that inhibitory interneuron development is also impaired, resulting in epilepsy. This innovative proposal will use dorsally-fated organoids to identify which signaling pathway alterations downstream of STRADA result in altered cortical development, and will determine whether compensatory feedback signals hinder the effectiveness of rapamycin treatment (Aim 1). We will also generate fusions between ventrally-fated and dorsally-fated organoids to study interneuron development, interneuron migration, cell-type specific transcriptional alterations (Aim 2), as well as neuronal network hyperexcitability that can result in epilepsy (Aim 3). The proposed study will have significant impact because understanding the signaling pathways and cell types responsible for pathogenesis in PMSE will provide a platform to develop mechanistically driven therapies that can halt or reverse epileptogenesis for mTORopathies, and our findings should be applicable to epilepsies in a broader context.

项目摘要癫痫是发病率，死亡率，残疾和费用的主要原因，在470,000多名儿童中影响美国虽然已经开发了许多控制癫痫的药物，但约有30％的患者没有对药物的反应，迄今为止，没有药物可以阻止或停止癫痫。最近，已经鉴定出许多癫痫病因的遗传原因，为途径提供了见解参与癫痫发生。引起MTOR途径多动症的突变（所谓的“ mtorPathies”）已成为脑畸形和癫痫病的重要原因，包括结节性硬化症复杂的，局灶性皮质发育不良和多氢气，大脑脑和症状癫痫（PMSE）综合征，与严重的癫痫和智力障碍有关，是由丧失丧失引起的 strada基因的功能。用雷帕霉素或其类似物抑制mTOR途径可以帮助 mtoropathies，但许多人仍然有没有反应的癫痫发作。先前的研究产生了干细胞来自PMSE的个体，并将其区分为2-D培养的兴奋性神经元和背命令的神经元人脑器官，3-D神经元结构，类似于发育的皮质，主要是包含兴奋的神经元。 PMSE类器官表现出MTOR多动症，大小增加，异常形态学，延迟神经元分化以及外部radial胶质神经胶质的增加，祖细胞是一种负责人脑的扩大规模。这些发现解释了PMSE中的大脑，但是在这些观察到的表型中，strada功能丧失导致功能丧失的中间机制不是已知。此外，strada功能丧失对起源于抑制性中间神经元的影响腹侧前脑结构尚不清楚。异常抑制性神经元是癫痫的主要原因，自闭症，这是mtoropathies的两个突出特征。该提案将检验损失的中心假设 strada引起MTOR复合物1多动症的皮质畸形，并且抑制性中间神经元发育也受到损害，导致癫痫。该创新的建议将使用背命令的类器官确定strada下游的哪些信号通路改变会导致皮质发育改变，并将确定补偿性反馈是否会阻碍雷帕霉素治疗的有效性（目标1）。我们还将在腹侧命令和背命令器官之间产生融合以研究中间神经元的发育，中间神经元迁移，细胞类型特异性转录改变（AIM 2）以及神经元网络过度刺激性可能导致癫痫病（AIM 3）。拟议的研究将具有重要的影响是因为了解负责PMSE发病机理的信号通路和细胞类型将提供一个平台来开发机械驱动的疗法，该疗法可以停止或反向癫痫发生 mtoropathies，我们的发现应适用于在更广泛的背景下发作。