The Genetics and Cell Biology of the Epileptic Mouse Mutant Fitful

癫痫小鼠突变体的遗传学和细胞生物学

基本信息

批准号：
8269863
负责人：
REBECCA M BOUMIL
金额：
$ 31.45万
依托单位：
JACKSON LABORATORY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-06-01 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8269863
关键词：
Address Affect Age Age-Months Alleles Alternative Splicing Amino Acid Substitution Animal Genetics Anticonvulsants Antiepileptic Agents Ataxia Auxilins Biochemical Biological Assay Brain Canis familiaris Cellular biology Centronuclear myopathy Charcot-Marie-Tooth Disease Clathrin Collection Complex Data Defect Diagnosis Disease Dominant-Negative Mutation Dynamin Dynamin I Electroencephalography Electron Microscopy Endocytosis Environment Epilepsy Epileptogenesis Equilibrium Event Exercise Exocytosis Exons Functional disorder Future Gene Mutation Generations Genes Genetic Genets Goals Guanosine Triphosphate Phosphohydrolases Hippocampus (Brain)Homo Homologous Gene Homozygote Human Image Ion Channel Left Link Measurement Mediating Membrane Membrane Proteins Missense Mutation Modeling Molecular Molecular and Cellular Biology Monitor Mouse Strains Mus Mutant Strains Mice Mutate Mutation Neurologic Neurons Outcome Pathway interactions Pharmaceutical Preparations Phenotype Play Predisposition Process Protein Isoforms Proteins RNA Splicing Recurrence Recycling Regulation Research Role Seizures Severities Staging Synapses Synaptic Transmission Synaptic Vesicles Syndrome Time Transgenic Organisms Vesicle amphiphysin base experience improved in vivo Model insight intersectin 1 mutant nervous system disorder neurotransmission novel novel strategies programs protein protein interaction synaptojanin treatment strategy

项目摘要

DESCRIPTION (provided by applicant): Epilepsy is a collection of disorders that causes recurrent seizures. Often it is not the fault of a single gene but of complex genetic interactions. Each year, 200,000 new cases of epilepsy are diagnosed. In seventy percent of these cases there is no apparent cause. It is estimated that ten percent of these "new" cases will never obtain adequate seizure control even with treatment. Currently, the major focus of research is on improving and devising anticonvulsant medications, but the underlying mechanisms need to be uncovered and better understood to improve treatment strategies. To date, most of the known epilepsy genes are monogenic and responsible for human autosomal dominant forms of the disease. The more complex epilepsies are likely the result of polygenic interactions and environment. Our long-term goal is to elucidate the mechanisms by which a mutation in the Dynamin-1 (Dnm1) gene causes a complex seizure disorder. Dnm1 encodes a large multimeric GTPase necessary for activity-dependent membrane recycling in neurons, including synaptic vesicle endocytosis. Mice heterozygous for a novel spontaneous Dnm1 mutation - fitful - experience recurrent seizures, and homozygotes have more debilitating, often lethal seizures in addition to severe ataxia and neurosensory deficits. Fitful is a missense mutation in an exon that defines the Dnm1a isoform, leaving intact the alternatively spliced exon that encodes Dnm1b. We hypothesize that in fitful mice endocytosis is stalled at a checkpoint that requires the proper function of the Dnm1 isoforms to proceed from early endocytic events to later stage fission events. A delay in synaptic vesicle endocytosis would result in a deficiency of readily available vesicles for neurotransmission. Using fitful as a model of epilepsy, the following Specific Aims are proposed to address genetic questions related to the endocytic checkpoint: 1) Determine the genetic interactions involved in the endocytic checkpoint. We will use genetically disrupted mouse mutant strains of genes known to interact with Dnm1 at different stages of endocytosis to ask how disruption of endocytosis/fission at different points affects seizure phenotype differentially. 2) Dissect the potentially overlapping roles of the Dnm1 alternatively spliced isoforms in the checkpoint resulting in the seizure phenotype. Studies will utilize Dnm1 isoform specific mouse lines for animal genetic and seizure phenotype analysis. Collectively, these studies will define the involvement of Dnm1 in synaptic vesicle endocytosis. Additionally, they will give insight into the role that genes encoding endocytic proteins play in contributing to epilepsy. We suggest that using an in vivo model of dynamin dysfunction, such as fitful, will answer important questions not only about how dynamin functions in endocytosis, but also the important role dynamin plays in proper synaptic transmission.

描述（由申请人提供）：癫痫是导致癫痫发作的疾病的集合。通常，这不是一个基因的错，而是复杂的遗传相互作用的断层。每年，诊断出200,000例新的癫痫病病例。在这些情况中，有70％没有明显的原因。据估计，这些“新”病例中有百分之十，即使通过治疗也将永远无法获得足够的癫痫发作控制。目前，研究的主要重点是改善和设计抗惊厥药物，但是需要发现和更好地理解潜在的机制，以改善治疗策略。迄今为止，大多数已知的癫痫基因都是单基因的，并且负责人常染色体显性疾病形式。更复杂的癫痫可能是多基因相互作用和环境的结果。我们的长期目标是阐明Dynamin-1（DNM1）基因突变会导致复杂的癫痫发作的机制。 DNM1编码用于神经元中活性依赖性膜回收所需的大型多聚体GTPase，包括突触囊泡内吞作用。用于一种新型自发DNM1突变的杂合子 - 适当的 - 经历复发性癫痫发作和纯合子还具有更大的衰弱，除了严重的共济失调和神经感觉缺乏外，通常还具有致命性癫痫发作。适当的是定义DNM1A同工型的外显子中的错义突变，使编码DNM1B的剪接外显子完整。我们假设在适当的小鼠中，内吞作用停滞在检查点，该检查点需要DNM1同工型的适当功能才能从早期内吞事件到以后的阶段裂变事件。突触囊泡内吞作用的延迟会导致可随时可用的神经传递囊泡的缺乏。提出了使用适当的癫痫模型，提出了以下特定目的来解决与内吞检查点有关的遗传问题：1）确定内吞检查点中涉及的遗传相互作用。我们将使用已知在内吞作用的不同阶段与DNM1相互作用的基因遗传破坏的小鼠突变菌株询问不同点内吞和裂变的破坏如何影响癫痫发作表型。 2）剖析DNM1在检查点中剪接的同工型的潜在重叠作用，从而导致癫痫发作表型。研究将利用DNM1同工型特异性小鼠系进行动物遗传和癫痫发作表型分析。总的来说，这些研究将定义DNM1参与突触囊泡内吞作用。此外，他们将深入了解编码内吞蛋白在癫痫中发挥作用的基因的作用。我们建议，使用Dynamin功能障碍的体内模型（例如FITFUL）将不仅回答有关Dynamin在内吞作用中的功能的重要问题，而且还会回答Dynamin在适当突触传播中的重要作用。