Role of LGI1 in Autosomal Dominant Lateral Temporal Lobe Epilepsy

LGI1 在常染色体显性遗传性外侧颞叶癫痫中的作用

基本信息

批准号：
7525735
负责人：
MATTHEW P ANDERSON
金额：
$ 33.47万
依托单位：
BETH ISRAEL DEACONESS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-08-18 至 2012-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7525735
关键词：
2-tyrosine 3-Dimensional ADAM Family Protein Acute Address Afferent Neurons Animals Antibodies Auditory Axon Bacterial Artificial Chromosomes Bacterial Genes Binding Brain Brain Diseases Cells Chromosome Pairing Complex Computer software Count Cytoplasmic Granules DLG4 gene DNA Data Dendrites Dependence Development Dimerization Disease Dominant-Negative Mutation Down-Regulation Engineering Epilepsy Figs - dietary Frequencies Gene Expression Genes Genomics Genotype Glioma Glutamate Receptor Glutamates Goals Haploidy Hippocampus (Brain)Human Immunoprecipitation In Vitro Inferior Colliculus Inherited Integrins Ion Channel LGI1 gene Lateral Learning Length Leucine Life Link Localized Long-Term Potentiation Measures Medial Mediating Membrane Methods Modeling Molecular Mus Mutate Mutation N-Methyl-D-Aspartate Receptors N-Methylaspartate NR2B NMDA receptor Neurons Numbers PTK2 gene Pathway interactions Pattern Perforant Pathway Physiologic pulse Potassium Channel Probability Process Property Protein Binding Protein Kinase Protein Tyrosine Kinase Protein-Serine-Threonine Kinases Proteins Public Health Pulse taking RNA Splicing Receptor Down-Regulation Research Role Sensory Series Signal Pathway Signal Transduction Slice Staining method Stains Structure of molecular layer of cerebellar cortex Synapses Synaptic Transmission Synaptic Vesicles Synaptic plasticity Temporal Lobe Epilepsy Terminator Codon Testing Thalamic structure Time Transcript Transgenic Mice Transgenic Organisms Vesicle Western Blotting base biocytin dendrotoxin density dentate gyrus dimer early childhood entorhinal cortex gamma-Aminobutyric Acid human LGI1 protein in vivo inhibitor/antagonist insight kinase inhibitor mutant nerve supply neural circuit novel patch clamp postnatal postsynaptic presynaptic prevent protein expression receptor receptor function reconstruction response src-Family Kinases therapeutic target transmission process

项目摘要

DESCRIPTION (provided by applicant): A recently discovered human epilepsy gene, LGI1 (leucine-rich glioma-inactivated; mutated to cause human autosomal dominant lateral temporal lobe epilepsy or ADLTE) encodes a protein secreted at glutamate synapses during postnatal glutamate synapse development. Consequently, we hypothesize that LGI1 might promote epilepsy through a novel mechanism, by regulating postnatal glutamate synapse maturation. We propose ADLTE mutant LGI1 acts as a dominant negative to inhibit native LGI1 function and arrest maturation. To directly address our hypothesis and contrast the functional effects of epilepsy-associated mutant LGI1 with those of excess wild-type LGI1 on native neural circuits, we created transgenic mice using bacterial artificial chromosomes (BAC) carrying a large 226 kb fragment of mouse genomic DNA encoding the full-length LGI1 gene. The ADLTE 835delC mutation introduced a premature translational stop codon to generate a truncated LGI1 protein. The full-length gene BAC transgenic approach is important to maintain native patterns of gene expression and transcript splicing in order to assess the genes effects on the glutamate synapse development process in vivo. LGI1 is heavily expressed presynaptically at medial entorhinal cortex perforant pathway glutamate synapses innervating dentate granule neurons (MPP- dentate) and also separately in a synapse targeting thalamus. Our overall goal is to define the cellular basis for human ADLT epilepsy. We specifically test whether excess LGI1 magnifies and mutant LGI1 blocks maturation of the following glutamate synapse properties during the postnatal periods when it becomes expressed and throughout adulthood in dentate gyrus and thalamus. We examine: 1) presynaptic glutamate release down-regulation and role of Kv1.1 K+ channel activity; 2) postsynaptic NR2B NMDA receptor current and synaptic plasticity down-regulation, PSD95-Src complex formation, and the role of Src kinase activity; and 3) dendrite branch (e.g., dentate) and axon input (e.g., thalamus) pruning. This murine model of human ADLT epilepsy could link a novel human epilepsy gene to the arrest of glutamate synapse maturation and potentially defining a cellular basis for human seizure disorders beyond ADLTE. PUBLIC HEALTH RELEVANCE: This project seeks to identify the cellular basis of the inherited human epilepsy disorder caused by mutations in LGI1, a secreted synaptic protein. The results should provide new insights into the cellular and molecular basis of human epilepsy, and help identify new potential therapeutic targets to treat this common brain disorder.

描述（由申请人提供）：最近发现的人类癫痫基因 LGI1（富含亮氨酸的神经胶质瘤失活；突变导致人类常染色体显性外侧颞叶癫痫或 ADLTE）编码在出生后谷氨酸突触发育过程中谷氨酸突触分泌的蛋白质。因此，我们假设 LGI1 可能通过调节出生后谷氨酸突触成熟的新机制促进癫痫。我们提出 ADLTE 突变体 LGI1 作为显性失活抑制天然 LGI1 功能并阻止成熟。为了直接证实我们的假设并对比癫痫相关突变体 LGI1 与过量野生型 LGI1 对天然神经回路的功能影响，我们使用携带 226 kb 大小鼠基因组 DNA 片段的细菌人工染色体 (BAC) 创造了转基因小鼠编码全长 LGI1 基因。 ADLTE 835delC 突变引入了过早翻译终止密码子以生成截短的 LGI1 蛋白。全长基因 BAC 转基因方法对于维持基因表达和转录剪接的天然模式非常重要，以便评估基因对体内谷氨酸突触发育过程的影响。 LGI1 在支配齿状颗粒神经元 (MPP-齿状) 的内侧内嗅皮层穿通通路谷氨酸突触突触前大量表达，并且也在针对丘脑的突触中单独表达。我们的总体目标是确定人类 ADLT 癫痫的细胞基础。我们特别测试了过量的 LGI1 是否会放大和突变的 LGI1 是否会在出生后时期（当它表达时）以及整个成年期在齿状回和丘脑中阻止以下谷氨酸突触特性的成熟。我们检查：1) 突触前谷氨酸释放下调和 Kv1.1 K+ 通道活性的作用； 2）突触后NR2B NMDA受体电流和突触可塑性下调、PSD95-Src复合物形成以及Src激酶活性的作用； 3）树突分支（例如齿状）和轴突输入（例如丘脑）修剪。这种人类 ADLT 癫痫的小鼠模型可以将一种新的人类癫痫基因与谷氨酸突触成熟的停滞联系起来，并可能定义 ADLTE 之外的人类癫痫疾病的细胞基础。公共健康相关性：该项目旨在确定由 LGI1（一种分泌性突触蛋白）突变引起的遗传性人类癫痫病的细胞基础。研究结果将为人类癫痫的细胞和分子基础提供新的见解，并有助于确定治疗这种常见脑部疾病的新的潜在治疗靶点。