权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The Circadian Molecular Clock is a Biomarker for Epilepsy in Focal Cortical Dysplasia

昼夜节律分子钟是局灶性皮质发育不良中癫痫的生物标志物

基本信息

批准号：
10302615
负责人：
Judy Shih-Hwa Liu
金额：
$ 8.14万
依托单位：
BROWN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-02-01 至 2023-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10302615
关键词：
Ablation Action Potentials Alleles Behavior Behavioral Behavioral Symptoms Binding Biochemical Biological Markers Brain Cells Childhood Citrates Citric Acid Cycle Cognitive Complex Cortical Dysplasia Coupled Defect Developmental Delay Disorders Disease Electroencephalogram Electrophysiology (science)Epilepsy Epileptogenesis Equilibrium Excitatory Synapse Functional disorder Generations Genes Genetic Glutamates Growth Hippocampus (Brain)Human Inhibitory Synapse Knockout Mice Laboratories Lead Life Link Measures Medical Membrane Mendelian disorder Messenger RNA Metabolic Missense Mutation Modeling Mus Mutant Strains Mice Mutation Neurobehavioral Manifestations Neurons Neurosciences Neurotransmitters Newly Diagnosed Output Parents Patients Pattern Property Publishing Refractory Research Research Personnel SLC13A5 deficiency Seizures Severities Sodium Status Epilepticus Techniques Testing Training base career childhood epilepsy circadian citrate carrier comorbidity excitatory neuron experimental study gain of function gamma-Aminobutyric Acid gene function graduate student infancy meetings metabolomics molecular clock mouse model multidisciplinary mutant parent grant patch clamp pediatric patients pre-doctoral therapeutic target transcription factor

项目摘要

PROJECT SUMMARY The parent R01 is based on our study of medically refractory pediatric epilepsy, where we identified decreased mRNA levels of the transcription factor, Circadian Locomotor Output Cycles Kaput (Clock), compared with non- epileptic brain. Mice with targeted deletion of the Clock gene in excitatory neurons have spontaneous seizures, leading us to hypothesize that loss of Clock leads to circuit dysfunction and epilepsy. In both the parent R01 and the proposed new experiments, we study pediatric epilepsy. In this supplement, we investigate a rare, newly diagnosed form of genetic infantile epilepsy and developmental delay caused by mutations in SLC13A5, a sodium-coupled citrate transporter, using models that we already have in the laboratory, and using the same techniques that we are using in the parent grant i.e. video EEG and whole cell patch-clamp electrophysiology in hippocampal neurons. Slc13a5 mutations result in decreased intracellular citrate levels, indicating metabolic defect. Since we have extended our parent studies of Clock gene into metabolomics, the proposed studies are in keeping with the scope and overall hypothesis that metabolic defects underlie circuit dysfunction in epilepsy. Analysis of Slc13a5 as a less complex, single gene disorder will help us understand important links between metabolic signatures and epilepsy. We generated mouse models containing two of the most commonly found Slc13a5 missense mutations in pediatric patients. Preliminary characterization revealed an unexpected gain-of-function effect of a sodium-binding domain missense mutation i.e. more severe seizures, meeting the definition of status epilepticus, in striking contrast to Slc13a5 gene ablation, which does not produce seizures, indicating altered gene function. We hypothesize that aberrant cortical and hippocampal activity arises from altered neurotransmitter levels and electrophysiological properties at excitatory and inhibitory synapses. We will test our hypothesis in two Aims. In Aim 1, we will investigate changes in epilepsy associated with Slc13a5 mutations in comparison with Slc13a5 ablation. Using video electroencephalogram (EEG), we plan to measure seizure thresholds in these mice, interictal epileptiform abnormalities, epilepsy severity, and baseline EEG patterns. In Aim 2, we will determine neurotransmitter changes associated with Slc13a5 mutations, and identify, by patch-clamp electrophysiology, how altered citrate or TCA cycle intermediates lead to depletion of glutamate and GABA levels. We will also investigate action potential generation threshold, firing patterns, and membrane properties to determine changes in excitatory-inhibitory balance. Analysis of hetero- and homozygous mouse null and missense mutants would help determine how the mutant allele gains function or interferes with normal gene activity. These studies constitute a major part of a thesis project for our URM graduate student, whose multi-disciplinary training plans for career growth as a neuroscience investigator are outlined in this proposal. Understanding the genetic and metabolic mechanisms may lead to new treatments for epilepsy and its associated cognitive and behavioral symptoms.

项目总结