Understanding the Etiology of CASK Associated Epileptic Encephalopathy

了解 CASK 相关癫痫性脑病的病因

• 批准号: 10211576
• 负责人: Sarika Srivastava
• 金额: $ 41.54万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10211576
• 关键词: APBA1 gene; ATP phosphohydrolase; Acetates; Acute; Adult; Affect; Affinity Chromatography; Age; Age of Onset; American; Animal Model; Apoptosis; Behavioral; Biogenesis; Biological Assay; Biological Markers; Brain; Brain Diseases; Calcium; Cells; Cessation of life; Childhood; Clinical; Cognitive; DNA Sequence Alteration; DNA cassette; Disease; Dopamine; Early Infantile Epileptic Encephalopathy; Electroencephalogram; Electrophysiology (science); Endoplasmic Reticulum; Energy Metabolism; Epilepsy; Equilibrium; Etiology; Exhibits; Face; Functional disorder; Gene Expression; General Population; Genes; Glucose; Glutamate Receptor; Glutamates; Glutaminase; Glutamine; Goals; Growth; Hydroxybutyrates; Impaired cognition; Impairment; In Situ Nick-End Labeling; Infantile spasms; Inhibitory Synapse; Intervention; Isotopes; Ketone Bodies; Knockout Mice; Label; Lead; Life; Link; Literature; Mammals; Mass Spectrum Analysis; Measures; Membrane; Messenger RNA; Metabolic; Metabolic Pathway; Metabolism; Methods; Mitochondria; Mitochondrial Proteins; Modeling; Multienzyme Complexes; Mus; Mutation; Myoclonus; NADH; NMR Spectroscopy; Neomycin; Neonatal; Neuroglia; Neurons; Neurotransmitters; Nicotinamide Mononucleotide; Outer Mitochondrial Membrane; Oxidative Phosphorylation; Pathogenicity; Pathway interactions; Patients; Pharmacology; Phenotype; Physiology; Play; Prognosis; Protein Interaction Mapping; Proteins; Pyruvate; Reactive Oxygen Species; Recurrence; Reflex action; Residual state; Role; SIRT1 gene; Scanning Electron Microscopy; Slice; Spasm; Structural defect; Structure; Synapses; Testing; Therapeutic; Time; Tissues; Tracer; X-linked intellectual disability; base; behavioral impairment; early onset; effective therapy; epileptic encephalopathies; experimental study; gamma-Aminobutyric Acid; human disease; improved; in vivo; infancy; inhibitory neuron; innovation; male; mitochondrial dysfunction; mitochondrial membrane; mortality; mouse model; neonatal mice; neuron loss; neuronal excitability; neurophysiology; novel; novel therapeutic intervention; oxidation; oxidative damage; patch clamp; postnatal; receptor; success; synaptic function; therapeutic evaluation

PROJECT ABSTRACT Epileptic encephalopathies (EEs) are severe brain disorders of early infantile and childhood age onset characterized by epileptic seizures, abnormal electroencephalogram (EEG), severe cognitive and behavioral impairments that might lead to early death. It is estimated that ~2.9 million Americans live with epilepsy and the mortality rate in people with epilepsy is ~2-3 times higher than the general population. Several genetic mutations associate with EEs including mutations in the X-linked intellectual disability gene CASK that are found in patients with Ohtahara syndrome (OS) and West Syndrome (WS). Constitutive CASK deletion in mammals is incompatible with life and the prognosis of CASK hemizygous male patients remains extremely grim. The precise function of CASK and the potential mechanisms by which CASK mutation produces EE remains obscure. Because the constitutive CASK-/- knockout mice exhibited neonatal lethality, we recently generated a novel mouse model of EE by deleting CASK specifically from the neurons (CASKNKO). We found that CASKNKO mice display severe growth retardation, recurrent tonic spasms, EEG anomalies, and myoclonus beginning postnatal day 17 that leads to death by postnatal day 25. Multiple studies have shown that CASK protein is localized at the mitochondrial membranes. Recently, CASK gene expression was found to be regulated in an NAD+/Sirtuin1 dependent manner in mouse neurons. Moreover, we found that mammalian CASK interacts and co-localizes with mitochondrial proteins, and significantly modulates mitochondrial function and number. Based on the evidences from literature and our findings we hypothesize that CASK plays a role in brain mitochondrial function and metabolism, and is critical for optimum neuronal excitability in vivo. To test this hypothesis, we will examine the brain mitochondrial, metabolic, and electrophysiological functional changes as well as synaptic excitatory/inhibitory balance in the CASKNKO mice. We will further identify the specific domain/s of CASK that interacts with mitochondrial proteins, and determine if SIRT1-dependent mitochondrial biogenesis pathway is dysregulated in the brain of CASKNKO mice. Experiments will be performed before and after the onset of myoclonus to distinguish between a potential cause and consequence relation with the disease. We will also test if pharmacological activation of NAD+/SIRT1 pathway can stimulate mitochondrial biogenesis in the brain and CASK expression in glial cells to rescue EE phenotype in the CASKNKO mice. Success in the proposed project will uncover how loss of neuronal CASK alters mitochondrial and synaptic functions to produce EE. The long-term goal of our project is to use the novel CASKNKO EE mouse model to identify potential disease biomarkers and test therapeutic strategies for clinical intervention.

项目摘要 癫痫脑病(EES)是婴幼儿和儿童期发病的严重脑部疾病。 以癫痫发作、脑电异常、严重的认知和行为为特征 可能导致早逝的损伤。据估计，约有290万美国人患有癫痫和 癫痫患者的死亡率是普通人群的2-3倍。几个基因 与EES相关的突变包括X连锁智力残疾基因桶中的突变 发现于大田原综合征(OS)和西部综合征(WS)患者。中的构成桶删除 哺乳动物与生命格格不入，木桶半合子男性患者预后极差 冷酷。CAASK基因的精确功能及其突变产生EE的可能机制 仍然鲜为人知。由于结构性木桶/基因敲除小鼠表现出新生致死性，我们最近 通过从神经元(CASKNKO)中删除特定的CASK，产生了一种新的EE小鼠模型。我们发现 CASKNKO小鼠表现出严重的生长迟缓，反复的紧张性痉挛，脑电异常，以及 从出生后第17天开始出现肌阵挛，导致出生后第25天死亡。多项研究表明 该木桶蛋白定位于线粒体膜。最近发现了CASK基因的表达 在小鼠神经元中以NAD+/Sirtuin1依赖的方式进行调控。此外，我们发现， 哺乳动物木桶与线粒体蛋白相互作用并共同定位，并显著调节 线粒体的功能和数量。基于文献证据和我们的发现，我们假设 木桶在大脑线粒体功能和新陈代谢中发挥作用，对最佳神经元至关重要 活体内兴奋性。为了验证这一假设，我们将检查大脑线粒体、代谢和 CASKNKO小鼠的电生理功能变化及突触兴奋/抑制平衡。 我们将进一步鉴定与线粒体蛋白相互作用的CASK的特定结构域/S，并确定 如果依赖SIRT1的线粒体生物发生通路在CASKNKO小鼠脑内失调。 实验将在肌阵挛发作前后进行，以区分潜在的 与疾病的因果关系。我们还将测试药物活性是否 NAD+/SIRT1通路促进脑线粒体生物发生和胶质细胞CASK表达 挽救CASKNKO小鼠的EE表型。拟议项目的成功将揭示出 神经元桶改变线粒体和突触功能以产生EE。我们项目的长期目标是 是使用新的CASKNKO EE小鼠模型来识别潜在的疾病生物标记物并测试治疗 临床干预策略。