Understanding the Etiology of CASK Associated Epileptic Encephalopathy

了解 CASK 相关癫痫性脑病的病因

• 批准号: 10378009
• 负责人: Sarika Srivastava
• 金额: $ 40.04万
• 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/10378009
• 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; Persons; 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 癫痫性脑病 (EE) 是婴儿早期和儿童时期发病的严重脑部疾病 其特征为癫痫发作、脑电图异常、严重的认知和行为 可能导致过早死亡的损伤。据估计，约有 290 万美国人患有癫痫症 癫痫患者的死亡率比普通人群高约 2-3 倍。几个遗传 与 EE 相关的突变包括 X 连锁智力障碍基因 CASK 的突变，这些突变 发现于大田原综合征（OS）和韦斯特综合征（WS）患者。组成型 CASK 缺失 哺乳动物与生活不相容，CASK半合子男性患者的预后仍然极其严重 严峻。 CASK的精确功能以及CASK突变产生EE的潜在机制 仍然晦涩难懂。由于组成型 CASK-/- 基因敲除小鼠表现出新生儿致死性，我们最近 通过专门从神经元中删除 CASK (CASKNKO)，生成了一种新的 EE 小鼠模型。我们发现 CASKNKO 小鼠表现出严重的生长迟缓、反复性强直性痉挛、脑电图异常和 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 CASK 蛋白位于线粒体膜上。最近发现CASK基因表达 在小鼠神经元中以 NAD+/Sirtuin1 依赖性方式受到调节。此外，我们发现 哺乳动物 CASK 与线粒体蛋白相互作用并共定位，并显着调节 线粒体的功能和数量。根据文献证据和我们的研究结果，我们假设 CASK 在脑线粒体功能和新陈代谢中发挥作用，对于最佳神经元至关重要 体内的兴奋性。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以及突触兴奋/抑制平衡。 我们将进一步鉴定 CASK 与线粒体蛋白相互作用的特定结构域，并确定 CASKNKO 小鼠大脑中 SIRT1 依赖性线粒体生物发生途径是否失调。 将在肌阵挛发作之前和之后进行实验，以区分潜在的肌阵挛 与疾病的因果关系。我们还将测试是否有药理学活性 NAD+/SIRT1 通路可以刺激大脑中的线粒体生物合成和神经胶质细胞中的 CASK 表达 拯救 CASKNKO 小鼠的 EE 表型。拟议项目的成功将揭示如何损失 神经元 CASK 改变线粒体和突触功能以产生 EE。我们项目的长期目标 是使用新型 CASKNKO EE 小鼠模型来识别潜在的疾病生物标志物并测试治疗方法 临床干预策略。