Cross-species modeling of epileptogenesis in KCNT1-associated epilepsy

项目摘要 癫痫是最常见的儿童神经系统疾病之一，在美国，每10万名儿童中就有40名患有癫痫。 我们清静一点.在一岁之前癫痫发作的儿童的早期死亡率增加了六倍，部分原因是 对常规抗惊厥药的反应不成比例地差。基因检测的可用性 大大改善了早发性癫痫的病因诊断，因为现在约26%的早期癫痫 与致病基因突变有关的各种基因，如离子通道。然而，准确地说- 靶向治疗选择仍然有限。KCNT 1基因的错义致病性变体， 钠激活钾通道，是约40%的严重癫痫发作病例的病因 称为婴儿癫痫伴迁移性局灶性发作（EIMFS），暗示了一种强烈的基因型-表型 关系由于EIMFS的标志是医学难治性癫痫发作，因此靶向其致病机制是治疗EIMFS的有效方法。 新的抗惊厥药物干预的机会。拟议研究的目标是确定 导致EIMFS中癫痫发作的病理生理机制，以便合理使用抗惊厥治疗。 在病程早期选择和应用。目的1阐明了细胞机制，支配一个de 从患者来源的诱导多能分化的人神经元中的novo KCNT 1功能获得性变体 干细胞（iPSC）。我们假设KCNT 1通道动力学的改变导致持续性 钾电流，损害抑制性神经元的高频放电。AIM 2结合了详细的表型分析 KCNT 1相关癫痫小鼠模型的标记中间神经元的急性切片电生理 亚群我们假设海马中间神经元将受到不同程度的影响， 功能Kcnt 1敲入变体，表现为动作电位放电减少，导致前 突触GABA释放和过度兴奋性神经元爆发。综合起来，这些研究将扩大 我们对KCNT 1突变导致肿瘤发病的细胞机制的理解， 严重的儿童癫痫，为EIMFS的精确药物疗法的发展奠定了基础。 此应用程序是一个K 08职业发展奖特雷西格特勒，医学博士，博士，儿童神经病学 Lurie儿童医院的讲师。成为离子领域的独立物理学家和科学家 通道生理学和神经遗传学，格特勒博士将致力于她的大部分博士后培训， 研究离子通道病引起的遗传性癫痫。儿科神经病学分部 儿科部门对候选人的职业发展有坚定不移的承诺，因为她 利用她的神经生理学背景，并增加了应用干细胞生物学和基因的培训， 在Alfred L.博士的指导下编辑和分型癫痫动物模型。小乔治和 詹妮弗·科尔尼

Project summary Epilepsy is among the most common childhood neurologic disorders, affecting 40 children per 100,000 in the US alone. Children with seizure onset before age one have a six-fold increase in early mortality, due in part to a disproportionately poor response to conventional anticonvulsants. The availability of genetic testing has dramatically improved etiologic diagnoses of early-onset epilepsy, as ~26% of early-life epilepsy is now associated with pathogenic genetic mutations in a variety of genes such as ion channels. Yet, precisely- targeted therapeutic options remain limited. Missense pathogenic variants in KCNT1, a gene encoding a sodium-activated potassium channel, are causative for ~ 40% of cases of a severe infantile-onset epilepsy called epilepsy of infancy with migrating focal seizures (EIMFS), suggestive of a strong genotype-phenotype relationship. As a hallmark of EIMFS is medically-refractory seizures, targeting its pathogenic mechanism is an opportunity for novel anticonvulsant intervention. The goal of the proposed studies is to define the pathophysiologic mechanisms that lead to seizures in EIMFS so that anticonvulsant therapies can be rationally chosen and applied early in the disease course. Aim 1 delineates the cellular mechanisms governing a de novo KCNT1 gain-of-function variant in human neurons differentiated from patient-derived induced pluripotent stem cells (iPSCs). We hypothesize that altered KCNT1 channel kinetics result in increased persistent potassium current, impairing high-frequency firing of inhibitory neurons. Aim 2 combines detailed phenotyping of a mouse model of KCNT1-associated epilepsy with acute slice electrophysiology of labeled interneuron subpopulations. We hypothesize that hippocampal interneurons will be differentially affected by a gain-of- function Kcnt1 knock-in variant, evidenced by decreased action potential firing, with resultant decreased pre- synaptic GABA release and excessive excitatory neuron bursting. Taken together, these studies will broaden our understanding of the cellular mechanisms by which KCNT1 mutations contribute to the pathogenesis of severe childhood epilepsy, laying the groundwork for development of precise pharmacotherapies for EIMFS. This application is for a K08 Career Development Award for Tracy Gertler, M.D., Ph.D., Child Neurology Instructor at Lurie Children’s Hospital. To become an independent physician-scientist in the fields of ion channel physiology and neurogenetics, Dr. Gertler will commit the majority of her post-medical training to research in genetic epilepsy due to ion channelopathies. The division of pediatric neurology within the pediatrics department has an unwavering commitment to the career development of the candidate as she takes advantage of her neurophysiology background and adds training in applied stem cell biology and gene- editing and phenotyping of animal models of epilepsy under the mentorship of Drs. Alfred L. George, Jr. and Jennifer Kearney.