Exploring the role of ATP1A3 mutations in sudden unexplained death in epilepsy

探索 ATP1A3 突变在癫痫不明原因猝死中的作用

• 批准号: 10688211
• 负责人: Andrew P. Landstrom
• 金额: $ 68.94万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-22 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10688211
• 关键词: 3-Dimensional; ATP1A3 gene; Acceleration; Action Potentials; Acute; Affinity; Agonist; Arrhythmia; Binding; Biological Models; Bradycardia; Brain; Calcium; Calcium Signaling; Cardiac; Cardiac Myocytes; Cardiovascular Physiology; Catalytic Domain; Cause of Death; Cessation of life; Child; Childhood; Complex; Development; Disease; Dysautonomias; Dystonia; Electrocardiogram; Electrophysiology (science); Epilepsy; Etiology; Exhibits; Experimental Models; Generations; Goals; Health; Heart; Heart Abnormalities; Heart Rate; Homeostasis; Human; In Vitro; K ATPase; Knock-in Mouse; Maps; Measurement; Measures; Mediating; Modeling; Molecular Target; Monitor; Morbidity - disease rate; Mus; Mutation; Myocardium; Na(+)-K(+)-Exchanging ATPase; Neurologic; Optics; Ouabain; Outcome; Paralysed; Pathologic; Patients; Pharmacotherapy; Predisposition; Prevalence; Prevention; Pump; Recording of previous events; Risk Factors; Role; Seizures; Site; Sudden Death; Telemetry; Testing; Time; Tissue Model; Tissues; Variant; Ventricular Arrhythmia; Ventricular Fibrillation; alternating hemiplegia; chronotropic; clinical translation; comparison control; extracellular; genetic variant; human model; in vitro Model; in vivo; induced pluripotent stem cell; inhibitor; innovation; insight; molecular drug target; mouse model; novel; patch clamp; pharmacologic; prevent; uptake

PROJECT SUMMARY/ABSTRACT Sudden unexplained death in epilepsy (SUDEP) is the sudden and unexplained death of a patient with a history of seizures and epilepsy who is in a reasonable state of health. It is a major cause of death in patients with epilepsy and a common cause of neurologic death overall. Believed to be caused by a culmination of cardiac and neurologic factors, epilepsy induced bradycardia is a risk factor for SUDEP and may trigger lethal ventricular arrhythmias in susceptible myocardium. Development of a robust experimental model which recapitulates this would open the door for foundational studies to develop critical pharmacotherapies. SUDEP is a tragic outcome in patients with alternating hemiplegia of childhood (AHC) which is characterized by epilepsy, dystonia, paralysis, and, notably, sudden death in the setting of bradycardia. Among AHC patients, 90% harbor underlying pathologic genetic variants in the ATP1A3-encoded alpha-3 catalytic subunit of the Na/K ATPase pump (ATP1A3). We have identified a strong correlation between the most common AHC-associated ATP1A3 variant (D801N) and short QT on ECG and ventricular fibrillation during bradycardia. Human induced pluripotent stem cell-derived cardiac myocytes from an ATP1A3-D801N-positive child (hiPSC-CMD801N) demonstrate shortened repolarization time, disrupted calcium homeostasis, and delayed-after depolarizations, which are triggers for arrhythmias. Knock-in mice hosting the D801N variant (Atp1a3D801N) have seizures, bradycardia, and sudden death. Further, Atp1a3D801N mice have a predisposition to ventricular arrhythmias, particularly at lower heart rates, compared to controls. Collectively, these findings raise the possibility that disruption of ATP1A3 in the heart underlies SUDEP in AHC patients through bradycardia-triggered arrhythmias. We hypothesize that D801N reduces pump function leading to shortened repolarization time and predisposes to lethal ventricular arrhythmias. Our goal is to use AHC as a model to establish the role ATP1A3 in the heart, determine the mechanism of SUDEP, and explore the proarrhythmic effect of bradycardia. To approach this in an innovative and rigorous way, we will utilize patient-derived hiPSCD801N- and murine Atp1a3D801N-based models for in vitro, ex vivo, and in vivo studies to determine the mechanism of arrhythmia predisposition in the heart. Specifically, we propose to determine 1) the mechanism of action potential duration shortening induced by D801N in cardiac myocytes, 2) the mechanism of cardiac arrhythmogenesis induced by D801N in 3D tissue models and ex vivo analysis, and 3) whether bradycardia due to seizures is an arrhythmogenic trigger for a “vulnerable” myocardium in Atp1a3D801N mice. In accomplishing these aims and overall goal, we will determine the function of ATP1A3 in cardiovascular physiology and its role in cardiac repolarization, calcium signaling, and ventricular arrhythmias, thus identifying molecular targets for pharmacotherapy. Finally, this will develop robust and rigorous models to determine the mechanisms of sudden death in AHC and will provide insights into mechanisms of SUDEP more broadly.

项目概要/摘要 癫痫性猝死（SUDEP）是指有癫痫病史的患者突然且不明原因死亡 健康状况良好的癫痫患者是癫痫患者的主要原因，也是常见的死亡原因。 总体而言，神经系统死亡的原因被认为是由心脏病和神经系统因素癫痫引起的。 诱发的心动过缓是 SUDEP 的危险因素，并可能在易感心肌中引发致命的室性心律失常。 开发一个稳健的实验模型来概括这一点将为基础研究打开大门 开发关键的药物疗法对于儿童交替性偏瘫 (AHC) 患者来说是一个悲惨的结果。 其特征是癫痫、肌张力障碍、瘫痪，以及显着的心动过缓猝死。 AHC 患者中，90% 在 ATP1A3 编码的 α-3 催化亚基中存在潜在的病理性遗传变异。 我们发现最常见的 AHC 相关蛋白之间存在很强的相关性。 人诱导多能性心动过缓期间心电图和心室颤动的 ATP1A3 变异 (D801N) 和短 QT。 来自 ATP1A3-D801N 阳性儿童 (hiPSC-CMD801N) 的干细胞来源的心肌细胞显示缩短 复极时间、钙稳态紊乱和除极后延迟，这些都是心律失常的触发因素。 携带 D801N 变体 (Atp1a3D801N) 的敲入小鼠会出现癫痫、心动过缓和猝死。 总体而言，与对照组相比，小鼠容易发生室性心律失常，特别是在心率较低的情况下。 这些发现提出了这样一种可能性：心脏中 ATP1A3 的破坏是 AHC 患者 SUDEP 的基础 我们认为 D801N 会降低泵功能，导致复极时间缩短。 我们的目标是使用 AHC 作为模型来确定 ATP1A3 在其中的作用。 确定 SUDEP 的机制，并探索心动过缓的致心律失常作用。 我们将采用创新且严格的方法，利用源自患者的 hiPSCD801N 和基于小鼠 Atp1a3D801N 的模型进行 具体来说，我们进行了体外、离体和体内研究，以确定心脏心律失常易感性的机制。 建议确定 1) D801N 在心肌细胞中诱导动作电位持续时间缩短的机制，2) D801N 在 3D 组织模型和离体分析中诱导心律失常的机制，以及 3) 是否 癫痫发作引起的心动过缓是 Atp1a3D801N 小鼠“脆弱”心肌的致心律失常触发因素。 实现这些目标和总体目标，我们将确定 ATP1A3 在心血管生理学中的功能及其 在心脏复极、钙信号传导和室性心律失常中的作用，从而确定其分子靶点 最后，这将开发强大而严格的模型来确定猝死的机制。 AHC 将为更广泛地了解 SUDEP 机制提供见解。

项目成果

Induced Pluripotent Stem Cell-Based Modeling of Single-Ventricle Congenital Heart Diseases.

基于诱导多能干细胞的单心室先天性心脏病模型。

• 发表时间: 2023-05
• 影响因子: 3.7
• 作者: Parker, Lauren E;Kurzlechner, Leonie M;Landstrom, Andrew P
• 通讯作者: Landstrom, Andrew P