SUDEP Research Alliance: iPSC and Mouse Neurocardiac Models, Application 6 of 7

SUDEP 研究联盟：iPSC 和小鼠神经心脏模型，应用 6 of 7

• 批准号: 8819852
• 负责人: Lori L. Isom
• 金额: $ 65.79万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-30 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8819852
• 关键词: Action Potentials; Affect; Alleles; Applications Grants; Arrhythmia; Ataxia; Autonomic Dysfunction; Biological Markers; Bradycardia; Brain; Cardiac; Cardiac Myocytes; Cell model; Cells; Cessation of life; Childhood; Clinical; Clinical Data; Complement; Congenital Heart Defects; Data; EKG P Wave; Electrocardiogram; Electroencephalography; Encephalopathies; Epilepsy; Etiology; Event; Fibroblasts; Frequencies; Functional disorder; Genes; Genetic; Goals; Heart; Human; Hyperactive behavior; Incidence; Inherited; Inpatients; Ions; Knock-in Mouse; Knockout Mice; Lead; Link; Maps; Measures; Methods; Modeling; Molecular; Mus; Mutation; Neurons; Nodal; Optics; Patients; Peripheral; Peripheral Nerves; Phenotype; Premature Mortality; Property; Prosencephalon; Ranvier' s Nodes; Refractory; Research; Risk; Role; SCN1A protein; Sampling; Seizures; Spinal Ganglia; Structure; Sudden Death; Syndrome; Techniques; Testing; Time; Vagus nerve structure; Ventricular; Ventricular Arrhythmia; Work; base; density; experience; follow-up; heart cell; heart rate variability; heart rhythm; high risk; in vivo; induced pluripotent stem cell; insight; loss of function; mortality; mouse model; mutant; nerve supply; neuronal excitability; postnatal; prevent; public health relevance; relating to nervous system; research study; respiratory; voltage

 DESCRIPTION (provided by applicant): Application 6 of this SUDEP Research Alliance Centers Without Walls (CWOW) grant proposal, "iPSC and Mouse Neurocardiac Models," explores cardiac arrhythmia and autonomic dysfunction as potential causes of SUDEP. Although SUDEP is the most devastating consequence of epilepsy and the leading cause of epilepsy mortality, astonishingly little is understood about its causes and no biomarkers exist to identify at risk epilepsy patients. To advance our understanding of these critical issues, we will focus on Dravet Syndrome (DS), a severe childhood epileptic encephalopathy associated with a high SUDEP incidence. DS is most frequently caused by mutations in the voltage-gated Na+ channel (VGSC) gene SCN1A, encoding NaV1.1. As NaV1.1 is expressed in brain, heart, and peripheral nerves, a compelling idea is that altered Na+ currents (INa) in DS cardiac myocytes (CMs) or autonomic neurons, in addition to central neurons, lead to arrhythmias and SUDEP. We used the induced pluripotent stem cell (iPSC) method to derive central and peripheral neurons and CMs from fibroblasts of DS subjects. Preliminary data from DS patient CMs suggest that a subset of DS subjects shows abnormal CM INa and excitability. In studies of a DS human mutant SCN1A knock-in mouse model, we observed spontaneous seizures and SUDEP, increased ventricular CM INa density, and ventricular arrhythmias at the time of SUDEP. Similarly, we found increased ventricular CM INa density, spontaneous seizures and SUDEP in a Scn1b null DS mouse model. Our work, studies of Scn1a heterozygous null DS mice, and clinical ECG studies in DS also show altered cardiac autonomic function. Thus, we hypothesize that SUDEP in DS is caused by VGSC mutations that produce cardiac electrical and/or autonomic dysfunction, in addition to brain dysfunction. Furthermore, that combined insights from studies of DS patient-derived cells, mouse models and patient peri-ictal ECG data will yield biomarkers of SUDEP risk in DS. Four specific aims will test these hypotheses: 1) To understand the effects of DS-linked SCN1A mutations on cardiac excitability using DS patient iPSC-derived CMs and DS mice; 2) To determine how DS-linked SCN1A mutations influence the excitability of autonomic neurons, cardiac autonomic innervation, and autonomic control of cardiac function using DS patient iPSC-derived autonomic neurons and DS mice; 3) To investigate changes in autonomic excitability in a second mouse model of DS, Scn1b null mice, and in SCN1B-DS patient iPSC CMs and neurons; and 4) To determine whether cardiac electrical and/or autonomic function is altered in DS patients at baseline or peri-ictally. Our wor will synergize with the entire CWOW proposal to not only uncover SUDEP mechanisms in DS, but also to provide advances in understanding SUDEP causes and biomarkers that will be applicable to other refractory epilepsies due to ion channelopathies and perhaps other etiologies. This work will also show proof-of-principle for the use of multiple platforms (cellular and clinical data from the same patients, and multiple mouse models) to individualize SUDEP risk and develop patient-specific preventative treatments.

 描述（由应用程序提供）：该SUDEP研究联盟中心的应用6（CWOW）授予建议“ IPSC和小鼠神经心动模型”，探索心律不齐和自主神经功能障碍，作为SUDEP的潜在原因。尽管SUDEP是癫痫和癫痫死亡率的主要原因的最毁灭性后果，但对其原因几乎没有理解，并且没有生物标志物的存在，无法识别处于危险的癫痫患者。为了促进我们对这些关键问题的理解，我们将专注于Dravet综合征（DS），这是与高SUDEP事件相关的严重童年癫痫性脑病。 DS最常见的是由编码NAV1.1的电压门控Na+通道（VGSC）基因SCN1A引起的。由于NAV1.1在大脑，心脏和周围神经中表达，但令人信服的想法是，除了中枢神经元外，DS心肌细胞（CMS）或自主神经元中的Na+电流（INA）改变，导致心律失常和SUDEP。我们使用诱导的多能干细胞（IPSC）方法来从DS受试者的成纤维细胞中得出中心神经元和CMS。 DS患者CMS的初步数据表明，DS受试者的子集显示出异常的CM INA和兴奋性。在对DS人突变体SCN1A敲入小鼠模型的研究中，我们观察到赞助和SUDEP，增加心室CM INA密度以及SUDEP时心律不齐。同样，我们发现在SCN1B NULL DS小鼠模型中发现心室密度，赞助和SUDEP增加。我们的工作，对SCN1A杂合无效DS小鼠的研究以及DS中的临床ECG研究也显示出心脏自主神经功能的改变。这就是我们假设DS中的SUDEP是由VGSC突变引起的，这些突变除了脑功能障碍外产生心脏电气和/或自主功能障碍。此外，从DS患者衍生的细胞，小鼠模型和患者ECG数据研究的研究结合了洞察力将产生DS中SUDEP风险的生物标志物。四个具体目标将检验以下假设：1）使用DS患者IPSC衍生的CMS和DS小鼠了解与DS连接的SCN1A突变对心脏兴奋性的影响； 2）确定使用DS患者IPSC衍生的自主神经元和DS小鼠对心脏功能的自主神经元，心脏自主神经神经的兴奋，心脏自主神经神经和心脏功能的兴奋性； 3）研究第二个小鼠模型，SCN1B无效小鼠以及SCN1B-DS患者IPSC CMS和神经元中的自主神经兴奋的变化； 4）确定在基线或周围的DS患者中，心脏电气和/或自主功能是否会改变。我们的目标将与整个CWOW提案协同作用，不仅要揭示DS中的SUDEP机制，而且还提供了理解SUDEP原因和生物标志物的进步，这些原因和生物标志物将适用于由于离子通道病和其他病情而引起的其他难治性癫痫。这项工作还将显示用于使用多个平台（蜂窝）的原理证明 来自同一患者的临床数据以及多个小鼠模型），以个性化SUDEP风险并发展患者特定的预防性治疗。