Gene Therapy for Treatment of Epilepsy

描述（由申请人提供）：尽管癫痫治疗取得了许多进展，但药物干预难治性癫痫发作仍然是癫痫患者发病和残疾的重要原因。涉及癫痫患者的纵向研究表明，许多患者癫痫发作的频率和严重程度降低，但手术和药物治疗的患者往往表现出记忆功能进行性下降，尽管治疗。因此，需要新的方法来控制癫痫发作。癫痫的发作倾向增加是由异常的神经元兴奋性引起的。电压门控离子通道在控制神经元的内在兴奋性中起着重要作用，并且许多离子通道与人类和动物的癫痫综合征有关。一类这样的电压门控离子通道是超极化激活的环核苷酸门控（HCN）通道，其介导阳离子电流Ih。四个密切相关的基因（HCN 1 -4）编码不同的通道亚基蛋白（HCN 1 -4）已被确定，这些通道已牵连在全身性和局灶性癫痫。Hcn 2的整体缺失导致小鼠的失神癫痫，可能是通过增加丘脑皮质神经元中的钙通道爆发。我们最近的特点是一种新的自发的小鼠神经系统突变，冷漠，这是由于在HCN 2基因中插入四个碱基对，破坏HCN 2蛋白表达的癫痫缺席。由于丘脑皮质神经元中HCN 2的丢失产生钙通道介导的爆裂，导致小鼠的失神发作，我们假设丘脑皮质神经元中HCN 2的病毒过表达将恢复正常的h通道功能，并减少癫痫，冷漠小鼠的癫痫发作。我们将利用生理学、细胞生物学和生物化学技术来解决以下具体目标：1）确定在冷漠小鼠的丘脑皮质神经元中病毒过表达HCN 2是否可以恢复HCN 2蛋白表达并逆转Ih的缺陷，以及2）确定在丘脑皮质神经元中病毒过表达HCN 2是否减少冷漠小鼠的癫痫发作。 公共卫生相关性：在公共卫生方面，尽管有许多新的内科和外科治疗方法，但顽固性癫痫仍然是癫痫患者残疾的一个重要原因。这项工作的目的是探索基因治疗利用病毒递送特定的离子通道基因到神经元是否可以有效地逆转离子通道缺陷，并防止癫痫发作在癫痫脑，与探索这种工具作为一种新的治疗药物难治性癫痫的最终目标。

DESCRIPTION (provided by applicant): Despite numerous advances in epilepsy therapeutics, seizures refractory to medical intervention remain a significant cause of morbidity and disability in patients with epilepsy. Longitudinal studies involving patients with epilepsy have shown reduction of frequency and severity of seizures in many patients, but both surgically and medically treated patients often demonstrate a progressive decline in memory function despite treatment. As such novel approaches to controlling seizures in epilepsy are warranted. Increased seizure propensity in epilepsy is caused by abnormal neuronal excitability. Voltage gated ion channels play an important role in controlling intrinsic neuronal excitability, and many have been implicated in human and animal epilepsy syndromes. One such class of voltage-gated ion channels is the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel, which mediates the cationic current, Ih. Four closely related genes (Hcn1-4) coding for distinct channel subunit proteins (HCN1-4) have been identified; these channels have been implicated in both generalized and focal epilepsies. Global deletion of Hcn2 causes absence epilepsy in mice, likely by increasing calcium channel bursting in thalamocortical neurons. We have recently characterized a novel spontaneous mouse neurological mutant, apathetic, which has absence epilepsy owing to a four base pair insertion in the Hcn2 gene that disrupts HCN2 protein expression. Because loss of HCN2 in thalamocortical neurons produces calcium channel-mediated bursting that leads to absence seizures in mice, we hypothesize that viral overexpression of HCN2 in thalamocortical neurons will restore normal h channel function and reduce seizures in the epileptic, apathetic mice. We will utilize physiological, cell biological and biochemical techniques to address the following specific aims: 1) To determine whether viral overexpression of HCN2 in thalamocortical neurons of apathetic mice can restore HCN2 protein expression and reverse the deficit in Ih, and 2) to determine whether viral overexpression of HCN2 in thalamocortical neurons reduce seizures in apathetic mice. PUBLIC HEALTH RELEVANCE: With respect to public health, despite numerous new medical and surgical treatments, refractory seizures remain a significant cause of disability in patients with epilepsy. The purpose of this work is to explore whether gene therapy utilizing viral delivery of specific ion channel genes to neurons can effectively reverse ion channel deficits and prevent seizures in epileptic brain, with the ultimate goal of exploring this tool as a novel therapy for medically refractory epilepsy.