Testing the effects of a selective calpain-2 inhibitor on spontaneous recurrent seizures in mouse models of epilepsy

摘要 癫痫是继偏头痛之后最常见的神经系统疾病。当前的抗癫痫药物治疗 主要是试图减少兴奋或加强抑制，以控制癫痫发作。不幸的是，这样的 治疗会导致一些不良的副作用，并且对药物的疗效有限。 难治性癫痫病例。到目前为止，还没有开发出部分作为抗癫痫药物的治疗方法。 由于对癫痫发病过程的了解有限。它一般都是 接受高达50%的癫痫患者由于引发初始损伤而患上癫痫，例如 癫痫持续状态、中风或创伤性脑损伤。这种最初的触发损伤被认为激活了一种 一连串的事件导致进一步的癫痫发作，增加大脑损伤和自我传播。脚踝疼痛是一种 可溶性钙依赖蛋白水解酶家族，自被激活以来，与癫痫有关 通过癫痫发作和参与神经元损伤。最近的研究也表明，在早期 癫痫的发生、发作、钙蛋白酶活性和神经元损伤是相关的，治疗 使用非选择性钙蛋白酶抑制剂减少自发性复发性癫痫(SRS)的发生 匹罗卡品致痫大鼠模型的建立。我们的实验室已经证明了CalPain-1和CalPain-2这两种 大脑中的主要钙蛋白亚型在大脑中具有相反的功能。我们还发现CalPain-2 前脑兴奋性神经元Calain-2缺失的条件性基因敲除小鼠表现为正常癫痫 重复注射低剂量海人酸(KA)后的活动，但没有表现出脑部炎症， 癫痫发作后7天海马区依赖学习中的变性和认知障碍。类似 当野生型小鼠在癫痫发作后每天和连续七天接受治疗时，获得保护结果 一种选择性的钙蛋白酶-2抑制剂。这些结果有力地支持了Calain-2可能代表一种 潜在的治疗靶点，以防止癫痫发作的各种病理后果。此第一阶段STTR是 旨在首先确定选择性Calain-2抑制剂NA-184是否可以防止 在两种癫痫小鼠模型中，重复小剂量红藻氨酸(KA)或降低SRSS的频率 匹罗卡品模型(目标1)。在目标2中，我们将测试鼻腔给药NA-184对KA-1的影响。 而匹罗卡品所致的神经病理，随着各种抗癫痫药物的鼻腔给药日益增多 在临床上使用。在这项短期试验计划的第二阶段，我们会进一步发展鼻腔给药。 184作为抗癫痫治疗。NeurAegis是一家专注于开发 选择性钙蛋白酶-2抑制剂用于治疗急性神经元损伤，包括创伤性脑损伤和 反复脑震荡。这项建议旨在扩大这些Calain-2的潜在应用 通过确定它们是否也可以被开发为癫痫的潜在治疗方法来开发这些抑制剂。

Abstract Epilepsy is the most prevalent neurological diseases after migraines. Current antiepileptic drug treatments mainly attempt to reduce excitation or enhance inhibition in order to control seizures. Unfortunately, such therapeutics result in a number of undesirable side-effects, and demonstrate limited efficacy against drug- resistant cases of epilepsy. So far, no treatment has been developed as an anti-epileptogenic agent, in part because of the limited understanding of the processes involved in the development of epilepsy. It is generally accepted that up to 50% of all epileptic patients become epileptic as a result of a triggering initial injury such as status epilepticus, stroke or traumatic brain injury. This initial triggering injury has been postulated to activate a cascade of events leading to further seizures, increased brain damage and self-propagation. Calpains are a family of soluble calcium-dependent proteases, which have been implicated in epilepsy, since they are activated by seizures and participate in neuronal damage. Recent studies have also indicated that during early epileptogenesis, seizure occurrence, calpain activity and neuronal damage are correlated, and that treatment with a non-selective calpain inhibitor reduces the development of spontaneous recurrent seizures (SRS) in the pilocarpine model of epilepsy in rats. Our laboratory has demonstrated that calpain-1 and calpain-2, two of the major calpain isoforms in the brain, have opposite functions in the brain. We have also found that calpain-2 conditional knock-out mice with calpain-2 deletion in excitatory neurons from the forebrain show normal seizure activity following injections of repeated low doses of kainic acid (KA) but exhibit no brain inflammation, degeneration and cognitive impairment in hippocampus-dependent learning 7 days after seizures. Similar protective results were obtained when wild-type mice were treated daily and for seven days after seizures with a selective calpain-2 inhibitor. These results strongly support the hypothesis that calpain-2 might represent a potential therapeutic target to prevent various pathological consequences of seizures. This Phase I STTR is directed at first determining whether a selective calpain-2 inhibitor, NA-184, might prevent the appearance of SRSs or reduce their frequency in two mouse models of epilepsy, the repeated low doses of kainic acid (KA) or of pilocarpine models (Aim #1). In Aim # 2, we will test the effects of intranasal administration of NA-184 on KA- and pilocarpine-induced neuropathology, as intranasal delivery of a variety of anti-epileptic drugs is increasingly used in the clinic. In Phase II of this STTR, we will further pursue the development of intranasal delivery of NA- 184 as an anti-epileptic treatment. NeurAegis is a small biotech company focusing on the development of selective calpain-2 inhibitors for the treatment of acute neuronal injury, including traumatic brain injury and repeated concussions. This proposal is directed at expanding the potential applications of these calpain-2 inhibitors by determining whether they could also be developed as potential therapeutic treatment for epilepsy.