Saracatinib and 1400W Counteract Nerve Agents-Induced Long-Term Neurotoxicity

摘要 化学战神经毒剂（CWNA）越来越多地用于攻击世界各地的平民。沙林毒气袭击 在东京和叙利亚以及在马来西亚和英国的VX袭击证明了CWNA的真实的威胁。CWNA暴露 它在全球范围内影响人类健康，但我们缺乏对幸存者的有效治疗。直到最近，预防急性 由于接触CWNA而导致的死亡是最优先考虑的。然而，解决长期影响也至关重要 鉴于沙林毒气袭击的幸存者虽然住院接受常规治疗， 癫痫发作和认知、运动和心理障碍。像有机磷（OP）一样，CWNA是 胆碱酯酶抑制剂和有效的促神经生长剂。在动物模型中，急性CWNA或OP暴露诱导 癫痫持续状态（SE）和其他胆碱能症状。目前的医疗对策（MCM- 阿托品、肟和地西泮或咪达唑仑）不能预防长期神经毒性和合并症， 主要是由于持续的神经炎症和神经变性。我们的首要假设是 神经保护剂与MCM组合将有效地抵消NA诱导长期神经毒性 恢复大脑功能我们提出了两种新的神经保护剂：saracatinib（SAR/AZD 0530，一种Src激酶 抑制剂）和1400 W（诱导型NO合酶抑制剂）。两者都表现出显著的神经保护作用， 在慢性癫痫的红藻氨酸（KA）和DFP（梭曼替代物）大鼠模型中的疾病改善作用。两 在人类中测试了其他适应症，没有报道任何副作用。脑切片的组织学 动物模型证实测试药物显著降低神经炎症和神经变性， SE之后CWNA暴露的最常见特征。我们给两种药物（分别给药） 以及动物暴露于DFP/KA/梭曼后的MCM，以模拟“现场疏散和住院后” 场景（FOA）。正如预期的那样，单独的MCM不能预防DFP/KA诱导的神经变性、癫痫发作， 神经行为缺陷当神经保护剂作为后续治疗时，我们可以减轻 DFP/KA/梭曼诱导的脑病理学，为神经保护策略提供了概念验证 暴露在CWNA中我们将在大鼠DFP和梭曼模型中优化SAR和1400 W， 在G.猪（梭曼）和大鼠VX模型，并确定单一或两种药物的组合的功效 减轻神经病理学和行为缺陷[特定目标（SA）1-3]。我们将进行非GLP PK/PD-毒性研究，并启动预期用于人体（FOA）的药物开发（SA 4）。我们会委聘 无偏倚的长期视频EEG研究，以量化癫痫发作和癫痫样棘波，并进行MRI/PET 扫描、体视学以确定神经元损失和神经炎性细胞因子的多重测定。我们将 在不同的时间点进行一系列的行为测试。这项研究涉及反ACT使命， 也就是说，“促进和支持研究和开发新的和改进的疗法，以减轻健康 化学威胁的影响。“先导化合物将获得FDA的批准。

Abstract Chemical warfare nerve agents (CWNAs) are increasingly used to attack civilians worldwide. The sarin attacks in Tokyo and Syria and VX attack in Malaysia and England prove the real threat of CWNA. CWNA exposure impacts human health globally, but we lack effective treatment for survivors. Until recently, preventing acute death due to CWNA exposure was a top priority. However, addressing the long-term effects is also crucial given that survivors of sarin attacks, though hospitalized and treated with conventional therapy, developed seizures and cognitive, motor, and psychological impairments. Like organophosphates (OP), CWNAs are cholinesterase inhibitors and potent seizurogenics. In animal models, acute CWNA or OP exposure induces status epilepticus (SE) and other cholinergic symptoms. The current medical countermeasures (MCM- atropine, oxime, and diazepam or midazolam) do not prevent long-term neurotoxicity and comorbidity, which are primarily due to persistent neuroinflammation and neurodegeneration. Our overarching hypothesis is that neuroprotectant/s, in combination with MCM, will effectively counteract NA-induced long-term neurotoxicity and restore brain function. We propose two novel neuroprotectants; saracatinib (SAR/AZD0530, a Src kinase inhibitor) and 1400W (an inducible NO synthase inhibitor). Both demonstrated significant neuroprotective and disease-modifying effects in kainate (KA) and DFP (a soman surrogate) rat models of chronic epilepsy. Both tested in humans for other indications, and no adverse effects were reported. Histology of brain sections from animal models confirmed that the test drugs significantly reduced neuroinflammation and neurodegeneration, the most common features of CWNA exposure that follows SE. We had administered both drugs (separately) and the MCM after DFP/KA/soman exposure in animals to mimic an "after field evacuation and in-hospital" scenario (FOA). As expected, MCM alone did not prevent DFP/KA-induced neurodegeneration, seizures, and neurobehavioral deficits. When neuroprotectant was administered as a follow-on therapy, we could mitigate DFP/KA/soman-induced brain pathology, which provide the proof-of-concept for the neuroprotective strategy for a CWNA exposure scenario. We will optimize both SAR and 1400W in rat DFP and soman models and validate in G. pig (soman) and rat VX models and determine the efficacy of single or combination of both drugs in mitigating neuropathology and behavioral deficits [Specific Aims (SA) 1-3]. We will conduct non-GLP PK/PD-toxicity studies and initiate drug development (SA 4) for intended use in humans (FOA). We will employ unbiased long-term video-EEG studies to quantify seizures and epileptiform spikes, and conduct MRI/PET scan, stereology to determine neuronal loss, and multiplex assay for neuroinflammatory cytokines. We will conduct a battery of behavioral tests at various time-points. This research addresses the CounterACT mission, i.e., "to foster and support research and development of new and improved therapeutics to mitigate the health effects of chemical threats." The lead compound will move forward for FDA approval.