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

摘要 化学战神经毒剂(CWNAs)越来越多地被用于袭击世界各地的平民。沙林袭击 东京和叙利亚的VX袭击以及马来西亚和英国的VX袭击证明了CWNA的真正威胁。CWNA曝光 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，预防急性呼吸道感染 因接触CWNA而死亡是头等大事。然而，解决长期影响也是至关重要的 鉴于沙林袭击的幸存者虽然住院并接受常规治疗，但患上了 癫痫发作以及认知、运动和心理障碍。与有机磷(OP)一样，CWNA也是 胆碱酯酶抑制剂和强效致痫药。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。当前的医学对策(MCM- 阿托品、肟和安定或咪达唑仑)不能预防长期的神经毒性和合并症， 主要是由于持续性的神经炎症和神经变性。我们最重要的假设是 该神经保护剂/S与MCM联合使用将有效地对抗NA诱导的长期神经毒性 恢复大脑功能。我们提出了两种新的神经保护剂：Saracatinib(SAR/AZD0530，一种Src激酶 抑制剂)和1400W(一种诱导型一氧化氮合酶抑制剂)。两者都显示出显著的神经保护作用和 红藻氨酸(KA)和DFP(梭曼替代品)慢性癫痫大鼠模型的疾病改善作用。两者都有 在人体上进行了其他适应症的测试，没有不良反应的报告。中国人脑组织切片的组织学研究 动物模型证实，测试药物显著减少了神经炎症和神经退行性变， 紧随SE之后的CWNA暴露的最常见特征。我们分别服用了这两种药物。 以及在动物体内暴露DFP/KA/Soman后的MCM，以模拟“野战疏散和住院后” 情景(FOA)。正如预期的那样，MCM本身并不能预防DFP/KA诱导的神经变性、癫痫发作和 神经行为缺陷。当神经保护剂作为后续治疗时，我们可以缓解 DFP/KA/Soman诱导的脑病理，为神经保护策略提供概念验证 对于CWNA的暴露场景。我们将在大鼠DFP和梭曼模型上优化SAR和1400W，并 在猪(梭曼)和大鼠VX模型中验证并确定两种药物单独或联合的疗效 在减轻神经病理和行为缺陷方面[特定目标(SA)1-3]。我们将进行非GLP PK/PD-毒性研究和启动用于人类的药物开发(SA 4)(FOA)。我们将聘用 无偏见的长期视频-脑电研究，以量化癫痫发作和癫痫样棘波，并进行MRI/PET 扫描，体视学，以确定神经元丢失，和神经炎性细胞因子的多重分析。我们会 在不同的时间点进行一系列的行为测试。这项研究针对的是对抗任务， 即“促进和支持新的和改进的治疗方法的研究和开发，以减轻 化学威胁的影响。“该先导化合物将推进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.