Brain-penetrating acetylcholinesterase reactivators for several organophosphates

几种有机磷酸酯的脑穿透性乙酰胆碱酯酶再激活剂

• 批准号: 8846691
• 负责人: Janice Elaine Chambers
• 金额: $ 71.47万
• 依托单位: MISSISSIPPI STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8846691
• 关键词: Accidents; Accounting; Acetylcholinesterase; Acetylcholinesterase Inhibitors; Atropine; Attenuated; Behavior; Behavioral; Blood; Blood - brain barrier anatomy; Brain; Brain Injuries; Cerebrospinal Fluid; Cessation of life; Chemicals; Chemistry; Cholinesterase Inhibitors; Cognitive deficits; Convulsants; Development; Diazepam; Docking; Dose; Drug Kinetics; Exposure to; F2-Isoprostanes; General Population; Glial Fibrillary Acidic Protein; Goals; Health; Hepatic; In Vitro; Insecticides; Japanese Population; Laboratories; Lead; Libraries; Life; Long-Term Effects; Measures; Metabolism; Microdialysis; Mississippi; Modeling; Muscarinic Antagonists; Nerve Degeneration; Nervous System Trauma; Neurologic; Organophosphates; Outcome; Oxidative Stress; Oximes; Paraoxon; Parathion; Penetration; Peripheral; Peripheral Nervous System; Plasma Proteins; Poison; Poisoning; Protein Binding; Publishing; Rattus; Research Project Grants; Risk; Sarin; Seizures; Structure; Subway; Survivors; Synthesis Chemistry; Testing; Therapeutic Agents; Translational Research; Universities; attenuation; chemical synthesis; computational chemistry; design; dosage; efficacy testing; excitotoxicity; improved; in vivo; inorganic phosphate; lipophilicity; molecular dynamics; nerve agent; neuron apoptosis; neuropathology; neuroprotection; novel; novel therapeutics; organophosphate poisoning; prevent; research study; screening; toxic organophosphate insecticide exposure

DESCRIPTION (provided by applicant): Organophosphate (OP) anticholinesterases, e.g., nerve agents or insecticides, are potent acetylcholinesterase (AChE) inhibitors. High dose poisoning causes excitotoxicity that leads to seizures and subsequently brain damage. The current therapy in the US includes an oxime reactivator, 2-PAM, which has little, if any, ability t cross the blood-brain barrier (BBB) and consequently cannot stop seizures and prevent brain damage. Our laboratories have developed a library of phenoxyalkyl pyridinium oximes designed to have greater lipophilicity than 2-PAM. Through a paradigm using high sub-lethal dosages of highly relevant surrogates for sarin or VX in rats and administering the novel oximes at 1 hr after OP compound treatment when seizure behavior was on- going, we have demonstrated the ability of a number of these oximes to penetrate the BBB, reactivate AChE, and to attenuate seizure behavior. The objective of this application is to further characterize a limited number of these novel oximes (initially 6, then down-selected to 3) to ultimately select a single lead oxime for an IND application. Additionally we will expand the OP chemistries tested to include an insecticidal chemistry, paraoxon (the active metabolite of parathion; tested first to avoid any confounders that could occur because of the need for bioactivation) and parathion. Endpoints of characterization include brain and peripheral AChE reactivation, seizure attenuation, neurodegeneration (glial fibrillary acidic protein accumulation), oxidative stress (F2-isoprostanes), neuropathology (apoptosis, neuron survival), and behavior. Concurrently molecular dynamics computations will determine if one or two additional oxime structures are predicted to have greater efficacy than our current selections; if so, it/they will be synthesized and substituted for our current selections. The specific aims of the proposed project are: 1. In vivo efficacy characterization aim: To provide expanded measures of neuroprotection on our currently identified BBB-penetrating oximes using the sarin and VX surrogates and also a common insecticidal OP chemistry (i.e., diethyl phosphate) using parathion and its active metabolite paraoxon. Efficacy endpoints for the 4 OP's include: 1a, efficacy screening endpoints with 6 oximes: reactivating rat brain AChE, and the attenuation of seizure behavior and neurodegeneration; and 1b, detailed efficacy characterization endpoints with 3 down-selected oximes: oxidative stress in the brain, neuropathology and behavioral deficits. 2. Pharmacokinetic aim: To determine for the 3 down-selected oximes hepatic in vitro metabolism, plasma protein binding and levels of oxime in the blood and cerebrospinal fluid (obtained through microdialysis). 3. Computational chemistry aim: To model the docking of oxime with AChE and BBB penetration to suggest improved oxime structures. 4. Chemical synthesis aim: To produce sufficient quantities of the test OP's and the test oximes for the experiments proposed, as well as the synthesis of a few new oximes if suggested by the computational chemistry aim. The ultimate outcome will be the identification of the most efficacious novel oxime for further development as a potential substitute for current therapy.

描述（由申请人提供）：有机磷酸盐（OP）抗胆碱酯酶，例如神经剂或杀虫剂，是有效的乙酰胆碱酯酶（ACHE）抑制剂。高剂量中毒会导致兴奋性，从而导致癫痫发作并随后脑损伤。当前在美国的疗法包括一个氧电反应剂2-PAM，该疗法几乎没有能力越过血脑屏障（BBB），因此无法阻止癫痫发作并防止脑损伤。我们的实验室已经开发了一个苯氧基烷基吡啶量含量的库，该图书馆旨在比2-PAM更大的亲脂性。通过使用高度相关的替代物的高度亚致死剂量，用于大鼠的沙林或VX的范式，并在1小时后1小时内给予新型氧气 当癫痫发作行为发生时，我们已经证明了许多这样的氧气渗透BBB，重新激活ACHE并减轻癫痫发作行为的能力。该应用的目的是进一步表征有限数量的这些新颖的氧气（最初6，然后下降至3），以最终为IND应用选择单个铅氧电。此外，我们将扩展所测试的OP化学成分，包括杀虫化学，二氧氧化剂（Parathion的主动代谢物；首先测试以避免由于需要生物活化而发生的任何混杂因素）和PARATHION。表征的终点包括大脑和周围疼痛激活，癫痫发作衰减，神经退行性（神经纤维纤维酸性蛋白的积累），氧化应激（F2-异丙烷），神经病理学（凋亡，神经元存活）和行为。同时，分子动力学计算将确定是否预计一两个其他的摄氏结构具有比我们当前选择更大的疗效。如果是这样，它将合成并替换为我们当前的选择。拟议项目的具体目的是：1。体内功效特征的目的：使用Sarin和VX代理，对我们当前确定的BBB渗透氧化物进行扩展的神经保护措施，以及使用Parathion和Activation Active paraoxoxoxoxoxoxoxoxoxoxon和Active paraoxoxon。 4 OP的功效终点包括：1A，具有6个含量的功效筛选终点：重新激活大鼠脑疼痛以及癫痫发作行为和神经变性的衰减；和1B，详细的功效表征终点，带有3种下降的氧气：大脑中的氧化应激，神经病理学和行为缺陷。 2。药代动力学的目的：确定3种下降的氧化型肝内代谢，血浆蛋白结合以及血液和脑脊液中的氧电水平（通过微透析获得）。 3。计算化学的目的：对氧电的对接建模与ACHE和BBB穿透性的对接，以提示改善的甲电结构。 4。化学合成的目的：为提出的实验产生足够数量的测试OP和测试含量，以及如果计算化学的目的提出了一些新的氧气的合成。最终的结果将是确定最有效的新型牛油，以进一步发展，作为当前治疗的潜在替代品。