Antagonists of CRMP2 Phosphorylation for Chemotherapy-Induced Peripheral Neuropathy

摘要 识别神经病理性疼痛的新靶点和机制是开发新靶点的关键。 用于更好的神经病理性疼痛管理的特定药物。阿片类药物的滥用和成瘾--包括 处方止痛药、海洛因和合成阿片类药物如芬太尼-是一种严重的国家危机，影响 公共卫生以及社会和经济福利。当前的阿片类药物危机需要新的方法来 慢性疼痛管理。我们的建议利用了一项独特的发现，该发现源于拉杰什博士的实验室 Khanna(亚利桑那大学)，周围神经损伤导致轴突引导上调 CRMP2与N型电压门控性钙离子(Cav2.2) 以及Nav1.7电压门控钠通道，与神经病理性疼痛的发生有关。 利用CRMP2表面的一个口袋，适合进行电子筛查，PI的实验室进行了 近30万种化合物(各种小分子和天然产物)的虚拟屏幕。几位顶尖人物 来自这个筛选的21个‘Hit’化合物已经在体外和体内实验中得到验证，提供了 对我们的硅胶预测的实验证明。预测的热门系列的物理化学特性在以下范围内 铅或“类药物”分子的范围。我们已经组建了一个不同的多学科团队来测试 假设抑制CRMP2磷酸化与钠和钙通道活性有关 减少伤害性感受器的活动最终会减轻疼痛。我们的具体目标，以量化目标为指导，是： (1)分析CRMP2磷酸化拮抗剂的能力：(I)结合CRMP2和(Ii)阻断其 CDK5的磷酸化和(III)全细胞抑制感觉神经元的钙、钠电流 在男性/女性DRG中测试较小子集的电生理学；(2)CRMP2谱 ADME的磷酸化拮抗剂的药代动力学特性和对GPCRs，激酶， 离子通道和其他已知的疼痛靶点，包括阿片受体；(3)最好的CRMP2 利用表型筛选和避免神经损伤的磷酸化拮抗剂对啮齿动物体内疗效的研究 神经病理性疼痛(SNI)模型及磷酸化CRMP2作为靶标的潜力探讨 (4)在化疗的小鼠模型中验证优化的CRMP2磷酸化拮抗剂- 诱发周围神经病变(CIPN)，并评估潜在的奖励和/或厌恶。在我们的研究结束时，我们 期望至少有一个用于优化的领导系列，目标是开发一种有选择的和有效的 CRMP2磷酸化抑制剂，用于神经病理性疼痛，副作用或成瘾潜力最小。

SUMMARY Identification of new targets and mechanisms underlying neuropathic pain is critical to developing new target- specific medications for better neuropathic pain management. The misuse of and addiction to opioids—including prescription pain relievers, heroin, and synthetic opioids such as fentanyl—is a serious national crisis that affects public health as well as social and economic welfare. The current opioid crisis requires novel approaches to chronic pain management. Our proposal leverages a unique finding, originating from the laboratory of Dr. Rajesh Khanna (University of Arizona), that peripheral nerve injury-induced upregulation of an axonal guidance phosphoprotein collapsin response mediator protein 2 (CRMP2) and the N-type voltage-gated calcium (CaV2.2) as well as the NaV1.7 voltage-gated sodium channel, correlates with the development of neuropathic pain. Leveraging a pocket on the surface of CRMP2, amenable for in silico screening, the PI’s laboratory performed a virtual screen of nearly 0.3 million compounds (diverse small molecules and natural products). Several of the top 21 ‘hit’ compounds from this screen have been validated in in vitro and in vivo experiments, providing experimental proof of our in-silico predictions. Predicted physico-chemical properties of the hit series fall within ranges of lead- or ‘drug-like’ molecules. We have assembled a diverse multidisciplinary team to test the hypothesis that inhibiting CRMP2 phosphorylation associated with sodium and calcium channel activities to decrease nociceptor activity culminates in reduced pain. Our Specific Aims, guided by quantitative goals, are: (1) to profile CRMP2 phosphorylation antagonists for their ability to: (i) bind CRMP2 and (ii) block its phosphorylation by Cdk5 and (iii) inhibit calcium and sodium currents in sensory neurons using whole-cell electrophysiology with a smaller subset being tested in male/female human DRGs; (2) profile CRMP2 phosphorylation antagonists for ADME pharmacokinetic properties and off-target effects on GPCRs, kinases, ion channels and alternative known pain targets, including opioid receptors; (3) characterize the best CRMP2 phosphorylation antagonists for in vivo efficacy in rodents using a phenotypic screen and spared nerve injury (SNI) model of neuropathic pain and explore the potential of phosphorylated CRMP2 as a marker of target engagement; (4) validate optimized CRMP2 phosphorylation antagonists in a mouse model of chemotherapy- induced peripheral neuropathy (CIPN) and assess potential reward and/or aversion. At the end of our study, we expect to have at least one lead series for optimization with the goal of developing a selective and efficacious CRMP2 phosphorylation inhibitor for neuropathic pain with minimal side effects or addiction potential.