Treatment for neuropathic pain targeting selective inhibition of MEK

描述(申请人提供)：由慢性炎症和神经系统损伤引起的神经病理性疼痛是目前可用的drg医疗设备特别难以治疗的。与神经性疼痛相关的治疗每年给社会造成的额外财政成本估计为160亿美元，收入损失和相关的无法估量的人类痛苦要多得多。显然需要一种新的基于机制的治疗神经病理性疼痛的方法。丝裂原活化蛋白激酶(MAPK)是细胞内信号转导分子，在细胞外事件对细胞反应的转导中起着关键作用。有报道称，背根神经节(DRG)中的ERK1/2及其上游MAPK激酶(MEK1/2)在介导神经病理性疼痛损伤的信号级联中发挥作用。我们希望验证这样的工作假设：选择性抑制背根神经节中的MEK1/2将抑制神经病理性疼痛。通过三个特定的目标，我们建议研究小分子和表达显性-阴性MEK1的病毒载体对MEK1/2的抑制作用，作为一种基于机制的治疗神经病理性疼痛。这项研究包括评估Qercetin的抗伤害性作用，Quercetin是一种小分子黄酮醇化合物，通过与与ATP结合口袋重叠的MEK区域结合来抑制MEK1/2，进一步高通量寻找其他具有抗伤害性特性的新型小分子MEK1/2抑制剂，通过电子对接引导理性化学修饰小分子，以及使用AAV2/8-dN-MEK1选择性地抑制DRG中的这一信号转导。我们使用最先进的行为学方法在体内分析了三种啮齿动物疼痛模型的有效性，这些模型具有强烈的炎症性(爪垫福尔马林注射)、神经性(备用神经损伤)或混合(慢性缩窄性损伤)病因。将采用传统的疼痛评估方法(热痛觉过敏和机械性痛觉过敏)以及自发疼痛的行为分析方法(负重测试和条件性位置偏爱)。提出了用结合自由能作为配体亲和力的衡量指标，对黄酮醇铅分子进行合理的化学修饰，使其在配体的电子对接中被广泛应用为MEK。研究团队由在神经科学/疼痛研究、疼痛行为分析和化学合成方面拥有专业知识的高级研究人员组成，共同提供执行该项目所需的所有技能。

DESCRIPTION (provided by applicant): Neuropathic pain resulting from chronic inflammation and injury to the nervous system is particularly difficult to treat with the currently available drg armamentarium. Annual excess financial cost to the society resulting from neuropathic pain-related treatment is estimated to be $16 billion with much more in terms of lost revenue and associated immeasurable human suffering. A novel mechanism-based treatment for neuropathic pain is clearly needed. Mitogen activated protein kinases (MAPK) are intracellular signal transducing molecules that play a critical role in transducing extracellular events to cellular responses. ERK1/2 and its upstream MAPK kinases (MEK1/2) in the dorsal root ganglion (DRG) have been reported to play a role in the signaling cascade mediating injury to neuropathic pain. We wish to test the working hypothesis that: Selective inhibition of MEK1/2 in the dorsal root ganglion will suppress neuropathic pain. Through 3 specific aims, we propose to investigate inhibition of MEK1/2 by small molecules and a viral vector expressing a dominant-negative MEK1 as a mechanism-based treatment for neuropathic pain. The study involves assessment of anti-nociceptive effects of quercetin, a small molecule flavonol compound found to inhibit MEK1/2 by binding to a region of MEK overlapping the ATP- binding pocket, further high throughput search for other novel small molecule MEK1/2 inhibitor with anti-nociceptive properties, modification of the small molecule through in silico docking-guided rational chemistry, and the use of AAV2/8-DN-MEK1 to selectively inhibit this signaling in the DRG. We employ state of art behavioral methods for in vivo analysis of effectiveness against three rodent pain models with a strong inflammatory (paw pad formalin injection), neuropathic (spared nerve injury), or mixed (chronic constriction injury) etiology. Traditional assessment of pain (thermal hyperalgesia and mechanical allodynia) as well as behavioral assays for spontaneous pain (weight bearing test and conditional place preference) will be employed. Rational chemical modification of a lead flavonol molecule with extensive use of in silico docking of ligands to MEK guided by the free-energy of binding as a measure of ligand affinity is proposed. The research team consists of senior investigators with expertise in neuroscience/pain research, behavior assay of pain, and chemical synthesis, together providing all the necessary skills to execute this project.