Alternatives to Opioids for Chronic Pain: Part IV

描述（由申请人提供）：神经性疼痛是普遍的，持续的，并使人虚弱。对于神经性疼痛综合征，目前还没有一种没有副作用的有效治疗方法。据估计，美国有500万患者患有神经性疼痛综合征，包括糖尿病患者、艾滋病患者、老年人和经历过创伤的年轻人。在这个修订后的竞争性更新提案中，我们应用先前资助期的数据来研究以下假设：周围神经损伤通过小胶质toll样受体4（TLR4）和CD14的表达激活中枢先天免疫，导致星形胶质细胞激活和趋化因子的表达，进而表现为持续的神经性疼痛。小胶质细胞在启动级联反应中起主要作用，而星形胶质细胞提供胶质到神经元的信号来维持疼痛状态。我们的工作最近的三个重要发现为当前的建议提供了指导：1)在神经损伤后的腰椎脊髓中观察到强烈的共刺激分子B7.2表达，而不是B7.1。这些数据提示周围神经损伤后CMS的保护性自身免疫的作用。2)支持先天免疫在神经性疼痛中的作用的证据，即TLR4的参与。3)数据显示一种趋化因子单核细胞趋化蛋白(MCP)-1在神经损伤诱导的异常性疼痛中起关键作用。我们的实验室将使用既定的方法来验证中心假设，以研究以下具体目标：1)评估辅助分子CD14和MD-2在神经损伤后小胶质TLR4反应中的作用。2)确定TLR4和CD14是否导致脊髓趋化因子的表达。3)确定神经胶质来源的趋化因子MCP-1在神经损伤后导致行为超敏反应的白细胞运输中的关键调节作用。转基因小鼠、反义ODN、中和抗体、免疫组织化学、RT-PCR、Western Blot分析、FACs和伤害性行为分析将用于解决这些特定目标。这些多学科研究的结果可能最终形成新的药典，以治疗和预防慢性神经性疼痛，因此具有很高的临床影响潜力。

DESCRIPTION (provided by applicant): Neuropathic pain is prevalent, persistent, and debilitating. There is no effective treatment without untoward side effects for the neuropathic pain syndromes that afflict an estimated 5 million patients in the U.S. including patients with diabetes, HIV, the elderly, and young people who experience trauma. In this revised competitive renewal proposal, we apply data from the previous funding period to investigate the following hypothesis: Peripheral nerve injury activates central innate immunity via microglial Toll-like receptor 4(TLR4) and CD14 expression that leads to astrocytic activation and chemokine expression which in turn manifests as persistent neuropathic pain. Microglia play a major role in initiating the cascade while astrocytes provide the glia-to-neuron signal to maintain pain states. Three important recent findings from our work direct this current proposal: 1) Intense co-stimulatory molecule B7.2 expression but not B7.1 was observed in the lumbar spinal cord following nerve injury. These data suggest a role of protective CMS autoimmunity following peripheral nerve injury. 2) Evidence supporting the role of innate immunity in neuropathic pain, i.e. involvement of TLR4. 3) Data to demonstrate a key role of one chemokine, monocyte chemoattractact protein (MCP)-1 in nerve injury-induced allodynia. The central hypothesis will be tested by using established methods in our laboratory to investigate the following Specific Aims: 1) Assess the role of accessory molecules CD14 and MD-2 in the microglial TLR4 responses after nerve injury. 2) Determine whether TLR4 and CD14 result in spinal chemokine expression. 3) Determine the role of the glial-derived chemokine, MCP-1 as a critical regulator of leukocyte trafficking following nerve injury that results in behavioral hypersensitivity. Genetically altered mice, antisense ODN, neutralizing antibodies, immunohistochemistry, RT-PCR, Western Blot analysis, FACs and nociceptive behavioral assays will be used to resolve these specific aims. The results from these multidisciplinary studies may culminate in novel pharmacopeia to treat and prevent chronic neuropathic pain and thus, has the potential for high clinical impact.