Alternatives to Opioids for Chronic Pain: Part IV

描述(由申请人提供)：神经性疼痛普遍存在，持续存在，使人虚弱。据估计，美国有500万患者患有神经病理性疼痛综合征，其中包括糖尿病患者、艾滋病病毒携带者、老年人和经历创伤的年轻人，目前没有有效的治疗方法，而不会出现副作用。在这一修订的竞争性更新方案中，我们应用前一个资金时期的数据来研究以下假设：周围神经损伤通过小胶质细胞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表达，进而表现为持续性神经病理性疼痛。小胶质细胞在启动级联反应中起主要作用，而星形胶质细胞则提供胶质细胞到神经元的信号来维持疼痛状态。我们工作中的三个重要最新发现指导了这一当前的提议：1)在神经损伤后的腰髓中观察到强烈的共刺激分子B7.2的表达，而不是B7.1的表达。这些数据提示周围神经损伤后CMS自身免疫的保护性作用。2)支持先天免疫在神经病理性疼痛中的作用的证据，即TLR4的参与。3)单核细胞趋化蛋白(MCP)-1在神经损伤性痛觉异常中的关键作用。中心假说将通过本实验室建立的方法进行验证，以研究以下具体目的：1)评估辅助分子CD14和MD-2在神经损伤后小胶质细胞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)确定神经损伤后导致行为过敏的神经损伤后，神经胶质源性趋化因子MCP-1作为白细胞运输的关键调节因子的作用。转基因小鼠、反义ODN、中和抗体、免疫组织化学、RT-PCR、Western Blot分析、流式细胞术和伤害性行为分析将被用于解决这些特定的目标。这些多学科研究的结果可能最终形成治疗和预防慢性神经病理性疼痛的新药典，因此具有很高的临床影响。

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.