DNA damage and repair in inflammation-induced peripheral sensitization

炎症引起的外周敏化中的 DNA 损伤和修复

• 批准号: 8870628
• 负责人: Mark R. Kelley
• 金额: $ 23.4万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8870628
• 关键词: Address; Afferent Neurons; Alkylation; Animals; Antioxidants; Area; Attenuated; Base Excision Repairs; Biological Response Modifiers; Blood Circulation; CCL2 gene; Calcitonin Gene-Related Peptide; Caliber; Cells; Chronic; Chronic inflammatory pain; Cleaved cell; DNA Damage; DNA Repair; Data; Dinoprostone; Event; Exposure to; Freund' s Adjuvant; Genes; Healed; Hypersensitivity; Immune; Immune system; Inflammation; Inflammation Mediators; Inflammatory; Injection of therapeutic agent; Injury; Ion Channel; Laboratories; Lead; Maintenance; Mechanics; Mediating; Metabolic; Neurons; Oxidation-Reduction; Pain; Pathway interactions; Peripheral; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Process; Production; Proteins; Rattus; Reactive Oxygen Species; Role; Secondary to; Signal Pathway; Signal Transduction; Site; Slice; Spinal Cord; Testing; Toxic effect; Transcriptional Activation; Trauma; base; behavior measurement; cancer therapy; chronic pain; endonuclease; healing; human APEX1 protein; immunoregulation; in vitro Model; in vivo Model; neuronal excitability; new therapeutic target; novel; novel therapeutic intervention; overexpression; oxidation; oxidative DNA damage; oxidative damage; prevent; protein expression; public health relevance; repaired; response; therapy design; tissue trauma; transcription factor

 DESCRIPTION (provided by applicant): Although inflammation-induced peripheral sensitization (i.e. increased sensitivity of sensory neurons) can resolve as an injury heals, under pathological conditions this sensitization is maintained and contributes to chronic inflammatory pain. Studies of the cellular mechanisms mediating this maintenance of peripheral sensitization have focused on transcriptional changes that alter protein expression or post-translational modulation of various proteins, especially ion channels. To date, however, these studies have not resulted in new therapeutic approaches for treating chronic inflammatory pain. For this R21 application, we propose a novel mechanism for maintaining sensitization of sensory neurons, i.e. inflammation-induced DNA damage. This damage could result in an alteration in the phenotype of neurons from "normal" to the sensitized state. Recent studies performed in our laboratory provide support for examining this mechanism, since we have shown that augmenting DNA repair mechanism reverses toxicity in sensory neurons induced by cancer therapies. Furthermore, our preliminary data suggest that inflammation and the inflammatory mediators LPS, MCP-1, and, PGE2, can produce DNA damage in sensory neurons. Thus, we hypothesize that inflammation and inflammatory mediators produce oxidative DNA damage in sensory neurons that contributes to hypersensitivity and that augmenting the base excision repair pathway protects neurons from this damage and thus attenuates the enhanced excitability. To test this hypothesis we propose two specific aims. In studies for the first aim, w will determine whether CFA-induced inflammation or long-term exposure to inflammatory mediators (LPS, MCP-1 or PGE2) in isolated sensory neurons produces reactive oxygen species (ROS) and DNA damage in sensory neurons. We also will determine whether antioxidants or increasing APE1 repair activity (by overexpressing it in sensory neurons) prevents or reverses the DNA damage. In aim 2, we will determine whether augmenting APE1 activity with overexpression in sensory neurons prevents or reverses peripheral sensitization induced by CFA injection into the rat hindpaw or by long-term exposure to inflammatory mediators (LPS, MCP-1 or PGE2) in isolated sensory neurons. If we demonstrate that DNA repair reverses peripheral sensitization that occurs during inflammation, our findings have important implications for elucidating a novel therapeutic target for treating chronic pain.

 描述（应用程序提供）：尽管炎症引起的周围传感器化（即感觉神经元的敏感性提高）可以随着损伤的愈合而解决 病理状况这种敏感性得到了维持，并导致慢性炎症性疼痛。介导这种维持外围感觉的细胞机制的研究集中在改变蛋白质表达或翻译后调节的转录变化，尤其是各种蛋白质，尤其是离子通道。然而，迄今为止，这些研究还没有引起治疗慢性炎症性疼痛的新治疗方法。对于这种R21应用，我们提出了一种保持感觉神经元灵敏度的新型机制，即炎症诱导的DNA损伤。这种损害可能导致神经元的表型从“正常”变为敏感状态。在我们的实验室中进行的最新研究为检查这种机制提供了支持，因为我们已经表明，增加DNA修复机制会逆转癌症疗法诱导的感觉神经元的毒性。此外，我们的初步数据表明，注射和炎症介质LPS，MCP-1和PGE2可以在感觉神经元中产生DNA损伤。因此，我们假设感染和炎症介质在感觉神经元中产生氧化性DNA损伤，从而有助于超敏反应，并增强基本惊喜修复途径可保护神经元免受这种损害，从而减轻增强的刺激性。为了检验这一假设，我们提出了两个具体目标。在第一个目标的研究中，W将确定孤立感觉神经元中CFA诱导的炎症或长期暴露于炎症介质（LPS，MCP-1或PGE2）是否会在感觉神经元中产生活性氧（ROS）和DNA损伤。我们还将确定抗氧化剂或增加APE1修复活性（通过在感觉神经元中过表达）是否可以防止或逆转DNA损伤。在AIM 2中，我们将确定在感官神经元中使用过度表达的APE1活性是否可以防止CFA注射到大鼠后爪中引起的外围传感化或逆转外围感应化，还是长期暴露于孤立的感觉神经元中的炎症介体（LPS，MCP-1或PGE2）。如果我们证明DNA修复会逆转注射过程中发生的外围感觉，我们的发现对于阐明一种新的热靶标的治疗慢性疼痛具有重要意义。