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（由申请人提供）：虽然炎症引起的外周敏化（即感觉神经元的敏感性增加）可以随着损伤愈合而消失，但在 然而，迄今为止，对介导这种外周敏化维持的细胞机制的研究集中在改变蛋白质表达或各种蛋白质（尤其是离子通道）的翻译后调节的转录变化上。 ，这些研究尚未产生治疗慢性炎症疼痛的新治疗方法，对于 R21 的应用，我们提出了一种维持感觉神经元敏感性的新机制，即炎症诱导的 DNA 损伤。这种损伤可能导致神经元表型从“正常”状态转变为敏化状态，我们实验室最近进行的研究为检查这种机制提供了支持，因为我们已经证明增强 DNA 修复机制可以逆转由感觉神经元引起的毒性。此外，我们的初步数据表明炎症和炎症介质 LPS、MCP-1 和 PGE2 可以在感觉神经元中产生 DNA 损伤，因此，我们研究炎症和炎症介质在感觉神经元中产生氧化性 DNA 损伤。导致过敏，增强碱基切除修复途径可以保护神经元免受这种损伤，从而减弱增强的兴奋性。为了检验这一假设，我们在第一个目标的研究中提出了两个具体目标，我们将确定 CFA 是否诱导炎症或长期。 - 分离的感觉神经元长期暴露于炎症介质（LPS、MCP-1 或 PGE2）会在感觉神经元中产生活性氧 (ROS) 和 DNA 损伤。我们还将确定是否需要抗氧化剂或增加 APE1 修复活性。 （通过在感觉神经元中过度表达）预防或逆转 DNA 损伤 在目标 2 中，我们将确定通过在感觉神经元中过度表达来增强 APE1 活性是否可以预防或逆转由 CFA 注射到大鼠后爪或长期暴露引起的外周敏化。如果我们证明 DNA 修复可以逆转炎症过程中发生的外周敏化，那么我们的发现将具有重要意义。阐明治疗慢性疼痛的新治疗靶点。