AIBP and regulation of neuropathic pain

AIBP 和神经性疼痛的调节

• 批准号: 9816541
• 负责人: Yury Miller
• 金额: $ 78.73万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9816541
• 关键词: Acute; Affect; Affinity; Agonist; American; Apolipoprotein A-I; Arthritis; Binding; Binding Proteins; Cell membrane; Cellular Membrane; Cholesterol; Cisplatin; Development; Diabetes Mellitus; Dimerization; Event; Excision; HIV; Inflammatory; Inflammatory Response; Intrathecal Injections; Knock-out; Lead; Ligands; Mediating; Membrane Microdomains; Microglia; Molecular; Mus; Mutate; Neuroglia; Pattern; Persistent pain; Quality of life; Receptor Inhibition; Recombinants; Regulation; Role; Signal Transduction; Sphingomyelins; Spinal Cord; TLR4 gene; Tactile; Testing; Therapeutic; Variant; Work; allodynia; base; chemotherapy; experimental study; glial activation; in vivo; mouse model; neuroinflammation; novel therapeutic intervention; novel therapeutics; painful neuropathy; prevent; receptor; receptor function

Project Summary Persistent pain states, arising from inflammatory conditions, such as in arthritis, diabetes, HIV, and chemotherapy among others, have an extraordinary negative impact on quality of life. A common feature of these initiating events is the release of damage-associated molecular pattern (DAMP) molecules, which can activate Toll-like receptor-4 (TLR4). Our previous studies suggest that TLR4 is critical in mediating the transition from acute to persistent pain. TLR4 as well as other inflammatory receptors localize to lipid raft microdomains on the plasma membrane. Lipid rafts, enriched with cholesterol and sphingomyelin, facilitate ligand-mediated receptor dimerization and downstream signaling. Removal of cholesterol from the plasma membrane reduces lipid rafts and often results in inhibition of receptor function. We have found that the secreted apoA-I binding protein (AIBP) accelerates cholesterol removal, disrupts lipid rafts, prevents TLR4 dimerization and inhibits microglia inflammatory responses to LPS. Furthermore, because AIBP binds to TLR4 and its affinity increases when TLR4 is activated by an agonist, we propose that AIBP targets cholesterol removal to lipids rafts harboring activated TLR4. In our recent work, we have also found that this mechanism is relevant to regulation of neuropathic pain states. Intrathecal injections of recombinant AIBP prevented LPS-induced tactile allodynia and, remarkably, reversed established cisplatin-induced allodynia. Based on these findings, we propose that targeted, AIBP- mediated disruption of lipid rafts and its effects upon TLR4 signaling can be a potential therapeutic strategy in treating neuropathic pain states. The Specific Aims of this proposal are: (1) to test the hypothesis that AIBP targets lipid rafts harboring activated TLR4; (2) to test the hypothesis that AIBP reduces glial activation and neuroinflammation in mouse models of neuropathic pain; and (3) to identify the origin and function of endogenous AIBP in the spinal cord. To test these hypothesis, we propose experiments, in vivo and in isolated glial cells, to elucidate the AIBP-TLR4 binding and lipid raft mechanism, and to characterize glial activation and neuroinflammation states. We will also make AIBP variants with mutated apoA-I or TLR4 binding interfaces to validate the proposed mechanism. Using our unique AIBP knockout and AIBP flox/flox mice, we will identify the role of endogenous AIBP in lipid raft regulation and neuroinflammation. In summary, our proposed experiments will elucidate the mechanisms by which AIBP reduces neuroinflammation and alleviates neuropathic pain. Our studies may also suggest that raising AIBP levels in the CNS may be a novel therapeutic approach to treat persistent pain states.

项目摘要 持续疼痛状态，由炎症状态引起，如关节炎、糖尿病、艾滋病毒和 化疗等，对生活质量有非同寻常的负面影响。这些产品的一个共同特点是 启动事件是损伤相关分子模式(DAMP)分子的释放，它可以激活 Toll样受体-4(TLR4)。我们之前的研究表明，TLR4在调节从 剧烈到持续性的疼痛。TLR4和其他炎症受体定位于脂筏微域。 质膜。富含胆固醇和鞘磷脂的脂筏促进配体介导的受体 二聚化和下游信号传递。从质膜上去除胆固醇可以减少脂筏 并经常导致受体功能的抑制。我们发现分泌的载脂蛋白A-I结合蛋白(AIBP) 加速胆固醇清除，破坏脂筏，防止TLR4二聚化，抑制小胶质细胞 对内毒素的炎症反应。此外，由于AIBP与TLR4结合，其亲和力在TLR4时增加 是由激动剂激活的，我们认为AIBP的靶向是去除含有激活的脂筏的胆固醇。 TLR4.在我们最近的工作中，我们还发现这种机制与神经病理性疼痛的调节有关 各州。鞘内注射重组AIBP可预防内毒素诱导的触觉过敏，而且值得注意的是， 逆转顺铂诱导的痛觉过敏。基于这些发现，我们建议有针对性的AIBP- 脂筏介导的破坏及其对TLR4信号的影响可能是一种潜在的治疗策略 治疗神经病理性疼痛状态。这一提议的具体目的是：(1)检验AIBP 靶向含有活化的TLR4的脂筏；(2)验证AIBP降低神经胶质细胞活化和 神经病理性疼痛小鼠模型中的神经炎症；以及(3)确定内源性疼痛的来源和功能 脊髓内的AIBP。为了验证这些假设，我们建议在体内和在分离的神经胶质细胞中进行实验，以 阐明AIBP-TLR4结合和脂筏机制，并表征神经胶质细胞的活化和 神经炎症状态。我们还将使AIBP变体具有突变的apoA-I或TLR4结合接口，以 对提出的机制进行了验证。使用我们独特的AIBP基因敲除和AIBP FLOX/FLOX小鼠，我们将识别 内源性AIBP在脂筏调节和神经炎症中的作用。总而言之，我们提议的实验 将阐明AIBP减轻神经炎症和减轻神经病理性疼痛的机制。我们的 研究还可能表明，提高中枢AIBP水平可能是一种新的治疗方法 持续的疼痛状态。