Exogenous Chemical Probes of TLR-Mediated Neuroinflammation

TLR 介导的神经炎症的外源化学探针

• 批准号: 8589736
• 负责人: Hang Hubert Yin
• 金额: $ 28.98万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-05 至 2017-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8589736
• 关键词: Absence of pain sensation; Acute; Adverse effects; Analgesics; Animal Model; Animal Testing; Binding; Biochemical; Biological Assay; Blood - brain barrier anatomy; Brain; Cell Line; Cellular Assay; Chemicals; Complex; Dependence; Development; Dimerization; Drug Kinetics; Drug Targeting; Endotoxins; Enzymes; Generations; Goals; Hydrocarbons; Immune; In Vitro; Inflammatory Response; Ligands; Light; Link; Lipopolysaccharides; Literature; Mediating; Membrane; Meperidine; Methadone; Methods; Microglia; Molecular; Molecular Conformation; Morphine; Myelogenous; Neuraxis; Neurobiology; Neuroglia; Neurons; Opiates; Opioid; Outcome; Oxycodone; Pain management; Pathway interactions; Peptides; Permeability; Pharmaceutical Chemistry; Pharmaceutical Preparations; Property; Proteins; Radar; Reporting; Research; Resistance; Resolution; Role; Signal Pathway; Signal Transduction; Specificity; Spinal Cord; Structure; Structure-Activity Relationship; Technology; Testing; Therapeutic; Vertebral column; Work; Yin; base; clinical efficacy; clinically relevant; computational chemistry; design; drug candidate; drug discovery; improved; in vitro testing; in vivo; inhibitor/antagonist; innovation; insight; interest; macrophage; molecular recognition; multidisciplinary; neglect; neuroinflammation; novel; protein complex; prototype; public health relevance; receptor; receptor function; response; scaffold; small molecule; toll-like receptor 4; tool

DESCRIPTION (provided by applicant): After years of neglect, glial cells are finally registering on drug developers' radar. Evidence has accrued over the last seven years that glia are activated by opioids (e.g. morphine, methadone, meperidine, and oxycodone) and that this opioid-induced glial response suppresses opioid analgesia, resulting in the development of opioid tolerance and dependence. A literature has developed linking opiate efficacy and side effects to their influence on glial cells within the central nervous system (CNS) via the signaling pathway mediated by toll-like receptor 4 (TLR4). In a recent report, the Yin lab has provided the first direct evidence that morphine creates its neuroinflammatory effects by binding to the TLR4 accessory protein, MD-2, and inducing TLR4/MD-2 dimerization and subsequent TLR4 signaling activation in a similar fashion to the classical TLR4 ligand, lipopolysaccharide (LPS; endotoxin). Further, morphine induces neuroinflammation solely through its binding in a specific LPS-binding pocket of MD-2, indicating that disruption of the essential TLR4/MD-2 interactions is sufficient to suppress morphine-induced neuroinflammation. The overall objective of the current proposal is to validate the TLR4/MD-2 complex as a feasible target to suppress morphine-induced neuroinflammation by exogenous chemical probes. Our central hypothesis is that by blocking the formation of the TLR4/MD-2 complex, opioid-induced inflammatory response can also be suppressed and thereby enhance morphine analgesia. The proposed research is significant because it is expected to validate the TLR4/MD-2 complex as a novel target for improving the analgesic efficacy of opioids. The proposed research is innovative because it is the first drug discovery approach attempting to regulate opioid-induced glial activation while almost all previous research focused on neurons. The studies are built on a strong collaborative team with expertise that optimizes its chance to effectively bridge the atomic details of TLR4 activation with the macroscopic pain management inefficiencies of opioid use. Aim 1 and Aim 2 are two independent, parallel approaches that aim to attain highly specific inhibitors of the TLR4/MD-2 interactions. We aim to develop previously identified MD-2 peptides and T5342126 derivatives as potent, selective inhibitors of the TLR4/MD-2 complex with desired PK/PD properties. Aim 3 will test the working hypothesis that by disrupting the TLR4/MD- 2 complex, opioid-induced neuroinflammation can also be blocked, thus enhancing acute opioid analgesia. The optimized inhibitors from Aims 1 and 2 will be tested in vitro using various cell lines, in ex vivo microglia, as well as in animal models. The proposed studies, if successful, are projected to yield significant novel outcome: First, the results will further the understanding of the mechanism of clinically relevant opioid-induced neuroinflammation. Second, the TLR4/MD-2 complex will be validated as a feasible target for developing neuroinflammation suppressant. Third, the stapled peptide and small-molecule antagonists of the TLR4 pathway identified from the proposed research will serve as prototypes for potential drug candidates.

描述（由申请人提供）：经过多年的忽视，神经胶质细胞终于在药物开发者的雷达上注册。在过去的七年中，越来越多的证据表明胶质细胞被阿片类药物（例如吗啡、美沙酮、哌替啶和羟考酮）激活，并且这种阿片类药物诱导的胶质细胞反应抑制阿片类药物镇痛，导致阿片类药物耐受性和依赖性的发展。已有文献将阿片类药物的疗效和副作用与其通过信号传导对中枢神经系统（CNS）内神经胶质细胞的影响联系起来 Toll样受体4（TLR 4）介导的信号通路。在最近的一份报告中，Yin实验室提供了第一个直接证据，表明吗啡通过与TLR 4辅助蛋白MD-2结合并诱导TLR 4/MD-2二聚化以及随后的TLR 4信号转导激活来产生神经炎症效应，其方式与经典的TLR 4配体脂多糖（LPS;内毒素）相似。此外，吗啡仅通过其在MD-2的特异性LPS结合口袋中的结合诱导神经炎症，表明基本TLR 4/MD-2相互作用的破坏足以抑制吗啡诱导的神经炎症。目前的建议的总体目标是验证TLR 4/MD-2复合物作为一个可行的目标，抑制吗啡诱导的神经炎症的外源性化学探针。我们的中心假设是，通过阻断TLR 4/MD-2复合物的形成，阿片类药物诱导的炎症反应也可以被抑制，从而增强吗啡镇痛。这项研究意义重大，因为它有望验证TLR 4/MD-2复合物作为改善阿片类药物镇痛效果的新靶点。这项研究具有创新性，因为它是第一个试图调节阿片类药物诱导的神经胶质激活的药物发现方法，而几乎所有以前的研究都集中在神经元上。这些研究建立在一个强大的合作团队的基础上，该团队具有专业知识，可以优化其机会，有效地将TLR 4激活的原子细节与阿片类药物使用的宏观疼痛管理效率低下联系起来。目的1和目的2是两种独立的平行方法，旨在获得TLR 4/MD-2相互作用的高度特异性抑制剂。我们的目标是开发先前鉴定的MD-2肽和T5342126衍生物作为具有所需PK/PD性质的TLR 4/MD-2复合物的有效的选择性抑制剂。目的3将测试工作假设，即通过破坏TLR 4/MD- 2复合物，阿片类药物诱导的神经炎症也可以被阻断，从而增强急性阿片类药物镇痛。将使用各种细胞系、离体小胶质细胞以及动物模型对目标1和2的优化抑制剂进行体外测试。这些研究如果成功，预计将产生重大的新成果：首先，结果将进一步了解机制 临床相关的阿片类药物引起的神经炎症第二，TLR 4/MD-2复合物将被验证为开发神经炎症抑制剂的可行靶标。第三，从拟议的研究中确定的TLR 4途径的钉合肽和小分子拮抗剂将作为潜在候选药物的原型。