Identification of allosteric molecules for DOR-KOR heteromer-mediated peripheral analgesia

DOR-KOR 异聚体介导的外周镇痛变构分子的鉴定

• 批准号: 10608439
• 负责人: WILLIAM P CLARKE
• 金额: $ 55.78万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10608439
• 关键词: Absence of pain sensation; Adult; Adverse effects; Afferent Neurons; Affinity; Agonist; Analgesics; Binding; COVID-19 pandemic; Cells; Chemicals; Clinical; Dangerousness; Data; Dependence; Development; Effectiveness; Future; G-Protein-Coupled Receptors; Human Resources; In Vitro; Injections; Lead; Libraries; Life; Ligands; Local Anesthetics; Mediating; Motor Neurons; Nociception; Nociceptors; Opioid; Opioid Analgesics; Opioid Receptor; Pain; Pain management; Penetrance; Peripheral; Persons; Pharmaceutical Preparations; Phase; Physiological; Property; Protomer; Rattus; Reporting; Sensory; Series; Structure; Structure-Activity Relationship; System; Testing; Therapeutic; Toxicology; Training; United States National Institutes of Health; Ventilatory Depression; addiction; antagonist; antinociception; chronic pain; collaborative approach; daily pain; delta opioid receptor; design; drug-like compound; effective therapy; efficacy evaluation; experience; high throughput screening; in silico; in vivo; kappa opioid receptors; mu opioid receptors; neurotransmission; novel; opioid epidemic; peripheral pain; programs; receptor; research clinical testing; screening; small molecule libraries

Current clinically prescribed analgesics target mu opioid receptors within the CNS and can produce dangerous and often lethal adverse effects, including respiratory depression and addiction. Importantly, these analgesics are principally responsible for precipitating the opioid crisis, which has only worsened with the SARS- CoV-2 pandemic. Thus, alternative approaches for treatment of pain are badly needed. As evidenced by the efficacy of local anesthetics, a promising approach to treat pain is to inhibit peripheral pain-sensing neurons (nociceptors) that mediate pain neurotransmission. We have found that delta opioid receptor (DOR)-kappa opioid receptor (KOR) heteromers are expressed and when activated produce strong and sustained antinociception. Thus, the DOR-KOR heteromer may be a promising target for development of peripherally-restricted analgesic drugs to treat nociceptive pain. In this application, we propose a multifaceted and highly collaborative approach to identify small, drug-like molecules that selectively activate the DOR-KOR heteromer expressed by nociceptors. Our approach to develop drugs that selectively activate the DOR-KOR heteromer is to take advantage of a unique property of GPCR heteromers – interprotomer allosterism. Interprotomer allosterism is where an orthosteric ligand for one of the protomers in the heteromeric pair allosterically alters the affinity and/or intrinsic efficacy of the orthosteric ligand for the other protomer. We have demonstrated that such interprotomer allosterism occurs for ligands acting at the DOR-KOR heteromer. Moreover, we have identified one ligand, 6’- GNTI, that is an antagonist at both DOR and KOR in nociceptors, but via interprotomer allosterism, selectively activates the DOR-KOR heteromer resulting in strong antinociception. Here we will take advantage of this inter- protomer allosterism to identify novel heteromer-selective compounds. The Specific Aims of this project are to identify novel DOR-KOR heteromer ligands using 1) a synthetic strategy based on structurally diverse chemical series; 2) high-throughput screening (HTS) of chemical libraries of drug-like compounds; and 3) structure-based in-silico screening of libraries of commercially-available chemical compounds. Hits will be initially identified using HEK cell expression systems. Potential candidate compounds that emerge from the in vitro screens will undergo ADME and receptor selectivity screening. Suitable compounds will then be screened for peripherally-mediated antinociceptive efficacy mediated by the DOR-KOR heteromer in nociceptors in rats. Compounds that emerge from this project (we expect ~5 compounds) will undergo further development using the NIH BPN UG3/UH3 program to advance candidates through IND-enabling toxicology and phase 1 clinical testing for safer and effective treatment of pain. We also will have obtained valuable structure-activity relationship information about the identified DOR and KOR ligands that will aid in the future design of DOR, KOR and DOR-KOR heteromer ligands. Successful application of this approach (interprotomer allosterism) could be applied for other GPCR heteromers to help further our understanding of the function of heteromers in physiological systems.

目前临床处方的镇痛药靶向CNS内的μ阿片样物质受体，并且可以产生 危险的，往往是致命的副作用，包括呼吸抑制和成瘾。重要的是这些 止痛药是引发阿片类药物危机的主要原因，而SARS使这一危机进一步恶化， CoV-2大流行。因此，迫切需要用于治疗疼痛的替代方法。证明了这 局部麻醉药的有效性，一种有前途的治疗疼痛的方法是抑制外周痛觉神经元 （伤害感受器）介导疼痛神经传递。我们发现δ阿片受体（DOR）-κ阿片样物质 受体（KOR）异聚体被表达，并且当被激活时产生强烈和持续的抗伤害感受。 因此，DOR-KOR异聚体可能是外周限制性淋巴细胞癌发展的一个有希望的靶点。 用于治疗伤害性疼痛的止痛药。在这个应用程序中，我们提出了一个多方面的和高度协作的 一种鉴定选择性激活DOR-KOR异聚体的小的药物样分子的方法， 伤害感受器我们开发选择性激活DOR-KOR异聚体的药物的方法是 GPCR异聚体的独特性质--蛋白质间变构的优势。原异构体间变构是 其中异聚体对中的原聚体之一的正构配体变构地改变亲和力和/或 正构配体对其他原聚体的内在功效。我们已经证明，这种互变异构体 作用于DOR-KOR异聚体的配体发生变构。此外，我们还鉴定了一种配体，6 '- GNTI是伤害感受器中DOR和KOR的拮抗剂，但通过原异构体间变构作用，选择性地 激活DOR-KOR异聚体，导致强烈的抗伤害感受。在这里，我们将利用这间- 原异构体变构来鉴定新的异源异构体选择性化合物。该项目的具体目标是 鉴定新DOR-KOR异聚体配体，其使用1）基于结构上不同的化学物质的合成策略 系列; 2）药物样化合物的化学文库的高通量筛选（HTS）;和3）基于结构的 对市售化合物文库进行计算机筛选。点击将首先使用 HEK细胞表达系统。从体外筛选中出现的潜在候选化合物将经历 ADME和受体选择性筛选。然后将筛选合适的化合物用于外周介导的免疫调节。 DOR-KOR异聚体在大鼠伤害感受器中介导的抗伤害感受功效。出现的化合物 该项目（我们预计约5种化合物）将使用NIH BPN UG3/UH3进行进一步开发 通过IND毒理学和1期临床试验推进候选人的计划， 有效治疗疼痛。我们还将获得关于以下方面的有价值的结构-活性关系信息： 已鉴定的DOR和KOR配体将有助于未来设计DOR、KOR和DOR-KOR异聚体 配体。这种方法的成功应用（原异构体间变构）可以应用于其他GPCR 异聚体，以帮助我们进一步了解异聚体在生理系统中的功能。