Characterization of biased airway smooth muscle TAS2R agonists for treating asthma

偏向气道平滑肌 TAS2R 激动剂治疗哮喘的表征

• 批准号: 10322110
• 负责人: Stephen B Liggett
• 金额: $ 54.16万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10322110
• 关键词: Affect; Affinity; Age; Agonist; Air Movements; Arrestins; Asthma; Back; Binding; Binding Sites; Biochemical; Biology; Bronchial Spasm; Bronchodilator Agents; Cell model; Cells; Characteristics; Clinical; Collection; Complex; Coupling; Cytometry; Data; Disease; Docking; Dose; Engineering; Ethnic Origin; Functional disorder; G-Protein-Coupled Receptors; GTP-Binding Proteins; Genetic Engineering; Human; Intervention; Learning; Libraries; Ligand Binding; Ligands; Lung; Magnetism; Methods; Modality; Modeling; Molecular Conformation; Morbidity - disease rate; Obstruction; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacology; Phenotype; Physiological; Physiology; Prevention; Process; Property; Public Health; Relaxation; Resistance; Signal Transduction; Slice; Smooth Muscle Myocytes; Structure; System; Tachyphylaxis; Taste Buds; Techniques; Therapeutic; Time; Translations; Work; airway obstruction; asthmatic; attenuation; base; beta-arrestin; cell type; desensitization; disorder control; experience; experimental study; in silico; interest; models and simulation; molecular modeling; mortality; novel; pharmacophore; predictive modeling; prevent; receptor; recruit; respiratory smooth muscle; response; simulation; three dimensional structure; treatment optimization; virtual; virtual screening

Asthma remains a major public health issue worldwide, affecting all ages and ethnicities, with 50% of patients experiencing inadequate control of the disease. Constricted airways from contraction of airway smooth muscle is the major cause of airflow obstruction, and morbidity and mortality, in asthma. Despite this key point for intervention, only one class of direct bronchodilators (-agonists) are available for treatment, and they are suboptimal for many patients. We have discovered bitter taste receptors (TAS2Rs) on human airway smooth muscle (HASM) cells which signal by a unique mechanism. When activated, TAS2Rs markedly relax HASM and relieve airway obstruction that is otherwise resistant to -agonists. However, the known TAS2R agonists have low affinity and evoke desensitization (tachyphylaxis) of the relaxation response over time via -arrestin mechanisms. The overarching hypothesis is that TAS2R agonists with novel structures can be highly effective in relaxing airways in an asthmatic milieu and yet not evoke tachyphylaxis. The broad long-term objectives are to determine the 3D structures and binding sites of two TAS2Rs expressed on HASM (R5 and R14) and then use these structures to perform virtual docking of an agnostic ultra-large compound library to identify potential ligands. These hits will be examined in engineered model cells, but will be most intensely studied within the context of the physiology of HASM cells, and human airways, under asthmatic conditions to delineate novel ways to engage the receptor that are biased towards relaxation and away from desensitization. Aim 1 will computationally determine the structures and binding sites for R5 and R14 using methods that include 13 trillion combinations of the residues to determine favorable energy conformations of inactive and active states. The structures will be used to dock compounds from a highly diverse library. These will be studied in Aim 2 to determine potency and efficacy in genetically engineered model cells and in HASM cells from nonasthmatic and asthmatic lungs. In Aim 3, the most favorable compounds will be studied to ascertain -arrestin engagement and biasing away from desensitization in model cells, HASM cells, and human lungs under asthmatic conditions. Results from Aims2/3 will be fed back into Aim1 to further refine a model of biased agonists for these HASM TAS2Rs. Based on our preliminary data that support all three Aims, we will learn about the structural requirements for biasing for these receptors. And, we anticipate that multiple highly effective agonists with unexpected structures will be identified and that their bronchodilating properties in asthma will represent a new class of powerful non-desensitizing agents for treating and preventing bronchospasm.

哮喘仍然是世界范围内的一个主要公共卫生问题，影响所有年龄和种族，50%的患者 对疾病的控制不足。气道平滑肌收缩导致的气道狭窄 是哮喘中气流阻塞、发病率和死亡率的主要原因。尽管这一关键点， 在介入治疗中，只有一类直接支气管扩张剂（β-激动剂）可用于治疗， 对许多患者来说是不理想的。我们在人气道平滑肌上发现了苦味受体（TAS 2 Rs）， 肌肉（HASM）细胞通过独特的机制发出信号。当被激活时，TAS 2 R显著地松弛HASM， 缓解气道阻塞，否则对β-受体激动剂有抵抗力。然而，已知的TAS 2 R激动剂具有 低亲和力和诱发脱敏（快速耐受）的松弛反应随着时间的推移，通过抑制蛋白 机制等总体假设是具有新结构的TAS 2 R激动剂可以是高度有效的 在哮喘环境中放松气道，但不会引起快速耐受。广泛的长期目标是 确定HASM上表达的两个TAS 2 R（R5和R14）的3D结构和结合位点，然后 使用这些结构来执行不可知的超大型化合物库的虚拟对接， 配体。这些命中将在工程模型细胞中进行检查，但将在实验室中进行最深入的研究。 在哮喘条件下，HASM细胞和人类气道的生理学背景，以描绘新的方式 来激活偏向于放松而非脱敏的受体。目标1将 计算确定R5和R14的结构和结合位点，使用的方法包括13万亿 残基的组合以确定非活性状态和活性状态的有利能量构象。的 结构将用于对接来自高度多样化库的化合物。这些将在目标2中研究， 确定在基因工程模型细胞和来自非哮喘的HASM细胞中的效力和功效， 哮喘肺在目标3中，将研究最有利的化合物以确定抑制蛋白结合 以及在哮喘条件下在模型细胞、HASM细胞和人肺中偏离脱敏。 Aims 2/3的结果将反馈至Aim 1，以进一步完善这些HASM的偏倚激动剂模型 TAS2Rs。根据我们支持所有三个目标的初步数据，我们将了解结构 对这些受体的偏置要求。而且，我们预计，多种高效激动剂， 将发现意想不到的结构，它们在哮喘中的支气管扩张特性将代表一种新的 一类用于治疗和预防支气管痉挛的强效非脱敏剂。