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.

哮喘仍然是全球主要的公共卫生问题，影响所有年龄段和种族，50% 的患者患有哮喘 疾病控制不力。气道平滑肌收缩导致气道收缩 是哮喘气流阻塞、发病率和死亡率的主要原因。尽管有这个关键点 在干预期间，只有一类直接支气管扩张剂（激动剂）可用于治疗，并且它们 对于许多患者来说不是最理想的。我们在人类呼吸道平滑肌上发现了苦味受体（TAS2R） 肌肉（HASM）细胞通过独特的机制发出信号。激活后，TAS2R 会显着放松 HASM， 缓解对  激动剂耐药的气道阻塞。然而，已知的 TAS2R 激动剂 随着时间的推移，通过 -arrestin 产生低亲和力并引起松弛反应脱敏（快速耐受） 机制。总体假设是具有新颖结构的 TAS2R 激动剂可以非常有效 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 TAS2R（R5 和 R14）的 3D 结构和结合位点，然后 使用这些结构对不可知的超大型化合物库进行虚拟对接，以识别潜在的 配体。这些命中将在工程模型细胞中进行检查，但将在 哮喘条件下 HASM 细胞和人类呼吸道的生理学背景，以描绘新的方法 接合偏向松弛且远离脱敏的受体。目标1将 使用包含 13 万亿的方法计算确定 R5 和 R14 的结构和结合位点 残基的组合以确定非活性和活性状态的有利能量构象。这 结构将用于对接高度多样化的库中的化合物。这些将在目标 2 中进行研究 确定基因工程模型细胞和来自非哮喘和哮喘患者的 HASM 细胞的效力和功效 哮喘肺。在目标 3 中，将研究最有利的化合物以确定 -arrestin 的参与 在哮喘条件下模型细胞、HASM 细胞和人肺中偏向脱敏。 Aims2/3 的结果将反馈至 Aim1，以进一步完善这些 HASM 的偏向激动剂模型 TAS2R。根据支持所有三个目标的初步数据，我们将了解结构 这些受体的偏置要求。而且，我们预计多种高效激动剂 将鉴定出意想不到的结构，并且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。