Molecular biophysics of integrin activation by oxysterols and rational discovery of small-molecule modulators

氧甾醇激活整合素的分子生物物理学和小分子调节剂的合理发现

基本信息

批准号：
10255990
负责人：
Senthil Kumar Natesan
金额：
$ 29.07万
依托单位：
WASHINGTON STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-10 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10255990
关键词：
25-hydroxycholesterol Affect Affinity Anti-Inflammatory Agents Area Autoimmune Diseases Binding Binding Sites Biochemical Biological Biological Response Modifiers Biophysics Brain Brain Diseases Cardiovascular Diseases Cell model Cells Central Nervous System Degenerative Diseases Cholesterol Communicable Diseases Computational Technique Data Degenerative Disorder Development Disease Docking Extracellular Matrix Extracellular Matrix Proteins Focal Adhesion Kinase 1 Free Energy Goals Homeostasis Human body Immune Immune System Diseases Immune system Immunotherapy In Vitro Inflammation Inflammatory Inflammatory Response Integrin alpha5beta1 Integrins Interleukin-6 Knowledge Ligands Lipids Malignant Neoplasms Mediating Membrane Mission Modeling Modification Molecular Molecular Conformation Natural Immunity Oxides Pathologic Pathologic Processes Pathway interactions Pattern recognition receptor Pharmaceutical Preparations Physiological Processes Play Production Property Public Health Publications RGD (sequence)Regulation Research Role Signal Transduction Site Solvents Specificity Structure Surface TNF gene Therapeutic Thrombosis Time United States National Institutes of Health Virus Activation Virus Diseases adaptive immunity base biophysical techniques combat cytokine immune activation in silico in vivo in vivo Model in vivo evaluation innovation insight interdisciplinary approach macrophage molecular dynamics molecular recognition mouse model novel pharmacophore prevent response screening simulation small molecule small molecule therapeutics therapeutic target virtual screening

项目摘要

PROJECT SUMMARY/ABSTRACT Oxysterols are oxygenated metabolites of cholesterol formed in the human body and are involved in a plethora of physiological and pathological processes such as lipid homeostasis, inflammation, innate and adaptive immunity, cancer, and brain degenerative diseases. Specifically, 25-hydroxycholesterol (25HC) is now established as an important regulator of the immune system, and is produced by immune cells in response to viral infection and activation of pattern recognition receptors. Recently, we uncovered a novel cellular mechanism of 25HC-mediated regulation of the proinflammatory response. We showed that 25HC amplifies the activation of immune cells and increases the production of immune mediators such as TNF and IL-6, by directly binding to αvβ3 and α5β1 integrins and activating the integrin-focal adhesion kinase pathway. We also discovered that 25HC binds to integrins at a novel binding site (site 2), distinct from the site where the extracellular matrix (ECM) ligands containing an Arg-Gly-ASP (RGD) motif are known to bind. Binding of 25HC at site 2 produces significant conformational changes in the specificity-determining loop (SDL) of integrins, near the RGD-binding site. The effect of such conformational changes in the SDL on the binding of ECM ligands, as well as the basis of 25HC- mediated allosteric signaling mechanism underlying integrin activation, are not known. Our hypothesis is that binding of 25HC to integrins at site 2 triggers conformational changes in the SDL that result in efficient binding of ECM ligands producing further modification of innate inflammatory response. We also hypothesize that small molecule modulators blocking 25HC-integrin interaction would serve as an efficient anti-inflammatory therapeutic strategy to combat various inflammatory diseases. Accordingly, the central objective of this proposal is to elucidate the molecular mechanisms of integrin activation by oxysterols and to identify selective small molecule modulators targeting site 2 of integrins for potential therapeutic applications. The objective of this project will be accomplished by the following three specific aims: 1) elucidate the molecular basis and conformational dynamics of integrin activation by 25HC; 2) examine the molecular recognition of integrins by non-25HC oxysterols; and 3) identify and evaluate small-molecule modulators targeting the 25HC binding site of integrins. We will utilize state-of-the-art computational techniques such as molecular docking, molecular dynamics simulations, and pharmacophore-based virtual screening to delineate the structural basis and conformational dynamics involved in activation of integrins and to identify high affinity ligands for site 2 of integrins. In addition, our well-established in vitro and in vivo models will be employed to validate our in silico findings and evaluate top ligands. Our multidisciplinary approach is innovative and together, the proposed studies will have a broad impact by offering fundamental insights to the interplay between oxysterols and integrins that culminates in amplification of the inflammatory response. Furthermore, this project will identify one or more modulators of integrin-25HC interactions, thereby advancing potential anti-inflammatory therapies for immunologic and infectious diseases.

项目概要/摘要氧甾醇是人体内形成的胆固醇的氧化代谢物，参与多种代谢过程。生理和病理过程，如脂质稳态、炎症、先天性和适应性具体来说，25-羟基胆固醇（25HC）现在是免疫、癌症和脑退行性疾病。被确立为免疫系统的重要调节剂，由免疫细胞响应于最近，我们发现了一种新的细胞机制。 25HC 介导的促炎症反应的调节我们发现 25HC 增强了促炎反应的激活。免疫细胞并通过直接结合来增加免疫介质的产生，例如 TNF 和 IL-6 αvβ3 和 α5β1 整合素并激活整合素-粘着斑激酶途径。 25HC 在一个新的结合位点（位点 2）与整合素结合，该位点与细胞外基质 (ECM) 结合的位点不同已知含有 Arg-Gly-ASP (RGD) 基序的配体与 25HC 在位点 2 的结合产生显着的结合。 RGD 结合位点附近整联蛋白特异性决定环 (SDL) 的构象变化。 SDL 中的这种构象变化对 ECM 配体结合的影响，以及 25HC- 的基础整合素激活背后介导的变构信号机制尚不清楚。 25HC 与整合素在位点 2 的结合触发 SDL 的构象变化，从而实现有效的结合 ECM 配体对先天炎症反应产生进一步的改变，我们还招募了那个小分子。阻断 25HC-整合素相互作用的分子调节剂将作为一种有效的抗炎治疗方法因此，该提案的中心目标是对抗各种炎症性疾病。阐明氧甾醇激活整合素的分子机制并鉴定选择性小分子针对整合素位点 2 的调节剂的潜在治疗应用该项目的目标是。通过以下三个具体目标来实现：1）阐明分子基础和构象动力学 25HC 整合素激活；2) 检查非 25HC 氧甾醇对整合素的分子识别； 3) 识别和评估针对整合素 25HC 结合位点的小分子调节剂。最先进的计算技术，例如分子对接、分子动力学模拟和基于药效团的虚拟筛选，描绘所涉及的结构基础和构象动力学整合素的激活和识别整合素位点 2 的高亲和力配体此外，我们的成熟。体外和体内模型将用于验证我们的计算机研究结果并评估我们的顶级配体。多学科方法是创新的，并且拟议的研究将通过提供广泛的影响对氧甾醇和整合素之间相互作用的基本见解，最终导致放大此外，该项目将鉴定一种或多种整合素25HC调节剂。相互作用，从而推进免疫学和传染病的潜在抗炎疗法。