Project 4 - OGR1- and TSPO- dependent mechanisms mediated by benzodiazepines affecting ASM contraction

项目摘要 在前一个周期中，我们表征了某些苯二氮卓类药物与降压药物协同作用的能力。 细胞外pH，通过激活质子-肌动蛋白来调节气道平滑肌(ASM)的信号和功能。 传感G蛋白偶联受体(GPCR)OGR1(卵巢癌G蛋白偶联受体1，又名GPR68)。 重要的是，我们发现OGR1下游激活的多个信号通路可能是 选择性地激活(即，偏向)，对ASM的收缩和增殖产生不同的影响。在这 第二个周期我们建议：1)描述OGR1信号发生偏向的机制；2) 详细说明苯二氮类药物的一个额外的、线粒体依赖的效应臂，它也抑制ASM收缩； 3)利用模型来开发针对这些机制的更有效的苯二氮卓类药物。 这些目标将通过三个具体目标来实现。在目标1中，我们将采用基于细胞的集成模型 以阐明不同的苯二氮卓类药物如何促进特定的OGR1-和外周血细胞 苯二氮卓类受体--调节ASM收缩的信号。在目标2中将建立 通过评估决定G蛋白偶联的OGR1的结构-功能属性来偏向OGR1信号，以及 拦截器的偏置作用。在目标3中，我们将与Core A合作，使用分子建模来 设计新的变构调节剂，使OGR1信号偏向Gs/cAMP/PKA途径的激活，并 相关治疗益处，使用AIMS 1和2中使用的信号和功能分析来指导 开发和确定最有效的药物。通过建立调停质量的机制 通过OGR1发出信号，并开发最佳偏向OGR1并促进支气管扩张的新药物，我们将 大大推进了受体生物学和哮喘治疗领域的发展。

Project Summary In the previous cycle we characterized the ability of certain benzodiazepines, in cooperation with decreased extracellular pH, to regulate airway smooth muscle (ASM) signaling and function via activation of the proton- sensing G protein-coupled receptor (GPCR) OGR1 (Ovarian cancer G-protein coupled receptor 1 aka GPR68). Importantly, we discovered that the multiple signaling pathways activated downstream of OGR1 could be selectively activated (i.e., biased) to produce differential effects on ASM contraction and proliferation. In this second cycle we propose to: 1) delineate the mechanisms by which the biasing of OGR1 signaling occurs; 2) detail an additional, mitochondrial-dependent effector arm of benzodiazepines that also inhibits ASM contraction; and 3) employ modeling to develop more efficacious benzodiazepine-like drugs that target these mechanisms. These goals will be achieved through 3 Specific Aims. In Aim 1 we will employ cell-based and integrative models of ASM contraction to clarify the how different benzodiazepines promote specific OGR1- and peripheral benzodiazepine receptor- signaling to regulate ASM contraction. In Aim 2 will establish the mechanistic basis of biased OGR1 signaling by assessing structure-function properties of OGR1 that dictate G protein coupling, and the biasing function of arrestins. In Aim 3 in collaboration with Core A we will employ molecular modeling to design new allosteric modulators to bias OGR1 signaling towards Gs/cAMP/PKA pathway activation and the associated therapeutic benefits, using the signaling and functional assays employed in Aims 1 and 2 to guide development and identify the most efficacious drugs. By establishing mechanisms mediating qualitative signaling by OGR1 and developing new agents that optimally bias OGR1 and promote bronchodilation, we will significantly advance the fields of both receptor biology and asthma therapeutics.