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

项目概要 在上一个周期中，我们表征了某些苯二氮卓类药物的能力，与减少的合作 细胞外 pH 值，通过激活质子来调节气道平滑肌 (ASM) 信号传导和功能 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 下游激活的多种信号通路可能是 选择性激活（即有偏向）以对 ASM 收缩和增殖产生不同的影响。在这个 第二个周期我们建议：1）描述 OGR1 信号传导偏向发生的机制； 2） 详细描述了苯二氮卓类药物的另一个线粒体依赖性效应臂，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 3 个具体目标来实现。在目标 1 中，我们将采用基于细胞的综合模型 ASM 收缩，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 苯二氮卓受体信号传导调节 ASM 收缩。目标 2 将建立以下机制的基础： 通过评估 OGR1 决定 G 蛋白偶联的结构功能特性来偏向 OGR1 信号传导，以及 视紫红质抑制蛋白的偏向功能。在目标 3 中，我们将与 Core A 合作，利用分子建模来 设计新的变构调节剂，使 OGR1 信号偏向于 Gs/cAMP/PKA 通路激活和 相关的治疗益处，使用目标 1 和 2 中采用的信号传导和功能测定来指导 开发并确定最有效的药物。通过建立调解质量的机制 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 显着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.