Arrestin Selectivity for GPCRs in Airway Smooth Muscle

描述（由申请人提供）：抑制蛋白通过破坏GPCR-G蛋白相互作用和“抑制”受体信号传导能力来调节多种G蛋白偶联受体（GPCR）。虽然相当多的证据arrestins的重要性已经来自研究采用细胞过表达系统，我们的了解arrestin调节内源性GPCR在生理系统是有限的。我们建议表征抑制蛋白调节气道平滑肌（ASM）中GPCR的能力和选择性，最终目标是靶向抑制蛋白，作为改善吸入性β受体激动剂治疗哮喘和COPD疗效的一种手段。基于本文提供的初步数据，我们假设β-抑制蛋白-1和β-抑制蛋白-2对Gq-和Gs-偶联受体的选择性的差异可用于增强β-激动剂松弛由其他GPCR收缩的ASM的能力。目的1和2将建立β-抑制蛋白-1和β-抑制蛋白-2对介导ASM收缩（包括毒蕈碱、半胱氨酰白三烯和组胺受体）或舒张（β-2-肾上腺素和前列腺素E2受体）的那些GPCR的选择性。目的1将利用分子和遗传方法靶向来自人和小鼠的ASM细胞和组织中的β-arrestin-1、β-arrestin-2或两者。将通过GPCR评估抑制蛋白抑制或基因消融对ASM信号传导和收缩特性的影响。目的2将进行补充生理测量，以确定arrestin基因消融对ASM收缩和舒张的调节作用。总的来说，这些研究将提供一个高度机械的arrestin选择性ASM的分析，并确定方法差异调节受体介导的收缩或放松的ASM。 公共卫生相关性：这些研究旨在确定抑制气道平滑肌中的关键调节分子的有效性（作为哮喘治疗）。了解β-arrestin-1或β-arrestin-2如何调节平滑肌中的受体，可能使我们能够提高药物松弛平滑肌的能力，同时抑制导致气道收缩和喘息的刺激。

DESCRIPTION (provided by applicant): Arrestins regulate numerous G protein-coupled receptors (GPCRs) by disrupting GPCR-G protein interaction and "arresting" the ability of receptors to signal. Although considerable evidence of the importance of arrestins has come from studies employing cellular overexpression systems, our understanding of arrestin regulation of endogenous GPCRs in physiological systems is limited. We propose to characterize the capacity and selectivity of arrestins for regulating GPCRs in airway smooth muscle (ASM), with the ultimate goal of targeting arrestins as a means of improving the therapeutic efficacy of inhaled beta-agonists in the treatment of asthma and COPD. Based on preliminary data presented herein, we hypothesize that differences in beta-arrestin-1 and beta-arrestin-2 selectivity for Gq- and Gs- coupled receptors can be exploited to enhance the ability of beta-agonists to relax ASM contracted by other GPCRs. Aims 1 & 2 will establish the selectivity of beta-arrestin-1 and beta-arrestin-2 for those GPCRs that either mediate contraction (including muscarinic, cysteinyl leukotriene, and histamine receptors) or relaxation (beta-2-adreneric and prostaglandin E2 receptors) of ASM. Aim 1 will utilize molecular and genetic approaches to target beta-arrestin-1, beta-arrestin-2, or both in ASM cells and tissue derived from both humans and mice. Affects of arrestin inhibition or gene ablation on both ASM signaling and contractile properties by GPCRs will be assessed. Aim 2 will perform complementary physiological measurements to determine the effect of arrestin gene ablation on the regulation of ASM contraction and relaxation in vivo. Collectively, these studies will provide a highly mechanistic analysis of arrestin selectivity in ASM and identify approaches for differentially regulating receptors that mediate contraction or relaxation of ASM. PUBLIC HEALTH RELEVANCE: These studies seek to identify the usefulness (as an asthma therapy) of inhibiting a key regulatory molecule in airway smooth muscle. Understanding how beta-arrestin-1 or beta-arrestin-2 regulate receptors in smooth muscle may allow us to improve the ability of drugs to relax smooth muscle while at the same time inhibiting the stimuli that cause airway constriction and wheezing.