Arrestin Selectivity for GPCRs in Airway Smooth Muscle

描述(由申请人提供)：阻滞剂通过破坏G蛋白偶联受体-G蛋白的相互作用和“阻断”受体的信号传递能力来调节许多G蛋白偶联受体(GPCRs)。虽然利用细胞过表达系统的研究已经有相当多的证据表明了抑制素的重要性，但我们对arrestin在生理系统中对内源性GPCRs的调控的了解是有限的。我们建议表征抑制素调节气道平滑肌(ASM)GPCRs的能力和选择性，最终目标是靶向抑制素，以此作为提高吸入β-激动剂治疗哮喘和慢性阻塞性肺疾病的疗效的一种手段。根据本文提供的初步数据，我们假设可以利用GQ和Gs偶联受体对β-arrestin-1和β-arrestin-2选择性的差异来增强β-激动剂松弛其他GPCRs收缩的ASM的能力。AIMS 1和2将建立β-arrestin-1和beta-arrestin-2对介导ASM收缩(包括毒鼠碱、半胱氨酸白三烯和组胺受体)或松弛(β2-肾上腺素和前列腺素E2受体)的GPCRs的选择性。AIM 1将利用分子和遗传方法在来自人类和小鼠的ASM细胞和组织中靶向β-arrestin-1和/或β-arrestin-2。Arrestin抑制或基因去除对GPCRs的ASM信号和收缩特性的影响将被评估。目的2将进行补充生理测量，以确定arrestin基因在体内对ASM收缩和松弛的调节作用。总而言之，这些研究将提供ASM中arrestin选择性的高度机械性分析，并确定差异调节ASM收缩或松弛的受体的方法。 公共卫生相关性：这些研究试图确定抑制呼吸道平滑肌中的一个关键调节分子的有用性(作为哮喘治疗)。了解β-arrestin-1或β-arrestin-2是如何调节平滑肌受体的，可能会让我们提高药物放松平滑肌的能力，同时抑制导致呼吸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.