Effect of Traffic-Related Pollutants on Airway Beta2-Adrenergic Receptors

与交通相关的空气污染包括柴油发动机尾气中的多环芳烃 (PAH)与哮喘有关。吸入(32-肾上腺素能激动剂与膜结合的p2- 呼吸道上皮细胞和平滑肌细胞上的肾上腺素能受体(P2AR)可引起呼吸道扩张。 为这一应用产生的初步数据表明，柴油尾气产生的多环芳烃混合物 (DDPAH)抑制p2AR介导的正常小鼠和卵白蛋白致敏小鼠的气道扩张 哮喘。体外研究表明，DDPAH减弱了呼吸道上皮细胞和光滑细胞的p2AR功能 肌肉细胞。这些新的发现使我们假设与交通相关的PAH可能阻碍了p2AR 哮喘患者的介导性呼吸道松弛。这一假设提出了一种新的范式，即空气污染物不会 只会加重儿童哮喘，但会降低对标准治疗的反应性。为了检验这一假设，我们 针对交通相关PAH(TR-PAH)对气道p2AR功能的影响提出3个目标。 目的1：确定交通相关多环芳烃是否影响呼吸道上皮细胞p2AR的表达和功能 体外培养的细胞。原代小鼠气管上皮细胞(MTE)和人呼吸道上皮细胞将被 与儿童暴露相匹配的与环境相关的DDPAH浓度或PAH混合物 在评估p2AR及其信号之前，在项目1(CCCEH-PAH)中描述的CCCEH队列中 转导途径。 目的2：确定交通相关多环芳烃是否影响大鼠气道平滑肌细胞的p2AR功能。 体外培养。人体呼吸道平滑肌细胞将暴露于与环境相关的浓度 DDPAH或CCCEH-PAH在评估p2AR及其信号转导途径之前。 目的3：确定tr-PAHs是否会改变宫内和生命早期的呼吸道p2AR功能 曝光？这个目的的实验将测试长期接触DDPAH或CCCEH-PAH是否会改变 P2AR介导的幼鼠呼吸道反应性降低。这些实验将利用小鼠模型 宫内和早期暴露的模型的哮喘易感性窗口正在调查 项目1、2和3。这些实验将在正常小鼠、过敏性哮喘小鼠身上进行 (卵蛋白免疫和再激发)，靶向缺失p2AR的小鼠，以及 上皮细胞p2AR功能中断。 这些目标中的重点研究包括与环境相关的多环芳烃暴露、分子 工具，临床相关的细胞系，基因工程小鼠，以及基因转移，以产生将 请允许我们提出一个关于空气污染物和哮喘相互作用的新假说。这些 实验补充了整个发现项目中概述的研究，以提供新的见解 常见的空气污染物如何影响儿童的肺部健康。

Traffic related air pollution includes diesel engine exhaust derived polycyclic aromatic hydrocarbons (PAH) that have been linked with asthma. Inhaled (32-adrenergic agonists engage membrane bound p2- adrenergic receptors (p2AR) on airway epithelial and smooth muscle cells to cause airway dilation. Preliminary data produced for this application indicate that a diesel exhaust derived mixture of PAHs (DDPAH) impede p2AR mediated airway dilation in normal mice and mice with ovalbumin-induced allergic asthma. In vitro studies indicate that DDPAH attenuates p2AR function in airway epithelial and smooth muscle cells. These new findings caused us to hypothesize that traffic-related PAH may impede p2AR mediated airway relaxation in asthmatics. This hypothesis suggests a new paradigm where air pollutants not only worsen childhood asthma but diminish responsiveness to standard therapy. To test this hypothesis we are proposing 3 aims regarding the effect of traffic-related PAH (TR-PAH) on airway p2AR function. Aim 1: Determine if traffic-related PAHs affect p2AR expression and function in airway epithelial cells in vitro. Primary mouse tracheal epithelial (MTE) and human airway epithelial cells will be treated with environmentally relevant concentrations of a DDPAH or a mixture of PAH that matches exposures of children in the CCCEH cohort described in project 1 (CCCEH-PAH) prior to assessment of the p2AR and its signal transduction pathway. Aim 2: Ascertain if traffic-related PAHs affect p2AR function in airway smooth muscle cells in vitro. Human airway smooth muscles cells will be exposed to environmentally relevant concentrations of DDPAH or CCCEH-PAH prior to assessment of the p2AR and its signal transduction pathway. Aim 3: Determine if TR-PAHs alter airway p2AR function following in utero and early life exposures? The experiments in this aim will test if prolonged exposure to DDPAH or CCCEH-PAH alters p2AR-mediated reductions in airways reactivity in young mice. These experiments will utilize mouse models of in utero and early-life exposure that model the windows of asthma susceptibility being investigated in projects 1, 2, and 3. These experiments will be conducted in normal mice, mice with allergic asthma (ovalbumin immunization and rechallenge), mice with targeted deletions of the p2AR, and mice with interruption of epithelial cell p2AR function. The focused studies within these aims incorporate environmentally relevant PAH exposures, molecular tools, clinically relevant cell lines, genetically engineered mice, and gene transfer to generate models that will allow us address a novel hypothesis regarding the interaction of airborne pollutants and asthma. These experiments complement the studies outlined throughout this DISCOVER project to provide new insights into how common air pollutants affect children's lung health.