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

与交通有关的空气污染包括柴油机废气中的多环芳烃 (PAH)与哮喘有关的疾病吸入性β 2-肾上腺素能激动剂与膜结合的β 2- 气道上皮细胞和平滑肌细胞上的肾上腺素能受体（p2 AR）引起气道扩张。 为这一应用产生的初步数据表明，柴油机排气衍生的多环芳烃混合物 DDPAH对正常小鼠和卵白蛋白诱导的过敏性哮喘小鼠p2 AR介导的气道扩张有抑制作用 哮喘体外研究表明，DDPAH减弱气道上皮和平滑肌中的p2 AR功能， 肌肉细胞这些新的发现使我们假设交通相关的PAH可能会阻碍p2 AR 介导的哮喘患者的气道松弛。这一假设提出了一种新的模式，空气污染物不 这只会加重儿童哮喘，但会降低对标准治疗的反应性。为了验证这一假设， 针对交通相关PAH（TR-PAH）对气道p2 AR功能的影响提出了3个目标。 目的1：确定交通相关的多环芳烃是否影响气道上皮细胞p2 AR的表达和功能 体外细胞原代小鼠气管上皮细胞（MTE）和人气道上皮细胞将用 DDPAH或PAH混合物的环境相关浓度与儿童暴露量相匹配 在项目1（CCCEH-PAH）中描述的CCCEH队列中，在评估p2 AR及其信号之前 转导途径 目的2：确定交通相关的多环芳烃是否影响气道平滑肌细胞的p2 AR功能， 体外人气道平滑肌细胞将暴露于环境相关浓度的 DDPAH或CCCEH-PAH，然后评估p2 AR及其信号转导通路。 目的3：确定TR-PAH是否改变子宫内和生命早期的气道p2 AR功能 暴露？在这个目标的实验将测试是否长期暴露于DDPAH或CCCEH-PAH改变 p2 AR介导的幼鼠气道反应性降低。这些实验将利用小鼠模型 在子宫内和生命早期的暴露，模型的哮喘易感性的窗口正在研究， 项目1、2和3。这些实验将在正常小鼠、过敏性哮喘小鼠 （卵清蛋白免疫和再激发）、具有p2 AR靶向缺失的小鼠和具有p2 AR靶向缺失的小鼠。 上皮细胞p2 AR功能的中断。 这些目标中的重点研究包括环境相关的PAH暴露、分子 工具，临床相关的细胞系，基因工程小鼠，和基因转移，以产生模型， 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设。这些 实验补充了整个DISCOVER项目中概述的研究，为以下方面提供了新的见解： 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.