Combustion-Generated EPFRs: Assessing Cardiovascular Risks of Exposure

项目摘要/摘要：项目2 颗粒物(PM)一直与心肺和心血管疾病的死亡率有关。尽管 关于暴露的风险，人们对PM介导的毒性的潜在机制知之甚少。我们的中心有 结果表明，有害有机物或受污染土壤的热处理(TT)产生的PM排放 超级基金网站产生环境持久性自由基(EPFR)。EPFR是一种独特的粒子- 能够在生物系统中进行氧化还原循环以产生活性氧物种(ROS)的污染物系统。 EPFR存在于受污染的超级基金土壤和工业化超级基金场地附近的空气PM中。我们的 之前的超级基金项目侧重于EPFR在调节心脏功能和疾病中的作用。虽然 吸入EPFR会降低基础心功能，我们发现这些影响是继发性的 肺血管阻力的变化。这些血管效应背后的机制(S)尚不清楚； 然而，我们的初步数据表明，EPFR介导的芳烃受体(AhR)激活 在肺上皮细胞中导致血管活性因子的释放可能起重要作用 病理生理作用。我们的中心假设是EPFR介导的AhR在空气-血液中的激活 血管活性物质的界面和动员导致肺和肺功能的激活/功能障碍 全身血管系统，导致心血管疾病。为了验证这一假设，《特定目标1》将测试 EPFR介导的肺上皮细胞AhR激活是否与肺活量增加有关 压力和舒张期充盈减少是EPFR引起的心功能不全的基础。在建立了 血管系统作为损伤的部位，特异靶2将通过以下方式阐明血管损伤的细胞机制 测试EPFR是否通过激活AhR而导致血管功能障碍。在这两个目标中，控制产仔 小鼠和AHR缺陷的小鼠，特别是在肺泡II型上，将亚慢性暴露于EPFR，非 EPFR PM，或使用最近设计的吸入系统过滤的空气。米勒压力-容量导管将是 用于测量暴露小鼠的左心功能和肺动脉压。遥测设备 将被用来记录血压。内皮依赖性血管反应性以及两者的标志物 将对内皮功能障碍和激活情况进行评估。具体目标3将确定一个假定的配体促进 EPFR诱导的AhR激活并检测该代谢物是否与EPFR介导的血管相关 功能障碍。与项目1合作，这一目标将使用新的质谱学方法来确定 并鉴定EPFR诱导的可能作为内源性AhR激动剂的脂质氧化产物，从而 我们可能会将这些代谢物的组织和血液水平与血管功能障碍联系起来。完成这些工作 AIMS将提供重要的新数据，将EPFR介导的上皮细胞氧化应激，AhR激活， 和心血管疾病。这些信息对于评估居住在工地附近的人的风险至关重要。 使用TT技术修复超级基金或其他危险废物。

Project Summary/Abstract: Project 2 Particulate matter (PM) is consistently associated with cardiopulmonary and cardiovascular mortality. Despite the risk of exposure, little is known about the mechanisms underlying PM-mediated toxicity. Our Center has shown that PM emissions from the thermal treatment (TT) of hazardous organics or contaminated soils at Superfund sites produce environmentally persistent free radicals (EPFRs). EPFRs are a unique particle- pollutant system capable of redox cycling to generate reactive oxygen species (ROS) in biological systems. EPFRs are present in contaminated Superfund soils and airborne PM near industrialized Superfund sites. Our prior Superfund project focused on the role of EPFRs in modulating cardiac function and disease. Although inhalation of EPFRs decreased baseline cardiac function, we found that these effects were secondary to changes in pulmonary vascular resistance. The mechanism(s) underlying these vascular effects are unknown; however, our preliminary data suggest that EPFR-mediated activation of the aryl hydrocarbon receptor (AhR) in pulmonary epithelial cells resulting in the release of vasoactive factors may play an important pathophysiological role. Our central hypothesis is that EPFR-mediated activation of AhR at the air-blood interface and mobilization of vasoactive mediators leads to activation/dysfunction of the pulmonary and systemic vasculature, resulting in cardiovascular disease. To test this hypothesis, Specific Aim 1 will test whether EPFR-mediated activation of the AhR in lung epithelium is responsible for the increase in pulmonary pressure and decreased diastolic filling that underlies EPFR induced cardiac dysfunction. After establishing the vasculature as the locus of injury, Specific Aim 2 will elucidate the cellular mechanisms of vascular injury by testing whether EPFRs induce vascular dysfunction via activation of the AhR. In both aims, control littermate mice and mice deficient in AhR specifically in alveolar type II will be exposed subchronially to EPFRs, non- EPFR PM, or filtered air using a recently designed inhalation system. Millar pressure-volume catheters will be used to measure left ventricular function and pulmonary arterial pressure in exposed mice. Telemetry devices will be used to record blood pressure. Endothelium-dependent vascular reactivity, as well as markers for both endothelial dysfunction and activation, will be assessed. Specific Aim 3 will identify a putative ligand promoting EPFR-induced AhR activation and test whether this metabolite is associated with EPFR-mediated vascular dysfunction. In collaboration with Project 1, this aim will use novel mass spectrometry approaches to identify and characterize EPFR-induced lipid oxidation products that may serve as endogenous AhR agonists so that we may correlate tissue and blood levels of these metabolites with vascular dysfunction. Completion of these Aims will provide important new data linking EPFR-mediated oxidative stress in epithelial cells, AhR activation, and cardiovascular disease. This information is critical for assessing risks to those living in proximity to sites using TT technologies to remediate Superfund or other hazardous wastes.