Air Pollution and Microvascular Dysfunction: Leukocyte-Dependent NAD(P)H Oxidase

描述(由申请人提供) 流行病学研究表明，细颗粒物(PM2.5)与急性心血管事件之间存在关联。虽然目前还不清楚导致血管对吸入PM2.5反应的确切机制(S)，但很明显，这些反应可以在暴露后几周内发生。为了研究PM2.5可能通过短期暴露调节炎症和血管紧张性的机制，研究人员将使用真实世界环境PM2.5暴露在相关动物模型中调查这些反应。因此，他们假设暴露在环境PM2.5中8周通过单核/巨噬细胞NAD(P)H依赖的活性氧物种(ROS)的产生而诱导全身微血管炎症和功能障碍，内皮型一氧化氮在这些反应的调节中发挥关键作用。研究人员计划在适当的动物模型系统中系统地检验这一假设，该模型系统将包括转基因和组织特异性条件性基因敲除小鼠，通过使用通用的环境暴露系统，通过Cre-lox技术进行。在第一个具体目标中，他们将研究FVBN小鼠和内皮型一氧化氮合酶(ENOS)基因敲除小鼠暴露于PM2.5 8周的影响，并检测白细胞和血管反应以及生殖主微循环中超氧化物歧化的产生。在第二个特定目标中，研究人员将通过流式细胞术、活体显微镜和实时定量PCR检测PM2.5暴露后在c-FMS启动子控制下表达增强型黄色荧光蛋白(YFP)的小鼠单核/巨噬细胞NAD(P)H氧化酶的激活情况。在最终的特定目标中，他们将研究PM2.5暴露对缺乏NAD(P)H氧化酶关键胞浆成分(p47Phox-/-或gp91Phox-/-)和组织特异性(内皮或单核/巨噬细胞谱系)、条件性基因敲除小鼠模型的微循环中NAD(P)H氧化酶介导的ROS介导的单核细胞反应的影响。还将进行PM2.5的主成分分析，以阐明哪些与来源相关的成分与生物反应最密切相关。这项研究有望提供PM2.5暴露与全身炎症反应之间的联系，并将为空气污染暴露与心血管不良效应之间的联系提供细胞和分子基础。

DESCRIPTION (provided by applicant) Epidemiological studies have demonstrated an association between fine particulate matter (PM2.5) and acute cardiovascular events. While the precise mechanism(s) that result in transduction of responses to inhaled PM2.5 in the vasculature are currently not well understood, it is clear that these responses can occur within a few weeks of exposure. To investigate the mechanisms by which PM2.5may modulate inflammation and vascular tone with short-term exposure, the researchers will investigate these responses in relevant animal models using real world ambient PM2.5 exposure. Accordingly, they hypothesize that exposure to ambient PM2.5 for 8 weeks induces systemic microvascular inflammation and dysfunction through monocyte/macrophage NAD(P)H dependent reactive oxygen species (ROS) generation and that endothelial nitric oxide plays a pivotal role in modulation of these responses. The investigators plan to examine this hypothesis systematically in appropriate animal model systems that will include genetically modified and tissue-specific conditional gene knockout mice via Cre-lox technology using a versatile ambient exposure system. In the first specific aim, they will investigate the effect of 8-week exposure to PM2.5 in FVBN mice and endothelial nitric oxide synthase (eNOS) knockout mice and examine leukocyte and vascular responses and superoxide production in cremasteric microcirculation. In the second specific aim, the investigators will determine the activation of monocyte/macrophage NAD(P)H oxidase in mice expressing enhanced yellow fluorescent protein (YFP) under the control of c-fms promoter after PM2.5 exposure by flow cytometry, intravital microscopy, and real time PCR. In the final specific aim, they will investigate the effect of PM2.5 exposure on NAD(P)H oxidase derived ROS-mediated monocyte response in the microcirculation in the mice deficient in a critical cytosolic component of NAD(P)H oxidase (p47phox-/- or gp91phox-/-) and tissue specific (endothelium or monocyte/macrophage lineage), conditional gene knockout mice models. Principal component analysis of PM2.5 will also be performed to elucidate which source-related components are most closely associated with biological responses. This study is expected to provide the link between PM2.5 exposure and systemic inflammatory response, and will provide a cellular and molecular basis for the association of adverse cardiovascular effects with air pollution exposure.