Micro-RNA Profiling and Cardiovascular Effects of Traffic Particle Exposure

摘要 空气污染是美国和世界范围内一个主要的公共卫生问题。暴露于空气颗粒物(PM) 众所周知，空气动力学直径2.5？m(PM2.5)会增加心血管疾病的发病率和 死亡率。吸入PM2.5可诱导全身促炎反应和氧化应激，这两个主要因素 心血管疾病(CVD)途径。高接尘工人外周血白细胞基因表达谱研究 受试者已经发现全身炎症反应是通过广泛的基因表达来启动的。 但调控基因表达变化的机制在很大程度上还没有被探索。MicroRNAs(MiRNAs) 是新出现的小RNA分子，它们是基因表达的关键调控因素。炎症和 氧化应激已被证明可以改变miRNA的表达，这可以由它们的编码基因控制 DNA甲基化状态。我们的初步数据显示，PM2.5暴露改变了表达水平 在高度PM暴露的人群中，血液白细胞中某些miRNA的含量。我们假设PM暴露于- 诱导的氧化应激和炎症反应可能导致血白细胞miRNA表达的变化 来调节基因表达谱。基因表达的改变可能会导致某些特定的变化 循环生物标记物和心血管生理学有助于心血管疾病的发展。 我们建议使用北京卡车司机空气污染研究(BTDAS)的数据来检验这些假设，我们的 最近在北京完成了一项研究，中国是世界上污染最严重的城市之一。多亏了特别 由意大利科学研究部资助，BTDAS在北京会议前不久进行 2008年奥运会(2008年6月15日至7月27日)。招募了两组受试者，即60名卡车司机 (高暴露)和60名室内工作人员(低暴露)。我们收集了个人PM2.5及其有毒金属 在工作时间通过空气监测仪获得暴露数据，通过Holter监测仪获得连续的EKG数据，以及血液 样品在工作结束时，在两个独立的工作日，间隔1-2周。我们建议进行一项 1)通过执行一项辅助研究来确定PM2.5及其有毒金属相关miRNA表达特征 使用高定量下一代测序技术无偏筛选miRNAs；2)检查 MiRNA的表达与编码基因甲基化状态有关；3)确定PM是否与 MiRNA签名与使用我们已经测量的血浆数据的CVD测量相关联 炎症和凝血标志物、血压和心电图。鉴于普通公众无处不在的 暴露在空气污染中，这项研究具有很高的意义。这项研究旨在充分利用 独特的标本库以及以前收集的数据和审查的措施，以潜在地 确定将空气污染与心血管疾病联系起来的新机制，从而有可能确定重要的 心血管疾病的预防策略。

Abstract Air pollution is a major public health concern in the US and worldwide. Exposure to air particulate matter (PM) with an aerodynamic diameter <2.5 ¿m (PM2.5) is well known to increase cardiovascular incidence and mortality. Inhaled PM2.5 induces systemic pro-inflammatory response and oxidative-stress, two major cardiovascular disease (CVD) pathways. Blood leukocyte gene expression profiling in highly PM-exposed subjects has revealed that systemic inflammatory responses are initiated through extensive gene expression shifts but mechanisms regulating the gene expression changes are largely unexplored. MicroRNAs (miRNAs) are small RNA molecules that have newly emerged as key regulators of gene expression. Inflammation and oxidative stress have been shown to alter miRNA expression, which can be controlled by their encoding gene DNA methylation status. Our preliminary data have shown that PM2.5 exposure changed the expression levels of certain miRNAs in blood leukocytes in a highly PM-exposed population. We hypothesize that PM exposure- induced oxidative stress and inflammatory response may cause blood leukocyte miRNA expression changes that regulate gene expression profiles. Gene expression alterations may then cause certain changes in circulating biomarkers and cardiovascular physiology to favor CVD development. We propose to test these hypotheses using data from the Beijing Truck Driver Air Pollution Study (BTDAS), our recently completed study in Beijing, China, one of the most polluted cities in the world. Thanks to special funding by the Italian Ministry of Scientific Research, the BTDAS was conducted shortly before the Beijing 2008 Olympic Games (June 15 to July 27, 2008). Two groups of subjects were recruited, i.e., 60 truck drivers (high exposure) and 60 indoor workers (low exposure). We collected personal PM2.5 and its toxic metal exposure data via air monitors and continuous EKG data via Holter monitors during their work hours, and blood samples at the end of work, on two independent work days with 1-2 week intervals. We propose to conduct an ancillary study to 1) identify PM2.5- and its toxic metal-related miRNA expression signatures by performing an unbiased screening of miRNAs using highly quantitative Next Generation Sequencing; 2) examine whether miRNA expression is associated with encoding gene methylation status; 3) determine whether PM-related miRNA signatures are associated with CVD measures using our already measured data on plasma inflammatory and blood clotting markers, blood pressure and EKG. Given the general public's ubiquitous exposure to air pollution, this research is of high significance. This study is designed to take full advantage of the unique specimen repository as well as previously collected data and examined measures to potentially identify novel mechanisms linking air pollution with CVD, and thus provide the potential to identify important CVD preventive strategies.