大气细颗粒物暴露导致慢阻肺的暴露组学与系统生物学研究

Fine particles (e.g., PM2.5) are important components in air pollution among major Chinese cities, and attracted increasing concerns regarding to their adverse impact on human health, especially the respiratory systems. Chronic obstructive pulmonary disease (COPD) is one of the four major chronic diseases defined by the World Health Organization (WHO), associated with high morbidity and mortality rate. In China, COPD affects 10% of adult population and could be closely related to air pollution exposure. However, the etiological mechanism that inhaled air fine particles damage respiratory organs and induces COPD remains unclear. The proposed project consists four inter-connect aims. (1) Ambient fine particles are a complex mixture of various components, and the toxicity is primarily governed by the composition and concentration of the composites. Previous epidemiology studies mainly focus on overall pollutant concentration or a rather coarse component dissection. In this aim, we collect ambient air sample during exposure experiments (ie, human subjects longitudinal cohort and animal models), and apply state-of-art methods to quantify the fine particle components in a great detail. By these means, we derive the granular dose-response relationship between PM2.5 exposure and adverse respiratory consequences. (2) Due to lack of adequate tools, previous environmental epidemiology studies were done at the community average level, or crudely assessed individual exposure level. Herein, we introduce an integrated solution combined portable device and cloud computing to real time monitor and record the amount of inhaled PM2.5 at individual level. In the end, we obtain accurate cumulative expose dosage and exposure pattern and relate to lung function and molecular profiles. (3) We will carry out exposure experiments on human subjects and animal models in parallel. For human, we organize an observational longitudinal study in Shanghai consists of COPD patients and healthy control exposed to ambient air. Animal models will be exposed to Shanghai ambient air, simulated air pollutant, and filtered clean air. Lung function measurement and specimen collection will be conducted at multiple time points during the experiment. (4) We will generate –omics data for airway microbiome, interleukin profile and transcriptome levels. In mouse study, airway and lung tissue will be collected after exposure experiments for –omics profiling; in human cohort study, sputum specimen will be collected at each follow-up visit for microbiome and interleukin profiling. We will also leverage existing transcriptome data cumulated by our group on 600 COPD and 800 non-COPD subjects, where whole genome transcriptome and genotype data are available. On the existing human lung study cohort, we defined the quantitative trait loci (eQTL), co-expression modules and directed networks. The genes, pathways and modules which shifted from non-COPD states to COPD states were identified, termed as COPD molecular signatures. We will apply systems biology approach to compare and overlay omics data generated in the current study to our existing COPD signature and pinpoint the genes and pathways that response to PM2.5 exposure and in turn lead to airway damage and COPD. The key driver analysis (KDA) will discover key regulatory gene/interleukin that play central role in the pathways or co-expression modules. We will also explore for sputum microbiome or interleukin biomarker that indicate immune response, airway damage and COPD progression.

慢性阻塞性肺疾病（COPD）发病机制与吸入细颗粒物(PM2.5)相关。目前，亟需阐明PM2.5中导致COPD的主要组分及致病的毒理机制。本项目有密切相关的四部分。 (一). PM2.5组分复杂、本申请利用大气环境化学方法，开展效应导向的细颗粒物组分鉴定、甄别。在精细组分的水平上，研究PM2.5呼吸系统毒理机制和生物分子组的响应。 (二). 部署本团队开发的个体水平PM2.5暴露检测系统，开展基于个体水平暴露的环境流行病学研究。 (三). 在PM2.5精细组分和个体水平暴露的基础上，进行动物模型暴露试验和流行病定群研究，观测暴露后的肺功能变化，收集呼吸系统组织样本。 (四). 采集海量数据。运用系统生物学方法，分析整合高维度数据，揭示大气细颗粒物毒性组分诱发呼吸系统炎症，器官功能紊乱和COPD的细胞和分子机制；建立PM2.5暴露引发慢阻肺的细胞、组织、和分子水平的评价方法。

大气细颗粒物污染是我们现阶段突出的环境问题，也是慢阻肺的重要病因。然而由于缺乏长期全天候监测受试者个体暴露水平的方法，加之可吸入颗粒物组分复杂，使我们对各个组分的健康效应知之甚少；并且在分子组学层面，PM2.5对慢阻肺相关组织中各种生物分子的影响进而导致慢阻肺的致病机理，研究仍然不足。针对上述挑战, 本课题按计划顺利完成了四部分工作。.（1）本项目创新开发了个体水平大气污染物吸入量测量系统Bio3Air，以及窄带物联网通信的室内空气污染物监测仪器（Bio3Gear V2）。详尽的评估显示，Bio3Air具有很高的时间和空间分辨率，数据可重复性，和数据准确性。.（2）课题在上海建立了健康志愿者队列和慢阻肺风险队列，测量PM2.5暴露量，并收集肺功能表型和痰液样本信息。使用高通量测序的实验方法，首次在人群队列中揭示了PM2.5对气道微生物群落的影响，并解析了呼吸道微生物与呼吸功能之间的联系。.（3）课题建立了包含颗粒物发生、颗粒物稀释、暴露箱以及检测和控制设备的一套完备的小鼠暴露实验系统，并完成PM2.5中主要无机盐组分（铵盐、硫酸盐、硝酸盐）的动物暴露实验。本研究首次实验证实了，在我国大气常见浓度下，硝酸盐颗粒物暴露对呼吸系统产生显著损伤，而铵盐和硫酸盐颗粒物的效应则弱得多。在相同浓度下，PM2.5硝酸盐组分对幼年小鼠的损伤，远远大于对成年小鼠的损伤。.（4）开展大气污染健康效应领域首个单细胞RNA测序研究，揭示了硝酸盐颗粒物暴露干扰肺组织基因表达的剂量-效应关系，被干扰的基因富集于四条生物功能通路：生物节律，鞘磷脂代谢，免疫反应和溶酶体，本研究在肺基因表达谱、致病通路、共表达网络、肺组织细胞组成类型和单细胞转录组水平上，发现了了硝酸盐颗粒物暴露导致慢阻肺的可能致病机制。.本项目弥补了环境流行病学研究方法的缺失，收集多个层次的暴露和生物数据，揭示我国典型区域大气细颗粒物无机盐组分损伤呼吸功能的效应，以及组织、细胞和分子水平的治病机制。