典型环境污染物与超细颗粒低水平联合暴露的心血管毒性及机制研究

The atmospheric particle pollution is very serious in China, especially ultrafine particle (PM0.1). However, up to nowthere has been no study on the joint action of ultrafine particles and pollutants and its relationship with cardiovascular disease. This project would combine the laboratory and cardiovascular disease sample research together, construct and systemic characterize the joint exposure system of ultrafine particles and typical environmental pollutants; determine the joint toxicity and its type under the effective-level and low-level exposure; investigate the oxidative damage, DNA damage, cell cycle, apoptosis, autophagy, inflammation and pathological changes of cardiovascular system induced by the joint exposure system in vitro and in vivo, and determine the cardiovascular toxicity; carry out the high throughput screening using the techniques of toxicogenomics and explore its related mechanisms; develop the case-control study and disease susceptibility research of population cardiovascular disease; analyze the envrionmental genetic interaction during the process of cardiovascular disease developing; and screen out the exposure biomarkers and disease biomarkers in early stage related to the cardiovascular disease. Based on the results acquired from the lab and population research, the mode of action (MOA) and human relevance framework (HRF) would be done, and the correlation between joint exposure and human cardiovascular disease would be analyzed comprehensively. The research achievement would provide the scientific basis for the atmospheric environmental management, the etiology research and the effective prevention and control of cardiovascular disease.

我国大气颗粒污染严重，超细颗粒（PM0.1）危害尤为突出，但目前超细颗粒与污染物联合作用及其与心血管疾病的关系尚无研究。本项目将实验室和人群心血管疾病样本研究相结合，构建超细颗粒与典型环境污染物的联合暴露体系并进行系统表征；确定体系在效应水平和低水平暴露的联合作用及类型；在体外和体内条件下研究联合暴露体系致心血管系统氧化损伤、DNA损伤、细胞周期、细胞凋亡、自噬、炎症反应和病理改变，确定联合体系心血管毒性效应；采用毒物基因组学技术进行高通量筛查和相关机制研究；开展人群心血管疾病病例对照研究和疾病易感性研究；分析心血管疾病形成过程中的环境遗传交互作用；筛选心血管疾病相关效应生物标志和疾病早期生物标志。根据实验室和人群研究结果，进行心血管疾病毒作用模式（MOA）和人类相关性框架（HRF）研究，综合分析联合暴露与人类心血管疾病的关联，为大气环境治理和心血管疾病病因学研究及有效防治提供科学依据。

我国大气颗粒污染十分严重，大气颗粒物污染与心血管疾病的发病率和死亡率相关，小于100nm的超细颗粒对心血管疾病的影响更为显著，但目前超细颗粒与污染物低剂量联合作用及其与心血管疾病的关系尚未见相关报道。本研究首先构建超细颗粒与典型环境污染物的联合暴露体系并进行系统表征，通过红外线光谱法、热失重法、液体表面张力检测发现超细颗粒（纳米SiO2和炭黑颗粒）与环境污染物（Pb(AC)2，MeHg，B[a]P）联合暴露后，出现明显的吸附作用，说明联合暴露体系较为稳定，存在相互作用。体外研究发现，典型环境污染物与超细颗粒联合暴露，对心肌细胞和血管内皮细胞造成的损伤更明显，加剧氧化损伤、DNA 损伤、细胞周期、细胞凋亡和炎症反应，其联合作用类型表现为相加或协同作用。体内研究发现，典型环境污染物与超细颗粒联合暴露可加剧对心血管系统的损伤作用，诱发血液高凝状态，改变血管内皮细胞和心肌细胞超微结构，心肌细胞线粒体损伤，引起心肌损伤，从而导致心脏功能下降。采用斑马鱼模型，课题组首次报道纳米SiO2与B[a]P和MeHg联合暴露可增强对斑马鱼的心血管毒性，表现为引起ROS产生和氧化应激、激活炎症反应、损伤血管内皮细胞、引起血液高凝状态。纳米SiO2与环境典型污染物B[a]P联合作用可引起血管内皮功能紊乱，上调AP-1/c-Jun上调外源性凝血因子TF的表达。芯片分析表明，环境污染物与超细颗粒联合暴露可以导致斑马鱼胚胎mRNA与miRNA的表达谱改变。Dynamic-gene-network分析显示，联合暴露涉及心血管毒性主要基因包括Stxbp1a，Celf4，Ahr1b，Bai2，Ndfip2和Gsk3b。通过对miRNA-pathway-network的研究发现，miR-34a，miR-181c，miR-129-5p，miR-221在联合暴露的心血管毒性中具有重要作用。此外，基于尿液代谢组的人群定组干预研究显示，7种代谢物与心血管疾病有密切相关性。代谢通路分析表明，三羧酸循环在男性和女性中都受到显著影响。说明大气颗粒物干扰了正常人群的机体能量代谢，引发不良心血管效应。本研究综合分析了联合暴露与人类心血管疾病的关联，为大气环境治理和心血管疾病防治提供科学依据。