载铅超细炭黑在肺细胞内铅的释放规律及其分子、细胞和动物层面上毒性效应与机理的研究

Because of the high frequency of the heavy haze, research into the released toxic cominponents within the body, the toxic effects and mechanisms of atmospheric ultrafine particles (UFPs) has attracted great attention from the environmentalists, the medical workers and even the common people around the world, which has also become an importantly advanced research field. Considering the complexity of the constituents in the UFPs and the limitation of the current research methods and technologies, there is still a little knowledge about their toxicity effects and mechanisms induced by every released components and their coeffect. This project aims to systematically study the lead detection method and lead released rule from the lead loaded ultrafine carbon black (UFCB) in various diameters, doses, and amounts of lead loaded within the cell, and to investigate the toxicity contribution of every released component and their separate mechanisms of toxic effects on the lung fibroblast and alveolar type II epithelial cell. Thus, we can evaluate the effects and mechanisms of oxidative stress, signal pathway, and pathological changes such as the pneumonia caused by the different particle components on the molecular, cellular and animal level. The objective of this work is to precisely understand the toxic effects and mechanisms of lead loaded UFCB to the lung, and provide new scientific evidence for the research programs that focus on the development of the accurate evaluation system of the mutual toxic effects and mechanisms on the exposure of diverse components in UFPs.

在雾霾事件频繁爆发的形势下，大气超细颗粒物在体内释放毒性组分、毒性效应与机理的研究已成为世界各地环境、医学工作者乃至百姓极为关注的、具有重要价值的前沿课题。由于大气颗粒物成分复杂，且受研究方法和技术的限制，人们对颗粒物中各组分共同产生毒性效应与机理的认识十分有限。本项目致力于系统研究不同粒径、不同剂量、不同载铅量的超细炭黑在细胞内释放铅的检测及铅的释放规律，各成分分别对肺成纤维细胞和肺泡II型上皮细胞毒性效应贡献的份额与机理；从分子、细胞和动物层面上评价其中各成分诱发氧化应激、信号通路和肺炎等病理变化的效应与机理。本研究的目标是准确理解载铅超细炭黑复合污染对肺毒性效应的过程与机理，为发展精确评估超细颗粒物各毒性组分共同诱发毒性效应与机理的研究方案提供新的科学依据。

本项目实施前大气中超细颗粒物（UFPs）及其联合组分的毒性效应和机理评价缺少准确、科学的研究方法，超细炭黑（UFCB）粒径和剂量毒性效应以及载铅UFCB在动物、细胞和分子层面上尤其是肺细胞内的生物学毒性效应有待阐明。基于上述科学问题，本项目进行了如下研究：（1）动物水平上证明了UFCB可以通过诱发斑马鱼氧化应激效应对斑马鱼的基因表达水平和生长发育产生影响，细胞水平上发现UFCB可进入小鼠原代肝细胞内部并诱发细胞的氧化应激和基因损伤，并在分子水平上阐明了超细炭黑对重要抗氧化蛋白（SOD、LYZ和TF）和DNA分子的结构和功能造成影响的机制；（2）构建了肺细胞内载铅UFCB诱发氧化应激、细胞周期变化和细胞凋亡的毒性规律体系，并以肝、肾、脾细胞作为靶向细胞，阐明了UFCB负载铅后在细胞内的联合毒性机制；（3）UFCB的粒径毒性效应研究中通过验证粒子细胞摄取量和分散性程度是决定UFCB细胞和分子毒性的关键因素，构建了细胞内外抗氧化蛋白功能随UFCB粒径变化的规律模型。.本研究为多组分UFPs的毒性效应评价和机制研究提供了基础数据和科学的研究方法，为不同粒径UFCB在工程应用中的规避和替代提供了理论依据，完成了预期的研究目标。