应用同步辐射技术研究PM2.5在呼吸道细胞内的迁移转化及其诱导细胞氧化损伤的分子作用机制

It is well acknowledged that the lung, in particular pulmonary epithelial cells, represents a primary biological target for injury arising from inhalation exposure to fine particulate matter (PM2.5, aerodynamic diameter <2.5 µm). Harmful environmental pollutants are released into the pulmonary surfactant and attach the pulmonary epithelial cells. Exposure of endothelial cells from the airways and alveoli to pollutants induces a series of cytotoxic effects, such as reactive oxygen species (ROS) generation and cytokines release, which are responsible for the inflammatory responses. However, the cytotoxic effects of PM exposure that lead to oxidative damage in lung epithelial cells have been extensively demonstrated. The aim of this project is going to investigate the potential interactions between immigration and transformation of PM2.5 and oxidative damage to further appreciate the mechanism of cytotoxicity in human respiratory epithelial cells using synchrotron radiation techniques and cellular molecular methods. Firstly, the chemical components and their species of PM2.5 will be carried out using micro-focus x-ray fluorescence spectroscopy (μ-XRF) and micro-focus X-ray absorption fine spectroscopy (μ-XAFS). Then, the intracellular immigration and chemical transformation of PM2.5 components in human bronchial epithelial cells (BEAS-2B) after exposure to PM2.5 will be explored by scanning transmission X-ray microscopy (STXM) and near edge X-ray absorption fine structure (NEXAFS). Furthermore, PM2.5 induce oxidative stress in wild type, nrf2 overexpression (nrf2+/+) and nrf2 knock-out (nrf2-/-) BEAS-2B cells by electron spin resonance (ESR) and immunofluorescence technique. Simultaneously, we will investigate and evaluate that PM2.5 induces Nrf2-mediated defense mechanisms against oxidative damage and inflammation response in cells whether is associated with activation of Nrf2/ARE signaling pathway using single cell genomics. In summary, our results obtained from this study can characterized the pathological and physiological roles of PM2.5 in the respiratory disease.

针对PM2.5引发呼吸道损伤的病理生理学机理，本项目拟将同步辐射技术与细胞分子生物学方法相结合，研究PM2.5在呼吸道细胞内的迁移转化及其诱导细胞氧化损伤的分子作用机制。在微束X射线μ-XRF和μ-XAFS技术测定PM2.5单颗粒物的组成和化学种态的基础上，应用活细胞工作站、STXM和NEXAFS技术研究人呼吸道上皮BEAS-2B细胞对PM2.5的胞吞作用和迁移特征，分析PM2.5（含金属、氮、氧等）在细胞内的化学种态和结构，获得细胞内PM2.5的化学转化信息和原位成像；进一步采用顺磁共振和单细胞基因组学等技术，研究PM2.5的化学转化对野生型、nrf2+/+和nrf2-/- BEAS-2B细胞氧化应激和炎性反应的影响，阐明Nrf2/ARE信号通路及其相关基因表达在细胞氧化损伤的作用机制，筛选出敏感性调控分子，为PM2.5的呼吸道损伤病理生理学机理研究和干预策略提供依据。

针对PM2.5引发呼吸道损伤的病理生理学机理，本项目拟将同步辐射技术与细胞分子生物学方法相结合，研究PM2.5在呼吸道细胞内的迁移转化及其诱导细胞氧化损伤的分子作用机制。在微束X射线μ-XRF和μ-XAFS技术测定PM2.5单颗粒物的组成和化学种态的基础上，应用活细胞工作站、STXM和NEXAFS技术研究人呼吸道上皮BEAS-2B细胞对PM2.5的胞吞作用和迁移特征，分析PM2.5（含金属、氮、氧等）在细胞内的化学种态和结构，获得细胞内PM2.5的化学转化信息和原位成像；进一步采用顺磁共振和单细胞基因组学等技术，研究PM2.5的化学转化对野生型、nrf2+/+和nrf2-/- BEAS-2B细胞氧化应激和炎性反应的影响，阐明Nrf2/ARE信号通路及其相关基因表达在细胞氧化损伤的作用机制，并筛选出相关的调控分子，为PM2.5的呼吸道损伤病理生理学机理研究和干预策略提供依据。