The cytotoxicity of PM 2.5 and its effect on the secretome of normal human bronchial epithelial cells.

Exposure to airborne fine particulate matter (PM 2.5 ) induced various adverse health effects, such as metabolic syndrome, systemic inflammation, and respiratory disease. Many works have studied the effects of PM 2.5 exposure on cells through intracellular proteomics analyses. However, changes of the extracellular proteome under PM 2.5 exposure and its correlation with PM 2.5 -induced cytotoxicity still remain unclear. Herein, the cytotoxicity of PM 2.5 on normal human bronchial epithelia cells (BEAS-2B cells) was evaluated, and the secretome profile of BEAS-2B cells before and after PM 2.5 exposure was investigated. A total of 83 proteins (58 upregulated and 25 downregulated) were differentially expressed in extracellular space after PM 2.5 treatment. Notably, we found that PM 2.5 promoted the release of several pro-apoptotic factors and induced dysregulated secretion of extracellular matrix (ECM) constituents, showing that the abnormal extracellular environment attributed to PM 2.5 -induced cell damage. This study provided a secretome data for the deep understanding of the molecular mechanism underlying PM 2.5 -caused human bronchial epithelia cell damage.