Epidermal growth factor receptor (EGFR)-MAPK-nuclear factor(NF)-κB-IL8: A possible mechanism of particulate matter(PM) 2.5-induced lung toxicity.

Airway inflammation plays a central role in the pathophysiology of diverse pulmonary diseases. In this study, we investigated whether exposure to particulate matter (PM) 2.5, a PM with an aerodynamic diameter of less than 2.5 µm, enhances inflammation-related toxicity in the human respiratory system through activation of the epidermal growth factor receptor (EGFR) signaling pathway. Through cytokine antibody array analysis of two extracts of PM [water (W-PM ) and organic (O-PM ) soluble extracts] exposed to A549 (human alveolar epithelial cell), we identified eight cytokines changed their expression with W-PM and three cytokines with O-PM . Among them, epidermal growth factor (EGF) was commonly up-regulated by W-PM and O-PM . Then, in both groups, we can identify the increase in EGF receptor protein levels. Likewise, increases in the phosphorylation of ERK1/2 MAP kinase and acetylation of nuclear factor(NF)-κB were detected. We also detected an increase in IL-8 that was related to inflammatory response. And using the erlotinib as an inhibitor of EGFR, we identified the erlotinib impaired the phosphorylation of EGFR, ERK1/2, acetylation of NF-κB proteins and decreased IL-8. Furthermore, at in vivo model, we were able to identify similar patterns. These results suggest that PM may contribute to an abnormality in the human respiratory system through EGFR, MAP kinase, NF-κB, and IL-8 induced toxicity signaling. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1628-1636, 2017.