Synergic effects of 9,10-phenanthrenequinone and cadmium on pro-inflammatory responses in airway epithelial cells

We investigated the synergic effects of components of particulate matter with aerodynamic diameters <= 2.5 mu m (PM2.5) on airway inflammation. Co-exposure to cadmium (Cd) and 9,10-phenanthrenequinone (9,10-PQ) additively/synergistically increased pro-inflammatory responses in airway epithelial cells, whereas co-exposure to Cd and phenanthrene resulted in no acceleration. These results suggest that the combination of metal and a quinone derivative can contribute to the exacerbation of respiratory diseases by PM2.5.