Copper in airborne fine particulate matter (PM 2.5 ) from urban sites causes the upregulation of pro-inflammatory cytokine IL-8 in human lung epithelial A549 cells.

Fine atmospheric particles, such as PM _2.5 , are strongly related to the onset and exacerbation of inflammatory responses leading to the development of respiratory and cardiovascular diseases. PM _2.5 is a complex mixture of tiny particles with different properties (i.e., size, morphology, and chemical components). Moreover, the mechanism by which PM _2.5 induces inflammatory responses has not been fully elucidated. Therefore, it is necessary to determine the composition of PM _2.5 to identify the main factors causing PM _2.5 -associated inflammation and diseases. In the present study, we investigated PM _2.5 from two sites (Fukue, a remote monitoring site, and Kawasaki, an urban monitoring site) with greatly different environments and PM _2.5 compositions. The results of ICP-MS and EDX-SEM indicated that PM _2.5 from Kawasaki contained more metals and significantly induced the expression of the pro-inflammatory cytokine gene IL-8 compared to the PM _2.5 from Fukue. We also verified the increased secretion of IL-8 protein from exposure to PM _2.5 from Kawasaki. We further investigated their effects on inflammatory response and cytotoxicity using metal nanoparticles (Cu, Zn, and Ni) and ions and found that the Cu nanoparticles caused a dose-dependent increase in IL-8 expression together with significant cell death. We also found that Cu nanoparticles enhanced the secretion of IL-8 protein. These results suggest that Cu in PM _2.5 is involved in lung inflammation.
(© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)