Analysis of the activation routes induced by different metal oxide nanoparticles on human lung epithelial cells

Nanoparticles (Nps) can induce toxicity in the lung by accidental or intentional exposure. The main objective of the study reported here was to characterize the effect that four metal oxide Nps (CeO 2 , TiO 2 , Al 2 O 3 and ZnO) had at the cellular level on a human lung epithelial cell line. This goal was achieved by studying the capacity of the Nps to activate the main mitogen-activated protein kinases (MAPKs) and the nuclear factor NFκB. Only ZnO Nps were able to activate all of the MAPKs and the release of Zn 2+ ions was the main cause of activation. ZnO and Al 2 O 3 Nps activated the NFκB pathway and induced the release of inflammatory cytokines. CeO 2 and TiO 2 Nps were found to have safer profiles.The graphical abstract was obtained using Servier Medical Art.