Urban air particles from Buenos Aires activates NFKB, MUC5AC and IL-8 production in A549 cells.

ASTORT F., ORONA N., FERRARO S., COSTANTINO LE., MAGLIONE G., TASAT D.R

Congreso; SETAC Latin America 11th Biennial Meeting; 2015

SETAC LA

Airborne particular matter (PM) is one of the major air contaminants in megacities. Its physicochemical composition depends among others on the characteristic of the emission source being vehicular particle emission the main pollution source in Buenos Aires city. Exposure to PM in urban areas is associated with increased morbidity and mortality mainly due to cardiorespiratory diseases. Previously, we characterized Urban Air Particles from downtown Buenos Aires (UAP-BA), and evaluated its effect on the respiratory tract employing an in vivo animal model. We demonstrated that UAP-BA are ultrafine particles with no metallic traces able to generate lung inflammation and oxidative metabolism imbalance probably due to the high content of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) adsorbed to its carbon core. However, the cellular mechanism involved in UAP-BA toxic effect hasn´t been studied yet. The objective of this work was to analyze in vitro human lung epithelial cells A549 signal transduction pathway after UAP-BA exposure. UAP-BA was collected using a Mini Vol sampler (1.8 L/min). A549 cells were exposed to 5 µg/ml UAP-BA for 4h and the following parameters were evaluated: IL-8 levels by ELISA; apoptosis by Hoechst staining; reactive oxygen species (ROS) by DHR123; reduced glutathione (GSH) levels by DTNB; Transcription factors: Nuclear Factor κB (NFκB), Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and mucin MUC5AC by immunochemistry; Heme Oxygenase-1 (HO-1), NAD(P)H dehydrogenase, quinone 1(NQO1) and Nrf2 mRNA levels by real time PCR. Our results revealed that exposure to 5 µg/ml UAP-BA for 4h resulted in a slight rise in ROS production, a decrease in GSH levels and no differences neither in Nrf2 nor in the HO-1 and NQO1 mRNA levels target genes. On the other hand, UAP-BA exposure activated NFκB and increased inflammatory proteins MUC5AC and IL-8. We conclude that the mechanism of the adverse effect of UAP-BA in human epithelial cell A549 involves redox alterations, no changes in antioxidant genes and activation of pro-inflammatory NFκB which, in turn, could be responsible for the induction of inflammatory mediators like IL-8 and MUC5AC.