Role of size and composition of traffic and agricultural aerosols in the molecular responses triggered in airway epithelial cells

Abstract

The increased levels of fine particles in the atmosphere are suspected of aggravating cardiopulmonary diseases, but the determinants of particle toxicity are poorly understood. This work aims at studying the role of composition and size in the toxicity of size-segregated particulate matter (PM) collected at different sites on human bronchial epithelial cells. PM were sampled at a traffic urban site (Urb S) and a rural site (Rur S) during the pesticide-spreading period. Ultrafine (UF), fine (F), and coarse (C) PM were characterized by their shape and chemical composition. Whatever the site, the finest PM (UF and F) induced the mRNA expression of CYP1A1, a biomarker of polyaromatic hydrocarbons (PAH) exposure, NQO-1 and heme HO-1, two antioxidant responsive element-driven genes; and two effect biomarkers, GM-CSF, a proinflammatory cytokine and amphiregulin (AR), a growth factor. C PM have a low or no effect. Interestingly, AR is more strongly induced by rural PM at the same mass exposure. These discrepancies suggest involvement of PM chemical composition: rural PM bearing the characteristics of aged aerosols with a high content of water-soluble components, and PM at urban kerbside sites containing mainly water-insoluble components. To conclude, we provide evidence that the finest PM fractions, whatever their origin, are more prone to induce exposure and effect biomarkers. The AR differential expression suggests a source-dependent effect requiring further investigation because of the role of this growth factor in airway remodeling, a characteristic feature of chronic lung respiratory diseases exacerbated by particulate pollution.

Keywords::

• Pesticide
• oxidative stress
• xenobiotic metabolism
• cytokine
• amphiregulin

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Corrigendum

Acknowledgments

The authors thank the French ANR (Agence Nationale pour la Recherche), Legs Poix, and the Caisse d’Assurance Maladie des Professions Libérales de Province (Paris, France). The authors thank the Jacques Monod Institute (IJM, Paris, France) for the use of Genomic Platform and Geneviève Petit and Sandrine Carrat (LEPI) for MET analysis.

Declaration of interest

This work was supported by the grants from AFSSET (now ANSES) for the project PUFFIN2 (EST-2007-65). The PhD of Val Stéphanie is supported by ANSES and ADEME. The authors report no conflict of interest.