title: Inflammatory and oxidative stress responses of an alveolar epithelial cell line to airborne zinc oxide nanoparticles at the air-liquid interface: a comparison with conventional, submerged cell-culture conditions.
abstract: The biological effects of inhalable nanoparticles have been widely studied in vitro with pulmonary cells cultured under submerged and air-liquid interface (ALI) conditions. Submerged exposures are experimentally simpler, but ALI exposures are physiologically more realistic and hence potentially biologically more meaningful. In this study, we investigated the cellular response of human alveolar epithelial-like cells (A549) to airborne agglomerates of zinc oxide (ZnO) nanoparticles at the ALI, compared it to the response under submerged culture conditions, and provided a quantitative comparison with the literature data on different types of particles and cells. For ZnO nanoparticle doses of 0.7 and 2.5 μ g ZnO/cm(2) (or 0.09 and 0.33 cm(2) ZnO/cm(2)), cell viability was not mitigated and no significant effects on the transcript levels of oxidative stress markers (HMOX1, SOD-2 and GCS) were observed. However, the transcript levels of proinflammatory markers (IL-8, IL-6, and GM-CSF) were induced to higher levels under ALI conditions. This is consistent with the literature data and it suggests that in vitro toxicity screening of nanoparticles with ALI cell culture systems may produce less false negative results than screening with submerged cell cultures. However, the database is currently too scarce to draw a definite conclusion on this issue.
authors.affiliation: Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, Ingolstaedter Landstrasse 1, 85758 Neuherberg, Germany. alenz@helmholtz-muenchen.de
authors.forename: Anke-Gabriele
authors.initials: AG
authors.lastname: Lenz
authors.forename: Erwin
authors.initials: E
authors.lastname: Karg
authors.forename: Ellen
authors.initials: E
authors.lastname: Brendel
authors.forename: Helga
authors.initials: H
authors.lastname: Hinze-Heyn
authors.forename: Konrad L
authors.initials: KL
authors.lastname: Maier
authors.forename: Oliver
authors.initials: O
authors.lastname: Eickelberg
authors.forename: Tobias
authors.initials: T
authors.lastname: Stoeger
authors.forename: Otmar
authors.initials: O
authors.lastname: Schmid
mesh_terms: D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D018836:Inflammation Mediators / Q000378:metabolism; D053758:Nanoparticles / Q000009:adverse effects*; D018384:Oxidative Stress / Q000187:drug effects*; D011650:Pulmonary Alveoli / Q000378:metabolism* / Q000473:pathology; D020545:Respiratory Mucosa / Q000378:metabolism* / Q000473:pathology; D015034:Zinc Oxide / Q000009:adverse effects* / Q000494:pharmacology
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D015034:Zinc Oxide