title: Exposure to dibenzofuran triggers autophagy in lung cells.
abstract: Environmental pollutants, such as dioxins and furans, are extremely toxic and related with pulmonary disease development. Exposure of A549 human lung cells to dibenzofuran showed both time- and concentration-dependent decreases in cell proliferation and MTT reduction, but no alterations in cell viability. No differences were observed in the number of apoptotic nuclei, which can be due to the energetic failure caused by dibenzofuran-induced ATP depletion. Moreover, cells in culture exposed to the pollutant showed an increase in the conversion of LC3, a protein involved in the autophagic process. Incubation of A549 lung cells with dibenzofuran caused an increase in Lysotracker Red staining, indicating an increase in lysosomal vacuoles content. These results suggest that exposure to dibenzofuran affects lung mitochondrial phosphorylative function, causing an increase in the population of dysfunctional mitochondria and an impairment in the energetic status maintenance, therefore stimulating autophagy as a possible rescue mechanism in this cell line.
authors.affiliation: CNC - Center for Neurosciences and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal.
authors.forename: Filipe V
authors.initials: FV
authors.lastname: Duarte
authors.forename: João S
authors.initials: JS
authors.lastname: Teodoro
authors.forename: Anabela P
authors.initials: AP
authors.lastname: Rolo
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Palmeira
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D001572:Benzofurans / Q000633:toxicity*; D015153:Blotting, Western; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004396:Coloring Agents; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism; D004785:Environmental Pollutants / Q000633:toxicity*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008168:Lung / Q000166:cytology* / Q000187:drug effects; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D017382:Reactive Oxygen Species / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000227:Adenine Nucleotides; D001572:Benzofurans; D004396:Coloring Agents; D004785:Environmental Pollutants; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D000255:Adenosine Triphosphate; C023614:dibenzofuran; D007770:L-Lactate Dehydrogenase; C022616:thiazolyl blue