Defense and repair mechanisms in the airway epithelium exposed to oxidative stress: effects of analogues of retinoic acid.
A model of rabbit tracheal epithelial (RTE) cells in vitro was developed in order to investigate the effects, on the airway epithelium, of reactive oxygen species (ROS) generated by H2O2 in association or not in association with Fe2+. The immediate consequence of a 24 h exposure of RTE cells to an oxidative stress was an increase in catalase activity whereas superoxide dismutase activity was not modified. A latter consequence of a chronic ROS insult was the induction of a repair mechanism which led to squamous metaplasia (SM). SM is characterized by a stratification of the epithelium, the expression of the cytokeratin 13 and the appearance of cells with cross-linked envelopes. Reversible modifications between mucociliary and squamous phenotype are modulated by retinoids. The action of retinoids is selective: metaplasia is inhibited by agonists of RAR alpha and beta receptors and not by an agonist of RAR gamma receptors.
Baeza-Squiban
A
A
Laboratoire de Cytophysiologie et Toxicologie cellulaire, Université Paris 7, France. Marano@paris7.jussieu.fr
Boisvieux-Ulrich
E
E
Delcher
L
L
Marano
F
F
D000818:Animals; D002374:Catalase / Q000378:metabolism; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000633:toxicity; D008024:Ligands; D008679:Metaplasia; D018384:Oxidative Stress / Q000502:physiology*; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000145:classification / Q000378:metabolism; D012176:Retinoids / Q000378:metabolism / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D013482:Superoxide Dismutase / Q000378:metabolism; D014132:Trachea / Q000187:drug effects / Q000473:pathology / Q000502:physiology*
D008024:Ligands; D017382:Reactive Oxygen Species; D018168:Receptors, Retinoic Acid; D012176:Retinoids; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase