Altered mRNA and protein expression of filaggrin in the skin of a canine animal model for atopic dermatitis

• Published in: Veterinary dermatology 2013-06, Vol.24 (3), p.329-e73
• Main Authors: Santoro, Domenico, Marsella, Rosanna, Ahrens, Kim, Graves, Thomas K., Bunick, David
• Format: Article
• Language: English
• Subjects: Animals; Case-Control Studies; Dermatitis, Atopic - metabolism; Dermatitis, Atopic - veterinary; Dog Diseases - metabolism; Dogs; Female; Intermediate Filament Proteins - genetics; Intermediate Filament Proteins - metabolism; Male; Real-Time Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Skin - metabolism
• ISSN: 0959-4493; 1365-3164
• DOI: 10.1111/vde.12031

Background Filaggrin is a structural protein that has attracted increasing interest over the past decade for its role in the pathogenesis of human atopic dermatitis (AD). Null mutations in its sequence are considered risk factors in the development of AD. Hypothesis/Objectives To investigate canine filaggrin mRNA and protein expression in the skin of atopic beagles with experimentally induced AD compared with breed‐matched healthy control dogs. Methods All dogs were environmentally challenged for 3 days consecutively with allergens to which the atopic dogs had been sensitized. Skin biopsy specimens were taken from six healthy and seven atopic beagles before and after allergen challenge. Canine filaggrin mRNA was measured using quantitative real‐time PCR. Indirect immunofluorescence was used to localize the filaggrin protein in canine skin. Analysis of variance with Tukey's multiple comparison test (over‐time effect) and unpaired Student's t‐test (treatment effect) were used. Values of P ≤ 0.05 were considered significant. Results Analysis of variance showed a significantly higher expression of filaggrin mRNA in atopic dogs compared with healthy control dogs (P = 0.004 on day 3 and P = 0.01 on day 10) and a decreased mRNA expression on day 3 in healthy control dogs (effect of time, P = 0.006). On blinded evaluation, filaggrin immunofluorescence was distributed homogeneously in the stratum granulosum and the stratum corneum in healthy dogs. Atopic dogs showed a patchy immunofluorescence pattern, which was exacerbated after environmental challenge. Conclusions and clinical importance Altered epidermal filaggrin mRNA expression and protein distribution was detected in this experimental model. Résumé Contexte La filaggrine est une protéine de structure qui a présenté un intérêt croissant au cours de la dernière décennie pour son rôle dans la pathogénie de la dermatite atopique humaine (AD). Les mutations nulles dans sa séquence sont considérées comme des facteurs de risque du développement de l'AD. Hypothèses/Objectifs Etudier l'ARNm de la filaggrine canine et l'expression protéique dans la peau de beagles atopiques avec AD expérimentalement induite comparée avec des chiens croisés sains contrôles. Méthodes Tous les chiens ont été testés pendant 3 jours consécutifs avec des allergènes auxquels les chiens atopiques étaient sensibilisés. Des biopsies cutanées ont été prélevées sur six chiens sains et sept beagles atopiques avant et après la provocation allergéniq