Filaggrin in Canine Skin

Filaggrin is an epidermal protein that contributes to the structure of the cornified envelope. Impaired filaggrin functions, either by filaggrin gene (FLG) mutation or by altered filaggrin expression, may lead to skin disease and enhance antigen penetration. The discovery of the association between FLG mutations and human atopic dermatitis, together with the recent draft dog genome database, evoked filaggrin studies in canine tissue since dogs have a similar disease, canine atopic dermatitis (CAD). Although canine FLG mutations have not yet been identified and the FLG has been merged with the FLG2 in the latest draft dog genome (canFam3, September 2011), specific antibodies to canine filaggrin showed protein location in the epidermal layer. In CAD, filaggrin protein expression was generally decreased, although results at transcript levels varied. Further studies of the protein structure and function should be investigated.