Introduction

Filaggrin and corneodesmosin are key proteins for the epidermal barrier function, but they remain poorly characterized in dogs.

Objective

To reveal the expression pattern of corneodesmosin and filaggrin in dog epidermis using antibodies raised to human proteins.

Methods

Thirty different murine monoclonal antibodies specific to either human filaggrin or corneodesmosin were assayed on skin biopsies and epidermal protein extracts of 10 normal dogs using immunocytochemistry and western blotting.

Results

Immunoelectron microscopy revealed anti-filaggrin labeling in keratohyaline granules (stratum granulosum, SG) and in the intracellular matrix of the lower stratum corneum (SC) (Figure 1). Anti-corneodesmosin antibody localized to the lamellar granules in SG and to the corneodesmosomes in SC (Figure 1, inset). This expression pattern of both proteins was identical with that observed in human skin. On immunoblot, the anti-corneodesmosin antibody reacted with corneodesmosin (52 kDa) and its proteolytic fragments of 49, 40, 36.5 and 33.5 kDa. Canine filaggrin appeared to be a 55 to 60 kDa protein.

Conclusion

Filaggrin and corneodesmosin are the specific targets of chosen monoclonal antibodies in the epidermis of dogs. These antibodies are useful tools for studies on various skin diseases in dogs and, in particular, of the epidermal barrier in canine atopic dermatitis.

VIN editor: Figures were not available at time of publication.