Comparison of cellular location and expression of Plakophilin-2 in epidermal cells from nonlesional atopic skin and healthy skin in German shepherd dogs.

Vet Dermatol
Authors
Abstract

BACKGROUND: Canine atopic dermatitis (CAD) is an inflammatory and pruritic allergic skin disease caused by interactions between genetic and environmental factors. Previously, a genome-wide significant risk locus on canine chromosome 27 for CAD was identified in German shepherd dogs (GSDs) and Plakophilin-2 (PKP2) was defined as the top candidate gene. PKP2 constitutes a crucial component of desmosomes and also is important in signalling, metabolic and transcriptional activities.

OBJECTIVES: The main objective was to evaluate the role of PKP2 in CAD by investigating PKP2 expression and desmosome structure in nonlesional skin from CAD-affected (carrying the top GWAS SNP risk allele) and healthy GSDs. We also aimed at defining the cell types in the skin that express PKP2 and its intracellular location.

ANIMALS/METHODS: Skin biopsies were collected from nine CAD-affected and five control GSDs. The biopsies were frozen for immunofluorescence and fixed for electron microscopy immunolabelling and morphology.

RESULTS: We observed the novel finding of PKP2 expression in dendritic cells and T cells in dog skin. Moreover, we detected that PKP2 was more evenly expressed within keratinocytes compared to its desmosomal binding-partner plakoglobin. PKP2 protein was located in the nucleus and on keratin filaments attached to desmosomes. No difference in PKP2 abundance between CAD cases and controls was observed.

CONCLUSION: Plakophilin-2 protein in dog skin is expressed in both epithelial and immune cells; based on its subcellular location its functional role is implicated in both nuclear and structural processes.

Year of Publication
2017
Journal
Vet Dermatol
Volume
28
Issue
4
Pages
377-e88
Date Published
2017 Aug
ISSN
1365-3164
DOI
10.1111/vde.12441
PubMed ID
28386956
PubMed Central ID
PMC5516137
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