Trichohyalin gene expression is negatively correlated with the severity of dermatitis in a canine atopic dermatitis model.

Introduction: Canine atopic dermatitis (AD) closely mimics human AD and is recognized as a beneficial animal model. House dust mites (HDM) are a common allergen for both species. The effects of chronic exposure to HDM on the skin have not been studied in this animal model, and it is not known how changes in gene expression correlate to the severity of dermatitis.

Studies Using Antibodies against Filaggrin and Filaggrin 2 in Canine Normal and Atopic Skin Biopsies.

Filaggrin is important for the skin barrier and atopic dermatitis. Another filaggrin-like protein, filaggrin 2, has been described. We evaluated antibodies against both filaggrins in normal and atopic skin biopsies from dogs before and after allergen challenges (D0, D1, D3 and D10).

Immunolocalization and Expression of JAK1 and JAK3 in the Skin of Dust Mite-Sensitive Beagle Dogs before and after Allergen Exposure.

Janus kinase (JAK) pathways have emerged as targets of treatment, yet localization and expression of JAK1 and JAK3 in canine atopic skin have not been studied. This study aimed to compare the localization and expression of JAK1 and JAK3 in the skin of atopic dogs before and after allergen exposure. Skin biopsies taken from atopic beagles sensitized to house dust mites (HDM) before (D0) and after four weeks (D28) of allergen exposure were stained.

Differences in Behavior between Normal and Atopic Keratinocytes in Culture: Pilot Studies.

Skin barrier dysfunction is important in atopic dermatitis and can be secondary to inflammation. Observation of keratinocytes in culture may show intrinsic differences. TransEpithelial Electrical Resistance (TEER) measures epithelial permeability.

Canine Epidermal Keratinocytes (CPEK) Grown in Monolayer Are Not Representative of Normal Canine Keratinocytes for Permeability Studies: Pilot Studies.

Canine progenitor epidermal keratinocytes (CPEK) are used as canine keratinocyte cell line. Their suitability for skin barrier studies is unknown. Measurement of transepithelial electric resistance (TEER) evaluates epithelial permeability.

Topical κ-opioid receptor agonist asimadoline improves dermatitis in a canine model of atopic dermatitis.

This prospective, 4-week, placebo-controlled, cross-over study aimed to investigate the efficacy of 1% topical κ-opioid agonist, asimadoline, in a model of canine atopic dermatitis (AD). Fourteen beagles were challenged with house dust mites every 3-4 days for a total of 9 challenges. Severity of dermatitis was assessed, and pruritus was monitored using GoPro HERO cameras.

Comparison of various treatment options for canine atopic dermatitis: a blinded, randomized, controlled study in a colony of research atopic beagle dogs.

Background: No study has directly compared the various treatment options for canine atopic dermatitis and their effects on skin barrier.

Hypothesis/objectives: To compare prednisone, oclacitinib, ciclosporin and lokivetmab treatment of atopic dermatitis.

Animals: Nineteen atopic beagle dogs.

Topical treatment with SPHINGOLIPIDS and GLYCOSAMINOGLYCANS for canine atopic dermatitis.

Background: Skin barrier dysfunction plays a key role in atopic dermatitis (AD). This impairment is related to altered composition and metabolism of epidermal sphingolipids and a deficiency of ceramides. Glycosaminoglycans (GAGs), and especially hyaluronic acid, could be useful in the management of AD.

A pilot study on the effect of oclacitinib on epicutaneous sensitization and transepidermal water loss in a colony of atopic beagle dogs.

Background: Dogs with atopic dermatitis are prone to sensitization to environmental allergens due to increased skin permeability; the effect of treatments on epicutaneous sensitizations is unknown.

Hypothesis/objectives: To evaluate if oclacitinib (i) prevents new sensitizations and (ii) affects skin barrier function.

Animals: Atopic beagle dogs.

Evaluation on the effects of 0.1% Peumus boldus leaf and Spiraea ulmaria plant extract combination on bacterial colonization in canine atopic dermatitis: A preliminary randomized, placebo controlled, double-blinded study.

Defective skin barrier characterize canine atopic dermatitis (AD). Pyoderma is the most common complication. Herbal compounds have been suggested as alternatives to control bacterial colonization for their effect on natural antimicrobial peptides (AMPs).

Single blinded, randomized, placebo-controlled study on the effects of ciclosporin on cutaneous barrier function and immunological response in atopic beagles.

Ciclosporin (CsA) is a common treatment for canine atopic dermatitis (cAD). cAD is a very common skin disease with a multifactorial pathogenesis due to complex interactions between the host and the environment. The purpose of this study was to describe the physical and immunological effects of CsA in cAD using a canine model of AD.

Investigation of the correlation of serum IL-31 with severity of dermatitis in an experimental model of canine atopic dermatitis using beagle dogs.

Background: IL-31 is a cytokine that is believed to play an important role in atopic dermatitis (AD). IL-31 levels positively correlate with disease severity in children with AD. Currently, there is no study that has investigated such a correlation in atopic dogs.

Randomized, double-blinded, placebo-controlled pilot study on the effects of topical blackcurrant emulsion enriched in essential fatty acids, ceramides and 18-beta glycyrrhetinic acid on clinical signs and skin barrier function in dogs with atopic dermatitis.

Background: Lipid-based emulsions can be useful for the management of canine atopic dermatitis (cAD). 18-beta glycyrrhetinic acid (GRA), a component of liquorice root, has anti-inflammatory and anti-pruritic effects.

Hypothesis/objectives: To evaluate the effects of a topical lipid emulsion containing ceramides, fatty acids and GRA on clinical signs of cAD and skin barrier in a randomized, double-blinded, placebo-controlled trial.

Evaluation of the in vitro effect of Boldo and Meadowsweet plant extracts on the expression of antimicrobial peptides and inflammatory markers in canine keratinocytes.

Dogs with allergies are prone to skin infections and treatments/preventatives to boost innate immune-defenses are beneficial. The aim of this study was to evaluate the effects of Boldo and Meadowsweet extracts on the expression of β-defensins (cBD), cathelicidin (cCath), and pro-inflammatory cytokines in canine keratinocyte. This study had two phases.

Decreased expression of caspase-14 in an experimental model of canine atopic dermatitis.

Alterations in skin barrier function and filaggrin expression have been reported in atopic dermatitis (AD). Caspase-14, a protease important for filaggrin processing, is decreased in human AD. Atopic Beagle dogs with skin barrier alterations have been validated as model for AD.

A comparative study of epidermal tight junction proteins in a dog model of atopic dermatitis.

Background: Tight junctions (TJ) are important for skin barrier function and could be relevant in modulating allergen penetration in atopic dermatitis (AD). Humans with AD have been described to have decreased expressions of some TJ proteins in the skin.

Hypothesis/objectives: This study aimed to investigate TJ protein expression using an experimental AD model in dogs.

First report in a dog model of atopic dermatitis: expression patterns of protease-activated receptor-2 and thymic stromal lymphopoietin.

Background: Protease-activated receptor (PAR)-2 plays a crucial role in inflammation and the skin barrier. Protease-activated receptor-2 is activated by proteolytic enzymes of allergens and stimulates thymic stromal lymphopoietin (TSLP), promoting T-helper 2 cytokines. In humans with atopic dermatitis (AD), increased expression of PAR-2 and TSLP has been reported.

Evaluation of antimicrobial peptides and cytokine production in primary keratinocyte cell culture from healthy and atopic beagles.

Increased secretion of antimicrobial peptides and cytokines is present in atopic skin. The purpose of this study was to compare the production of β-defensin (cBD)3-like, cathelicidin (cCath) and cytokines in atopic and healthy canine keratinocytes. Seven atopic house dust mites (HDMs) sensitive and five healthy age-matched beagles were used.

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

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.

Investigation of the effect of probiotic exposure on filaggrin expression in an experimental model of canine atopic dermatitis.

Background: Atopic dermatitis (AD) results from complex interactions between an impaired skin barrier and immunological stimulation. Filaggrin is a key protein for the skin barrier, and its expression is decreased in subsets of atopic dogs and can be modified by inflammation; thus, immunomodulatory approaches may alter its expression. Probiotics have been explored for the prevention and treatment of allergies, owing to their immunomodulatory properties; however, it is currently unknown whether they can modulate filaggrin expression.

Early exposure to probiotics in a canine model of atopic dermatitis has long-term clinical and immunological effects.

Probiotics modulate the immune response and may have protective effects against atopic dermatitis (AD). Clinical trials using dogs with spontaneous disease are limited by confounding factors such as different diets, environments and sensitizations while a more controlled evaluation is possible using experimental models. A validated model of canine AD showed that early exposure to Lactobacillus rhamnosus GG (LGG) significantly decreases allergen-specific IgE and partially prevents AD in the first 6 months of life.