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Hensel P, Saridomichelakis M, Eisenschenk M, Tamamoto-Mochizuki C, Pucheu-Haston C, Santoro D. Update on the role of genetic factors, environmental factors and allergens in canine atopic dermatitis. Vet Dermatol 2024; 35:15-24. [PMID: 37840229 DOI: 10.1111/vde.13210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 07/14/2023] [Accepted: 09/26/2023] [Indexed: 10/17/2023]
Abstract
BACKGROUND Canine atopic dermatitis (cAD) is a common, complex and multifactorial disease involving, among others, genetic predisposition, environmental factors and allergic sensitisation. OBJECTIVE This review summarises the current evidence on the role of genetic and environmental factors and allergic sensitisation in the pathogenesis of cAD since the last review by ICADA in 2015. MATERIALS AND METHODS Online citation databases and proceedings from international meetings on genetic factors, environmental factors and allergens relevant to cAD that had been published between 2015 and 2022 were reviewed. RESULTS Despite intensive research efforts, the detailed genetic background predisposing to cAD and the effect of a wide range of environmental factors still need more clarification. Genome-wide association studies and investigations on genetic biomarkers, such as microRNAs, have provided some new information. Environmental factors appear to play a major role. Lifestyle, especially during puppyhood, appears to have an important impact on the developing immune system. Factors such as growing up in a rural environment, large size of family, contact with other animals, and a nonprocessed meat-based diet may reduce the risk for subsequent development of cAD. It appears that Toxocara canis infection may have a protective effect against Dermatophagoides farinae-induced cAD. House dust mites (D. farinae and D. pteronyssinus) remain the most common allergen group to which atopic dogs react. Currently, the major allergens related to D. farinae in dogs include Der f 2, Der f 15, Der f 18 and Zen 1. CONCLUSIONS AND CLINICAL RELEVANCE Canine atopic dermatitis remains a complex, genetically heterogeneous disease that is influenced by multiple environmental factors. Further, well-designed studies are necessary to shed more light on the role of genetics, environmental factors and major allergens in the pathogenesis of cAD.
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Affiliation(s)
| | | | | | - Chie Tamamoto-Mochizuki
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Cherie Pucheu-Haston
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Domenico Santoro
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
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2
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Abstract
Human filaggrin (FLG) plays a key role in epidermal barrier function, and loss-of-function mutations of its gene are primarily responsible for the development of human atopic dermatitis (AD). FLG expression is also reduced in the epidermis of atopic patients, due to the transcriptional effect of Th2 type cytokines. Canine atopic dermatitis (CAD) is a prevalent skin disease that shares many clinical and pathogenic features with its human homologue. The aim of this review is discuss current knowledge on canine filaggrin (Flg) in both healthy and atopic dogs, as compared to the human protein. Although the molecular structures of the two proteins, as deduced from the sequences of their gene, are different, their sites of expression and their proteolytic processing in the normal epidermis are similar. Concerning the expression of Flg in CAD, conflicting results have been published at the mRNA level and little accurate information is available at the protein level. It derives from a large precursor, named profilaggrin (proFLG), formed by several FLG units and stored in keratohyalin granules of the stratum granulosum. Canine and human proFLG sequences display little amino acid similarity (33% as shown using the Basic Local Alignment Search Tool (BLAST)) except at the level of the S100 homologous part of the N-terminus (75%). Genetic studies in the dog are at an early stage and are limited by the variety of breeds and the small number of cases included. Many questions remain unanswered about the involvement of Flg in CAD pathogenesis.
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Affiliation(s)
- Daniel Combarros
- UDEAR, Université de Toulouse, INSERM UPS, Toulouse, France.,Université de Toulouse, ENVT, Toulouse, France
| | - Marie-Christine Cadiergues
- UDEAR, Université de Toulouse, INSERM UPS, Toulouse, France.,Université de Toulouse, ENVT, Toulouse, France
| | - Michel Simon
- UDEAR, Université de Toulouse, INSERM UPS, Toulouse, France
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3
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Nuttall TJ, Marsella R, Rosenbaum MR, Gonzales AJ, Fadok VA. Update on pathogenesis, diagnosis, and treatment of atopic dermatitis in dogs. J Am Vet Med Assoc 2020; 254:1291-1300. [PMID: 31067173 DOI: 10.2460/javma.254.11.1291] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Improved understanding of the pathogenesis of atopic dermatitis in dogs has led to more effective treatment plans, including skin barrier repair and new targeted treatments for management of allergy-associated itch and inflammation. The intent of this review article is to provide an update on the etiologic rationale behind current recommendations that emphasize a multimodal approach for the management of atopic dermatitis in dogs. Increasing knowledge of this complex disease process will help direct future treatment options.
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4
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Eisenschenk M. Phenotypes of Canine Atopic Dermatitis. CURRENT DERMATOLOGY REPORTS 2020. [DOI: 10.1007/s13671-020-00303-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Früh SP, Saikia M, Eule J, Mazulis CA, Miller JE, Cowulich JM, Oyesola OO, Webb LM, Peng SA, Cubitt RL, Danko CG, Miller WH, Tait Wojno ED. Elevated circulating Th2 but not group 2 innate lymphoid cell responses characterize canine atopic dermatitis. Vet Immunol Immunopathol 2020; 221:110015. [PMID: 32058160 DOI: 10.1016/j.vetimm.2020.110015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 12/11/2022]
Abstract
Atopic dermatitis (AD) is an allergic skin disease that causes significant morbidity and affects multiple species. AD is highly prevalent in companion dogs, and the clinical management of the disease remains challenging. An improved understanding of the immunologic and genetic pathways that lead to disease could inform the development of novel treatments. In allergic humans and mouse models of AD, the disease is associated with Th2 and group 2 innate lymphoid cell (ILC2) activation that drives type 2 inflammation. Type 2 inflammation also appears to be associated with AD in dogs, but gaps remain in our understanding of how key type 2-associated cell types such as canine Th2 cells and ILC2s contribute to the pathogenesis of canine AD. Here, we describe previously uncharacterized canine ILC2-like cells and Th2 cells ex vivo that produced type 2 cytokines and expressed the transcription factor Gata3. Increased circulating Th2 cells were associated with chronic canine AD. Single-cell RNA sequencing revealed a unique gene expression signature in T cells in dogs with AD. These findings underline the importance of pro-allergic Th2 cells in orchestrating AD and provide new methods and pathways that can inform the development of improved therapies.
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Affiliation(s)
- Simon P Früh
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Ithaca, NY 14853, USA
| | - Mridusmita Saikia
- Baker Institute for Animal Health and Department of Biomedical Sciences, Ithaca, NY 14853, USA
| | - Jeremy Eule
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Ithaca, NY 14853, USA
| | - Christina A Mazulis
- Section of Dermatology and Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Julia E Miller
- Section of Dermatology and Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Joby M Cowulich
- Section of Dermatology and Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Oyebola O Oyesola
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Ithaca, NY 14853, USA; Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Lauren M Webb
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Ithaca, NY 14853, USA; Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Seth A Peng
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Ithaca, NY 14853, USA
| | - Rebecca L Cubitt
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Ithaca, NY 14853, USA
| | - Charles G Danko
- Baker Institute for Animal Health and Department of Biomedical Sciences, Ithaca, NY 14853, USA
| | - William H Miller
- Section of Dermatology and Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Elia D Tait Wojno
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Ithaca, NY 14853, USA; Department of Immunology, University of Washington, Seattle, WA 98109, USA.
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Jensen-Jarolim E, Herrmann I, Panakova L, Janda J. Allergic and Atopic Eczema in Humans and Their Animals. Comp Med 2017. [DOI: 10.1007/978-3-319-47007-8_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Bizikova P, Pucheu-Haston CM, Eisenschenk MNC, Marsella R, Nuttall T, Santoro D. Review: Role of genetics and the environment in the pathogenesis of canine atopic dermatitis. Vet Dermatol 2015; 26:95-e26. [DOI: 10.1111/vde.12198] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2014] [Indexed: 01/16/2023]
Affiliation(s)
- Petra Bizikova
- Department of Clinical Sciences; College of Veterinary Medicine; North Carolina State University; 1060 William Moore Drive Raleigh NC 27606 USA
| | - Cherie M. Pucheu-Haston
- Department of Veterinary Clinical Sciences; School of Veterinary Medicine; Louisiana State University; 1909 Skip Bertman Drive Baton Rouge LA 70803 USA
| | | | - Rosanna Marsella
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; University of Florida; 2015 SW 16th Avenue Gainesville FL 32610 USA
| | - Tim Nuttall
- Royal (Dick) School of Veterinary Studies; Easter Bush Veterinary Centre; University of Edinburgh; Roslin EH25 9RG UK
| | - Domenico Santoro
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; University of Florida; 2015 SW 16th Avenue Gainesville FL 32610 USA
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Santoro D, Marsella R, Pucheu-Haston CM, Eisenschenk MNC, Nuttall T, Bizikova P. Review: Pathogenesis of canine atopic dermatitis: skin barrier and host-micro-organism interaction. Vet Dermatol 2015; 26:84-e25. [DOI: 10.1111/vde.12197] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2014] [Indexed: 01/19/2023]
Affiliation(s)
- Domenico Santoro
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; University of Florida; 2015 SW 16th Avenue Gainesville FL 32610 USA
| | - Rosanna Marsella
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; University of Florida; 2015 SW 16th Avenue Gainesville FL 32610 USA
| | - Cherie M. Pucheu-Haston
- Department of Veterinary Clinical Sciences; School of Veterinary Medicine; Louisiana State University; 1909 Skip Bertman Drive Baton Rouge LA 70803 USA
| | | | - Tim Nuttall
- Royal (Dick) School of Veterinary Studies; Easter Bush Veterinary Centre; University of Edinburgh; Roslin EH25 9RG UK
| | - Petra Bizikova
- Department of Clinical Sciences; College of Veterinary Medicine; North Carolina State University; 1060 William Moore Drive Raleigh NC 27606 USA
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Popa I, Portoukalian J, Haftek M. Specificity in the alteration of lesional and non-lesional skin lipids in atopic dogs. World J Dermatol 2015; 4:1-7. [DOI: 10.5314/wjd.v4.i1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 11/29/2014] [Accepted: 12/17/2014] [Indexed: 02/07/2023] Open
Abstract
The present paper is in the same time an overview of the literature concerning the alterations of lipids in the stratum corneum (SC) of atopic dogs and a review of data based on our publications. Knowing the importance of the SC barrier function for against pathogens in atopic dermatitis, we show for the first time a detailed biochemical analysis of lipids corresponding to the same amount of proteins in the successive layers of canine SC taken using tape stripping and their specificity as compared to humans. Also we show new results concerning the changes in the composition for protein-bound ceramides, and for the other lipids in involved and non-involved skin areas in atopic dogs. We show how a topical or oral treatment can restore the SC lipid composition and reconstruct the barrier integrity by up-regulating the biosynthesis of protein-bound ceramides.
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10
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Affiliation(s)
- Stephen Shaw
- UK VetDerm16 Talbot StreetWhitwickLeicestershireLE67 5AWUK
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11
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Nuttall T. The genomics revolution: will canine atopic dermatitis be predictable and preventable? Vet Dermatol 2013; 24:10-8.e3-4. [PMID: 23331674 DOI: 10.1111/j.1365-3164.2012.01094.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Heritability studies suggest that atopic dermatitis (AD) involves multiple genes and interactions with environmental factors. Advances in genomics have given us powerful techniques to study the genetics of AD. OBJECTIVE To review the application of these techniques to canine AD. RESULTS Candidate genes can be studied using quantitative PCR and genomic techniques, but these are hypothesis-dependent techniques and may miss novel genes. Hypothesis-free techniques avoid this limitation. Microarrays quantify expression of large numbers of genes, although false-positive associations are common. In the future, expression profiling could be used to produce a complete tissue transcriptome. Genome-wide linkage studies can detect AD-associated loci if enough affected dogs and unaffected relatives are recruited. Genome-wide association studies can be used to discover AD-associated single nucleotide polymorphisms without relying on related dogs. Genomic studies in dogs have implicated numerous genes in the pathogenesis of AD, including those involved in innate and adaptive immunity, inflammation, cell cycle, apoptosis, skin barrier formation and transcription regulation. These findings, however, have been inconsistent, and problems include low case numbers, inappropriate controls, inconsistent diagnosis, incomplete genome coverage, low-penetrance mutations and environmental factors. CONCLUSIONS Canine AD has a complex genotype that varies between breeds and gene pools. Breeding programmes to eliminate AD are therefore unlikely to succeed, but this complexity could explain variations in clinical phenotype and response to treatment. Genotyping of affected dogs will identify novel target molecules and enable better targeting of treatment and management options. However, we must avoid misuse of genomic data.
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Affiliation(s)
- Tim Nuttall
- The University of Liverpool School of Veterinary Science, Leahurst Campus, Neston, UK.
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12
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Abstract
BACKGROUND The stratum corneum (SC) is the outermost region of the epidermis and plays key roles in cutaneous barrier function in mammals. The SC is composed of 'bricks', represented by flattened, protein-enriched corneocytes, and 'mortar', represented by intercellular lipid-enriched layers. As a result of this 'bricks and mortar' structure, the SC can be considered as a 'rampart' that encloses water and solutes essential for physiological homeostasis and that protects mammals from physical, chemical and biological assaults. STRUCTURES AND FUNCTIONS The corneocyte cytoskeleton contains tight bundles of keratin intermediate filaments aggregated with filaggrin monomers, which are subsequently degraded into natural moisturizing compounds by various proteases, including caspase 14. A cornified cell envelope is formed on the inner surface of the corneocyte plasma membrane by transglutaminase-catalysed cross-linking of involucrin and loricrin. Ceramides form a lipid envelope by covalently binding to the cornified cell envelope, and extracellular lamellar lipids play an important role in permeability barrier function. Corneodesmosomes are the main adhesive structures in the SC and are degraded by certain serine proteases, such as kallikreins, during desquamation. CLINICAL RELEVANCE The roles of the different SC components, including the structural proteins in corneocytes, extracellular lipids and some proteins associated with lipid metabolism, have been investigated in genetically engineered mice and in naturally occurring hereditary skin diseases, such as ichthyosis, ichthyosis syndrome and atopic dermatitis in humans, cattle and dogs.
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Affiliation(s)
- Koji Nishifuji
- Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
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Santoro D, Marsella R, Ahrens K, Graves TK, Bunick D. Altered mRNA and protein expression of filaggrin in the skin of a canine animal model for atopic dermatitis. Vet Dermatol 2013; 24:329-36, e73. [DOI: 10.1111/vde.12031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/16/2013] [Indexed: 12/20/2022]
Affiliation(s)
- Domenico Santoro
- Department of Veterinary Clinical Medicine; University of Illinois at Urbana-Champaign; 1008 W Hazelwood Drive; Urbana; IL; 61802; USA
| | - Rosanna Marsella
- Department of Small Animal Clinical Sciences; University of Florida; 2015 SW 16th Avenue; Gainesville; FL 32615; USA
| | - Kim Ahrens
- Department of Small Animal Clinical Sciences; University of Florida; 2015 SW 16th Avenue; Gainesville; FL 32615; USA
| | - Thomas K. Graves
- Department of Veterinary Clinical Medicine; University of Illinois at Urbana-Champaign; 1008 W Hazelwood Drive; Urbana; IL; 61802; USA
| | - David Bunick
- Department of Veterinary Biosciences; University of Illinois at Urbana-Champaign; 2001 South Lincoln Avenue; Urbana; IL 60802; USA
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Marsella R. Does filaggrin expression correlate with severity of clinical signs in dogs with atopic dermatitis? Vet Dermatol 2013; 24:266-e59. [DOI: 10.1111/vde.12007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2012] [Indexed: 11/27/2022]
Affiliation(s)
- Rosanna Marsella
- Department of Small Animal Clinical Sciences; University of Florida; Gainesville; FL; USA
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Marsella R. Are transepidermal water loss and clinical signs correlated in canine atopic dermatitis? A compilation of studies. Vet Dermatol 2012; 23:238-e49. [DOI: 10.1111/j.1365-3164.2012.01055.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Roque JB, O'Leary CA, Kyaw-Tanner M, Duffy DL, Shipstone M. Real-time PCR quantification of the canine filaggrin orthologue in the skin of atopic and non-atopic dogs: a pilot study. BMC Res Notes 2011; 4:554. [PMID: 22188733 PMCID: PMC3339370 DOI: 10.1186/1756-0500-4-554] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 12/21/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Canine atopic dermatitis (AD) is a common inflammatory skin disease associated with defects in the epidermal barrier, particularly in West Highland white terriers (WHWTs). It shares many similarities with human AD, and so may be a useful animal model for this disease. Epidermal dysfunction in human AD can be caused by mutations in the gene encoding the epidermal protein filaggrin (FLG) and, in some atopic patients, be associated with altered FLG mRNA and protein expression in lesional and/or non-lesional skin. In experimental models of canine AD, mRNA expression of the orthologous canine filaggrin gene may be reduced in non-lesional skin compared with healthy controls. However, there is no published data on canine filaggrin mRNA expression in the skin of dogs with naturally-occurring AD. Hence, the aim of this pilot study was to develop a reverse transcriptase real-time PCR assay to compare filaggrin mRNA expression in the skin of atopic (n = 7) and non-atopic dogs (n = 5) from five breeds, including eight WHWTs. FINDINGS Overall, filaggrin mRNA expression in non-lesional atopic skin was decreased compared to non-lesional non-atopic skin (two fold change); however this difference was only statistically significant in the subgroup of WHWTs (P = 0.03). CONCLUSIONS Although limited by the small sample size, these results indicate that, comparable to some cases of human AD, altered filaggrin mRNA expression may exist in the skin of some atopic dogs with naturally-occurring disease. Additional studies, including larger sample numbers, will be necessary to confirm this finding and to investigate whether mutations in the filaggrin gene exist and contribute to epidermal lesions of AD in dogs.
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Affiliation(s)
- Joana Barros Roque
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
| | - Caroline A O'Leary
- Centre for Companion Animal Health, School of Veterinary Science, The University of Queensland, St Lucia, Queensland 4069, Australia
| | - Myat Kyaw-Tanner
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
| | - David L Duffy
- Genetic Epidemiology Laboratory, Queensland Institute of Medical Research, Herston, Queensland 4029, Australia
| | - Michael Shipstone
- Dermatology for Animals, Stafford Heights, Queensland 4053, Australia
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Is the skin barrier abnormal in dogs with atopic dermatitis? Vet Immunol Immunopathol 2011; 144:11-6. [DOI: 10.1016/j.vetimm.2011.07.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 07/15/2011] [Accepted: 07/18/2011] [Indexed: 12/12/2022]
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Roque JB, O’Leary CA, Duffy DL, Kyaw-Tanner M, Gharahkhani P, Vogelnest L, Mason K, Shipstone M, Latter M. Atopic dermatitis in West Highland white terriers is associated with a 1.3-Mb region on CFA 17. Immunogenetics 2011; 64:209-17. [DOI: 10.1007/s00251-011-0577-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 09/21/2011] [Indexed: 01/18/2023]
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Analysis of epidermal lipids in normal and atopic dogs, before and after administration of an oral omega-6/omega-3 fatty acid feed supplement. A pilot study. Vet Res Commun 2011; 35:501-9. [PMID: 21786009 DOI: 10.1007/s11259-011-9493-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2011] [Indexed: 01/28/2023]
Abstract
Alterations of the lipid expression in the skin of human and canine atopic subjects may be one of the key factors in the disease development. We have analyzed the ultrastructure of the clinically uninvolved skin of atopic dogs and compared it with the lipid composition of their tape-stripped stratum corneum (SC). The effect of a 2 month treatment of atopic dogs by food supplementation with a mixture of essential fatty acids was evaluated on skin samples taken before and after the treatment period. Electron microscopy revealed that the non-lesional skin of atopic dogs exhibited an abnormal and largely incomplete structure of the lamellar lipids with little cohesion between the corneocyte strata. The SC of atopic dogs was characterized by a significant decrease in the lipid content when compared to the healthy controls. Following oral supplementation with the mixture of essential fatty acids, the overall lipid content of the SC markedly increased. This feature was observed both with the free and, most importantly, with the protein-bound lipids (cholesterol, fatty acids and ceramides), the latter constituting the corneocyte-bound scaffold for ordinate organisation of the extracellular lipid bi-layers. Indeed, the semi-quantitative electron microscopy study revealed that the treatment resulted in a significantly improved organization of the lamellar lipids in the lower SC, comparable to that of the healthy dogs. Our results indicate the potential interest of long-term alimentary supplementation with omega-6 and omega-3 essential fatty acids in canine atopic dermatitis.
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Salzmann CA, Olivry TJM, Nielsen DM, Paps JS, Harris TL, Olby NJ. Genome-wide linkage study of atopic dermatitis in West Highland White Terriers. BMC Genet 2011; 12:37. [PMID: 21510878 PMCID: PMC3111396 DOI: 10.1186/1471-2156-12-37] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Accepted: 04/21/2011] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Canine atopic dermatitis (AD) is a common, heritable, chronic allergic skin condition prevalent in the West Highland White Terrier (WHWT). In canine AD, environmental allergens trigger an inflammatory response causing visible skin lesions and chronic pruritus that can lead to secondary bacterial and yeast infections. The disorder shares many of the clinical and histopathological characteristics of human AD and represents an animal model of this disorder that could be used to further elucidate genetic causes of human AD. Microsatellite markers genotyped in families of WHWTs affected with AD were used to perform a genome-wide linkage study in order to isolate chromosomal regions associated with the disorder. RESULTS Blood samples and health questionnaires were collected from 108 WHWTs spanning three families. A linkage simulation using these 108 dogs showed high power to detect a highly penetrant mutation. Ninety WHWTs were genotyped using markers from the Minimal Screening Set 2 (MSS-2). Two hundred and fifty six markers were informative and were used for linkage analysis. Using a LOD score of 2.7 as a significance threshold, no chromosomal regions were identified with significant linkage to AD. LOD scores greater than 1.0 were located in a 56 cM region of chromosome 7. CONCLUSIONS The study was unable to detect any chromosomal regions significantly linked to canine AD. This could be a result of factors such as environmental modification of phenotype, incorrect assignment of phenotype, a mutation of low penetrance, or incomplete genome coverage. A genome-wide SNP association study in a larger cohort of WHWTs may prove more successful by providing higher density coverage and higher statistical power.
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Affiliation(s)
- Cary A Salzmann
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
| | - Thierry JM Olivry
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
- Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, NC 27606, USA
| | - Dahlia M Nielsen
- Department of Genetics, North Carolina State University, Raleigh, NC 27606, USA
| | - Judith S Paps
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
| | - Tonya L Harris
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
| | - Natasha J Olby
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
- Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, NC 27606, USA
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21
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Marsella R, Olivry T, Carlotti DN. Current evidence of skin barrier dysfunction in human and canine atopic dermatitis. Vet Dermatol 2011; 22:239-48. [DOI: 10.1111/j.1365-3164.2011.00967.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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22
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