Project description:Lipids play a critical role in the skin as components of the epidermal barrier and as sig-naling molecules. Atopic dermatitis in dogs is associated with changes in the lipid composition of the skin, but whether these precede the onset of dermatitis or occur secondary to the dermatitis is unclear. We applied rapid lipid profiling mass spectrometry methods to skin and blood samples of dogs and determined changes following systemic treatment. Thirty control dogs and 30 atopic dogs with mild to moderate dermatitis were enrolled. Marked differences in lipid profiles were observed between control, nonlesional and lesional skin of dogs. Additionally, there were significant altera-tions in the lipid composition of the blood samples indicating systemic changes in lipid metabolism. Treatment with oclacitinib or lokivetmab resulted in a significant decrease of the disease clinical severity associated with changes in skin and blood lipids. A set of lipid features of the skin were selected as biomarkers that classified samples as control or atopic dermatitis with 95% accuracy, whereas blood lipids discriminated between control and atopic dogs with 82% accuracy. These data suggest that atopic dermatitis is a systemic disease and support the use of rapid lipid profiling to identify novel biomarkers.
Project description:Canine atopic dermatitis (AD) is clinically similar to human AD, implicating it as a useful model of human eosinophilic allergic disease. To identify cutaneous gene transcription changes in relatively early inflammation of canine AD, microarrays were used to monitor transcription in normal skin (n=13) and in acute lesional AD (ALAD) and nearby visibly nonlesional AD (NLAD) skin (n=13) from dogs. Scanning the putative abnormally-transcribed genes, several potentially relevant genes, some abnormally transcribed in both NLAD and ALAD (e.g. IL6, NFAM1, MSRA, and SYK), were observed. Comparison for abnormally-transcribed genes common to two related human diseases, human AD and asthmatic chronic rhinosinusitis with nasal polyps (aCRSwNP), further identified genes or gene sets likely relevant to eosinophilic allergic inflammation. These included 1) genes associated with alternatively-activated monocyte-derived cells, including members of the monocyte chemotactic protein (MCP) gene cluster, 2) members of the IL1 family gene cluster, 3) eosinophil-associated seven transmembrane receptor EMR1 and EMR3 genes, 4) interferon-inducible genes, and 5) keratin genes associated with hair and nail formation. Overall, numerous abnormally-transcribed genes were observed only in canine AD; however, many others are common to related human eosinophilic allergic diseases and represent therapeutic targets testable in dogs with AD. Total RNA from skin biopsy specimens from 13 Healthy (i.e. Normal) dogs were compared to total RNA from acute lesional skin biopsy specimens (i.e. ALAD) and nearby visibly nonlesional skin biopsy specimens (i.e. NLAD) from 13 dogs with atopic dermatitis.
Project description:Lipids play a critical role in the skin as components of the epidermal barrier and as sig-naling molecules. Atopic dermatitis in dogs is associated with changes in the lipid composition of the skin, but whether these precede the onset of dermatitis or occur secondary to the dermatitis is unclear. We applied rapid lipid profiling mass spectrometry methods to skin and blood samples of dogs and determined changes following systemic treatment. Thirty control dogs and 30 atopic dogs with mild to moderate dermatitis were enrolled. Marked differences in lipid profiles were observed between control, nonlesional and lesional skin of dogs. Additionally, there were significant altera-tions in the lipid composition of the blood samples indicating systemic changes in lipid metabolism. Treatment with oclacitinib or lokivetmab resulted in a significant decrease of the disease clinical severity associated with changes in skin and blood lipids. A set of lipid features of the skin were selected as biomarkers that classified samples as control or atopic dermatitis with 95% accuracy, whereas blood lipids discriminated between control and atopic dogs with 82% accuracy. These data suggest that atopic dermatitis is a systemic disease and support the use of rapid lipid profiling to identify novel biomarkers.
Project description:Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsies were collected from six sensitized and six non-sensitized Beagle dogs from normal, non-treated skin before and six and 24 hours after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data was compared between groups (unpaired design). After 24 hours 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentration in allergen treated skin of sensitized dogs compared to their saline-treated skin and compared to the control specimens. Functional annotation clustering, pathway-and co-citation analysis showed, that the genes with increased expression were involved in inflammation, wound healing and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. As the sensitized dogs did not show differences in the untreated skin compared to controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis. 60 canine (dog) skin tissue samples; six sensitized and six non-sensitized Beagle dogs; samples collected before (0h), 6h and 24h after challenge with allergen; samples collected from a skin area treated with saline and from an area treated with allergen
Project description:Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsies were collected from six sensitized and six non-sensitized Beagle dogs from normal, non-treated skin before and six and 24 hours after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data was compared between groups (unpaired design). After 24 hours 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentration in allergen treated skin of sensitized dogs compared to their saline-treated skin and compared to the control specimens. Functional annotation clustering, pathway-and co-citation analysis showed, that the genes with increased expression were involved in inflammation, wound healing and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. As the sensitized dogs did not show differences in the untreated skin compared to controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis.
Project description:We used Drop-seq and next generation sequencing to determine gene expression differences in dogs with atopic dermatitis and healthy dogs in peripheral blood mononuclear cells in an unbiased way. Using Seurat, we find 13 discrete immune cells clusters, including a cluster enriched for Gata3 expressing T cells with 95 differentially expressed genes between healthy and allergic dogs.
Project description:The aim of the study was to identify genes which are differentially expressed in the blood of dogs with canine atopic dermatitis (AD) in comparison to healthy control dogs. Diagnosis of AD was based on compatible history and clinical signs determined using Willemse and Prélaud diagnostic criteria, completed by Favrot criteria as follows: pruritus sine material, indoor lifestyle and the exclusion of other causes of pruritus ongoing for at least one year. Clinical diagnosis of atopic dermatitis was confirmed by serological allergy testing (IDEXX allergic panel test) and intradermal skin testing (Artuvetrin test set, Netherlands). In order to avoid the role of food antigens as a cause of the skin condition elimination diets was used for 6–8 weeks. No anti-inflammatory drugs were given for at least 3 weeks prior examination with serological test, intradermal test and blood collection. All dogs, which were classified to the investigated group had positive reactions in serological allergy testing and intradermal skin testing.
Project description:Canine atopic dermatitis (AD) is clinically similar to human AD, implicating it as a useful model of human eosinophilic allergic disease. To identify cutaneous gene transcription changes in relatively early inflammation of canine AD, microarrays were used to monitor transcription in normal skin (n=13) and in acute lesional AD (ALAD) and nearby visibly nonlesional AD (NLAD) skin (n=13) from dogs. Scanning the putative abnormally-transcribed genes, several potentially relevant genes, some abnormally transcribed in both NLAD and ALAD (e.g. IL6, NFAM1, MSRA, and SYK), were observed. Comparison for abnormally-transcribed genes common to two related human diseases, human AD and asthmatic chronic rhinosinusitis with nasal polyps (aCRSwNP), further identified genes or gene sets likely relevant to eosinophilic allergic inflammation. These included 1) genes associated with alternatively-activated monocyte-derived cells, including members of the monocyte chemotactic protein (MCP) gene cluster, 2) members of the IL1 family gene cluster, 3) eosinophil-associated seven transmembrane receptor EMR1 and EMR3 genes, 4) interferon-inducible genes, and 5) keratin genes associated with hair and nail formation. Overall, numerous abnormally-transcribed genes were observed only in canine AD; however, many others are common to related human eosinophilic allergic diseases and represent therapeutic targets testable in dogs with AD.