Project description:Atopic dermatitis is increasing worldwide, correlating with air pollutions. Various organic components of pollutants activate transcription factor AhR (aryl-hydrocarbon receptor). We have established AhR-CA mice, whose keratinocytes express constitutive-active AhR, and these mice developed atopic dermatitis-like frequent scratching and allergic inflammation. In this study we performed ChIP-seq analyses and identified keratinocyte-specific AhR target genes, including inflammatory cytokines Tslp and IL33, and neurotrophic factor Artemin. While AhR-CA mice exhibited epidermal hyperinnervation and alloknesis leading to hypersensitivity to pruritus, blockade of Artemin alleviated these phenotypes. AhR-CA mice showed scratching-induced barrier insufficiency and enhanced sensitization to epicutaneously-applied antigens, recapitulating human atopic dermatitis. Consistently, AhR activation and Artemin expression was detected in the epidermis of atopic dermatitis patients and keratinocytes exposed to air pollutants. Thus, AhR in keratinocytes senses the environmental stimuli and responds to them through moderating inflammation. We propose a mechanism in which air pollution induces atopic dermatitis through AhR activation.
Project description:Atopic dermatitis is increasing worldwide, correlating with air pollutions. Various organic components of pollutants activate transcription factor AhR (aryl-hydrocarbon receptor). We have established AhR-CA mice, whose keratinocytes express constitutive-active AhR, and these mice developed atopic dermatitis-like frequent scratching and allergic inflammation. In this study we performed ChIP-seq analyses and identified keratinocyte-specific AhR target genes, including inflammatory cytokines Tslp and IL33, and neurotrophic factor Artemin. While AhR-CA mice exhibited epidermal hyperinnervation and alloknesis leading to hypersensitivity to pruritus, blockade of Artemin alleviated these phenotypes. AhR-CA mice showed scratching-induced barrier insufficiency and enhanced sensitization to epicutaneously-applied antigens, recapitulating human atopic dermatitis. Consistently, AhR activation and Artemin expression was detected in the epidermis of atopic dermatitis patients and keratinocytes exposed to air pollutants. Thus, AhR in keratinocytes senses the environmental stimuli and responds to them through moderating inflammation. We propose a mechanism in which air pollution induces atopic dermatitis through AhR activation.
Project description:In this study we used genomic profiling to characterize differences in expression of genes related to epidermal growth/differentiation and inflammatory circuits in skin lesions of psoriasis and atopic dermatitis (AD), comparing expression values to normal skin. Skin biopsies were collected from 9 patients with chronic atopic dermatitis, 15 psoriasis patients, and 9 healthy volunteers. Keywords: Genetic-pathology
Project description:Low environmental humidity aggravates symptoms of inflammatory skin diseases, e.g. of Atopic Dermatitis (AD). Using mice that develop AD-like symptoms, we show that an increase in environmental humidity rapidly rescues their cutaneous inflammation and associated epidermal abnormalities. Quantitative proteomics analysis of epidermal lysates of mice kept at low or high humidity identified novel humidity-regulated proteins, including Clca2/Clca3a2, a protein with previously unknown function in the skin.
Project description:In this study we used genomic profiling to characterize differences in expression of genes related to epidermal growth/differentiation and inflammatory circuits in skin lesions of psoriasis and atopic dermatitis (AD), comparing expression values to normal skin. Skin biopsies were collected from 9 patients with chronic atopic dermatitis, 15 psoriasis patients, and 9 healthy volunteers. Keywords: Genetic-pathology Psoriasis and AD are common inflammatory skin diseases which share important features, including: 1) large infiltrates of T-cells and inflammatory dendritic cells in skin lesions, 2) immune activation with up-regulated expression of many cytokines, chemokines, and inflammatory molecules 3) marked epidermal hyperplasia in chronic diseased skin and 4) defective barrier function with increased transepidermal water loss (TEWL), which reflects underlying alterations in keratinocyte differentiation. Using genomic profiling we provide a comprehensive comparison of chronic psoriasis and AD skin lesions as compared with normal skin.
Project description:Analysis of cultured epidermal keratinocytes treated with interleukin-4 (IL-4) and interleukin-13 (IL-13). IL-4 and IL-13 are up-regulated in atopic dermatitis. Results provide insight into the role of IL-4 and IL-13 cytokines in the pathogenesis of atopic dermatitis. Analysis of epidermal keratinocytes transfected with dual oxidase 1 (DUOX1) siRNA knockdown before treatment with IL-4 and IL-13. DUOX1 is one of the NOX family members of NADPH oxidases whose primary function is ROS generation. Results provide insight into the role of the incraesed expression of DUOX1 in IL-4/IL-13-treated NHEK for IL4/IL13 signaling. IL-4 and IL-13 induced gene expression in human epidermal keratinocytes (NHEK) was measured at 48 hours. Gene expression in NHEK tranfected with 10 nM DUOX1 siRNA followed by treatment with 100 ng/ml IL-4 and 100 ng/ml IL-13 was measured at 48 hours. Three independent experiments were performed using different strains for each experiment.
Project description:Analysis of cultured epidermal keratinocytes treated with interleukin-4 (IL-4) and interleukin-13 (IL-13). IL-4 and IL-13 are up-regulated in atopic dermatitis. Results provide insight into the role of IL-4 and IL-13 cytokines in the pathogenesis of atopic dermatitis. Analysis of epidermal keratinocytes transfected with dual oxidase 1 (DUOX1) siRNA knockdown before treatment with IL-4 and IL-13. DUOX1 is one of the NOX family members of NADPH oxidases whose primary function is ROS generation. Results provide insight into the role of the incraesed expression of DUOX1 in IL-4/IL-13-treated NHEK for IL4/IL13 signaling.
Project description:Clinical overlaps between psoriasis and atopic dermatitis are sometimes undiscernible, and there is no consensus whether to treat the overlap phenotype as psoriasis or atopic dermatitis. We enrolled patients diagnosed with either psoriasis or atopic dermatitis, and clinically re-stratified them into classic psoriasis, classic atopic dermatitis, and the overlap phenotype between psoriasis and atopic dermatitis. We compared gene expression profiles of lesional and nonlesional skin biopsy tissues between the three comparison groups. Global mRNA expression and T-cell subset cytokine expression in the skin of the overlap phenotype were consistent with the profiles of psoriasis and different from the profiles of atopic dermatitis. Unsupervised k-means clustering indicated that the best number of distinct clusters for the total population of the three comparison groups was two, and the two clusters of psoriasis and atopic dermatitis were differentiated by gene expression. Our study suggests that clinical overlap phenotype between psoriasis and atopic dermatitis has dominant molecular features of psoriasis, and genomic biomarkers can differentiate psoriasis and atopic dermatitis at molecular levels in patients with a spectrum of psoriasis and atopic dermatitis.
Project description:Defects of filaggrin (FLG) compromise epidermal barrier function and represent an important known genetic risk factor for atopic dermatitis (AD), but also for systemic atopy, including allergic sensitization and asthma. A loss of epidermal barrier integrity can provide a significant stress for the cells in both the epidermis as well as the underlying dermal layer of the skin, either due to the increased moisture evaporation from the skin or increased penetration of the antigens and microflora into the lower layers. This analysis was therefore designed to understand the effect of this loss of barrier integrity on the total skin transcriptional profile.