Project description:Barrier integrity is central to the maintenance of a healthy immunological homeostasis. Impaired skin barrier function is linked with enhanced allergen sensitization and the development of diseases such as atopic dermatitis (AD), which can precede the development of other allergic diseases such as food allergies and asthma. Epidemiological evidence indicates that children suffering from allergies have lower levels of dietary fibre-derived short-chain fatty acids (SCFA). Using an experimental model of AD, we report that a fermentable fibre-rich diet alleviates AD severity and systemic allergen sensitization. The gut-skin axis underpins this phenomenon through SCFA, which strengthen skin barrier integrity by altering mitochondrial metabolism of epidermal keratinocytes. SCFA promote keratinocyte differentiation and the production of key structural lipids, resulting in enhanced barrier function. Our results demonstrate that dietary fibre and SCFA mitigate AD by improving barrier integrity, ultimately limiting early systemic allergen sensitization and development of disease.
Project description:The prevalence of atopic diseases has increased with atopic dermatitis (AD) as the earliest manifestation. We assessed if molecular risk factors in atopic mothers influence their offsprings’ susceptibility to an atopic disease. Pairs of pregnant women and their infants with or without parental atopy were followed over the first 2 years of life. Global DNA methylation and differentially methylated regions (DMR) were determined in atopic and non-atopic mothers. During the first 2 years of life, AD was more prevalent in children of atopic compared to non-atopic mothers with an increase in food sensitization in children with AD. 165 DMRs distinguished atopic from non-atopic mothers. Maternal atopy combined with DMRs increased the offsprings’ predicted risk to develop AD from an odds ratio of 2.56 to 4.26.
Project description:The patho-mechanism of atopic dermatitis showing systemic involvement may be explained by Th17-related cytokines induced by FABP5 through systemic sensitization to a major allergen of a house dust mite.
Project description:The patho-mechanism of atopic dermatitis showing systemic involvement may be explained by Th17-related cytokines induced by FABP5 through systemic sensitization to a major allergen of a house dust mite.
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: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:Atopic dermatitis (AD) is the chronic inflammatory skin disease accompanied with severe pruritus. To explore the roles of EGR1 in atopic dermatitis and the relationship between EGR1 and pruritus-scratching behavior, we used a atopic dermatitis-like mouse model driven by house dust mite (HDM) treatment in wild type and EGR1 KO mice, followed with RNA-sequencing analysis.
Project description:D-galactose orally intake ameliorate DNCB-induced atopic dermatitis by modulating microbiota composition and quorum sensing. The increased abundance of bacteroidetes and decreased abundance of firmicutes was confirmed. By D-galactose treatment, Bacteroides population was increased and prevotella, ruminococcus was decreased which is related to atopic dermatitis.