Project description:To obtain a separation of the epidermal and dermal compartments in order to examine compartment specific biological mechanisms in the skin we incubated 4 mm human skin punch biopsies in ammonium thiocyanate (NH4SCN). We wanted to test 1) the histological quality of the dermo-epidermal separation obtained by different incubation times 2) the amount and quality of extractable epidermal RNA, and 3) its impact on sample RNA expression profiles assessed by large-scale gene expression microarray analysis in both normal and inflamed skin. At 30 minutes incubation, the split between dermis and epidermis was not always histologically well-defined (i.e. occurred partly intra-epidermally) but varied between subjects. Consequently, curettage along the dermal surface of the biopsy was added to the procedure. This modified method resulted in an almost perfect separation of the epidermal and dermal compartments and satisfactory amounts of high-quality RNA were obtained. Hybridization to Affymetrix HG_U133A 2.0 GeneChips showed that ammonium thiocyanate incubation had a minute effect on gene expression resulting in only one significantly downregulated gene (cystatin E/M). We conclude that epidermis can be reproducibly and almost completely separated from the dermis of 4 mm skin biopsies by 30 min incubation in 3.8% ammonium thiocyanate combined with curettage of the dermal surface, producing high-quality RNA suitable for transcriptional analysis. Our refined method of dermo-epidermal separation will undoubtedly prove valuable in the many different settings, where the epidermal and dermal compartments need to be evaluated separately. Upper buttock skin in 4 healthy subjects was exposed to sodium lauryl sulphate, or sampled directly. For each subject, 4 biopsies were obtained: Two from inflamed skin, and two from adjacent normal skin. One irritated and one normal skin sample was placed directly in RNAlater. The remaining two samples were incubated in ammonium thiocyanate for 30 minutes at RT and then placed in RNAlater without performing any separation of the dermal and epidermal layers. This was done to investigate the effect of 30 minutes treatment with ammonium thiocyanate on both inflamed and non-inflamed skin. Data was normalized with quantile method (matrix 1) Forearm biopsies from 13 volunteers were separated to epidermis and dermis by use of ammonium thiocyanate. For comparison of full skin and epidermis without irritation, data from identical probe sets from HG_U133A 2.0 and HG_U133 plus 2.0 was extracted and normalised as one data set using quantile method (matrix 2).
Project description:Skin constitutes the outer permeability barrier that protects the body from dehydration and a myriad of external assaults. Epidermal keratinocytes act as the first line of innate immune defense, and barrier defects underlie common inflammatory skin diseases. However, the molecular mechanisms that maintain barrier integrity when skin is under challenge to regulate the interplay between epidermal and immune cells are not fully understood. Here we report upregulated expression of transcriptional repressorencoding Ovol1 in epidermal cells of inflamed skin, and its functional importance in maintaining barrier integrity of physically or chemically challenged skin. Following stimulation with imiquimod, Ovol1-deficient mice exhibit significantly aggravated epidermal hyperplasia and psoriasis-like skin inflammation featuring persistent neutrophil accumulation. Using bulk and single-cell RNA-sequencing, we characterize molecular changes in epidermal, fibroblasts, and immune cells that reflect altered epidermal proliferation and differentiation and/or significantly enhanced inflammatory responses as consequences of Ovol1 deletion. We identify both proliferation/differentiation-regulating and neutrophil-attracting chemokine genes as candidate direct targets of Ovol1. Finally, we provide evidence for altered IL-1a signaling in the microenvironment of Ovol1- deficient inflamed skin that functionally contributes to neutrophil accumulation and epidermal hyperplasia. Collectively, our study demonstrates a protective role for an epidermally expressed, disease-linked transcription factor in coordinating robust barrier maintenance with suppression of skin inflammation.
Project description:We report the transcriptome analysis of epidermal CD8 tissue resident memory T (TRM) cells from healthy human skin. Specifically, epidermal CD8+CD103+CD49a+ and CD8+CD103+CD49- TRM cells from healthy human skin were sorted by FACS. Differential gene expression analysis revealed functional dichotomy of epidermal CD8+CD103+CD49a+ and CD8+CD103+CD49- TRM cells.
Project description:Epidermal homeostasis is governed by a balance between keratinocyte proliferation and differentiation with contributions from cell-cell interactions, but conserved or divergent mechanisms governing this equilibrium across species, and how an imbalance contributes to skin disease, are largely undefined. To address these questions, human skin single-cell RNA-sequencing (scRNA-seq) and spatial transcriptomics (ST) data were integrated and compared to mouse skin data. Human skin cell type annotation was improved by using matched ST data, highlighting the importance of spatial context in cell type identity, and ST refined cellular communication inference. In cross-species analyses, we identified a human spinous keratinocyte subpopulation that exhibited proliferative capacity and a heavy-metal processing signature, which was absent in mouse and may account for species differences in epidermal thickness. This human subpopulation was expanded in psoriasis and zinc-deficiency dermatitis, attesting to disease relevance and suggesting a paradigm of subpopulation dysfunction as a hallmark of disease. To assess additional potential subpopulation drivers of skin diseases, we performed cell-of-origin enrichment analysis within genodermatoses, nominating pathogenic cell subpopulations and their communication pathways, which highlighted multiple potential therapeutic targets. This integrated dataset is encompassed in a publicly available web resource to aid mechanistic and translational studies of normal and diseased skin.
Project description:To obtain a separation of the epidermal and dermal compartments in order to examine compartment specific biological mechanisms in the skin we incubated 4 mm human skin punch biopsies in ammonium thiocyanate (NH4SCN). We wanted to test 1) the histological quality of the dermo-epidermal separation obtained by different incubation times 2) the amount and quality of extractable epidermal RNA, and 3) its impact on sample RNA expression profiles assessed by large-scale gene expression microarray analysis in both normal and inflamed skin. At 30 minutes incubation, the split between dermis and epidermis was not always histologically well-defined (i.e. occurred partly intra-epidermally) but varied between subjects. Consequently, curettage along the dermal surface of the biopsy was added to the procedure. This modified method resulted in an almost perfect separation of the epidermal and dermal compartments and satisfactory amounts of high-quality RNA were obtained. Hybridization to Affymetrix HG_U133A 2.0 GeneChips showed that ammonium thiocyanate incubation had a minute effect on gene expression resulting in only one significantly downregulated gene (cystatin E/M). We conclude that epidermis can be reproducibly and almost completely separated from the dermis of 4 mm skin biopsies by 30 min incubation in 3.8% ammonium thiocyanate combined with curettage of the dermal surface, producing high-quality RNA suitable for transcriptional analysis. Our refined method of dermo-epidermal separation will undoubtedly prove valuable in the many different settings, where the epidermal and dermal compartments need to be evaluated separately.
Project description:To obtain insights into the global changes of gene expression in the mouse skin in response to epidermal YAP activity, we performed whole transcriptome sequencing of skin tissue of YAP2-5SA-∆C transgenic mice.
Project description:mRNA and miRNA transcription changes during epidermal differentiation and between lesional psoriatic skin and normal skin were analysed
Project description:mRNA and miRNA transcription changes during epidermal differentiation and between lesional psoriatic skin and normal skin were analyzed