SDR9C7 catalyzes critical dehydrogenation of acylceramides for skin barrier formation
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA559537 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:SDR9C7 encodes an orphan short-chain dehydrogenase/reductase recently found mutated in ichthyosis. In a patient with SDR9C7 mutation and a mouse Sdr9c7 knockout model we show loss of covalent binding of epidermal ceramides to protein, a structural fault in the barrier. For reasons unresolved, protein binding requires lipoxygenase-catalyzed transformations of linoleic acid (18:2) esterified in ω-O-acylceramides. In Sdr9c7-/- epidermis, quantitative LC-MS assays revealed almost complete loss of a species of ω-O-acylceramide esterified with linoleate-9,10-trans-epoxy-11E-13-ketone; other acylceramides related to the lipoxygenase pathway were in higher abundance. Recombinant SDR9C7 catalyzed NAD-dependent dehydrogenation of linoleate 9,10-trans-epoxy-11E-13-alcohol to the corresponding 13-ketone, while ichthyosis mutants were inactive. We propose, therefore, that the critical requirement for lipoxygenases and SDR9C7 is in producing acylceramide containing the 9,10-epoxy-11E-13-ketone, a reactive moiety known for its non-enzymatic coupling to protein. This suggests a novel mechanism for coupling of ceramide to protein and provides important insights into skin barrier formation and pathogenesis.
2019-11-07 | GSE135643 | GEO
Project description:The corneocyte lipid envelope, composed of covalently bound ceramides and fatty acids, is important to the integrity of the permeability barrier in the stratum corneum, and its absence is a prime structural defect in various skin diseases associated with defective skin barrier function. SDR9C7 encodes a short-chain dehydrogenase/reductase family 9C member 7 (SDR9C7) recently found mutated in ichthyosis. In a patient with SDR9C7 mutation and a mouse Sdr9c7-KO model, we show loss of covalent binding of epidermal ceramides to protein, a structural fault in the barrier. For reasons unresolved, protein binding requires lipoxygenase-catalyzed transformations of linoleic acid (18:2) esterified in ω-O-acylceramides. In Sdr9c7-/- epidermis, quantitative liquid chromatography-mass spectometry (LC-MS) assays revealed almost complete loss of a species of ω-O-acylceramide esterified with linoleate-9,10-trans-epoxy-11E-13-ketone; other acylceramides related to the lipoxygenase pathway were in higher abundance. Recombinant SDR9C7 catalyzed NAD+-dependent dehydrogenation of linoleate 9,10-trans-epoxy-11E-13-alcohol to the corresponding 13-ketone, while ichthyosis mutants were inactive. We propose, therefore, that the critical requirement for lipoxygenases and SDR9C7 is in producing acylceramide containing the 9,10-epoxy-11E-13-ketone, a reactive moiety known for its nonenzymatic coupling to protein. This suggests a mechanism for coupling of ceramide to protein and provides important insights into skin barrier formation and pathogenesis.
| S-EPMC6994155 | biostudies-literature
Project description:We generated KA mutant mice (Krt14-CreERT + ABCA12-flox/flox) and controls (ABCA12-flox/flox) that enabled us to assess the effects of deleting a critical barrier gene, ABCA12, in the skin epidermis following tamoxifen treatment. These studies identified numerous differentially expressed genes (DEGs) upon barrier disruption/ABCA12 deletion, including compensatory upregulation of genes involved with epidermal differentiation and barrier function. Overall, this data-set provides a global view of molecular changes that occur in adult mouse skin following barrier perturbation.
2024-05-20 | GSE254889 | GEO
Project description:Essential to terrestrial life is the formation of a competent skin barrier that prevents desiccation and entry by harmful substances. A tightly orchestrated series of cellular changes is required for the proper formation of the epidermal permeability barrier. These changes occur in the context of the commensal skin microbiota. Using germ free mice and antibiotic depletion models, we demonstrate the microbiota is necessary for proper differentiation and repair of the barrier. These effects were mediated by keratinocyte signaling through the aryl hydrocarbon receptor (AHR), a xenobiotic receptor that also regulates epidermal differentiation. Murine skin lacking keratinocyte AHR was more susceptible to infection by S. aureus and increased pathology in a model of atopic dermatitis. Topical colonization with a defined consortium of human skin commensals restored barrier competence in germ free skin and during epicutaneous sensitization; these effects were dependent on keratinocyte AHR. We reveal a fundamental role for the commensal skin microbiota in directing skin barrier formation and repair through the AHR, with far-reaching implications for the numerous skin disorders characterized by disrupted epidermal differentiation and/or barrier competence.
2021-03-31 | GSE162925 | GEO
Project description:The epidermis, outermost layer of the skin, forms a barrier and is involved in innate and adaptive immunity in an organism. Keratinocytes participate in all these three protective processes. However, a regulator of keratinocyte protective responses against external dangers and stresses remains elusive. We found that upregulation of the orphan gene 2610528A11Rik was a common factor in the skin of mice with several types of inflammation. In the human epidermis, peptide expression of G protein-coupled receptor 15 ligand (GPR15L), encoded by the human ortholog C10orf99, was highly induced in the lesional skin of patients with atopic dermatitis or psoriasis. C10orf99 gene transfection into normal human epidermal keratinocytes (NHEKs) induced the expression of inflammatory mediators and reduced the expression of barrier-related genes. Gene ontology analyses showed its association with translation, mitogen-activated protein kinase (MAPK), mitochondria, and lipid metabolism. Treatment with GPR15L reduced the expression levels of filaggrin and loricrin in human keratinocyte 3D cultures. Instead, their expression levels in mouse primary cultured keratinocytes did not show significant differences between the wild-type and 2610528A11Rik deficient keratinocytes. Lipopolysaccharide-induced expression of Il1b and Il6 was less in 2610528A11Rik deficient mouse keratinocytes than in wild-type, and imiquimod-induced psoriatic dermatitis was blunted in 2610528A11Rik deficient mice. Furthermore, repetitive subcutaneous injection of GPR15L in mouse ears induced skin inflammation in a dose-dependent manner. These results suggest that C10orf99/GPR15L is a primary inducible regulator that reduces the barrier formation and induces the inflammatory response of keratinocytes.
2022-02-28 | GSE189751 | GEO
Project description:Atopic dermatitis (AD) is a heritable inflammatory disease, characterised by skin barrier dysfunction. Genome-wide association studies (GWAS) have identified molecular targets with relevance for drug development, but the strongest genetic association, FLG, has not yet been successfully targeted in atopic disease. An AD-associated locus on chromosome 11q13.5 lies between two genes - EMSY and LRRC32 - but the functional mechanisms leading to AD are unclear. We applied a combination of genomic and molecular analytical techniques followed up in patient biopsies, to investigate pathomechanisms at this GWAS locus. Chromosome conformation capture data in keratinocytes shows interaction of the intergenic region in threedimensional space with EMSY. siRNA-mediated knockdown of EMSY in skin organoid culture leads to enhanced development of barrier function, measured by water evaporation and dye penetration. Global proteomic analysis of skin organoids with EMSY knockdown shows increased expression of structural and functional proteins, confirmed by histological and ultrastructural features. Lipid analysis shows an increase in ceramides known to be reduced in AD. Conversely, over-expression of EMSY in primary human keratinocytes leads to a reduction in biomarkers of barrier formation. Finally, skin biopsy samples from patients with AD show greater EMSY staining in the nucleus, consistent with increased functional effect of this DNAbinding protein. Together our findings demonstrate an important role for EMSY in transcriptional regulation and skin barrier formation, supporting EMSY inhibition as a therapeutic approach for AD.
2019-06-24 | PXD014088 | Pride
Project description:C10orf99/GPR15L Regulates Proinflammatory Response of Keratinocytes and Barrier Formation of the Skin
| PRJNA784408 | ENA
Project description:Background: Atopic dermatitis (AD) is characterized by skin barrier dysfunction. The impact of targeted therapies on skin barrier function and associated barrier protein changes remains not fully identified. Objective: To investigate the skin barrier function and proteomics in AD before and after different targeted therapies. Method: 15 healthy controls and 29 adult patients with moderate-to-severe AD were enrolled. AD patients were randomized into two groups. One group received dupilumab (N = 14) and the other received abrocitinib (N = 15). Clinical assessments and skin barrier parameters (transepidermal water loss [TEWL] and hydration) were measured at baseline, 4 weeks, and 12 weeks of treatment. Skin tape strips were collected for four-dimensional data-independent acquisition-based proteomics. Results: Both therapies improved skin barrier function, with abrocitinib showing greater effects on decreasing TEWL in the non-lesional skin. The proteomic analysis identified 1237 lesional and 785 non-lesional differentially expressed proteins (DEPs) between AD patients and healthy controls, especially in pathways related to ceramide metabolism, neurobiology, and keratinocyte biology. Treatment with abrocitinib resulted in more DEPs and significantly upregulated proteins associated with the epidermal barrier while downregulating immunological and itch-related proteins. It also increased key barrier proteins (filaggrin-2 and loricrin) in lesional skin, which was not shown in the dupilumab group. Both treatments regulated specific proteins in non-lesional skin, such as grancalcin and phospholipase D3. Conclusion: The study suggests that both targeted therapies improve the skin barrier function in AD, but they have different effects on barrier proteins, with abrocitinib having stronger effects.
2025-04-19 | PXD055561 | Pride
Project description:Hair follicles modulate skin barrier function
| PRJNA1072231 | ENA
Project description:The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor involved in adaptive cell functions, and highly active in the epidermis. AhR-ligands can accelerate keratinocyte differentiation, but a precise role for AhR in the skin barrier is unknown. We here show that transepidermal water loss (TEWL), a parameter of skin barrier integrity, is high in AhR-deficient (AhR-KO) mice. Experiments with conditionally AhR-deficient mouse lines identified keratinocytes as the major responsible cell population for high TEWL. Electron microscopy showed weaker inter-cellular connectivity in the epidermis of keratinocytes in AhR-KO mice, and gene expression analysis identified many barrier-associated genes as AhR targets. Moreover, AhR-deficient mice had higher inter-individual differences in their microbiome. Interestingly, removing AhR-ligands from the diet of wild-type mice mimicked AhR-deficiency regarding the impaired barrier. Vice versa, re-addition of the plant-derived ligand indole-3-carbinol (I3C) rescued the barrier deficiency even in aged mice. Our results suggest that functional AhR expression is critical for skin barrier integrity and that AhR represents a molecular target for the development of novel therapeutic approaches for skin barrier diseases, including dietary intervention.
2016-08-31 | GSE80273 | GEO