Identification of Key Genes Related to Immune-Lipid Metabolism in Skin Barrier Damage and Analysis of Immune Infiltration

Several physical and chemical factors regulate skin barrier function. Skin barrier dysfunction causes many inflammatory skin diseases, such as atopic dermatitis and psoriasis. Activation of the immune response may lead to damage to the epidermal barrier. Abnormal lipid metabolism is defined as abnormally high or low values of plasma lipid components such as plasma cholesterol and triglycerides. The mouse skin barrier damage model was used for RNA sequencing. Bioinformatics analysis and validation were performed. Differently expressed genes (DEGs) related to immune and lipid metabolism were screened by differentially expressed gene analysis, and the enriched biological processes and pathways of these genes were identified by GO-KEGG. The interactions between DEGs were confirmed by constructing a PPI network. GSEA, transcription factor regulatory network, and immune infiltration analyses were performed for the 10 genes. Expression validation was performed by public datasets. The expression of key genes in mouse skin tissue was detected by qPCR. The expression of differentially expressed immune cell markers in the skin was detected by immunofluorescence. Based on the trans epidermal water loss (TEWL) score, the expression of key genes was detected by qPCR before skin barrier injury, at 4h and 7d, and at recovery from injury. Il17a, Il6, Tnf, Itgam, and Cxcl1 were immune-related key genes. Pla2g2f, Ptgs2, Plb1, Pla2g3, and Pla2g2d were key genes for lipid metabolism. Database validation and experimental results revealed that the expression trends of these genes were consistent with our analyses. The research value of these genes has been demonstrated through mouse datasets and experimental validation, and future therapeutic approaches may be able to mitigate the disease by targeting these genes to modulate the function of the skin barrier.