Identifying immune cell infiltration and constructing a ceRNA network to explore novel diagnostic biomarkers and therapeutic targets in atopic dermatitis

Abstract Background Atopic dermatitis (AD) is a chronic, recurrent, itchy skin disease characterized by inflammatory imbalance. Objective To identify novel diagnostic biomarkers and potential therapeutic targets for AD. Methods Two test microarray datasets (GSE63741, GSE60709) and a validated dataset (GSE75890) were downloaded from the Gene Expression Omnibus database. We explored the hub genes by analysis of immune coexpression and protein–protein interaction. We also constructed a competing endogenous RNA (ceRNA) network to explore the new therapeutic targets. We estimated immune cell types by ImmucellAI and the relevance between hub genes and immune cells. Functional analysis was also performed. Finally, we validated the hub genes through real-time quantitative PCR (RT-qPCR), immunohistochemistry (IHC) and western blotting (WB). Results A significantly altered proportion of 24 immune-cell types was found between healthy controls (HCs) and AD patients, and each of the hub genes was significantly correlated with the main infiltrating cells. Expression of S100A7 , APOE and KRT15 in skin tissues differed significantly between AD patients and HCs. hsa-miR-365a-3p and NPSR1-AS1 were identified as potential new therapeutic targets of AD. Conclusion S100A7 , APOE and KRT15 were associated with immune cells and could become new diagnostic biomarkers and hsa-miR-365a-3p and NPSR1-AS1 might be new therapeutic targets of AD.