Abstract: Objective: The expression of microRNAs (miRNAs) in serum of children with atopic dermatitis (AD) was analyzed by bioinformatics, and the function and signal pathways of target genes in the pathogenesis of AD were discussed. Methods: Data of miRNAs in serum of 8 AD children and 8 healthy volunteers were downloaded from Gene Expression Omnibus (GEO). The differentially expressed miRNAs were screened using R3.4.1 software package. The most differentially expressed microRNA selected for subsequent analysis was verified using fluorescence quantitative PCR. The target genes were predicted on Mir Tarbase database of which the GO function and KEGG signal pathway were enriched by cytoscape 3.5.1 software and its plug-ins ClueGO and CluePedia. Results: Seven miRNAs differentially expressed in the serum of children with AD were screened, including 2 up-regulated miRNAs and 5 down-regulated miRNAs. The most differentially expressed miRNA-126 was selected for further analysis. Fluorescence quantitative PCR showed that the expression of microRNA126 in serum of children with AD was lower than that of healthy children. The database predicted 110 target genes. GO analysis showed that the target genes mainly involved in regulation of vascular permeability, RAC protein signal transduction, endothelial cell proliferation, matrix-dependent cell proliferation, activation of MAPKK activity, phosphoprotein binding and so on. KEGG analysis indicated that target genes enriched in 17 signaling pathways, such as FoxO signaling pathway, NF-κB signaling pathway, B cell receptor signaling pathway, VEGF signaling pathway. Conclusion: Bioinformatics may effectively analyze the microRNAs data of the serum in children with AD, and provide evidence for further research on the mechanism of the disease and potential drug treatment targets.

Key words: bioinformatics analysis, microRNA, atopic dermatitis