Identification of key pathways and genes in psoriasis via gene microarray analysis.

Psoriasis is a common chronic inflammatory, immune-mediated skin disease with a high incidence worldwide. It is a multifactorial disease and its exact pathogenesis has remained largely elusive. The purpose of the present study was to uncover the key pathways and genes associated with the incidence of psoriasis. Gene expression profiles (dataset no. GSE13355) were downloaded from Gene Expression Omnibus. Differentially expressed genes between skin samples from patients with lesional psoriasis or non‑lesional psoriasis and those of normal healthy controls were identified using Bioconductor version 2.13 based in R. Kyoto Encyclopedia of Genes and genomes (KEGG) pathways significantly enriched in patients with lesional psoriasis were identified using gene set enrichment analysis (GSEA). Key KEGG pathways were then identified using leading-edge analysis of the results of GSEA. Differentially expressed genes involved in the significantly enriched KEGG pathways were considered as key genes. Several KEGG pathways which are known to be associated with lesional psoriasis, including autoimmune thyroid disease signaling, natural killer cell-mediated cytotoxicity signaling, as well as several novel pathways, including FCγR-mediated phagocytosis and neurotrophin signaling pathway, were identified. Several verified and novel genes were also got. The present study revealed key pathways and genes associated with psoriasis, which may serve as important biomarkers for the diagnosis and treatment of psoriasis.