ABSTRACT
BACKGROUND: Psoriasis is a chronic inflammatory skin disease with an incidence of 0.5~3% of the worldwide population. The pathogenesis of psoriasis is related to dysregulated keratinocyte function and immune reactions. Notably, genetic factors are considered important etiological contributors. Globally, several researchers have recently performed genome-wide association studies (GWAS) to identify the genes related with psoriasis. OBJECTIVE: We aimed to investigate the expression pattern of 2 candidate genes that were identified by GWAS. These include interleukin 28 receptor alpha (IL28RA) and CUB and Sushi multiple domains 1 (CSMD1). METHODS: We applied imiquimod cream to develop a psoriasis-like mouse model and obtained skin tissue. We performed immunohistochemistry to detect the expression of IL-28A and CSMD1. RESULTS: IL28RA expression increased at an early time point such as 1 day after the topical application of 5% imiquimod cream. However, its expression returned to baseline levels 2 weeks after the topical application of imiquimod cream. CSMD1 expression also increased after the topical application of imiquimod, with increased expression particularly observed in the upper epidermal layer. Notably, CSMD1 expression decreased 7 days after imiquimod cream application. CONCLUSION: These results suggest that IL28RA and CSMD1 may play key roles in the pathogenesis of psoriasis.