Expression of Antimicrobial Peptides in Psoriasiform Mouse Models

Abstract

Background: Psoriasis is a chronic inflammatory skin disease. Despite the current focus on T cells in the pathogenesis of psoriasis, keratinocytes within the psoriatic epidermis are also abnormal in many respects including excessive production of antimicrobial peptides (AMPs). Recently, several studies have used imiquimod (IMQ)- and interleukin (IL)-23-induced mouse models to explore the immunological significance of psoriasis. However, the expression of AMPs in these models remains unclear. Objective: In this study, we evaluated the protein and mRNA expression of AMPs, including cathelicidin-related antimicrobial peptides (CRAMP), mouse β-defensin 3 (mBD3), and psoriasin (S100 calcium-binding protein A7, S100A7) in IMQ- and IL-23-induced psoriasiform mouse models. In addition, we investigated whether ustekinumab, an inhibitor of IL-12 and IL-23, reduces the expression levels of AMPs in these mouse models. Methods: We used IMQ- and IL-23-induced psoriasiform mouse models. Gene and protein expression levels of AMPs were evaluated using quantitative real-time polymerase chain reaction and immunofluorescence staining, respectively. Results: We found that the protein and mRNA expression levels of CRAMP, mBD3, and S100A7 were increased in both mouse models. Ustekinumab decreased AMP expression levels in the two mouse models. Conclusion: These data showed that the elevated expression of AMPs in the epidermis decreased following ustekinumab treatment in both psoriasiform mouse models. Therefore, AMP expression levels may be used as an indicator of treatment efficacy.