IWR-1 attenuates the promotional effect of IL-36γ in a mouse model of psoriasis.

Background: Psoriasis is a chronic inflammatory skin disease. The Wnt/β-catenin signaling pathway is essential for the regulation of adult stem cells, homeostasis, and tissue regeneration; however, the relationship between this pathway and interleukin (IL)-36γ in the pathogenesis of psoriasis remains unclear.

Methods: In this study, psoriasiform model mice were established using imiquimod (IMQ) induction. Hematoxylin and eosin (H&E) staining was used to evaluate pathological morphologies, while immunohistochemistry was used to verify the expression patterns of β-catenin and the inflammatory factors IL-6, IL-17 A, and interferon (IFN)-γ.

Results: IL-36γ treatment increased psoriasis area and severity index scores, and enhanced proliferation of keratinocytes in IMQ-induced psoriatic mice. The effects of IL-36γ on the severity of psoriasiform lesions and epidermal hyperplasia were partly inhibited by IWR-1, which is an inhibitor of the Wnt/β-catenin signaling pathway. Furthermore, the levels of proinflammatory cytokines and molecules involved in the Wnt/β-catenin signaling pathway in psoriatic mouse skin, including IL-6, IL-17 A, IFN-γ, β-catenin, and Dickkopf-1 (DKK1), were upregulated by treatment with IL-36γ. Consistently, the effects of IL-36γ on the inflammatory response and the Wnt/β-catenin signaling pathway were alleviated by IWR-1.

Conclusions: Taken together, our findings suggested that inhibition of the Wnt/β-catenin signaling pathway may be useful in the alleviation of IL-36γ-induced psoriasis-like lesions.