ERK inhibitor JSI287 alleviates imiquimod-induced mice skin lesions by ERK/IL-17 signaling pathway

Many studies confirmed that the over-activation of RAF-MEK-ERK signaling pathway plays a central role in human cancers. To avoid drug resistance during cancer treatment, many researchers focused on the study of the downstream therapeutic target of RAF-MEK-ERK signaling pathway. Therefore, ERK1/2 became a hot anticancer target. It has been shown that ERIC phosphorylation could activate Th17 cells and therefore induce inflammatory diseases. Due to these results, inhibition of ERIC, as a potential drug target, could provide a solution for autoimmune diseases, especially T cell mediated diseases. In this study, a small synthetic molecule JSI287 was found with the function of alleviating IMQ-induced mice skin lesions through ERK/IL-17 signaling pathway during the screening of small molecule databases targeting ERIC. The results showed that JS1287 small molecule alleviated epidermal thickness, epidermis congestion, edema and inflammatory cell infiltration, decreased release of inflammatory cytokines of IL-6, IL-12 and IL-17A, and further regulated the mRNA expression of ATF1 and protein expression of ERK1/2 in IMQ-induced skin lesions. Our study suggested that ERK inhibitor JSI287 could be a promising candidate for psoriasis treatment.