Reduction of Methyltransferase-like 3-Mediated RNA N6-Methyladenosine Exacerbates the Development of Psoriasis Vulgaris in Imiquimod-Induced Psoriasis-like Mouse Model

N6-methyladenosine (m(6)A) methylation is the most pervasive and intensively studied mRNA modification, which regulates gene expression in different physiological processes, such as cell proliferation, differentiation, and inflammation. Studies of aberrant m(6)A in human diseases such as cancer, obesity, infertility, neuronal disorders, immune diseases, and inflammation are rapidly evolving. However, the regulatory mechanism and physiological significance of m(6)A methylation in psoriasis vulgaris are still poorly understood. In this study, we found that m(6)A methylation and Methyltransferase-like 3 (METTL3) were both downregulated in psoriatic skin lesions and were negatively correlated with Psoriasis Area and Severity Index (PASI) scores. Inhibiting m(6)A methylation by knocking down Mettl3 promoted the development of psoriasis and increased its severity in imiquimod-induced psoriasis-like model mice. Our results indicate a critical role of METTL3- mediated m(6)A methylation in the pathogenesis of psoriasis vulgaris.