Cimifugin ameliorates atopic dermatitis through modulation of the OGT/IL-4 axis and suppression of O-GlcNAcylation and downregulate IL-4

Atopic dermatitis (AD) is a prevalent inflammatory skin disorder where interleukin-4 (IL-4) plays a central pathogenic role. The post-translational modification O-GlcNAcylation, catalyzed by O-GlcNAc transferase (OGT), regulates protein stability and function, but its involvement in AD is unclear. This study aimed to investigate whether cimifugin, a natural chromone, alleviates AD by targeting the OGT/IL-4 axis. An in vitro AD model was established using TNF-α/IFN-γ-stimulated HaCaT keratinocytes, treated with cimifugin. Molecular docking predicted cimifugin-OGT interaction. OGT overexpression, IL-4 knockdown, co-immunoprecipitation, and site-directed mutagenesis were employed to probe mechanisms. Cimifugin treatment reduced inflammation, apoptosis, and the secretion of key cytokines/chemokines in stimulated HaCaT cells. Molecular docking suggested a binding potential between cimifugin and OGT, which was associated with decreased global O-GlcNAcylation and OGT protein levels. OGT overexpression abolished cimifugin’s protective effects. OGT directly interacted with and stabilized IL-4 via O-GlcNAcylation at threonine 54. Knockdown of IL-4 rescued the adverse effects caused by OGT overexpression. In mice, cimifugin significantly ameliorated DNCB-induced skin inflammation, itching, epidermal hyperplasia, and reduced levels of IL-4, OGT, and O-GlcNAcylation in lesional skin. Cimifugin alleviates AD via interference with OGT-mediated O-GlcNAcylation and destabilization of IL-4. This identifies the OGT/IL-4 axis as a novel therapeutic target for AD.