Pharmacologic inhibition of Il6st/gp130 improves dermatological inflammation and pruritus

Chronic dermatitis is a disease with large unmet need for pharmacological improvement. Dermatitis conditions are maintained and exacerbated by various cytokine actions in the context of inflammation. Interleukin 6 signal transducer (Il6st), also known as glycoprotein 130 (Gp130), is a key component for surface reception of a multitude of cytokines and transduction and amplification of their pro-inflammatory signals. We hypothesized accordingly that pharmacological inhibition of Il6st can alter dermatitis pathology. Treatment with SC-144 and bazedoxifene, two representative small molecule Il6st inhibitors with different binding modes led to moderate but significant improvement of skin conditions in a 1-chloro-2,4-dinitrobenzene animal model. Part of cytokine expressions indicating the dermatological index were normalized particularly when treated with SC-144. Pruritic behaviors were blunted, also possibly giving limited contribution to disease improvement. In psoriatic skin and itch of an imiquimod animal model, those two treatments appeared to be relatively moderate. Collectively, pharmacological inhibition of Il6st seems to lessen pathological irritation. Inversely, this experimental attempt newly implies that Il6st participates in pathological mechanisms. In conclusion, we suggest Il6st as a novel target for improving dermatitis, and that agents with suitable efficacy and safety for its modulation are translatable.