Interleukin-1 family members are enhanced in psoriasis and suppressed by vitamin D and retinoic acid

Interleukin (IL)-1 family comprise 11 members that plays an important role in immune regulation and inflammatory process. Retinoids exert complex effects on the immune system, having anti-inflammatory effects in chronic dermatological diseases. Vitamin D (vitD) and analogs have been shown to suppress TNF-?-induced IL-1? in human keratinocytes (KCs). In the present study we investigated IL-1 family members in psoriasis and the effects of vitD and retinoic acid (RA) on these members. We analyzed IL-1 family members gene expression in psoriatic skin and in ex vivo skin organ culture exposed to TNF-?, IL-17 or broadband UVB; afterwards treatment with vitD or RA was performed and IL-1 family members mRNA was evaluated. Similarly, KCs were stimulated with IL-17 and subsequently treated with vitD. IL-1 family members were enhanced in psoriatic skin and in ex vivo skin organ cultures after pro-inflammatory stimuli (TNF-?, IL-17 and UVB). RA and vitD were able to suppress this enhancement.