Figure 1

IFN-γ/TNF-α-induced SOCS1 and SOCS3 expression is higher in psoriatic keratinocytes than in healthy cells. (a) Cultured keratinocytes were prepared from healthy skin or from biopsies taken from uninvolved psoriatic skin. SOCS1 and SOCS3 mRNA levels were detected by real-time PCR analysis in cultured healthy (Healthy KC, □) (n=6) and psoriatic keratinocytes (PS KC, Δ) (n=6) left untreated or 3 h stimulated with IFN-γ and TNF-α and normalized with β-actin mRNA values. Horizontal lines indicate mean values for each experimental group. (b) Protein extracts obtained from healthy (n=6) and psoriatic (n=6) keratinocytes, pre-treated with MG132 for 2 h and, then, stimulated with IFN-γ and TNF-α for different time periods, were subjected to immunoprecipitation for SOCS1 and western blotting analysis to detect SOCS3 or SOCS1 expression. One representative healthy KC and psoriatic KC strain is shown. (c) Immunohistochemistry for SOCS3 and CD3 (both stained in red) was performed on cryosections from biopsies of healthy skin (n=4) (i and v) and psoriatic skin (n=4) including NLS (ii and vi), proximal-to-lesion (Pre-LS) (iii and vii) and LS (iv and viii) zones of evolving plaques. Sections were counterstained with Mayer’s H&E. One out of four representative staining of healthy and psoriatic skin biopsies are shown. Values of P<0.05 (*) and P<0.01 (**) were considered significant