Selective Immunomodulation of Inflammatory Pathways in Keratinocytes by the Janus Kinase (JAK) Inhibitor Tofacitinib: Implications for the Employment of JAK-Targeting Drugs in Psoriasis

Figure 2

Tofacitinib regulates IFN-γ- and IL-22- but not TNF-α-induced signaling molecules in psoriatic keratinocytes. Protein extracts obtained from psoriatic keratinocytes pretreated with 5 μM tofacitinib or vehicle alone and then stimulated or not with IFN-γ, IL-22, or TNF-α for 20 min were used on a PathScan intracellular signaling array, which allows the simultaneous detection of 18 signaling molecules when phosphorylated or cleaved. They include ERK1/2, STAT1, STAT3, Akt (Thr308 and Ser473 phosphorylation), AMPKa, mTOR, HSP27, Bad, p53, p38, SAPK/JNK, PARP, and caspase 3. Developed slides were acquired at ChemiDoc system. Graphs represent densitometric analyses of the indicated proteins. Data are expressed as mean ± SD fold induction (F.I.) calculated relatively to the untreated samples, which were given a value of 1. Protein panel was analysed in two assays with two different keratinocyte strains. Each value was normalized to an internal positive control. for samples treated with tofacitinib vs. untreated, in the presence of cytokines.