Figure 2.

Different cytokines are able to activate their canonical signaling pathways in IECs. (A) In Caco-2 cells, IFN-γ induced the phosphorylation of STAT1 without affecting STAT6 or STAT3. (B) IL-4 induced the phosphorylation of STAT6 without affecting STAT1 or STAT3. (C) IL-6 was used as a positive control and increased STAT3 as well as STAT1 phosphorylation. (D–E) Stimulation with PGE₂ induced p-PKA and p-CREB expression in Caco-2 cells without any signs of STAT3 phosphorylation, demonstrating specificity of the results. (F) Cytokine mRNA expression in colonic biopsies. The graph represents the average IL-8 and IL-1β mRNA relative expression (deltaCt) of whole colonic biopsies from healthy individuals and inactive and active UC patients. The error bar equals standard error of the mean (SEM). *p < 0.001, control compared with active UC.