IL-6 Negatively Regulates IL-22Rα Expression on Epidermal Keratinocytes: Implications for Irritant Contact Dermatitis

Figure 4

IL-6 reduces the effect of IL-22 on keratinocyte differentiation and proliferation. Primary keratinocytes were pretreated with rmIL-6 for 24 hours followed by exposure to 20 ng/ml rmIL-22 for 24 hours (a–f and g–j) or 4 hours (k and l). Immunohistochemical analysis of IL-6KO keratinocyte expression of KRT1 (a–f) or Ki67 (g–j) (green) protein and nuclear staining with DAPI (blue). Representative images are shown. KRT1 expression (k) and Ki67 (l) mRNA expression were analyzed by RT-PCR. Keratinocytes were exposed to rmIL-6 alone in a dose-dependent manner for 4 hours, and KRT1 (m) and Ki67 (n) mRNA were analyzed by RT-PCR. Data are . Significantly different from 0 ng/ml rmIL-6 (, separate experiments).