Figure 1: Human keratinocytes over-expressing VEGF increase IL-23 and IL-6. Immunohistochemical analyses demonstrate increased VEGF and IL23 (IL- 23p19) protein expression in epidermal keratinocytes in lesional psoriatic skin in vivo (a). In vitro, primary human keratinocytes (NHEK) transfected with a VEGF expression plasmid show increased IL-23 and IL-6 mRNA abundance compared to NHEK transfected with a control plasmid (b). Data are means ± SD of a single experiment performed in triplicate and are representative of two to three independent experiments. In (c) induction of IL-23p19 protein in VEGF over-expressing NHEK was confirmed by dot blot. Increased release of IL-6 into cell culture supernatants could be demonstrated by ELISA.