Figure 2: VEGF increases IL-23 and IL-6 through p38 MAPK signaling in primary human keratinocytes. Primary human keratinocytes (NHEK) were transfected with a VEGF plasmid or a control plasmid at 1 µg/ml and treated with the specific p38 MAPK inhibitor, SB203580 (1µM), for 24h. p38 MAPK inhibition blocked IL-23 and IL-6 mRNA expression in VEGF over-expressing NHEK (as measured by qPCR) (a). Inhibition of CREB1 or Hsp27 by specific siRNA had no effect on VEGF induced IL-23 and IL-6 transcript abundance (as measured by qPCR) (b). Data are means ± SD of a single experiment performed in triplicate and are representative of three independent experiments.