Pharmacologic inhibition of multiple signaling pathways inhibits VEGF induction of MEF2-dependent transcription. (A) HRECs were cotransfected with 3X-MEF2-Luc and pRL-SV40, as in Figure 4A. Thirty minutes before VEGF addition, cells were treated with cyclosporin (1 μM), KN93 (3 μM), or SB203580 (20 μM). Cells were harvested 16 hours after VEGF treatment and assayed for luciferase activity. Data are presented as in Figure 4. There was no statistically significant difference in relative luciferase activity between control and cyclosporin, KN-93, or SB203580. (B) Thirty minutes before VEGF addition, cells were treated with calphostin C (1 μM) or PD98059 (20 μ M). Luciferase activity was assayed 16 hours after VEGF treatment. *P < 0.05 and ***P < 0.001 versus control.