Fig. 3.

Ephrin-induced VEGF-A upregulation requires Erk phosphorylation. A: EphrinB2 (EFNB2) and EphB4 stimulation of HSC increased Erk phosphorylation compared with vehicle, whereas Akt phosphorylation (pAKT-Ser473 and pAKT-Thr308) was unchanged (0–4 μg/ml; n = 3 separate experiments; pThr308-to-total Akt ratio from densitometric analysis is shown below the Western blot). B: U0126 (10 μm) attenuated the increase in Erk phosphorylation as assessed by Western blot. Total Erk served as a protein loading control. PDGF stimulation was used as a positive control for Erk and Akt activation. C: U0126 (10 μm) decreased VEGF mRNA levels in EphrinB2- and EphB4-stimulated cells compared with vehicle (*P < 0.05).