Figure 1

Monomeric IgE induces secretion of VEGF in BMMCs through a mechanism that requires Fyn. ( A ) Pharmacological characterization of IgE-induced VEGF secretion in MC. Two million BMMCs were pre-incubated with vehicle, Actinomicyn D (Act D; 5 μg/ml), Brefeldin A (BFA; 5μg/ml), Tetanus toxin (TTx; 10 ng/ml) and PP2 (10 μM) for 15 min in BMMC media. Then, cells were stimulated with 1000 ng of IgE for 8 h at 37°C. VEGF in cell supernatants was quantified by ELISA. ( B ) Role of different Src family kinases on IgE-induced VEGF secretion in MC. Two million BMMCs derived from WT, Fyn −/− and Lyn −/− mice were incubated with different amounts of IgE at 37°C for eight hours. Supernatants were collected and VEGF was determined by ELISA. ( C ) Time-course of VEGF secretion after the addition of IgE. Two million BMMCs were incubated in cell culture media containing 1000 ng/million cells of IgE at 37°C and supernatants were collected at different times after stimulation. VEGF was determined by ELISA. All results are shown as the mean ± SEM (n = 3-12). *, P < 0.05 compared with basal or time 0, &, P < 0.05 compared with IgE treatment, #, P < 0.05 compared to WT. One way ANOVA post hoc Student-Newman-Keuls ( A ). Two way ANOVA post hoc Student-Newman-Keuls ( B and C ).