Figure 3

Fyn is involved in IgE-induced VEGF protein translation and in IRES-dependent translation. ( A ) IgE-induced VEGF synthesis is sensitive to cicloheximide. Two million BMMCs were pre-incubated with cycloheximide (CHX) for 15 min in cell culture media at 37°C. Then, cells were stimulated with 1000 ng of IgE for eight hours. VEGF was determined in cell supernatants. Results are shown as the mean ± SEM (n = 3). *, P < 0.05 compared with basal, #, P < 0.05 compared with IgE-treated cells. &, P < 0.05 compared with WT cells. Two way ANOVA post hoc Student-Newman-Keuls. ( B ) Effect of IgE on the activation of translational regulators. Two million BMMCs were stimulated with 1000 ng of IgE for 0, 15, 30 and 60 min in cell culture media. Western blot analysis of S6 and 4E-BP1 protein phosphorylation induced by IgE in MC. β-actin was used as a loading control. Samples were normalized to their respective β-actin loading control and data are expressed as arbitrary units. ( C ) Quantification of S6 and 4E-BP1 phosphorylation in WT BMMCs. ( D ) Quantification of S6 and 4E-BP1 phosphorylation in Fyn −/− BMMCs. Mean ± SEM (n = 3). *, P < 0.05 compared with 0 ng of IgE; &, P < 0.05 compared with WT. Two way ANOVA post hoc Student-Newman-Keuls.