Figure 2.

ALK1 signaling controls Dll4 expression. (A) HUVECs were treated or not (CTRL) for 24 h in complete medium (conditioned for 2 days) with ALK1-Fc (1 μg/ml) or BMP9 (10 ng/ml). Cell extracts were analyzed by WB using antibodies directed against the indicated proteins. (B) Densitometric analyses and quantification of Dll4, pSmad1/5/8, and ID1 relative levels in n = 4 independent experiments, as in (A). Data represent mean ± SEM; **P < 0.01, ***P < 0.001, ****P < 0.0001; one-way ANOVA, Dunnett's multiple comparisons test.