No Evidence for a Functional Role of Bi-Directional Notch Signaling during Angiogenesis
Figure 5
Notch ligand ICDs do not affect sprouting angiogenesis.
NOTCH1-ICD or ligand-ICD expressing HUVEC were cultured as spheroids in collagen and treated with 25 ng/ml VEGF, FGF-2 or PBS as control. The cumulative length of all sprouts was measured. Data are presented as mean cumulative sprout length per spheroid +SD. n = 3 independent experiments with 10 spheroids per condition. (A,B) Expression of Citrine-tagged ligand-ICDs or such without this tag did not significantly alter sprouting behavior. (C) The average sprout length was slightly but not significantly (p>0.05 in all cases) reduced after ligand-ICD expression. The average number of capillary sprouts was not altered. (D) NOTCH1-ICD expression prevents VEGF and FGF2-induced sprouting angiogenesis. However, this was not significantly affected by co-expression of ligand-ICDs. *, p<0.05. n.s., not significant.