Fig. 8: NRP1 knockdown inhibits VEGF-A signaling in MEECs expressing ENG.
From: NRP1 interacts with endoglin and VEGFR2 to modulate VEGF signaling and endothelial cell sprouting
MEEC+/+ and MEEC-/- cells were transfected with siRNA to NRP1 or scrambled siRNA (siScrm; control). After 24 h, they were taken for sprouting experiments based on the hanging drop assay as described in Fig. 7. a Typical images of spheroids analysed for sprouts area. The phase contrast images (left) are depicted together with the equivalent images with the outlined sprouts. Scale bar, 100 µm. b Quantification of the sprouting experiments. Silencing NRP1 canceled the VEGF-A-mediated enhanced sprouting in the presence of ENG (MEEC+/+ cells). There was no effect on the ENG-null MEEC-/- cells, where the normal level of sprouting is low to begin with. Data are mean ± SEM of n = 60−80 spheroids per condition (the number of spheroids measured is indicated under each bar) from 5 independent experiments. The area of the sprouts in VEGF-A-stimulated MEEC+/+ was normalized to 100%, and the sprouts area under all other conditions was calculated relative to this value. *p < 0.05; ****p < 10-4 (one-way ANOVA and Bonferroni post-hoc test). ns = not significant.
