Figure 1: BMP signalling promotes lateral branching of angiogenic sprouts.
From: Notch regulates BMP responsiveness and lateral branching in vessel networks via SMAD6
(a,b) HUVEC 3D sprouting assay with BMP6, representative of three independent experiments, stained with phalloidin (actin) and depth encoded. (c,d) Quantification of (c) branches per mm (n=7 control and 10 BMP6 beads) and (d) branch angle (n=43 control and 133 BMP6 angles). Error bars, mean±95% confidence interval (CI). **P≤0.01; ***P≤0.001 by Student’s t-test. (e,f) Sprouting HUVEC visualized with phalloidin (actin) and DRAQ7 (DNA). (g) Tip nuclei/total nuclei per field, representative of three independent experiments (n=9 control and 7 BMP6 sprouts). Error bars, mean±95% CI. **P≤0.01 by Student’s t-test. (h–k) HUVEC 3D sprouting assay 6 h post-BMP6 treatment, visualized for nuclear pSMAD1/5, phalloidin (actin) and DRAQ7 (DNA). Images are three-channel compressed z-stacks (h,i) or single-channel compressed z-stack heat maps of pSMAD1/5 staining intensity (j,k). Scale bar, 50 mm. (l) Quantification of mean pSMAD1/5 fluorescence intensity per nucleus, representative of 2 independent experiments (n=13 control tip, 50 control stalk, 15 BMP6 tip, and 58 BMP6 stalk EC). Error bars, mean±95% CI. NS, not significant; ***P≤0.001 and ****P≤0.0001 by one-way analysis of variance with Tukey’s post-hoc test. (m) Best-fit correlation (solid line) with 95% CI intervals (filled areas) of indicated parameters. *P≤0.05 by linear regression.
