The inhibition of capillary-like tube formation by PAR1-activating peptide can be reversed by increasing concentrations of VEGF. 10⁴ ECFCs/well were plated onto Matrigel matrix in tube formation assay buffer (i.e. EBM-2 medium containing 2% FBS).

<p>Cells were cultured with 50 µM scrambled control peptide or 50 µM PAR1-activating peptide in the absence or presence VEGF (50 and 100 ng/ml) (A and B) or FGF (25, 50 and 100 ng/ml) (C). 4 hours after seeding, images were collected and representative examples of three independent experiments are shown in (A). The number of tubes per image was calculated using the Angiogenesis Analyzer plugin for ImageJ. Means ± SEM from three independent experiments are shown in (B) and (C). Statistical significance was tested by one-way ANOVA with Bonferroni post-test (* = p<0.05; ** = p<0.01).