(A) Dll4 and Notch1 mRNA expression of endothelial cells before and after laser ablation. A random probe sequence is included as control. Scale bars, 50 μm. Yellow circles indicate locations of laser ablation. Endothelial cells were incubated with GNR-LNA probes for 4 hours before seeding on Matrigel for network formation. After 4 hours, HUVEC networks were ablated with a near infrared laser (0.85 mW/μm2). (B) Dll4 mRNA expression before and after injury for cell networks treated with Y-27632, nocodazole, and Jag1, respectively. Yellow circles indicate locations of laser ablation. (C) Quantification of Dll4 mRNA, Notch1 mRNA, and random expression before and after laser ablation. (D) Comparison of Dll4 mRNA expression before and after laser ablation with the treatments of Y-27632, nocodazole, and Jag1. Data are expressed as mean ± s.e.m. (ns, not significant; *P<0.05, **P<0.01, ***P<0.001; unpaired Student’s t-test).