HJD plasma elicits an angiogenic response from ECs that is VEGF-dependent. (A) Endothelial cells incubated with control group A sera for 22 hours showing normal morphology. (B) Endothelial cells incubated with HJD sera for 22 hours revealing the presence of “tube formation” representing blood vessels as indicated by the red arrows. Results replicated 4 times and represent data from 1 experiment. Human umbilical vein endothelial cells grown in DMEM culture medium (10 000/well) were plated on Matrigel-coated 48-well plates with (D) or without (C) preincubation with anti-VEGF antibody (10 μg/mL) and with or without FBS or HJD sera. Images reflected tube formation after 16-hour incubation detected by phase-contrast microscopy (original magnification ×40). Representative results from 4 experiments. Quantitative assessment of mean and total tube lengths and branch points using Metamorph software Version 40002 (Molecular Devices) revealed an 84% reduction in total tube length (SEM). *P < .001. (E) An 82% reduction in mean (SEM) tube length (data not shown). P < .001. A 93% reduction in mean (SEM) branch points. P < .001. (F) Representative results from 3 experiments. Migration across a transwell barrier was induced by VEGF and HJD serum and abrogated by anti-VEGF and anti–SDF-1 antibody. When human umbilical vein endothelial cells were plated on 24-well plates with or without VEGF, HJD serum, anti-VEGF blocking peptide, or anti-SDF-1 antibody, a 55% reduction in human umbilical vein endothelial cell migration with anti-VEGF antibody and a 60% reduction with anti-SDF-1 antibody (P < .01) was observed. There was no additive effect of anti-VEGF and anti–SDF-1 antibodies. (G) Results are expressed as a percent of the control, which is human umbilical vein endothelial cells grown in the presence of VEGF. Representative results from 3 experiments.