Regulation of angiogenesis and endothelial cell motility by matrix-bound fibroblasts

This study sought to examine the effect of matrix-bound fibroblasts on angiogenesis and endothelial cell motility. Promotion of angiogenesis by matrix-bound fibroblasts was assessed using rat aortic ring and endothelial tube formation assays. Enhancement of human endothelial cell motility by matrix-bound fibroblasts was assessed using cytodex-2 bead and colloidal gold phagokinetic motility assays. Antibody to hepatocyte growth factor/scatter factor (HGF/SF) but not vascular endothelial growth factor (VEGf) decreased fibroblast-enhanced motility of endothelial cells. The promotion of tube formation by matrix-bound fibroblasts was neutralised with antibodies to HGF/SF and VEGf, both known promoters of angiogenesis. HGF/SF presence was detected by ELISA; whilst the presence of VEGf was detected by Western blotting. These data show that matrix-embedded fibroblasts regulate the motility of vascular endothelial cells and enhance angiogenesis, an effect partly attributed to production of angiogenesis-promoting cytokines HGF/SF and/or VEGf.