Proliferation and migration activities of fibroblast growth factor-2 in endothelial cells are modulated by its direct interaction with heparin affin regulatory peptide

Biochimie. 2014 Dec:107 Pt B:350-7. doi: 10.1016/j.biochi.2014.10.002. Epub 2014 Oct 12.

Abstract

Angiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. In normal or pathological angiogenesis, angiogenic growth factors activate cognate receptors on endothelial cells. Fibroblast growth factor-2 (FGF-2) and heparin affin regulatory peptide (HARP) are two heparin-binding growth factors and were described for their pro-angiogenic properties on human umbilical endothelial cells (HUVEC). We now show that HARP acts as a mediator of FGF-2's stimulatory effects, since it is able to inhibit the proliferation and migration of HUVEC induced by FGF-2. We demonstrate by ELISA and optical biosensor binding assay that HARP and FGF-2 interact through direct binding. We have adapted a previously developed structural proteomics method for the identification of residues involved in protein-protein interactions. Application of this method showed that two sequences in HARP were involved in binding FGF-2. One was in the C-thrombospondin type 1 repeat (C-TSR-1) domain and the other in the C-terminal domain of HARP. The identification of these regions as mediating the binding of FGF-2 was confirmed by ELISA using synthetic peptides, which are as well mediators of FGF-2-induced proliferation, migration and tubes formation on HUVEC in vitro. These results imply that besides a regulation of the proliferation, migration and angiogenesis of HUVEC by direct interaction of FGF-2 with its receptors, an alternative pathway exists involving its binding to growth factors such as HARP.

Keywords: Growth factors; Interaction; Migration; Proliferation; Protect and label.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Biosensing Techniques
  • Carrier Proteins / metabolism*
  • Carrier Proteins / pharmacology
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cytokines / metabolism*
  • Cytokines / pharmacology
  • Enzyme-Linked Immunosorbent Assay
  • Fibroblast Growth Factor 2 / metabolism*
  • Fibroblast Growth Factor 2 / pharmacology
  • Human Umbilical Vein Endothelial Cells / drug effects
  • Humans
  • Molecular Sequence Data
  • Neovascularization, Physiologic
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / pharmacology

Substances

  • Carrier Proteins
  • Cytokines
  • Recombinant Proteins
  • Fibroblast Growth Factor 2
  • pleiotrophin