Endothelial cell surface vimentin binding peptide induces angiogenesis under hypoxic/ischemic conditions

• Published in: Microvascular research 2011-11, Vol.82 (3), p.221-226
• Main Authors: Glaser-Gabay, Leticia, Raiter, Annat, Battler, Alexander, Hardy, Britta
• Format: Article
• Language: English
• Subjects: Angiogenesis Inducing Agents - administration & dosage; Angiogenesis Inducing Agents - metabolism; Angiogenesis Inducing Agents - pharmacology; Animals; Cell Adhesion - drug effects; Cell Hypoxia; Cell Membrane - drug effects; Cell Membrane - metabolism; Cell Proliferation - drug effects; Cells, Cultured; Disease Models, Animal; Female; Fibronectins - metabolism; Flow Cytometry; Hindlimb; Human Umbilical Vein Endothelial Cells - drug effects; Human Umbilical Vein Endothelial Cells - metabolism; Humans; Injections, Intramuscular; Ischemia - drug therapy; Ischemia - metabolism; Ischemia - physiopathology; Mice; Mice, Inbred C57BL; Muscle, Skeletal - blood supply; Neovascularization, Physiologic - drug effects; Oligopeptides - administration & dosage; Oligopeptides - metabolism; Oligopeptides - pharmacology; Protein Binding; Recovery of Function; Regional Blood Flow - drug effects; RNA Interference; Time Factors; Transfection; Vimentin - genetics; Vimentin - metabolism
• ISSN: 0026-2862; 1095-9319
• DOI: 10.1016/j.mvr.2011.07.006

We have previously identified several angiogenic peptides that bind cell surface proteins by screening a phage display peptide library on human umbilical endothelial cells exposed to hypoxic conditions. In this study we describe one of the selected peptides, SP. We found by protein precipitation of endothelial cell lysates that the 12 amino acid SP peptide binds cell surface vimentin. Surprisingly, vimentin was detected on the cell surface of about 30% of intact endothelial cells under both normoxic and hypoxic conditions, as was demonstrated by fluorocytometric analysis on viable cells. The assessment of SP in the induction of angiogenesis was established by a significant increase in endothelial cell proliferation and tube formation under hypoxic conditions and not under normoxic conditions. Cell proliferation and tube length increased two-fold in endothelial cells in the presence of 10ng/ml SP peptide when compared to controls. The specificity of SP binding to vimentin was demonstrated by SP inhibition of anti-vimentin binding and by the inhibition of tube formation in cells transfected with siRNA against vimentin. Local intramuscular administrations of the peptide SP to ischemic hind limbs using the mouse hind limb ischemia model, demonstrated that SP inoculated at 1 and 10μg, improved blood perfusion compared to inoculations with an irrelevant peptide or PBS. The recovery of blood perfusion correlated with the increase in the number of detectable capillaries in the ischemic limb. The development of novel peptides for the induction of pro-angiogenic activity may pave the way for new therapeutic strategies in the treatment of cardiovascular ischemic diseases. [Display omitted] ► Novel peptide of 12 amino acids binds to endothelial cell surface receptor identified as vimentin. ► Binding of the peptide to vimentin triggers endothelial cell tube formation under hypoxic conditions. ► Local administration of the peptide to mouse hind limb ischemia model improves blood perfusion and induced increase in capillary density.