Activation of GRP78 on endothelial cell membranes by an ADAM15-derived peptide induces angiogenesis.
Impaired angiogenesis is one of the features of ischemic diseases. We have previously identified, by screening a phage display peptide library, a peptide that induces angiogenesis in endothelial cells under hypoxic conditions by binding the cell's membrane heat shock protein GRP78. Protein data base search identified 4 amino acids (HWRR) of that synthetic peptide present on the ADAM15 metalloprotease domain, a protein considered to be involved in neovascularization. Three peptides were synthesized according to the ADAM15 sequence placing HWRR at different positions. Peptide ADoPep1 exhibited significant angiogenic properties under hypoxic conditions as determined by cell proliferation, migration and tube formation. In a mouse hind limb ischemia model, a single injection of the peptide restored blood perfusion. The identified peptide was found to activate GRP78 on endothelial cell membrane and siRNA directed against the GRP78 mRNA interfered with induction of angiogenesis by the peptide. The peptide binding induced a decrease in heat shock protein GRP78 that is overexpressed under hypoxic conditions. The mechanism of peptide-induced angiogenic activity involves inhibition of apoptosis as well as increased Akt phosphorylation and ERK 1/2 activation. The peptide did not induce VEGF receptor-2 protein synthesis and phosphorylation, suggesting a VEGF-independent mechanism of angiogenesis.
Raiter
Annat
A
Felsenstein Medical Research Center, Tel-Aviv University School of Medicine, Rabin Medical Center, Beilinson Campus, Petach-Tikva, Israel.
Weiss
Chana
C
Bechor
Zafrir
Z
Ben-Dor
Itzik
I
Battler
Alexander
A
Kaplan
Boris
B
Hardy
Britta
B
D051722:ADAM Proteins / Q000737:chemistry / Q000502:physiology; D000818:Animals; D002478:Cells, Cultured; D000091342:Endoplasmic Reticulum Chaperone BiP; D042783:Endothelial Cells / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D007511:Ischemia / Q000188:drug therapy; D008565:Membrane Proteins / Q000737:chemistry / Q000502:physiology; D051379:Mice; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology*; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology
C572757:ADAM15 protein (286-297); D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; C552058:His-Trp-Arg-Arg; C000717248:Hspa5 protein, mouse; D008565:Membrane Proteins; D009842:Oligopeptides; D042461:Vascular Endothelial Growth Factor A; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048052:Mitogen-Activated Protein Kinase 3; D051722:ADAM Proteins; C098660:ADAM15 protein, human