title: Molecular Mechanisms Mediating Antiangiogenic Action of the Urokinase Receptor-Derived Peptide UPARANT in Human Retinal Endothelial Cells.
abstract: OBJECTIVE
  To investigate the molecular mechanisms of the antiangiogenic activity of UPARANT, an antagonist of the urokinase-type plasminogen activator receptor (uPAR), on primary human retinal endothelial cells (HREC) as a model of in vitro angiogenesis.
  
  
  METHODS
  The antiangiogenic activity of UPARANT was evaluated on endothelial cell migration, invasion, and tube formation. Human REC were further analyzed for viability, transendothelial electrical resistance (TEER), and tight junction (TJ) expression at the protein and mRNA levels. Vascular endothelial growth factor-related signaling molecules were also analyzed by Western and northern blots.
  
  
  RESULTS
  UPARANT inhibited in a dose-dependent fashion HREC motility, invasion, and tube formation stimulated by VEGF-A, in a range of doses (1-100 nM) that had no effect on cell viability and proliferation. UPARANT also prevented the loss of permeability induced by VEGF-A, restoring normal TEER values and TJ protein expression. At the molecular level, UPARANT inhibited VEGFR-2 and STAT3 phosphorylation, thus decreasing VEGF and hypoxia-inducible factor 1-alpha expression, finally resulting in decreased activation of MEK/ERK, JNK, p38, and AKT signaling proteins.
  
  
  CONCLUSIONS
  These findings indicate that UPARANT exerts its antiangiogenic effects through the inhibition of the downstream signaling activated by angiogenic factors such as VEGF-A.
authors: Bioos Italia Srl, Catania, Italy.
authors: Carla
authors: C
authors: Motta
authors: Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.
authors: Gabriella
authors: G
authors: Lupo
authors: Sooft Italia Spa, Roma, Italy.
authors: Dario
authors: D
authors: Rusciano
authors: Sooft Italia Spa, Roma, Italy.
authors: Melania
authors: M
authors: Olivieri
authors: Department of Chemical Science, University of Naples "Federico II" via Cintia, Italy.
authors: Liliana
authors: L
authors: Lista
authors: Department of Experimental Medicine, Second University of Naples, Napoli, Italy.
authors: Mario
authors: M
authors: De Rosa
authors: Department of Chemical Science, University of Naples "Federico II" via Cintia, Italy.
authors: Vincenzo
authors: V
authors: Pavone
authors: Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.
authors: Carmelina Daniela
authors: CD
authors: Anfuso
mesh_terms: D015153:Blotting, Western; D002452:Cell Count; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D037241:Mannose-Binding Lectins / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012160:Retina / Q000378:metabolism / Q000473:pathology*; D015861:Retinal Neovascularization / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: C404106:MRC2 protein, human; D037241:Mannose-Binding Lectins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D040301:Vascular Endothelial Growth Factor Receptor-2