title: Characterization of heparin affin regulatory peptide signaling in human endothelial cells.
abstract: Heparin affin regulatory peptide (HARP) is an 18-kDa secreted growth factor that has a high affinity for heparin and a potent role on tumor growth and angiogenesis. We have previously reported that HARP is mitogenic for different types of endothelial cells and also affects cell migration and differentiation (12). In this study we examined the signaling pathways involved in the migration and tube formation on matrigel of human umbilical vein endothelial cells (HUVEC) induced by HARP. We report for the first time that receptor-type protein-tyrosine phosphatase beta/zeta (RPTPbeta/zeta), which is a receptor for HARP in neuronal cell types, is also expressed in HUVEC. We also document that HARP signaling through RPTPbeta/zeta leads to activation of Src kinase, focal adhesion kinase, phosphatidylinositol 3-kinase, and Erk1/2. Sodium orthovanadate, chondroitin sulfate-C, PP1, wortmannin, LY294002, and U0126 inhibit HARP-mediated signaling and HUVEC migration and tube formation. In addition, RPTPbeta/zeta suppression using small interfering RNA technology interrupts intracellular signals and HUVEC migration and tube formation induced by HARP. These results establish the role of RPTPbeta/zeta as a receptor of HARP in HUVEC and elucidate the HARP signaling pathway in endothelial cells.
authors.affiliation: Laboratory of Molecular Pharmacology, Department of Pharmacy, University of Patras, 26504 Patras, Greece.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Polykratis
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Katsoris
authors.forename: José
authors.initials: J
authors.lastname: Courty
authors.forename: Evangelia
authors.initials: E
authors.lastname: Papadimitriou
mesh_terms: D015153:Blotting, Western; D000081247:CSK Tyrosine-Protein Kinase; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D002465:Cell Movement; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D016207:Cytokines / Q000737:chemistry* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D047468:Immunoprecipitation; D007797:Laminin / Q000494:pharmacology; D009389:Neovascularization, Pathologic; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011509:Proteoglycans / Q000494:pharmacology; D012313:RNA / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors; D019061:src-Family Kinases
chemical_list: D000081247:CSK Tyrosine-Protein Kinase; D002352:Carrier Proteins; D003094:Collagen; D016207:Cytokines; D004338:Drug Combinations; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D007797:Laminin; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; D011509:Proteoglycans; D012313:RNA; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D019061:src-Family Kinases; C059485:matrigel; C066845:pleiotrophin; C496050:PTK2 protein, human; C000631346:CSK protein, human