title: Bradykinin augments EGF-induced airway smooth muscle proliferation by activation of conventional protein kinase C isoenzymes.
abstract: This study aims to investigate the effects of bradykinin, alone and in combination with growth factors on proliferation of cultured bovine tracheal smooth muscle cells. Bradykinin did not induce mitogenic responses by itself, but concentration-dependently augmented growth factor-induced [3H]thymidine incorporation and cell proliferation. The bradykinin effect was mediated by bradykinin B2 receptors, and not dependent on cyclo-oxygenase. Bradykinin-induced synergism with epidermal growth factor (EGF) could be suppressed by the protein kinase C (PKC) inhibitors GF 109203X (Bisindolylmaleimide I; specific for conventional and novel PKCs) and Gö 6976 (12-(2-Cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrolo(3,4-c)-carbazole; specific for conventional PKCs). In addition, sole activation of PKC using Phorbol 12-myristate 13-acetate (PMA) was sufficient for a synergistic interaction with EGF. In contrast to bradykinin however, PMA was mitogenic by itself which was not at all affected by Gö 6976, but abolished by GF 109203X. Bradykinin transiently activated the p42/p44 MAP kinase pathway, whereas PMA-induced activation of p42/p44 mitogen activated protein (MAP) kinase was sustained. Neither the combination of bradykinin and EGF nor that of PMA and EGF induced synergistic activation of p42/p44 MAP kinase, however. These results show that bradykinin B2 receptor-stimulation augments growth factor-induced mitogenic responses of airway smooth muscle cells through activation of conventional PKC isozymes. In addition, the results show that PKC isozyme-specificity underlies stimulus-specific differences in mitogenic capacity for bradykinin and PMA.
authors.affiliation: Department of Molecular Pharmacology, University Centre for Pharmacy, University of Groningen, Deusinglaan 1, 9713 AV Groningen, The Netherlands. r.gosens@rug.nl
authors.forename: Reinoud
authors.initials: R
authors.lastname: Gosens
authors.forename: Mechteld M
authors.initials: MM
authors.lastname: Grootte Bromhaar
authors.forename: Harm
authors.initials: H
authors.lastname: Maarsingh
authors.forename: Anita
authors.initials: A
authors.lastname: ten Damme
authors.forename: Herman
authors.initials: H
authors.lastname: Meurs
authors.forename: Johan
authors.initials: J
authors.lastname: Zaagsma
authors.forename: S Adriaan
authors.initials: SA
authors.lastname: Nelemans
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002227:Carbazoles / Q000494:pharmacology; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D007211:Indoles / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D008301:Maleimides / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D043782:Receptor, Bradykinin B2 / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D014132:Trachea / Q000166:cytology; D014316:Tritium
chemical_list: D002227:Carbazoles; D004791:Enzyme Inhibitors; D007211:Indoles; D007527:Isoenzymes; D008301:Maleimides; D043782:Receptor, Bradykinin B2; D014316:Tritium; C081021:Go 6976; D004815:Epidermal Growth Factor; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C070515:bisindolylmaleimide I; D013755:Tetradecanoylphorbol Acetate; D001920:Bradykinin; D013936:Thymidine