title: Induction of intracellular signalling in human endothelial cells by the hyaluronan-binding protease involves two distinct pathways.
abstract: Recently a novel plasma serine protease with high affinity to hyaluronic acid and glycosaminoglycans, such as heparin and heparan sulfate, has been described and termed hyaluronan-binding protease (HABP). HABP cleaves kininogen in vitro, releasing the vasoactive peptide bradykinin, and activates plasminogen activators, suggesting a vascular cell-directed physiological function of this novel plasma protease. Here we show that HABP stimulates human umbilical vein endothelial cells (HUVECs) by activating two distinct cell-surface receptors. On the one hand, HABP releases bradykinin from cell surface-bound or soluble kininogen and triggers a bradykinin B2-receptor-dependent mobilisation of intracellular Ca2+. On the other hand, HABP activates the p44/42-dependent MAPK (ERK1/2) signalling cascade independent of the B2-receptor, but involving the fibroblast growth factor receptor-1 and basic fibroblast growth factor. This signalling pathway leads to phosphorylation of the kinases Raf, MEK1/2 and ERK1/2. The extracellular activity of HABP also affects the gene expression level through phosphorylation of two transcription factors, the cAMP-responsive element binding protein CREB and the proto-oncogene c-Myc. Our results indicate a proangiogenic potential of HABP, which, in combination with a profibrinolytic activity, directs the physiological function of this plasma protease to processes in which clot lysis, cell motility and neovascularisation are pivotal processes, e.g., in wound healing, tissue repair and tumour progression.
authors.affiliation: Department of Haematology and Transfusion Medicine, Paul-Ehrlich-Institute, Federal Agency for Sera and Vaccines, D-63225 Langen, Germany.
authors.forename: Julia Anne
authors.initials: JA
authors.lastname: Kress
authors.forename: Rainer
authors.initials: R
authors.lastname: Seitz
authors.forename: Johannes
authors.initials: J
authors.lastname: Dodt
authors.forename: Michael
authors.initials: M
authors.lastname: Etscheid
mesh_terms: D001920:Bradykinin / Q000494:pharmacology; D002118:Calcium / Q000032:analysis / Q000502:physiology; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D043782:Receptor, Bradykinin B2 / Q000187:drug effects / Q000378:metabolism; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000378:metabolism; D012697:Serine Endopeptidases / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc; D043782:Receptor, Bradykinin B2; D051496:Receptor, Fibroblast Growth Factor, Type 1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D012697:Serine Endopeptidases; C492786:hyaluronan-binding protease, human; D001920:Bradykinin; D002118:Calcium