title: Interaction of clodronate with fibroblast growth factor 2 reduces FGF2-activity in endothelial cells.
abstract: Stabilization of fibroblast growth factors from heat denaturation and proteolytic digestion by bound heparin and heparan sulphate proteoglycans is known for more than 20 years. Furthermore, ATP-binding to FGF2 also leads to stabilization of this growth factor as discovered recently. The physiological importance of this protection is not yet clear but has become the focal point of interest. In this study we used the method of stabilizing FGF2 from proteolytic degradation to identify some bisphosphonates, namely clodronate and etidronate, which interact with FGF2. These two bisphoshonates protect FGF2 from tryptic digestion in vitro. The circular dichroism spectrum of FGF2 incubated with clodronate was significantly shifted compared to the spectrum of non-treated FGF2 indicating a conformational change of the protein after clodronate-binding. Additionally, clodronate and etidronate at low μM concentrations induce a concentration-dependent reduction of FGF2-induced cell proliferation of human umbilical vein endothelial cells. In contrast, proliferation of these cells after addition of clodronate and etidronate without FGF2 was not influenced by these bisphosphonates. Furthermore, the intracellular signaling via ERK1/2 and AKT was inhibited by clodronate and the tube formation, indicating the beginning process of angiogenesis, was reduced. Our results show for the first time that bisphosphonates I) interact with FGF2, II) reduce FGF2-activity and III) decrease the angiogenic potential of this growth factor.
authors.affiliation: Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Hittorfstr, 58-62, 48149 Münster, Germany. rosek@uni-muenster.de
authors.forename: K
authors.initials: K
authors.lastname: Rose
authors.forename: I E
authors.initials: IE
authors.lastname: Finger
authors.forename: K B
authors.initials: KB
authors.lastname: Ferenz
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004002:Clodronic Acid / Q000494:pharmacology*; D042783:Endothelial Cells / Q000187:drug effects*; D012968:Etidronic Acid / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D011487:Protein Conformation
chemical_list: D004002:Clodronic Acid; D016222:Fibroblast Growth Factor 2; D000255:Adenosine Triphosphate; D012968:Etidronic Acid