title: Proprotein convertases regulate insulin-like growth factor 1-induced membrane-type 1 matrix metalloproteinase in VSMCs via endoproteolytic activation of the insulin-like growth factor-1 receptor.
abstract: The IGF-1 receptor (IGF-1R) and MT1-MMP are synthesized as larger precursor proproteins, which require endoproteolytic activation by the proprotein convertases (PCs) furin/PC5 to gain full biological activity. The aim of this study was to investigate the contribution of PCs to IGF-1R and/or MT1-MMP activation in vascular smooth muscle cells (VSMCs) as well as VSMC proliferation/migration, which are key elements in vascular remodeling. Furin and PC5 mRNAs and proteins were found in VSMCs. Inhibition of furin-like PCs with the specific pharmacological inhibitor dec-CMK inhibited IGF-1R endoproteolytic activation. Inhibition of IGF-1R maturation abrogated IGF-induced IGF-1R autophosphorylation, PI3-kinase and MAPK induction, as well as VSMC proliferation (p<0.05 vs. controls), whereas it had no effect of PDGF-stimulated signaling pathways or cell growth. Both, IGF-1 and PDGF-BB, induced MT1-MMP expression, but only IGF-1-mediated MT1-MMP induction was inhibited by dec-CMK. Induction of MMP-2 by IGF-1 was inhibited by the PI3-kinase inhibitor wortmannin, but not by the MEK-inhibitor PD98059. Dec-CMK inhibited VSMC chemotaxis comparable to the effects of the MMP-inhibitor GM6001 (both p<0.05 vs. controls), supporting that MMPs are involved. In conclusion, this study demonstrates that targeting furin-like PCs and thus inhibiting IGF-1R activation is a novel target to inhibit IGF-1-mediated signaling and cell functions, such as IGF-1-induced MT1-MMP/MMP-2 in VSMCs.
authors.affiliation: Department of Medicine/Cardiology, Deutsches Herzzentrum Berlin, Germany. stawowy@dhzb.de
authors.forename: Philipp
authors.initials: P
authors.lastname: Stawowy
authors.forename: Heike
authors.initials: H
authors.lastname: Kallisch
authors.forename: Adam
authors.initials: A
authors.lastname: Kilimnik
authors.forename: Christian
authors.initials: C
authors.lastname: Margeta
authors.forename: Nabil G
authors.initials: NG
authors.lastname: Seidah
authors.forename: Michel
authors.initials: M
authors.lastname: Chrétien
authors.forename: Eckart
authors.initials: E
authors.lastname: Fleck
authors.forename: Kristof
authors.initials: K
authors.lastname: Graf
mesh_terms: D000818:Animals; D000077214:Becaplermin; D002455:Cell Division; D002465:Cell Movement; D002478:Cells, Cultured; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D045683:Furin / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D045702:Proprotein Convertase 5 / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D020574:Proto-Oncogene Proteins c-sis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D004791:Enzyme Inhibitors; D010982:Platelet-Derived Growth Factor; D011498:Protein Precursors; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D007334:Insulin-Like Growth Factor I; D019869:Phosphatidylinositol 3-Kinases; D017526:Receptor, IGF Type 1; D020928:Mitogen-Activated Protein Kinases; D045702:Proprotein Convertase 5; D045683:Furin; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2