title: Activation of Cell Surface Bound 20S Proteasome Inhibits Vascular Cell Growth and Arteriogenesis.
abstract: Arteriogenesis is an inflammatory process associated with rapid cellular changes involving vascular resident endothelial progenitor cells (VR-EPCs). Extracellular cell surface bound 20S proteasome has been implicated to play an important role in inflammatory processes. In our search for antigens initially regulated during collateral growth mAb CTA 157-2 was generated against membrane fractions of growing collateral vessels. CTA 157-2 stained endothelium of growing collateral vessels and the cell surface of VR-EPCs. CTA 157-2 bound a protein complex (760 kDa) that was identified as 26 kDa α7 and 21 kDa β3 subunit of 20S proteasome in mass spectrometry. Furthermore we demonstrated specific staining of 20S proteasome after immunoprecipitation of VR-EPC membrane extract with CTA 157-2 sepharose beads. Functionally, CTA 157-2 enhanced concentration dependently AMC (7-amino-4-methylcoumarin) cleavage from LLVY (N-Succinyl-Leu-Leu-Val-Tyr) by recombinant 20S proteasome as well as proteasomal activity in VR-EPC extracts. Proliferation of VR-EPCs (BrdU incorporation) was reduced by CTA 157-2. Infusion of the antibody into the collateral circulation reduced number of collateral arteries, collateral proliferation, and collateral conductance in vivo. In conclusion our results indicate that extracellular cell surface bound 20S proteasome influences VR-EPC function in vitro and collateral growth in vivo.
authors.affiliation: Medical Department II, Experimental Angiology, University Hospital Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany ; Department of Cardiology, University Hospital Hamburg Eppendorf, Martinistraße 52, 20246 Hamburg, Germany ; Max-Planck Institute of Heart and Lung Research, Ludwigstraße 43, 61231 Bad Nauheim, Germany ; Cardiovascular Center Oberallgaeu-Kempten, Academic Teaching Hospital, University of Ulm, Im Stillen 2, 87509 Immenstadt, Germany.
authors.forename: Wulf D
authors.initials: WD
authors.lastname: Ito
authors.affiliation: Medical Department II, Experimental Angiology, University Hospital Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany ; Department of Cardiology, University Hospital Hamburg Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Natalie
authors.initials: N
authors.lastname: Lund
authors.affiliation: Medical Department II, Experimental Angiology, University Hospital Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany ; Department of Orthopedics, Hand Surgery Division, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China ; Department of Plastic Surgery and Hand Surgery, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675 Munich, Germany.
authors.forename: Ziyang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Clinical Chemistry, University Hospital Hamburg Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Buck
authors.affiliation: Department of Medicine, University Hospital Hamburg Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Lellek
authors.affiliation: Institute of Experimental Immunology and Hepatology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Horst
authors.affiliation: Department of Plastic Surgery and Hand Surgery, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675 Munich, Germany.
authors.forename: Hans-Günther
authors.initials: HG
authors.lastname: Machens
authors.affiliation: Medical Department II, Experimental Angiology, University Hospital Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany ; Department of Cardiology, German Heart Center Munich, Technical University of Munich, and Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Standard Munich Heart Alliance, Lazarettstraße 36, 80636 Munich, Germany.
authors.forename: Heribert
authors.initials: H
authors.lastname: Schunkert
authors.affiliation: Max-Planck Institute of Heart and Lung Research, Ludwigstraße 43, 61231 Bad Nauheim, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schaper
authors.affiliation: Department of Cardiology, University Hospital Hamburg Eppendorf, Martinistraße 52, 20246 Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Meinertz
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D001808:Blood Vessels / Q000254:growth & development / Q000276:immunology*; D049109:Cell Proliferation / Q000187:drug effects; D003097:Collateral Circulation / Q000276:immunology*; D042783:Endothelial Cells / Q000276:immunology; D066026:Endothelial Progenitor Cells / Q000276:immunology; D007249:Inflammation / Q000276:immunology* / Q000473:pathology; D046988:Proteasome Endopeptidase Complex / Q000276:immunology*; D051381:Rats
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D046988:Proteasome Endopeptidase Complex