title: Cartilage oligomeric matrix protein (thrombospondin-5) is expressed by human vascular smooth muscle cells.
abstract: Cartilage oligomeric matrix protein (COMP/thrombospondin [TSP]-5) belongs to the thrombospondin gene family and is an extracellular glycoprotein found predominantly in cartilage and tendon. To date, there is limited evidence of COMP/TSP-5 expression outside of the skeletal system. The aim of the present study was to investigate the expression of COMP/TSP-5 in cultured human vascular smooth muscle cells and human arteries. COMP/TSP-5 mRNA and protein expression was detected in cultured human vascular smooth muscle cells with both Northern blotting and immunoprecipitation. Serum, as well as transforming growth factor (TGF)beta1 and TGF-beta3, stimulated COMP/TSP-5 mRNA expression. COMP/TSP-5 was detected in normal as well as atherosclerotic and restenotic human arteries with immunohistochemistry. The majority of COMP/TSP-5 was expressed in close proximity to vascular smooth muscle cells. In vitro attachment assays demonstrated strong adhesion of smooth muscle cells to COMP/TSP-5-coated surfaces, with the majority of cells spreading and forming stress fibers. In addition, COMP/TSP-5 supported the migration of smooth muscle cells in vitro. The present study shows that COMP/TSP-5 is present in human arteries and may play a role in the adhesion and migration of vascular smooth muscle cells during vasculogenesis and in vascular disease settings such as atherosclerosis.
authors.affiliation: Department of Medicine III (Cardiology), University of Tübingen, Tübingen, Germany. reimer.riessen@uni-tuebingen.de
authors.forename: R
authors.initials: R
authors.lastname: Riessen
authors.forename: M
authors.initials: M
authors.lastname: Fenchel
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: D I
authors.initials: DI
authors.lastname: Axel
authors.forename: K R
authors.initials: KR
authors.lastname: Karsch
authors.forename: J
authors.initials: J
authors.lastname: Lawler
mesh_terms: D002356:Cartilage / Q000098:blood supply / Q000378:metabolism*; D064236:Cartilage Oligomeric Matrix Protein; D002465:Cell Movement; D002478:Cells, Cultured; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D008323:Mammary Arteries / Q000737:chemistry; D064235:Matrilin Proteins; D005810:Multigene Family; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D013194:Staining and Labeling; D019699:Thrombospondins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology
chemical_list: D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; D012333:RNA, Messenger; C577553:TSP5 protein, human; D019699:Thrombospondins