title: Overexpression of matrix metalloproteinase-9 promotes intravascular thrombus formation in porcine coronary arteries in vivo.
abstract: OBJECTIVE
  Matrix metalloproteinases (MMPs) cause extracellular matrix degradation and may be involved in the rupture of atherosclerotic plaques by degrading fibrous cap, resulting in the intravascular thrombus formation. Here we examined whether local overexpression of MMP-9 alters the characteristics of arteriosclerotic vascular lesions and promotes thrombosis after balloon injury in porcine coronary arteries in vivo.
  
  
  RESULTS
  Balloon angioplasty was performed in the left coronary arteries followed by injection of adenovirus vector solution encoding either MMP-9 or beta-galactosidase (beta-gal) gene into the injured coronary arteries. Three weeks after the gene transfer, histological examination demonstrated that macroscopic intravascular thrombus formation was noted at the MMP-9-transfected site but not at the beta-gal-transfected site. Microscopic intramural thrombus area was significantly larger at the MMP-9-transfected site as compared to the beta-gal-transfected site. Co-transfection of tissue inhibitor of metalloproteinase-1 (TIMP-1) with MMP-9 prevented the intravascular thrombus formation in vivo. Western blot analysis revealed the reduced expression of intact tissue factor pathway inhibitor-1 and the increased tissue factor (TF) expression at the MMP-9-transfected sites.
  
  
  CONCLUSIONS
  These results provide the first in vivo evidence that overexpression of MMP-9 promotes intravascular thrombus formation after balloon injury due in part to the activation of TF-mediated coagulation cascade.
authors.affiliation: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Morishige
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shimokawa
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Eto
authors.forename: Toyokazu
authors.initials: T
authors.lastname: Uwatoku
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Abe
authors.forename: Katsuo
authors.initials: K
authors.lastname: Sueishi
authors.forename: Akira
authors.initials: A
authors.lastname: Takeshita
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D000818:Animals; D003324:Coronary Artery Disease / Q000150:complications / Q000628:therapy; D003328:Coronary Thrombosis / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D005822:Genetic Vectors; D008074:Lipoproteins / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013552:Swine; D013925:Thromboplastin / Q000378:metabolism; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000502:physiology; D014162:Transfection
chemical_list: D008074:Lipoproteins; D019715:Tissue Inhibitor of Metalloproteinase-1; C051928:lipoprotein-associated coagulation inhibitor; D013925:Thromboplastin; D020780:Matrix Metalloproteinase 9