title: The role of fibrinolytic genes and proteins in the development of allograft vascular disease.
abstract: BACKGROUND
  We have previously shown that lack of plasminogen activator inhibitor-1 (PAI-1) expression in donor tissue greatly increases intimal proliferation (IP) after allogeneic transplantation. We sought to determine the relative role of PAI-1 and other fibrinolytic proteins in the development of IP.
  
  
  METHODS
  We used an abdominal aortic transplant model in mice to investigate IP in 3 groups of 6 recipients. In the isograft group, CBA/J strain mice were donors and recipients, donors for allograft group were C57BL/6J mice, and for the allograft/knockout group, C57BL/6J PAI-1 knockout mice. All groups received weekly injections of anti-CD8/CD4 monoclonal antibodies. IP was calculated at 50 days, and sections were analyzed for fibrinolytic proteins, messenger RNA (mRNA) and PAI-1 activity using immunohistochemistry (IHC), in situ hybridization (ISH), reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analysis.
  
  
  RESULTS
  Significantly more IP developed in the allograft/knockout group vs the isograft (p < 0.001) and the allograft groups (p = 0.003). There was marked intimal expression of tissue plasminogen activator (tPA), urokinase PA (uPA), and uPA receptor (uPAR) proteins and mRNA in the allograft and allograft/knockout groups vs the isograft group. Allografts also showed significant intimal staining for PAI-1 protein and mRNA. RT-PCR demonstrated a stepwise increase in profibrinolytic protein mRNA from isograft to allograft to allograft/knockout groups, particularly uPA (p = 0.02) and uPAR (p = 0.016). Western blot data showed complementary findings. PAI-1 activity was persistently present in isograft and allograft animals, only. Intimas in allograft and allograft/knockout groups were primarily smooth muscle cells.
  
  
  CONCLUSIONS
  PAI-1 reduces IP by limiting smooth muscle cell activity, with little change in matrix composition likely by modulating profibrinolytic protein expression.
authors.affiliation: Division of Cardiovascular Medicine, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA. rbenza@wpahs.org
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Benza
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Passineau
authors.forename: Peter G
authors.initials: PG
authors.lastname: Anderson
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Barchue
authors.forename: James F
authors.initials: JF
authors.lastname: George
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000637:transplantation*; D049109:Cell Proliferation; D003324:Coronary Artery Disease / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D005342:Fibrinolysis / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000473:pathology / Q000503:physiopathology; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator / Q000235:genetics / Q000502:physiology*; D010959:Tissue Plasminogen Activator / Q000235:genetics / Q000502:physiology*; D014184:Transplantation, Homologous; D017539:Tunica Intima / Q000473:pathology / Q000503:physiopathology; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000502:physiology*
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D055293:Receptors, Urokinase Plasminogen Activator; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator