title: Statin prevents tissue factor expression in human endothelial cells: role of Rho/Rho-kinase and Akt pathways.
abstract: BACKGROUND
  Tissue factor plays a pivotal role in thrombus formation in acute coronary syndromes. However, the regulatory mechanisms underlying tissue factor expression are poorly understood. Statins are effective in patients with acute coronary syndromes. Hence, the aim of this study was to clarify in human endothelial cells the signaling pathways of thrombin-induced tissue factor expression and potential inhibitory effects of statins.
  
  
  RESULTS
  In human aortic endothelial cells, simvastatin prevented tissue factor induction by thrombin (4 U/mL) in a concentration-dependent manner. The increase in tissue factor activity on the cell surface was also blocked by simvastatin. Simvastatin also prevented the upregulation of tissue factor expression and activity in human aortic smooth muscle cells. Mevalonate (100 micromol/L) reversed the inhibitory effect of simvastatin on tissue factor expression. Thrombin induced rapid activation of Rho A and p38 MAP kinase. The Rho-kinase inhibitor Y-27632 and the p38 MAP kinase inhibitor SB203580 prevented tissue factor induction. Akt was dephosphorylated by thrombin; the phosphoinositol 3-kinase inhibitor wortmannin enhanced its dephosphorylation as well as thrombin-induced tissue factor expression. Simvastatin prevented thrombin-induced Rho A activation but not p38 MAP kinase activation. Akt dephosphorylation by thrombin was blocked by both simvastatin and Y-27632.
  
  
  CONCLUSIONS
  Endothelial tissue factor induction by thrombin is regulated by Rho/Rho-kinase, Akt, and p38 MAP kinase. Simvastatin prevents its induction through inhibition of Rho/Rho-kinase and activation of Akt. These findings provide new insights into the action of statins in acute coronary syndromes.
authors.affiliation: Division of Cardiology, CardioVascular Center, University Hospital and University of Zurich, Zurich, Switzerland.
authors.forename: Masato
authors.initials: M
authors.lastname: Eto
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kozai
authors.forename: Francesco
authors.initials: F
authors.lastname: Cosentino
authors.forename: Hana
authors.initials: H
authors.lastname: Joch
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Lüscher
mesh_terms: D001011:Aorta / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction / Q000187:drug effects; D019821:Simvastatin / Q000494:pharmacology*; D013917:Thrombin / Q000037:antagonists & inhibitors; D013925:Thromboplastin / Q000378:metabolism*; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D011518:Proto-Oncogene Proteins; D013925:Thromboplastin; D019821:Simvastatin; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D054460:rho-Associated Kinases; D020928:Mitogen-Activated Protein Kinases; D013917:Thrombin; D020742:rhoA GTP-Binding Protein