title: Paclitaxel enhances thrombin-induced endothelial tissue factor expression via c-Jun terminal NH2 kinase activation.
abstract: Paclitaxel is used on drug-eluting stents because it inhibits proliferation of vascular cells. Stent thrombosis remains a concern with this compound, particularly with higher dosages. This study investigates the effect of paclitaxel on tissue factor (TF) expression in human endothelial cells. Paclitaxel enhanced thrombin-induced endothelial TF protein expression in a concentration- and time-dependent manner. A concentration of 10(-5) mol/L elicited a 2.1-fold increase in TF protein and a 1.6-fold increase in TF surface activity. The effect was similar after a 1 hour as compared with a 25-hour pretreatment period. Real-time polymerase chain reaction revealed that paclitaxel increased thrombin-induced TF mRNA expression. Paclitaxel potently activated c-Jun terminal NH2 kinase (JNK) as compared with thrombin alone, whereas the thrombin-mediated phosphorylation of p38 and extracellular signal-regulated kinase remained unaffected. Similar to paclitaxel, docetaxel enhanced both TF expression and JNK activation as compared with thrombin alone. The JNK inhibitor SP600125 reduced thrombin-induced TF expression by 35%. Moreover, SP600125 blunted the effect of paclitaxel and docetaxel on thrombin-induced TF expression. Paclitaxel increases endothelial TF expression via its stabilizing effect on microtubules and selective activation of JNK. This observation provides novel insights into the pathogenesis of thrombus formation after paclitaxel-eluting stent deployment and may have an impact on drug-eluting stent design.
authors.affiliation: Cardiovascular Research, Physiology Institute, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Stähli
authors.forename: Giovanni G
authors.initials: GG
authors.lastname: Camici
authors.forename: Jan
authors.initials: J
authors.lastname: Steffel
authors.forename: Alexander
authors.initials: A
authors.lastname: Akhmedov
authors.forename: Kushiar
authors.initials: K
authors.lastname: Shojaati
authors.forename: Michelle
authors.initials: M
authors.lastname: Graber
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Lüscher
authors.forename: Felix C
authors.initials: FC
authors.lastname: Tanner
mesh_terms: D001011:Aorta / Q000166:cytology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology*; D015607:Stents / Q000009:adverse effects; D013917:Thrombin / Q000494:pharmacology*; D013925:Thromboplastin / Q000235:genetics; D013927:Thrombosis / Q000209:etiology
chemical_list: D013925:Thromboplastin; D048031:JNK Mitogen-Activated Protein Kinases; D013917:Thrombin; D017239:Paclitaxel