title: Dilazep, an antiplatelet agent, inhibits tissue factor expression in endothelial cells and monocytes.
abstract: Dilazep, an antiplatelet agent, is generally used as an antithrombotic drug in clinical practice. Dilazep is also known to exert cytoprotective and antioxidant effects on endothelial cells. However, its effect on the endothelial or monocyte procoagulant activity is unknown. In the current study, the effect of dilazep on the expression of tissue factor (TF) in human umbilical vein endothelial cells (HUVECs) after the stimulation with tumor necrosis factor-alpha (TNF), thrombin, or phorbol 12-myristate 13-acetate (PMA) was evaluated. We also evaluated the effect of dilazep on TNF (1,000 U/mL)-induced TF expression on monocytes. Dilazep inhibited TF activity induced on HUVECs by each stimulant, TNF (1000 U/mL), thrombin (25 nmol/L), or PMA (5 nmol/L) in a dose-dependent fashion (1 to 100 microg/mL). TF activity decreased to approximately 10% after treating with 100 microg/mL of dilazep. Dilazep also blocked the expression of TF antigen induced by each stimulant on the surface of HUVECs as determined by flow cytometric analysis. In addition, in HUVECs, it significantly decreased the expression of TF mRNA and the total TF antigen induced by thrombin or PMA, but not those induced by TNF, suggesting that dilazep blocks the TF expression induced by PMA or thrombin at a transcriptional level and that induced by TNF at a posttranscriptional level. Western blot analysis showed that dilazep reduces the accumulation of native TF but increases that in lower molecular weight TF derivatives. The adenosine receptor antagonist, 8-(p-sulfophenyl) theophylline, partially counteracted the anticoagulant activity of dilazep on HUVECs, thereby suggesting that the inhibitory effect of dilazep on TF expression in HUVECs depends, at least in part, on its adenosine potentiating activity. Dilazep also inhibited TNF-induced TF expression on monocytes in a dose-dependent fashion (0.1 to 100 microg/mL). In brief, the current study showed for the first time that dilazep, a commonly used antiplatelet drug, strongly inhibits the TF expression in HUVECs and monocytes. Dilazep may have a potent therapeutic value in patients with hypercoagulable state for its inhibitory property on the procoagulant activity of endothelial cells and monocytes.
authors.affiliation: Department of Molecular Pathobiology, Mie University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Deguchi
authors.forename: H
authors.initials: H
authors.lastname: Takeya
authors.forename: H
authors.initials: H
authors.lastname: Wada
authors.forename: E C
authors.initials: EC
authors.lastname: Gabazza
authors.forename: N
authors.initials: N
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Urano
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D004109:Dilazep / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D058906:Purinergic P1 Receptor Agonists; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D010975:Platelet Aggregation Inhibitors; D058906:Purinergic P1 Receptor Agonists; D014409:Tumor Necrosis Factor-alpha; C031433:8-(4-sulfophenyl)theophylline; D013925:Thromboplastin; D013806:Theophylline; D013917:Thrombin; D004109:Dilazep; D000241:Adenosine; D013755:Tetradecanoylphorbol Acetate