Involvement of the TP receptor in TNF-α-induced endothelial tissue factor expression.
BACKGROUND
Thromboxane (TX) A2, prostaglandin endoperoxides and F2-isoprostanes exert their effects through a TX-prostanoid (TP) receptor, also expressed in endothelial cells. We investigated a role of the TP receptor in the endothelial expression of tissue factor (TF), a key trigger to thrombosis.


RESULTS
Human umbilical vein endothelial cells (HUVEC) exposed to the TP receptor agonist U46619 featured a concentration-dependent increase in TF surface exposure and procoagulant activity. HUVEC pre-incubation with the TP receptor antagonist S18886, followed by stimulation with either U46619 or tumor necrosis factor-α (TNF-α), attenuated TF surface exposure and activity compared with stimulated control. Aspirin or indomethacin, while inhibiting cyclooxygenase (COX)-1 and -2 activities, did not mimic this effect. Probing of underlying mechanisms by selective pharmacological and gene silencing experiments showed that S18886 reduced U46619- or TNF-α-induced TF expression inhibiting ROS production, NAD(P)H oxidase and PKC activation. In addition, S18886 also inhibited ERK activation in the presence of both U46619 and TNF-α alone, while inhibition of JNK activation only occurred in the presence of U46619.


CONCLUSIONS
The endothelial TP receptor contributes to TF surface exposure and activity induced not only by known TP receptor agonists, but also by TNF-α. Such findings expand the therapeutic potential of TP receptor inhibition.
Institute of Clinical Physiology, Consiglio Nazionale delle Ricerche (CNR), 56124 Pisa, Italy.
Serena
S
Del Turco
Institute of Clinical Physiology, Consiglio Nazionale delle Ricerche (CNR), 56124 Pisa, Italy.
Giuseppina
G
Basta
Institute of Clinical Physiology, Consiglio Nazionale delle Ricerche (CNR), 56124 Pisa, Italy.
Guido
G
Lazzerini
Institut de Recherches Internationales Servier, 92415 Courbevoie Cedex, France.
Laurent
L
Chancharme
Institut de Recherches Internationales Servier, 92415 Courbevoie Cedex, France.
Laurence
L
Lerond
Fondazione Toscana "G. Monasterio", 56124 Pisa, Italy; Institute of Cardiology and Center of Excellence on Aging, "G. d'Annunzio" University, 66013 Chieti, Italy. Electronic address: rdecater@unich.it.
Raffaele
R
De Caterina
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D002478:Cells, Cultured; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004727:Endothelium / Q000187:drug effects / Q000378:metabolism*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D009249:NADP / Q000378:metabolism; D009281:Naphthalenes / Q000494:pharmacology; D011422:Propionates / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D017482:Receptors, Thromboxane / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013925:Thromboplastin / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D009281:Naphthalenes; D011422:Propionates; D017382:Reactive Oxygen Species; D017482:Receptors, Thromboxane; D014409:Tumor Necrosis Factor-alpha; D009249:NADP; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D013925:Thromboplastin; C501362:terutroban; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011493:Protein Kinase C
Endothelial cells; Mitogen activated protein kinases; TP receptors; Thromboxane A(2); Tissue factor