Cyclooxygenase-2-derived prostacyclin regulates arterial thrombus formation by suppressing tissue factor in a sirtuin-1-dependent-manner

Silvia S. Barbieri, Patrizia Amadio, Sara Gianellini, Eva Tarantino, Elena Zacchi, Fabrizio Veglia, Louise R. Howe, Babette B. Weksler, Luciana Mussoni, Elena Tremoli

Research output: Contribution to journalArticlepeer-review


BACKGROUND-: Selective inhibitors of cyclooxygenase (COX)-2 increase the risk of myocardial infarction and thrombotic events, but the responsible mechanisms are not fully understood. METHODS AND RESULTS-: We found that ferric chloride-induced arterial thrombus formation was significantly greater in COX-2 knockout compared with wild-type mice. Cross-transfusion experiments excluded the likelihood that COX-2 knockout platelets, despite enhanced aggregation responses to collagen and thrombin, are responsible for increased arterial thrombus formation in COX-2 knockout mice. Importantly, we observed that COX-2 deletion decreased prostacyclin synthase and production and peroxisome proliferator-activated receptor-and sirtuin-1 (SIRT1) expression, with consequent increased upregulation of tissue factor (TF), the primary initiator of blood coagulation. Treatment of wild-type mice with a prostacyclin receptor antagonist or a peroxisome proliferator-activated receptor-δ antagonist, which predisposes to arterial thrombosis, decreased SIRT1 expression and increased TF activity. Conversely, exogenous prostacyclin or peroxisome proliferator-activated receptor-δ agonist completely reversed the thrombotic phenotype in COX-2 knockout mice, restoring normal SIRT1 levels and reducing TF activity. Furthermore, inhibition of SIRT1 increased TF expression and activity and promoted generation of occlusive thrombi in wild-type mice, whereas SIRT1 activation was sufficient to decrease abnormal TF activity and prothrombotic status in COX-2 knockout mice. CONCLUSIONS-: Modulation of SIRT1 and hence TF by prostacyclin/peroxisome proliferator-activated receptor-δ pathways not only represents a new mechanism in controlling arterial thrombus formation but also might be a useful target for therapeutic intervention in the atherothrombotic complications associated with COX-2 inhibitors.

Original languageEnglish
Pages (from-to)1373-1384
Number of pages12
Issue number11
Publication statusPublished - Sept 11 2012


  • blood coagulation
  • carotid arteries
  • prostacyclin
  • signal transduction
  • thrombosis

ASJC Scopus subject areas

  • Physiology (medical)
  • Cardiology and Cardiovascular Medicine


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