Procoagulant platelet activation promotes venous thrombosis

Area of Science:

• Cardiovascular Biology
• Hemostasis and Thrombosis
• Platelet Physiology

Background:

• Platelet aggregation is a target for cardiovascular disease prevention, but current therapies are less effective for venous thromboembolism.
• Existing anticoagulation treatments for venous thromboembolism carry a high risk of bleeding complications.
• Novel therapeutic strategies are needed to target venous thrombosis effectively and safely.

Purpose of the Study:

• To investigate the role of platelet procoagulant activation (PA) in venous thrombosis.
• To explore targeting platelet PA as a therapeutic strategy for venous thromboembolism.
• To identify specific molecular pathways and potential drug targets involved in platelet PA.

Main Methods:

• Quantified procoagulant platelets in patients with deep vein thrombosis (DVT) and pulmonary embolism.
• Utilized mouse models of DVT to assess platelet PA in vivo.
• Generated mice with platelet-specific deficiencies in cyclophilin D and transmembrane protein 16F pathways.
• Administered methazolamide, a carbonic anhydrase inhibitor, to mice and evaluated its effect on platelet activity and thrombosis.
• Assessed hemostasis in mice following methazolamide treatment.

Main Results:

• Elevated levels of procoagulant platelets were observed in patients and mice with venous thromboembolism.
• Procoagulant activation of platelets was detected within thrombi in both murine and human samples.
• Mice deficient in key PA pathways (cyclophilin D, TMEM16F) showed resistance to venous thrombosis.
• Methazolamide reduced platelet procoagulant activity and alleviated venous thrombosis in mice.
• Methazolamide did not impair trauma-associated hemostasis.

Conclusions:

• Platelet procoagulant function is essential for venous thrombus formation.
• Targeting platelet procoagulant activity represents a promising therapeutic approach for venous thromboembolism.
• Methazolamide demonstrates potential as a novel agent for preventing venous thromboembolism by inhibiting platelet PA.
• This study identifies new pharmacologic strategies for managing venous thromboembolism with a potentially improved safety profile.