Inhibition of von Willebrand factor-mediated platelet activation and thrombosis by the anti-von Willebrand factor A1-domain aptamer ARC1779.

Abstract

BACKGROUND:

von Willebrand factor (VWF) has a role in both hemostasis and thrombosis. Platelets adhere to damaged arteries by interactions between the VWF A1-domain and glycoprotein Ib receptors under conditions of high shear. This initial platelet binding event stimulates platelet activation, recruitment, and activation of the clotting cascade, promoting thrombus formation.

OBJECTIVE:

To characterize the inhibitory activity of a VWF inhibitory aptamer.

METHODS:

Using in vitro selection, aptamer stabilization, and conjugation to a 20-kDa poly(ethylene glycol), we generated a nuclease-resistant aptamer, ARC1779, that binds to the VWF A1-domain with high affinity (K(D) approximately 2 nM). The aptamer was assessed for inhibition of VWF-induced platelet aggregation. In vitro inhibition of platelet adhesion was assessed on collagen-coated slides and injured pig aortic segments. In vivo activity was assessed in a cynomolgus monkey carotid electrical injury thrombosis model.

RESULTS AND CONCLUSION:

ARC1779 inhibited botrocetin-induced platelet aggregation (IC90 approximately 300 nM) and shear force-induced platelet aggregation (IC95 approximately 400 nM). It reduced adhesion of platelets to collagen-coated matrices and formation of platelet thrombi on denuded porcine arteries. ARC1779 also inhibited the formation of occlusive thrombi in cynomolgus monkeys. We have discovered a novel anti-VWF aptamer that could have therapeutic use as an anti-VWF agent in the setting of VWF-mediated thrombosis.

• Authors: J L Diener, H A Daniel Lagassé, D Duerschmied, Y Merhi, J-F Tanguay, R Hutabarat, J Gilbert, D D Wagner, R Schaub
• Journal: Journal of thrombosis and haemostasis : JTH (J Thromb Haemost) Vol. 7 Issue 7 Pg. 1155-62 (Jul 2009) ISSN: 1538-7836 [Electronic] England
• PMID: 19422452 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• ARC 1779
• Aptamers, Nucleotide
• DNA Primers
• Platelet Aggregation Inhibitors
• von Willebrand Factor

Topics

• Animals
• Aptamers, Nucleotide (pharmacology)
• Arteries (injuries)
• Base Sequence
• DNA Primers
• Electric Stimulation
• Macaca fascicularis
• Nucleic Acid Conformation
• Platelet Activation (drug effects)
• Platelet Aggregation Inhibitors (pharmacology)
• Swine
• Thrombosis (prevention & control)
• von Willebrand Factor (antagonists & inhibitors, genetics)