Altered thrombus formation in von Willebrand factor-deficient mice expressing von Willebrand factor variants with defective binding to collagen or GPIIbIIIa.
The role of von Willebrand factor (VWF) in thrombosis involves its binding to a number of ligands. To investigate the relative importance of these particular interactions in the thrombosis process, we have introduced mutations into murine VWF (mVWF) cDNA inhibiting VWF binding to glycoprotein (Gp) Ib, GPIIbIIIa, or to fibrillar collagen. These VWF mutants were expressed in VWF-deficient mice (VWF(-/-)) by using an hydrodynamic injection approach, and the mice were studied in the ferric chloride-induced injury model. Expression of the collagen and the GPIIbIIIa VWF-binding mutants in VWF(-/-) mice resulted in delayed thrombus growth and significantly increased vessel occlusion times compared with mice expressing wild-type (WT) mVWF (30 +/- 3 minutes and 38 +/- 4 minutes for the collagen and GPIIbIIIa mutants, respectively, vs 19 +/- 3 minutes for WT mVWF). Interestingly, these mutants were able to correct bleeding time as efficiently as WT mVWF. In contrast, VWF(-/-) mice expressing the GPIb binding mutant failed to restore thrombus formation and were bleeding for as long as they were observed, confirming the critical importance of the VWF-GPIb interaction. Our observations suggest that targeting the VWF-collagen or VWF-GPIIbIIIa interactions could be an interesting alternative for new antithrombotic strategies.
Marx
Isabelle
I
Inserm U770 and Universite Paris-Sud, Le Kremlin-Bicêtre, France.
Christophe
Olivier D
OD
Lenting
Peter J
PJ
Rupin
Alain
A
Vallez
Marie-Odile
MO
Verbeuren
Tony J
TJ
Denis
Cécile V
CV
D000818:Animals; D003094:Collagen / Q000378:metabolism*; D014644:Genetic Variation; D006470:Hemorrhage / Q000209:etiology; D051379:Mice; D018345:Mice, Knockout; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000378:metabolism; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism*; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics / Q000502:physiology; D013927:Thrombosis / Q000209:etiology*; D014841:von Willebrand Factor / Q000235:genetics* / Q000378:metabolism
D050505:Mutant Proteins; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019038:Platelet Glycoprotein GPIb-IX Complex; D014841:von Willebrand Factor; D003094:Collagen