A murine model to characterize the antithrombotic effect of molecules targeting human von Willebrand factor

Mutations in the A3 domain of Von Willebrand factor inducing combined qualitative and quantitative defects in the protein

“…Indeed, we have previously shown that a collagen-binding defect prevents vessel occlusion but not initial thrombus formation in the ferric chloride-induced thrombosis model. 18,21 The second mutation, p.P1824H, 15 leads to a slightly different picture. Although low antigen levels are also observed with this mutant, it appears from our expression studies that this is due to intracellular retention and that cotransfection does not correct the defect, again suggesting a dominant negative effect of the mutant protein.…”

“…6 Both mutations were also introduced in a synthetic VWF complementary DNA (cDNA) encoding a chimeric human VWF protein in which the A1 domain was of murine origin (huVWFmuA1). 18 This chimeric construct is cloned into the pLIVE vector (Mirus Bio LLC, Madison, WI). All mutations were verified by DNA sequencing.…”

Exploiting the kinetic interplay between GPIbα–VWF binding interfaces to regulate hemostasis and thrombosis

“…This is consistent with the previous observation that human VWF cannot support these processes in mice unless it contains the murine A1 domain. 38 In the presence of human platelets, however, VWF HA1 mice formed large and often occlusive thrombi in laserinjured arterioles ( Figure 5D). Moreover, murine aIIbb3, or for that matter murine platelets, were not essential for this process as VWF HA1 animals lacking aΙIb or injected with rabbit serum that depletes mouse platelets 39 were still capable of supporting human platelet-mediated thrombus formation ( Figure 5D and supplemental Figure 5).…”

On the Versatility of Von Willebrand Factor

“…In contrast, this mutant shows a strongly delayed occlusion time in a ferric chloride-induced model of vascular injury, suggesting that blocking VWF-collagen interactions could be a potential therapeutic approach in the treatment of arterial thrombosis 100. This possibility has been explored in animal models for thrombosis, revealing that antibodies blocking VWF-collagen interactions are efficient in reducing the thrombotic tendency 101,102. Many in vitro studies revealed that VWF-collagen interactions are needed for the recruitment of platelets particularly under conditions of high shear rates (for reviews see Sixma et al 103 and Nuyttens et al 104).…”