BACKGROUND: Polyphosphate, a phosphate polymer released by activated platelets, has recently been described as a potent modulator of blood coagulation and fibrinolysis. In blood plasma, polyphosphate binds to and alters the biological functions of factor XII, fibrin(ogen), thrombin and factor VII activating protease. OBJECTIVES: The aim of the present study is to investigate whether polyphosphate also binds to von Willebrand factor (VWF) and alters some of its activities. METHODS/ RESULTS: When studying patients with type 1 von Willebrand disease (VWD) and their healthy relatives, we discovered a significant correlation between von Willebrand factor (VWF) and platelet polyphosphate levels. We have also found polyphosphate in preparations of VWF isolated from normal platelets and plasma. Surface plasmon resonance and electrophoretic mobility assays indicated that polyphosphate interacts with VWF in a dose- and time-dependent manner. Treatment of normal plasma with active exopolyphosphatase decreased the VWF ristocetin cofactor (VWF:RCo) activity, a functional measure of VWF binding to platelet glycoprotein receptor Ib. VWF collagen binding and multimerization were unaltered after polyphosphate depletion. Moreover, addition of polyphosphate increased the deficient VWF:RCo activity presented by plasma from patients with type 1 VWD. CONCLUSIONS: Our results reveal that a new role is played by polyphosphate in hemostasis by its interaction with VWF, and suggest that this polymer may be effective in the treatment of some types of VWD.
BACKGROUND:Polyphosphate, a phosphate polymer released by activated platelets, has recently been described as a potent modulator of blood coagulation and fibrinolysis. In blood plasma, polyphosphate binds to and alters the biological functions of factor XII, fibrin(ogen), thrombin and factor VII activating protease. OBJECTIVES: The aim of the present study is to investigate whether polyphosphate also binds to von Willebrand factor (VWF) and alters some of its activities. METHODS/ RESULTS: When studying patients with type 1 von Willebrand disease (VWD) and their healthy relatives, we discovered a significant correlation between von Willebrand factor (VWF) and platelet polyphosphate levels. We have also found polyphosphate in preparations of VWF isolated from normal platelets and plasma. Surface plasmon resonance and electrophoretic mobility assays indicated that polyphosphate interacts with VWF in a dose- and time-dependent manner. Treatment of normal plasma with active exopolyphosphatase decreased the VWF ristocetin cofactor (VWF:RCo) activity, a functional measure of VWF binding to platelet glycoprotein receptor Ib. VWF collagen binding and multimerization were unaltered after polyphosphate depletion. Moreover, addition of polyphosphate increased the deficient VWF:RCo activity presented by plasma from patients with type 1 VWD. CONCLUSIONS: Our results reveal that a new role is played by polyphosphate in hemostasis by its interaction with VWF, and suggest that this polymer may be effective in the treatment of some types of VWD.
Authors: Johan J F Verhoef; Arjan D Barendrecht; Katrin F Nickel; Kim Dijkxhoorn; Ellinor Kenne; Linda Labberton; Owen J T McCarty; Raymond Schiffelers; Harry F Heijnen; Antoni P Hendrickx; Huub Schellekens; Marcel H Fens; Steven de Maat; Thomas Renné; Coen Maas Journal: Blood Date: 2017-01-03 Impact factor: 22.113
Authors: Patricia H Alvarenga; Xueqing Xu; Fabiano Oliveira; Andrezza C Chagas; Clarissa R Nascimento; Ivo M B Francischetti; Maria A Juliano; Luiz Juliano; Julio Scharfstein; Jesus G Valenzuela; José M C Ribeiro; John F Andersen Journal: Arterioscler Thromb Vasc Biol Date: 2013-10-03 Impact factor: 8.311
Authors: Reiner K Mailer; Mikel Allende; Marco Heestermans; Michaela Schweizer; Carsten Deppermann; Maike Frye; Giordano Pula; Jacob Odeberg; Mathias Gelderblom; Stefan Rose-John; Albert Sickmann; Stefan Blankenberg; Tobias B Huber; Christian Kubisch; Coen Maas; Stepan Gambaryan; Dmitri Firsov; Evi X Stavrou; Lynn M Butler; Thomas Renné Journal: Blood Date: 2021-03-11 Impact factor: 22.113