Type I von Willebrand disease, subtype ‘platelet low’: decreased platelet adhesion can be explained by low synthesis of von Willebrand factor in endothelial cells

We describe glycoprotein (GP) Ib as a mediator of adhesion to fibronectin, specifically in flow. A monoclonal antibody (MoAb) directed to the von Willebrand factor (vWF)-binding site on this receptor or the absence of this receptor on the platelet membrane, in the case of a patient with the Bernard-Soulier syndrome, reduced platelet coverage to fibronectin to approximately 30% of the control value. A MoAb directed to the GP Ib-binding site on vWF showed a similar effect. With washed platelets in the absence of plasma vWF, the inhibitory effect of the anti-GP Ib antibody was the same as with whole blood. No inhibition with the anti-GP Ib antibody was observed when we used blood from patients with severe von Willebrand disease (vWD) or from a patient with vWD type I (platelet low). Addition of vWF to vWD blood resulted in restoration of adhesion. Immunoelectron microscopy on platelets adhering to fibronectin showed that GP Ib was homogeneously distributed over the entire surface of the platelet. vWF was present at the central zone and the edges of the platelet and at the basal interface between the platelet and the fibronectin surface. No direct binding of vWF to fibronectin could be demonstrated. These data indicate that GP Ib-mediated adhesion to fibronectin fully depends on vWF and that normal levels of plasma or platelet vWF are sufficient for optimal adhesion to fibronectin. The data suggest that the presence of platelets during perfusion is a prerequisite for vWF to support platelet adhesion to fibronectin.

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Molecular studies of von Willebrand disease: reduced von Willebrand factor biosynthesis, storage, and release in endothelial cells derived from patients with type I von Willebrand disease [published erratum appears in Blood 1990 Nov 1;76(9):1901]

Blood ◽

10.1182/blood.v75.7.1466.1466 ◽

1990 ◽

Vol 75 (7) ◽

pp. 1466-1472 ◽

Cited By ~ 10

Author(s):

BM Ewenstein ◽

A Inbal ◽

JS Pober ◽

RI Handin

Keyword(s):

Endothelial Cells ◽

Von Willebrand Factor ◽

Messenger Rna ◽

Umbilical Vein ◽

Von Willebrand Disease ◽

Type I ◽

Molecular Defects ◽

Umbilical Vein Endothelial Cells ◽

Von Willebrand ◽

Willebrand Factor

Abstract Endothelial cells were cultured from the umbilical veins of two neonates with type I von Willebrand disease (vWD) and compared with cells cultured in parallel from normal control umbilical veins. In both cases, cultured vWD endothelial cells contained less messenger RNA (mRNA) encoding von Willebrand factor (vWF), and constitutively secreted two- to fourfold less vWF protein than their matched controls. Regulated secretion of stored vWF induced by thrombin or phorbol-12- myristate-13-acetate (PMA) was also diminished in vWD cells. Both the mRNA and protein produced by each of these type I vWD cells appeared to be of normal size. However, despite the diminished size of the vWF storage pool, electron microscopy of endothelial cells in situ showed normal appearing vWF storage organelles (Weibel-Palade bodies). These studies show that cultured umbilical vein endothelial cells can be used to explore the molecular defects in type I and perhaps other forms of vWD, and suggest that at least some forms of type I vWD are caused by diminished mRNA transcription or subsequent translation due to a defective vWF allele.

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von Willebrand factor synthesized by endothelial cells from a patient with type IIB von Willebrand disease supports platelet adhesion normally but has an increased affinity for platelets.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.86.10.3793 ◽

1989 ◽

Vol 86 (10) ◽

pp. 3793-3797 ◽

Cited By ~ 25

Author(s):

P. G. de Groot ◽

A. B. Federici ◽

H. C. de Boer ◽

P. d'Alessio ◽

P. M. Mannucci ◽

...

Keyword(s):

Endothelial Cells ◽

Von Willebrand Factor ◽

Platelet Adhesion ◽

Von Willebrand Disease ◽

Von Willebrand ◽

Willebrand Factor

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Molecular studies of von Willebrand disease: reduced von Willebrand factor biosynthesis, storage, and release in endothelial cells derived from patients with type I von Willebrand disease [published erratum appears in Blood 1990 Nov 1;76(9):1901]

Blood ◽

10.1182/blood.v75.7.1466.bloodjournal7571466 ◽

1990 ◽

Vol 75 (7) ◽

pp. 1466-1472

Author(s):

BM Ewenstein ◽

A Inbal ◽

JS Pober ◽

RI Handin

Keyword(s):

Endothelial Cells ◽

Von Willebrand Factor ◽

Messenger Rna ◽

Umbilical Vein ◽

Von Willebrand Disease ◽

Type I ◽

Molecular Defects ◽

Umbilical Vein Endothelial Cells ◽

Von Willebrand ◽

Willebrand Factor

Endothelial cells were cultured from the umbilical veins of two neonates with type I von Willebrand disease (vWD) and compared with cells cultured in parallel from normal control umbilical veins. In both cases, cultured vWD endothelial cells contained less messenger RNA (mRNA) encoding von Willebrand factor (vWF), and constitutively secreted two- to fourfold less vWF protein than their matched controls. Regulated secretion of stored vWF induced by thrombin or phorbol-12- myristate-13-acetate (PMA) was also diminished in vWD cells. Both the mRNA and protein produced by each of these type I vWD cells appeared to be of normal size. However, despite the diminished size of the vWF storage pool, electron microscopy of endothelial cells in situ showed normal appearing vWF storage organelles (Weibel-Palade bodies). These studies show that cultured umbilical vein endothelial cells can be used to explore the molecular defects in type I and perhaps other forms of vWD, and suggest that at least some forms of type I vWD are caused by diminished mRNA transcription or subsequent translation due to a defective vWF allele.

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Interventional Thermal Injury of the Arterial Wall: Unfolding of von Willebrand Factor and Its Increased Binding to Collagen after 55° C Heating

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650307 ◽

1996 ◽

Vol 75 (03) ◽

pp. 515-519 ◽

Cited By ~ 7

Author(s):

Mark J Post ◽

Anke N de Graaf-Bos ◽

George Posthuma ◽

Philip G de Groot ◽

Jan J Sixma ◽

...

Keyword(s):

Von Willebrand Factor ◽

Conformational Changes ◽

Arterial Wall ◽

Platelet Adhesion ◽

Type I ◽

Temperature Dependent ◽

Collagen Types ◽

Electron Microscopic ◽

Von Willebrand ◽

Willebrand Factor

Summary Purpose. Thermal angioplasty alters the thrombogenicity of the arterial wall. In previous studies, platelet adhesion was found to increase after heating human subendothelium to 55° C and decrease after heating to 90° C. In the present electron microscopic study, the mechanism of this temperature-dependent platelet adhesion to the heated arterial wall is elucidated by investigating temperature-dependent conformational changes of von Willebrand factor (vWF) and collagen types I and III and the binding of vWF to heated collagen. Methods. Purified vWF and/or collagen was applied to electron microscopic grids and heated by floating on a salt-solution of 37° C, 55° C or 90° C for 15 s. After incubation with a polyclonal antibody against vWF and incubation with protein A/gold, the grids were examined by electron microscopy. Results. At 37° C, vWF was coiled. At 55° C, vWF unfolded, whereas heating at 90° C caused a reduction in antigenicity. Collagen fibers heated to 37° C were 60.3 ± 3.1 nm wide. Heating to 55° C resulted in the unwinding of the fibers, increasing the width to 87.5 ± 8.2 nm (p < 0.01). Heating to 90° C resulted in denatured fibers with an enlarged width of 85.1 ± 6.1 nm (p < 0.05). Heating of collagen to 55° C resulted in an increased vWF binding as compared to collagen heated to 37° C or to 90° C. Incubation of collagen with vWF, prior to heating, resulted in a vWF binding after heating to 55° C that was similar to the 37° C binding and a decreased binding after 90° C. Conclusions. After 55° C heating, the von Willebrand factor molecule unfolds and collagen types I and III exhibit an increased adhesiveness for von Willebrand factor. Heating to 90° C denatures von Willebrand factor and collagen. The conformation changes of von Willebrand factor and its altered binding to collagen type I and III may explain the increased and decreased platelet adhesion to subendothelium after 55° C and 90° C heating, respectively.

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The Genetic Defect of Type I von Willebrand Disease “Vicenza” Is Linked to the von Willebrand Factor Gene

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651575 ◽

1993 ◽

Vol 69 (02) ◽

pp. 173-176 ◽

Cited By ~ 5

Author(s):

Anna M Randi ◽

Elisabetta Sacchi ◽

Gian Carlo Castaman ◽

Francesco Rodeghiero ◽

Pier Mannuccio Mannucci

Keyword(s):

Von Willebrand Factor ◽

Autosomal Dominant ◽

Genetic Defect ◽

Von Willebrand Disease ◽

Type I ◽

Bleeding Tendency ◽

Factor Gene ◽

Low Levels ◽

Von Willebrand ◽

Willebrand Factor

SummaryType I von Willebrand disease (vWD) Vicenza is a rare variant with autosomal dominant transmission, characterized by the presence of supranormal von Willebrand factor (vWF) multimers in plasma, similar to those normally found in endothelial cells and megakaryocytes. The patients have very low levels of plasma vWF contrasting with a mild bleeding tendency. The pathophysiology of this subtype is still unknown. The presence of supranormal multimers in the patients’ plasma could be due to a mutation in the vWF molecule which affects post-translational processing, or to a defect in the cells’ processing machinery, independent of the vWF molecule. In order to determne if type I vWD Vicenza is linked to the vWF gene, we studied six polymorphic systems identified within the vWF gene in two apparently unrelated families with type I vWD Vicenza. The results of this study indicate a linkage between vWF gene and the type I vWD Vicenza trait. This strongly suggests that type I vWD Vicenza is due to a mutation in one of the vWF alleles, which results in an abnormal vWF molecule that is processed to a lesser extent than normal vWF.

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The genetic defect of type i von willebrand disease “vicenza” is linked to the von willebrand factor gene

Thrombosis Research ◽

10.1016/0049-3848(93)90443-r ◽

1993 ◽

Vol 70 ◽

pp. S99

Keyword(s):

Von Willebrand Factor ◽

Genetic Defect ◽

Von Willebrand Disease ◽

Type I ◽

Factor Gene ◽

Von Willebrand ◽

Willebrand Factor

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Platelet von Willebrand factor: evidence for its involvement in platelet adhesion to collagen

Blood ◽

10.1182/blood.v70.4.1214.bloodjournal7041214 ◽

1987 ◽

Vol 70 (4) ◽

pp. 1214-1217

Author(s):

E Fressinaud ◽

D Baruch ◽

C Rothschild ◽

HR Baumgartner ◽

D Meyer

Keyword(s):

Shear Rate ◽

Von Willebrand Factor ◽

Platelet Adhesion ◽

Von Willebrand Disease ◽

High Shear ◽

Shear Rates ◽

High Shear Rates ◽

Von Willebrand ◽

Willebrand Factor

Although it is well established that plasma von Willebrand Factor (vWF) is essential to platelet adhesion to subendothelium at high shear rates, the role of platelet vWF is less clear. We studied the respective role of both plasma and platelet vWF in mediating platelet adhesion to fibrillar collagen in a parallel-plate perfusion chamber. Reconstituted blood containing RBCs, various mixtures of labeled washed platelets and plasma from controls or five patients with severe von Willebrand disease (vWD), was perfused through the chamber for five minutes at a shear rate of 1,600 s-1. Platelet-collagen interactions were estimated by counting the radioactivity in deposited platelets and by quantitative morphometry. When the perfusate consisted of normal platelets suspended in normal plasma, platelet deposition on the collagen was 24.7 +/- 3.6 X 10(6)/cm2 (mean +/- SEM, n = 6). Significantly less deposition (16 +/- 2.3) was observed when vWD platelets were substituted for normal platelets. In mixtures containing vWD plasma, significantly greater deposition (9 +/- 2.2) was obtained with normal than with vWD platelets (1 +/- 0.4) demonstrating a role for platelet vWF in mediating the deposition of platelets on collagen. Morphometric analysis confirmed these data. Our findings indicate that platelet, as well as plasma, vWF mediates platelet-collagen interactions at a high shear rate.

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