Distinct Role of von Willebrand Factor Triplet Bands in Glycoprotein Ib-Dependent Platelet Adhesion and Thrombus Formation under Flow

SummaryVon Willebrand factor (vWF) plays an essential role in platelet adhesion and thrombus formation. Patients with atrial fibrillation (AF) exhibit higher plasma vWF and lower ADAMTS13 antigen levels compared to controls. Little is known about vWF and ADAMTS13 in AF patients treated with cardioversion (CV). Thus we investigated the alterations of plasma vWF and ADAMTS13 after CV and evaluated the predictive value of these parameters for recurrence of AF. In this observational study we determined plasma levels of vWF and ADAMTS13 in 77 patients before and immediately after CV, as well as 24 hours (h) and six weeks thereafter, by means of commercially available assays. The vWF/ ADAMTS13-ratio was significantly elevated immediately after CV (p=0.02) and 24 h after CV (p=0.002) as compared to baseline levels. ADAMTS13, 24 h after CV, exhibited a significant association with recurrence of AF (HR: 0.97; p=0.037). Accordingly, tertiles of ADAMTS13 showed a stepwise inverse correlation with the risk of recurrent AF (HR: 0.50; p=0.009). After adjustment for confounders, ADAMTS13 remained significant as an independent predictor of recurrent AF (HR: 0.61; p=0.047). Similarly, the vWF/ADAMTS13-ratio, 24 h after CV, was associated with rhythm stability and remained an independent predictor of recurrent AF (HR: 1.88; p=0.028). The regulation of vWF and its cleaving protease ADAMTS13 after CV might play a critical role in producing a pro-thrombotic milieu immediately after CV for AF. Since ADAMTS13 plasma concentration and the vWF/ADAMTS13-ratio are independently associated with rhythm stability, these indexes might be used for prediction of recurrence of AF.

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Partial characterization of a binding site for von Willebrand factor on glycocalicin

Blood ◽

10.1182/blood.v67.1.19.bloodjournal67119 ◽

1986 ◽

Vol 67 (1) ◽

pp. 19-26 ◽

Cited By ~ 1

Author(s):

AD Michelson ◽

J Loscalzo ◽

B Melnick ◽

BS Coller ◽

RI Handin

Keyword(s):

Binding Site ◽

Von Willebrand Factor ◽

Platelet Adhesion ◽

Binding Activity ◽

Proteolytic Fragment ◽

Von Willebrand ◽

Willebrand Factor ◽

Beta Galactosidase

The binding of von Willebrand factor (vWF) to platelet membrane glycoprotein Ib (GpIb) facilitates platelet adhesion to vascular subendothelium. In this study, we provide evidence that the vWF binding site is on glycocalicin (GC), a proteolytic fragment of GpIb, and we examine the role of the carbohydrate portion of GC on that binding. The binding to platelets of 6D1, a monoclonal antibody that recognizes an epitope on GpIb and blocks ristocetin-induced vWF binding to platelets, was inhibited by purified GC. In addition, purified GC inhibited ristocetin-dependent binding of 125I-labeled vWF to platelets. Since GC contains 60% carbohydrate by weight, we assessed the role of carbohydrate sequences on its interaction with antibody 6D1 and vWF. Based on the known sequence of the major oligosaccharide chain of GC--N- acetyl neuraminic acid, galactose, N-acetyl glucosamine, N-acetyl galactosamine--we treated GC sequentially with neuraminidase, beta- galactosidase, and beta-N-acetylglucosaminidase. Removal of sialic acid and galactose residues did not affect GC binding. Removal of N-acetyl glucosamine residues did not affect GC binding to 6D1 but did decrease the ability of GC to inhibit vWF binding to platelets, increasing the concentration needed to inhibit binding by 50% (IC50) 40-fold. This suggests that a portion of the oligosaccharide chains on GC contributes to the vWF binding activity of this molecule.

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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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Endothelial CD40 Mediates Microvascular von Willebrand Factor-Dependent Platelet Adhesion Inducing Inflammatory Venothrombosis in ADAMTS13 Knockout Mice

Thrombosis and Haemostasis ◽

10.1055/s-0040-1702228 ◽

2020 ◽

Vol 120 (03) ◽

pp. 466-476

Author(s):

Sibgha Tahir ◽

Andreas H. Wagner ◽

Steffen Dietzel ◽

Hanna Mannell ◽

Joachim Pircher ◽

...

Keyword(s):

Von Willebrand Factor ◽

Knockout Mice ◽

Platelet Adhesion ◽

Thrombus Formation ◽

Cd40 Ligand ◽

Inflammatory Conditions ◽

String Formation ◽

Von Willebrand ◽

Willebrand Factor

Abstract Background von Willebrand factor (vWF) plays an important role in platelet activation. CD40–CD40 ligand (CD40L) induced vWF release has been described in large vessels and cultured endothelium, but its role in the microcirculation is not known. Here, we studied whether CD40 is expressed in murine microvessels in vivo, whether CD40L induces platelet adhesion and leukocyte activation, and how deficiency of the vWF cleaving enzyme ADAMTS13 affects these processes. Methods and Results The role of CD40L in the formation of beaded platelet strings reflecting their adhesion to ultralarge vWF fibers (ULVWF) was analyzed in the murine cremaster microcirculation in vivo. Expression of CD40 and vWF was studied by immunohistochemistry in isolated and fixed cremasters. Microvascular CD40 was only expressed under inflammatory conditions and exclusively in venous endothelium. We demonstrate that CD40L treatment augmented the number of platelet strings, reflecting ULVWF multimer formation exclusively in venules and small veins. In ADAMTS13 knockout mice, the number of platelet strings further increased to a significant extent. As a consequence extensive thrombus formation was induced in venules of ADAMTS13 knockout mice. In addition, circulating leukocytes showed primary and rapid adherence to these platelet strings followed by preferential extravasation in these areas. Conclusion CD40L is an important stimulus of microvascular endothelial ULVWF release, subsequent platelet string formation and leukocyte extravasation but only in venous vessels under inflammatory conditions. Here, the lack of ADAMTS13 leads to severe thrombus formation. The results identify CD40 expression and ADAMTS13 activity as important targets to prevent microvascular inflammatory thrombosis.

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Microfibrils (MF) Platelet Interaction: Requirement Of Von Willebrand Factor In Platelet Adhesion To A Placenta Microfibrillar Component (PMC)

10.1055/s-0038-1652578 ◽

1981 ◽

Author(s):

F Fauvel ◽

Y J Legrand ◽

N Gutman ◽

J P Muh ◽

G Tobelem ◽

...

Keyword(s):

Von Willebrand Factor ◽

Platelet Adhesion ◽

Human Platelets ◽

Human Artery ◽

Von Willebrand ◽

Willebrand Factor ◽

Adhesion Of Platelets ◽

Aggregation Of Platelets

It has been shown that collagenase resistant arterial microfibrils (MF) are able to interact with platelets and therefore represents, besides collagen, a second thrombogenic structure in the vessel wall. In vitro observation using a PMC purified from the villosities of human placenta by a mechanical non denaturing procedure confirm this interaction between platelets and MF. PMC was homogenous under electron microscope (feltwork of MF with a mean diameter of 120 – 130 A) and was glycoproteic in nature. PMC were able to induce an aggregation of human platelets only if the platelets were in plasma. The role of Von Willebrand factor (F VIII/WF) as a cofactor of the aggregation of platelets by MF has been postulated from the fact that twice washed platelets from normal subject resuspended in PPP obtained from a severe Von Willebrand deficient patient were not aggregated by the PMC. Furthermore, aggregation was restored after resuspension of the same platelets in the PPP of the same patient 30 and 120 minutes after perfusion of cryoprecipitate (40 units F VIII/RA per kg).F VIII/WF mediates platelet adhesion after binding to subendothelium of human artery. Our observation strongly supports the idea that MF are the subendothelial components to which F VIII/WF binds, thus promoting an adhesion of platelets.

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418 Ultrasound molecular imaging of the role of von willebrand factor-mediated platelet adhesion in atherogenesis

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.232 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

K Ozawa ◽

M Muller ◽

O Varlamov ◽

W Packwood ◽

A Xie ◽

...

Keyword(s):

Molecular Imaging ◽

Von Willebrand Factor ◽

Platelet Adhesion ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Aortic Distensibility ◽

Research Fellowship ◽

Von Willebrand ◽

Willebrand Factor

Abstract Funding Acknowledgements JSPS Overseas Research Fellowship Background Platelets are known to be both pro-inflammatory and pro-mitogenic. However, the role of platelet-endothelial interactions in the initiation and growth of atherosclerotic lesions is not well understood. Purpose We used contrast-enhanced ultrasound (CEU) molecular imaging of the arterial endothelium to test the hypothesis that platelet attachment to endothelial Von Willebrand Factor (VWF) promotes atherogenesis. Methods We studied wild-type mice (WT), low-density lipoprotein deficient mice fed western diet to produce atherosclerosis (LDLR-/-), and LDLR-/- mice also deficient for ADAMTS-13 (LDLR-/-ADAMTS13-/-) which is the enzyme responsible for proteolytic cleavage of endothelial-associated VWF. Mice were studied at 20 weeks and 30 weeks of age. A subset of LDLR-/- mice were treated with recombinant ADAMTS13 1 hr prior to study. Proximal aortic CEU molecular imaging of P-selectin, vascular cell adhesion molecule (VCAM)-1, von Willebrand factor (VWF), and platelet GPIbα was performed. Aortic distensibility was assessed using high-frequency (30 MHz) transthoracic echocardiography and tail cuff blood pressure systems. NF-κB of aorta was assessed by ELISA kit. Plaque size and composition were assessed by histology. Platelets and macrophage immunohistochemistry were also performed on confocal microscopy. Results Aortic molecular imaging signal for P-selectin, VCAM-1, VWF, and platelet adhesion was significantly higher in LDLR-/- than WT mice, and increased by 2-fold between 20 and 30 wks of age. Signal for VWF and platelet adhesion was abolished 1 h after administration of ADAMTS13, confirming that platelet adhesion was VWF-mediated. At 20 and 30 wks of age, molecular imaging signal for all targets was 2-fold higher (p < 0.01) in LDLR-/-ADAMTS13-/- versus LDLR-/- mice. The LDLR-/-ADAMTS13-/- mice also had lower aortic distensibility (p < 0.05), had a 2-fold higher NF-κB signal (p < 0.05), and had a 2-fold greater total plaque area (p < 0.01). Fluorescent immunohistochemistry confirmed that the LDLR-/-ADAMTS13-/- mice also had greater platelets (p < 0.05) and increased macrophage content (p < 0.05) than LDLR-/- mice in aortic plaque. Conclusion In early to mid-stage atherosclerosis, abnormal regulation of endothelial-associated VWF results in platelet adhesion and secondary up-regulation of endothelial inﬂammatory adhesion molecules, thereby promoting atherosclerotic plaque progression. These results indicate an important role of platelet-endothelial interactions in early atherogenesis. Abstract 418 Figure

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A ROLE OF PLATELET MEMBRANE COMPONENTS IN THE INTERACTION OF PLATELET-COLLAGEN-VON WILLEBRAND FACTOR

10.1055/s-0038-1644480 ◽

1987 ◽

Author(s):

M Aihara ◽

S Morimoto ◽

Y Sawada ◽

A Kimura ◽

Y Chiba ◽

...

Keyword(s):

Von Willebrand Factor ◽

Platelet Adhesion ◽

Ricinus Communis ◽

Platelet Membrane ◽

Silver Stain ◽

Normal Plasma ◽

Membrane Components ◽

Von Willebrand ◽

Willebrand Factor

To determine a role of platelet membrane components on the interaction of platelet-collagen-von Willebrand factor(vWF), several experimental approaches were used. The adhesion of human fixed washed platelets(FWP) to collagen was decreased after the treatment with Serratia marcescens protease(100 ug/ml), but the collagen cofactor activity(COo) of vWF that enhances the adhesion of FWP to collagen was still present after the digestion. Although the platelet adhesion in the absence of normal plasma was not changed by the addition of monoclonal antibody(M-ab) against platelet membrane glycoprotein(GP) IIb/lIIa(1 0E5, BS Coller), the adhesion was decreased by 30-50% after the treatment of the platelets with 10-100 ug/ml anti-GPIb(6D1, BS Coller). The adhesion of FWP to collagen was inhibited by lectins;the adhesion was 58-75% in the presence of 100-400 ug/ml L. culinaris lectin or weat germ agglutinin and the adhesion was nil in the presence of 100 ug/ml Ricinus communis agglutinin I or 200 ug/ml concanavalin A. By the crossed aff ino-immunoelectrophoresis, the binding of GP Ilb/lIIa in Triton-solubilized platelet supernatant to the collagen spacer gel was observed. When CHAPSO solubilized platelet was applied to the collagen column and the fractions containing adhesion inhibitor were eluated by 0.3M NaCl, Mr of 240K, 220K, 21 OK, 116K, 61K, 54K, 50K and 45K proteins were identified besides the proteins which correspond to thrombospondin, GPIb, GP lib or Ilia by SDS-PAGE(7.5% gel, silver stain). GOo in normal plasma was not changed by anti-GPIIb/lIIa but was decreased to 32-38%by anti-GPIb. M-ab against vWF, CLB-RAg 35(van Mourik), that inhibits the binding of vWF to platelet by ristocetin decreased COo in normal plasma by 70% and CLB-RAg 201 (van Mourik) that inhibits the binding of vWF to collagen did completely inhibit the COo in normal plasma. In conclusion, our data suggest that (1) GPIb is partly involved in the platelet adhesion to collagen; (2) the binding of vWF to collagen is required for the expression of CCo; (3) CCo of vWF is partly mediated though GPIb; and (4) several platelet membrane protein(s) besides GPIb or GPIIb/lIIa may be also involved in both the adhesion of platelets to collagen and CCo of vWF.

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Glycoprotein Ibα and von Willebrand factor in primary platelet adhesion and thrombus formation: Lessons from mutant mice

Thrombosis and Haemostasis ◽

10.1160/th07-10-0638 ◽

2008 ◽

Vol 99 (02) ◽

pp. 264-270 ◽

Cited By ~ 50

Author(s):

Anil K. Chauhan ◽

Denisa D. Wagner ◽

Wolfgang Bergmeier

Keyword(s):

Von Willebrand Factor ◽

Platelet Adhesion ◽

Thrombus Formation ◽

Mutant Mice ◽

Receptor Complex ◽

Von Willebrand ◽

Willebrand Factor ◽

Primary Platelet ◽

Adhesion Process ◽

Main Ligand

SummaryThe von Willebrand factor (VWF) receptor complex, glycoprotein (GP)Ib-V-IX, and its main ligand VWF play a key role in the adhesion process of platelets to sites of vascular injury. Recent studies in mutant mice have shed new light on the importance of either molecule for the development of arterial and venous thrombosis. In this review, we summarize the most important aspects from these studies.

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Von Willebrand factor C1C2 domain is involved in platelet adhesion to polymerized fibrin at high shear rate

Blood ◽

10.1182/blood-2003-07-2267 ◽

2004 ◽

Vol 103 (5) ◽

pp. 1741-1746 ◽

Cited By ~ 25

Author(s):

Jeffrey F. W. Keuren ◽

Dominique Baruch ◽

Paulette Legendre ◽

Cécile V. Denis ◽

Peter J. Lenting ◽

...

Keyword(s):

Shear Rate ◽

Binding Site ◽

Von Willebrand Factor ◽

Platelet Adhesion ◽

Thrombus Formation ◽

High Shear Rate ◽

High Shear ◽

Perfusion Studies ◽

Von Willebrand ◽

Willebrand Factor

AbstractFibrin is actively involved in platelet reactions essential for thrombus growth, in which von Willebrand factor (VWF) might be an important mediator. The aim of this study was to localize VWF domains that bind to fibrin and to determine their relevance in platelet adhesion. VWF binds specifically to fibrin with an apparent Kd of 2.2 μg/mL. Competition in the presence of 2 complementary fragments, SpIII (residues 1-1365) and SpII (residues 1366-2050), indicated that the high affinity binding site for fibrin is located in the C-terminal part, thus distinct from the A domains. Comparison of 2 deleted rVWF (ΔD4B-rVWF, ΔC1C2-rVWF) suggested that the C1C2 domains contained a fibrin binding site. This site is distinct from RGD, as shown by binding of D1746G-rVWF to fibrin. Perfusion studies at high shear rate demonstrated that C1C2 domains were required for optimal platelet adhesion to fibrin. With the use of a VWF-deficient mouse model, it was found that plasma VWF is critical for platelet tethering and adhesion to fibrin. These results suggest a dual role of fibrin-bound VWF in thrombus formation: first, fibrin-bound VWF is critical in the recruitment of platelets by way of glycoprotein (GP) Ib, and, second, it contributes to stationary platelet adhesion by way of binding to activated αIIbβ3.

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