Shear Induced Reversible Conglomerates of Von Willebrand Factor Networks with Aggregates of Inactivated Platelets - a Fast Switchable Plugging Mechanism

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2104-2104
Author(s):  
Armin J. Reininger ◽  
Marina Napoleone ◽  
Jennifer Angerer ◽  
Babak Falah ◽  
Reinhard Schneppenheim ◽  
...  
Keyword(s):  
Shear Rate ◽  
Von Willebrand Factor ◽  
Conflicts Of Interest ◽  
Arterial Stenosis ◽  
Critical Threshold ◽  
Simultaneous Formation ◽  
Shear Rates ◽  
Platelet Aggregates ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Abstract 2104 Thrombus growth rate has been reported to be a linear function of very high shear rates beyond 40,000 s-1 (Ku DN, Bioreology. 2007;44(4):273-84), which are thought to occur in severe arterial stenosis. We therefore applied shear rates continuously increasing from 2,000 s-1 to 40,000 s-1 and examined platelet and von Willebrand factor (VWF) interaction in a parallel plate flow chamber under direct visualization. Above a critical threshold of 10,000 to 15,000 s-1 aggregates of inactivated platelets formed when VWF was present in solution and immobilized on the perfused surface (Ruggeri, … Reininger; Blood, 108: 1903–1910, 2006). A new finding was the shear dependent simultaneous formation of VWF strands in and around those platelet aggregates, growing to strands up to several microns thick and up to several tens of microns long, thus forming large VWF networks. Platelets appeared to be enmeshed in the VWF networks but were nevertheless a prerequsite for their formation, mutually fostering each other. Platelet-VWF conglomerates formed at the perfused VWF surface, were constantly rolling in the flow direction, grew in size with increasing shear rate, and were completely reversible below the critical shear rate threshold of 10,000 s-1. VWF networks assembled in whole blood as well as in washed blood cell suspensions reconstituted with VWF. Recombinant full length VWF generated larger VWF networks than a commercial VWF preparation from pooled human plasma. Perfusion of collagen coated surfaces caused assembly of VWF networks anchored to the collagen fibrils and capture of activation-blocked platelets within them at shear rates of 2,000 s-1, leading to residence times of platelet-VWF conglomerates of more than a minute. Newly formed platelet conglomerates could be visualized rolling on the surfaces of already attached conglomerates. When we used a gain of function mutation of VWF, rolling platelet aggregates could be detected at a shear rate as low as 1,500 s-1. We conclude that shear rate activation of VWF leads to reversible platelet-VWF network generation, which may be a crucial mechanism of fast platelet accrual and prolonged arrest times at sites of thrombosis as well as physiological hemostasis. Disclosures: No relevant conflicts of interest to declare.

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

Blood ◽  
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.

scholarly journals Von Willebrand factor in the vessel wall mediates platelet adherence

Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 85-90 ◽  
Author(s):  
HV Stel ◽  
KS Sakariassen ◽  
PG de Groot ◽  
JA van Mourik ◽  
JJ Sixma
Keyword(s):  
Monoclonal Antibody ◽  
Shear Rate ◽  
Von Willebrand Factor ◽  
Vessel Wall ◽  
Human Artery ◽  
Shear Rates ◽  
Platelet Adherence ◽  
Wall Shear ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII- vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. This monoclonal antibody, CLB-RAg 35, inhibited platelet adherence as a function of the shear rate. At wall shear rates below 500 s-1, platelet adherence was not affected, but at higher shear rates platelet adherence was gradually inhibited, reaching an average of 11% of the normal value at 2,500 s-1. Indirect immunofluorescence established the reactivity of CLB-RAg 35 with vWF present in artery subendothelium. Pretreatment of normal vessel walls with this antibody inhibited adherence of platelets in blood from a patient with severe homozygous von Willebrand's disease and in blood from normal individuals. The inhibition was shear-rate dependent and significant at high shear rates (2,500 s-1). By adding increasing amounts of purified FVIII-vWF to normal blood, the inhibition was gradually overcome. These data indicate that vWF present in the vessel wall contributes appreciably to platelet adherence. At high wall shear rates, platelet adherence is mediated virtually completely by both plasma FVIII-vWF and vWF in the vessel wall. At low wall shear rates (below 500 s-1), platelet adherence occurs independent of FVIII-vWF in plasma and vWF in the vessel wall.

scholarly journals Von Willebrand factor in the vessel wall mediates platelet adherence

Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 85-90 ◽  
Author(s):  
HV Stel ◽  
KS Sakariassen ◽  
PG de Groot ◽  
JA van Mourik ◽  
JJ Sixma
Keyword(s):  
Monoclonal Antibody ◽  
Shear Rate ◽  
Von Willebrand Factor ◽  
Vessel Wall ◽  
Human Artery ◽  
Shear Rates ◽  
Platelet Adherence ◽  
Wall Shear ◽  
Von Willebrand ◽  
Willebrand Factor

A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII- vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. This monoclonal antibody, CLB-RAg 35, inhibited platelet adherence as a function of the shear rate. At wall shear rates below 500 s-1, platelet adherence was not affected, but at higher shear rates platelet adherence was gradually inhibited, reaching an average of 11% of the normal value at 2,500 s-1. Indirect immunofluorescence established the reactivity of CLB-RAg 35 with vWF present in artery subendothelium. Pretreatment of normal vessel walls with this antibody inhibited adherence of platelets in blood from a patient with severe homozygous von Willebrand's disease and in blood from normal individuals. The inhibition was shear-rate dependent and significant at high shear rates (2,500 s-1). By adding increasing amounts of purified FVIII-vWF to normal blood, the inhibition was gradually overcome. These data indicate that vWF present in the vessel wall contributes appreciably to platelet adherence. At high wall shear rates, platelet adherence is mediated virtually completely by both plasma FVIII-vWF and vWF in the vessel wall. At low wall shear rates (below 500 s-1), platelet adherence occurs independent of FVIII-vWF in plasma and vWF in the vessel wall.

scholarly journals Glycoprotein Ib, von Willebrand factor, and glycoprotein IIb:IIIa are all involved in platelet adhesion to fibrin in flowing whole blood

Blood ◽  
1990 ◽  
Vol 76 (2) ◽  
pp. 345-353 ◽  
Author(s):  
RR Hantgan ◽  
G Hindriks ◽  
RG Taylor ◽  
JJ Sixma ◽  
PG de Groot
Keyword(s):  
Platelet Aggregation ◽  
Shear Rate ◽  
Von Willebrand Factor ◽  
Whole Blood ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Shear Rates ◽  
Wall Shear ◽  
Von Willebrand ◽  
Willebrand Factor

We have investigated the molecular basis of thrombus formation by measuring the extent of platelet deposition from flowing whole blood onto fibrin-coated glass coverslips under well-defined shear conditions in a rectangular perfusion chamber. Platelets readily and specifically adhered to fibrin-coated coverslips in 5 minute perfusion experiments done at either low (300 s-1) or high (1,300 s-1) wall shear rates. Scanning electron microscopic examination of fibrin-coated coverslips after perfusions showed surface coverage by a monolayer of adherent, partly spread platelets. Platelet adhesion to fibrin was effectively inhibited by a monoclonal antibody (MoAb) specific for glycoprotein (GP) IIb:IIIa. The dose-response curve for inhibition of adhesion by anti-GPIIb:IIIa at both shear rates paralleled that for inhibition of platelet aggregation. Platelet aggregation and adhesion to fibrin were also blocked by low concentrations of prostacyclin. In contrast, anti- GPIb reduced adhesion by 40% at 300 s-1 and by 70% at 1,300 s-1. A similar pattern of shear rate-dependent, incomplete inhibition resulted with a MoAb specific for the GPIb-recognition region of von Willebrand factor (vWF). Platelets from an individual with severe von Willebrand's disease, whose plasma and platelets contained essentially no vWF, exhibited defective adhesion to fibrin, especially at the higher shear rate. Addition of purified vWF restored adhesion to normal values. These results are consistent with a two-site model for platelet adhesion to fibrin, in which the GPIIb:IIIa complex is the primary receptor, with GPIb:vWF providing a secondary adhesion pathway that is especially important at high wall shear rates.

scholarly journals Shear Stress-Induced Activation of von Willebrand Factor and Cardiovascular Pathology

2020 ◽  
Vol 21 (20) ◽  
pp. 7804
Author(s):  
Sergey Okhota ◽  
Ivan Melnikov ◽  
Yuliya Avtaeva ◽  
Sergey Kozlov ◽  
Zufar Gabbasov
Keyword(s):  
Cardiovascular Diseases ◽  
Von Willebrand Factor ◽  
Plasma Levels ◽  
Coagulation Factor ◽  
Arterial Stenosis ◽  
Heart Valve Disease ◽  
Cardiovascular Pathology ◽  
Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor

The von Willebrand factor (vWF) is a plasma protein that mediates platelet adhesion and leukocyte recruitment to vascular injury sites and carries coagulation factor VIII, a building block of the intrinsic pathway of coagulation. The presence of ultra-large multimers of vWF in the bloodstream is associated with spontaneous thrombosis, whereas its deficiency leads to bleeding. In cardiovascular pathology, the progression of the heart valve disease results in vWF deficiency and cryptogenic gastrointestinal bleeding. The association between higher plasma levels of vWF and thrombotic complications of coronary artery disease was described. Of note, it is not the plasma levels that are crucial for vWF hemostatic activity, but vWF activation, triggered by a rise in shear rates. vWF becomes highly reactive with platelets upon unfolding into a stretched conformation, at shear rates above the critical value (more than 5000 s−1), which might occur at sites of arterial stenosis and injury. The activation of vWF and its counterbalance by ADAMTS-13, the vWF-cleaving protease, might contribute to complications of cardiovascular diseases. In this review, we discuss vWF involvement in complications of cardiovascular diseases and possible diagnostic and treatment approaches.

Modulation of von Willebrand Factor A1 Domain-Mediated Platelet Aggregation/Agglutination by α-Thrombin.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 628-628
Author(s):  
Grazia Loredana Mendolicchio ◽  
Reha Celikel ◽  
Kottayil I. Varughese ◽  
Brian Savage ◽  
Zaverio M. Ruggeri
Keyword(s):  
Platelet Aggregation ◽  
Shear Rate ◽  
Von Willebrand Factor ◽  
Platelet Glycoprotein ◽  
Shear Rates ◽  
Amino Terminal ◽  
Low Responder ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Evaluation of the crystal structures of the amino terminal domain of platelet glycoprotein (GP) Ibα bound to the von Willebrand factor A1 domain (VWFA1) or to α-thrombin indicate the absence of significant steric hindrance in a putative triple complex of the two ligands interacting with the same receptor molecule. Superposition of the models reveals that intermolecular contacts may be established between VWFA1 and α-thrombin concurrently bound to GP Ibα, and suggests that these additional interactions could stabilize the intrinsically low affinity binding of the VWF A1 domain. To verify the predictions of the model, we used gel electrophoresis under native conditions and purified components in solution to demonstrate directly the formation of a triple complex. We then sought to evaluate whether α-thrombin could influence the functional effects of the VWF-GP Ibα interaction. For this purpose, we established a model of platelet agglutination/aggregation dependent on the interaction between recombinant dimeric VWFA1 domain, purified from the culture medium of stably transfected D. melanogaster cell lines, and GP Ibα. In this assay, platelet rich plasma prepared from individual donor blood collected with the thrombin inhibitor D-phenyl alanyl-L-prolyl-L-arginine chloromethyl ketone dihydrochloride (PPACK) as an anticoagulant (80 μM) was mixed with varying concentrations of dimeric VWFA1 (0.5-10 μg/ml) and exposed to variable shear rate levels in a cone-and-plate viscometer. Platelet aggregation was observed at shear rates between 6 and 108 dyn/cm2. The response in different normal controls was reproducible but variable in extent, and individuals could be assigned to one of two categories, low responder and high responder. An agglutination response was observed after platelets were treated with 10 μM prostaglandin E1 to block activation, and the distinction between low and high responders remained true under these conditions. For simplicity, agglutinated platelets were still defined as “aggregates”. With activation blocked platelets, aggregates were stable up to a shear rate of 30 dyn/cm2, but began to dissipate at higher levels. The addition of α-thrombin with the active site irreversibly blocked by PPACK at concentrations between 5 and 10 μg/ml substantially increased the extent of the platelet response. This was demonstrated by a faster rate of platelet agglutination/aggregation, a greater stability of aggregates at higher shear rates, and an overall increase in the size of aggregates formed. To demonstrate the latter, samples were exposed to shear stress under selected conditions and immediately fixed with 1% glutaraldehyde for quantitative image analysis. Maximum aggregate size was increased several fold in the presence of α-thrombin, and the difference was particularly evident in low responder individuals in whom dimeric VWFA1 alone caused the formation of small and unstable aggregates. PPACK-blocked thrombin by itself had no effect on platelet aggregate formation at any shear rate tested. Our findings delineate a mechanism through which α-thrombin may stabilize platelet-platelet contacts by mediating a tighter association between VWF A1 domain and GP Ibα receptor. Such a function, independent of proteolytic activity, may enhance platelet deposition at sites of vascular injury.

scholarly journals Glycoprotein Ib, von Willebrand factor, and glycoprotein IIb:IIIa are all involved in platelet adhesion to fibrin in flowing whole blood

Blood ◽  
1990 ◽  
Vol 76 (2) ◽  
pp. 345-353 ◽  
Author(s):  
RR Hantgan ◽  
G Hindriks ◽  
RG Taylor ◽  
JJ Sixma ◽  
PG de Groot
Keyword(s):  
Platelet Aggregation ◽  
Shear Rate ◽  
Von Willebrand Factor ◽  
Whole Blood ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Shear Rates ◽  
Wall Shear ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract We have investigated the molecular basis of thrombus formation by measuring the extent of platelet deposition from flowing whole blood onto fibrin-coated glass coverslips under well-defined shear conditions in a rectangular perfusion chamber. Platelets readily and specifically adhered to fibrin-coated coverslips in 5 minute perfusion experiments done at either low (300 s-1) or high (1,300 s-1) wall shear rates. Scanning electron microscopic examination of fibrin-coated coverslips after perfusions showed surface coverage by a monolayer of adherent, partly spread platelets. Platelet adhesion to fibrin was effectively inhibited by a monoclonal antibody (MoAb) specific for glycoprotein (GP) IIb:IIIa. The dose-response curve for inhibition of adhesion by anti-GPIIb:IIIa at both shear rates paralleled that for inhibition of platelet aggregation. Platelet aggregation and adhesion to fibrin were also blocked by low concentrations of prostacyclin. In contrast, anti- GPIb reduced adhesion by 40% at 300 s-1 and by 70% at 1,300 s-1. A similar pattern of shear rate-dependent, incomplete inhibition resulted with a MoAb specific for the GPIb-recognition region of von Willebrand factor (vWF). Platelets from an individual with severe von Willebrand's disease, whose plasma and platelets contained essentially no vWF, exhibited defective adhesion to fibrin, especially at the higher shear rate. Addition of purified vWF restored adhesion to normal values. These results are consistent with a two-site model for platelet adhesion to fibrin, in which the GPIIb:IIIa complex is the primary receptor, with GPIb:vWF providing a secondary adhesion pathway that is especially important at high wall shear rates.

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

Blood ◽  
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

Abstract 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.

scholarly journals Size regulation of von Willebrand factor–mediated platelet thrombi by ADAMTS13 in flowing blood

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 1943-1950 ◽  
Author(s):  
Roberta Donadelli ◽  
Jennifer N. Orje ◽  
Cristina Capoferri ◽  
Giuseppe Remuzzi ◽  
Zaverio M. Ruggeri
Keyword(s):  
Shear Stress ◽  
Von Willebrand Factor ◽  
Cluster Size ◽  
Blood Perfusion ◽  
Shear Rates ◽  
Platelet Aggregates ◽  
Flowing Blood ◽  
Platelet Thrombi ◽  
Von Willebrand ◽  
Willebrand Factor

The metalloproteinase ADAMTS13 regulates the size of released von Willebrand factor (VWF) multimers bound to endothelial cells, but it is unknown whether it can cleave plasma VWF during thrombogenesis. To address this issue, we perfused blood over immobilized VWF and used videomicroscopy to visualize an activation-independent platelet aggregation process mediated by soluble VWF at shear rates greater than 10 000 s-1. At normal Ca2+ concentration, platelets formed rolling as well as surface-attached clusters that grew larger during the first 5 minutes but then lost more than 70% of their mass by 10 minutes. In contrast, platelet clusters were stable in size when metal ions were chelated, anti-ADAMTS13 IgG were added, or washed blood cells were perfused with purified VWF but no plasma. In the latter case, addition of recombinant ADAMTS13 reduced platelet cluster size by more than 70%. Incubating ADAMTS13 with VWF before perfusion did not prevent the initial platelet clustering, indicating that the enzyme may act on platelet-bound VWF under shear stress. At the concentrations tested, ADAMTS13 had no effect on platelet aggregates formed upon blood perfusion over collagen fibrils. ADAMTS13, therefore, may regulate thrombus size preferentially when the cohesion between platelets depends on VWF binding induced by pathologically elevated shear stress.

Synthetic RGDS-Containing Peptides of von Willebrand Factor Inhibit Platelet Adhesion to Collagen

1990 ◽  
Vol 64 (04) ◽  
pp. 589-593 ◽  
Author(s):  
Edith Fressinaud ◽  
Jean Pierre Girma ◽  
J Evan Sadler ◽  
Hans R Baumgartner ◽  
Dominique Meyer
Keyword(s):  
Shear Rate ◽  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Synergetic Effect ◽  
Dependent Manner ◽  
Shear Rates ◽  
Platelet Receptor ◽  
Adhesive Proteins ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe compared the effect of a synthetic dodecapeptide of residues 400-411 of the Γ chain of fibrinogen (Γ Fg 400-411) and of three synthetic peptides (15 to 18 aminoacids), of human von Willebrand Factor (vWF), containing the 1744-1747 Arg-Gly-Asp-Ser (RGDS) sequence, upon platelet adhesion to collagen in flowing blood. Both types of peptides are known to inhibit the binding of adhesive proteins to platelet membrane glycoprotein Ilb/IIIa (GPIIb/IIIa). Collagen was coated onto plastic cover slips and exposed in parallel-plate perfusion chambers to reconstituted human blood at various shear rates for 5 min at 37 °C. At a shear rate of 2,600 s−1, RGDS peptides inhibited platelet adhesion to collagen in a dose-dependent manner and appeared to be more potent inhibitors than the Γ Fg 400-411 on a molar basis. No synergetic effect between RGDS and Γ Fg 400-411 peptides was observed. These results suggest that the RGDS peptides affect adhesion by inhibiting the GPIIb/IIIa-vWF interaction and confirm the involvement of this platelet receptor in vWF-mediated platelet adhesion to collagen at high shear rate.

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