scholarly journals SIPA in 10 milliseconds: VWF tentacles agglomerate and capture platelets under high shear

2021 ◽  
Author(s):  
Zixiang Leonardo Liu ◽  
Christopher Bresette ◽  
Cyrus K Aidun ◽  
David N Ku
Keyword(s):  
In Silico ◽  
Carotid Arteries ◽  
High Shear ◽  
Normal Length ◽  
Shear Rates ◽  
Cellular Resolutions ◽  
High Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor

Shear-Induced Platelet Aggregation (SIPA) occurs under elevated shear rates (~10000 s-1) found in stenotic coronary and carotid arteries. The pathologically high-shear environment can lead to occlusive thrombosis by SIPA from the interaction of nonactivated platelets and von Willebrand factor (VWF) via glycoprotein Ib (GPIb)-A1 binding. This process under high shear rates is difficult to visualize experimentally with concurrent molecular- and cellular-resolutions. To understand this fast bonding, we employ a validated multiscale in-silico model incorporating measured molecular kinetics and a thrombosis-on-a-chip device to delineate the flow-mediated biophysics of VWF and platelets assembly into mural micro-thrombi. We show that SIPA begins with VWF elongation, followed by agglomeration of platelets in the flow by soluble VWF entanglement before mural capture of the agglomerate by immobilized VWF. The entire SIPA process occurs on the order of 10 ms with the agglomerate travelling a lag distance of a few hundred microns before capture, matching in vitro results. Increasing soluble VWF concentration by ~20x in silico leads to a 2~3x increase in SIPA rates, matching the increase in occlusion rates found in vitro. The morphology of mural aggregates is primarily controlled by VWF molecular weight (length), where normal-length VWF leads to cluster or elongated aggregates and ultra-long VWF leads to loose aggregates seen by others' experiments. Finally, we present phase diagrams of SIPA which provides biomechanistic rationales for a variety of thrombotic and hemostatic events in terms of platelet agglomeration and capture.

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.

Effect of recombinant von Willebrand factor reproducing type 2B or type 2M mutations on shear-induced platelet aggregation

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3796-3803 ◽  
Author(s):  
Nadine Ajzenberg ◽  
Anne-Sophie Ribba ◽  
Ghassem Rastegar-Lari ◽  
Dominique Meyer ◽  
Dominique Baruch
Keyword(s):  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Consistent Increase ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The aim was to better understand the function of von Willebrand factor (vWF) A1 domain in shear-induced platelet aggregation (SIPA), at low (200) and high shear rate (4000 seconds-1) generated by a Couette viscometer. We report on 9 fully multimerized recombinant vWFs (rvWFs) expressing type 2M or type 2B von Willebrand disease (vWD) mutations, characterized respectively by a decreased or increased binding of vWF to GPIb in the presence of ristocetin. We expressed 4 type 2M (-G561A, -E596K, -R611H, and -I662F) and 5 type 2B (rvWF-M540MM, -V551F, -V553M, -R578Q, and -L697V). SIPA was strongly impaired in all type 2M rvWFs at 200 and 4000 seconds-1. Decreased aggregation was correlated with ristocetin binding to platelets. In contrast, a distinct effect of botrocetin was observed, since type 2M rvWFs (-G561A, -E596K, and -I662F) were able to bind to platelets to the same extent as wild type rvWF (rvWF-WT). Interestingly, SIPA at 200 and 4000 seconds-1 confirmed the gain-of-function phenotype of the 5 type 2B rvWFs. Our data indicated a consistent increase of SIPA at both low and high shear rates, reaching 95% of total platelets, whereas SIPA did not exceed 40% in the presence of rvWF-WT. Aggregation was completely inhibited by monoclonal antibody 6D1 directed to GPIb, underlining the importance of vWF-GPIb interaction in type 2B rvWF. Impaired SIPA of type 2M rvWF could account for the hemorrhagic syndrome observed in type 2M vWD. Increased SIPA of type 2B rvWF could be responsible for unstable aggregates and explain the fluctuant thrombocytopenia of type 2B vWD.

Platelet function under high shear conditions

2009 ◽  
Vol 29 (01) ◽  
pp. 21-24 ◽  
Author(s):  
A. J. Reininger
Keyword(s):  
Blood Platelets ◽  
Immunoglobulin Superfamily ◽  
High Shear ◽  
Shear Rates ◽  
Collagen Receptors ◽  
High Shear Rates ◽  
Platelet Receptor ◽  
Flowing Blood ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryBlood platelets are the first line of defense against bleeding and as such involved in the haemostatic repair of damaged vasculature. Their true prowess seems to be displayed under high shear conditions where platelets interact with a variety of plasma proteins, all of which are tightly regulated to close the leak but at the same time prevent lumen occlusion and thromboembolism. The first task is to arrest fast flowing platelets on exposed collagen of the damaged subendothelial surface. Although platelets are endowed with several collagen receptors, most notably integrin ╒2b®1 and the immunoglobulin superfamily member GPVI, they can not arrest platelets at high shear rates. The latter requires binding of the platelet receptor GPIb╒to the A1-binding domain of von Willebrand factor (VWF), which first has to be immobilized from the flowing blood onto the site of injury. Under high shear conditions further accrual of newly arriving platelets again requires VWF, which has to bridge platelets not only to the exposed collagen but also to each other by being sandwiched between the multiple platelet layers of the haemostatic plug.

Platelet adhesion at high shear rates: The roles of von Willebrand factor/GPIb and the β1 integrin α2β1

1996 ◽  
Vol 81 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Harvey R. Gralnicks ◽  
Wendy S. Kramer ◽  
Laurie P. McKeown ◽  
Leonard Garfinkel ◽  
Amos Pinot ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Β1 Integrin ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor

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.

Soluble Monomeric Von Willebrand Factor A1A2A3 (R1450E) Mutant Fragment Enhances Shear-Induced Platelet Aggregation and Platelet Adhesion to Fibrin(ogen) Via αIIbβ3 Under High Shear Stress.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4025-4025
Author(s):  
Miguel A. Cruz ◽  
Katie E. Sowa ◽  
Scott M. Smith
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Surface Coverage ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Abstract 4025 Poster Board III-961 Recently, we described that the gain of function mutation R1450E in the A1 domain of von Willebrand factor (VWF) eliminates the formation of catch bond with glycoprotein (GP)Ibα, prolonging the bond lifetimes at low forces. Because those studies were performed with the mutant immobilized on a plastic surface, we further characterize the effect of this mutant on platelet function in solution and under shear stress. Both wild type (WT) and mutant A1A2A3 proteins were expressed in HEK293 cells and purified to homogeneity. The monomeric state of A1A2A3 proteins were assessed by gel filtration chromatography and neither of the proteins had formed dimers or any higher order aggregates. The recombinant A1A2A3 mutant bound spontaneously to GPIbα without the modulator ristocetin with a half-maximal binding observed at 65 ± 8 nM. This apparent dissociation constant was comparable to that of WT (50 ± 10 nM) in the presence of ristocetin. The mutant failed to induce spontaneous platelet aggregation under stirring conditions, and blocked 100% ristocetin-induced platelet agglutination (RIPA) at concentration of 250 nM. At the same concentration, the mutant increased shear-induced platelet aggregation (SIPA) at 500s-1 and 5000s-1 shear rates, reaching 42% and 66%, respectively, while SIPA did not exceed 18% in the presence of WT. The anti-αIIbβ3 antibody 7E3 blocked the effect of the mutant on SIPA. Blood was then incubated with the mutant (250 nM) and perfused over a surface coated with fibrin(ogen) at different shear rates. Blood containing WT resulted in <10% surface coverage by platelets after 1.5 minutes while platelets from blood containing the mutant rapidly bound covering 100% of the fibrin(ogen) surface area at 1500s-1. At shear rate of 2500s-1, surface coverage was 20% for the mutant and 0% for WT fragment. EDTA and antibodies 6D1 (GPIbα) and 10E5 (αIIbβ3) effectively blocked mutant-mediated platelet adhesion and thrombus formation under high shear rates. The addition of ristocetin (0.5 mg/ml) to whole blood prior perfusion reproduced the effect of the mutant. Here, we describe an A1A2A3 mutant that bound spontaneously to GPIbα but affected differently RIPA and SIPA. These results suggest that hydrodynamic forces directly act on the GPIbα-mutant A1A2A3 complex, regulating signaling. In addition, platelet activation induced by the binding of soluble mutant A1A2A3 or plasma VWF results in αIIbβ3-mediated platelet adhesion to fibrin(ogen) under high shear rates. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Identifying the start of a platelet aggregate by the shear rate and the cell-depleted layer

2019 ◽  
Vol 16 (159) ◽  
pp. 20190148 ◽  
Author(s):  
B. J. M. van Rooij ◽  
G. Závodszky ◽  
V. W. Azizi Tarksalooyeh ◽  
A. G. Hoekstra
Keyword(s):  
Thrombus Formation ◽  
Flow Simulation ◽  
Microfluidic Devices ◽  
High Shear ◽  
Macroscopic Models ◽  
Shear Rates ◽  
High Shear Rates ◽  
Platelet Aggregate ◽  
Von Willebrand

Computer simulations were performed to study the transport of red blood cells and platelets in high shear flows, mimicking earlier published in vitro experiments in microfluidic devices with high affinity for platelet aggregate formation. The goal is to understand and predict where thrombus formation starts. Additionally, the need of cell-based modelling in these microfluidic devices is demonstrated by comparing our results with macroscopic models, wherein blood is modelled as a continuous fluid. Hemocell, a cell-based blood flow simulation framework is used to investigate the transport physics in the microfluidic devices. The simulations show an enlarged cell-depleted layer at the site where a platelet aggregate forms in the experiments. In this enlarged cell-depleted layer, the probability to find a platelet is higher than in the rest of the microfluidic device. In addition, the shear rates are sufficiently high to allow for the von Willebrand factor to elongate in this region. We hypothesize that the enlarged cell-depleted layer combined with a sufficiently large platelet flux and sufficiently high shear rates result in an haemodynamic environment that is a preferred location for initial platelet aggregation.

VWF Concentrates - Does Size Really Matter - Von Willebrand Factor Function under Physiological Flow Conditions.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3138-3138
Author(s):  
Bruce A. Schwartz ◽  
Birte Fuchs ◽  
C. Fisseau ◽  
Craig M. Kessler ◽  
Christoph Kannicht
Keyword(s):  
Platelet Adhesion ◽  
Flow Chamber ◽  
High Shear ◽  
Flow Conditions ◽  
Shear Rates ◽  
Physiological Flow ◽  
High Shear Rates ◽  
Platelet Binding ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Introduction: The Von Willebrand Factor (VWF), is a very large glycoprotein present in human plasma essential for normal thrombus formation at sites of vascular injury. Blood coagulation is initiated by exposure of vessel wall components, e.g. collagen, followed by platelet tethering, activation and adhesion leading to the formation of a stable clot. All steps of blood coagulation occur in flowing blood under various conditions depending on vessel size. It is important to assess the function of a VWF concentrate under physiologic conditions. Under static or low shear conditions, platelets can bind directly to collagen without assistance of VWF, while the VWF is essential for mediation of platelet adhesion under high flow occurring in the arterial circulation. It has been assumed that multimer size plays an important role in this binding and in subsequent platelet adhesion. In this study we evaluated the binding of VWF of different multimeric structures to collagen and determined VWF-mediated platelet binding under low to high shear rates in a flow chamber model. Methods: A flow-chamber coated with human collagen was developed to mimic physiological flow conditions. A high purity VWF/factor VIII (FVIII) concentrate (Wilate®) and two other VWF/FVIII concentrates were tested at shear rates of 400 1700 and 4000 s−1 reproducing shear rates occurring in veins, small arteries and capillaries. Collagen-bound VWF was characterized by antigen determination (VWF:Ag) and multimer (MM) analysis. Binding of labeled platelets was visualized by a fluorescence microscope and surface coverage was quantified. Results: All VWF MMs independent of MM size were found to bind to collagen even under high shear rates. The amount of collagen-bound VWF:Ag and VWF-mediated platelet adhesion at 1700 s−1 differed significantly between the tested concentrates, when equal VWF:Ag amounts were applied. Conclusion: Binding of VWF to collagen does not depend on VWF MM size in this model even when measured under high shear rates. The differences in collagen-bound VWF:Ag and VWF-mediated platelet binding do not seem to depend on the VWF MM distribution of the concentrates. Other structural features than VWF MM size may likely be caused by the differences seen in the binding levels of the different concentrates and should be further explored. Possible differences between VWF activity assays performed under static or flow conditions and their appropriate use for VWD diagnosis and quantification of in-vivo activity need to be further investigated.

Sign in / Sign up

Export Citation Format

Share Document