Contribution of Distinct Adhesive Interactions to Platelet Aggregation in Flowing Blood

Blood ◽  
1999 ◽  
Vol 94 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Zaverio M. Ruggeri ◽  
Judith A. Dent ◽  
Enrique Saldı́var
Keyword(s):  
Blood Platelets ◽  
Three Dimensional ◽  
Specific Function ◽  
Flow Conditions ◽  
Shear Rates ◽  
Dimensional Growth ◽  
Flowing Blood ◽  
Adhesive Interactions ◽  
Von Willebrand ◽  
Willebrand Factor

Aggregation of blood platelets contributes to the arrest of bleeding at sites of vascular injury, but it can occlude atherosclerotic arteries and precipitate diseases such as myocardial infarction. The bonds that link platelets under flow conditions were identified using confocal videomicroscopy in real time. Glycoprotein (GP) Ib and von Willebrand factor (vWF) acted in synergy with IIbβ3 and fibrinogen to sustain platelet accrual at the apex of thrombi where three-dimensional growth resulted in increasing shear rates. The specific function of distinct adhesion pathways in response to changing hemodynamic conditions helps to explain hemostatic and thrombotic processes.

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.

scholarly journals Uremic platelets have a functional defect affecting the interaction of von Willebrand factor with glycoprotein IIb-IIIa

Blood ◽  
1990 ◽  
Vol 76 (7) ◽  
pp. 1336-1340 ◽  
Author(s):  
G Escolar ◽  
A Cases ◽  
E Bastida ◽  
M Garrido ◽  
J Lopez ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Indirect Evidence ◽  
Flow Conditions ◽  
Experimental Conditions ◽  
Shear Rates ◽  
Functional Defect ◽  
Uremic Patients ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Uremic patients have an impaired platelet function that has been related to membrane glycoprotein (GP) abnormalities. Using a perfusion system, we have studied the interaction of normal and uremic platelets with vessel subendothelium (SE) under flow conditions. Reconstituted blood containing washed platelets, purified von Willebrand factor (vWF) (1 U/mL), and normal washed red blood cells was exposed to de- endothelialized rabbit segments for 10 minutes at two different shear rates (800 and 1,600 seconds-1). In some experiments a monoclonal antibody to the GPIIb-IIIa complex (EDU3) was added to the perfusates. With normal platelets, the percentage of the vessel covered by platelets (%CS) was 23.1% +/- 3.7% at 800 seconds-1 and 30% +/- 4.3% at 1,600 seconds-1. Platelets were observed in contact or forming monolayers on vessel SE. EDU3 inhibited the spreading of normal platelets. The %CS (11.1% +/- 3.3%) was statistically decreased (P less than .01) and most of the platelets were observed in contact with the vessel surface. These data indicate that, under flow conditions, the interaction of vWF with GPIIb-IIIa can support the spreading of normal platelets in the absence of exogenous fibrinogen. Under the same experimental conditions, the interaction of uremic platelets with SE was markedly impaired at both shear rates studied (P less than .01 v normal platelets). The presence of EDU3 did not modify the interaction of uremic platelets. These results confirm the impairment of the platelet adhesion observed in uremic patients. Furthermore, they indicate the presence of a functional defect in the interaction of vWF with GPIIb-IIIa. The fact that perfusions with normal and uremic platelets in the presence of an antibody to the GPIIb-IIIa complex did not show any differences gives indirect evidence on a functionally normal interaction vWF/GPIb in uremic patients.

scholarly journals Calin from Hirudo medicinalis, an inhibitor of von Willebrand factor binding to collagen under static and flow conditions

Blood ◽  
1995 ◽  
Vol 85 (3) ◽  
pp. 705-711 ◽  
Author(s):  
J Harsfalvi ◽  
JM Stassen ◽  
MF Hoylaerts ◽  
E Van Houtte ◽  
RT Sawyer ◽  
...  
Keyword(s):  
Shear Stress ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
High Shear ◽  
High Shear Stress ◽  
Flow Conditions ◽  
Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Low Shear

Calin from the saliva of the medicinal leech, Hirudo medicinalis, is a potent inhibitor of collagen mediated platelet adhesion and activation. In addition to inhibition of the direct platelet-collagen interaction, we presently demonstrate that binding of von Willebrand to coated collagen can be prevented by Calin, both under static and flow conditions in agreement with the occurrence of binding of Calin to collagen, confirmed by Biospecific Interaction Analysis. To define whether Calin acted by inhibiting the platelet-collagen or the platelet- von Willebrand factor (vWF)-collagen-mediated thrombus formation, platelet adhesion to different types of collagens was studied in a parallel-plate flow chamber perfused with whole blood at different shear rates. Calin dose-dependently prevented platelet adhesion to the different collagens tested both at high- and low-shear stress. The concentration of Calin needed to cause 50% inhibition of platelet adhesion at high-shear stress was some fivefold lower than that needed for inhibition of vWF-binding under similar conditions, implying that at high-shear stress, the effect of Calin on the direct platelet- collagen interactions, suffices to prevent thrombus formation. Platelet adhesion to extracellular matrix (ECM) of cultured human umbilical vein endothelial cells was only partially prevented by Calin, and even less so at a high-shear rather than a low-shear rate, whereas the platelet binding to coated vWF and fibrinogen were minimally affected at both shear rates. Thus, Calin interferes with both the direct platelet- collagen interaction and the vWF-collagen binding. Both effects may contribute to the inhibition of platelet adhesion in flowing conditions, although the former seems to predominate.

ASIALO VON WILLEBRAND FACTOR ENHANCES PLATELET ADHESION TO VASCULAR SUBENDOTHELIUM

1987 ◽  
Author(s):  
A Ordinas ◽  
E Bastida ◽  
M Garrido ◽  
J Monteagudo ◽  
L de Marco ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Human Albumin ◽  
Flow Conditions ◽  
Shear Rates ◽  
High Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Adhesion Of Platelets

Native Von Willebrand factor (NvWF) binds to platelets activated by thrombin, ADP or ristocetin, and also supports the adhesion of platelets to subendothelium at high shear rates. In contrast, asialo von Willebrand factor (AvWF) induces platelet aggregation in absence of platelet activators. We investigated the role of AvWF in supporting the adhesion of platelets to rabbit vessel subendothelium under flow conditions at a shear rate of 2000 sec-1 for 5 min using the Baumgartner perfusion system. We also studied the effects of blockage of platelet GPIb or GPIIb/IIIa on platelet adhesion using monoclonal antibodies (Mabs),and we measured the rate of binding of 111I-labeled NvWF and AvWF to subendothelium. Perfusates consisted of washed platelts and red cells resuspended in a 4% human albumin solution to which increasing concentrations of NvWF or AvWF had been added. Platelets interacting with the perfused vessels were evaluated morphometrically using a computerized system. At a concentration of 1.2 /ig/ml the percentage of total coverage surface was 21.3 ± 4.8% and 40.0±14.6%, for NvWF and AvWF, respectively (p<0.01). Addition of either Mab against GPIb (LJlbl) or against GPIIb/IIIa (CP8) to the perfusates, reduced platelet deposition (p <0.01). The rates of binding of 111I-labeled NvWF and AvWF to perfused vessel subendothelium were similar (0.83±0.1μg and 0.95±0.1 μg ,respectively).Our results indicate that AvWF enhances the interaction of washed platelets with the vessel subendothelium under flow conditions. Furthermore, they suggest that this effect is related to the interaction of AvWF with platelets and not to an increased affinity of AvWF for subendothelium.

Fluid Dynamical Considerations of Platelet-Vessel Wall Interaction

1979 ◽  
Author(s):  
V.T. Turitto
Keyword(s):  
Shear Rate ◽  
Platelet Adhesion ◽  
Relative Magnitude ◽  
Physical Factors ◽  
Shear Rates ◽  
Adhesion Rate ◽  
Flowing Blood ◽  
Wall Interaction ◽  
Von Willebrand ◽  
Willebrand Factor

Platelet adhesion to subendothelium is dependent on two distinct processes: (1) diffusive transport (T) of platelets to the surface and (2) platelet-subendothelial reactivity (R). The relative magnitude of T to R will determine which factors control the adhesion rate. Physical factors, specifically, wall shear rate (γ) and platelet diffusivity (D) influence T, whereas chemical alterations modify R. An increase in the magnitude of γ or D or a decrease in R tends toward R controlled adhesion. An increase in low rate or decrease in vessel dimensions increases γ, whereas D increases with both red cell concentration (up to 40 %) and γ.In flowing blood at shear rates comparable to those found in veins or large arteries (< 650 see-1), T determines platelet adhesion. Moderate alterations in R, such as produced by the addition to blood of 45 mM citrate, 10-100 nM prostacyclin or in von Willebrand factor depleted blood, have little effect on platelet adhesion values under these flow conditions. However, as shear rate is increased to values comparable to those in the microcirculation {1300-2600 sec-1), the same blood samples show values of platelet adhesion which are reduced compared to controls, and the reduction increases with shear rate Thus, measurements of R should be determined under controlled shear conditions which are high enough to be outside the range of predominantly transport controlled adhesion.

scholarly journals Platelet Adhesion to Collagen Type I, Collagen Type IV, von Willebrand Factor, Fibronectin, Laminin and Fibrinogen: Rapid Kinetics under Shear

1999 ◽  
Vol 81 (01) ◽  
pp. 118-123 ◽  
Author(s):  
Carl Simon ◽  
Adrian Gear ◽  
Renata Polanowska-Grabowska
Keyword(s):  
Shear Rate ◽  
Platelet Adhesion ◽  
Collagen Type ◽  
Lag Phase ◽  
Type I ◽  
Flow Conditions ◽  
Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Kinetics Of

SummaryExtracellular matrix proteins in the blood vessel wall fulfill an essential role in haemostasis by promoting platelet adhesion at the site of vessel injury. We have combined a continuous-flow system with affinity chromatography to study platelet adhesion under conditions mimicking arterial flow and have examined the adhesion kinetics of unstimulated platelets to collagens type I and IV, von Willebrand factor (vWf), fibronectin, laminin and to fibrinogen. In the absence of red cells, in ACD-prepared plasma adhesion to collagens type I and IV or vWf was rapid, efficient (>50% in <1 s ) and independent of shear rates from 650 to 3400 s-1with kinetics following an inverse exponential decay curve. We introduced a simple mathematical model in which this type of kinetics arises, and which may be more generally applicable to various adhesion processes under flow conditions. The model is characterized by the rate of platelet deposition on the adhesive surface being proportional to the number of platelets in the flow. Adhesion to fibronectin was independent of shear rate, but revealed a lag phase of ~1.5 s before significant adhesion began. Laminin and fibrinogen supported efficient adhesion at low shear rates (650-1000 s-1), but a lag phase of ~1.5 s was seen at high shear rates (1700-3400 s-1). Control proteins (albumin and gelatin) supported minimal adhesion. Nonspecific adhesion to poly-l-lysine differed from that to other substrate proteins in that the kinetics were linear. In conclusion, human platelets adhered specifically, rapidly (within seconds) and efficiently to several proteins under flow conditions and the kinetics of adhesion depended on the protein serving as substrate as well as on shear rate.

scholarly journals Platelet adhesion to laminin: role of Ca2+ and Mg2+ ions, shear rate, and platelet membrane glycoproteins

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 928-935 ◽  
Author(s):  
G Hindriks ◽  
MJ Ijsseldijk ◽  
A Sonnenberg ◽  
JJ Sixma ◽  
PG de Groot
Keyword(s):  
Shear Rate ◽  
Platelet Adhesion ◽  
Divalent Cations ◽  
Platelet Membrane ◽  
Flow Conditions ◽  
Membrane Glycoproteins ◽  
Shear Rates ◽  
The Matrix ◽  
Von Willebrand ◽  
Willebrand Factor

The adhesion of platelets to purified laminin under flow conditions was investigated. Adhesion to laminin was strongly dependent on the presence of divalent cations. In the absence of cations platelet adhesion (8% coverage in 5 minutes) was maximal at a shear rate of 100/s and no adhesion could be detected at shear rates above 800/s. In the presence of 0.8 mmol/L Mg2+ and 2 mmol/L Ca2+ platelet adhesion reached its maximum (30% coverage) around 800/s. At 1,800/s platelets still adhered to purified laminin (coverage of 6%). Antibodies against the E8 domain of laminin and antibodies against the alpha 6 and beta 1 chains of platelet membrane glycoprotein very late activation antigen-6 (VLA-6), completely inhibited adhesion. No inhibition was found with antibodies against glycoprotein IIb:IIIa, against the alpha 2 chain of VLA-2, and against the alpha 5 chain of VLA-5. Fibronectin and von Willebrand factor were not involved in laminin-dependent adhesion. Anti- VLA-6 partly inhibited platelet adhesion to the extracellular matrix of endothelial cells at shear rates below 800/s. Preincubation of the matrices with antilaminin E8 antibodies did not influence the adhesion. These results show that purified laminin supports platelet adhesion and that the presence of VLA-6 is important for platelet adhesion under flow conditions. The protein in the matrix with which VLA-6 interacts is currently unknown.

scholarly journals Uremic platelets have a functional defect affecting the interaction of von Willebrand factor with glycoprotein IIb-IIIa

Blood ◽  
1990 ◽  
Vol 76 (7) ◽  
pp. 1336-1340 ◽  
Author(s):  
G Escolar ◽  
A Cases ◽  
E Bastida ◽  
M Garrido ◽  
J Lopez ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Indirect Evidence ◽  
Flow Conditions ◽  
Experimental Conditions ◽  
Shear Rates ◽  
Functional Defect ◽  
Uremic Patients ◽  
Von Willebrand ◽  
Willebrand Factor

Uremic patients have an impaired platelet function that has been related to membrane glycoprotein (GP) abnormalities. Using a perfusion system, we have studied the interaction of normal and uremic platelets with vessel subendothelium (SE) under flow conditions. Reconstituted blood containing washed platelets, purified von Willebrand factor (vWF) (1 U/mL), and normal washed red blood cells was exposed to de- endothelialized rabbit segments for 10 minutes at two different shear rates (800 and 1,600 seconds-1). In some experiments a monoclonal antibody to the GPIIb-IIIa complex (EDU3) was added to the perfusates. With normal platelets, the percentage of the vessel covered by platelets (%CS) was 23.1% +/- 3.7% at 800 seconds-1 and 30% +/- 4.3% at 1,600 seconds-1. Platelets were observed in contact or forming monolayers on vessel SE. EDU3 inhibited the spreading of normal platelets. The %CS (11.1% +/- 3.3%) was statistically decreased (P less than .01) and most of the platelets were observed in contact with the vessel surface. These data indicate that, under flow conditions, the interaction of vWF with GPIIb-IIIa can support the spreading of normal platelets in the absence of exogenous fibrinogen. Under the same experimental conditions, the interaction of uremic platelets with SE was markedly impaired at both shear rates studied (P less than .01 v normal platelets). The presence of EDU3 did not modify the interaction of uremic platelets. These results confirm the impairment of the platelet adhesion observed in uremic patients. Furthermore, they indicate the presence of a functional defect in the interaction of vWF with GPIIb-IIIa. The fact that perfusions with normal and uremic platelets in the presence of an antibody to the GPIIb-IIIa complex did not show any differences gives indirect evidence on a functionally normal interaction vWF/GPIb in uremic patients.

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.

scholarly journals Platelet adhesion to laminin: role of Ca2+ and Mg2+ ions, shear rate, and platelet membrane glycoproteins

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 928-935 ◽  
Author(s):  
G Hindriks ◽  
MJ Ijsseldijk ◽  
A Sonnenberg ◽  
JJ Sixma ◽  
PG de Groot
Keyword(s):  
Shear Rate ◽  
Platelet Adhesion ◽  
Divalent Cations ◽  
Platelet Membrane ◽  
Flow Conditions ◽  
Membrane Glycoproteins ◽  
Shear Rates ◽  
The Matrix ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The adhesion of platelets to purified laminin under flow conditions was investigated. Adhesion to laminin was strongly dependent on the presence of divalent cations. In the absence of cations platelet adhesion (8% coverage in 5 minutes) was maximal at a shear rate of 100/s and no adhesion could be detected at shear rates above 800/s. In the presence of 0.8 mmol/L Mg2+ and 2 mmol/L Ca2+ platelet adhesion reached its maximum (30% coverage) around 800/s. At 1,800/s platelets still adhered to purified laminin (coverage of 6%). Antibodies against the E8 domain of laminin and antibodies against the alpha 6 and beta 1 chains of platelet membrane glycoprotein very late activation antigen-6 (VLA-6), completely inhibited adhesion. No inhibition was found with antibodies against glycoprotein IIb:IIIa, against the alpha 2 chain of VLA-2, and against the alpha 5 chain of VLA-5. Fibronectin and von Willebrand factor were not involved in laminin-dependent adhesion. Anti- VLA-6 partly inhibited platelet adhesion to the extracellular matrix of endothelial cells at shear rates below 800/s. Preincubation of the matrices with antilaminin E8 antibodies did not influence the adhesion. These results show that purified laminin supports platelet adhesion and that the presence of VLA-6 is important for platelet adhesion under flow conditions. The protein in the matrix with which VLA-6 interacts is currently unknown.

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