Comparison between Human Umbilical Artery and Rabbit Abdominal Aorta as Substrata for Platelet Adhesion and Platelet Thrombus Formation under Flow Conditions

1991 ◽  
Vol 28 (6) ◽  
pp. 520-531
Author(s):  
Ginés Escolar ◽  
Marta Garrido ◽  
José Aznar-Salatti ◽  
Antonio Ordinas ◽  
Eva Bastida
Keyword(s):  
Abdominal Aorta ◽  
Platelet Adhesion ◽  
Umbilical Artery ◽  
Thrombus Formation ◽  
Flow Conditions ◽  
Human Umbilical Artery ◽  
Platelet Thrombus

FIBRONECTIN IS REQUIRED FOR PLATELET ADHESION AND FOR THROMBUS FORMATION ON SUBENDOTHELIUM AND COLLAGEN SURFACES

1987 ◽  
Author(s):  
E Bastida ◽  
G Escolar ◽  
R Castillo ◽  
A Ordinas ◽  
J J Sixma
Keyword(s):  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Fibrillar Collagen ◽  
Flow Conditions ◽  
Shear Rates ◽  
Human Collagen ◽  
Platelet Thrombus ◽  
Computerized System ◽  
Total Coverage

Fibronectin (FN) plays a role in several adhesion mediated functions including the interaction of platelets with subendothelium.We investigated the role of plasma FN in platelet adhesion and platelet thrombus formation under flow conditions.To do this we used two different perfusion models:1)the annular chamber with α -chymotrypsin-treated rabbit vessel segments and 2)the flat chamber with coverslips coated with fibrillar purified human collagen type III.Perfusates consisted of washed platelets, and washed red blood celIs,suspended in normal or FN-depleted plasma.Perfusions were carried out for 10 min at shear rates of 300 or 1300 sec™1 Platelet deposition and thrombus dimensions were morphometrically evaluated by a computerized system. We found that depletion of plasma FN significantly reduced the percentage of total coverage surface and percentage of platelet thrombus, at both shear rates studied, and in both perfusion systems (p < 0.01)(p < 0.01).The dimensions of the platelet thrombi formed in perfusions at high shear rate were also significantly reduced in perfusions carried out with FN-depleted plasma.(p < 0.01). Addition of purified FN to FN-depleted perfusates restored all the values to those measured in the control perfusions.These results indicate that, in addition to supporting platelet adhesion to the subendothelium and to fibrillar collagen, FN contributes to platelet thrombus formation under flow conditions.

scholarly journals Fibronectin is required for platelet adhesion and for thrombus formation on subendothelium and collagen surfaces

Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1437-1442 ◽  
Author(s):  
E Bastida ◽  
G Escolar ◽  
A Ordinas ◽  
JJ Sixma
Keyword(s):  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Flow Conditions ◽  
Shear Rates ◽  
Platelet Aggregate ◽  
Human Collagen ◽  
Platelet Thrombus ◽  
Computerized System ◽  
Total Coverage

Abstract Fibronectin (FN) plays a role in several adhesion mediated functions including the interaction of platelets with subendothelium. We investigated the role of plasma FN in platelet adhesion and platelet thrombus formation under flow conditions. We used two different perfusion models: the annular chamber with alpha-chymotrypsin-treated rabbit vessel segments, and the flat chamber with coverslips coated with fibrillar purified human collagen type III. Perfusates consisted of washed platelets and washed RBCs, suspended in normal or FN-depleted plasma. Perfusions were carried out for ten minutes at shear rates of 300 or 1,300 s-1. Platelet deposition and thrombus dimensions were evaluated morphometrically by a computerized system. We found that depletion of plasma fibronectin significantly reduced the percentage of total coverage surface and percentage of platelet thrombus, at both shear rates studied, and in both perfusion systems (P less than .01) (P less than .01). The dimensions of the platelet thrombi formed in perfusions at high shear rate were also significantly reduced in perfusions carried out with FN depleted plasma (P less than .01). Addition of purified FN to FN-depleted perfusates restored all values to those measured in the control perfusions. These results indicate that plasma FN is required for platelet aggregate and thrombus formation following adhesion under flow conditions.

Increased Platelet Thrombus Formation Under Flow Condition In Myeloproliferative Neoplasms (MPN)

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 33-33
Author(s):  
Alfonso Vignoli ◽  
Paola van der Meijden ◽  
Marina Marchetti ◽  
Cinzia Giaccherini ◽  
Serena Tessarolo ◽  
...  
Keyword(s):  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Annexin V ◽  
Fluorescence Microscope ◽  
Control Group ◽  
Flow Conditions ◽  
Jak2 Mutation ◽  
Platelet Surface ◽  
Thrombotic Risk ◽  
Platelet Thrombus

Abstract Background Essential Thrombocythemia (ET) and Polycythemia Vera (PV) are MPNs characterized by a high incidence of both arterial and venous thrombosis, and microcirculatory disturbances. Platelet abnormalities have been variably involved in the thrombotic diathesis of these patients, without providing conclusive evidence. Remarkably, no studies have explored so far the MPN platelet thrombus formation capacity underflow conditions. Aim In order to evaluate whether and to what extent the MPN platelet membrane abnormalities may influence their interactions with the vessel wall components in a dynamic system, we wanted to characterize the ET and PV platelet adhesion capacity under flow conditions, by using an in vitro system based on a parallel flow chamber connected to the EVOS fluorescence microscope. The effects of the V617F JAK2 mutational status, cytoreductive therapy, and circulating von Willebrand Factor (vWF) on platelet adhesion in this system were also explored. Methods Nine ET (3M/6F; age 63 years, range 60-81) and 6 PV (3M/4F; age 74 years, range 58-82) patients were enrolled into the study upon informed consent. Eleven healthy subjects (5M/6F; age 44 years, range 35-55) acted as a control group (CTR). Peripheral venous whole blood was withdrawn in sodium citrate, recalcified in the presence of heparin, and perfused over a collagen-coated surface for 4 min at a shear rate of 1000 s-1. Platelets were then stained with an anti-CD62P (P-selectin)-FITC antibody as a platelet activation index, and annexin V-AlexaFluor647 as a measure of the procoagulant phosphatidylserine (PS) expression. After staining, images of adherent platelets in random fields were taken using phase contrast and fluorescence imaging with the EVOS fluorescence microscope system. Results were the mean±SD of the percentage of area covered by all platelets, or as the % of adherent platelets positive to either P-selectin or annexin V. In parallel, plasma vWF antigen and activity levels were measured by ELISA. Statistical analysis was performed by SPSS software package. Results Platelet adhesion was significantly greater (p<0.05) in both ET (49.3±14.5%) and PV patients (55.3±12.7%) compared to controls (31.6±7.3%). Among patients, platelet adhesion was significantly (p<0.05) increased in those positive for the V617F JAK2 mutation compared to the negative ones, with the highest values in the homozygous subjects. Patients on hydroxyurea (HU) therapy (n=7) had significantly lower platelet adhesion (45.2±13.0%) compared to non-HU-treated patients (56.9±10.4%; p<0.05).The % platelet adhesion directly related to either platelet (r=0.623, p=0.001) and leukocyte (r=0.506, p<0.01) counts, but not to plasma vWF levels. Multivariate regression analysis adjusted for age, sex, and HU therapy, confirmed platelet count and V617F JAK2 mutation as significant determinants of platelet adhesion. Although adhesion was increased, the platelet surface expression of P-selectin and PS was reduced in ET (P-sel: 70±11% pos. platelets; PS: 11±6% pos. platelets) and PV (P-sel: 66±13%; PS: 9±5%) patients compared to controls (P-sel: 74±8%; PS: 20±8%). Conclusions The data show for the first time, in MPN patients, an increased platelet adhesion capacity to collagen under flow conditions, indicating a greater thrombus formation potential. This phenomenon is likely not related to the expression of membrane P-selectin and phosphatidylserine, but is significantly influenced by the V617F JAK2 mutation burden and is sensitive to the cytoreductive treatment with HU. Prospective studies are worth to establish the role of the EVOS assay in assessing the levels of thrombotic risk in MPN patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Fibronectin is required for platelet adhesion and for thrombus formation on subendothelium and collagen surfaces

Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1437-1442
Author(s):  
E Bastida ◽  
G Escolar ◽  
A Ordinas ◽  
JJ Sixma
Keyword(s):  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Flow Conditions ◽  
Shear Rates ◽  
Platelet Aggregate ◽  
Human Collagen ◽  
Platelet Thrombus ◽  
Computerized System ◽  
Total Coverage

Fibronectin (FN) plays a role in several adhesion mediated functions including the interaction of platelets with subendothelium. We investigated the role of plasma FN in platelet adhesion and platelet thrombus formation under flow conditions. We used two different perfusion models: the annular chamber with alpha-chymotrypsin-treated rabbit vessel segments, and the flat chamber with coverslips coated with fibrillar purified human collagen type III. Perfusates consisted of washed platelets and washed RBCs, suspended in normal or FN-depleted plasma. Perfusions were carried out for ten minutes at shear rates of 300 or 1,300 s-1. Platelet deposition and thrombus dimensions were evaluated morphometrically by a computerized system. We found that depletion of plasma fibronectin significantly reduced the percentage of total coverage surface and percentage of platelet thrombus, at both shear rates studied, and in both perfusion systems (P less than .01) (P less than .01). The dimensions of the platelet thrombi formed in perfusions at high shear rate were also significantly reduced in perfusions carried out with FN depleted plasma (P less than .01). Addition of purified FN to FN-depleted perfusates restored all values to those measured in the control perfusions. These results indicate that plasma FN is required for platelet aggregate and thrombus formation following adhesion under flow conditions.

Absence of Fibrinogen in Afibrinogenemia Results in Large but Loosely Packed Thrombi under Flow Conditions

2001 ◽  
Vol 85 (04) ◽  
pp. 736-742 ◽  
Author(s):  
Ya-Ping Wu ◽  
Martin IJsseldijk ◽  
Jaap Zwaginga ◽  
Jan Sixma ◽  
Philip de Groot ◽  
...  
Keyword(s):  
Morphological Analysis ◽  
Surface Coverage ◽  
Thrombus Formation ◽  
Flow Conditions ◽  
Thrombotic Complications ◽  
Platelet Thrombus ◽  
The Difference ◽  
Adhesive Proteins ◽  
Lamellipodia Formation

SummaryWe studied the role of fibrinogen in platelet thrombus formation under flow on adhesive proteins using afibrinogenemic blood (LMWH anticoagulated) in a perfusion system. Perfusions with afibrinogenemic blood showed strong increased surface coverage and thrombus volume that normalized upon addition of fibrinogen. Similar studies using citrate anticoagulated blood showed that this was due to fibrinogen and not fibrin. Morphological analysis showed that afibrinogenemic thrombi were loosely packed and consisted mainly of dendritic platelets that contacted one another through filopodia. However, in the presence of fibrinogen, platelets formed lamellipodia and spread out on top of one another. Studies with radiolabeled platelets showed similar numbers of platelets in both conditions demonstrating that the difference is one of packing and the larger size is due to absence of lamellipodia formation and spreading. The found increased thrombus size and loosely packed platelets might help to understand thrombotic complications sometimes seen in afibrinogenemia patients.

The contributions of the α2β1 integrin to vascular thrombosis in vivo

Blood ◽  
2003 ◽  
Vol 102 (10) ◽  
pp. 3652-3657 ◽  
Author(s):  
Li He ◽  
Loretta K. Pappan ◽  
David G. Grenache ◽  
Zhengzhi Li ◽  
Douglas M. Tollefsen ◽  
...  
Keyword(s):  
Vascular Injury ◽  
Vessel Wall ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Critical Role ◽  
Flow Conditions ◽  
In Vivo Models ◽  
Vascular Thrombosis ◽  
Α2β1 Integrin

AbstractThe α2β1 integrin serves as a receptor for collagens, laminin, and several other nonmatrix ligands. Many studies have suggested that the α2β1 integrin is a critical mediator of platelet adhesion to collagen within the vessel wall after vascular injury and that the interactions of the platelet α2β1 integrin with subendothelial collagen after vascular injury are required for proper hemostasis. We have used the α2β1 integrin-deficient mouse to evaluate the contributions of the α2β1 integrin in 2 in vivo models of thrombosis. Studies using a model of endothelial injury to the carotid artery reveal that the α2β1 integrin plays a critical role in vascular thrombosis at the blood-vessel wall interface under flow conditions. In contrast, the α2β1 integrin is not required for the formation of thrombi and pulmonary emboli following intravascular injection of collagen. Our results are the first to document a critical in vivo role for the α2β1 integrin in thrombus formation at the vessel wall under conditions of shear following vascular injury. (Blood. 2003;102:3652-3657)

Identification of a Binding Site for Integrin αIIbβ3 in the von Willebrand factor (VWF) A1 Domain: Dual Roles for the A1 Domain in Platelet Thrombus Formation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3658-3658
Author(s):  
Junmei Chen ◽  
Miguel A. Cruz ◽  
José A. López
Keyword(s):  
Binding Site ◽  
Binding Sites ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Shear Stresses ◽  
Platelet Surface ◽  
Rgd Sequence ◽  
Platelet Thrombus ◽  
A1 Domain ◽  
Von Willebrand

Abstract In 1999, Wu et al found that blood from patients with type 3 von Willebrand disease (lacking VWF in both plasma and platelets) could not form thrombi on a collagen surface (Arterioscler. Thromb. Vasc Biol2000, 201661–1667). This suggested that VWF was absolutely required for the accumulation of platelets in thrombi under flow, even in the presence of fibrinogen. Platelets have two VWF receptors, the GP Ib-IX-V complexes and αIIbβ3 , the former mediating the initial tethering and attachment of platelets onto VWF and the latter being involved in platelet-platelet contacts. GP Ib-IX-V binds VWF within the A1 domain and αIIbβ3 is known to bind an Arg-Gly-Asp (RGD) sequence in the C1 domain. In the study of Wu et al, reconstitution of the VWF-deficient plasma with recombinant VWF missing the A1 domain failed to restore thrombus formation, even when the collagen surface was first coated with wild-type VWF to allow platelet attachment. The A1 domain is thus important not only for initial platelet adhesion but also for thrombus accumulation, possibly by binding another platelet receptor. Consistent with this, the number of binding sites for the isolated A1 domain on the platelet surface is more than twice the number of GP Ibα polypeptides. The receptor responsible for these binding sites is unknown but αIIbβ3 is a good candidate given its high copy number and the marked defect seen in platelet thrombus formation in its absence or blockade. Of interest, while deletion of A1 prevented thrombus formation in the studies of Wu et al, mutation of the VWF RGD sequence did not. We therefore examined whether αIIbβ3 also binds within the VWF A1 domain. We found the following. 1) Purified, unactivated αIIbβ3 binds to immobilized A1 domain, binding blocked by antibodies to either αIIbβ3 or A1. 2) Unactivated αIIbβ3 does not interact with immobilized full-length VWF, but binds VWF in the presence of ristocetin. The binding of αIIbβ3 to both VWF and isolated A1 is blocked by the αIIbβ3 antibody c7E3 but not by RGD peptides, and by the A1 antibody 6G1. This suggests that the αIIbβ3 binding site in the A1 domain may overlap the 6G1 epitope (residues 700-709), which is distinct from the GPIbα binding site. 3) 6G1 inhibits shear-induced platelet aggregation—a process that requires both GP Ibα and αIIbβ3—without blocking GP Ibα binding. 4) Platelets firmly adhere on the surface containing A1 and cross-linked collagen-related peptide (CRP), a potent GP VI agonist, at high shear stresses. The CRP-GP VI interaction is not strong enough to arrest platelets under flow, suggesting that GP VI signals could activate αIIbβ3, and αIIbβ3 could mediate firm adhesion. Consistent with this, the αIIbβ3 antibody c7E3 prevented firm platelet adhesion. In summary, we find that αIIbβ3 binds to the A1 domain, in or near the sequence of Glu700-Asp709. In addition to its apparent role in platelet-platelet interactions during thrombus growth, the binding of αIIbβ3 to the VWF A1 domain may also facilitate the binding of GP Ibα to a distinct region of A1, as the site of αIIbβ3 overlaps the binding site of ristocetin and 6G1, both which induce VWF to bind GP Ibα. Therefore, by binding to the same site as 6G1 and ristocetin in the C-terminal peptide of A1, αIIbβ3 may regulate the affinity of A1 for GP Ibα in flowing blood.

Sign in / Sign up

Export Citation Format

Share Document