Role of Heparin in Tumor Cell-Induced Platelet Aggregation

1986 ◽  
Vol 56 (01) ◽  
pp. 090-094 ◽  
Author(s):  
Kazuo Yamamoto ◽  
Hisayo Kitagawa ◽  
Kenjiro Tanoue ◽  
Takashi Tsuruo ◽  
Naomasa Yamamoto ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Von Willebrand Factor ◽  
Induce Platelet Aggregation ◽  
Platelet Suspension ◽  
B16f10 Cells ◽  
Von Willebrand ◽  
Induced Aggregation ◽  
Willebrand Factor

SummaryB16 mouse melanoma cell lines (B16F1, B16F10 and B16BL6) were able to induce platelet aggregation, and concomitant release of ATP in heparinized platelet-rich plasma (PRP). In citrated PRP, these tumor cells did not induce platelet aggregation. Addition of heparin to citrated PRP enabled these tumor cells to induce aggregation. In heparinized PRP, platelet aggregates induced by B16F10 cells were dissociated by the addition of either 4 mM EDTA, 10 mM CaCl2 or 0.1 μg/ml protamine sulfate. B16F10-induced aggregation in heparinized PRP was inhibited by preincubation with anti-fibronectin antibody, but not with antifibrinogen or anti-von Willebrand factor antibodies. B16F10 cells induced aggregation in washed platelet suspension with the addition of heparinized platelet-poor plasma (PPP). Cryoprecipi-tate from human plasma showed the same effect in the presence of heparin if substituted for PPP. The mixture of purified fibronectin, von Willebrand factor, fibrinogen and heparin were less effective than cryoprecipitate on B16F10-induced aggregation of washed platelets. The results suggest that an interaction between fibronectin and heparin may be important in tumor cell-induced aggregation.

scholarly journals New Method for Assessment of Plasma Von Willebrand Factor

1977 ◽  
Author(s):  
T. Sano ◽  
T. Motomiya ◽  
N. Mashimo ◽  
H. Yamazaki
Keyword(s):  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Platelet Rich Plasma ◽  
Normal Subjects ◽  
Induce Platelet Aggregation ◽  
Platelet Suspension ◽  
Maximal Plasma ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Diabetes Melitus

As much interests have been focused on von Willebrand factor (vWF) in diabetes melitus and atherosclerosis, request to determine vWF has been increasing recently. Two methods for assessment of plasma vWF level, without platelet aggregometer, were devised. 1) Platelet-rich plasma (PRP) sensitivity to ristocetin-induced platelet aggregation (RIPA): PRP was separated without centrifugation from citrated blood. Serially two-fold diluted restocetin (16 to 16x2-10 mg/ml) was prepared in a Cooke Microtiter tray and PRP (25 μl each) was added to each concentration of ristocetin. Then the ristocetin-PRP mixture was agitated for 15 seconds using a Kowa Kizai Micromixer and the minimum effective final concentration of ristocetin to give platelet aggregation was obtained microscopically and this was defined as PRP sensitivity to RIPA. This method is convenient for screening test. 2) vWF assay:Serially two-fold diluted plasma (2 to 1024 times, in Tris-salin pH 7.2 containing 12 mg/ml bovine serum albumin), fixed and washed platelet suspension (6x105 /μl, Macfarlane et al.1975) and 3 mg/ml ristocetin were mixed (25 μl each) in a microtiter tray and agitated for 15 seconds. The maximal plasma dilution to induce platelet aggregation was obtained microscopically and defined as the titer of plasma vWF. In normal subjects, minimum effective ristocetin concentration (PRP sensitivity to RIPA) was around 1 to 0.5 mg/ml and maximal plasma dilution to give platelet aggregation (vWF titer) was around 16 to 32 times. The present methods have a good reproducibility and are performed easily without aggregometer and thought to be useful clinically.

THE PLATELET AGGREGATING PROPERTIES OF TYPE IIB VON WILLEBRAND FACTOR (vWF): THE ROLE OF PLATELET ACTIVATION, FIBRINOGEN AND TWO DISTINCT MEMBRANE RECEPTORS

1987 ◽  
Author(s):  
L De Marco ◽  
M Mazzucato ◽  
M G Del Ben ◽  
U Budde ◽  
A B Federici ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Binding Domain ◽  
Platelet Glycoprotein ◽  
Induce Platelet Aggregation ◽  
Adhesive Proteins ◽  
Von Willebrand ◽  
Induced Aggregation ◽  
Willebrand Factor

Three preparations of purified von Willebrand factor (vWF), obtained from unrelated patients affected by type IIB von Willebrand disease, were found to have normal sialic acid content (between 129-190 nmoles/mg of vWF, as compared to 158 ± 17 nmoles/mg in four normal preparations) and to induce platelet aggregation in the presence of physiologic levels of divalent cations and without addition of ristocetin. A monoclonal antibody that blocks the vWF binding domain of the platelet glycoprotein (GP) Ib caused complete inhibition of IIB vWF-induced aggregation. On the contrary, a monoclonal antibody that blocks the receptor for adhesive proteins on the platelet GPIIb/IIIa complex failed to inhibit the initial response of platelets to high concentration of IIB vWF Moreover, IIB vWF caused agglutination of formalin-fixed platelets that was blocked only by the anti-GPIb antibody, suggesting that the binding of vWF to GPIb, even in the absence of ristocetin, results in platelet-platelet interaction that is followed by exposure of the GPIIb/IIIa receptors for adhesive proteins. Endogenous ADP, normally active platelet metabolism and fibrinogen binding to GPIIb/IIIa were necessary for maximal and irreversible platelet aggregation. In the absence of fibrinogen, however, aggregation was mediated by vWF binding to GPIIb/IIIa. A 52/48 kDa tryptic fragment containing the GPIb binding domain of normal vWF completely blocked the aggregation induced by all three IIB vWF preparations. The present study defines in detail the mechanisms involved in IIB vWF-induced platelet aggregation. Moreover, it establishes that the GPIb binding domain of normal and IIB vWF are closely related and that desialylation is not required for the direct interaction of IIB vWF with GPIb.

scholarly journals Platelet Aggregation Induced by a Monoclonal Antibody to the A1 Domain of von Willebrand Factor

Blood ◽  
1998 ◽  
Vol 91 (10) ◽  
pp. 3792-3799 ◽  
Author(s):  
Hilde Depraetere ◽  
Nadine Ajzenberg ◽  
Jean-Pierre Girma ◽  
Catherine Lacombe ◽  
Dominique Meyer ◽  
...  
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Inhibitory Effect ◽  
Platelet Glycoprotein ◽  
Rotational Viscometer ◽  
Induce Platelet Aggregation ◽  
Static Conditions ◽  
Von Willebrand ◽  
Willebrand Factor

Shear-induced platelet aggregation (SIPA) involves von Willebrand Factor (vWF) binding to platelet glycoprotein (GP)Ib at high shear stress, followed by the activation of αIIbβ3. The purpose of this study was to determine the vWF sequences involved in SIPA by using monoclonal antibodies (MoAbs) to vWF known to interfere with its binding to GPIb and to αIIbβ3. Washed platelets were exposed to shear rates between 100 and 4,000 seconds−1 in a rotational viscometer. SIPA was quantitated by flow cytometry as the disappearance of single platelets (DSP) in the sheared sample in the presence of vWF, relative to a control in the absence of shear and vWF. At a shear rate of 4,000 seconds−1, DSP was increased from 5.9% ± 3.5% in the absence of vWF to 32.7% ± 6.3% in the presence of vWF. This increase in SIPA was not associated with an elevation of P-selectin expression. vWF-dependent SIPA was completely abolished by MoAb 6D1 to GPIb and partially inhibited by MoAb 10E5 to αIIbβ3. Three MoAbs to vWF were compared for their effect on SIPA at 4,000 seconds−1 in the presence of vWF: MoAb 328, known to block vWF binding to GPIb in the presence of ristocetin, MoAb 724 blocking vWF binding to GPIb in the presence of botrocetin, and MoAb 9, an inhibitor of vWF binding to αIIbβ3. Similar to the effect of MoAb 6D1, MoAb 328 completely inhibited the effect of vWF, whereas MoAb 9 had a partial inhibitory effect, as MoAb 10E5 did. In contrast, MoAb 724, as well as its F(ab′)2 fragments, promoted shear-dependent platelet aggregation (165% of the DSP value obtained in the absence of MoAb 724), indicating that MoAb 724 was responsible for an enhanced aggregation, which was independent of binding to the platelet Fcγ receptor. In addition, the enhancement of aggregation induced by MoAb 724 was abrogated by MoAb 6D1 or 10E5 to the level of SIPA obtained in the presence of vWF incubated with a control MoAb to vWF. Finally, the activating effect of MoAb 724 was also found under static conditions at ristocetin concentrations too low to induce platelet aggregation. Our results suggested that on binding to a botrocetin-binding site on vWF, MoAb 724 mimics the effect of botrocetin by inducing an active conformation of vWF that is more sensitive to shear stress or to low ristocetin concentration.

Von Willebrand Factor Antigen and Factor XI Activity Levels As Predictors of Bleeding Tendency in Israeli Patients with Von Willebrand's Disease

1995 ◽  
Vol 1 (4) ◽  
pp. 260-264 ◽  
Author(s):  
Benjamin Brenner ◽  
Tamar Stemberg ◽  
Arieh Laor ◽  
Shulamit Tavori ◽  
Ilana Tatarsky ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Activity Levels ◽  
Factor Xi ◽  
Factor Xi Deficiency ◽  
Von Willebrand Factor Antigen ◽  
Von Willebrand ◽  
Induced Aggregation ◽  
Willebrand Factor ◽  
Factor Antigen

Previous preliminary data and case reports have suggested an association of von Willebrand's disease (vWD) with factor XI deficiency and platelet abnormalities. We have analyzed the prevalence of factor XI deficiency and thrombocytopathy in a cohort of Israeli patients with vWD. Decreased factor XI levels (<67 U/dl) were documented in 35 of 63 (36%) vWD subjects; factor XI levels were <30 U/dl in five of 60 (8%). A significant decline in ADP-induced platelet aggregation (<30% of control) was found in 48% of vWD patients. Likewise, epinephrine-induced aggregation was reduced in 41%, and collagen-induced aggregation was decreased in 7% of vWD patients. Logistic regression analysis showed that while Ivy bleeding time, ristocetin cofactor, and ristocetin-induced platelet aggregation did not predict bleeding, both von Willebrand factor antigen and factor XI activity levels predict bleeding in patients with vWD. These findings suggest that mild factor XI deficiency and thrombocytopathy are common in Israeli subjects with vWD and that associated factor XI deficiency can result in clinical bleeding in these patients. Key Words: Von Willebrand' s disease—Factor XI deficiency—Thrombocytopathy.

scholarly journals Platelet Aggregation Induced by a Monoclonal Antibody to the A1 Domain of von Willebrand Factor

Blood ◽  
1998 ◽  
Vol 91 (10) ◽  
pp. 3792-3799 ◽  
Author(s):  
Hilde Depraetere ◽  
Nadine Ajzenberg ◽  
Jean-Pierre Girma ◽  
Catherine Lacombe ◽  
Dominique Meyer ◽  
...  
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Inhibitory Effect ◽  
Platelet Glycoprotein ◽  
Rotational Viscometer ◽  
Induce Platelet Aggregation ◽  
Static Conditions ◽  
Von Willebrand ◽  
Willebrand Factor

AbstractShear-induced platelet aggregation (SIPA) involves von Willebrand Factor (vWF) binding to platelet glycoprotein (GP)Ib at high shear stress, followed by the activation of αIIbβ3. The purpose of this study was to determine the vWF sequences involved in SIPA by using monoclonal antibodies (MoAbs) to vWF known to interfere with its binding to GPIb and to αIIbβ3. Washed platelets were exposed to shear rates between 100 and 4,000 seconds−1 in a rotational viscometer. SIPA was quantitated by flow cytometry as the disappearance of single platelets (DSP) in the sheared sample in the presence of vWF, relative to a control in the absence of shear and vWF. At a shear rate of 4,000 seconds−1, DSP was increased from 5.9% ± 3.5% in the absence of vWF to 32.7% ± 6.3% in the presence of vWF. This increase in SIPA was not associated with an elevation of P-selectin expression. vWF-dependent SIPA was completely abolished by MoAb 6D1 to GPIb and partially inhibited by MoAb 10E5 to αIIbβ3. Three MoAbs to vWF were compared for their effect on SIPA at 4,000 seconds−1 in the presence of vWF: MoAb 328, known to block vWF binding to GPIb in the presence of ristocetin, MoAb 724 blocking vWF binding to GPIb in the presence of botrocetin, and MoAb 9, an inhibitor of vWF binding to αIIbβ3. Similar to the effect of MoAb 6D1, MoAb 328 completely inhibited the effect of vWF, whereas MoAb 9 had a partial inhibitory effect, as MoAb 10E5 did. In contrast, MoAb 724, as well as its F(ab′)2 fragments, promoted shear-dependent platelet aggregation (165% of the DSP value obtained in the absence of MoAb 724), indicating that MoAb 724 was responsible for an enhanced aggregation, which was independent of binding to the platelet Fcγ receptor. In addition, the enhancement of aggregation induced by MoAb 724 was abrogated by MoAb 6D1 or 10E5 to the level of SIPA obtained in the presence of vWF incubated with a control MoAb to vWF. Finally, the activating effect of MoAb 724 was also found under static conditions at ristocetin concentrations too low to induce platelet aggregation. Our results suggested that on binding to a botrocetin-binding site on vWF, MoAb 724 mimics the effect of botrocetin by inducing an active conformation of vWF that is more sensitive to shear stress or to low ristocetin concentration.

Helicobacter pylori binds von Willebrand factor and interacts with GPIb to induce platelet aggregation

2003 ◽  
Vol 124 (7) ◽  
pp. 1846-1854 ◽  
Author(s):  
Michael F Byrne ◽  
Steven W Kerrigan ◽  
Paul A Corcoran ◽  
John C Atherton ◽  
Frank E Murray ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Induce Platelet Aggregation ◽  
Von Willebrand ◽  
Willebrand Factor

Emerging Roles for von Willebrand Factor in Cancer Cell Biology

2017 ◽  
Vol 44 (02) ◽  
pp. 159-166 ◽  
Author(s):  
Roger Preston ◽  
Tracy Robson ◽  
James O'Donnell ◽  
Jamie O'Sullivan
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Cancer Cell ◽  
Von Willebrand Factor ◽  
Cell Biology ◽  
Tumor Metastasis ◽  
Human Tumor ◽  
Advanced Tumor Stage ◽  
Von Willebrand ◽  
Willebrand Factor

Abstractvon Willebrand factor (VWF) is a complex multimeric plasma glycoprotein that plays critical roles in normal hemostasis. However, additional novel roles for VWF in modulating cancer cell biology, and in particular tumor metastasis, have recently been reported. Markedly elevated plasma VWF levels were associated with advanced tumor stage and metastatic disease. These observations have raised the question of whether VWF may be involved in regulating tumor progression. Interestingly, novel findings indicate that VWF is expressed by a variety of tumor cells of nonendothelial origin. Critically, tumor cells that exhibit de novo acquired VWF expression demonstrate enhanced binding to endothelial cells (EC) and platelets, and increased extravasation through EC barriers. Furthermore, in vitro studies have shown that VWF can bind a variety of different tumor cells mediated by specific receptors expressed on the tumor cell surface. The concept that VWF is important in modulating tumor metastasis is further supported by in vivo experiments demonstrating that antibody-mediated VWF inhibition significantly attenuated murine metastasis. Intriguingly, however, VWF binding to specific human tumor cell lines results in apoptosis. In this study, the authors provide an overview of recent advances supporting a role for VWF in regulating multiple aspects of cancer cell biology.

scholarly journals Shear-induced platelet aggregation requires von Willebrand factor and platelet membrane glycoproteins Ib and IIb-IIIa

Blood ◽  
1987 ◽  
Vol 69 (2) ◽  
pp. 625-628 ◽  
Author(s):  
DM Peterson ◽  
NA Stathopoulos ◽  
TD Giorgio ◽  
JD Hellums ◽  
JL Moake
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Platelet Rich Plasma ◽  
Shear Stresses ◽  
Membrane Glycoprotein ◽  
Membrane Glycoproteins ◽  
Von Willebrand ◽  
Induced Aggregation ◽  
Willebrand Factor

Different types of platelets in various types of plasma were subjected to levels of shear stress that produce irreversible platelet aggregation in normal platelet-rich plasma (PRP). At shear stresses of 90 or 180 dyne/cm2 applied for 30 seconds or five minutes, aggregation was either absent or only transient and reversible using severe von Willebrand's disease (vWD) PRP (less than 1% von Willebrand factor, vWF); Bernard-Soulier syndrome (BSS) PRP (platelets deficient in the membrane glycoprotein Ib, GPIb); normal PRP plus monoclonal antibody (MoAb) to GPIb; thrombasthenic PRP (platelets deficient in membrane glycoprotein IIb-IIIa complex, GPIIb-IIIa); and normal PRP plus MoAb to GPIIb-IIIa. Shear-induced aggregation was inhibited under the above conditions, even though the platelets were activated to release their granular contents. Sheared normal platelets in vWD plasma aggregated in response to added vWF. These studies demonstrate that the formation of stable platelet aggregates under conditions of high shear requires vWF and the availability of both GPIb and GPIIb-IIIa on platelet membranes. The experiments demonstrate that vWF-platelet interactions can occur in the absence of artificial agonists or chemical modification of vWF. They suggest a possible mechanism for platelet aggregation in stenosed or partially obstructed arterial vessels in which the platelets are subjected to relatively high levels of shear stress.

scholarly journals Shear-induced platelet aggregation requires von Willebrand factor and platelet membrane glycoproteins Ib and IIb-IIIa

Blood ◽  
1987 ◽  
Vol 69 (2) ◽  
pp. 625-628 ◽  
Author(s):  
DM Peterson ◽  
NA Stathopoulos ◽  
TD Giorgio ◽  
JD Hellums ◽  
JL Moake
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Platelet Rich Plasma ◽  
Shear Stresses ◽  
Membrane Glycoprotein ◽  
Membrane Glycoproteins ◽  
Von Willebrand ◽  
Induced Aggregation ◽  
Willebrand Factor

Abstract Different types of platelets in various types of plasma were subjected to levels of shear stress that produce irreversible platelet aggregation in normal platelet-rich plasma (PRP). At shear stresses of 90 or 180 dyne/cm2 applied for 30 seconds or five minutes, aggregation was either absent or only transient and reversible using severe von Willebrand's disease (vWD) PRP (less than 1% von Willebrand factor, vWF); Bernard-Soulier syndrome (BSS) PRP (platelets deficient in the membrane glycoprotein Ib, GPIb); normal PRP plus monoclonal antibody (MoAb) to GPIb; thrombasthenic PRP (platelets deficient in membrane glycoprotein IIb-IIIa complex, GPIIb-IIIa); and normal PRP plus MoAb to GPIIb-IIIa. Shear-induced aggregation was inhibited under the above conditions, even though the platelets were activated to release their granular contents. Sheared normal platelets in vWD plasma aggregated in response to added vWF. These studies demonstrate that the formation of stable platelet aggregates under conditions of high shear requires vWF and the availability of both GPIb and GPIIb-IIIa on platelet membranes. The experiments demonstrate that vWF-platelet interactions can occur in the absence of artificial agonists or chemical modification of vWF. They suggest a possible mechanism for platelet aggregation in stenosed or partially obstructed arterial vessels in which the platelets are subjected to relatively high levels of shear stress.

scholarly journals Shear stress-induced von Willebrand factor binding to platelet glycoprotein Ib initiates calcium influx associated with aggregation

Blood ◽  
1992 ◽  
Vol 80 (1) ◽  
pp. 113-120 ◽  
Author(s):  
TW Chow ◽  
JD Hellums ◽  
JL Moake ◽  
MH Kroll
Keyword(s):  
Monoclonal Antibody ◽  
Shear Stress ◽  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Fluid Shear Stress ◽  
Platelet Glycoprotein ◽  
Platelet Surface ◽  
Von Willebrand ◽  
Induced Aggregation ◽  
Willebrand Factor

Platelets subjected to elevated levels of fluid shear stress in the absence of exogenous agonists will aggregate. Shear stress-induced aggregation requires von Willebrand factor (vWF) multimers, extracellular calcium (Ca2+), adenosine diphosphate (ADP), and platelet membrane glycoprotein (GP)Ib and GPIIb-IIIa. The sequence of interaction of vWF multimers with platelet surface receptors and the effect of these interactions on platelet activation have not been determined. To elucidate the mechanism of shear stress-induced platelet aggregation, suspensions of washed platelets were subjected to different levels of uniform shear stress (15 to 120 dyne/cm2) in an optically modified cone and plate viscometer. Cytoplasmic ionized calcium ([Ca2+]i) and aggregation of platelets were monitored simultaneously during the application of shear stress; [Ca2+]i was measured using indo-1 loaded platelets and aggregation was measured as changes in light transmission. Basal [Ca2+]i was approximately 60 to 100 nmol/L. An increase of [Ca2+]i (up to greater than 1,000 nmol/L) was accompanied by synchronous aggregation, and both responses were dependent on the shear force and the presence of vWF multimers. EGTA chelation of extracellular Ca2+ completely inhibited vWF-mediated [Ca2+]i and aggregation responses to shear stress. Aurin tricarboxylic acid, which blocks the GPIb recognition site on the vWF monomer, and 6D1, a monoclonal antibody to GPIb, also completely inhibited platelet responses to shear stress. The tetrapeptide RGDS and the monoclonal antibody 10E5, which inhibit vWF binding to GPIIb-IIIa, partially inhibited shear stress-induced [Ca2+]i and aggregation responses. The combination of creatine phosphate/creatine phosphokinase, which converts ADP to adenosine triphosphate and blocks the effect of ADP released from stimulated platelets, inhibited shear stress-induced platelet aggregation without affecting the increase of [Ca2+]i. Neither the [Ca2+]i nor aggregation response to shear stress was inhibited by blocking platelet cyclooxygenase metabolism with acetylsalicylic acid. These results indicate that GPIb and extracellular Ca2+ are absolutely required for vWF-mediated [Ca2+]i and aggregation responses to imposed shear stress, and that the interaction of vWF multimers with GPIIb-IIIa potentiates these responses. Shear stress-induced elevation of platelet [Ca2+]i, but not aggregation, is independent of the effects of release ADP, and both responses occur independently of platelet cyclooxygenase metabolism. These results suggest that shear stress induces the binding of vWF multimers to platelet GPIb and this vWF-GPIb interaction causes an increase of [Ca2+]i and platelet aggregation, both of which are potentiated by vWF binding to the platelet GPIIb-IIIa complex.

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