scholarly journals Age-Associated Increase in Thrombogenicity and Its Correlation with von Willebrand Factor

2021 ◽  
Vol 10 (18) ◽  
pp. 4190
Author(s):  
Parnian Alavi ◽  
Abhisha M. Rathod ◽  
Nadia Jahroudi

Endothelial cells that cover the lumen of all blood vessels have the inherent capacity to express both pro and anticoagulant molecules. However, under normal physiological condition, they generally function to maintain a non-thrombogenic surface for unobstructed blood flow. In response to injury, certain stimuli, or as a result of dysfunction, endothelial cells release a highly adhesive procoagulant protein, von Willebrand factor (VWF), which plays a central role in formation of platelet aggregates and thrombus generation. Since VWF expression is highly restricted to endothelial cells, regulation of its levels is among the most important functions of endothelial cells for maintaining hemostasis. However, with aging, there is a significant increase in VWF levels, which is concomitant with a significant rise in thrombotic events. It is not yet clear why and how aging results in increased VWF levels. In this review, we have aimed to discuss the age-related increase in VWF, its potential mechanisms, and associated coagulopathies as probable consequences.

Blood ◽  
2014 ◽  
Vol 124 (10) ◽  
pp. 1669-1676 ◽  
Author(s):  
Jorien Claes ◽  
Thomas Vanassche ◽  
Marijke Peetermans ◽  
Laurens Liesenborghs ◽  
Christophe Vandenbriele ◽  
...  

Key PointsvWbp mediates adhesion of S aureus under flow to activated endothelial cells and the subendothelium via VWF. vWbp activates prothrombin and triggers the formation of bacteria–fibrin–platelet aggregates, which enhance adhesion to vessels under flow.


2018 ◽  
Vol 182 (1) ◽  
pp. 93-105 ◽  
Author(s):  
Ferdows Atiq ◽  
Karina Meijer ◽  
Jeroen Eikenboom ◽  
Karin Fijnvandraat ◽  
Eveline P. Mauser-Bunschoten ◽  
...  

1992 ◽  
Vol 67 (04) ◽  
pp. 453-457 ◽  
Author(s):  
Raelene L Kinlough-Rathbone ◽  
Marian A Packham ◽  
Dennis W Perry ◽  
J Fraser Mustard ◽  
Marco Cattaneo

SummaryThe stability of platelet aggregates is influenced by the extent of the release of granule contents; if release is extensive and aggregation is prolonged, deaggregation is difficult to achieve. The relative importance of the contributions of released substances to aggregate stability are not known, although stable thrombin-induced aggregates form in platelet-rich plasma from patients with barely detectable plasma or platelet fibrinogen, and ADP stabilizes thrombin-induced aggregates of platelets from patients with delta storage pool deficiency which otherwise deaggregate more readily than normal platelets. We degranulated platelets with thrombin (0.9 U/ml caused greater than 90% loss of delta and alpha granule contents) and recovered them as individual platelets in fresh medium. The degranulated platelets were reaggregated by thrombin (2 U/ml). To prevent continuing effects of thrombin, FPRCH2C1 was added when thrombin-induced aggregation of thrombin-degranulated platelets reached its maximum. EDTA (5 mM) or EGTA (5 mM) added at maximum aggregation did not deaggregate these platelets, indicating that the stability of these aggregates does not depend on Ca2+ in the medium. Whereas with control platelets a combination of PGE1 (10 μM) and chymotrypsin(10 U/ml) was required for deaggregation, with thrombin-degranulated platelets either PGE1 or chymo-trypsin alone caused extensive deaggregation. The rate and extent of deaggregation of thrombin-degranulated platelets by a combination of PGE1 and chymotrypsin was greater than with control platelets.Electron microscope gold immunocytochemistry using antihuman fibrinogen IgG, anti-von Willebrand factor and anti-fibronectin showed a) that fibrinogen in the vacuoles of degranulated platelets was visible at focal points of platelet contact in the aggregates, but that large areas of platelet contact had no fibrinogen detectable between them; and b) in comparison to fibrinogen, little fibronectin or von Willebrand factor (vWf) was detectable in the platelets.Since the linkages between thrombin-degranulated platelets reaggregated by thrombin can be disrupted either by raising cAMP (thus making glycoprotein IIb/IIIa unavailable) or by proteolysis, these linkages are less stable than those formed between normal platelets. It might therefore be expected that platelets that take part in thrombus formation and then recirculate are likely to form less stable thrombi than platelets that have not released their granule contents.


1993 ◽  
Vol 70 (06) ◽  
pp. 1053-1057 ◽  
Author(s):  
Agnès M Journet ◽  
Simin Saffaripour ◽  
Denisa D Wagner

SummaryBiosynthesis of the adhesive glycoprotein von Willebrand factor (vWf) by endothelial cells results in constitutive secretion of small multimers and storage of the largest multimers in rodshaped granules called Weibel-Palade bodies. This pattern is reproduced by expression of pro-vWf in heterologous cells with a regulated pathway of secretion, that store the recombinant protein in similar elongated granules. In these cells, deletion of the vWf prosequence prevents vWf storage. The prosequence, composed of two homologous domains (D1 and D2), actively participates in vWf multimer formation as well. We expressed deletion mutants lacking either the D1 domain (D2vWf) or the D2 domain (D1vWf) in various cell lines to analyze the relative importance of each domain in vWf muitimerization and storage. Both proteins were secreted efficiently without being retained in the endoplasmic reticulum. Despite this, neither multimerized past the dimer stage and they were not stored. We conclude that several segments of the prosequence are jointly involved in vWf muitimerization and storage.


1993 ◽  
Vol 70 (04) ◽  
pp. 707-711 ◽  
Author(s):  
Andrew D Blann ◽  
Charles N McCollum

SummaryThe effect of smoking on the blood vessel intima was examined by comparing indices of endothelial activity in serum from smokers with that from non-smokers. Serum from smokers contained higher levels of von Willebrand factor (p <0.01), the smoking markers cotinine (p <0.02) and thiocyanate (p <0.01), and was more cytotoxic to endothelial cells in vitro (p <0.02) than serum from non-smokers. The acute effects of smoking two unfiltered medium tar cigarettes was to briefly increase von Willebrand factor (p <0.001) and cytotoxicity of serum to endothelial cells in vitro (p <0.005), but lipid peroxides or thiocyanate were not increased by this short exposure to tobacco smoke. Although there were correlations between von Willebrand factor and smokers consumption of cigarettes (r = 0.28, p <0.02), number of years smoking (r = 0.41, p <0.001) and cotinine (r = 0.45, p <0.01), the tissue culture of endothelial cells with physiological levels of thiocyanate or nicotine suggested that these two smoking markers were not cytotoxic. They are therefore unlikely to be directly responsible for increased von Willebrand factor in the serum of smokers. We suggest that smoking exerts a deleterious influence on the endothelium and that the mechanism is complex.


1997 ◽  
Vol 77 (06) ◽  
pp. 1182-1188 ◽  
Author(s):  
Ulrich M Vischer ◽  
Claes B Wollheinn

Summaryvon Willebrand factor (vWf) is released from endothelial cell storage granules after stimulation with thrombin, histamine and several other agents that induce an increase in cytosolic free calcium ([Ca2+]i). In vivo, epinephrine and the vasopressin analog DDAVP increase vWf plasma levels, although they are thought not to induce vWf release from endothelial cells in vitro. Since these agents act via a cAMP-dependent pathway in responsive cells, we examined the role of cAMP in vWf secretion from cultured human umbilical vein endothelial cells. vWf release increased by 50% in response to forskolin, which activates adenylate cyclase. The response to forskolin was much stronger when cAMP degradation was blocked with IBMX, an inhibitor of phosphodiesterases (+200%), whereas IBMX alone had no effect. vWf release could also be induced by the cAMP analogs dibutyryl-cAMP (+40%) and 8-bromo-cAMP (+25%); although their effect was weak, they clearly potentiated the response to thrombin. Epinephrine (together with IBMX) caused a small, dose-dependent increase in vWf release, maximal at 10-6 M (+50%), and also potentiated the response to thrombin. This effect is mediated by adenylate cyclase-coupled β-adrenergic receptors, since it is inhibited by propranolol and mimicked by isoproterenol. In contrast to thrombin, neither forskolin nor epinephrine caused an increase in [Ca2+]j as measured by fura-2 fluorescence. In addition, the effects of forskolin and thrombin were additive, suggesting that they act through distinct signaling pathways. We found a close correlation between cellular cAMP content and vWf release after stimulation with epinephrine and forskolin. These results demonstrate that cAMP-dependent signaling events are involved in the control of exocytosis from endothelial cells (an effect not mediated by an increase in [Ca2+]i) and provide an explanation for epinephrine-induced vWf release.


1987 ◽  
Author(s):  
C L Verweij ◽  
M Hart ◽  
H Pannekoek

The von Willebrand factor (vWF) is a multimeric plasma glycoprotein synthesized in vascular endothelial cells as a pre-pro-polypeptide with a highly repetitive domain structure, symbolized by the formula:(H)-D1-D2-D'-D3-A1-A2-A3-D4-B1-B2-B3-C1-C2-(0H).A heterologous expression system, consisting of a monkey kidney cell line (C0S-1), transfected with full-length vWF cDNA, is shown to mimic the constitutively, secretory pathway of vWF in endothelial cells. The assembly of pro-vWF into multimers and the proteolytic processing of these structures is found to oro-ceed along the following, consecutive steps. Pro-vWF subunits associate to form dimers, a process that does not involve the pro-polypeptide of pro-vWF. This observation is derived from transfection of C0S-1 cells with vWF cDNA, lacking the genetic information encoding the pro-polypeptide, composed of the domains D1 and D2. Pro-vWF dimers are linked intracellularly to form a regular series of multimeric structures that are secreted and cannot be distinguished from those released constitutively by endothelial cells. The presence of the pro-polypeptide, embedded in pro-vWF, is obligatory for multimerization since the deletion mutant lacking the D1 and D2 domains fails to assemble beyond the dimer stage. It is argued that the D domains are involved in interchain interactions.


Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1531-1534 ◽  
Author(s):  
LA Sporn ◽  
VJ Marder ◽  
DD Wagner

Abstract Large multimers of von Willebrand factor (vWf) are released from the Weibel-Palade bodies of cultured endothelial cells following treatment with a secretagogue (Sporn et al, Cell 46:185, 1986). These multimers were shown by immunofluorescent staining to bind more extensively to the extracellular matrix of human foreskin fibroblasts than constitutively secreted vWf, which is composed predominantly of dimeric molecules. Increased binding of A23187-released vWf was not due to another component present in the releasate, since releasate from which vWf was adsorbed, when added together with constitutively secreted vWf, did not promote binding. When iodinated plasma vWf was overlaid onto the fibroblasts, the large forms bound preferentially to the matrix. These results indicated that the enhanced binding of the vWf released from the Weibel-Palade bodies was likely due to its large multimeric size. It appears that multivalency is an important component of vWf interaction with the extracellular matrix, just as has been shown for vWf interaction with platelets. The pool of vWf contained within the Weibel-Palade bodies, therefore, is not only especially suited for platelet binding, but also for interaction with the extracellular matrix.


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