In vivo Studies of von Willebrand Factor and Other Endothelial Molecules in Diabetic Microangiopathy

2015 ◽  
pp. 156-163 ◽  
Author(s):  
M. Porta ◽  
M. La Selva ◽  
P. Molinatti ◽  
G. M. Molinatti
Keyword(s):  
Von Willebrand Factor ◽  
In Vivo Studies ◽  
Diabetic Microangiopathy ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals Clearance of von Willebrand factor

2008 ◽  
Vol 99 (02) ◽  
pp. 271-278 ◽  
Author(s):  
Olivier D. Christophe ◽  
Beatrijs D. Oortwijn ◽  
Peter J. Lenting ◽  
Cécile V. Denis
Keyword(s):  
Von Willebrand Factor ◽  
Half Life ◽  
Von Willebrand Disease ◽  
In Vivo Studies ◽  
Missense Mutations ◽  
Common Component ◽  
Starting Point ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryThe life cycle of von Willebrand factor (VWF) comprises a number of distinct steps, ranging from the controlled expression of theVWF gene in endothelial cells and megakaryocytes to the removal of VWF from the circulation. The various aspects of VWF clearance have been the objects of intense research in the last few years, stimulated by observations thatVWF clearance is a relatively common component of the pathogenesis of type 1 von Willebrand disease (VWD). Moreover, improving the survival of VWF is now considered as a viable therapeutic strategy to prolong the half-life of factor VIII in order to optimise treatment of haemophilia A. The present review aims to provide an overview of recent findings with regard to the molecular basis of VWF clearance. A number of parameters have been identified that influence VWF clearance, including its glycosylation profile and a number of VWF missense mutations. In addition, in-vivo studies have been used to identify cells that contribute to the catabolism of VWF, providing a starting point for the identification of receptors that mediate the cellular uptake ofVWF.Finally, we discuss recent data describing chemically modification of VWF as an approach to prolong the half-life of the VWF/FVIII complex.

Abnormal Structure of von Willebrand Factor in Myeloproliferative Syndrome Is Associated to Either Thrombotic or Bleeding Diathesis

1987 ◽  
Vol 58 (02) ◽  
pp. 753-757 ◽  
Author(s):  
M F López-Fernández ◽  
C López-Berges ◽  
R Martín ◽  
A Pardo ◽  
F J Ramos ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Proteinase Inhibitors ◽  
Relative Proportion ◽  
Variable Degree ◽  
Bleeding Diathesis ◽  
Myeloproliferative Syndrome ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryThe multimeric and subunit patterns of plasma von Willebrand factor (vWF) were analyzed in eight patients with myeloproliferative syndrome (MS) in order to investigate the possible existence of heterogeneity in the “in vivo” proteolytic cleavage of the protein, previously observed in this entity. Six patients lacked large vWF multimers, five of them having normal bleeding times (BT) and clinically documented episodes of thrombotic origin, whereas one patient had long BT and bleeding symptoms. Seven patients showed a relative increase in the 176 kDa subunit fragment while the 189 kDa polypeptide was increased in only one. In addition, another patient (and prior to any therapy) showed the presence of a new fragment of approximately 95 kDa which disappeared after Busulfan therapy. The collection of blood from these patients with proteinase inhibitors did not correct the abnormalities.The infusion of DDAVP to two patients with abnormal vWF was accompanied by: the appearance of larger vWF multimers which disappeared rapidly from plasma; an increase in the relative proportion of the satellite bands of each multimer and a further increase of the 176 kDa fragment. These data point to some heterogeneity in the vWF abnormality present in MS which may be related in part to a variable degree of proteolysis of vWF occurring “in vivo” rather than “in vitro”, and which may be associated to either a thrombotic or a bleeding diathesis. They also suggest that despite the presence of abnormal, already proteolyzed vWF, DDAVP-enhanced proteolysis occurs in MS to a similar extent to what is described in normal individuals.

Epinephrine Induces von Willebrand Factor Release from Cultured Endothelial Cells: Involvement of Cyclic AMP-dependent Signalling in Exocytosis

1997 ◽  
Vol 77 (06) ◽  
pp. 1182-1188 ◽  
Author(s):  
Ulrich M Vischer ◽  
Claes B Wollheinn
Keyword(s):  
Endothelial Cells ◽  
Adenylate Cyclase ◽  
Von Willebrand Factor ◽  
Umbilical Vein ◽  
Free Calcium ◽  
Camp Content ◽  
Von Willebrand ◽  
Willebrand Factor

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.

Mouse models to study von Willebrand factor structure-function relationships in vivo

2009 ◽  
Vol 29 (01) ◽  
pp. 17-20 ◽  
Author(s):  
I. Marx ◽  
I. Badirou ◽  
R. Pendu ◽  
O. Christophe ◽  
C. V. Denis
Keyword(s):  
Structure Function ◽  
Transient Expression ◽  
Von Willebrand Factor ◽  
Large Size ◽  
Mouse Hepatocytes ◽  
Function Relationship ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryVon Willebrand factor (VWF) structure-function relationship has been studied only through in vitro approaches. The VWF-deficient mouse model has been extremely useful to examine the in vivo function of VWF but does not allow a more subtle analysis of the relative importance of its different domains. However, considering the large size of VWF and its capacity to interact with various ligands in order to support platelet adhesion and aggregation, the necessity to evaluate independently these interactions appeared increasingly crucial. A recently developed technique, known as hydrodynamic injection, which allows transient expression of a transgene by mouse hepatocytes, proved very useful in this regard. Indeed, transient expression of various VWF mutants in VWF-deficient mice contributed to improve our knowledge about the role of VWF interaction with subendothelial collagens and with platelets receptors in VWF roles in haemostasis and thrombosis. These findings can provide new leads in the development of anti-thrombotic therapies.

scholarly journals Molecular Characterization of the Von Willebrand Factor Type D Domain of Vitellogenin from Takifugu flavidus

Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 181
Author(s):  
Kun Qiao ◽  
Caiyun Jiang ◽  
Min Xu ◽  
Bei Chen ◽  
Wenhui Qiu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Von Willebrand Factor ◽  
Molecular Mechanisms ◽  
Protein Domain ◽  
Type D ◽  
Protein Toxin ◽  
Factor Type ◽  
Von Willebrand ◽  
Willebrand Factor

The von Willebrand factor type D (VWD) domain in vitellogenin has recently been found to bind tetrodotoxin. The way in which this protein domain associates with tetrodotoxin and participates in transporting tetrodotoxin in vivo remains unclear. A cDNA fragment of the vitellogenin gene containing the VWD domain from pufferfish (Takifugu flavidus) (TfVWD) was cloned. Using in silico structural and docking analyses of the predicted protein, we determined that key amino acids (namely, Val115, ASP116, Val117, and Lys122) in TfVWD mediate its binding to tetrodotoxin, which was supported by in vitro surface plasmon resonance analysis. Moreover, incubating recombinant rTfVWD together with tetrodotoxin attenuated its toxicity in vivo, further supporting protein–toxin binding and indicating associated toxicity-neutralizing effects. Finally, the expression profiling of TfVWD across different tissues and developmental stages indicated that its distribution patterns mirrored those of tetrodotoxin, suggesting that TfVWD may be involved in tetrodotoxin transport in pufferfish. For the first time, this study reveals the amino acids that mediate the binding of TfVWD to tetrodotoxin and provides a basis for further exploration of the molecular mechanisms underlying the enrichment and transfer of tetrodotoxin in pufferfish.

scholarly journals Direct radioimmune detection in human plasma of the association between factor VIII procoagulant protein and von Willebrand factor, and the interaction of von Willebrand factor-bound procoagulant VIII with platelets

Blood ◽  
1983 ◽  
Vol 61 (6) ◽  
pp. 1163-1173 ◽  
Author(s):  
JL Moake ◽  
MJ Weinstein ◽  
JH Troll ◽  
LE Chute ◽  
NM Colannino
Keyword(s):  
Factor Viii ◽  
Human Plasma ◽  
Von Willebrand Factor ◽  
Sodium Dodecylsulfate ◽  
Coagulation Factors ◽  
Cysteine Protease Inhibitors ◽  
Proteolytic Activation ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The predominant procoagulant factor VIII (VIII:C) form in normal human plasma containing various combinations of anticoagulants and serine/cysteine protease inhibitors is a protein with mol wt 2.6 +/- 0.2 X 10(5). This protein can be detected by 125I-anti-VIII:C Fab binding and gel electrophoresis in the presence and absence of sodium dodecylsulfate (SDS) and is distinct from the subunit of factor VIII/von Willebrand factor (VIII:vWF) multimers. No larger VIII:C form is present in plasma from patients with severe congenital deficiencies of each of the coagulation factors, other than VIII:C. The mol wt approximately 2.6 X 10(5) VIII:C form is, therefore, likely to be the in vivo procoagulant form of VIII:C, rather than a partially proteolyzed, partially activated derivative of a larger precursor. About 60% of this procoagulant mol wt approximately 2.6 X 10(5) VIII:C form in plasma is present in noncovalent complexes with larger VIII:vWF multimers, which attach reversibly to platelet surfaces in the presence of ristocetin. This VIII:vWF-bound protein of mol wt approximately 2.6 X 10(5) may be the plasma procoagulant form of VIII:C which, after proteolytic activation, accelerates the IXa-mediated cleavage and activation of X postulated to occur on platelet surfaces.

Endothelial CD40 Mediates Microvascular von Willebrand Factor-Dependent Platelet Adhesion Inducing Inflammatory Venothrombosis in ADAMTS13 Knockout Mice

2020 ◽  
Vol 120 (03) ◽  
pp. 466-476
Author(s):  
Sibgha Tahir ◽  
Andreas H. Wagner ◽  
Steffen Dietzel ◽  
Hanna Mannell ◽  
Joachim Pircher ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Knockout Mice ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Cd40 Ligand ◽  
Inflammatory Conditions ◽  
String Formation ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Background von Willebrand factor (vWF) plays an important role in platelet activation. CD40–CD40 ligand (CD40L) induced vWF release has been described in large vessels and cultured endothelium, but its role in the microcirculation is not known. Here, we studied whether CD40 is expressed in murine microvessels in vivo, whether CD40L induces platelet adhesion and leukocyte activation, and how deficiency of the vWF cleaving enzyme ADAMTS13 affects these processes. Methods and Results The role of CD40L in the formation of beaded platelet strings reflecting their adhesion to ultralarge vWF fibers (ULVWF) was analyzed in the murine cremaster microcirculation in vivo. Expression of CD40 and vWF was studied by immunohistochemistry in isolated and fixed cremasters. Microvascular CD40 was only expressed under inflammatory conditions and exclusively in venous endothelium. We demonstrate that CD40L treatment augmented the number of platelet strings, reflecting ULVWF multimer formation exclusively in venules and small veins. In ADAMTS13 knockout mice, the number of platelet strings further increased to a significant extent. As a consequence extensive thrombus formation was induced in venules of ADAMTS13 knockout mice. In addition, circulating leukocytes showed primary and rapid adherence to these platelet strings followed by preferential extravasation in these areas. Conclusion CD40L is an important stimulus of microvascular endothelial ULVWF release, subsequent platelet string formation and leukocyte extravasation but only in venous vessels under inflammatory conditions. Here, the lack of ADAMTS13 leads to severe thrombus formation. The results identify CD40 expression and ADAMTS13 activity as important targets to prevent microvascular inflammatory thrombosis.

Multi-Cellular Activation In Vivo by Endotoxin in Humans – Limited Protection by Adenosine Infusion

2000 ◽  
Vol 84 (09) ◽  
pp. 381-387 ◽  
Author(s):  
Nailin Li ◽  
Anne Soop ◽  
Alf Sollevi ◽  
Paul Hjemdahl
Keyword(s):  
Von Willebrand Factor ◽  
Thrombin Generation ◽  
Platelet Reactivity ◽  
Adenosine Infusion ◽  
Cellular Activation ◽  
Soluble P ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Secretion

SummaryThe influence of adenosine infusion (40 µg/kg/min for 4 h) on inflammatory and hemostatic parameters was investigated in healthy males without (n = 10) or with (n = 11) intravenous endotoxin injection (4 ng/kg). Without endotoxin, adenosine elevated circulating leukocytes and circulating platelet-leukocyte aggregates. Endotoxin activated platelets and leukocytes in vivo. Platelet activation was seen as slightly increased platelet P-selectin expression, decreased platelet counts, and elevated plasma soluble P-selectin (from 39.6 ± 3.4 to 68.9 ± 6.6 ng/ml; P <0.01). Leukocyte activation was evidenced by increased CD11b expression (from MFI of 0.54 ± 0.02 to 2.21 ± 0.17; P <0.01) and plasma elastase levels (from 25.3 ± 2.5 to 169.3 ± 22.5 ng/ml; P <0.01). Endotoxin also enhanced platelet and leukocyte responsiveness to in vitro stimulation. Endotoxin induced von Willebrand factor secretion (from 92 ± 8 units to 265 ± 19 units at 4 h; P <0.001) and enhanced thrombin generation in vivo. Endotoxin induced leukocytosis and thus increased circulating platelet-leukocyte, mainly platelet-neutrophil, aggregates. Adenosine caused slight attenuation of platelet reactivity to agonist stimulation, enhanced the endotoxin-induced leukocytosis, and detained more platelet-leukocyte aggregates in circulation, but did not attenuate endotoxin-induced neutrophil elastase secretion, von Willebrand factor secretion, or thrombin generation. Thus, endotoxemia induces multi-cellular activation in vivo. Adenosine inhibits leukocyte adhesion and extravasation, and mildly attenuates platelet responsiveness and soluble P-selectin release. Adenosine has the potential of becoming a therapeutic antiinflammatory drug, but an optimal treatment strategy needs to be developed.

scholarly journals Leukocyte proteases cleave von Willebrand factor at or near the ADAMTS13 cleavage site

Blood ◽  
2009 ◽  
Vol 114 (8) ◽  
pp. 1666-1674 ◽  
Author(s):  
Thomas J. Raife ◽  
Wenjing Cao ◽  
Bonnie S. Atkinson ◽  
Bruce Bedell ◽  
Robert R. Montgomery ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Hot Spot ◽  
Peptide Bond ◽  
Cathepsin G ◽  
Human Neutrophils ◽  
Activity Levels ◽  
Activated Neutrophils ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The function of von Willebrand factor (VWF) is regulated by proteolysis, which limits its multimeric size and ability to tether platelets. The importance of ADAMTS13 metalloprotease in VWF regulation is demonstrated by the association between severe deficiency of ADAMTS13 and thrombotic thrombocytopenic purpura (TTP). However, ADAMTS13 activity levels do not always correlate with the clinical course of TTP, suggesting that other proteases could be important in regulating VWF. We identified 4 leukocyte proteases that cleave the synthetic VWF substrate FRETS-VWF73 and multimeric VWF. Elastase and proteinase 3 (PR3) cleave multimeric VWF and FRETS-VWF73 at the V1607-T1608 peptide bond; cathepsin G and matrix metalloprotease 9 cleave VWF substrates at the Y1605-M1606 and M1606-V1607 bonds, respectively. Isolated intact human neutrophils cleave FRETS-VWF73 at the V1607-T1608 peptide bond, suggesting that elastase or PR3 expressed on leukocyte surfaces might cleave VWF. In the presence of normal or ADAMTS13-deficient plasma, cleavage of FRETS-VWF73 by resting neutrophils is abolished. However, activated neutrophils retain proteolytic activity toward FRETS-VWF73 in the presence of plasma. Although the in vivo relevance remains to be established, these studies suggest the existence of a “hot spot” of VWF proteolysis in the VWF A2 domain, and support the possibility that activated leukocytes may participate in the proteolytic regulation of VWF.

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