Heterogeneous Detection of A-antigen on von Willebrand Factor Derived from Platelets, Endothelial Cells and Plasma

SummaryThe exact function of the carbohydrate component of von Willebrand factor (VWF) is unknown. ABO blood group antigens are present as integral structures on the oligosaccharide side chains and it has long been recognised that ABO blood group is a determinant of VWF levels. The mechanism for this is not known. Using a monoclonal antibody against the A-antigen, we investigated the presence of this antigen on VWF from plasma, platelets, human umbilical vein endothelial cells (HUVEC) and saphenous vein endothelial cells. Initial studies on plasma VWF revealed that 23.5% of samples appeared to be negative for the A-antigen. This was shown to correlate with the A2 subtype of the A-antigen (p <0.01). Analysis of intracellular VWF from saphenous vein endothelial cells revealed low levels of A-antigen to be present in comparison to the corresponding plasma VWF. In contrast, VWF from platelets and HUVEC gave no detectable A-antigen. However, within 1 h of administration of DDAVP to type 1 VWD patients, there was a >2-fold increase in the A-antigen/VWF:Ag ratio for VWF in the plasma. In vitro experiments with serum N-acetlygalactosaminyltransferase failed to demonstrate any addition of A-antigen to platelet or HUVEC VWF. These data are consistent with heterogeneity in the content of A-antigen on VWF from different physiological compartments. Also, they are consistent with either a change in the A-antigen content of VWF after release from the intracellular compartment or a difference in the intracellular addition of A-antigen to VWF by endothelium from different vascular beds.

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ABO blood group is a determinant of von Willebrand factor protein levels in human pulmonary endothelial cells

Journal of Clinical Pathology ◽

10.1136/jclinpath-2019-206182 ◽

2019 ◽

Vol 73 (6) ◽

pp. 347-349 ◽

Cited By ~ 12

Author(s):

Glenn P Murray ◽

Steven R Post ◽

Ginell R Post

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Blood Group ◽

Von Willebrand Factor ◽

Blood Type ◽

Abo Blood Group ◽

Blood Group Antigens ◽

Protein Levels ◽

Von Willebrand ◽

Willebrand Factor

ABO blood group antigens are expressed on von Willebrand factor (VWF) and glycosylation patterns influence circulating VWF levels. The aim of this study was to examine the effect of ABO blood type on tissue-associated VWF protein levels. We selected 35 formalin-fixed paraffin-embedded pulmonary tissue blocks obtained at autopsy from decedents who died from pulmonary embolism with known ABO blood groups (O, A, B and AB phenotypes), prepared tissue microarrays (TMAs) and stained TMAs with antibodies to VWF and platelet/endothelial cell adhesion marker-1 (PECAM-1) as a marker of endothelial cells. A pixel count scoring algorithm was used to quantify VWF and PECAM-1 staining intensity in pulmonary arterioles in digitised images. Compared with type O, non-O individuals have a significantly higher amount of endothelial cell-associated VWF protein expression. VWF protein levels associated with pulmonary vascular endothelial cells is influenced by ABO antigenic determinants.

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ABO Blood Group Antigens on Human Plasma von Willebrand Factor After ABO-Mismatched Bone Marrow Transplantation

Blood ◽

10.1182/blood.v94.8.2895.420a03_2895_2900 ◽

1999 ◽

Vol 94 (8) ◽

pp. 2895-2900 ◽

Cited By ~ 41

Author(s):

Taei Matsui ◽

Taketo Shimoyama ◽

Masanori Matsumoto ◽

Yoshihiro Fujimura ◽

Yoshinobu Takemoto ◽

...

Keyword(s):

Bone Marrow ◽

Endothelial Cells ◽

Stem Cell ◽

Bone Marrow Transplantation ◽

Stem Cell Transplantation ◽

Blood Group ◽

Abo Blood Group ◽

Blood Group Antigens ◽

Von Willebrand ◽

Willebrand Factor

von Willebrand factor (vWF) is synthesized exclusively by endothelial cells and megakaryocytes, and stored in the intracellular granules or constitutively secreted into plasma. ABO blood group antigens are covalently associated with asparagine-linked sugar chains of plasma vWF. The effect of ABO-mismatched bone marrow transplantation (BMT) or blood stem cell transplantation (BSCT) on the expression of ABO blood group antigens on the vWF was examined to obtain information on the origin of these antigens. In ABO-mismatched (HLA-matched) groups, 8 cases of BMT and 4 cases of BSCT were examined. In all cases, the ABO blood groups on red blood cells were gradually converted to the donor’s type within 80 to 90 days after the transplantation. The blood group antigens on the vWF were consistent with the recipient’s blood group for the period monitored by enzyme-linked immunosorbent assay (ELISA). When vWF was isolated from normal platelets and examined for the blood group antigens using ELISA or immunoblotting, it showed few antigens. However, vWF extracted from veins expressed blood group antigens. These findings indicate that platelet (megakaryocyte)-derived vWF does not contain blood group antigens and that these antigens may be specifically associated with vWF synthesized in endothelial cells and secreted into plasma. Furthermore, it is possible that the persistence of the recipient’s blood group antigens on plasma glycoproteins such as vWF, independent of the donor-derived erythrocytes, after ABO-mismatched stem cell transplantation, may influence the immunological system in the production of anti-blood group antibodies resulting in the establishment of immunological tolerance in the recipient plasma.

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

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656135 ◽

1997 ◽

Vol 77 (06) ◽

pp. 1182-1188 ◽

Cited By ~ 74

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.

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Hydrogen peroxide stimulates exocytosis of von Willebrand factor in human umbilical vein endothelial cells

Biology Bulletin ◽

10.1134/s106235901705003x ◽

2017 ◽

Vol 44 (5) ◽

pp. 531-537 ◽

Cited By ~ 2

Author(s):

P. V. Avdonin ◽

A. A. Tsitrina ◽

G. Y. Mironova ◽

P. P. Avdonin ◽

I. L. Zharkikh ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Endothelial Cells ◽

Von Willebrand Factor ◽

Umbilical Vein ◽

Human Umbilical Vein ◽

Umbilical Vein Endothelial Cells ◽

Von Willebrand ◽

Willebrand Factor

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ABO blood group also influences the von Willebrand factor (VWF) antigen level in heterozygous carriers of VWF null alleles, type 2N mutation Arg854Gln, and the missense mutation Cys2362Phe

Blood ◽

10.1182/blood-2002-04-1168 ◽

2002 ◽

Vol 100 (5) ◽

pp. 1927-1928 ◽

Cited By ~ 14

Author(s):

Giancarlo Castaman ◽

Jeroen C. J. Eikenboom

Keyword(s):

Missense Mutation ◽

Blood Group ◽

Von Willebrand Factor ◽

Null Alleles ◽

Abo Blood Group ◽

Antigen Level ◽

Heterozygous Carriers ◽

Von Willebrand ◽

Willebrand Factor

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Abstract 37: Secretion of von Willebrand Factor by Endothelial Cells Links Salt to Hypercoagulability and Thrombosis

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.37 ◽

2014 ◽

Vol 34 (suppl_1) ◽

Author(s):

Natalia I Dmitrieva ◽

Maurice B Burg

Keyword(s):

Endothelial Cells ◽

Von Willebrand Factor ◽

Salt Intake ◽

Umbilical Vein ◽

Coagulation Cascade ◽

Water Restriction ◽

Fibrinogen Degradation Product ◽

Modifiable Factors ◽

Von Willebrand ◽

Willebrand Factor

Hypercoagulability increases the risk of thrombi that cause cardiovascular events. Dehydration and hypernatremia are often accompanied by thrombosis, but the mechanisms are not clear. Von Willebrand Factor is secreted by endothelium, affecting aggregation of platelets and promoting activation of the coagulation cascade and formation of thrombi. Here we show that in culture of primary Human Umbilical Vein Endothelia Cells, elevating medium osmolality to 320-380 mosmol/kg by adding NaCl reversibly increases both vWF mRNA and vWF secretion. The high NaCl increases expression of tonicity regulated transcription factor NFAT5 and its binding to promoter of vWF gene, suggesting that vWF upregulation is caused by hypertonic signaling. To elevate NaCl in vivo, we modeled mild dehydration, subjecting mice to water restriction (WR) for 9 days by feeding them with gel food containing 30% of water. Such WR elevates blood sodium from 145.1±0.5 to 150.2±1.3 mmol/l and activates hypertonic signaling as evidenced from increased expression of NFAT5 in tissues. WR increased vWF mRNA in liver and lung and raised vWF protein in blood. Immunostaining of liver revealed increased production of vWF protein by endothelium and increased number of microthrombi inside capillaries. WR also increased blood level of D-dimer, a fibrinogen degradation product indicative of ongoing coagulation and thrombolysis. We conclude that elevation of extracellular sodium within the physiological range raises expression and secretion of von Willebrand Factor sufficiently to increase coagulability of blood and risk of thrombosis. The results suggest that hydration and salt intake are modifiable factors that affect coagulability and thrombosis through high salt-dependent secretion of vWF from endothelial cells.

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ABNORMAL EXPRESSION OF VON WILLEBRAND FACTOR BY ENDOTHELIAL CELLS FROM A PATIENT WITH TYPE IIA VON WILLEBRAND’ S DISEASE

10.1055/s-0038-1642915 ◽

1987 ◽

Author(s):

Richard B Levene ◽

Francis M Booyse ◽

Juan Chediak ◽

Therodore S Zimmerman ◽

David M Livingston ◽

...

Keyword(s):

Endothelial Cells ◽

Von Willebrand Factor ◽

Umbilical Vein ◽

Kinetic Studies ◽

Protein Product ◽

Polymerization Reaction ◽

Full Spectrum ◽

Endogenous Proteases ◽

Von Willebrand ◽

Willebrand Factor

Studies were conducted to characterize the biosynthesis of von Willebrand factor (vWf) by cultured endothelial cells (EC) derived from the umbilical vein of a patient with type HA von Willebrand’ s disease. The patient’ s EC, compared with those from normal individuals, produced vWf which had decreased amounts of large multimers and an increase in rapidly migrating satellite species, features which are characteristic of plasma vWf from patients with type IIA von Willebrand’ s disease. The typQ IIA EC produced a full spectrum of vWf multimers in both cell lysates and post-culture medium, although the relative amounts of the larger species were decreased. The large multimers were degraded in conjunction with the appearance of rapidly migrating satellites which contained =170 kDa proteolytic fragments. Kinetic studies demonstrated that the =170 kDa species is not a primary translation product Normal metabolically labeled vWf, incubated with either the patient’ s EC or medium conditioned by these cells, was not similarly degraded. These results demonstrated that this patient’ s clinical phenotype is due to abnormal proteolysis and not to a primary failure of subunit oligomerization. Moreover, the increased degradation is attributable to increased proteolytic sensitivity of an abnormal vWf molecule rather than to pathologically elevated levels of endogenous proteases. Experiments using monoclonal antibodies which recognize either N- or C-associated epitopes have localized the defect to the N-terminal portion of the vWf molecule, which is believed to be involved in the inter-dimer polymerization reaction. The type DA EC also contained a single vWf mRNA species which comigrated with that from normal EC. However, the type HA EC contained 8-10 fold more vWf mRNA than their normal counterparts. These results suggest that the functional defect in this patient is caused by a subtle mutation in the vWf coding sequence leading to increased proteolytic sensitivity of its protein product

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Genetic determinants of VWF clearance and FVIII binding modify FVIII pharmacokinetics in pediatric hemophilia A patients

Blood ◽

10.1182/blood.2019000190 ◽

2019 ◽

Vol 134 (11) ◽

pp. 880-891 ◽

Cited By ~ 7

Author(s):

Laura L. Swystun ◽

Kenichi Ogiwara ◽

Orla Rawley ◽

Christine Brown ◽

Ilinca Georgescu ◽

...

Keyword(s):

Blood Group ◽

Von Willebrand Factor ◽

Half Life ◽

Hemophilia A ◽

Blood Type ◽

Abo Blood Group ◽

Genetic Determinants ◽

Group Status ◽

Von Willebrand ◽

Willebrand Factor

Abstract Factor VIII (FVIII) pharmacokinetic (PK) properties show high interpatient variability in hemophilia A patients. Although previous studies have determined that age, body mass index, von Willebrand factor antigen (VWF:Ag) levels, and ABO blood group status can influence FVIII PK, they do not account for all observed variability. In this study, we aim to describe the genetic determinants that modify the FVIII PK profile in a population of 43 pediatric hemophilia A patients. We observed that VWF:Ag and VWF propeptide (VWFpp)/VWF:Ag, but not VWFpp, were associated with FVIII half-life. VWFpp/VWF:Ag negatively correlated with FVIII half-life in patients with non-O blood type, but no correlation was observed for type O patients, suggesting that von Willebrand factor (VWF) half-life, as modified by the ABO blood group, is a strong regulator of FVIII PK. The FVIII-binding activity of VWF positively correlated with FVIII half-life, and the rare or low-frequency nonsynonymous VWF variants p.(Arg826Lys) and p.(Arg852Glu) were identified in patients with reduced VWF:FVIIIB but not VWF:Ag. Common variants at the VWF, CLEC4M, and STAB2 loci, which have been previously associated with plasma levels of VWF and FVIII, were associated with the FVIII PK profile. Together, these studies characterize the mechanistic basis by which VWF clearance and ABO glycosylation modify FVIII PK in a pediatric population. Moreover, this study is the first to identify non-VWF and non-ABO variants that modify FVIII PK in pediatric hemophilia A patients.

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