scholarly journals Role of CD40 and ADAMTS13 in von Willebrand factor-mediated endothelial cell–platelet–monocyte interaction

2018 ◽  
Vol 115 (24) ◽  
pp. E5556-E5565 ◽  
Author(s):  
Miruna Popa ◽  
Sibgha Tahir ◽  
Julia Elrod ◽  
Su Hwan Kim ◽  
Florian Leuschner ◽  
...  

Monocyte extravasation into the vessel wall is a key step in atherogenesis. It is still elusive how monocytes transmigrate through the endothelial cell (EC) monolayer at atherosclerosis predilection sites. Platelets tethered to ultra-large von Willebrand factor (ULVWF) multimers deposited on the luminal EC surface following CD40 ligand (CD154) stimulation may facilitate monocyte diapedesis. Human ECs grown in a parallel plate flow chamber for live-cell imaging or Transwell permeable supports for transmigration assay were exposed to fluid or orbital shear stress and CD154. Human isolated platelets and/or monocytes were superfused over or added on top of the EC monolayer. Plasma levels and activity of the ULVWF multimer-cleaving protease ADAMTS13 were compared between coronary artery disease (CAD) patients and controls and were verified by the bioassay. Two-photon intravital microscopy was performed to monitor CD154-dependent leukocyte recruitment in the cremaster microcirculation of ADAMTS13-deficient versus wild-type mice. CD154-induced ULVWF multimer–platelet string formation on the EC surface trapped monocytes and facilitated transmigration through the EC monolayer despite high shear stress. Two-photon intravital microscopy revealed CD154-induced ULVWF multimer–platelet string formation preferentially in venules, due to strong EC expression of CD40, causing prominent downstream leukocyte extravasation. Plasma ADAMTS13 abundance and activity were significantly reduced in CAD patients and strongly facilitated both ULVWF multimer–platelet string formation and monocyte trapping in vitro. Moderate ADAMTS13 deficiency in CAD patients augments CD154-mediated deposition of platelet-decorated ULVWF multimers on the luminal EC surface, reinforcing the trapping of circulating monocytes at atherosclerosis predilection sites and promoting their diapedesis.

2015 ◽  
Vol 113 (05) ◽  
pp. 1095-1108 ◽  
Author(s):  
Kerstin Möller ◽  
Oliver Adolph ◽  
Jennifer Grünow ◽  
Julia Elrod ◽  
Miruna Popa ◽  
...  

SummaryCo-stimulation via CD154 binding to CD40, pivotal for both innate and adaptive immunity, may also link haemostasis to vascular remodelling. Here we demonstrate that human platelet-bound or recombinant soluble CD154 (sCD154) elicit the release from and tethering of ultra-large (UL) von Willebrand factor (vWF) multimers to the surface of human cultured endothelial cells (ECs) exposed to shear stress. This CD40-mediated ULVWF multimer release from the Weibel-Palade bodies was triggered by consecutive activation of TRAF6, the tyrosine kinase c-Src and phospholipase Cγ1 followed by inositol-1,4,5 tris-phosphate-mediated calcium mobilisation. Subsequent exposure to human washed platelets caused ULVWF multimer-platelet string formation on the EC surface in a shear stress-dependent manner. Platelets tethered to these ULVWF multimers exhibited P-selectin on their surface and captured labelled monocytes from the superfusate. When exposed to shear stress and sCD154, native ECs from wild-type but not CD40 or vWF-deficient mice revealed a comparable release of ULVWF multimers to which murine washed platelets rapidly adhered, turning P-selectin-positive and subsequently capturing monocytes from the perfusate. This novel CD154-provoked ULVWF multimerplatelet string formation at normal to fast flow may contribute to vascular remodelling processes requiring the perivascular or intravascular accumulation of pro-inflammatory macrophages such as arteriogenesis or atherosclerosis.


2020 ◽  
Vol 120 (03) ◽  
pp. 466-476
Author(s):  
Sibgha Tahir ◽  
Andreas H. Wagner ◽  
Steffen Dietzel ◽  
Hanna Mannell ◽  
Joachim Pircher ◽  
...  

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.


Author(s):  
Jialing Bao ◽  
Biying Mo ◽  
Guozhen An ◽  
Jian Luo ◽  
Mortimer Poncz ◽  
...  

Microsporidia are a group of spore-forming, fungus-related pathogens that can infect both invertebrates and vertebrates including humans. The primary infection site is usually digestive tract, but systemic infections occur as well and cause damages to organs such as lung, brain, and liver. The systemic spread of microsporidia may be intravascular, requiring attachment and colonization in the presence of shear stress. Von Willebrand Factor (VWF) is a large multimeric intravascular protein and the key attachment sites for platelets and coagulation factors. Here in this study, we investigated the interactions between VWF and microsporidia Encephalitozoon hellem (E. hellem), and the modulating effects on E. hellem after VWF binding. Microfluidic assays showed that E. hellem binds to ultra-large VWF strings under shear stress. In vitro germination assay and infection assay proved that E. hellem significantly increased the rates of germination and infection, and these effects would be reversed by VWF blocking antibody. Mass spectrometry analysis further revealed that VWF-incubation altered various aspects of E. hellem including metabolic activity, levels of structural molecules, and protein maturation. Our findings demonstrated that VWF can bind microsporidia in circulation, and modulate its pathogenicity, including promoting germination and infection rate. VWF facilitates microsporidia intravascular spreading and systemic infection.


1989 ◽  
Vol 109 (1) ◽  
pp. 367-375 ◽  
Author(s):  
E Dejana ◽  
M G Lampugnani ◽  
M Giorgi ◽  
M Gaboli ◽  
A B Federici ◽  
...  

Von Willebrand factor (vWF) is a constitutive and specific component of endothelial cell (EC) matrix. In this paper we show that, in vitro, vWF can induce EC adhesion and promote organization of microfilaments and adhesion plaques. In contrast, human vascular smooth muscle cells and MG63 osteosarcoma cells did not adhere and spread on vWF. Using antibodies to the beta chains of fibronectin (beta 1) and vitronectin (beta 3) receptors it was found that ECs adherent to vWF show clustering of both receptors. The beta 1 receptor antibodies are arranged along stress fibers at sites of extracellular matrix contact while the beta 3 receptor antibodies were sharply confined at adhesion plaques. ECs release and organize endogenous fibronectin early during adhesion to vWF. Upon blocking protein synthesis and secretion, ECs can equally adhere and spread on vWF but, while the beta 3 receptors are regularly organized, the beta 1 receptors remain diffuse. This suggests that the organization of the beta 1 receptors depend on the release of fibronectin and/or other matrix proteins operated by the same cell. Antibodies to the beta 3 receptors fully block EC adhesion to vWF and detach ECs seeded on this substratum. In contrast, antibodies to the beta 1 receptors are poorly active. Overall these results fit with an accessory role of beta 1 receptors and indicate a leading role for the beta 3 receptors in EC interaction with vWF. To identify the EC binding domain on vWF we used monoclonal antibodies produced against a peptide representing the residues Glu1737-Ser1750 of the mature vWF and thought to be important in mediating its binding to the platelet receptor glycoprotein IIb-IIIa. We found that the antibody that recognizes the residues 1,744-1,746, containing the Arg-Gly-Asp sequence, completely inhibit EC adhesion to vWF whereas a second antibody recognizing the adjacent residues 1,740-1,742 (Arg-Gly-Asp-free) is inactive. Both antibodies do not interfere with EC adhesion to vitronectin. This defines the molecular domain on vWF that is specifically recognized by ECs and reaffirms the direct role of the Arg-Gly-Asp sequence as the integrin receptor recognition site also in the vWF molecule.


1997 ◽  
Vol 77 (06) ◽  
pp. 1077-1080 ◽  
Author(s):  
Andrew D Blann ◽  
Gregory Y H Lip ◽  
D Gareth Beevers ◽  
Charles N McCollum

Summaryvon Willebrand factor and soluble thrombomodulin are established plasma markers of endothelial cell dysfunction, whilst beta thromboglobulin is an established plasma marker of platelet activity. Soluble P-selectin may be the product of either or both types of cell and levels of all four molecules have been previously found to be increased in atherosclerosis. To determine the relationship of soluble P-selectin to the endothelial cell and platelet products, we measured the four indices in a case control study of 55 patients with peripheral vascular disease and 55 age and sex matched controls, von Willebrand factor (p <0.0001), beta thromboglobulin (p = 0.0006), soluble P-selectin (p = 0.0021) and soluble thrombomodulin (p = 0.021) were all raised in the patients. Soluble P-selectin correlated with beta thromboglobulin (r = 0.34, p = 0.019) but failed to correlate with either endothelial cell marker. Co-culture of endothelial cells in vitro with bovine thrombin resulted in increased levels of von Willebrand factor in the supernatants but levels of soluble thrombomodulin and soluble P-selectin were not enhanced. Exposure of endothelial cell monolayers to elastase resulted in different patterns of release of von Willebrand factor, soluble thrombomodulin and soluble P-selectin. We suggest that soluble P-selectin is unlikely to arise from the endothelium and may be a new marker of platelet activation in atherosclerosis.


2018 ◽  
Vol 2 (18) ◽  
pp. 2347-2357 ◽  
Author(s):  
Thejaswi Kalagara ◽  
Tracy Moutsis ◽  
Yi Yang ◽  
Karin I. Pappelbaum ◽  
Anne Farken ◽  
...  

Abstract The dynamic change from a globular conformation to an elongated fiber determines the ability of von Willebrand factor (VWF) to trap platelets. Fiber formation is favored by the anchorage of VWF to the endothelial cell surface, and VWF-platelet aggregates on the endothelium contribute to inflammation, infection, and tumor progression. Although P-selectin and ανβ3-integrins may bind VWF, their precise role is unclear, and additional binding partners have been proposed. In the present study, we evaluated whether the endothelial glycocalyx anchors VWF fibers to the endothelium. Using microfluidic experiments, we showed that stabilization of the endothelial glycocalyx by chitosan oligosaccharides or overexpression of syndecan-1 (SDC-1) significantly supports the binding of VWF fibers to endothelial cells. Heparinase-mediated degradation or impaired synthesis of heparan sulfate (HS), a major component of the endothelial glycocalyx, reduces VWF fiber–dependent platelet recruitment. Molecular interaction studies using flow cytometry and live-cell fluorescence microscopy provided further evidence that VWF binds to HS linked to SDC-1. In a murine melanoma model, we found that protection of the endothelial glycocalyx through the silencing of heparanase increases the number of VWF fibers attached to the wall of tumor blood vessels. In conclusion, we identified HS chains as a relevant binding factor for VWF fibers at the endothelial cell surface in vitro and in vivo.


Circulation ◽  
2013 ◽  
Vol 128 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Karin I. Pappelbaum ◽  
Christian Gorzelanny ◽  
Sandra Grässle ◽  
Jan Suckau ◽  
Matthias W. Laschke ◽  
...  

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 764-764
Author(s):  
Qizhen Shi ◽  
Scot A. Fahs ◽  
Erin L. Kuether ◽  
Robert R. Montgomery

Abstract von Willebrand factor (VWF) is a carrier protein for factor VIII (FVIII) and protects plasma FVIII from protease degradation. Our laboratory has had a longstanding interest in the association of FVIII with VWF both in vitro and in vivo. Our in vitro studies have demonstrated that FVIII stores together with VWF in both endothelial cells and megakaryocytes if FVIII is made in these cells. Furthermore, we demonstrated that FVIII and VWF are both releasable by agonist stimulation. To investigate the association of VWF and FVIII in vivo, we generated two lines of transgenic mice that express FVIII either in endothelial cells or in platelets using either the endothelial cell-specific Tie2 promoter or the platelet-specific αIIb promoter, respectively. When the platelet-specific FVIII (2bF8) transgene is bred into the FVIIInull mouse, FVIII can only be detected in platelets, with a level of 0.76 ± 0.27 mU/108 platelets in heterozygous and 1.53 ± 0.14 mU/108 platelets in homozygous 2bF8 mice. When the endothelial cell-specific FVIII (Tie2F8) transgene is bred into the FVIIInull mouse, homozygous Tie2F8 mice maintained normal plasma FVIII levels (1.15 ± 0.16 U/ml) and 50% levels in heterozygous mice (0.56 ± 0.16 U/ml). Both 2bF8trans and Tie2F8trans phenotypes effectively abrogate the bleeding diathesis in hemophilic mice. When 2bF8 transgene was bred into a FVIII and VWF double knockout background, the level of platelet-FVIII significantly decreased, but this platelet-derived FVIII was still stored in a-granules and still maintained clinical efficacy. In contrast, when the Tie2F8 transgene was bred into the double knockout background, plasma FVIII dropped to undetectable levels. This is in contrast to the situation in VWFnull mice in which normal endogenous murine FVIII is synthesized with about 10% of normal FVIII activity persisting in plasma. This could be due to a difference in survival between human FVIII and murine FVIII. All Tie2F8trans/FVIIInullVWFnull mice (n=15) survived tail clipping even though there is no FVIII:C detected in the plasma. To investigate the effect of murine VWF on the levels of plasma FVIII, plasma from FVIIInull mice was infused into Tie2F8trans/FVIIInullVWFnull mice to restore VWF levels to 25% of normal. As expected, the endothelial cell-derived plasma FVIII was stabilized by the infused VWF and was detected within 1 hour after infusion, with a peak (25% level) at 4 hours. The level of plasma FVIII at 24 hours was still about 20% of normal while the level of remaining VWF was only 5% of normal. These results demonstrate that VWF is important for site-specific FVIII expression. Co-expression with VWF in platelets is important for optimal platelet-specific FVIII expression and endothelial cell-derived plasma FVIII is VWF-dependent.


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