von Willebrand factor binds to angiopoietin-2 within endothelial cells and after release from Weibel-Palade bodies
File(s)
Published version
Author(s)
Mobayen, Golzar
Smith, Koval
Ediriwickrema, Kushani
Starke, Richard D
Solomonidis, Emmanouil Georgios
Type
Journal Article
Abstract
BACKGROUND: The von Willebrand factor (VWF) is a multimeric plasma glycoprotein essential for hemostasis, inflammation, and angiogenesis. The majority of VWF is synthesized by endothelial cells (ECs) and stored in Weibel-Palade bodies (WPB). Among the range of proteins shown to co-localize to WPB is angiopoietin-2 (Angpt-2), a ligand of the receptor tyrosine kinase Tie-2. We have previously shown that VWF itself regulates angiogenesis, raising the hypothesis that some of the angiogenic activity of VWF may be mediated by its interaction with Angpt-2. METHODS: Static-binding assays were used to probe the interaction between Angpt-2 and VWF. Binding in media from cultured human umbilical vein ECs s and in plasma was determined by immunoprecipitation experiments. Immunofluorescence was used to detect the presence of Angpt-2 on VWF strings, and flow assays were used to investigate the effect on VWF function. RESULTS: Static-binding assays revealed that Angpt-2 bound to VWF with high affinity (KD,app ∼3 nM) in a pH and calcium-dependent manner. The interaction was localized to the VWF A1 domain. Co-immunoprecipitation experiments demonstrated that the complex persisted following stimulated secretion from ECs and was present in plasma. Angpt-2 was also visible on VWF strings on stimulated ECs. The VWF-Angpt-2 complex did not inhibit the binding of Angpt-2 to Tie-2 and did not significantly interfere with VWF-platelet capture. CONCLUSIONS: Together, these data demonstrate a direct binding interaction between Angpt-2 and VWF that persists after secretion. VWF may act to localize Angpt-2; further work is required to establish the functional consequences of this interaction.
Date Issued
2023-07-01
Date Acceptance
2023-03-22
Citation
Journal of Thrombosis and Haemostasis, 2023, 21 (7), pp.1802-1812
ISSN
1538-7836
Publisher
Elsevier
Start Page
1802
End Page
1812
Journal / Book Title
Journal of Thrombosis and Haemostasis
Volume
21
Issue
7
Copyright Statement
© 2023 Published by Elsevier Inc. on behalf of International Society on Thrombosis and Haemostasis. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/37011710
PII: S1538-7836(23)00258-1
Subjects
angiogenesis
angiopoietin-2
endothelial cells
von Willebrand factor
Weibel–Palade bodies
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2023-04-01