Skip to Main content Skip to Navigation
Journal articles

Leukocyte- and endothelial-derived microparticles: a circulating source for fibrinolysis.: Fibrinolytic microparticles

Abstract : BACKGROUND: We recently assigned a new fibrinolytic function to cell-derived microparticles in vitro. In this study we explored the relevance of this novel property of microparticles to the in vivo situation. DESIGN AND METHODS: Circulating microparticles were isolated from the plasma of patients with thrombotic thrombocytopenic purpura or cardiovascular disease and from healthy subjects. Microparticles were also obtained from purified human blood cell subpopulations. The plasminogen activators on microparticles were identified by flow cytometry and enzyme-linked immunosorbent assays; their capacity to generate plasmin was quantified with a chromogenic assay and their fibrinolytic activity was determined by zymography. RESULTS: Circulating microparticles isolated from patients generate a range of plasmin activity at their surface. This property was related to a variable content of urokinase-type plasminogen activator and/or tissue plasminogen activator. Using distinct microparticle subpopulations, we demonstrated that plasmin is generated on endothelial and leukocyte microparticles, but not on microparticles of platelet or erythrocyte origin. Leukocyte-derived microparticles bear urokinase-type plasminogen activator and its receptor whereas endothelial microparticles carry tissue plasminogen activator and tissue plasminogen activator/inhibitor complexes. CONCLUSIONS: Endothelial and leukocyte microparticles, bearing respectively tissue plasminogen activator or urokinase-type plasminogen activator, support a part of the fibrinolytic activity in the circulation which is modulated in pathological settings. Awareness of this blood-borne fibrinolytic activity conveyed by microparticles provides a more comprehensive view of the role of microparticles in the hemostatic equilibrium.
Document type :
Journal articles
Complete list of metadatas

Cited literature [50 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-00711679
Contributor : Eduardo Angles-Cano <>
Submitted on : Monday, June 25, 2012 - 2:51:11 PM
Last modification on : Wednesday, August 19, 2020 - 12:08:19 PM
Long-term archiving on: : Wednesday, September 26, 2012 - 2:50:37 AM

File

haematol.2012.066167.full.pdf
Publisher files allowed on an open archive

Identifiers

Citation

Romaric Lacroix, Laurent Plawinski, Stéphane Robert, Loïc Doeuvre, Florence Sabatier, et al.. Leukocyte- and endothelial-derived microparticles: a circulating source for fibrinolysis.: Fibrinolytic microparticles. Haematologica, Ferrata Storti Foundation, 2012, 97 (12), pp.1864-72. ⟨10.3324/haematol.2012.066167⟩. ⟨inserm-00711679⟩

Share

Metrics

Record views

750

Files downloads

1553