Proteome of endothelial cell-derived procoagulant microparticles
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Updated: Aug 15, 2026
Determination of the Procoagulant Activity of Extracellular Vesicle (EV) Using EV-Activated Clotting Time (EV-ACT)
Published on: August 4, 2023
Cristina Banfi1, Maura Brioschi, Robin Wait
1Department of Pharmacological Sciences, University of Milan, Italy. cristina.banfi@unimi.it
Abstract:
Microparticles (MP) are small membrane vesicles that are released from cells upon activation or during apoptosis. Cellular MP in body fluids constitute a heterogeneous population, differing in cellular origin, numbers, size, antigenic composition and functional properties. MP support coagulation by exposure of tissue factor (TF), the initiator of coagulation in vivo. Moreover, MP may transfer bioactive molecules to other cells, thereby stimulating them to produce cytokines, cell-adhesion molecules, growth factors and TF, and modulate endothelial functions. However, a comprehensive characterization of the antigenic composition of MP has been poorly defined. This study describes the protein composition of endothelial cell (EC)-derived MP (EMP) using a proteomic approach. MS analysis indicated the presence of newly described protein such as metabolic enzymes, proteins involved in adhesion and fusion processes, members of protein folding event, cytoskeleton associated proteins and nucleosome. In conclusion, circulating EMP behave as an actual storage pool, able to disseminate blood-borne TF activity and other bioactive effectors, as confirmed by our experiments showing an increased procoagulant activity of EC exposed to EMP.
Insights
This study reveals the protein makeup of endothelial cell-derived microparticles (EMP), showing they store and release bioactive molecules. These EMP enhance blood clotting and influence other cells, impacting endothelial functions.
Area of Science:
- Biochemistry
- Cell Biology
- Hematology
Background:
- Microparticles (MP) are cell-derived vesicles found in body fluids, with diverse origins and functions.
- MP play a role in coagulation via tissue factor (TF) exposure and can transfer bioactive molecules to other cells.
- The detailed antigenic composition of MP, particularly endothelial cell-derived MP (EMP), remains poorly defined.
Purpose of the Study:
- To comprehensively characterize the protein composition of endothelial cell-derived microparticles (EMP).
- To investigate the potential of EMP as a storage pool for bioactive molecules and their role in coagulation.
Main Methods:
- Proteomic analysis using mass spectrometry (MS) was employed to identify proteins within EMP.
- Experiments were conducted to assess the procoagulant activity of endothelial cells (EC) exposed to EMP.
Main Results:
- MS analysis identified a wide range of proteins in EMP, including metabolic enzymes, adhesion/fusion proteins, protein folding factors, cytoskeleton-associated proteins, and nucleosomes.
- EMP were confirmed to increase the procoagulant activity of EC upon exposure, indicating their role in disseminating TF activity.
Conclusions:
- Circulating EMP function as a reservoir for bioactive molecules, including tissue factor.
- EMP can disseminate TF activity and other effectors, modulating endothelial cell functions and enhancing procoagulant activity.
