Proteome of endothelial cell-derived procoagulant microparticles.
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.
Banfi
Cristina
C
Department of Pharmacological Sciences, University of Milan, Italy. cristina.banfi@unimi.it
Brioschi
Maura
M
Wait
Robin
R
Begum
Shajna
S
Gianazza
Elisabetta
E
Pirillo
Angela
A
Mussoni
Luciana
L
Tremoli
Elena
E
D000595:Amino Acid Sequence; D017209:Apoptosis; D001777:Blood Coagulation / Q000502:physiology*; D002462:Cell Membrane / Q000648:ultrastructure*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D004798:Enzymes / Q000737:chemistry / Q000302:isolation & purification; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013925:Thromboplastin / Q000032:analysis*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014471:Umbilical Veins
D004798:Enzymes; D010446:Peptide Fragments; D011506:Proteins; D014409:Tumor Necrosis Factor-alpha; D013925:Thromboplastin