Role of microparticles in atherothrombosis.
Cell activation or apoptosis leads to plasma membrane blebbing and microparticle (MP) release in the extracellular space. MPs are submicron membrane vesicles which express a panel of phospholipids and proteins specific of the cells they are derived from. Exposure of negatively charged phospholipids and tissue factor confers a procoagulant potential to MPs. MPs accumulate in the lipid core of the atherosclertotic plaque and is a major determinant of its thrombogenecity. Elevation of plasma MPs levels, particularly those of endothelial origin, reflects cellular injury and is considered now as a surrogate marker of vascular dysfunction. Thus, MPs can be seen as triggers of a vicious circle for they promote prothrombogenic and pro-inflammatory responses as well as cellular dysfunction within the vascular compartment. A better knowledge of MP composition and biological effects as well as the mechanisms leading to their clearance will probably open new therapeutic approaches in the treatment of atherothrombosis.
Leroyer
A S
AS
Institut National de la Santé et de la Recherche Médicale (Unit 689), Cardiovascular Research Institute Inserm, Paris, France.
Tedgui
A
A
Boulanger
C M
CM
D017209:Apoptosis; D050197:Atherosclerosis / Q000097:blood / Q000473:pathology* / Q000503:physiopathology; D002462:Cell Membrane / Q000648:ultrastructure*; D003328:Coronary Thrombosis / Q000473:pathology*; D042783:Endothelial Cells / Q000648:ultrastructure*; D004912:Erythrocytes / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008297:Male; D032389:Myocytes, Smooth Muscle / Q000648:ultrastructure