Centre de recherche cardiovasculaire, Inserm Lariboisière U689, hôpital Lariboisière, 41 bd de la Chapelle, 75475 Paris Cedex 10
Cell activation or apoptosis leads to plasma membrane blebbing and the release of microparticles (MP) in the extracellular space. MP are submicron membrane vesicles, which express a panel of oxidized phospholipids and proteins specific to the cells they derived from. Exposure of negatively charged phospholipids and tissue factor confers a procoagulant potential to MP. Elevation of plasma MP levels, particularly those of endothelial origin, reflects cellular injury and appears now as a surrogate marker of vascular dysfunction. MP are also biologically active and stimulate pro-inflammatory responses in target cells. Thus, MP can be seen as instigators of a vicious circle in that they promote pro-thrombogenic and pro-inflammatory responses, as well as cellular dysfunction within the vascular compartment. A better knowledge of MP composition, as well as their effects and the mechanisms leading to their clearance will most likely open up new therapeutic approaches in the treatment of atherothrombosis.