THE ROLE OF MICROPART1CLES IN HEMOSTASIS AND THROMBOSIS

摘要

Microparticles (MPs) are small (0.1-1 uM) vesicles that bud from cell membranes in response to various forms of stimulation. Circulating microparticles are derived from cell membranes of RBCs, platelets, neutrophils, endothelial cells, and monocytes.1'2 MPs express cell surface and cytoplasmic molecules derived from their cell of origin. MPs are able to interact with, and modulate cell signaling and gene expression in other cell types. Recent studies have illustrated their importance as cellular messengers that modify the biologic properties of neighboring and distant cells through delivery of membrane-associated receptors, proteins, cytokines, biologically active lipids, transcription factors, and nucleic acids including mRNA. They are involved innormal hemostasis, vascular homeostasis, apoptosis, innate and adaptive immunity and inflammation, and have prominent roles in pathologic thrombus formation for a number of proinflammatory disease states. Because of their role in pathologic thrombosis, MPs are being investigated as biological markers of thrombotic risk, and as therapeutic targets for thromboprophylaxis for a variety of diseases. This review will summarize recent information regarding the role of microparticles in hemostasis and thrombosis.