Microparticles: new light shed on the understanding of venous thromboembolism

Abstract

Microparticles are small membrane fragments shed primarily from blood and endothelial cells during either activation or apoptosis. There is mounting evidence suggesting that microparticles perform a large array of biological functions and contribute to various diseases. Of these disease processes, a significant link has been established between microparticles and venous thromboembolism. Advances in research on the role of microparticles in thrombosis have yielded crucial insights into possible mechanisms, diagnoses and therapeutic targets of venous thromboembolism. In this review, we discuss the definition and properties of microparticles and venous thromboembolism, provide a synopsis of the evidence detailing the contributions of microparticles to venous thromboembolism, and propose potential mechanisms, by which venous thromboembolism occurs. Moreover, we illustrate a possible role of microparticles in cancer-related venous thromboembolism.

Figure 1

The role of microparticles in the mechanism of venous thromboembolism. (A) Activated endothelial cells express P-selectin, E-selectin, and vWF and release EMPs; (B) Leukocytes bind to endothelial cells and EMPs via P-selectin and E-selectin; platelets bind to endothelial cells via vWF; (C) These bindings activate leukocytes that induce TF expression and shedding of TF-bearing EMPs, which interact with endothelial cells and activated platelets; (D) The high concentration of TF and wide catalytic surface contribute to thrombosis; EMPs express vWF to stabilize platelet aggregation. EMPs, endothelial microparticles; PSGL-1, P-selectin glycoprotein ligand-1; TF, tissue factor; vWF, von Willebrand factor.