Endothelial microparticles: missing link in endothelial dysfunction?

Vascular homeostasis is an integral reflection of quiescent, but competent endothelium. Endothelial microparticles (EMPs) are circulating submicron-sized membranous vesicles released by endothelium that are increasingly recognized and play a multitude of biological roles reflecting competency of endothelial function and vascular biology. EMPs have been shown to act as primary and secondary messengers of vascular inflammation, thrombosis, vasomotor response, angiogenesis, and endothelial survival. These often-neglected vesicles are emerging as potentially useful indicators of dysfunctioning endothelium, whereby differential presence of EMPs is linked to disease manifestation. In this review, we outline the evolving understanding of EMPs from mere passive vesiculation to active messenger in pathophysiological responses. Current evidence implicating EMPs in cardiopulmonary, renal, cerebral, and metabolic disorders warrants vigorous clinical validation. While studies of EMPs face significant technical challenges that await standardization and consolidation, unravelling its biological significance in endothelial dysfunction could herald the advent of novel non-invasive surveillance platforms for vascular health, risk stratification, and disease prognostication.