Microparticles (MPs) are biological conveyors that participate in inflammation, thrombosis and angiogenesis. In healthy control subjects platelet-derived (PMPs) contribute about 20% of total circulation MPs, however in stable angina (SA) or acute myocardial infarction (AMI) their share dramatically increase to 70-90% of total MP population.Introduction
Aim of this study was to analyze the role of CD62 and CD42 positive PMPs in stimulation of angiogenesis both in vivo and in vitro conditions.Methods
We analyzed cell proliferation and the neovasculogenesis-specific gene expression profile (eNOS, vWF, CD36, AC133 and VCAM-1) in human umbilical vein endothelial cells (HUVEC) stimulated by PMPs isolated from healthy donors. Moreover we investigated different populations of CD14, CD45 and CD61-positive aggregates in patients with advanced coronary artery disease (CAD) and aortic valve stenosis (AVS) to compare the role of PMPs in plaque formation.Results
PMPs stimulated HUVEC proliferation and eNOS, VCAM-1 as well as vWF gene expression (2.5 times vs control condition) in vitro. Number of CD14, CD45 and CD61-positive aggregates was higher in AVS patients than in CAD ones; however the number of PMPs was increased in patients in CAD with respect to AVS 38 750 (11 931) vs 26 832 (11 436) MP/ml (p=0.01).Conclusions
Platelet-derived microparticles play a role in endothelial cell biology, both in differentiation and proliferation. The progression of vascular atherosclerosis can be regulated by different populations of MPs forming aggregates.