Platelet derived microparticles (PMPs) are qualitatively and quantitatively diverse, depending on the proaggregatory agent challenge. Shedding of procoagulant PMPs is mediated by integrin-related mechanism. However the role of coagulation activators in microparticles formation and their potential angiogenic activity is scarcely known.Introduction
Aim of this study was to compare pro-angiogenic potential of PMPs obtained by different proaggregatory stimulation on endothelial cells and analysis of gene expression profile and capillary-like structure formation after endothelial cell exposure to different classes of PMPs.Methods
PMPs were obtained by stimulation with agonists: ADP, collagen and thrombin. Human umbilical vein endothelial cells (HUVEC) were treated with 30 ug/ml of PMPs. HUVEC proliferation and pro-angiogenetic gene expression profile (VCAM-1, CD36, AC133, eNOS and vWF) measured by the quantitative real-time PCR method were analyzed. For the angiogenic properties the PMPs-induced the length of capillary-like structures formed by HUVECs was compared. The other HUVEC proangiogenic/invasive potential was measured by chemotaxis in the matrigel method.Results
All kind of PMPs significantly stimulated microvascularisation in vitro. However, only the enhanced eNOS gene expression was observed in HUVEC after thrombin, collagen as well as ATP induced PMPs treatment. Different PMPs induced HUVEC chemotactiv invasions, however collagen induced PMPs gave the strongest stimuli.Conclusions
Platelet derived microparticles generated by the different agonists' stimulation have a significant angiogenetic potential. The role of nitric oxide in this process seems to be significant.