Objective Detect vascular endothelial growth factor induce by platelet-derived microparticles (PMPs) in human umbilical vein endothelial cells (HUVECs) and its downstream transduction pathway. The aim of our study was to discuss the possible mechanism of PMPs effecting on VEGF releasing and its clinical significance in endothelial cells.

Methods Applying the method of flow cytometry (FCM) to isolate platelet-derived microparticles (PMPs) from platelet poor plasma (PPP), and stained with fluorescin isothiocyanate monoclonal antibody against CD61, applying flow cytometry (FCM) method to detect the quantification of PMPs, and the tolal protein concentration of PMPs was determined using Semi-automatic Biochemical Analyser. HUVECs were commonly cultured. Different concentrations of PMPs intervene HUVECs and incubate for different time. We used semi-quantitative reverse transcription PCR techniques to measure VEGF, phosphatidylinositol-3 kinase (PI3K), extracellular signal-regulated kinase (ERK) and VEGF type II receptor (KDR) mRNA levels.

Results 1. High density of PMPs can be obtained from PPP after activation of ADP, Thrombin and detected by FCM. 2. Different concentration of PMPs intervene HUVECs, VEGF mRNA level in control group (non intervention group) was significantly higher than the four different concentration of PMPs groups (p<0.05, respectively). In contrast, KDR mRNA level in control group (non intervention group) was significantly lower than the four different concentration of PMPs groups (p<0.05, respectively). ERK mRNA level in 50 μg/ml PMPs group was significantly higher than the other four groups (1.141 vs 0.749, p=0.004), PI3K mRNA level in 100 μg/ml PMPs group was significantly higher than the other groups (1.344 vs 0.999, p=0.004). 3. Just as the effect of different concentration PMPs on mRNA expression, VEGF mRNA level in control group (non intervention group) was significantly higher than the 24 h intervention time group (0.318 vs 0.746, p<0.001). KDR mRNA level in the 4 h and 24 h groups were significantly higher than control group (p<0.05, respectively). PI3K mRNA level in 24 h group was significantly higher than the control group (2.622 vs 0.999, p=0.004).

Conclusions Abundant PMPs can be obtained from PPP after activation. PMPs may induce the biological processes of blood vessel and angiogenesis via VEGF and its downstream signal transduction pathways.