PM2.5 exposure decreases viability, migration and angiogenesis in human umbilical vein endothelial cells and human microvascular endothelial cells

Previous studies have confirmed that exposure to particulate matter with a diameter of <= 2.5 mu m (PM2.5) is associated with inflammation. PM2.5 decreases cardiac cell viability and increases apoptosis through overproduction of reactive oxygen species (ROS). In the present study, the role of PM2.5 in ECs was investigated in vitro. Human umbilical vein endothelial cells and human microvascular endothelial cells (ECs) were incubated with PM2.5 (100-800 mu g/ml) to investigate the effects of PM2.5 on EC viability, migration, tube formation and intracellular levels of ROS. Cell viability and cell apoptosis were determined by MTT assay and flow cytometry analysis. Cell migration was assessed using a Boyden chamber assay, and tube formation was determined by matrigel assay. Tumor necrosis factor-a and interleukin-8 levels were measured by ELISA, and ROS levels were assessed with 2', 7' -dichlorofluorescin diacetate. The results indicated that PM2.5 decreases EC viability and increases EC apoptosis in a concentration-dependent manner. PM2.5 also decreased EC tube formation in a dose-dependent manner. The results also demonstrated that PM2.5 suppresses adhesion to EC extracellular matrix proteins. Furthermore, PM2.5 exposure significantly induced ROS generation, indicative of oxidative stress. Finally, it was demonstrated that PM2.5 decreased angiogenesis in vivo. These results suggested that repeated exposure to PM2.5 induces vascular inflammation.