Objectives To observe the effect on RAS gene expression of different components of PM2.5 on human umbilical vein endothelial cells (HUVEC) and to explore the potential mechanism.
Methods PM2.5 in the atmosphere of Changsha city was collected through 2010-2011. The vascular endothelial cells HUVEC-12 were treated by soluble and insoluble components of PM2.5 (exposure doses: 100 μg/ml, 200 μg/ml and 400 μg/ml, respectively for each two kinds of components) . For the intervention group, HUVEC was exposed to the 400 μg/ml soluble and insoluble extracts of PM2.5, respectively, followed by an intervention of Perindopril in concentration of 10 μmol/l. Cell activity was detected by MTT colorimetric assay. Furthermore, such RAS genes as ACE, ACE2, AT1R and Mas were observed using quantitative RT-PCR.
Results The results showed that the soluble and insoluble components of PM2.5 caused the decrease of cell survival rate in a dose-dependent manner (P<0.05) . The ACE and AT1R mRNA increased after exposure to diverse components of fine particle, while the ACE2 and Mas mRNA decreased (P<0.05) . At the same exposure dose, insoluble components showed more toxicity to cells than that of soluble components (P<0.05) . Meanwhile, according to the results of treatment with ACEI, levels of ACE and AT1R mRNA in cells decreased greatly (P<0.05) .
Conclusions Diverse components of PM2.5 caused different RAS gene expression in vascular endothelial cells. Compared with the soluble components, insoluble components showed more severe toxicity.