| Object: In this study, the effects of silicon nanoparticles（SiO2-NPs） on human umbilical vein endothelial cells（HUVECs） and mononuclear cells（THP-1） were explored to provide scientific data for in-depth understanding the potential mechanisms of atherosclerosis due to SiO2-NPs exposure, scientifically evaluating its potential risks on the cardiovascular system, and its rational use.Methods: The transmission electron microscopy（TEM） was used to determine the shape and size of SiO2-NPs and its distribution in the target cells. The proliferation of HUVECs and THP-1 treated with SiO2-NPs was determined by the MTT and CCK-8 methods respectively. The real-time quantitative PCR, enzyme linked immunoabsorbent assay and western blot method were used to detect the expression level of mRNA and proteins of target genes, including VCAM-1, s ICAM-1, MCP-1, IL-6, IL-8, TNF alpha, eNOS, ET-1, TF and PAI-1 in HUVECs or THP-1.Results: Most of SiO2-NPs are round, with sizes of 20±1.2 nm, and they were reunited in PBS. SiO2-NPs could be phagocytosed into HUVECs and THP-1, and impaired their proliferation. On the one hand, they could cause the dysfunction of HUVECs, reducing the expression of eNOS, enhencing the expression of ET-1, make imbalance secretion of NO/ET. They could also promot the relase of chemotactic factor（MCP-1） and adhesion factors（VCAM-1, sICAM-1）, leading to inflammatory response. They might interfer the normal function of blood coagulation/fibrinolysis system through altering the expression of TF and PAI-1in HUVECs. On the other hand, SiO2-NPs could also promote the expression and release of the inflammatory cytokines（IL-6, IL-8 and TNF alpha） in THP-1, triggering the inflammatory response. Of note, SiO2-NPs could promote mononuclear cells adhesion to endothelial cells, and strongly increase the expression of the related inflammatory cytokines, compared to HUVECs or THP-1 alone, showing that SiO2-NPs could promote the interaction between the two kinds of cells. All the toxicological effects of SiO2-NPs on HUVECs and/or THP-1 were found to have a certain relationship of dose-effect.Conclusion: SiO2-NPs could cause HUVECs dysfunction, induce inflammatory response of THP-1 and promote adhesion of monocytes to endothelial cells. |
