Mitochondrial dysfunction in endothelial cells induced by airborne fine particulate matter (<2.5 μm)

: Exposure to ambient fine particulate matter (<2.5 μm; PM2.5 ) increases the risk of the physiopathology of vascular diseases. However, the underlying mechanism, particularly the mitochondrial damage mechanism, of PM2.5 -induced vascular dysfunction is still unclear. In this study, we examined PM2.5 -induced alterations of mitochondrial morphology, and further demonstrated the adverse effects on mitochondrial dynamics and function in vascular endothelial cells. Consequently, cultured EA.hy926 cells were subjected to PM2.5 collected from Beijing. A Cell Counting Assay Kit-8 demonstrated that PM2.5 exposure decreased the proliferation of EA.hy926 cells in a dose-dependent manner. The exposure caused an increment of abnormal mitochondria coupled with the decrease of fusion protein MFN2 and the increase of fission protein FIS1, suggesting that PM2.5 inhibits mitochondrial fusion. Further analyses revealed PM2.5 decreased the mitochondrial membrane potential (ΔΨm) and increased the mitochondrial permeability transport pore opening, eventually resulting in impairments in adenosine triphosphate synthesis. Therefore, it is clearly shown that PM2.5 triggered endothelial toxicity through mitochondria as the target, including the damage of mitochondrial homeostasis.