The study of mitochondrial DNA in the pathopoiesis mechanisms of paraquat poisoning in vitro / 中华急诊医学杂志

ABSTRACT

Objective To investigate the effects of mitochondrial DNA (mtDNA) on the pathopoiesis mechanisms of paraquat poisoning in vitro.Methods Firstly,the survival rate of A549 cells (human type Ⅱ alveolar epithelial cells) was measured with cell counting kit-8 after exposure to paraquat.Afterwards,the concentration of mtDNA in supernant of culture medium for culturing A549 and the chauge of mitochondrial membrance potential were detected with absolute quantitative PCR and confocal laser microscopy,respectively.Then,The chemotactic activity of mtDNA in peripheral blood mononuclear cells (PBMC) and neutrophils (PMN) were detected by transwell chemotaxis,and the subtype of chemotactic cells was measured with flow cytometry.Meanwhile,the role of mtDNA in vascular permeability was measured by using Xcelligence system and in vitro using vascular permeability kits.Finally,the effects of mtDNA in cell proliferation were to verify.Results The 50％ of lethal concentration (LD50) of paraquat for A549 was 600 μmol/L.Cell viability and concentration of mtDNA following challenge of PQ revealed in a concentration-and time-dependent manner (P ＜ 0.05).The mtDNA had a power in aggregating PBMC nonspecifically,but there was no effect on the vascular permeability was found.Moreover,the proliferation of human fibroblasts was not stimulated directly by mtDNA,but TGF-β1 (transforming growth factor-beta 1),a major pro-fibrotic factor,was increased compared to control group (P ＜ 0.05).Conclusions The mtDNA could play an important role in the inflammatory and proliferation responses to paraquat poisoning.