全氟辛酸对人肺A549细胞的毒性

Cytotoxicity of PFOA to the epithelial cells of human lungs

采用体外细胞毒性试验的方法研究了全氟辛酸(PFOA)对人肺A549细胞的毒性作用。结果表明:当PFOA质量浓度≥50μg/mL时,细胞皱缩变圆,并随PFOA质量浓度增加,细胞间隙变大,细胞变圆的数量增多;PFOA对A549细胞的增殖存在抑制作用,抑制作用与PFOA质量浓度呈正相关;PFOA会导致细胞内活性氧(ROS)含量升高,PFOA染毒质量浓度与细胞内ROS含量呈正相关;PFOA可诱导细胞凋亡,细胞凋亡率随PFOA质量浓度升高呈缓慢上升趋势。PFOA对人肺癌细胞具有毒性作用,可诱导细胞凋亡,且PFOA可随大气颗粒物进行长距离迁移,其对人体呼吸系统的影响或发生致毒效应的风险应当引起重视。

The present research took the investigation of the cytotoxicity of PFOA to the epithelial cells of human lungs as its research goal in hoping to make an assessment of the potential risk of PFOA to human health. In this paper we adopted 3-（4,5-dimethylthiazol）-2,5-diphenltetrazoliumh romide （MTT） assay for evaluating the cell viability of A549 24 hours later of their exposure to PFOA. What was more, since the MTT assay has the defects of its application and instability, we added alamar Blue assay to test the cell viability of A549 to choose appropriate PFOA doses. In addition, we analyzed the morphological characteristics, the apoptosis rate and the intracellular production of the reactive oxygen species （ROS） of A549 cells by phase-contrast microscope, propidium iodide staining and 2,7-dichlorodihydro fluorescent diacetate （DCFH DA）, respectively. Meanwhile, we measured the ROS and apoptosis of A549 cells by flow cytometry. The results of our tests and measurements showed that the A549 cells began to shrink and turn to be round when they were exposed to PFOA at a concentration over 50 μg/mL and exhibited the dose-dependent effect. Later, both the MTT assay and the alamar Blue assay would reveal that the cell viability of A549 tended to decrease significantly with the increase of the concentration through a 24 h exposure to PFOA. In the mean time, the intracellular ROS and the rate of apoptosis, when induced by PFOA in A549 cells, tended to increase with the increase of the concentration of PFOA. After that, on the basis of the results of A549 cells viability experiments, we conducted the next study in a range of 0-100 μg/mL PFOA. Through a high dosage exposure （100 μg/mL） for 24 h, we found that the intracellular ROS in A549 cells turned to be almost twice as large as that of the control group. What was more, the rate of apoptosis was increased by 2.4% and 6.93% as a result of treated with 50 μg/mL and 100 μg/mL PFOA for 24 h. Thus, the PFOA tended to exhibit the dose-dependent cytotoxicity, causing the inhibition of cell viability, oxidative stress and the apoptosis of A549 cells. Furthermore, we found that it was possible to transfer PFOA to the remote areas, being allowed attached to some kind of airborne particulate matters. Therefore, it was necessary to notice the cytotoxicity of human respiratory system and get rid of it.