Oxidative Stress And Cytotoxicity Are Induced In The Human Bronchial Epithelial Cells?16HBE? Exposed To The Urban Particulate Matter (PM_2.5) Of Ya'an Urban

Recently,the haze occurred frequently,which impacted on the human health,thus,many researchers focused on the mechanism of the haze.Fine-particulate matter with a diameter of 2.5 microns or less(PM_2.5),is the main component of the haze.PM_2.5 can be directly inhaled into the lungs,causes the oxidative damage and the inflammatory response,and finally results in many diseases such as the high blood pressure,the atherosclerosis,the blood coagulation,the anti-coagulation imbalance,and disorder of the autonomic nervous system,etc.3.2 million people died from PM_2.5 pollution each year in the worldwide.PM_2.5 ranked at the sixth of the death causes.Ya'an is located on the border of the western Sichuan basin.The haze occurs more frequently than before,which threats the human health,because the industry in Ya'an develops rapidly,and the haze of the surrounding cities can enter into Ya'an urban.Thus,in this study,it was investigated whether PM_2.5 from Yucheng district of Ya'an impacted on the oxidative stress and cytotoxicity of 16HBE,which will provide the theoretical foundation for studying the bio-functions of PM_2.5,and preventing and curing PM_2.5-related diseases.In this study,PM_2.5 were collected from Ya'an urban with TE-6070-2.5 style huge flow sampler and oblong quartz fiber filter membrane?QFF?to analyze the chemical composition.The organic matters and soluble ions in PM_2.5 were extracted by the mixed organic reagents?methanol:dichloromethane=1:1?and deionized water,respectively,and mixed together to treat 16HBE.16HBE was pulsed for 24 h with PM_2.5 extract at 6.25,12.5,25,50 and 100 ?g/mL of the concentration,the viability,the cell cycle,the apoptosis,ROS and MDA levels,and SOD activity of 16HBE were detected by CCK-8,FCM,the fluorescent microscope,and the spectrophotometry,respectively.PM_2.5 from Ya'an consisted of 19.8 ± 11.9 ?g/m³ of the organic carbon?OC?,and 1.26± 0.76 ?g/m³ of the elemental carbon?EC?,and,7 ions and 15 metallic elements were identified.The trend of ions concentration in PM_2.5 was SO₄^2->NO₃^->NH₄^->K⁺>Cl^->Na⁺>Ca²⁺>Mg²⁺,and trend of the metallic elemental concentration were Al>Fe>Zn>Mn>Pb>Ba>Cu>Cr>Ti>Sr>As>Cd>Ni>Mo>V.PM_2.5 extracts significantly inhibited the proliferation of 16HBE at the dose-dependent manner.Moreover,PM_2.5 extracts at the higher concentration induced 16HBE to arrest in G2/M phase and inhibited the mitosis of the cell cycle.Furthermore,compared to the control group,the distorted cell nucleus of 16HBE was observed because PM_2.5 extracts might increase the cell apotosis.In addition,the strong oxidative stress was elicited by PM_2.5 extract,which was characterized with up-regulating the level of the reactive oxygen species?ROS?,down-regulating the level of total superoxide dismutase?T-SOD?and Cu/Zn-SOD,and increasing the level of MDA in 16HBE cellIn conclusion,PM_2.5 from Ya'an urban caused the strong cytotoxicity and oxidative stress on 16HBE cells.These results provided insight into the underling threat of air pollution in human health,and help us to improve the environmental protection awareness.