title: Combined toxicity of amorphous silica nanoparticles and methylmercury to human lung epithelial cells.
abstract: Exposure to the ambient particulate matters (PM) has been associated with the morbidity and mortality of cardiopulmonary diseases. Compared with coarse particles, ultrafine particles (UFP) absorb or condense higher concentration of toxic air pollutants and are easily inhaled into the lung. However, the combined effects of UFP and air pollutants on human health are still poorly understood. In this study, a co-exposure in vitro model of amorphous silica nanoparticles (nano-SiO2) and methyl mercury (MeHg) was established to investigate their combined effects and the potential joint action type. Lung adenocarcinoma cells (A549) were exposed to either nano-SiO2 or MeHg alone, or a combination of both. Factorial design was applied to analyze their potential joint action type. Higher interfacial energy was observed in the mixed solution of nano-SiO2 and MeHg. The intracellular content of both silicon and mercury in combination group were much higher than those in single exposure groups. In addition, the co-exposure of nano-SiO2 and MeHg enhanced the reactive oxygen species (ROS) generation, lipid peroxidation and reduced the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px). The excessive oxidative stress led to oxidative DNA damage as well as cellular apoptosis. Factorial design analysis demonstrated that additive and synergistic interactions were responsible for the combined toxicity of nano-SiO2 and MeHg.
authors.affiliation: School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China.
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Yu
authors.affiliation: School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China.
authors.forename: Junchao
authors.initials: J
authors.lastname: Duan
authors.affiliation: School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: School of Public Health, Jilin University, Changchun, Jilin 130021, PR China.
authors.forename: Minghua
authors.initials: M
authors.lastname: Jin
authors.affiliation: School of Public Health, Jilin University, Changchun, Jilin 130021, PR China.
authors.forename: Chenxu
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Chemistry, Renmin University of China, Beijing 100872, PR China. Electronic address: yapeiwang@ruc.edu.cn.
authors.forename: Yapei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China. Electronic address: zwsun@hotmail.com.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Sun
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D045744:Cell Line, Tumor; D004249:DNA Damage; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000187:drug effects; D008767:Methylmercury Compounds / Q000633:toxicity*; D053758:Nanoparticles / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D052638:Particulate Matter / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012822:Silicon Dioxide / Q000633:toxicity*
chemical_list: D000393:Air Pollutants; D008767:Methylmercury Compounds; D052638:Particulate Matter; D017382:Reactive Oxygen Species; D012822:Silicon Dioxide; C004925:methylmercuric chloride
keywords: Combined toxicity; Interaction; Methyl mercury; Silica nanoparticles; Ultrafine particles (UFP)