title: Oxidative stress and endocytosis are involved in upregulation of interleukin-8 expression in airway cells exposed to PM2.5.
abstract: Inhaled PM2.5 (particulate matter with an aerodynamic diameter of 2.5 μm or less) can induce lung inflammation through released inflammatory mediators from airway cells, such as interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-α). However, the mechanisms underlying PM2.5-induced IL-8 gene expression have not been fully characterized. BEAS-2B cells (a human bronchial epithelial cell line) and THP-1 cells (a human macrophage-like cell line) were used as the in vitro models to investigate the underlying mechanism in this study. IL-8 expression was increased in the cells treated with PM2.5 in a dose-dependent manner. The water-soluble and insoluble fractions of PM2.5 suspension were both shown to induce IL-8 expression. PM2.5 exposure could obviously induce ROS (reactive oxygen species) generation, indicative of oxidative stress. Pretreatment with the antioxidant N-acetyl-l-cysteine (NAC) potently inhibited PM2.5-induced IL-8 expression. Employment of the transition metal chelators including TPEN (N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine) or DFO (desferrioxamine) inhibited IL-8 expression induced by PM2.5 by over 20% in BEAS-2B cells, but had minimal effect in THP-1 cells. Pretreatment with the endocytosis inhibitor CytD markedly blocked IL-8 expression induced by PM2.5 in both BEAS-2B and THP-1 cells. In summary, exposure to PM2.5 induced IL-8 gene expression through oxidative stress induction and endocytosis in airway cells. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1869-1878, 2016.
authors: Department of Industrial Health and Occupational Diseases, College of Public Health, Zhengzhou University, Zhengzhou, China.
authors: Zhen
authors: Z
authors: Yan
authors: Department of Chemistry, Research Institute of Environmental Science, College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, China.
authors: Jia
authors: J
authors: Wang
authors: Department of Industrial Health and Occupational Diseases, College of Public Health, Zhengzhou University, Zhengzhou, China.
authors: Juan
authors: J
authors: Li
authors: Department of Chemistry, Research Institute of Environmental Science, College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, China.
authors: Nan
authors: N
authors: Jiang
authors: Department of Chemistry, Research Institute of Environmental Science, College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, China.
authors: Ruiqin
authors: R
authors: Zhang
authors: Department of Industrial Health and Occupational Diseases, College of Public Health, Zhengzhou University, Zhengzhou, China.
authors: Weichao
authors: W
authors: Yang
authors: Department of Industrial Health and Occupational Diseases, College of Public Health, Zhengzhou University, Zhengzhou, China.
authors: Wu
authors: W
authors: Yao
authors: Department of Environmental and Occupational Health, School of Public Health, Xinxiang Medical University, Xinxiang, China.
authors: Weidong
authors: W
authors: Wu
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000393:Air Pollutants / Q000633:toxicity*; D000975:Antioxidants / Q000494:pharmacology; D001980:Bronchi / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002460:Cell Line; D004705:Endocytosis; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress; D052638:Particulate Matter / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D020545:Respiratory Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000393:Air Pollutants; D000975:Antioxidants; C508606:CXCL8 protein, human; D016209:Interleukin-8; D052638:Particulate Matter; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D000111:Acetylcysteine
keywords: IL-8; PM2.5; ROS; airway cells; endocytosis; transition metals