Subway particles are more genotoxic than street particles and induce oxidative stress in cultured human lung cells
Subway particles are more genotoxic than street particles and induce oxidative stress in cultured human lung cells
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DOI：
10.1021/tx049723c
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发表时间：
2005-01-01
影响因子：
4.1
通讯作者：
Möller, L
中科院分区：
文献类型：
--
作者：
Karlsson, HL;Nilsson, L;Möller, L
流行病学研究表明，空气中的颗粒物与多种不良健康影响之间存在关联。这些影响背后的机制包括氧化应激和炎症。尽管交通导致城市空气中的颗粒物含量很高，但人们在地铁中接触到的颗粒物含量甚至更高。然而，人们对不同城市子环境中的颗粒物的毒性有何不同缺乏了解。本研究的主要目的是比较来自地铁站和附近非常繁忙的城市街道的颗粒物分别损害 DNA 和诱导氧化应激的能力。将培养的人肺细胞 (A549) 暴露于颗粒中，使用单细胞凝胶电泳（彗星测定）分析 DNA 损伤，并通过肺细胞 DNA 中 8-oxo-7,8-二氢-2'-脱氧鸟苷 (8-oxodG) 的形成来测量诱导氧化应激的能力。我们发现地铁颗粒的基因毒性大约是其八倍，引起肺细胞氧化应激的可能性是其四倍。当颗粒、颗粒的水提取物或用金属螯合剂去铁胺甲磺酸盐处理的颗粒与2'-脱氧鸟苷(dG)和8-oxodG一起孵育进行分析时，我们发现地铁颗粒的氧化能力归因于氧化还原活性固体金属。此外，原子组成分析表明，地铁颗粒的主要成分（原子％）由铁组成，主要以磁铁矿（Fe3O4）的形式存在。通过电子显微镜，显示了颗粒与肺细胞之间的相互作用。由于每天有大量的人接触地铁颗粒，地铁颗粒的体外反应性与地铁系统中的高颗粒水平相结合引起了人们的关注。地铁颗粒物对人类健康造成的影响程度需要进一步评估。
Epidemiological studies have shown an association between airborne particles and a wide range of adverse health effects. The mechanisms behind these effects include oxidative stress and inflammation. Even though traffic gives rise to high levels of particles in the urban air, people are exposed to even higher levels in the subway. However, there is a lack of knowledge regarding how particles from different urban subenvironments differ in toxicity. The main aim of the present study was to compare the ability of particles from a subway station and a nearby very busy urban street, respectively, to damage DNA and to induce oxidative stress. Cultured human lung cells (A549) were exposed to particles, DNA damage was analyzed using single cell gel electrophoresis (the comet assay), and the ability to induce oxidative stress was measured as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation in lung cell DNA. We found that the subway particles were approximately eight times more genotoxic and four times more likely to cause oxidative stress in the lung cells. When the particles, water extracts from the particles, or particles treated with the metal chelator deferoxamine mesylate were incubated with 2'-deoxyguanosine (dG) and 8-oxodG was analyzed, we found that the oxidative capacity of the subway particles was due to redox active solid metals. Furthermore, analysis of the atomic composition showed that the subway particles to a dominating degree (atomic %) consisted of iron, mainly in the form of magnetite (Fe3O4). By using electron microscopy, the interaction between the particles and the lung cells was shown. The in vitro reactivity of the subway particles in combination with the high particle levels in subway systems give cause of concern due to the high number of people that are exposed to subway particles on a daily basis. To what extent the subway particles cause health effects in humans needs to be further evaluated.