Department of Environment & Health, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161, Rome, Italy.
ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Via Anguillarese, 301, 00123 Rome, Italy.
Chemosphere. 2018 Apr;196:35-44. doi: 10.1016/j.chemosphere.2017.12.147. Epub 2017 Dec 26.
Fine airborne particulate matter (PM) has been repeatedly associated with adverse health effects in humans. The PM soluble fraction, and soluble metals in particular, are thought to cause lung damage. Literature data, however, are not consistent and the role of leachable metals is still under debate. In this study, Winter and Summer urban PM aqueous extracts, obtained by using a bio-compatible solution and different contact times at 37 °C, were used to investigate cytotoxic effects of PM in cultured lung epithelial cells (A549) and the role played by the leachable metals Cu, Fe, Zn, Ni, Pb and Cd. Cell viability and migration, as well as intracellular glutathione, extracellular cysteine, cysteinylglycine and homocysteine concentrations, were evaluated in cells challenged with both PM extracts before and after ultrafiltration and artificial metal ion solutions mimicking the metal composition of the genuine extracts. The thiol oxidative potential was also evaluated by an abiotic test. Results demonstrate that PM bioactive components were released within minutes of PM interaction with the leaching solution. Among these are i) low MW (<3 kDa) solutes inducing oxidative stress and ii) high MW and/or water-insoluble compounds largely contributing to thiol oxidation and to increased homocysteine levels in the cell medium. Cu and/or Ni ions likely contributed to the effects of Summer PM extracts. Nonetheless, the strong bio-reactivity of Winter PM extracts could not be explained by the presence of the studied metals. A possible role for PM water-extractable organic components is discussed.
细颗粒物（PM）已被反复证明会对人类健康产生不良影响。PM 的可溶部分，尤其是可溶性金属，被认为会导致肺部损伤。然而，文献数据并不一致，可浸出金属的作用仍存在争议。在这项研究中，使用生物相容性溶液并在 37°C 下不同接触时间，提取冬季和夏季城市 PM 的水提取物，用于研究 PM 在培养的肺上皮细胞（A549）中的细胞毒性作用，以及可浸出金属 Cu、Fe、Zn、Ni、Pb 和 Cd 的作用。在用 PM 提取物孵育细胞之前和之后，通过超滤和模拟真实提取物金属组成的人工金属离子溶液，评估细胞活力和迁移以及细胞内谷胱甘肽、细胞外半胱氨酸、半胱氨酰甘氨酸和同型半胱氨酸浓度。还通过非生物测试评估了硫醇氧化潜力。结果表明，PM 与浸出溶液相互作用几分钟内就释放出了具有生物活性的成分。这些成分包括：i）诱导氧化应激的低分子量（<3 kDa）溶质；ii）对巯基氧化和细胞培养基中同型半胱氨酸水平升高有很大贡献的高分子量和/或不溶于水的化合物。Cu 和/或 Ni 离子可能是夏季 PM 提取物作用的原因。尽管如此，冬季 PM 提取物的强烈生物反应不能用所研究的金属来解释。还讨论了 PM 水可提取有机成分的可能作用。
