TY - JOUR
T1 - ROS-generating/ARE-activating capacity of metals in roadway particulate matter deposited in urban environment
AU - Shuster-Meiseles, Timor
AU - Shafer, Martin M.
AU - Heo, Jongbae
AU - Pardo, Michal
AU - Antkiewicz, Dagmara S.
AU - Schauer, James J.
AU - Rudich, Assaf
AU - Rudich, Yinon
N1 - Publisher Copyright:
© 2016 Elsevier Inc.
PY - 2016/4/1
Y1 - 2016/4/1
N2 - In this study we investigated the possible causal role for soluble metal species extracted from roadway traffic emissions in promoting particulate matter (PM)-induced reactive oxygen species (ROS) production and antioxidant response element (ARE) promoter activation. To this end, these responses have been evaluated in alveolar macrophage and epithelial lung cells that have been exposed to 'Unfiltered', 'Filtered' and 'Filtered+Chelexed' water extracts of PM samples collected from the roadway urban environments of Thessaloniki, Milan and London. Except for Thessaloniki, our results demonstrate that filtration resulted in a minor decrease in ROS activity of the fine PM fraction, suggesting that ROS activity is attributed mainly to water-soluble PM species. In contrast to ROS, ARE activity was mediated predominantly by the water-soluble component of PM present in both the fine and coarse extracts. Further removal of metals by Chelex treatment from filtered water extracts showed that soluble metal species are the major factors mediating ROS and ARE activities of the soluble fraction, especially in the London PM extracts. Finally, utilizing step-wise multiple-regression analysis, we show that 87% and 78% of the total variance observed in ROS and ARE assays, respectively, is accounted for by changes in soluble metal concentration. Using a statistical analysis we find that As, Zn and Fe best predict the ROS-generating/ARE-activating capacity of the near roadway particulate matter in the pulmonary cells studied. Collectively, our findings imply that soluble metals present in roadside PM are potential drivers of both pro- and anti-oxidative effects of PM in respiratory tract.
AB - In this study we investigated the possible causal role for soluble metal species extracted from roadway traffic emissions in promoting particulate matter (PM)-induced reactive oxygen species (ROS) production and antioxidant response element (ARE) promoter activation. To this end, these responses have been evaluated in alveolar macrophage and epithelial lung cells that have been exposed to 'Unfiltered', 'Filtered' and 'Filtered+Chelexed' water extracts of PM samples collected from the roadway urban environments of Thessaloniki, Milan and London. Except for Thessaloniki, our results demonstrate that filtration resulted in a minor decrease in ROS activity of the fine PM fraction, suggesting that ROS activity is attributed mainly to water-soluble PM species. In contrast to ROS, ARE activity was mediated predominantly by the water-soluble component of PM present in both the fine and coarse extracts. Further removal of metals by Chelex treatment from filtered water extracts showed that soluble metal species are the major factors mediating ROS and ARE activities of the soluble fraction, especially in the London PM extracts. Finally, utilizing step-wise multiple-regression analysis, we show that 87% and 78% of the total variance observed in ROS and ARE assays, respectively, is accounted for by changes in soluble metal concentration. Using a statistical analysis we find that As, Zn and Fe best predict the ROS-generating/ARE-activating capacity of the near roadway particulate matter in the pulmonary cells studied. Collectively, our findings imply that soluble metals present in roadside PM are potential drivers of both pro- and anti-oxidative effects of PM in respiratory tract.
KW - ARE
KW - Oxidative stress
KW - Particulate matter
KW - ROS
KW - Soluble metals
UR - http://www.scopus.com/inward/record.url?scp=84954547378&partnerID=8YFLogxK
U2 - 10.1016/j.envres.2016.01.009
DO - 10.1016/j.envres.2016.01.009
M3 - Article
C2 - 26775006
AN - SCOPUS:84954547378
SN - 0013-9351
VL - 146
SP - 252
EP - 262
JO - Environmental Research
JF - Environmental Research
ER -