title: ROS-generating/ARE-activating capacity of metals in roadway particulate matter deposited in urban environment.
abstract: 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.
authors.affiliation: Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Timor
authors.initials: T
authors.lastname: Shuster-Meiseles
authors.affiliation: Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA; Wisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, WI, USA.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Shafer
authors.affiliation: Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Jongbae
authors.initials: J
authors.lastname: Heo
authors.affiliation: Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Pardo
authors.affiliation: Wisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, WI, USA.
authors.forename: Dagmara S
authors.initials: DS
authors.lastname: Antkiewicz
authors.affiliation: Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA; Wisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, WI, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Schauer
authors.affiliation: Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Assaf
authors.initials: A
authors.lastname: Rudich
authors.affiliation: Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: Yinon.rudich@weizmann.ac.il.
authors.forename: Yinon
authors.initials: Y
authors.lastname: Rudich
mesh_terms: D000336:Aerosols / Q000032:analysis / Q000633:toxicity*; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D002478:Cells, Cultured; D002947:Cities; D004784:Environmental Monitoring; D005374:Filtration; D006115:Greece; D007558:Italy; D008131:London; D008670:Metals / Q000032:analysis / Q000633:toxicity; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D028561:Transition Elements / Q000032:analysis / Q000633:toxicity*; D001335:Vehicle Emissions / Q000032:analysis
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D008670:Metals; D052638:Particulate Matter; D017382:Reactive Oxygen Species; D028561:Transition Elements; D001335:Vehicle Emissions
keywords: ARE; Oxidative stress; Particulate matter; ROS; Soluble metals