title: Differential effects of the particle core and organic extract of diesel exhaust particles.
abstract: Exposure to diesel engine exhaust particles (DEPs), representing a complex and variable mixture of components, has been associated with lung disease and induction of pro-inflammatory mediators and CYP1A1 expression. The aim of this study was to further characterise DEP-components accounting for these effects. Human bronchial epithelial cells (BEAS-2B) were exposed to either native DEPs, or corresponding methanol DEP-extract or residual DEPs, and investigated with respect to cytotoxicity and expression and release of multiple inflammation-related mediators. Both native DEPs and DEP-extract, but not residual DEPs, induced marked mRNA expression of COX-2, IL-6 and IL-8, as well as cytotoxicity and release of IL-6. However, CYP1A1 was primarily induced by the native and residual DEPs. Overall, the results of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and gas chromatography with mass spectrometry (GC/MS) analysis of DEP-extracts indicated that the majority of the analysed PAHs and PAH-derivatives were extracted from the particles, but that certain PAH-derivatives, probably their carboxylic isomers, tended to be retained on the residual DEPs. Moreover, it appeared that certain components of the methanol extract may suppress CYP1A1 expression. These results provide insight into how different components of the complex DEP-mixture may be differently involved in DEP-induced pro-inflammatory responses and underscore the importance of identifying and clarifying the roles of active DEP-components in relation to different biological effects.
authors.affiliation: Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Annike Irene
authors.initials: AI
authors.lastname: Totlandsdal
authors.forename: Jan Inge
authors.initials: JI
authors.lastname: Herseth
authors.forename: Anette Kocbach
authors.initials: AK
authors.lastname: Bølling
authors.forename: Alena
authors.initials: A
authors.lastname: Kubátová
authors.forename: Artur
authors.initials: A
authors.lastname: Braun
authors.forename: Richard E
authors.initials: RE
authors.lastname: Cochran
authors.forename: Magne
authors.initials: M
authors.lastname: Refsnes
authors.forename: Johan
authors.initials: J
authors.lastname: Ovrevik
authors.forename: Marit
authors.initials: M
authors.lastname: Låg
mesh_terms: D000393:Air Pollutants / Q000633:toxicity; D001980:Bronchi / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis / Q000235:genetics; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics; D016209:Interleukin-8 / Q000096:biosynthesis / Q000235:genetics; D008171:Lung Diseases / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001335:Vehicle Emissions / Q000633:toxicity*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D000393:Air Pollutants; D015850:Interleukin-6; D016209:Interleukin-8; D011084:Polycyclic Aromatic Hydrocarbons; D012333:RNA, Messenger; D001335:Vehicle Emissions; D019363:Cytochrome P-450 CYP1A1; D051546:Cyclooxygenase 2