title: The ability of oxidative stress to mimic quartz-induced chemokine responses is lung cell line-dependent.
abstract: Oxidative stress induced by surface-generated radicals has been a dominating hypothesis to explain how mineral particles and fibers trigger cellular responses. However, conflicting studies suggest that the importance of particle-derived formation of reactive oxygen species (ROS) requires further examination. The present study focuses on whether oxidative stress in the form of H(2)O(2)-exposure may mimic the effects of quartz particles on chemokine responses in epithelial lung cells. The results show that H(2)O(2) and quartz exposure induced almost identical levels of CXCL8 (interleukin-8) release in the alveolar epithelial cell line A549, but in the bronchial epithelial cell line BEAS-2B, H(2)O(2)-exposure did not affect CXCL8 release significantly, whereas quartz induced a 16-fold increase. Among 17 different cytokine and chemokine genes H(2)O(2) induced up-regulation of only IL-5 in BEAS-2B cells, while quartz increased the expression of 8 different cytokines and chemokines. In A549 cells, however, there was a moderate but significant correlation between the cytokine/chemokine gene-expression profiles induced by the two agents. Thus, the response to oxidative stress may vary considerably between different lung cell lines. Moreover, the results from the BEAS-2B cells strengthen the notion that non-oxidant initiation mechanisms may also be important to the effects of mineral particles and fibers.
authors.affiliation: Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo, Norway. johan.ovrevik@fhi.no
authors.forename: Johan
authors.initials: J
authors.lastname: Ovrevik
authors.forename: Magne
authors.initials: M
authors.lastname: Refsnes
authors.forename: Per
authors.initials: P
authors.lastname: Schwarze
authors.forename: Marit
authors.initials: M
authors.lastname: Låg
mesh_terms: D045744:Cell Line, Tumor; D018925:Chemokines / Q000235:genetics*; D016207:Cytokines / Q000235:genetics; D020869:Gene Expression Profiling; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D016209:Interleukin-8 / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D018384:Oxidative Stress; D011791:Quartz / Q000633:toxicity*; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species
chemical_list: D018925:Chemokines; D016207:Cytokines; D016209:Interleukin-8; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D011791:Quartz; D006861:Hydrogen Peroxide