title: Roles of peroxiredoxin II in the regulation of proinflammatory responses to LPS and protection against endotoxin-induced lethal shock.
abstract: Mammalian 2-Cys peroxiredoxin II (Prx II) is a cellular peroxidase that eliminates endogenous H(2)O(2). The involvement of Prx II in the regulation of lipopolysaccharide (LPS) signaling is poorly understood. In this report, we show that LPS induces substantially enhanced inflammatory events, which include the signaling molecules nuclear factor kappaB and mitogen-activated protein kinase (MAPK), in Prx II-deficient macrophages. This effect of LPS was mediated by the robust up-regulation of the reactive oxygen species (ROS)-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and the phosphorylation of p47(phox). Furthermore, challenge with LPS induced greater sensitivity to LPS-induced lethal shock in Prx II-deficient mice than in wild-type mice. Intravenous injection of Prx II-deficient mice with the adenovirus-encoding Prx II gene significantly rescued mice from LPS-induced lethal shock as compared with the injection of a control virus. The administration of catalase mimicked the reversal effects of Prx II on LPS-induced inflammatory responses in Prx II-deficient cells, which suggests that intracellular H(2)O(2) is attributable, at least in part, to the enhanced sensitivity to LPS. These results indicate that Prx II is an essential negative regulator of LPS-induced inflammatory signaling through modulation of ROS synthesis via NADPH oxidase activities and, therefore, is crucial for the prevention of excessive host responses to microbial products.
authors.affiliation: Department of Microbiology, College of Medicine, Chungnam National University, Daejeon 301-747, Korea.
authors.forename: Chul-Su
authors.initials: CS
authors.lastname: Yang
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Lee
authors.forename: Chang-Hwa
authors.initials: CH
authors.lastname: Song
authors.forename: Se-Jin
authors.initials: SJ
authors.lastname: An
authors.forename: Shengjin
authors.initials: S
authors.lastname: Li
authors.forename: Jin-Man
authors.initials: JM
authors.lastname: Kim
authors.forename: Cuk Seong
authors.initials: CS
authors.lastname: Kim
authors.forename: Dae Goon
authors.initials: DG
authors.lastname: Yoo
authors.forename: Byeong Hwa
authors.initials: BH
authors.lastname: Jeon
authors.forename: Hee-Young
authors.initials: HY
authors.lastname: Yang
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Lee
authors.forename: Zee-Won
authors.initials: ZW
authors.lastname: Lee
authors.forename: Jamel
authors.initials: J
authors.lastname: El-Benna
authors.forename: Dae-Yeul
authors.initials: DY
authors.lastname: Yu
authors.forename: Eun-Kyeong
authors.initials: EK
authors.lastname: Jo
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004731:Endotoxins / Q000276:immunology*; D007249:Inflammation / Q000235:genetics / Q000276:immunology; D008070:Lipopolysaccharides / Q000633:toxicity*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010544:Peroxidases / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D054464:Peroxiredoxins; D012769:Shock / Q000235:genetics / Q000276:immunology* / Q000401:mortality / Q000517:prevention & control*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology
chemical_list: D004731:Endotoxins; D008070:Lipopolysaccharides; D010544:Peroxidases; D054464:Peroxiredoxins