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Redox factor‐1 mediates NF‐κB nuclear translocation for LPS‐induced iNOS expression in murine macrophage cell line RAW 264.7
Author(s) -
Song Ju Dong,
Lee Sang Kwon,
Kim Kang Mi,
Kim Jong Won,
Kim Jong Min,
Yoo Young Hyun,
Park Young Chul
Publication year - 2008
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2007.02736.x
Subject(s) - chromosomal translocation , nf κb , macrophage , chemistry , redox , microbiology and biotechnology , cell culture , nfkb1 , cancer research , transcription factor , signal transduction , biology , biochemistry , in vitro , gene , genetics , inorganic chemistry
Summary Redox‐sensitive transcriptional regulator redox factor‐1 (Ref‐1) is induced by oxidative stress and protects cells against it. However, the function of Ref‐1 in regulating nitric oxide (NO) synthesis in macrophages has not been defined. We investigated the role of Ref‐1 related to the regulation of NO synthesis in lipopolysaccharide (LPS)‐stimulated macrophage RAW 264.7 cells. LPS stimulates the up‐regulation and nuclear translocation of Ref‐1 in macrophages. Importantly, Ref‐1‐deficient macrophages using a small interfering RNA did not stimulate inducible NO synthase (iNOS) expression as well as nuclear factor‐κB nuclear translocation by stimulation with LPS. When the cells were pretreated with diphenyleneiodonium or p47 phox small interfering RNA for inhibition of NADPH oxidase activity, LPS did not stimulate the nuclear translocation of Ref‐1. We next asked whether reactive oxygen species are sufficient for the nuclear translocation of Ref‐1 in macrophages. The direct use of H 2 O 2 stimulated the translocation to the nucleus of nuclear factor‐κB, but not Ref‐1 and antioxidant N ‐acetyl cysteine did not inhibit the LPS‐stimulated nuclear translocation of Ref‐1. These data suggest that Ref‐1 nuclear translocation in LPS‐stimulated macrophages requires the activation of other signalling molecules aside from reactive oxygen species followed by the activation of NADPH oxidase.