Biochemical and Biophysical Research Communications
Oxidative stress reduces histone deacetylase 2 activity and enhances IL-8 gene expression: role of tyrosine nitration
Section snippets
Materials and methods
Materials. Thirty percentage of H2O2 and N-acetyl-l-cysteine (NAC) were purchased from Sigma (Sigma, Poole, UK); IL-1β was from R&D (Abingdon, UK); DCFH-DA and SIN-1 were from Molecular Probes (Leiden, Netherlands); and peroxynitrite was from Cayman Chemicals (Ann Arbor, MI, USA). Anti-p65 (sc-109, sc-7151), anti-phosphotyrosine (sc-508), anti-HDAC2 (sc-7899), and anti-HDAC1 (sc-6298) antibodies were obtained from Santa Cruz Biotec (Santa Cruz, California, USA), and anti-nitrotyrosine (1A6) was
H2O2 enhances IL-1β-stimulated cytokine expression
Pretreatment of human airway epithelial cells (BEAS2B) with H2O2 (100 μM) for 4 h slightly enhanced basal IL-8 production but markedly potentiated IL-1β-stimulated IL-8 production (2497 ± 226 ng/ml versus 1066 ± 64) (Fig. 1A) without affecting cell survival (data not shown). This enhancement by pretreatment of H2O2 was maximal at 4 h (Fig. 1B). Four hour pretreatment of H2O2 also enhanced GM-CSF production as well as IL-8 (211 ± 22 vs 138 ± 36). This effect was blocked by the anti-oxidant N-acetyl-l
Discussion
In this study we have demonstrated that H2O2 and peroxynitrite enhanced IL-1β-induced expression of inflammatory cytokines, such as GM-CSF and IL-8. This effect could be blocked by the anti-oxidant NAC. Using chromatin immunoprecipitation assays in cells treated with IL-1β plus H2O2, the IL-8 promoter region was associated with much greater levels of acetylated histone H4 than those after IL-1β stimulation alone. Under the same conditions, there was no change in p65-associated IL-8 promoter
Acknowledgements
This work was funded by the British Lung Foundation, the Clinical Research Committee (Royal Brompton Hospital), and GlaxoSmithKline plc (UK).
References (23)
- et al.
Chem. Biol. Interact.
(1994) - et al.
J. Biol. Chem.
(1998) - et al.
Cell
(1996) - et al.
J. Biol. Chem.
(2001) - et al.
Mol. Cell
(2002) - et al.
Free Radic. Biol. Med.
(1999) - et al.
J. Biol. Chem.
(1998) - et al.
J. Biol. Chem.
(2001) - et al.
Biochem. Biophys. Res. Commun.
(1994) J. Am. Coll. Nutr.
(1995)