[HTML][HTML] A non-nucleotide–bridged DNA decoy inhibits renal epithelial nitric oxide synthase expression

B Amoah-Apraku, MZ Fang, NJ Guzman - Kidney international, 2000 - Elsevier
B Amoah-Apraku, MZ Fang, NJ Guzman
Kidney international, 2000Elsevier
A non-nucleotide–bridged DNA decoy inhibits renal epithelial nitric oxide synthase
expression. Background The expression of inducible nitric oxide synthase (iNOS) is subject
to strict tissue-specific transcriptional control. In mouse renal epithelium, an interferon-γ (IFN-
γ)-induced signaling protein, IFN-γ regulatory factor 1 (IRF-1), appears to mediate the
induction of iNOS expression by cytokines and bacterial lipopolysaccharide (LPS). Methods
We used a novel technique, namely, blockade of cytosolic IRF-1 activity with a …
A non-nucleotide–bridged DNA decoy inhibits renal epithelial nitric oxide synthase expression.
Background
The expression of inducible nitric oxide synthase (iNOS) is subject to strict tissue-specific transcriptional control. In mouse renal epithelium, an interferon-γ (IFN-γ)-induced signaling protein, IFN-γ regulatory factor 1 (IRF-1), appears to mediate the induction of iNOS expression by cytokines and bacterial lipopolysaccharide (LPS).
Methods
We used a novel technique, namely, blockade of cytosolic IRF-1 activity with a triethyleneglycol-bridged decoy DNA oligonucleotide (ODN) containing the IRF-1 consensus binding sequences present in the iNOS promoter to inhibit iNOS gene expression. Cultured mouse renal epithelial cells were treated with a combination of LPS (1 μg/mL) and IFN (100 U/mL) in the absence or presence of IRF-1 decoy ODN followed by determinations of NO production and iNOS protein and mRNA expression.
Results
Treatment with IRF-1 decoy ODN resulted in concentration-dependent inhibition of NO production and a marked reduction in iNOS protein and mRNA levels. A scrambled ODN failed to affect LPS/IFN-stimulated NO production or iNOS protein and mRNA levels. Transcriptional assays showed that the IRF-1 decoy ODN inhibited transcriptional activity of an iNOS promoter-CAT gene construct.
Conclusions
Decoy ODN-based techniques effectively inhibit iNOS expression in renal epithelium and represent a potentially useful approach for selective blockade of this enzyme in pathologic conditions associated with excessive NO production.
Elsevier