Abstract
We have recently reported that a hypoxia-responsive element (iNOS-HRE) is required for the synergistic activation of the iNOS promoter by hypoxia (1% oxygen) plus IFN-y. To investigate the role of hypoxic conditions in the LPS-dependent induction of iNOS expression, ANA-1 M were stimulated with sub-optimal concentrations of LPS (10 ng/ml) cultured in hypoxic or normoxic (20% oxygen) conditions. We found that hypoxia, although ineffective by itself, caused a significant increase in iNOS mRNA expression induced by LPS alone. ANA-1 M transiently transfected with a plasmid containing the fall-length iNOS promoter linked to a CAT reporter gene expressed significantly higher levels of CAT activity when stimulated with LPS plus hypoxia, versus LPS alone. Deletion of either the iNOS-HRE or the NF-KB consensus sequence from the full-length iNOS promoter caused a dramatic decrease (> 80%) of CAT expression induced by LPS plus hypoxia In contrast, iNOS promoter constructs deleted of the IFN-y-responsive region remained inducible by LPS plus hypoxia. These data demonstrate that hypoxia is a costimulus with LPS for the induction of iNOS expression and they suggest the existence of a cooperative interaction between iNOS-HRE and NF-KB in the regulation of iNOS transcription.
| Original language | English |
|---|---|
| Journal | FASEB Journal |
| Volume | 10 |
| Issue number | 6 |
| Publication status | Published - 1996 |
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ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Cell Biology
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Cooperative interaction between hypoxia and lipopolysaccharide (LPS) in the activation of the inducible nitric oxide synthase (INOS) promoter. / Melillo, G.; Tavlor, L. S.; Brook, A.; Cox, G. W.; Varesio, L.
In: FASEB Journal, Vol. 10, No. 6, 1996.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cooperative interaction between hypoxia and lipopolysaccharide (LPS) in the activation of the inducible nitric oxide synthase (INOS) promoter
AU - Melillo, G.
AU - Tavlor, L. S.
AU - Brook, A.
AU - Cox, G. W.
AU - Varesio, L.
PY - 1996
Y1 - 1996
N2 - We have recently reported that a hypoxia-responsive element (iNOS-HRE) is required for the synergistic activation of the iNOS promoter by hypoxia (1% oxygen) plus IFN-y. To investigate the role of hypoxic conditions in the LPS-dependent induction of iNOS expression, ANA-1 M were stimulated with sub-optimal concentrations of LPS (10 ng/ml) cultured in hypoxic or normoxic (20% oxygen) conditions. We found that hypoxia, although ineffective by itself, caused a significant increase in iNOS mRNA expression induced by LPS alone. ANA-1 M transiently transfected with a plasmid containing the fall-length iNOS promoter linked to a CAT reporter gene expressed significantly higher levels of CAT activity when stimulated with LPS plus hypoxia, versus LPS alone. Deletion of either the iNOS-HRE or the NF-KB consensus sequence from the full-length iNOS promoter caused a dramatic decrease (> 80%) of CAT expression induced by LPS plus hypoxia In contrast, iNOS promoter constructs deleted of the IFN-y-responsive region remained inducible by LPS plus hypoxia. These data demonstrate that hypoxia is a costimulus with LPS for the induction of iNOS expression and they suggest the existence of a cooperative interaction between iNOS-HRE and NF-KB in the regulation of iNOS transcription.
AB - We have recently reported that a hypoxia-responsive element (iNOS-HRE) is required for the synergistic activation of the iNOS promoter by hypoxia (1% oxygen) plus IFN-y. To investigate the role of hypoxic conditions in the LPS-dependent induction of iNOS expression, ANA-1 M were stimulated with sub-optimal concentrations of LPS (10 ng/ml) cultured in hypoxic or normoxic (20% oxygen) conditions. We found that hypoxia, although ineffective by itself, caused a significant increase in iNOS mRNA expression induced by LPS alone. ANA-1 M transiently transfected with a plasmid containing the fall-length iNOS promoter linked to a CAT reporter gene expressed significantly higher levels of CAT activity when stimulated with LPS plus hypoxia, versus LPS alone. Deletion of either the iNOS-HRE or the NF-KB consensus sequence from the full-length iNOS promoter caused a dramatic decrease (> 80%) of CAT expression induced by LPS plus hypoxia In contrast, iNOS promoter constructs deleted of the IFN-y-responsive region remained inducible by LPS plus hypoxia. These data demonstrate that hypoxia is a costimulus with LPS for the induction of iNOS expression and they suggest the existence of a cooperative interaction between iNOS-HRE and NF-KB in the regulation of iNOS transcription.
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M3 - Article
AN - SCOPUS:33749092202
VL - 10
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 6
ER -