Retinoic acid inhibits inducible nitric oxide synthase expression in 3T3-L1 adipocytes
Experimental & Molecular Medicine
;
: 353-360, 2002.
Article
in English
| WPRIM
| ID: wpr-203701
ABSTRACT
The present study was undertaken to explore whether retinoids, which are known to have immunomodulatory actions, could attenuate tumor necrosis factor-alpha (TNF)-stimulated inducible nitric oxide synthase (iNOS) expression in 3T3-L1 adipocytes. Adipocytes incubated with TNF induced dose- and time-dependent accumulation of nitrite in the culture medium through the iNOS induction as confirmed by Western blotting. Treatment of cells with TNF in the presence of all-trans-retinoic acid (RA) significantly decreased their ability to produce nitrite and iNOS induction. Both 13-cis- and all- trans-RA-induced suppression was dose-dependent, and all-trans-RA was somewhat potent than 13-cis-RA. The inhibitory effect of RA on TNF-induced iNOS induction was reversible, completely recovered after 2 days, and was exerted through the inhibition of NF-kappaB activation. TNF also suppressed the lipoprotein lipase (LPL) activity of 3T3-L1 adipocytes. RA could not reverse the TNF- induced LPL suppression at RA levels causing near complete inhibition of the TNF-induced NO production. These results indicate that RAs attenuate iNOS expression reversibly in TNF-stimulated 3T3-L1 adipocytes, and that the TNF- induced LPL suppression is not the result of NO overproduction.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Tretinoin
/
Cells, Cultured
/
Enzyme Induction
/
NF-kappa B
/
Tumor Necrosis Factor-alpha
/
3T3 Cells
/
Adipocytes
/
Nitric Oxide Synthase
/
Enzyme Inhibitors
/
Lipoprotein Lipase
Limits:
Animals
Language:
English
Journal:
Experimental & Molecular Medicine
Year:
2002
Type:
Article
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