title: NF-kappa B inhibition by omega -3 fatty acids modulates LPS-stimulated macrophage TNF-alpha transcription.
abstract: Omega-3 fatty acid (FA) emulsions reduce LPS-stimulated murine macrophage TNF-alpha production, but the exact mechanism has yet to be defined. The purpose of this study was to determine the mechanism for omega-3 FA inhibition of macrophage TNF-alpha production following LPS stimulation. RAW 264.7 cells were pretreated with isocaloric emulsions of omega-3 FA (Omegaven), omega-6 FA (Lipovenos), or DMEM and subsequently exposed to LPS. IkappaB-alpha and phospho-IkappaB-alpha were determined by Western blotting. NF-kappaB binding was assessed using the electromobility shift assay, and activity was measured using a luciferase reporter vector. RT-PCR and ELISA quantified TNF-alpha mRNA and protein levels, respectively. Pretreatment with omega-3 FA inhibited IkappaB phosphorylation and significantly decreased NF-kappaB activity. Moreover, omega-3-treated cells demonstrated significant decreases in both TNF-alpha mRNA and protein expression by 47 and 46%, respectively. These experiments demonstrate that a mechanism for proinflammatory cytokine inhibition in murine macrophages by omega-3 FA is mediated, in part, through inactivation of the NF-kappaB signal transduction pathway secondary to inhibition of IkappaB phosphorylation.
authors.affiliation: Laboratories of Surgical Metabolism, University of Illinois at Chicago, 840 South Wood Street, Chicago, IL 60612, USA.
authors.forename: Todd E
authors.initials: TE
authors.lastname: Novak
authors.forename: Tricia A
authors.initials: TA
authors.lastname: Babcock
authors.forename: David H
authors.initials: DH
authors.lastname: Jho
authors.forename: W Scott
authors.initials: WS
authors.lastname: Helton
authors.forename: N Joseph
authors.initials: NJ
authors.lastname: Espat
mesh_terms: D000818:Animals; D002460:Cell Line; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D020672:I-kappa B Proteins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D015525:Fatty Acids, Omega-3; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha