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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Animals, Cell Line, Cell Membrane, Eicosapentaenoic Acid, Escherichia coli, Fatty Acids, Fish Oils, Lipopolysaccharides, Macrophages, Mice, NF-kappa B, RNA, Messenger, Transcription, Genetic, Tumor Necrosis Factor-alpha.
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Does fish oil decrease macrophage tumor necrosis factor gene transcription by altering the NF kappa B activity? Context: Fish oil-supplemented diets have anti-inflammatory and immunomodulating effects, though the exact mechanism(s) are unknown. This study investigated the effects of eicosapentanenoic acid (EPA), a major component of fish oil, on transcriptional regulation of tumor necrosis factor (TNF) gene in lipopolysaccharide (LPS)-stimulated macrophages (MO). RAW 264.7 cells, a mouse MO cell line, were grown in EPA-rich media for 24-48 h. MO were washed and exposed to Escherichia coli LPS (1 microg/ml) for 2 h. TNF mRNA expression was measured by Northern blot assays. Total nuclear extracts were harvested for the measurement of NF kappa B with electrophoretic mobility shift assays. Supershift assays were performed with anti-P50 or anti-P65 antibodies to show components of NF kappa B dimers. TNF production was determined by L929 bioassays. LPS stimulated RAW cell TNF mRNA expression and NF kappa B activity. In contrast, RAW cells grown in EPA-rich media had less TNF mRNA expression and an altered composition of the NF kappa B subunits (P65/P50 dimers) in the presence of LPS. TNF production by LPS-stimulated MO was reduced by EPA.
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The inhibitory effect of EPA on LPS-stimulated MO TNF gene transcription and protein elaboration is, in part, mediated through altering NF kappa B activation by reducing the P65/P50 dimers. Final Decision: yes