Anti-inflammatory effects of EPA and DHA are dependent upon time and dose-response elements associated with LPS stimulation in THP-1-derived macrophages.
The long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) of fish oil, eicosapentanoic (EPA) and docosahexanoic (DHA) acids are considered cardioprotective. Inflammation elicited by macrophages is increasingly recognised in the aetiology of metabolic syndrome. This study investigated the differential anti-inflammatory potential of EPA and DHA through cytokine production and nuclear factor (NF)-kappaB signalling in a human macrophage model. We investigated the dependency of LC n-3 PUFA immune-modulation on concentration and duration of lipopolysaccharide (LPS) activation. Interleukin (IL)-1beta, IL-6 and tumor necrosis factor-alpha secretion from EPA, DHA and control cells were differentially limited by LPS concentration. In all cases, there was no benefit in activating cells with >0.1 microg/ml LPS. LC n-3 PUFA decreased proinflammatory cytokines production, an effect modulated by LPS concentration. Expression of the transcription factor NF-kappaB p65 was significantly reduced in the nucleus and retained in the cytoplasm of EPA- and/or DHA-treated macrophages during 5-h activation with 0.1 microg/ml LPS. Nuclear binding of p65 was significantly reduced in EPA- and DHA-treated cells at 2-h LPS activation. Over the time course, expression of nuclear IkappaBalpha was significantly reduced, cytoplasmic NF-kappaB p50 significantly increased and cytoplasmic cleaving enzyme IkappaB inhibitor complex significantly reduced in LC n-3 PUFA-treated cells. EPA and DHA down-regulated the production of proinflammatory cytokines associated with the aetiology of metabolic syndrome, NF-kappaB transcriptional activity and upstream cytoplasmic signalling events. Immune responses are dynamic, and the present study suggests a nutrient sensitive window of LPS activation at which EPA and DHA are strongly anti-inflammatory.
UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
Anne
A
Mullen
Christine E
CE
Loscher
Helen M
HM
Roche
D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D002316:Cardiotonic Agents / Q000008:administration & dosage*; D002460:Cell Line; D004281:Docosahexaenoic Acids / Q000008:administration & dosage*; D015536:Down-Regulation; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage*; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D020672:I-kappa B Proteins / Q000378:metabolism; D056747:Immunomodulation; D007249:Inflammation / Q000150:complications; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation; D008264:Macrophages / Q000166:cytology / Q000502:physiology*; D024821:Metabolic Syndrome / Q000209:etiology; D000072000:NF-KappaB Inhibitor alpha; D052002:NF-kappa B p50 Subunit / Q000378:metabolism; D021381:Protein Transport; D015398:Signal Transduction; D013997:Time Factors; D051996:Transcription Factor RelA / Q000378:metabolism
D000893:Anti-Inflammatory Agents; D002316:Cardiotonic Agents; D020672:I-kappa B Proteins; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D052002:NF-kappa B p50 Subunit; C000606204:NFKBIA protein, human; D051996:Transcription Factor RelA; D000072000:NF-KappaB Inhibitor alpha; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D051550:I-kappa B Kinase