Effects of DHA-rich n-3 fatty acid supplementation on gene expression in blood mononuclear leukocytes: the OmegAD study

• Published in: PloS one 2012-04, Vol.7 (4), p.e35425
• Main Authors: Vedin, Inger, Cederholm, Tommy, Freund-Levi, Yvonne, Basun, Hans, Garlind, Anita, Irving, Gerd Faxén, Eriksdotter-Jönhagen, Maria, Wahlund, Lars-Olof, Dahlman, Ingrid, Palmblad, Jan
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Alzheimer Disease - diet therapy; Alzheimer Disease - genetics; Alzheimer's disease; Analysis; Biology; Blood; Cardiovascular disease; CD63 antigen; Cytokines; Diet; Dietary Supplements; Disease control; DNA microarrays; Docosahexaenoic acid; Docosahexaenoic Acids - blood; Docosahexaenoic Acids - therapeutic use; Drug dosages; Eicosapentaenoic acid; Eicosapentaenoic Acid - blood; Eicosapentaenoic Acid - therapeutic use; Environmental regulations; Fatty acids; Fatty Acids, Omega-3 - blood; Fatty Acids, Omega-3 - therapeutic use; Female; Fish oils; Gene expression; Gene Expression Regulation; Genes; Genomes; Genomics; Health care; Hospitals; Humans; Inflammation; Leukocytes; Leukocytes (mononuclear); Leukocytes, Mononuclear - metabolism; Male; Medical research; Medicin och hälsovetenskap; Medicine; Neurobiology; Neurodegeneration; Neurodegenerative diseases; Neurosciences; Nutrition research; Oils & fats; Omega 3 fatty acids; Patients; Peripheral blood mononuclear cells; Public health; Rodents; Studies; Transcriptome; Transgenic animals; Transplants & implants; Tumor necrosis factor-TNF; Unsaturated fatty acids; Womens health
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0035425

Dietary fish oil, rich in n-3 fatty acids (n-3 FAs), e.g. docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), regulate inflammatory reactions by various mechanisms, e.g. gene activation. However, the effects of long-term treatment with DHA and EPA in humans, using genome wide techniques, are poorly described. Hence, our aim was to determine the effects of 6 mo of dietary supplementation with an n-3 FA preparation rich in DHA on global gene expression in peripheral blood mononuclear cells. In the present study, blood samples were obtained from a subgroup of 16 patients originating from the randomized double-blind, placebo-controlled OmegAD study, where 174 Alzheimer disease (AD) patients received daily either 1.7 g of DHA and 0.6 g EPA or placebo for 6 months. In blood samples obtained from 11 patients receiving n-3 FA and five placebo, expressions of approximately 8000 genes were assessed by gene array. Significant changes were confirmed by real-time PCR. At 6 months, the n-3 FAs group displayed significant rises of DHA and EPA plasma concentrations, as well as up- and down-regulation of nine and ten genes, respectively, was noticed. Many of these genes are involved in inflammation regulation and neurodegeneration, e.g. CD63, MAN2A1, CASP4, LOC399491, NAIP, and SORL1 and in ubiqutination processes, e.g. ANAPC5 and UBE2V1. Down-regulations of ANAPC5 and RHOB correlated to increases of plasma DHA and EPA levels. We suggest that 6 months of dietary n-3 FA supplementation affected expression of genes that might influence inflammatory processes and could be of significance for AD. ClinicalTrials.gov NCT00211159.