Effects of fish and krill oil on gene expression in peripheral blood mononuclear cells and circulating markers of inflammation: a randomised controlled trial

Abstract

Marine n-3 (omega-3) fatty acids alter gene expression by regulating the activity of transcription factors. Krill oil is a source of marine n-3 fatty acids that has been shown to modulate gene expression in animal studies; however, the effect in humans is not known. Hence, we aimed to compare the effect of intake of krill oil, lean and fatty fish with a similar content of n-3 fatty acids, and high-oleic sunflower oil (HOSO) with added astaxanthin on the expression of genes involved in glucose and lipid metabolism and inflammation in peripheral blood mononuclear cells (PBMC) as well as circulating inflammatory markers. In an 8-week trial, healthy men and women aged 18–70 years with fasting TAG of 1·3–4·0 mmol/l were randomised to receive krill oil capsules (n 12), HOSO capsules (n 12) or lean and fatty fish (n 12). The weekly intakes of marine n-3 fatty acids from the interventions were 4654, 0 and 4103 mg, respectively. The mRNA expression of four genes, PPAR γ coactivator 1A (PPARGC1A), steaoryl-CoA desaturase (SCD), ATP binding cassette A1 (ABCA1) and cluster of differentiation 40 (CD40), were differently altered by the interventions. Furthermore, within-group analyses revealed that krill oil down-regulated the mRNA expression of thirteen genes, including genes involved in glucose and cholesterol metabolism and β-oxidation. Fish altered the mRNA expression of four genes and HOSO down-regulated sixteen genes, including several inflammation-related genes. There were no differences between the groups in circulating inflammatory markers after the intervention. In conclusion, the intake of krill oil and HOSO with added astaxanthin alter the PBMC mRNA expression of more genes than the intake of fish.

Omega-3 Phospholipids from Krill Oil Enhance Intestinal Fatty Acid Oxidation More Effectively than Omega-3 Triacylglycerols in High-Fat Diet-Fed Obese Mice

“…Our transcriptomic analysis used to determine the mechanistic basis of the action of Omega-3 in the small intestine revealed that dietary supplementation with krill oil altered the expression of more genes than fish oil supplying similar amounts of Omega-3. These findings are supported by previous studies suggesting similar superior effects of krill oil on the hepatic transcriptome in mice [50] and on gene expression in peripheral blood mononuclear cells in humans [51]. In the present study, ω3PL-induced DEGs in the small intestine were significantly enriched in 27 GO biological processes, including FAs metabolic processes, intestinal absorption, FAs transport, cholesterol transport, HDL remodeling and glucose metabolism, indicating effective adaptation of the small intestine to lipid overload.…”

Omega-3 fatty acids and leukocyte-endothelium adhesion: Novel anti-atherosclerotic actions

“…Several studies in healthy male and female subjects saw no changes in plasma or serum levels of sICAM-1, sVCAM-1, sE-selectin or sP-selectin with n-3 PUFAs, although some did report reductions. Of those studies which reported sICAM-1 levels after n-3 PUFA supplementation in healthy subjects, the majority reported no changes [69,71,73,75,86,88]. However some studies did see significant decreases [68,70] with only one study reporting a significant increase in serum sICAM-1 levels after supplementation [73].…”

“…Of those studies which reported sICAM-1 levels after n-3 PUFA supplementation in healthy subjects, the majority reported no changes [69,71,73,75,86,88]. However some studies did see significant decreases [68,70] with only one study reporting a significant increase in serum sICAM-1 levels after supplementation [73]. There are also mixed reports from those studies which examined sE-selectin levels after supplementation: the majority of studies reported no changes [68,75,86,88], although some reported significant decreases in healthy adults and children [70,87], whilst one study described an increase [75].…”

Impact of aerobic exercise and fatty acid supplementation on global and gene-specific DNA methylation

“…An emerging mechanism for the anti-inflammatory impact of FA supplementation is via epigenetic modifications [44][45][46][47]. The supplementation of the diet with krill oil, high in n-3 PUFAs, has been demonstrated to reduce PPARGC1A mRNA expression and the change in mRNA expression was negatively correlated to the change in plasma n-3 PUFAs [48]. Total n-3 PUFA content is negatively correlated to both IL6 DNA methylation and IL-6 protein concentration [47].…”