Saturated and monounsaturated fatty acids in membranes are determined by the gene expression of their metabolizing enzymes SCD1 and ELOVL6 regulated by the intake of dietary fat

Eur J Nutr. 2020 Sep;59(6):2759-2769. doi: 10.1007/s00394-019-02121-2. Epub 2019 Nov 1.


Purpose: We investigated the effect of dietary fats on the incorporation of saturated (SAFAs) and monounsaturated dietary fatty acids (MUFAs) into plasma phospholipids and the regulation of the expression of lipid-metabolizing enzymes in the liver.

Methods: Mice were fed different diets containing commonly used dietary fats/oils (coconut fat, margarine, fish oil, sunflower oil, or olive oil) for 4 weeks (n = 6 per diet group). In a second experiment, mice (n = 6 per group) were treated for 7 days with synthetic ligands to activate specific nuclear hormone receptors (NHRs) and the hepatic gene expression of CYP26A1 was investigated. Hepatic gene expression of stearoyl-coenzyme A desaturase 1 (SCD1), elongase 6 (ELOVL6), and CYP26A1 was examined using quantitative real-time PCR (QRT-PCR). Fatty acid composition in mouse plasma phospholipids was analyzed by gas chromatography (GC).

Results: We found significantly reduced hepatic gene expression of SCD1 and ELOVL6 after the fish oil diet compared with the other diets. This resulted in reduced enzyme-specific fatty acid ratios, e.g., 18:1n9/18:0 for SCD1 and 18:0/16:0 and 18:1n7/16:1n7 for ELOVL6 in plasma phospholipids. Furthermore, CYP26A1 a retinoic acid receptor-specific target was revealed as a new player mediating the suppressive effect of fish oil-supplemented diet on SCD1 and ELOVL6 hepatic gene expression.

Conclusion: Plasma levels of MUFAs and SAFAs strongly reflect an altered hepatic fatty acid-metabolizing enzyme expression after supplementation with different dietary fats/oils.

Keywords: Coconut fat; Fish oil; Hepatic gene expression; Margarine; Olive oil; Sunflower oil.

MeSH terms

  • Animals
  • Cell Membrane / chemistry*
  • Dietary Fats*
  • Fatty Acid Elongases* / genetics
  • Fatty Acids / chemistry*
  • Fatty Acids, Monounsaturated / chemistry*
  • Fish Oils
  • Gene Expression
  • Liver
  • Mice
  • Plant Oils
  • Retinoic Acid 4-Hydroxylase
  • Stearoyl-CoA Desaturase* / genetics


  • Dietary Fats
  • Elovl6 protein, mouse
  • Fatty Acids
  • Fatty Acids, Monounsaturated
  • Fish Oils
  • Plant Oils
  • Cyp26a1 protein, mouse
  • Retinoic Acid 4-Hydroxylase
  • Scd1 protein, mouse
  • Stearoyl-CoA Desaturase
  • Fatty Acid Elongases