Lipid remodeling and an altered membrane-associated proteome may drive the differential effects of EPA and DHA treatment on skeletal muscle glucose uptake and protein accretion

• Published in: American journal of physiology: endocrinology and metabolism Vol. 314; no. 6; pp. E605 - E619
• Main Authors: Jeromson, Stewart, Mackenzie, Ivor, Doherty, Mary K, Whitfield, Phillip D, Bell, Gordon, Dick, James, Shaw, Andy, Rao, Francesco V, Ashcroft, Stephen P, Philp, Andrew, Galloway, Stuart D R, Gallagher, Iain, Hamilton, D Lee
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.06.2018
• Subjects: Accretion; Amino acids; Animals; Arachidonic acid; Carbohydrate Metabolism - drug effects; Cell culture; Cell Membrane - drug effects; Cell Membrane - metabolism; Cells, Cultured; Chains; Deposition; Divergence; Docosahexaenoic acid; Docosahexaenoic Acids - pharmacology; Eicosapentaenoic acid; Eicosapentaenoic Acid - analogs & derivatives; Eicosapentaenoic Acid - pharmacology; Esters; Fatty acid methyl esters; Fatty acids; Fatty Acids - metabolism; Glucose; Glucose - metabolism; Lipid Metabolism - drug effects; Lipids; Membrane Proteins - drug effects; Membrane Proteins - metabolism; Metabolism; Mice; Muscle function; Muscle, Skeletal - drug effects; Muscle, Skeletal - metabolism; Muscles; Myotubes; Phospholipids; Protein turnover; Proteins; Proteome - drug effects; Proteome - metabolism; Proteomics; Skeletal muscle; Stable isotopes; Triglycerides - metabolism; fatty acid; lipids; insulin; lipidomics; cell signaling; fish oil
• ISSN: 0193-1849; 1522-1555
• DOI: 10.1152/ajpendo.00438.2015

In striated muscle, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have differential effects on the metabolism of glucose and differential effects on the metabolism of protein. We have shown that, despite similar incorporation, treatment of C C myotubes (CM) with EPA but not DHA improves glucose uptake and protein accretion. We hypothesized that these differential effects of EPA and DHA may be due to divergent shifts in lipidomic profiles leading to altered proteomic profiles. We therefore carried out an assessment of the impact of treating CM with EPA and DHA on lipidomic and proteomic profiles. Fatty acid methyl esters (FAME) analysis revealed that both EPA and DHA led to similar but substantials changes in fatty acid profiles with the exception of arachidonic acid, which was decreased only by DHA, and docosapentanoic acid (DPA), which was increased only by EPA treatment. Global lipidomic analysis showed that EPA and DHA induced large alterations in the cellular lipid profiles and in particular, the phospholipid classes. Subsequent targeted analysis confirmed that the most differentially regulated species were phosphatidylcholines and phosphatidylethanolamines containing long-chain fatty acids with five (EPA treatment) or six (DHA treatment) double bonds. As these are typically membrane-associated lipid species we hypothesized that these treatments differentially altered the membrane-associated proteome. Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics of the membrane fraction revealed significant divergence in the effects of EPA and DHA on the membrane-associated proteome. We conclude that the EPA-specific increase in polyunsaturated long-chain fatty acids in the phospholipid fraction is associated with an altered membrane-associated proteome and these may be critical events in the metabolic remodeling induced by EPA treatment.