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Updated: Jul 19, 2026
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Enzymatic Synthesis of Epoxidized Metabolites of Docosahexaenoic, Eicosapentaenoic, and Arachidonic Acids
Published on: June 28, 2019
Trans geometric isomers of EPA decrease LXRalpha-induced cellular triacylglycerol via suppression of SREBP-1c and
Nobuhiro Zaima1, Tatsuya Sugawara, Dai Goto
1Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Journal of Lipid Research
|September 29, 2006
Summary
Trans isomers of eicosapentaenoic acid (TEPA) reduce cellular triacylglycerol synthesis and gene expression in liver cells. TEPA
Area of Science:
- Lipid Metabolism
- Molecular Biology
- Cardiovascular Disease Research
Background:
- Dietary trans fatty acids (18-22 carbons) elevate cardiovascular disease risk by altering LDL and HDL cholesterol.
- The impact of trans isomers of polyunsaturated fatty acids (PUFAs) on lipid metabolism is largely unknown.
- Dietary PUFAs, like eicosapentaenoic acid (EPA), can improve lipid profiles by inhibiting liver X receptor alpha (LXRα).
Purpose of the Study:
- To investigate the effects of trans eicosapentaenoic acid (TEPA) on triacylglycerol synthesis.
- To compare TEPA's effects with EPA on lipid metabolism pathways.
- To elucidate the molecular mechanisms underlying TEPA's potential hypolipidemic effects.
Main Methods:
- Utilized HepG2 cells treated with a synthetic LXRα agonist (T0901317).
- Assessed cellular triacylglycerol levels and mRNA expression of key lipogenic genes.
- Compared the effects of TEPA and EPA on gene expression, including sterol-regulatory element binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor gamma coactivator 1beta (PGC-1β).
Main Results:
- TEPA significantly reduced cellular triacylglycerol accumulation induced by T0901317.
- TEPA suppressed the mRNA expression of fatty acid synthase, stearoyl-CoA desaturase-1, and glycerol-3-phosphate acyltransferase more effectively than EPA.
- TEPA, unlike EPA, significantly decreased the mRNA expression of PGC-1β, a coactivator of LXRα and SREBP-1.
Conclusions:
- TEPA exhibits hypolipidemic effects by reducing triacylglycerol synthesis in liver cells.
- TEPA's lipid-lowering mechanism involves downregulation of SREBP-1 and PGC-1β expression.
- TEPA may represent a beneficial dietary component for managing lipid metabolism, distinct from its cis isomer, EPA.
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