|Title||Industrial Trans Fatty Acids Stimulate SREBP2-Mediated Cholesterogenesis and Promote Non-Alcoholic Fatty Liver Disease|
|Author(s)||Oteng, Antwi Boasiako; Loregger, Anke; Weeghel, Michel van; Zelcer, Noam; Kersten, Sander|
|Source||Molecular Nutrition & Food Research 63 (2019)19. - ISSN 1613-4125|
Nutrition, Metabolism and Genomics
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||cholesterogenesis - cholesterol metabolism - elaidate - non-alcoholic fatty liver disease - sterol regulatory element binding proteins|
Scope: The mechanisms underlying the deleterious effects of trans fatty acids on plasma cholesterol and non-alcoholic fatty liver disease (NAFLD) are unclear. Here, the aim is to investigate the molecular mechanisms of action of industrial trans fatty acids. Methods and results: Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated, or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells shows that elaidate but not oleate or palmitate induces expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate is mediated by increased sterol regulatory element-binding protein 2 (SREBP2) activity and is dependent on SREBP cleavage–activating protein (SCAP), yet independent of liver-X receptor and ubiquitin regulatory X domain-containing protein 8. Elaidate decreases intracellular free cholesterol levels and represses the anticholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increases the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, alanine aminotransferase activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. Conclusion: Elaidate induces cholesterogenesis in vitro by activating the SCAP–SREBP2 axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.