Mammalian sirtuin 1 is involved in the protective action of dietary saturated fat against alcoholic fatty liver in mice

J Nutr. 2008 Mar;138(3):497-501. doi: 10.1093/jn/138.3.497.

Abstract

This study was undertaken to elucidate the mechanism underlying the protective effect of a high saturated fat (HSF) diet against the development of alcoholic fatty liver in mice. We tested the effects of a HSF diet on the ethanol-mediated increase in hepatic sterol regulatory element binding protein 1 (SREBP-1) activity. Thirty-two male mice were divided into 4 groups and fed liquid diets consisting of either a high polyunsaturated fat (40% of energy from corn oil) or a HSF (40% of energy from cocoa butter) diet with or without ethanol for 4 wk. In the ethanol-containing diets, ethanol was substituted for an equivalent amount of carbohydrate to provide 27.5% of the total energy. Control mice were pair-fed the same volume of liquid diets as the ethanol-fed mice. The HSF diet suppressed the increase in mature SREBP-1 protein and prevented increased mRNA of the SREBP-1-regulated lipogenic enzymes in the ethanol-fed mice (P < 0.05). Sirtuins 1 (SIRT1), a NAD+-dependent class III histone deacetylase, was upregulated by ethanol administration in mice fed the HSF diet (P < 0.05). The HSF diet blocked histone H3 at lysine 9 (lys9) hyperacetylation and attenuated association of acetylated histone H3-Lys9 with the promoters of mitochondrial glycerol-3-phosphate acyltransferase and stearoyl-CoA desaturase 1 in the livers of the ethanol-fed mice. These results suggest that the protective effects of HSF diet against the development of alcoholic liver steatosis may occur via regulation of the hepatic SIRT1-SREBP-1-histone H3 axis, suppressing the expression of genes encoding lipogenic enzymes and slowing the synthesis of hepatic fatty acids.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Diet
  • Dietary Fats / pharmacology*
  • Ethanol / adverse effects*
  • Fatty Acids / pharmacology*
  • Fatty Acids, Unsaturated / pharmacology
  • Fatty Liver, Alcoholic / metabolism
  • Fatty Liver, Alcoholic / prevention & control*
  • Gene Expression Regulation / drug effects
  • Histones / metabolism
  • Liver / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Promoter Regions, Genetic
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sirtuin 1
  • Sirtuins / genetics
  • Sirtuins / metabolism*
  • Stearoyl-CoA Desaturase / genetics
  • Stearoyl-CoA Desaturase / metabolism
  • Sterol Regulatory Element Binding Protein 1 / genetics
  • Sterol Regulatory Element Binding Protein 1 / metabolism

Substances

  • Dietary Fats
  • Fatty Acids
  • Fatty Acids, Unsaturated
  • Histones
  • RNA, Messenger
  • Srebf1 protein, mouse
  • Sterol Regulatory Element Binding Protein 1
  • Ethanol
  • Scd1 protein, mouse
  • Stearoyl-CoA Desaturase
  • Sirt1 protein, mouse
  • Sirtuin 1
  • Sirtuins