Prevention and reversal of hepatic steatosis with a high-protein diet in mice

Sonia Garcia Caraballo, Tine M. Comhair, Fons Verheyen, Ingrid Gaemers, Frank G. Schaap, Sander M. Houten, Theodorus B.M. Hakvoort, Cornelis H.C. Dejong, Wouter H. Lamers, S. Eleonore Koehler

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

The hallmark of NAFLD is steatosis of unknown etiology. We tested the effect of a high-protein (HP)22AA: arachidonic acid; Acac: acetyl-CoA carboxylase; Acox: acyl-coenzyme A oxidase; Akt: thymoma viral proto-oncogene 1 (a.k.a. PKB-protein kinase B); Alas1: aminolevulinic acid synthase 1; Arntl (a.k.a. Bmal1): aryl hydrocarbon receptor nuclear translocator-like protein; BCAA: branched-chain amino acids; BHB: β-hydroxybutyrate; ITGAM: Integrin-αM; Chop/Ddit3: C/EBP-homologous protein/DNA damage-inducible transcript 3 protein; Chrebp: carbohydrate-responsive element-binding protein; Cpt1: carnitine palmitoyltransferase 1; DHA: docosahexaenoic acid; eIF2α: eukaryotic translation-initiation factor 2α; Elovl: elongation of very long-chain fatty acids; en%: energy percent; EPA: eicosapentaenoic acid; Fasn: fatty acid synthase; Fgf21: fibroblast growth factor 21; FFA: free fatty acids; G6Pase: glucose-6-phosphatase; GCN2: general control nonrepressed 2; HF: high fat; HF/LPres: high fat, low protein restricted; HP: high protein; LF: low fat; LP: low protein; Mcp1: monocyte chemotactic protein 1; Mlxipl (a.k.a. Chrebp): Mlx-interacting protein-like; mAco: mitochondrial aconitase; mmBCFA: monomethyl branched-chain fatty acid; NAFLD: non-alcoholic fatty liver disease; NASH: non-alcoholic steatohepatitis; Nfil3: nuclear factor interleukin-3-regulated protein; NFκB: nuclear factor κB; Nr1d1 (a.k.a. rev-erbα): nuclear receptor subfamily 1, group D, member 1; PCK1: phosphoenolpyruvate carboxykinase 1; PERK: protein kinase RNA-like endoplasmic reticulum kinase; Pgc1α: pparγ-coactivator1-α, PL: choline-containing phospholipids; Ppar: peroxisome proliferator-activated receptor; rs: Spearman correlation coefficient; Scd1: stearoyl-CoA desaturase 1; Srebf: sterol regulatory element-binding transcription factor; TC: total cholesterol; TG: triglycerides. diet on diet-induced steatosis in male C57BL/6 mice with and without pre-existing fatty liver. Mice were fed all combinations of semisynthetic low-fat (LF) or high-fat (HF) and low-protein (LP) or HP diets for 3weeks. To control for reduced energy intake by HF/HP-fed mice, a pair-fed HF/LP group was included. Reversibility of pre-existing steatosis was investigated by sequentially feeding HF/LP and HF/HP diets. HP-containing diets decreased hepatic lipids to ~40% of corresponding LP-containing diets, were more efficient in this respect than reducing energy intake to 80%, and reversed pre-existing diet-induced steatosis. Compared to LP-containing diets, mice fed HP-containing diets showed increased mitochondrial oxidative capacity (elevated Pgc1α, mAco, and Cpt1 mRNAs, complex-V protein, and decreased plasma free and short-chain acyl-carnitines, and [C0]/[C16+C18] carnitine ratio); increased gluconeogenesis and pyruvate cycling (increased PCK1 protein and fed plasma-glucose concentration without increased G6pase mRNA); reduced fatty-acid desaturation (decreased Scd1 expression and [C16:1n-7]/[C16:0] ratio) and increased long-chain PUFA elongation; a selective increase in plasma branched-chain amino acids; a decrease in cell stress (reduced phosphorylated eIF2α, and Fgf21 and Chop expression); and a trend toward less inflammation (lower Mcp1 and Cd11b expression and less phosphorylated NFκB). Conclusion: HP diets prevent and reverse steatosis independently of fat and carbohydrate intake more efficiently than a 20% reduction in energy intake. The effect appears to result from fuel-generated, highly distributed small, synergistic increases in lipid and BCAA catabolism, and a decrease in cell stress.

Original languageEnglish
Pages (from-to)685-695
Number of pages11
JournalBiochimica et Biophysica Acta - Molecular Basis of Disease
Volume1832
Issue number5
DOIs
Publication statusPublished - 1 May 2013

Keywords

  • Acyl-carnitines
  • ER-stress
  • FGF21
  • High-fat diet
  • NAFLD

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology

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