High-protein diets prevent steatosis and induce hepatic accumulation of monomethyl branched-chain fatty acids  Sonia C. Garcia Caraballo, Tine M. Comhair, Sander M. Houten, Cornelis H.C. Dejong, Wouter H. Lamers, S. Eleonore Koehler  Journal of Nutritional Biochemistry  Volume 25, Issue 12, Pages 1263-1274 (December 2014) DOI: 10.1016/j.jnutbio.2014.07.005 Copyright © 2014 Elsevier Inc. Terms and Conditions

Fig. 1 Liver lipids in female mice fed an LF/LP, LF/HP, LF/HP or HF/HP diet for 3 weeks. Panel A shows Oil-Red O (red) and glutamine synthetase (green; pericentral hepatocyte marker) staining of sections of mice on the indicated diets. Note homogeneous distribution of fat in mice on the LF diets and lipid-lowering effect of the HP diets. Scale bar: 0.1 mm. Panel B shows the liver concentration of TGs, FFAs, TC and PLs. Mean±S.E.M. (n=12 per group). Different letters indicate significant differences with P<.05. The diet code of the bars is shown at the bottom. Journal of Nutritional Biochemistry 2014 25, 1263-1274DOI: (10.1016/j.jnutbio.2014.07.005) Copyright © 2014 Elsevier Inc. Terms and Conditions

Fig. 2 Changes in hepatic PUFA composition in female mice fed an LF/LP, LF/HP, LF/HP or HF/HP diet for 3 weeks. The left column shows the hepatic concentration of α-ALA (C18:3n3) and its elongation products EPA (C20:5n3) and DHA (C22:6n3; n3 pathway). The right column shows the hepatic concentration of LA (C18:2n6) and its elongation product AA (C20:4n6; n6 pathway) in mice fed the indicated diets. Mean±S.E.M. (n=6 per group). HP diets decreased EPA and LA (both: P=.001), whereas HF diets increased DHA, LA and AA (all: P≤.001). The diet code of the bars is shown at the bottom. Journal of Nutritional Biochemistry 2014 25, 1263-1274DOI: (10.1016/j.jnutbio.2014.07.005) Copyright © 2014 Elsevier Inc. Terms and Conditions

Fig. 3 Hepatic branched-chain fatty-acid concentrations in female mice fed an LF/LP, LF/HP, LF/HP or HF/HP diet for 3 weeks. Panel A shows the plasma concentration of Leu, Ile, Val and summed BCAAs in mice fed the indicated diets. Panels B and C show the correlations between plasma BCAAs and hepatic TG or Ppargc1α mRNA concentrations, respectively. Panel D depicts the concentration of liver mmBCFAs, while panels E and F depict the correlations between hepatic concentrations of TGs and 14-MPDA or 14-MHDA, respectively. Panels G and H, finally, show the correlations between hepatic Ppargc1a mRNA abundance and mmBCFAs (G) or TG (H) concentrations, respectively. Bars: mean±S.E.M. (n=6–12 per group). The diet code of the bars is shown at the bottom. Journal of Nutritional Biochemistry 2014 25, 1263-1274DOI: (10.1016/j.jnutbio.2014.07.005) Copyright © 2014 Elsevier Inc. Terms and Conditions

Fig. 4 Quantitative PCR analysis of lipid-metabolizing genes in the liver of female mice fed an LF/LP, LF/HP, LF/HP or HF/HP diet for 3 weeks. Panel A shows expression levels of lipogenic genes; panel B, fatty acid-oxidizing genes; and panel C, genes involved in cholesterol metabolism and VLDL export. All values are relative to the LF/LP group (=1). Mean±S.E.M. (n=10 per group). Different letters indicate significant differences with P<.05. The diet code of the bars is shown at the bottom. Journal of Nutritional Biochemistry 2014 25, 1263-1274DOI: (10.1016/j.jnutbio.2014.07.005) Copyright © 2014 Elsevier Inc. Terms and Conditions

Fig. 5 Markers of gluconeogenesis in female mice fed an LF/LP, LF/HP, LF/HP or HF/HP diet for 3 weeks. Panel A shows liver glycogen concentration; panel B, the relative abundance of PCK1 protein, and Pck1 and G6pc mRNAs; and panel C, the plasma glucose concentrations in mice that were either fasted for 4 h or fed ad libitum. Mean±S.E.M. (n=12 per group for mRNA and n=5 for protein concentration). Different letters indicate significant differences with P<.05. The diet code of the bars is shown at the right. Journal of Nutritional Biochemistry 2014 25, 1263-1274DOI: (10.1016/j.jnutbio.2014.07.005) Copyright © 2014 Elsevier Inc. Terms and Conditions

Fig. 6 Markers of inflammation and oxidative stress in female mice fed an LF/LP, LF/HP, LF/HP or HF/HP diet for 3 weeks. Panels A, C and D show mRNA abundance of selected markers of hepatic inflammation (A), Fgf21 mRNA (C) and oxidative stress (D), while panel B shows the phosphorylation state of NFκB protein. All values are relative to LF/LP group (=1). Mean±S.E.M. (n=10 per group). Different letters indicate significant differences with P<.05. The diet code of the bars is shown at the right. Journal of Nutritional Biochemistry 2014 25, 1263-1274DOI: (10.1016/j.jnutbio.2014.07.005) Copyright © 2014 Elsevier Inc. Terms and Conditions