Reduced fat mass in rats fed a high oleic acid-rich safflower oil diet is associated with changes in expression of hepatic PPARalpha and adipose SREBP-1c-regulated genes.
PPARs and sterol regulatory element-binding protein-1c (SREPB-1c) are fatty acid-regulated transcription factors that control lipid metabolism at the level of gene expression. This study compared a high oleic acid-rich safflower oil (ORSO) diet and a high-butter diet for their effect on adipose mass and expressions of genes regulated by PPAR and SREPB-1c in rats. Four groups of Wistar rats were fed 30S (30% ORSO), 5S (5% ORSO), 30B (29% butter + 1% ORSO), or 5B (4% butter plus 1% ORSO) diets for 15 wk. Compared with the 30B group, the 30S group had less retroperitoneal white adipose tissue (RWAT) mass and lower mRNA expressions of lipoprotein lipase, adipocyte fatty acid-binding protein, fatty acid synthase, acetyl CoA carboxylase, and SREBP-1c in the RWAT, higher mRNA expressions of acyl CoA oxidase, carnitine palmitoyl-transferase 1A, fatty acid binding protein, and mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase in the liver (P < 0.05). The 18:2(n-6) and 20:4(n-6) contents in the liver and RWAT of the 30S group were >2 fold those of the 30B group (P < 0.05). These results suggested that the smaller RWAT mass in rats fed the high-ORSO diet might be related to the higher tissue 18:2(n-6) and 20:4(n-6). This in turn could upregulate the expressions of fatty acid catabolic genes through the activation of PPARalpha in the liver and downregulate the expressions of lipid storage and lipogenic gene through the suppression of SREBP-1c in the RWAT.
Hsu
Shan-Ching
SC
Division of Nutritional Science, Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan.
Huang
Ching-Jang
CJ
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D020738:Leptin / Q000097:blood; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D019301:Oleic Acid / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D047493:PPAR alpha / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012450:Safflower Oil / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D014280:Triglycerides / Q000097:blood
D004041:Dietary Fats; D020738:Leptin; D047493:PPAR alpha; D051780:Sterol Regulatory Element Binding Protein 1; D014280:Triglycerides; D019301:Oleic Acid; D012450:Safflower Oil