title: Dietary moderately oxidized oil induces expression of fibroblast growth factor 21 in the liver of pigs.
abstract: BACKGROUND
  Fibroblast growth factor 21 (FGF21), whose expression is induced by peroxisome proliferator-activated receptor α (PPARα), has been recently identified as a novel metabolic regulator which plays a crucial role in glucose homeostasis, lipid metabolism, insulin sensitivity and obesity. Previous studies have shown that administration of oxidized fats leads to an activation of PPARα in the liver. Therefore, the present study investigated the hypothesis that feeding of oxidized fats causes an induction of FGF21 in the liver.
  
  
  METHODS
  Twenty four crossbred pigs were allocated to two groups of 12 pigs each and fed nutritionally adequate diets with either fresh rapeseed oil or oxidized rapeseed oil prepared by heating at a temperature of 175°C for 72 h.
  
  
  RESULTS
  In pigs fed the oxidized fat mRNA abundance and protein concentrations of FGF21 in liver were significantly increased (P < 0.05), and the protein concentrations of FGF21 in plasma tended to be increased (P < 0.1) in comparison to control pigs. Moreover, pigs fed the oxidized fat had increased transcript levels of the PPARα target genes acyl-CoA oxidase, carnitine palmitoyltransferase-1 and novel organic cation transporter 2 in the liver (P < 0.05), indicative of PPARα activation.
  
  
  CONCLUSIONS
  The present study shows for the first time that administration of an oxidized fat induces the expression of FGF21 in the liver, probably mediated by activation of PPARα. Induction of FGF21 could be involved in several effects observed in animals administered an oxidized fat.
authors.affiliation: Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Varady
authors.forename: Robert
authors.initials: R
authors.lastname: Ringseis
authors.forename: Klaus
authors.initials: K
authors.lastname: Eder
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D019587:Dietary Supplements; D005227:Fatty Acids / Q000737:chemistry; D005229:Fatty Acids, Monounsaturated; D005260:Female; D005346:Fibroblast Growth Factors / Q000235:genetics / Q000378:metabolism*; D015227:Lipid Peroxidation; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D010084:Oxidation-Reduction; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D000074262:Rapeseed Oil; D013482:Superoxide Dismutase / Q000378:metabolism; D013552:Swine; D013974:Thyroxine / Q000097:blood; D024505:Tocopherols / Q000097:blood / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D051267:NF-E2-Related Factor 2; D016328:NF-kappa B; D010938:Plant Oils; D012333:RNA, Messenger; D000074262:Rapeseed Oil; C414620:fibroblast growth factor 21; D005346:Fibroblast Growth Factors; D013482:Superoxide Dismutase; D013974:Thyroxine; D024505:Tocopherols