title: Adipose tissue transcriptional response of lipid metabolism genes in growing Iberian pigs fed oleic acid v. carbohydrate enriched diets.
abstract: Diet influences animal body and tissue composition due to direct deposition and to the nutrients effects on metabolism. The influence of specific nutrients on the molecular regulation of lipogenesis is not well characterized and is known to be influenced by many factors including timing and physiological status. A trial was performed to study the effects of different dietary energy sources on lipogenic genes transcription in ham adipose tissue of Iberian pigs, at different growth periods and on feeding/fasting situations. A total of 27 Iberian male pigs of 28 kg BW were allocated to two separate groups and fed with different isocaloric feeding regimens: standard diet with carbohydrates as energy source (CH) or diet enriched with high oleic sunflower oil (HO). Ham subcutaneous adipose tissue was sampled by biopsy at growing (44 kg mean BW) and finishing (100 kg mean BW) periods. The first sampling was performed on fasted animals, while the last sampling was performed twice, with animals fasted overnight and 3 h after refeeding. Effects of diet, growth period and feeding/fasting status on gene expression were explored quantifying the expression of a panel of key genes implicated in lipogenesis and lipid metabolism processes. Quantitative PCR revealed several differentially expressed genes according to diet, with similar results at both timings: RXRG, LEP and FABP5 genes were upregulated in HO group while ME1, FASN, ACACA and ELOVL6 were upregulated in CH. The diet effect on ME1 gene expression was conditional on feeding/fasting status, with the higher ME1 gene expression in CH than HO groups, observed only in fasting samples. Results are compatible with a higher de novo endogenous synthesis of fatty acids (FA) in the carbohydrate-supplemented group and a higher FA transport in the oleic acid-supplemented group. Growth period significantly affected the expression of most of the studied genes, with all but PPARG showing higher expression in finishing pigs according to a pattern dissimilar from the usual in cosmopolitan pig breeds. Feeding/fasting status only influenced PPARG gene transcription. The lack of effects of feeding/fasting status on lipogenic gene expression and the higher ME1 response to diet in fasting samples than in postprandial sampling, suggest the persistence of de novo lipogenesis during fasting. Overall results improve the understanding of the influence of different factors on lipid metabolism regulation in Iberian pigs.
authors.affiliation: 1Departamento Mejora Genética Animal,INIA,Ctra. Coruña Km 7.5,28040 Madrid,Spain.
authors.forename: R
authors.initials: R
authors.lastname: Benítez
authors.affiliation: 1Departamento Mejora Genética Animal,INIA,Ctra. Coruña Km 7.5,28040 Madrid,Spain.
authors.forename: Y
authors.initials: Y
authors.lastname: Núñez
authors.affiliation: 1Departamento Mejora Genética Animal,INIA,Ctra. Coruña Km 7.5,28040 Madrid,Spain.
authors.forename: A
authors.initials: A
authors.lastname: Fernández
authors.affiliation: 2Departamento Producción Animal, Facultad de Veterinaria,UCM,28040 Madrid,Spain.
authors.forename: B
authors.initials: B
authors.lastname: Isabel
authors.affiliation: 1Departamento Mejora Genética Animal,INIA,Ctra. Coruña Km 7.5,28040 Madrid,Spain.
authors.forename: C
authors.initials: C
authors.lastname: Rodríguez
authors.affiliation: 3Departamento de Producción Animal,Escuela Técnica Superior de Ingenieros Agrónomos,UPM,28040 Madrid,Spain.
authors.forename: A
authors.initials: A
authors.lastname: Daza
authors.affiliation: 2Departamento Producción Animal, Facultad de Veterinaria,UCM,28040 Madrid,Spain.
authors.forename: C
authors.initials: C
authors.lastname: López-Bote
authors.affiliation: 1Departamento Mejora Genética Animal,INIA,Ctra. Coruña Km 7.5,28040 Madrid,Spain.
authors.forename: L
authors.initials: L
authors.lastname: Silió
authors.affiliation: 1Departamento Mejora Genética Animal,INIA,Ctra. Coruña Km 7.5,28040 Madrid,Spain.
authors.forename: C
authors.initials: C
authors.lastname: Óvilo
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D004032:Diet / Q000662:veterinary; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D019587:Dietary Supplements; D005227:Fatty Acids / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects* / Q000235:genetics*; D050155:Lipogenesis / Q000187:drug effects / Q000235:genetics; D008297:Male; D019301:Oleic Acid / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology; D050151:Subcutaneous Fat / Q000378:metabolism; D000074242:Sunflower Oil; D013552:Swine / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D004040:Dietary Carbohydrates; D005227:Fatty Acids; D010938:Plant Oils; D000074242:Sunflower Oil; D019301:Oleic Acid
keywords: Iberian pig; adipose tissue; dietary oleic acid; gene expression; lipid metabolism