title: Feeding rainbow trout with a lipid-enriched diet: effects on fatty acid sensing, regulation of food intake and cellular signaling pathways.
abstract: Using rainbow trout fed with low-fat or high-fat diets, we aimed to determine whether the response of food intake, mRNA abundance of hypothalamic neuropeptides involved in the metabolic regulation of food intake and fatty acid sensing systems in the hypothalamus and liver are similar to results previously observed when levels of specific fatty acids were raised by injection. Moreover, we also aimed to determine if the phosphorylation state of intracellular energy sensor 5'-AMP-activated protein kinase (AMPK), and proteins involved in cellular signaling such as protein kinase B (Akt) and target of rapamycin (mTOR) display changes that could be related to fatty acid sensing and the control of food intake. The increased levels of fatty acids in the hypothalamus and liver of rainbow trout fed with a high-fat diet only partially activated fatty acid sensing systems and did not elicit changes in food intake, suggesting that the fatty acid sensing response in fish is more dependent on the presence of specific fatty acids, such as oleate or octanoate, rather than to the global increase in fatty acids. We also obtained, for the first time in fish, evidence for the presence and function of energy sensors such as AMPK and proteins involved in cellular signaling, like mTOR and Akt, in the hypothalamus. These proteins in the hypothalamus and liver were generally activated in fish fed the high-fat versus low-fat diet, suggesting that cellular signaling pathways are activated in response to the increased availability of fatty acids.
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Librán-Pérez
authors.affiliation: INRA, UR 1067 Nutrition Metabolism Aquaculture, Aquapôle, CD918, St-Pée-sur-Nivelle F-64310, France.
authors.forename: Inge
authors.initials: I
authors.lastname: Geurden
authors.affiliation: INRA, UR 1067 Nutrition Metabolism Aquaculture, Aquapôle, CD918, St-Pée-sur-Nivelle F-64310, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Dias
authors.affiliation: INRA, UR 1067 Nutrition Metabolism Aquaculture, Aquapôle, CD918, St-Pée-sur-Nivelle F-64310, France.
authors.forename: Genevieve
authors.initials: G
authors.lastname: Corraze
authors.affiliation: INRA, UR 1067 Nutrition Metabolism Aquaculture, Aquapôle, CD918, St-Pée-sur-Nivelle F-64310, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Panserat
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain jsoengas@uvigo.es.
authors.forename: José L
authors.initials: JL
authors.lastname: Soengas
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000818:Animals; D004041:Dietary Fats / Q000378:metabolism*; D004435:Eating / Q000502:physiology*; D005227:Fatty Acids / Q000378:metabolism; D029941:Fish Proteins / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D029941:Fish Proteins; D009479:Neuropeptides; D012333:RNA, Messenger; D055372:AMP-Activated Protein Kinases
keywords: AMPK; Akt; Fatty acid sensing; Lipid-enriched diet; Rainbow trout; mTOR