title: De novo lipogenesis in Atlantic salmon adipocytes.
abstract: BACKGROUND
  Carnivorous teleost fish utilize glucose poorly, and the reason for this is not known. It is possible that the capacity of adipocytes to synthesize lipids from carbohydrate precursors through a process known as "de novo lipogenesis" (DNL) is one of the factors that contributes to glucose intolerance in Atlantic salmon.
  
  
  METHODS
  Primary adipocytes from Atlantic salmon differentiated in vitro were incubated with radiolabelled glucose in order to explore the capacity of salmon adipocytes to synthesize and deposit lipids from glucose through DNL. The lipid-storage capacity of adipocytes incubated with glucose was compared with that of cells incubated with the fatty acid palmitic acid. Quantitative PCR and immunohistochemistry were used to assess changes of genes and proteins involved in glucose and lipid transport and metabolism.
  
  
  RESULTS
  Less than 0.1% of the radiolabelled glucose was metabolized to the fatty acids 16:0 and the stearoyl-CoA desaturase products 16:1 and 18:1 by DNL, whereas approximately 40% was converted to glycerol to form the triacylglycerol backbone of lipids. Transcriptional analysis indicated that adipocytes ensure the availability of necessary cofactors and other substrates for lipid synthesis and storage from glycolysis, the pentose phosphate pathway and glyceroneogenesis.
  
  
  CONCLUSIONS
  We have shown for the first time that the DNL pathway is active in fish adipocytes. The capacity of the pathway to convert glucose into cellular lipids for storage is relatively low.
  
  
  CONCLUSIONS
  The limited capacity of adipocytes to utilize glucose as a substrate for lipid deposition may contribute to glucose intolerance in salmonids.
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Barcelona 08028, Spain; Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, NO-1431 Ås, Norway. Electronic address: marta.bou@nofima.no.
authors.forename: Marta
authors.initials: M
authors.lastname: Bou
authors.affiliation: Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, NO-1431 Ås, Norway.
authors.forename: Marijana
authors.initials: M
authors.lastname: Todorčević
authors.affiliation: Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, NO-1431 Ås, Norway.
authors.forename: Jacob
authors.initials: J
authors.lastname: Torgersen
authors.affiliation: Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, NO-1431 Ås, Norway.
authors.forename: Stanko
authors.initials: S
authors.lastname: Škugor
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Barcelona 08028, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Navarro
authors.affiliation: Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, NO-1431 Ås, Norway.
authors.forename: Bente
authors.initials: B
authors.lastname: Ruyter
mesh_terms: D017667:Adipocytes / Q000378:metabolism*; D000818:Animals; D050612:Fatty Acid Transport Proteins / Q000502:physiology; D005947:Glucose / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000502:physiology; D050356:Lipid Metabolism; D050155:Lipogenesis; D019308:Palmitic Acid / Q000378:metabolism; D020317:Salmo salar; D014280:Triglycerides / Q000096:biosynthesis
chemical_list: D050612:Fatty Acid Transport Proteins; D051275:Glucose Transporter Type 4; D014280:Triglycerides; D019308:Palmitic Acid; D005947:Glucose
keywords: Adipose tissue; Differentiation; Glucose metabolism; Palmitic acid; Teleost