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Integration of insulin and amino acid signals that regulate hepatic metabolism-related gene expression in rainbow trout: role of TOR

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Abstract

Amino acids are considered to be regulators of metabolism in several species, and increasing importance has been accorded to the role of amino acids as signalling molecules regulating protein synthesis through the activation of the TOR transduction pathway. Using rainbow trout hepatocytes, we examined the ability of amino acids to regulate hepatic metabolism-related gene expression either alone or together with insulin, and the possible involvement of TOR. We demonstrated that amino acids alone regulate expression of several genes, including glucose-6-phosphatase, phosphoenolpyruvate carboxykinase, pyruvate kinase, 6-phospho-fructo-1-kinase and serine dehydratase, through an unknown molecular pathway that is independent of TOR activation. When insulin and amino acids were added together, a different pattern of regulation was observed that depended upon activation of the TOR pathway. This pattern included a dramatic up-regulation of lipogenic (fatty acid synthase, ATP-citrate lyase and sterol responsive element binding protein 1) and glycolytic (glucokinase, 6-phospho-fructo-1-kinase and pyruvate kinase) genes in a TOR-dependent manner. Regarding gluconeogenesis genes, only glucose-6-phosphatase was inhibited in a TOR-dependent manner by combination of insulin and amino acids and not by amino acids alone. This study is the first to demonstrate an important role of amino acids in combination with insulin in the molecular regulation of hepatic metabolism.

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References

  • Alam N, Saggerson ED (1998) Malonyl-CoA and the regulation of fatty acid oxidation in soleus muscle. Biochem J 334:233–241

    CAS  PubMed  Google Scholar 

  • Avruch J, Long X, Ortiz-Vega S, Rapley J, Papageorgiou A, Dai N (2009) Amino acid regulation of TOR complex 1. Am J Physiol Endocrinol Metab 296:E592–E602

    Article  CAS  PubMed  Google Scholar 

  • Barbosa-Tessmann IP, Chen C, Zhong C, Siu F, Schuster SM, Nick HS, Kilberg MS (2000) Activation of the human asparagine synthetase gene by the amino acid response and the endoplasmic reticulum stress response pathways occurs by common genomic elements. J Biol Chem 275:26976–26985

    CAS  PubMed  Google Scholar 

  • Barthel A, Schmoll D (2003) Novel concepts in insulin regulation of hepatic gluconeogenesis. Am J Physiol 285:E685–E692

    CAS  Google Scholar 

  • Committee on Animal Nutrition, Board of Agriculture, National Research Council (1993) Nutrient requirements of fish. National Academy Press, Washington, DC

    Google Scholar 

  • del sol Novoa M, Capilla E, Rojas P, Baro J, Gutierrez J, Navarro I (2004) Glucagon and insulin response to dietary carbohydrate in rainbow trout (Oncorhynchus mykiss). Gen Comp Endocrinol 139:48–54

    Article  CAS  PubMed  Google Scholar 

  • Ferraris M, Radice S, Catalani P, Francolini M, Marabini L, Chiesara E (2002) Early oxidative damage in primary cultured trout hepatocytes: a time course study. Aquat Toxicol 59:283–296

    Article  CAS  PubMed  Google Scholar 

  • Gong SS, Guerrini L, Basilico C (1991) Regulation of asparagine synthetase gene expression by amino acid starvation. Mol Cell Biol 11:6059–6066

    CAS  PubMed  Google Scholar 

  • Goswami C, Datta S, Biswas K, Saha N (2004) Cell volume changes affect gluconeogenesis in the perfused liver of the catfish Clarias batrachus. J Biosci 29:337–347

    Article  CAS  PubMed  Google Scholar 

  • Guerrini L, Gong SS, Mangasarian K, Basilico C (1993) Cis- and trans-acting elements involved in amino acid regulation of asparagine synthetase gene expression. Mol Cell Biol 13:3202–3212

    CAS  PubMed  Google Scholar 

  • Ishikawa E, Ninagawa T, Suda M (1965) Hormonal and dietary control of serine dehydratase in rat liver. J Biochem 57:506–513

    CAS  PubMed  Google Scholar 

  • Jobgen WS, Fried SK, Fu WJ, Meininger CJ, Wu G (2006) Regulatory role for the arginine-nitric oxide pathway in metabolism of energy substrates. J Nutr Biochem 17:571–588

    Article  CAS  PubMed  Google Scholar 

  • Jousse C, Averous J, Bruhat A, Carraro V, Mordier S, Fafournoux P (2004) Amino acids as regulators of gene expression: molecular mechanisms. Biochem Biophys Res Commun 313:447–452

    Article  CAS  PubMed  Google Scholar 

  • Kimball SR, Jefferson LS (2006) Signaling pathways and molecular mechanisms through which branched-chain amino acids mediate translational control of protein synthesis. J Nutr 136:227S–231S

    CAS  PubMed  Google Scholar 

  • Kirchner S, Kaushik S, Panserat S (2003) Low protein intake is associated with reduced hepatic gluconeogenic enzyme expression in rainbow trout (Oncorhynchus mykiss). J Nutr 133:2561–2564

    CAS  PubMed  Google Scholar 

  • Liao J, Barthel A, Nakatani K, Roth RA (1998) Activation of protein kinase B/Akt is sufficient to repress the glucocorticoid and cAMP induction of phosphoenolpyruvate carboxykinase gene. J Biol Chem 273:27320–27324

    Article  CAS  PubMed  Google Scholar 

  • Meijer AJ (2003) Amino acids as regulators and components of nonproteinogenic pathways. J Nutr 133:2057S–2062S

    CAS  PubMed  Google Scholar 

  • Mommsen TP, Moon TW, Walsh TJ (1994) Hepatocytes: isolation, maintenance and utilization. In: Hochachka PW, Mommsen TP (eds) Biochemistry and molecular biology of fishes. Elsevier Science B.V, Amsterdam

    Google Scholar 

  • Pfaffl MW (2001) A new mathematical model for relative quantification in real-time RT-PCR. Nucleic Acids Res 29:E45

    Article  CAS  PubMed  Google Scholar 

  • Plagnes-Juan E, Lansard M, Seiliez I, Medale F, Corraze G, Kaushik S, Panserat S, Skiba-Cassy S (2008) Insulin regulates the expression of several metabolism-related genes in the liver and primary hepatocytes of rainbow trout (Oncorhynchus mykiss). J Exp Biol 211:2510–2518

    Article  CAS  PubMed  Google Scholar 

  • Polakof S, Skiba-Cassy S, Panserat S (2009) Glucose homeostasis is impaired by a paradoxical interaction between metformin and insulin in carnivorous rainbow trout. Am J Physiol Regul Integr Comp Physiol 297:R1769–R1776

    Google Scholar 

  • Porstmann T, Santos CR, Griffiths B, Cully M, Wu M, Leevers S, Griffiths JR, Chung YL, Schulze A (2008) SREBP activity is regulated by mTORC1 and contributes to Akt-dependent cell growth. Cell Metab 8:224–236

    Article  CAS  PubMed  Google Scholar 

  • Sancak Y, Peterson TR, Shaul YD, Lindquist RA, Thoreen CC, Bar-Peled L, Sabatini DM (2008) The Rag GTPases bind raptor and mediate amino acid signaling to mTORC1. Science 320:1496–1501

    Article  CAS  PubMed  Google Scholar 

  • Schmoll D (2000) Regulation of glucose-6-phosphatase gene expression by protein kinase B[alpha] and the forkhead transcription factor FKHR. Evidence for insulin response unit-dependent and -independent effects of insulin on promoter activity. J Biol Chem 275:36324–36333

    Article  CAS  PubMed  Google Scholar 

  • Segner H (1998) Isolation and primary culture of teleost hepatocytes. Comp Biochem Physiol A 120:71–81

    Article  Google Scholar 

  • Seiliez I, Gabillard JC, Skiba-Cassy S, Garcia-Serrana D, Gutierrez J, Kaushik S, Panserat S, Tesseraud S (2008) An in vivo and in vitro assessment of TOR signaling cascade in rainbow trout (Oncorhynchus mykiss). Am J Physiol Regul Integr Comp Physiol 295:329–335

    Google Scholar 

  • Skiba-Cassy S, Lansard M, Panserat S, Medale F (2009) Rainbow trout genetically selected for greater muscle fat content display increased activation of liver TOR signaling and lipogenic gene expression 10.1152/ajpregu.00312.2009. Am J Physiol Regul Integr Comp Physiol 297:R1421–R1429

    CAS  PubMed  Google Scholar 

  • Smith S, Witkowski A, Joshi AK (2003) Structural and functional organization of the animal fatty acid synthase. Prog Lipid Res 42:289–317

    Article  CAS  PubMed  Google Scholar 

  • Snell K (1984) Enzymes of serine metabolism in normal, developing and neoplastic rat tissues. Adv Enzyme Regul 22:325–400

    Article  CAS  PubMed  Google Scholar 

  • Taniguchi CM, Emanuelli B, Kahn CR (2006) Critical nodes in signalling pathways: insights into insulin action. Nat Rev Mol Cell Biol 7:85–96

    Article  CAS  PubMed  Google Scholar 

  • Towle HC (2005) Glucose as a regulator of eukaryotic gene transcription. Trends Endocrinol Metab 16:489–494

    Article  CAS  PubMed  Google Scholar 

  • Towle HC, Kaytor EN, Shih H (1997) Regulation of the expression of lipogenic enzyme genes by carbohydrate. Annu Rev Nutr 17:405–433

    Article  CAS  PubMed  Google Scholar 

  • Tremblay F, Marette A (2001) Amino acid and insulin signaling via the mTOR/p70 S6 kinase pathway. A negative feedback mechanism leading to insulin resistance in skeletal muscle cells. J Biol Chem 276:38052–38060

    CAS  PubMed  Google Scholar 

  • Tremblay F, Brule S, Hee Um S, Li Y, Masuda K, Roden M, Sun XJ, Krebs M, Polakiewicz RD, Thomas G, Marette A (2007a) Identification of IRS-1 Ser-1101 as a target of S6K1 in nutrient- and obesity-induced insulin resistance. Proc Natl Acad Sci USA 104:14056–14061

    Article  CAS  PubMed  Google Scholar 

  • Tremblay F, Lavigne C, Jacques H, Marette A (2007b) Role of dietary proteins and amino acids in the pathogenesis of insulin resistance. Annu Rev Nutr 27

  • Wullschleger S, Loewith R, Hall MN (2006) TOR signaling in growth and metabolism. Cell 124:471–484

    Article  CAS  PubMed  Google Scholar 

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Acknowledgments

We thank M. Larquier and L. Gruyère for technical assistance, and F. Terrier, Y. Hontang and F. Sandres for fish rearing in the INRA experimental farm (Donzacq, France). This study was supported by the European Union 6th Framework project (Contract No. 016249-2, Sustainable aquafeeds to maximise the health benefits of farmed fish for consumers—AQUAMAX), French national research agency (ANR-08-JCJC-0025, Low utilisation of dietary carbohydrates in carnivorous rainbow trout: role of amino acids, glucose and insulin interactions?) and the Aquitaine Region (No. CCRRDT-20051303004AB). The AQUAMAX European project (Contract No. 016249-2) also provided M.L. with a fellowship.

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Correspondence to Sandrine Skiba-Cassy.

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Lansard, M., Panserat, S., Plagnes-Juan, E. et al. Integration of insulin and amino acid signals that regulate hepatic metabolism-related gene expression in rainbow trout: role of TOR. Amino Acids 39, 801–810 (2010). https://doi.org/10.1007/s00726-010-0533-3

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  • DOI: https://doi.org/10.1007/s00726-010-0533-3

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