Dietary carbohydrate-to-protein ratio affects TOR signaling and metabolism-related gene expression in the liver and muscle of rainbow trout after a single meal
Open Access
- 1 March 2011
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
- Vol. 300 (3), R733-R743
- https://doi.org/10.1152/ajpregu.00579.2010
Abstract
Most teleost fish are known to require high levels of dietary proteins. Such high-protein intake could have significant effects, particularly on insulin-regulated gene expression. We therefore analyzed the effects of an increase in the ratio of dietary carbohydrates/proteins on the refeeding activation of the Akt-target of rapamycin (TOR) signaling pathways in rainbow trout and the effects on the expression of several genes related to hepatic and muscle metabolism and known to be regulated by insulin, amino acids, and/or glucose. Fish were fed once one of three experimental diets containing high (H), medium (M), or low (L) protein (P) or carbohydrate (C) levels after 48 h of feed deprivation. Activation of the Akt/TOR signaling pathway by refeeding was severely impaired by decreasing the proteins-to-carbohydrates ratio. Similarly, postprandial regulation of several genes related to glucose (Glut4, glucose-6-phosphatase isoform 1), lipid (fatty acid synthase, ATP-citrate lyase, sterol responsive element binding protein, carnitine palmitoyltransferase 1, and 3-hydroxyacyl-CoA dehydrogenase), and amino acid metabolism (serine dehydratase and branched-chain α-keto acid dehydrogenase E2 subunit) only occurred when fish were fed the high-protein diet. On the other hand, diet composition had a low impact on the expression of genes related to muscle protein degradation. Interestingly, glucokinase was the only gene of those monitored whose expression was significantly upregulated by increased carbohydrate intake. In conclusion, this study demonstrated that macro-nutrient composition of the diet strongly affected the insulin/amino acids signaling pathway and expression pattern of genes related to metabolism.Keywords
This publication has 53 references indexed in Scilit:
- Integration of insulin and amino acid signals that regulate hepatic metabolism-related gene expression in rainbow trout: role of TORAmino Acids, 2010
- Rainbow trout genetically selected for greater muscle fat content display increased activation of liver TOR signaling and lipogenic gene expressionAmerican Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2009
- Effect of starvation on transcriptomes of brain and liver in adult female zebrafish (Danio rerio)Physiological Genomics, 2008
- SREBP Activity Is Regulated by mTORC1 and Contributes to Akt-Dependent Cell GrowthCell Metabolism, 2008
- Role of Akt/GSK-3β/β-Catenin Transduction Pathway in the Muscle Anti-Atrophy Action of Insulin-Like Growth Factor-I in Glucocorticoid-Treated RatsEndocrinology, 2008
- An Update on MyoD Evolution in Teleosts and a Proposed Consensus Nomenclature to Accommodate the Tetraploidization of Different Vertebrate GenomesPLOS ONE, 2008
- Effect of starvation on global gene expression and proteolysis in rainbow trout (Oncorhynchus mykiss)BMC Genomics, 2007
- Critical nodes in signalling pathways: insights into insulin actionNature Reviews Molecular Cell Biology, 2006
- Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotypeNature, 2004
- Utilization of dietary carbohydrate by fishAquaculture, 1994