Differential Regulation of Protein Synthesis and mTOR Signaling in Skeletal Muscle and Visceral Tissues of Neonatal Pigs After a Meal
| Autor: | Renán A. Orellana, Teresa A. Davis, Fiona A. Wilson, Maria C. Gazzaneo, Roberto Murgas Torrazza, Hanh V. Nguyen, Alexander P. Tuckow, Agus Suryawan, Scot R. Kimball, Marta L. Fiorotto |
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| Rok vydání: | 2011 |
| Předmět: |
Ribosomal Proteins
medicine.medical_specialty Swine mTORC1 Biology Article Eating Random Allocation Internal medicine medicine Animals Muscle Skeletal Protein kinase A Protein kinase B PI3K/AKT/mTOR pathway Kinase TOR Serine-Threonine Kinases Eukaryotic initiation factor 4E binding Skeletal muscle Enzyme Activation Viscera Endocrinology medicine.anatomical_structure Animals Newborn Polyribosomes Protein Biosynthesis Pediatrics Perinatology and Child Health Phosphorylation Signal Transduction |
| Zdroj: | Pediatric Research. 70:253-260 |
| ISSN: | 1530-0447 0031-3998 |
| DOI: | 10.1203/pdr.0b013e3182276cfa |
| Popis: | Protein synthesis (PS) increases after a meal in neonates, but the time course of the changes in PS in different tissues after a meal is unknown. We aimed to evaluate the changes in tissue PS, mammalian target of rapamycin complex 1 (mTORC1) activation, and proportion of ribosomal protein (rp) mRNAs in polysomes over 4 h following a bolus meal in neonatal pigs (n = 6/group; 5- to 7-d-old). The results show a more sustained increase in PS in glycolytic compared to mixed fiber type muscles, and no changes in oxidative muscles. PS increased in liver, jejunum, and pancreas, but not in kidney and heart. Feeding did not affect AMP-activated protein kinase or RAS-related GTP binding B activation. Phosphorylation of tuberous sclerosis complex 2, proline-rich Akt substrate of 40 kDa, mTOR, eukaryotic initiation factor 4E binding protein, and rp S6 kinase 1 increased in all tissues after feeding. The proportion of mRNAs encoding rp S4 and S8 in liver polysomes increased within 30 min post-feeding. These results suggest that feeding stimulates mTORC1 signaling in muscle and viscera, but mTORC1 activation alone is not sufficient to stimulate PS in all tissues. |
| Databáze: | OpenAIRE |
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