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| 1 | Differential regulation of protein synthesis in skeletal muscle and liver of neonatal pigs by leucine through an mTORC1-dependent pathway显示文摘Neonatal growth is characterized by a high protein synthesis rate that is largely due to an enhanced sensitivity to the postprandial rise in insulin and amino acids, especially leucine. The mechanism of leucine's action in vivo is not well understood. In this study, we investigated the effect of leucine infusion on protein synthesis in skeletal muscle and liver of neonatal pigs. To evaluate the mode of action of leucine, we used rapamycin, an inhibitor of mammalian target of rapamycin (mTOR) complex-1 (mTORC1). Overnight-fasted 7-day-old piglets were treated with rapamycin for 1 hour and then infused with leucine (400 μmol·kg -1 ·h -1 ) for 1 hour. Leucine infusion increased the rate of protein synthesis, and ribosomal protein S6 kinase 1 (S6K1) and eukaryotic initiation factor (eIF) 4E-binding protein-1 (4E-BP1) phosphorylation in gastrocnemius and masseter muscles (P < 0.05), but not in the liver. The leucine-induced stimulation of protein synthesis and S6K1 and 4E-BP1 phosphorylation were completely blocked by rapamycin, suggesting that leucine action is by an mTORC1-dependent mechanism. Neither leucine nor rapamycin had any effect on the activation of the upstream mTORC1 regulators, AMP-activated protein kinase and protein kinase B, in skeletal muscle or liver. The activation of eIF2a and elongation factor 2 was not affected by leucine or rapamycin, indicating that these two pathways are not limiting steps of leucine-induced protein synthesis. These results suggest that leucine stimulates muscle protein synthesis in neonatal pigs by inducing the activation of mTORC1 and its downstream pathway leading to mRNA translation. | Agus Suryawan Hanh V Nguyen Rosemarie D Almonaci Teresa A Davis | 2012 | Journal of Animal Science and Biotechnology2012，3，1： | 9 |
| 2 | Regulation of protein degradation pathways by amino acids and insulin in skeletal muscle of neonatal pigs显示文摘Background:The rapid gain in lean mass in neonates requires greater rates of protein synthesis than degradation.We previously delineated the molecular mechanisms by which insulin and amino acids,especially leucine,modulate skeletal muscle protein synthesis and how this changes with development.In the current study,we identified mechanisms involved in protein degradation regulation.In experiment 1,6- and 26-d-old pigs were studied during 1) euinsulinemic-euglycemic-euaminoacidemic,2) euinsulinemic-euglycemic-hyperaminoacidemic,and 3)hyperinsulinemic-euglycemic-euaminoacidemic clamps for 2 h.In experiment 2,5-d-old pigs were studied during1) euinsulinemic-euglycemic-euaminoacidemic-euleucinemic,2) euinsulinemic-euglycemic-hypoaminoacidemichyperleucinemic,and 3) euinsulinemic-euglycemic-euaminoacidemic-hyperleucinemic clamps for 24 h.We determined in muscle indices of ubiquitin-proteasome,i.e.,atrogin-1(MAFbx) and muscle RING-finger protein-1(MuRFI) and autophagy-lysosome systems,i.e.,unc51-like kinase 1(UKL1),microtubule-associated protein light chain 3(LC3),and lysosomal-associated membrane protein 2(Lamp-2).For comparison,we measured ribosomal protein S6(rpS6) and eukaryotic initiation factor 4E(elF4E) activation,components of translation initiation.Results:Abundance of atrogin-1,but not MuRFI,was greater in 26- than 6-d-old pigs and was not affected by insulin,amino acids,or leucine.Abundance of ULK1 and LC3 was higher in younger pigs and not affected by treatment.The LC3-II/LC3-I ratio was reduced and ULK1 phosphorylation increased by insulin,amino acids,and leucine.These responses were more profound in younger pigs.Abundance of Lamp-2 was not affected by treatment or development.Abundance of elF4 E,but not rpS6,was higher in 6- than 26-d-old-pigs but unaffected by treatment.Phosphorylation of elF4 E was not affected by treatment,however,insulin,amino acids,and leucine stimulated rpS6 phosphorylation,and the responses decreased with development.Conclusions:The rapid growth of neonatal muscle is in part due to the positive balance between the activation of protein synthesis and degradation signaling.Insulin,amino acids,and,particularly,leucine,act as signals to modulate muscle protein synthesis and degradation in neonates. | Agus Suryawan Teresa A Davis | 2014 | Journal of Animal Science and Biotechnology2014，5，3： | 4 |
| 3 | Graduated compression stockings in the prevention of venous thrombo- embolism显示文摘 | AGU O SEIFALIAN A HAMILTON G BAKER D | 1999 | Br J Surg1999，86，： | 1 |
| 4 | A multiprocessor decoupled aystem for the simulation of temporal bone surgery显示文摘 | Agus M Giachetti A Gobbetti E | | 0，，01： | 1 |
| 5 | Idiopathic granulomatous mastitis lesion mimicking inflamma- tory breast cancer显示文摘 | Martin A Nzegwu Kenneth A Agu Peace I Amaraegbulam | 2007 | CMAJ2007，176，13： | 1 |
| 6 | A new unexcited synchronous ma- chine显示文摘 | LAWRENSON P J AGU L A | 1963 | Proceedings of the Institution of Electrical Engineers1963，110，7： | 1 |
| 7 | Successful results of minimally invasive surgeryfor comminuted supracondylar femoral fractures with LISS: comparative study of multiply injured and isolated femoral fractures显示文摘 | Kayali C Agus H Turgut A | 2007 | J Orthop Sci2007，12，4： | 1 |
| 8 | Genetic diversity of isolates of the Leptosphaeria maculans species complex from Australia, Europe and North America using ampli- fied fragment length polymorphism analysis 显示文摘 | Agus P Barrins J M Cozijnsen A J | 2000 | Myco- logical Research2000，104，7： | 1 |
| 9 | Systemic effects of chronic obstructive pulmonary disease 显示文摘 | Agus ti AG Noguera A Sauleda 1 | 2003 | Eur Respir ]2003，21，： | 1 |
| 10 | Image segmentation by histogram thresholding using hierarchical cluster analysis 显示文摘 | Agus Z A Akira A | 2006 | Pattern Recognition Letters2006，27，13： | 1 |
| 11 | Successful results of minimally invasive surgery for comminuted supracondylar femoral fractures with LISS: comparative study of multiply injured and isolated femoral fractures 显示文摘 | Kayali C Agus H Turgut A | 2007 | J Orthop Sei2007，12，5： | 1 |
| 12 | Measurement of center - edge angle in developmental dysplasia of the hip: a comparison of two methods in patients under 20 years of age 显示文摘 | Omeroglu H Biqimoglu A Agu H | 2002 | Skeletal Radiol2002，1，： | 1 |
| 13 | Surgical treatment of symptomatic discoid medial meniscus in childhood: a case report显示文摘 | Kalenderer O Turkenb M A Agus H | 2012 | J Pediatr Orthop B2012，21，4： | 1 |
| 14 | Successful results of minimally invasive surgery for comminuted supracondylar femoral actures with LISS: comparative study of multiply injured and isolated femoral fractures显示文摘 | Kayali C Agus H Turgut A | 2007 | J Orthop Sci2007，12，5： | 1 |
| 15 | Moisture diffusivity coefficient and convective drying, mdelling of nmrta ( Ugni molinae Turcz) : influence of temperature and vacuum on drying kinetics 显示文摘 | Kong A H Zambra C E Agu~ro J E Antonio V G Roberto Lemus- Mondaca | 2012 | Food and Bioprocess Technology2012，6，4： | 1 |
| 16 | Successful results of minimal- ly invasive surgery for comminuted supracondylar femoral fractures with LISS: Comparative study of multiply injured and isolated femoral fractures 显示文摘 | Kayali C Agus H Turgut A | 2007 | J Orthop Sci2007，12，5： | 1 |
| 17 | A Randomized, Placebo-Controlled, Double-Blind Trial of the Effect of Combined Therapy With Deferoxamine and Deferiprone on Myocardial Iron in Thalassemia Major Using Cardiovascular Magnetic Resonance显示文摘 | M A. Tanner R Galanello C Dessi G C. Smith M A. Westwood A Agus M Roughton R Assomull S V. Nair J M. Walker D J. Pennell | 2007 | Circulation2007，，： | 1 |
| 18 | Effect of graduated compression stockings on limb oxygenation and venous function during exercise in patients with venous insufficiency 显示文摘 | ] AGU O BAKER D SEIFALIAN A M | 2004 | Vascular2004，12，1： | 1 |
| 19 | Measurement of center-edge angle in developmental dysplasia of the hip: a comparison of two methods in patients under 20 years of age显示文摘 | Omeroglu H bicimoglu A Agus H | 2002 | Skeletal Radiol2002，31，1： | 1 |
| 20 | Image segmentation by histogram thresholding using hierarchical cluster analysis 显示文摘 | Agus Z A Akira A | 2006 | Pattern Recognition Letter2006，27，13： | 1 |
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