Venezia by PVII

Dr. Teresa DavisTeresa A. Davis, Ph.D.

Professor
Baylor College of Medicine
tdavis@bcm.tmc.edu

Adjunct Professor
Department of Animal Science and Intercollegiate Faculty of Nutrition
Texas A&M University

Regulation of Protein Metabolism by Nutrients and Hormones During Early Life

The long-term objective of my research is to identify the mechanisms by which nutrients, hormones, and growth factors regulate protein deposition, particularly in skeletal muscle, during growth and development.

Early studies demonstrated that the high rate of protein deposition in the neonate is due to the elevated response of protein synthesis to nutrient intake, which is particularly profound in skeletal muscle. Using novel hormone-substrate clamps, the feeding-induced stimulation of protein synthesis was shown to involve independent regulation by both insulin and amino acids in skeletal muscle, and to be mediated by either amino acids or insulin alone in other tissues. Recent studies are demonstrating that the high rate of muscle protein synthesis in the neonate is regulated by the expression and activity of components of the intracellular insulin and nutrient signaling pathways that control translation initiation. The role of branched-chain amino acids and glucose in the regulation of protein synthesis in the neonate is also being explored. Other research areas being investigated include the regulation of protein synthesis during catabolic illness such as sepsis and the role of nutrient intake in the anabolic response to growth hormone.

The importance of this research lies in the fact that mechanisms that regulate protein deposition in neonates must be identified before effective strategies to optimize nutrient utilization for growth can be developed. Such strategies, in turn, are important to improve outcome of growth-retarded infants and to improve animal production.

Dr. Davis' lab

Dr Davis' Lab Group

Representative Publications:

Orellana RA, Kimball SR, Suryawan A, Escobar J, Nguyen HV, Jefferson LS, and Davis TA. Insulin stimulates muscle protein synthesis in neonates during endotoxemia despite suppression of translation initiation. Am J Physiol Endocrinol Metab 292: E629-636, 2007.

Jeyapalan AS, Orellana RA, Suryawan A, Nguyen HV, Escobar J, Frank J, and Davis TA. Stimulation of muscle protein synthesis by glucose in neonates is AMP kinase and mTOR independent. Am J Physiol Endocrinol Metab 293: E595-E603, 2007.

Frank J, Escobar J, Nguyen HV, Jobgen SC, Jobgen WS, Davis TA, and Wu G. Oral N-carbamylglutamate supplementation increases protein synthesis in skeletal muscle of pigets. J Nutr 137: 315-319, 2007.

Gingras A, White PJ, Chouinard PY, Julien P, Davis TA, Dombrowski L, Couture Y, Dubreuil P, Myre A, Bergeron K, Marette A, and Thivierge MC. Long-chain omega-3 fatty acids regulate bovine whole-body protein metabolism by promoting muscle insulin signaling to the Akt-mTOR-S6K1 pathway and insulin sensitivity. J Physiol 579: 269-284, 2007.

Suryawan A, Escobar J, Frank JW, Nguyen HV, and Davis TA. Developmental regulation of the activation of signaling components leading to translation initiation in skeletal muscle of neonatal pigs. Am J Physiol Endocrinol Metab 291: E849-E859, 2006.

Frank JW, Escobar J, Suryawan A, Nguyen HV, Kimball SR, Jefferson LS, and Davis TA. Increasing dietary protein from low to adequate levels increases translation initiation factor activation and tissue protein synthesis. Am Physiol Endocrinol Metab 290: E225-E233, 2006.

Suryawan A, Frank JW, Nguyen HV, and Davis TA. Expression of the TGF-? family of ligands is developmentally regulated in skeletal muscle of neonatal rats. Pediatr Res 59: 175-9, 2006.

Escobar J, Frank JW, Suryawan A, Nguyen HV, and Davis TA. Regulation of cardiac and skeletal muscle protein synthesis by branched-chain amino acids in neonates. Am J Physiol Endocrinol Metab 290: E612-E21, 2006.

Orellana RA, O’Connor PMJ, Bush JA, Suryawan A, Thivierge MC, Nguyen HV, Fiorotto ML, and Davis TA. Modulation of muscle protein synthesis by insulin is maintained during neonatal endotoxemia. Am J Physiol Endocrinol Metab 291: E159-E166, 2006.

Thieverge MC, Bush JA, Suryawan A, Nguyen HV, Orellana R, Burrin DG, Jahoor F, and Davis TA. Whole body and hindlimb protein breakdown in differentially altered by feeding in neonatal piglets. J Nutr 135: 1430-1437, 2005.

Frank JW, Escobar J, Suryawan A, Kimball SR, Nguyen HV, Jefferson LS, and Davis TA. Protein synthesis and translation initiation factor activation in neonatal pigs fed increasing levels of dietary protein. J Nutr 135: 1374-1381, 2005.

Escobar J, Frank JW, Suryawan A, Nguyen HV, Kimball SR, Jefferson LS, and Davis TA. A physiological rise in plasma leucine stimulates muscle protein synthesis in neonatal pigs by enhancing translation initiation factor activation. Am J Physiol Endocrinol Metab 288: E914-E921, 2005.

Suryawan A and Davis TA. Developmental regulation of protein kinase B activation is isoform specific in skeletal muscle of neonatal pigs. Pediatric Res 58: 1-5, 2005.

Burrin DG and Davis TA. Proteins and amino acids in enteral nutrition. Curr Opinion Clin Nutr Metab Care 7: 79-87, 2004.

Suryawan A, O’Connor PMJ, Kimball SR, Bush JA, Nguyen HV, Jefferson LS, and Davis TA. Amino acids do not alter the insulin-induced activation of the insulin signaling pathway in neonatal pigs. J Nutr 134: 24-30, 2004.

Orellana RA, Kimball SR, Nguyen HV, Bush JA, Suryawan A, Thivierge MC, Jefferson LS, and Davis TA. Regulation of muscle protein synthesis in neonatal pigs during prolonged endotoxemia. Pediatr Res 55: 442-449, 2004.

O’Connor PMJ, Kimball SR, Suryawan A, Bush JA, Nguyen HV, Jefferson LS, and Davis TA. Regulation of neonatal liver protein synthesis by insulin and amino acids in neonatal pigs. Am J Physiol Endocrinol Metab 286: E994-E1003, 2004.

Davis TA, Bush JA, Vann RC, Suryawan A, Kimball SR, and Burrin DG. Somatotropin regulation of protein metabolism in pigs. J Anim Sci 82: E207-E213, 2004.

Suryawan A and Davis TA. Protein tyrosine phosphatase 1B activation is developmentally regulated in muscle of neonatal pigs. Am J Physiol Endocrinol Metab 284: E47-E54, 2003.

O’Connor PMJ, Kimball SR, Suryawan A, Bush JA, Nguyen HV, and Davis TA. Insulin and amino acids independently stimulate skeletal muscle protein synthesis in neonatal pigs. Am J Physiol Endocrinol Metab 284: E110-E119, 2003.

Bush JA, Burrin DG, Reeds PJ, Suryawan A, O’Connor PMJ, Nguyen HV, van Goudoever J, and Davis TA. Somatotropin-induced protein anabolism in the hindquarter and portal drained viscera of growing pigs. Am J Physiol Endocrinol Metab 284: E302-E312, 2003.

Bush JA, Kimball SR, Suryawan A, O’Connor PMJ, Orellana R, Nguyen HV, Jefferson LS, and Davis TA. Translational control of protein synthesis in muscle and liver of growth hormone-treated pigs. Endocrinology 144: 1273-1283, 2003.

O’Connor PMJ, Kimball SR, Suryawan A, Bush JA, Nguyen HV, Jefferson LS, Davis TA. Regulation of translation initiation by insulin and amino acids in skeletal muscle of neonatal pigs. Am J Physiol Endocrinol Metab 285: E40-53, 2003.

Kimball SR, Orellana RA, O’Connor, Suryawan A. Bush JA, Nguyen HV, Thivierge MC, Jefferson LS, and Davis TA. Differential regulation of protein synthesis in skeletal muscle and liver of neonatal pigs in experimentally-induced sepsis. Am J Physiol Endocrinol Metab 285: E637-E644, 2003.

Suryawan A, Nguyen HV, Orellana RA, Bush JA, and Davis TA. Insulin/insulin-like growth factor-I hybrid receptor abundance decreases with development in neonatal pigs. J Nutr 133: 2783-2787, 2003.

Davis TA, Suryawan A, Bush JA, O’Connor MJ, and Thivierge MC. Interaction of amino acids and insulin in the regulation of protein metabolism in growing animals. Can J Anim Sci 83: 357-364, 2003.

Bush JA, Wu G, Suryawan A, Nguyen HV, and Davis TA. Somatotropin-induced amino acid conservation involves differential regulation of liver and gut urea cycle enzyme activity. J Nutr 132: 59-67, 2002.

Kimball SR, Farrell PA, Nguyen HV, Jefferson LS, and Davis TA. Developmental decline in components of signal transduction pathways regulating muscle protein synthesis in neonatal pigs. Am J Physiol Endocrinol Metab 282: E585-E592, 2002.

Davis TA, Fiorotto ML, Burrin DG, Reeds PJ, Nguyen HV, Beckett PR, Vann RC, and O’Connor PMJ. Simulation of protein synthesis by both insulin and amino acids is unique to skeletal muscle in neonatal pigs. Am J Physiol Endocrinol Metab 282: E880-E890, 2002.

Davis TA, Fiorotto ML, Burrin DG, Vann RC, Reeds PJ, Nguyen HV, Beckett PR, and Bush JA. Acute IGF-I infusion stimulates protein synthesis in skeletal muscle and other tissues of neonatal pigs. Am J Physiol Endocrinol Metab 283: E638-E647, 2002.

Orellana, RA, O’Connor PMJ, Nguyen HV, Bush JA, Thivierge C, Suryawan A, Fiorotto ML, and Davis TA. Endotoxemia reduces muscle protein synthesis in neonates. Am J Physiol Endocrinol Metab 283: E909-E916, 2002.

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