1
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Affourtit C, Carré JE. Mitochondrial involvement in sarcopenia. Acta Physiol (Oxf) 2024; 240:e14107. [PMID: 38304924 DOI: 10.1111/apha.14107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 02/03/2024]
Abstract
Sarcopenia lowers the quality-of-life for millions of people across the world, as accelerated loss of skeletal muscle mass and function contributes to both age- and disease-related frailty. Physical activity remains the only proven therapy for sarcopenia to date, but alternatives are much sought after to manage this progressive muscle disorder in individuals who are unable to exercise. Mitochondria have been widely implicated in the etiology of sarcopenia and are increasingly suggested as attractive therapeutic targets to help restore the perturbed balance between protein synthesis and breakdown that underpins skeletal muscle atrophy. Reviewing current literature, we note that mitochondrial bioenergetic changes in sarcopenia are generally interpreted as intrinsic dysfunction that renders muscle cells incapable of making sufficient ATP to fuel protein synthesis. Based on the reported mitochondrial effects of therapeutic interventions, however, we argue that the observed bioenergetic changes may instead reflect an adaptation to pathologically decreased energy expenditure in sarcopenic muscle. Discrimination between these mechanistic possibilities will be crucial for improving the management of sarcopenia.
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Affiliation(s)
| | - Jane E Carré
- School of Biomedical Sciences, University of Plymouth, Plymouth, UK
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2
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Saadi S, Makhlouf C, Nacer NE, Halima B, Faiza A, Kahina H, Wahiba F, Afaf K, Rabah K, Saoudi Z. Whey proteins as multifunctional food materials: Recent advancements in hydrolysis, separation, and peptidomimetic approaches. Compr Rev Food Sci Food Saf 2024; 23:e13288. [PMID: 38284584 DOI: 10.1111/1541-4337.13288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/23/2023] [Accepted: 12/11/2023] [Indexed: 01/30/2024]
Abstract
Whey protein derived bioactives, including α-lactalbumin, ß-lactoglobulin, bovine serum albumin, lactoferrin, transferrin, and proteose-peptones, have exhibited wide ranges of functional, biological and therapeutic properties varying from anticancer, antihypertensive, and antimicrobial effects. In addition, their functional properties involve gelling, emulsifying, and foaming abilities. For these reasons, this review article is framed to understand the relationship existed in between those compound levels and structures with their main functional, biological, and therapeutic properties exhibited either in vitro or in vivo. The impacts of hydrolysis mechanism and separation techniques in enhancing those properties are likewise discussed. Furthermore, special emphasize is given to multifunctional effects of whey derived bioactives and their future trends in ameliorating further food, pharmaceutical, and nutraceutical products. The underlying mechanism effects of those properties are still remained unclear in terms of activity levels, efficacy, and targeted effectiveness. For these reasons, some important models linking to functional properties, thermal properties and cell circumstances are established. Moreover, the coexistence of radical trapping groups, chelating groups, sulfhydryl groups, inhibitory groups, and peptide bonds seemed to be the key elements in triggering those functions and properties. Practical Application: Whey proteins are the byproducts of cheese processing and usually the exploitation of these food waste products has increasingly getting acceptance in many countries, especially European countries. Whey proteins share comparable nutritive values to milk products, particularly on their richness on important proteins that can serve immune protection, structural, and energetic roles. The nutritive profile of whey proteins shows diverse type of bioactive molecules like α-lactalbumin, ß-lactoglobulin, lactoferrin, transferrin, immunoglobulin, and proteose peptones with wide biological importance to the living system, such as in maintaining immunological, neuronal, and signaling roles. The diversification of proteins of whey products prompted scientists to exploit the real mechanisms behind of their biological and therapeutic effects, especially in declining the risk of cancer, tumor, and further complications like diabetes type 2 and hypertension risk effects. For these reasons, profiling these types of proteins using different proteomic and peptidomic approaches helps in determining their biological and therapeutic targets along with their release into gastrointestinal tract conditions and their bioavailabilities into portal circulation, tissue, and organs. The wide applicability of those protein fractions and their derivative bioactive products showed significant impacts in the field of emulsion and double emulsion stabilization by playing roles as emulsifying, surfactant, stabilizing, and foaming agents. Their amphoteric properties helped them to act as excellent encapsulating agents, particularly as vehicle for delivering important vitamins and bioactive compounds. The presence of ferric elements increased their transportation to several metal-ions in the same time increased their scavenging effects to metal-transition and peroxidation of lipids. Their richness with almost essential and nonessential amino acids makes them as selective microbial starters, in addition their richness in sulfhydryl amino acids allowed them to act a cross-linker in conjugating further biomolecules. For instance, conjugating gold-nanoparticles and fluorescent materials in targeting diseases like cancer and tumors in vivo is considered the cutting-edges strategies for these versatile molecules due to their active diffusion across-cell membrane and the presence of specific transporters to these therapeutic molecules.
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Affiliation(s)
- Sami Saadi
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratoire de Génie Agro-alimentaire, équipe Génie des Procédés Alimentaires, Biodiversité et Agro environnement, INATAA, Université Frères Mentouri Constantine 1 (UFC1), Constantine, Algeria
| | - Chaalal Makhlouf
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratory of Biotechnology and Food Quality, Institute of Nutrition, Food and Agro-Food Technologies, University of Constantine 1, Constantine, Algeria
- Laboratory of Applied Biochemistry, Faculty of Nature and Life Science, University of Bejaia, Bejaia, Algeria
| | - Nor Elhouda Nacer
- Department of Biology of Organisms, Faculty of Natural and Life Sciences, University of Batna 2, Batna, Algeria
| | - Boughellout Halima
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratoire de Génie Agro-alimentaire, équipe Génie des Procédés Alimentaires, Biodiversité et Agro environnement, INATAA, Université Frères Mentouri Constantine 1 (UFC1), Constantine, Algeria
| | - Adoui Faiza
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratoire de Génie Agro-alimentaire, équipe Génie des Procédés Alimentaires, Biodiversité et Agro environnement, INATAA, Université Frères Mentouri Constantine 1 (UFC1), Constantine, Algeria
| | - Hafid Kahina
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Equipe MaQuaV, Laboratoire Bioqual INATAA, Université des Frères Mentouri-Constantine 1, Constantine, Algeria
| | - Falek Wahiba
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratoire de Génie Agro-alimentaire, équipe Génie des Procédés Alimentaires, Biodiversité et Agro environnement, INATAA, Université Frères Mentouri Constantine 1 (UFC1), Constantine, Algeria
| | - Kheroufi Afaf
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratoire de Génie Agro-alimentaire, équipe Génie des Procédés Alimentaires, Biodiversité et Agro environnement, INATAA, Université Frères Mentouri Constantine 1 (UFC1), Constantine, Algeria
| | - Kezih Rabah
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratory of Biotechnology and Food Quality, Institute of Nutrition, Food and Agro-Food Technologies, University of Constantine 1, Constantine, Algeria
| | - Zineddine Saoudi
- Institut de la Nutrition, de l'Alimentation et des Technologies Agroalimentaires (INATAA), Université Frères Mentouri Constantine 1, Constantine, Algeria
- Laboratoire de Génie Agro-alimentaire, équipe Génie des Procédés Alimentaires, Biodiversité et Agro environnement, INATAA, Université Frères Mentouri Constantine 1 (UFC1), Constantine, Algeria
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3
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Rosario FJ, Urschitz J, Powell TL, Brown TL, Jansson T. Overexpression of the LAT1 in primary human trophoblast cells increases the uptake of essential amino acids and activates mTOR signaling. Clin Sci (Lond) 2023; 137:1651-1664. [PMID: 37861075 DOI: 10.1042/cs20230490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 10/21/2023]
Abstract
The System L amino acid transporter, particularly the isoform Large Neutral Amino Acid Transporter Small Subunit 1 (LAT1) encoded by SLC7A5, is believed to mediate the transfer of essential amino acids in the human placenta. Placental System L amino acid transporter expression and activity is decreased in pregnancies complicated by IUGR and increased in fetal overgrowth. However, it remains unknown if changes in the expression of LAT1 are mechanistically linked to System L amino acid transport activity. Here, we combined overexpression approaches with protein analysis and functional studies in cultured primary human trophoblast (PHT) cells to test the hypothesis that SLC7A5 overexpression increases the uptake of essential amino acids and activates mTOR signaling in PHT cells. Overexpression of SLC7A5 resulted in a marked increase in protein expression of LAT1 in the PHT cells microvillous plasma membrane and System L amino acid transporter activity. Moreover, mTOR signaling was activated, and System A amino acid transporter activity increased following SLC7A5 overexpression, suggesting coordination of trophoblast amino transporter expression and activity to ensure balanced nutrient flux to the fetus. This is the first report showing that overexpression of LAT1 is sufficient to increase the uptake of essential amino acids in PHT cells, which activates mTOR, a master regulator of placental function. The decreased placental System L activity in human IUGR and the increased placental activity of this transporter system in some cases of fetal overgrowth may directly contribute to changes in fetal amino acid availability and altered fetal growth in these pregnancy complications.
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Affiliation(s)
- Fredrick J Rosario
- Department of Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, U.S.A
| | - Johann Urschitz
- Institute for Biogenesis Research, University of Hawaii, Honolulu, HI, U.S.A
| | - Theresa L Powell
- Department of Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, U.S.A
- Institute for Biogenesis Research, University of Hawaii, Honolulu, HI, U.S.A
| | - Thomas L Brown
- Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, U.S.A
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University Boonshoft School of Medicine, Dayton, OH, U.S.A
| | - Thomas Jansson
- Department of Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, U.S.A
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Hinkle JS, Rivera CN, Vaughan RA. Branched-Chain Amino Acids and Mitochondrial Biogenesis: An Overview and Mechanistic Summary. Mol Nutr Food Res 2022; 66:e2200109. [PMID: 36047448 PMCID: PMC9786258 DOI: 10.1002/mnfr.202200109] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/17/2022] [Indexed: 12/30/2022]
Abstract
Branched-chain amino acids (BCAA) are essential in the diet and promote several vital cell responses which may have benefits for health and athletic performance, as well as disease prevention. While BCAA are well-known for their ability to stimulate muscle protein synthesis, their effects on cell energetics are also becoming well-documented, but these receive less attention. In this review, much of the current evidence demonstrating BCAA ability (as individual amino acids or as part of dietary mixtures) to alter regulators of cellular energetics with an emphasis on mitochondrial biogenesis and related signaling is highlighted. Several studies have shown, both in vitro and in vivo, that BCAA (either individual or as a mixture) may promote signaling associated with increased mitochondrial biogenesis including the upregulation of master regulator of mitochondrial biogenesis peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), as well as numerous downstream targets and related function. However, sparse data in humans and the difficulty of controlling variables associated with feeding studies leave the physiological relevance of these findings unclear. Future well-controlled diet studies will be needed to assess if BCAA consumption is associated with increased mitochondrial biogenesis and improved metabolic outcomes in healthy and/or diseased human populations.
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Affiliation(s)
- Jason S. Hinkle
- Department of Exercise ScienceHigh Point UniversityHigh PointNC27262‐3598USA
| | - Caroline N. Rivera
- Department of Exercise ScienceHigh Point UniversityHigh PointNC27262‐3598USA
| | - Roger A. Vaughan
- Department of Exercise ScienceHigh Point UniversityHigh PointNC27262‐3598USA
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5
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Park JW, Kim KH, Kim S, So JR, Cho BW, Song KD. Comparative metabolomic analysis in horses and functional analysis of
branched chain (alpha) keto acid dehydrogenase complex in equine myoblasts under
exercise stress. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2022; 64:800-811. [PMID: 35969708 PMCID: PMC9353351 DOI: 10.5187/jast.2022.e45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/28/2022] [Accepted: 06/01/2022] [Indexed: 11/25/2022]
Abstract
The integration of metabolomics and transcriptomics may elucidate the correlation
between the genotypic and phenotypic patterns in organisms. In equine
physiology, various metabolite levels vary during exercise, which may be
correlated with a modified gene expression pattern of related genes. Integrated
metabolomic and transcriptomic studies in horses have not been conducted to
date. The objective of this study was to detect the effect of moderate exercise
on the metabolomic and transcriptomic levels in horses. In this study, using
nuclear magnetic resonance (NMR) spectroscopy, we analyzed the concentrations of
metabolites in muscle and plasma; we also determined the gene expression
patterns of branched chain (alpha) keto acid dehydrogenase kinase complex
(BCKDK), which encodes the key regulatory enzymes in
branched-chain amino acid (BCAA) catabolism, in two breeds of horses,
Thoroughbred and Jeju, at different time intervals. The concentrations of
metabolites in muscle and plasma were measured by 1H NMR (nuclear
magnetic resonance) spectroscopy, and the relative metabolite levels before and
after exercise in the two samples were compared. Subsequently, multivariate data
analysis based on the metabolic profiles was performed using orthogonal partial
least square discriminant analysis (OPLS-DA), and variable important plots and
t-test were used for basic statistical analysis. The
stress-induced expression patterns of BCKDK genes in horse
muscle-derived cells were examined using quantitative reverse transcription
polymerase chain reaction (qPCR) to gain insight into the role of transcript in
response to exercise stress. In this study, we found higher concentrations of
aspartate, leucine, isoleucine, and lysine in the skeletal muscle of Jeju horses
than in Thoroughbred horses. In plasma, compared with Jeju horses, Thoroughbred
horses had higher levels of alanine and methionine before exercise; whereas
post-exercise, lysine levels were increased. Gene expression analysis revealed a
decreased expression level of BCKDK in the post-exercise period
in Thoroughbred horses.
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Affiliation(s)
- Jeong-Woong Park
- Department of Animal Science and
Biotechnology, Kyungpook National University, SangJu 37224,
Korea
| | - Kyoung Hwan Kim
- Department of Animal Science, College of
Natural Resources and Life Sciences, Pusan National
University, Miryang 50463, Korea
| | - Sujung Kim
- The Animal Molecular Genetics and Breeding
Center, Jeonbuk National University, Jeonju 54896, Korea
| | - Jae-rung So
- Department of Animal Science, Jeonbuk
National University, Jeonju 54896, Korea
| | - Byung-Wook Cho
- Department of Animal Science, College of
Natural Resources and Life Sciences, Pusan National
University, Miryang 50463, Korea
- Corresponding author: Byung-Wook Cho,
Department of Animal Science, College of Natural Resources and Life Sciences,
Pusan National University, Miryang 50463, Korea. Tel: +82-55-350-5515, E-mail:
| | - Ki-Duk Song
- The Animal Molecular Genetics and Breeding
Center, Jeonbuk National University, Jeonju 54896, Korea
- Department of Agricultural Convergence
Technology, Jeonbuk National University, Jeonju 54896,
Korea
- Corresponding author: Ki-Duk Song,
Department of Agricultural Convergence Technology, Jeonbuk National University,
Jeonju 54896, Korea. Tel: +82-63-219-5523, E-mail:
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6
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White JP. Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand. Front Cell Dev Biol 2021; 9:656604. [PMID: 34136478 PMCID: PMC8201612 DOI: 10.3389/fcell.2021.656604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/28/2021] [Indexed: 11/20/2022] Open
Abstract
Skeletal muscle protein synthesis is a highly complex process, influenced by nutritional status, mechanical stimuli, repair programs, hormones, and growth factors. The molecular aspects of protein synthesis are centered around the mTORC1 complex. However, the intricacies of mTORC1 regulation, both up and downstream, have expanded overtime. Moreover, the plastic nature of skeletal muscle makes it a unique tissue, having to coordinate between temporal changes in myofiber metabolism and hypertrophy/atrophy stimuli within a tissue with considerable protein content. Skeletal muscle manages the push and pull between anabolic and catabolic pathways through key regulatory proteins to promote energy production in times of nutrient deprivation or activate anabolic pathways in times of nutrient availability and anabolic stimuli. Branched-chain amino acids (BCAAs) can be used for both energy production and signaling to induce protein synthesis. The metabolism of BCAAs occur in tandem with energetic and anabolic processes, converging at several points along their respective pathways. The fate of intramuscular BCAAs adds another layer of regulation, which has consequences to promote or inhibit muscle fiber protein anabolism. This review will outline the general mechanisms of muscle protein synthesis and describe how metabolic pathways can regulate this process. Lastly, we will discuss how BCAA availability and demand coordinate with synthesis mechanisms and identify key factors involved in intramuscular BCAA trafficking.
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Affiliation(s)
- James P White
- Department of Medicine, Duke University School of Medicine, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, United States.,Duke Center for the Study of Aging and Human Development, Duke University School of Medicine, Durham, NC, United States
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7
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Finding new edges: systems approaches to MTOR signaling. Biochem Soc Trans 2021; 49:41-54. [PMID: 33544134 PMCID: PMC7924996 DOI: 10.1042/bst20190730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 11/17/2022]
Abstract
Cells have evolved highly intertwined kinase networks to finely tune cellular homeostasis to the environment. The network converging on the mechanistic target of rapamycin (MTOR) kinase constitutes a central hub that integrates metabolic signals and adapts cellular metabolism and functions to nutritional changes and stress. Feedforward and feedback loops, crosstalks and a plethora of modulators finely balance MTOR-driven anabolic and catabolic processes. This complexity renders it difficult — if not impossible — to intuitively decipher signaling dynamics and network topology. Over the last two decades, systems approaches have emerged as powerful tools to simulate signaling network dynamics and responses. In this review, we discuss the contribution of systems studies to the discovery of novel edges and modulators in the MTOR network in healthy cells and in disease.
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8
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Beef extract supplementation promotes myoblast proliferation and myotube growth in C2C12 cells. Eur J Nutr 2020; 59:3735-3743. [PMID: 32100115 DOI: 10.1007/s00394-020-02205-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 02/12/2020] [Indexed: 02/05/2023]
Abstract
PURPOSE We previously determined that the intake of beef extract for 4 weeks increases skeletal muscle mass in rats. Thus, this study aimed to clarify whether beef extract has a hypertrophic effect on muscle cells and to determine the signaling pathway underlying beef extract-induced myotube hypertrophy. METHODS We assessed the effects of beef extract supplement on mouse C2C12 skeletal muscle cell proliferation and differentiation and myotube growth. In addition, the phosphorylation of Akt, ERK1/2, and mTOR following beef extract supplementation was examined by western blotting. Furthermore, the bioactive constituents of beef extract were examined using amino acid analysis and dialysis. RESULTS In the proliferative stage, beef extract significantly increased myoblast proliferation. In the differentiation stage, beef extract supplementation did not promote myoblast differentiation. In mature myotubes, beef extract supplementation increased myotube diameter and promoted protein synthesis. Although Akt and ERK1/2 levels were not affected, beef extract supplementation increased mTOR phosphorylation, which indicated that the mTOR pathway mediates beef extract-induced myotube hypertrophy. The hypertrophic activity was observed in fractions of > 7000 Da. CONCLUSIONS Beef extract promoted C2C12 myoblast proliferation and C2C12 myotube hypertrophy. Myotube hypertrophy was potentially induced by mTOR activation and active components in beef extract were estimated to be > 7000 Da.
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9
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Suryawan A, Rudar M, Fiorotto ML, Davis TA. Differential regulation of mTORC1 activation by leucine and β-hydroxy-β-methylbutyrate in skeletal muscle of neonatal pigs. J Appl Physiol (1985) 2020; 128:286-295. [PMID: 31944890 DOI: 10.1152/japplphysiol.00332.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leucine (Leu) and its metabolite β-hydroxy-β-methylbutyrate (HMB) stimulate mechanistic target of rapamycin (mTOR) complex 1 (mTORC1)-dependent protein synthesis in the skeletal muscle of neonatal pigs. This study aimed to determine whether HMB and Leu utilize common nutrient-sensing mechanisms to activate mTORC1. In study 1, neonatal pigs were fed one of five diets for 24 h: low protein (LP), high protein (HP), or LP supplemented with 4 (LP+HMB4), 40 (LP+HMB40), or 80 (LP+HMB80) μmol HMB·kg body wt-1·day-1. In study 2, neonatal pigs were fed for 24 h: LP, LP supplemented with Leu (LP+Leu), or HP diets delivering 9, 18, and 18 mmol Leu·kg body wt-1·day-1, respectively. The upstream signaling molecules that regulate mTORC1 activity were analyzed. mTOR phosphorylation on Ser2448 and Ser2481 was greater in LP+HMB40, LP+HMB80, and LP+Leu than in LP and greater in HP than in HMB-supplemented groups (P < 0.05), whereas HP and LP+Leu were similar. Rheb-mTOR complex formation was lower in LP than in HP (P < 0.05), with no enhancement by HMB or Leu supplementation. The Sestrin2-GATOR2 complex was more abundant in LP than in HP and was reduced by Leu (P < 0.05) but not HMB supplementation. RagA-mTOR and RagC-mTOR complexes were higher in LP+Leu and HP than in LP and HMB groups (P < 0.05). There were no treatment differences in RagB-SH3BP4, Vps34-LRS, and RagD-LRS complex abundances. Phosphorylation of Erk1/2 and TSC2, but not AMPK, was lower in LP than HP (P < 0.05) and unaffected by HMB or Leu supplementation. Our results demonstrate that HMB stimulates mTORC1 activation in neonatal muscle independent of the leucine-sensing pathway mediated by Sestrin2 and the Rag proteins.NEW & NOTEWORTHY Dietary supplementation with either leucine or its metabolite β-hydroxy-β-methylbutyrate (HMB) stimulates protein synthesis in skeletal muscle of the neonatal pig. Our results demonstrate that both leucine and HMB stimulate mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) phosphorylation in neonatal muscle. This leucine-stimulated process involves dissociation of the Sestrin2-GATOR2 complex and increased binding of Rag A/C to mTOR. However, HMB's activation of mTORC1 is independent of this leucine-sensing pathway.
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Affiliation(s)
- Agus Suryawan
- US Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Marko Rudar
- US Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Marta L Fiorotto
- US Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Teresa A Davis
- US Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
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10
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Rivera ME, Lyon ES, Johnson MA, Vaughan RA. Leucine increases mitochondrial metabolism and lipid content without altering insulin signaling in myotubes. Biochimie 2020; 168:124-133. [DOI: 10.1016/j.biochi.2019.10.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/28/2019] [Indexed: 12/29/2022]
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11
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Mugahid DA, Sengul TG, You X, Wang Y, Steil L, Bergmann N, Radke MH, Ofenbauer A, Gesell-Salazar M, Balogh A, Kempa S, Tursun B, Robbins CT, Völker U, Chen W, Nelson L, Gotthardt M. Proteomic and Transcriptomic Changes in Hibernating Grizzly Bears Reveal Metabolic and Signaling Pathways that Protect against Muscle Atrophy. Sci Rep 2019; 9:19976. [PMID: 31882638 PMCID: PMC6934745 DOI: 10.1038/s41598-019-56007-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/05/2019] [Indexed: 12/31/2022] Open
Abstract
Muscle atrophy is a physiological response to disuse and malnutrition, but hibernating bears are largely resistant to this phenomenon. Unlike other mammals, they efficiently reabsorb amino acids from urine, periodically activate muscle contraction, and their adipocytes differentially responds to insulin. The contribution of myocytes to the reduced atrophy remains largely unknown. Here we show how metabolism and atrophy signaling are regulated in skeletal muscle of hibernating grizzly bear. Metabolic modeling of proteomic changes suggests an autonomous increase of non-essential amino acids (NEAA) in muscle and treatment of differentiated myoblasts with NEAA is sufficient to induce hypertrophy. Our comparison of gene expression in hibernation versus muscle atrophy identified several genes differentially regulated during hibernation, including Pdk4 and Serpinf1. Their trophic effects extend to myoblasts from non-hibernating species (including C. elegans), as documented by a knockdown approach. Together, these changes reflect evolutionary favored adaptations that, once translated to the clinics, could help improve atrophy treatment.
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Affiliation(s)
- D A Mugahid
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - T G Sengul
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - X You
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Y Wang
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - L Steil
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - N Bergmann
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - M H Radke
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - A Ofenbauer
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - M Gesell-Salazar
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - A Balogh
- Experimental and Clinical Research Center, Charité & Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - S Kempa
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - B Tursun
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - C T Robbins
- School of the Environment and School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - U Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Greifswald, Greifswald, Germany
| | - W Chen
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - L Nelson
- College of Veterinary Medicine and Department of Veterinary Clinical Science, Washington State University, Pullman, Washington, USA
| | - M Gotthardt
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany. .,Charité Universitätsmedizin Berlin, Berlin, Germany. .,DZHK (German Center for Cardiovascular Research), partner site Berlin, Berlin, Germany.
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12
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Qu YY, Zhao R, Zhang HL, Zhou Q, Xu FJ, Zhang X, Xu WH, Shao N, Zhou SX, Dai B, Zhu Y, Shi GH, Shen YJ, Zhu YP, Han CT, Chang K, Lin Y, Zang WD, Xu W, Ye DW, Zhao SM, Zhao JY. Inactivation of the AMPK-GATA3-ECHS1 Pathway Induces Fatty Acid Synthesis That Promotes Clear Cell Renal Cell Carcinoma Growth. Cancer Res 2019; 80:319-333. [PMID: 31690668 DOI: 10.1158/0008-5472.can-19-1023] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 08/28/2019] [Accepted: 11/01/2019] [Indexed: 02/05/2023]
Abstract
The tumorigenic role and underlying mechanisms of lipid accumulation, commonly observed in many cancers, remain insufficiently understood. In this study, we identified an AMP-activated protein kinase (AMPK)-GATA-binding protein 3 (GATA3)-enoyl-CoA hydratase short-chain 1 (ECHS1) pathway that induces lipid accumulation and promotes cell proliferation in clear cell renal cell carcinoma (ccRCC). Decreased expression of ECHS1, which is responsible for inactivation of fatty acid (FA) oxidation and activation of de novo FA synthesis, positively associated with ccRCC progression and predicted poor patient survival. Mechanistically, ECHS1 downregulation induced FA and branched-chain amino acid (BCAA) accumulation, which inhibited AMPK-promoted expression of GATA3, a transcriptional activator of ECHS1. BCAA accumulation induced activation of mTORC1 and de novo FA synthesis, and promoted cell proliferation. Furthermore, GATA3 expression phenocopied ECHS1 in predicting ccRCC progression and patient survival. The AMPK-GATA3-ECHS1 pathway may offer new therapeutic approaches and prognostic assessment for ccRCC in the clinic. SIGNIFICANCE: These findings uncover molecular mechanisms underlying lipid accumulation in ccRCC, suggesting the AMPK-GATA3-ECHS1 pathway as a potential therapeutic target and prognostic biomarker.
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Affiliation(s)
- Yuan-Yuan Qu
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Key Laboratory of Reproduction Regulation of NPFPC, Institutes of Biomedical Sciences and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Rui Zhao
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China
| | - Hai-Liang Zhang
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Qian Zhou
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China
| | - Fu-Jiang Xu
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Xuan Zhang
- Key Laboratory of Reproduction Regulation of NPFPC, Institutes of Biomedical Sciences and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, P.R. China
| | - Wen-Hao Xu
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Ning Shao
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Shu-Xian Zhou
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Key Laboratory of Reproduction Regulation of NPFPC, Institutes of Biomedical Sciences and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, P.R. China
| | - Bo Dai
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Yao Zhu
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Guo-Hai Shi
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Yi-Jun Shen
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Yi-Ping Zhu
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Cheng-Tao Han
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Kun Chang
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Yan Lin
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Key Laboratory of Reproduction Regulation of NPFPC, Institutes of Biomedical Sciences and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, P.R. China.,Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Wei-Dong Zang
- School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, P.R. China
| | - Wei Xu
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China.,Key Laboratory of Reproduction Regulation of NPFPC, Institutes of Biomedical Sciences and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, P.R. China.,Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Ding-Wei Ye
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China. .,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Shi-Min Zhao
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China. .,Key Laboratory of Reproduction Regulation of NPFPC, Institutes of Biomedical Sciences and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, P.R. China.,Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Jian-Yuan Zhao
- Department of Urology, Fudan University Shanghai Cancer Center, the Obstetrics and Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering and School of Life Sciences, Fudan University, Shanghai, P.R. China. .,Key Laboratory of Reproduction Regulation of NPFPC, Institutes of Biomedical Sciences and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, P.R. China.,Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, P.R. China
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13
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Abstract
Nutrient overload occurs worldwide as a consequence of the modern diet pattern and the physical inactivity that sometimes accompanies it. Cells initiate multiple protective mechanisms to adapt to elevated intracellular metabolites and restore metabolic homeostasis, but irreversible injury to the cells can occur in the event of prolonged nutrient overload. Many studies have advanced the understanding of the different detrimental effects of nutrient overload; however, few reports have made connections and given the full picture of the impact of nutrient overload on cellular metabolism. In this review, detailed changes in metabolic and energy homeostasis caused by chronic nutrient overload, as well as their associations with the development of metabolic disorders, are discussed. Overnutrition-induced changes in key organelles and sensors rewire cellular bioenergetic pathways and facilitate the shift of the metabolic state toward biosynthesis, thereby leading to the onset of various metabolic disorders, which are essentially the downstream manifestations of a misbalanced metabolic equilibrium. Based on these mechanisms, potential therapeutic targets for metabolic disorders and new research directions are proposed.
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Affiliation(s)
- Haowen Qiu
- Department of Nutrition and Health Sciences and Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Vicki Schlegel
- Department of Nutrition and Health Sciences and Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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14
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Schwartz A, Hunschede S, Lacombe RJS, Chatterjee D, Sánchez-Hernández D, Kubant R, Bazinet RP, Hamilton JK, Anderson GH. Acute decrease in plasma testosterone and appetite after either glucose or protein beverages in adolescent males. Clin Endocrinol (Oxf) 2019; 91:295-303. [PMID: 31055857 DOI: 10.1111/cen.14005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/02/2019] [Accepted: 05/03/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Chronic testosterone blood concentrations associate with food intake (FI), but acute effects of testosterone on appetite and effect of protein and glucose consumption on testosterone response have had little examination. METHODS In a randomized, crossover study, twenty-three adolescent (12-18 years old) males were given beverages containing either: (a) whey protein (1 g/kg body weight), (b) glucose (1 g/kg body weight) or (c) a calorie-free control (C). Plasma testosterone, luteinizing hormone (LH), GLP-1 (active), ghrelin (acylated), glucose, insulin and subjective appetite were measured prior (0) and at 20, 35 and 65 minutes after the consumption of the beverage. FI at an ad libitum pizza meal was assessed at 85 minutes. RESULTS Testosterone decreased acutely to 20 minutes after both protein and glucose with the decrease continuing after protein but not glucose to 65 minutes (P = 0.0382). LH was also decreased by both protein and glucose, but glucose had no effect at 20 minutes in contrast to protein (P < 0.001). Plasma testosterone concentration correlated positively with LH (r = 0.58762, P < 0.0001) and negatively with GLP-1 (r = -0.50656, P = 0.0003). No associations with appetite, ghrelin or glycaemic markers were found. Food intake was not affected by treatments. CONCLUSION Protein or glucose ingestion results in acute decreases in both plasma testosterone and LH in adolescent males. The physiological significance of this response remains to be determined as no support for testosterone's role in acute regulation of food intake was found.
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Affiliation(s)
- Alexander Schwartz
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Sascha Hunschede
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Russel John Scott Lacombe
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Diptendu Chatterjee
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Diana Sánchez-Hernández
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ruslan Kubant
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Richard Paul Bazinet
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jill K Hamilton
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Gerald Harvey Anderson
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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15
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Chen X, Xiang L, Jia G, Liu G, Zhao H, Huang Z. Effects of dietary leucine on antioxidant activity and expression of antioxidant and mitochondrial-related genes in longissimus dorsi muscle and liver of piglets. Anim Sci J 2019; 90:990-998. [PMID: 31251457 DOI: 10.1111/asj.13249] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/19/2019] [Accepted: 05/29/2019] [Indexed: 12/28/2022]
Abstract
The study was conducted to investigate the effects of dietary leucine on antioxidant activity and expression of antioxidant- and mitochondrial-related genes in longissimus dorsi muscle and liver of piglets. Three diets were formulated with different levels of supplemented leucine (0%, 0.25%, 0.5%). Results showed that supplementation of 0.25% leucine significantly increased antisuperoxide anion (ASA) and antihydroxyl radical (AHR) levels and activities of total superoxide dismutade (T-SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), and total antioxidant capacity (T-AOC) in serum, longissimus dorsi muscle and liver of piglets as compared with the control group. The SOD2, catalase (CAT), GPx, GST, glutathione reductase (GR), and nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA levels in longissimus dorsi muscle and liver were significantly increased by 0.25% leucine supplementation. However, the malondialdehyde (MDA) content and the mRNA level of Kelch-like ECH-associated protein 1 (Keap1) exhibited an opposite tendency. Additionally, supplementation of 0.25% leucine significantly increased the mRNA levels of mitochondrial-related genes in longissimus dorsi muscle and liver of piglets. Results suggested that supplementation of 0.25% leucine improved antioxidant activity and mitochondrial biogenesis and function of piglets, which was related to the increase in antioxidant enzymes activities and upregulation of expression of antioxidant- and mitochondrial-related genes.
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Affiliation(s)
- Xiaoling Chen
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Lu Xiang
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Gang Jia
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Guangmang Liu
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Hua Zhao
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Zhiqing Huang
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
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16
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Zhang JJ, Chandimali N, Kim N, Kang TY, Kim SB, Kim JS, Wang XZ, Kwon T, Jeong DK. Demethylation and microRNA differential expression regulate plasma-induced improvement of chicken sperm quality. Sci Rep 2019; 9:8865. [PMID: 31222092 PMCID: PMC6586908 DOI: 10.1038/s41598-019-45087-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 05/22/2019] [Indexed: 01/24/2023] Open
Abstract
The sperm quality is a vital economical requisite of poultry production. Our previous study found non-thermal dielectric barrier discharge plasma exposure on fertilized eggs could increase the chicken growth and the male reproduction. However, it is unclear how plasma treatment regulates the reproductive capacity in male chickens. In this study, we used the optimal plasma treatment condition (2.81 W for 2 min) which has been applied on 3.5-day-incubated fertilized eggs in the previous work and investigated the reproductive performance in male chickens aged at 20 and 40 weeks. The results showed that plasma exposure increased sperm count, motility, fertility rate, and fertilization period of male chickens. The sperm quality-promoting effect of plasma treatment was regulated by the significant improvements of adenosine triphosphate production and testosterone level, and by the modulation of reactive oxygen species balance and adenosine monophosphate-activated protein kinase and mammalian target of rapamycin pathway in the spermatozoa. Additionally, the plasma effect suggested that DNA demethylation and microRNA differential expression (a total number of 39 microRNAs were up-regulated whereas 53 microRNAs down-regulated in the testis) regulated the increases of adenosine triphosphate synthesis and testosterone level for promoting the chicken sperm quality. This finding might be beneficial to elevate the fertilization rate and embryo quality for the next generation in poultry breeding.
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Affiliation(s)
- Jiao Jiao Zhang
- Chongqing Key Laboratory of Forage and Herbivore, College of Animal Science and Technology, Southwest University, Chongqing, 400715, P.R. China
| | - Nisansala Chandimali
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Nameun Kim
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Tae Yoon Kang
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Seong Bong Kim
- Plasma Technology Research Center, National Fusion Research Institute, Gunsan-si, Jeollabuk-Do, 54004, Republic of Korea
| | - Ji Su Kim
- Primate Resources Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup-si, Jeonbuk, 56216, Republic of Korea
| | - Xian Zhong Wang
- Chongqing Key Laboratory of Forage and Herbivore, College of Animal Science and Technology, Southwest University, Chongqing, 400715, P.R. China.
| | - Taeho Kwon
- Primate Resources Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup-si, Jeonbuk, 56216, Republic of Korea.
| | - Dong Kee Jeong
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea.
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17
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Johnson MA, Gannon NP, Schnuck JK, Lyon ES, Sunderland KL, Vaughan RA. Leucine, Palmitate, or Leucine/Palmitate Cotreatment Enhances Myotube Lipid Content and Oxidative Preference. Lipids 2019; 53:1043-1057. [DOI: 10.1002/lipd.12126] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 11/23/2018] [Accepted: 12/23/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Michele A. Johnson
- Department of Exercise Science; High Point University; One University Pkwy, High Point NC 27260 USA
| | - Nicholas P. Gannon
- School of Medicine; Medical College of Wisconsin; 8701 W Watertown Plank Rd, Wauwatosa WI 53226 USA
| | - Jamie K. Schnuck
- School of Medicine; Medical College of Wisconsin; 8701 W Watertown Plank Rd, Wauwatosa WI 53226 USA
| | - Emily S. Lyon
- Department of Exercise Science; High Point University; One University Pkwy, High Point NC 27260 USA
| | - Kyle L. Sunderland
- Department of Exercise Science; High Point University; One University Pkwy, High Point NC 27260 USA
| | - Roger A. Vaughan
- Department of Exercise Science; High Point University; One University Pkwy, High Point NC 27260 USA
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18
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Innovative Approach of Non-Thermal Plasma Application for Improving the Growth Rate in Chickens. Int J Mol Sci 2018; 19:ijms19082301. [PMID: 30082605 PMCID: PMC6121326 DOI: 10.3390/ijms19082301] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/03/2018] [Accepted: 08/03/2018] [Indexed: 12/13/2022] Open
Abstract
As an innovative technology in biological applications—non-thermal plasma technique—has recently been applied to living cells and tissues. However, it is unclear whether non-thermal plasma treatment can directly regulate the growth and development of livestock. In this study, we exposed four-day-incubated fertilized eggs to plasma at 11.7 kV for 2 min, which was found to be the optimal condition in respect of highest growth rate in chickens. Interestingly, plasma-treated male chickens conspicuously grew faster than females. Plasma treatment regulated the reactive oxygen species homeostasis by controlling the mitochondrial respiratory complex activity and up-regulating the antioxidant defense system. At the same time, growth metabolism was improved due to the increase of growth hormone and insulin-like growth factor 1 and their receptors expression, and the rise of thyroid hormones and adenosine triphosphate levels through the regulation of demethylation levels of growth and hormone biosynthesis-related genes in the skeletal muscles and thyroid glands. To our knowledge, this study was the first to evaluate the effects of a non-thermal plasma treatment on the growth rate of chickens. This safe strategy might be beneficial to the livestock industry.
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19
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DeBoer ML, Martinson KM, Pampusch MS, Hansen AM, Wells SM, Ward C, Hathaway M. Cultured equine satellite cells as a model system to assess leucine stimulated protein synthesis in horse muscle. J Anim Sci 2018; 96:143-153. [PMID: 29444251 DOI: 10.1093/jas/skx028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 01/25/2018] [Indexed: 12/13/2022] Open
Abstract
Leucine has been shown to stimulate the mammalian/mechanistic target of rapamycin (mTOR) signaling pathway which plays numerous key regulatory roles in cell growth, survival, and metabolism including protein synthesis in a number of species. However, previous work with equine satellite cells has suggested distinct species differences in regards to physiological effects and the magnitude of responses to growth factors and regulators. Because there is limited research available regarding the role of leucine in regulating equine skeletal muscle protein synthesis, the objective of this study was to evaluate the effect of leucine on the mTOR signaling pathway in cultured equine satellite. Protein synthesis was evaluated by measuring the incorporation of [3H] Phenylalanine (3HPhe) in equine satellite cell myotube cultures treated with a leucine titration ranging from 0 to 408 µM. Our results show a 1.8-fold increase (P < 0.02) in protein synthesis at levels slightly greater than those found in the general circulation, 204 and 408 µM when compared to a no leucine control (0 µM). Puromycin incorporation, a nonradioactive surface sensing of translation (SUnSET) methodology, was also measured in cells treated with leucine (LEU; 408 µM), a no-leucine control (CON), and a puromycin-negative vehicle (PURO-). These results demonstrated a 180% increase (P = 0.0056) in puromycin incorporation in LEU compared to CON cultures. To evaluate the mTOR signaling pathway, equine satellite cell myotube cultures were treated with leucine (LEU; 408 µM) or a no-leucine control (CON) in the presence or absence of rapamycin (LR and CR, respectively), an inhibitor of mTOR. The mTOR inhibitor, rapamycin, suppressed phosphorylation of mTOR (P < 0.01) and rS6 (P < 0.01) with an increase in phosphorylation of rS6 in leucine-treated cultures observed when compared to control cultures (P < 0.05). Similarly, there was a 27% increase (P < 0.005) in the hyperphosphorylated γ-form of 4E-BP1 compared to total 4E-BP1 in LEU compared to CON cultures with leucine-induced phosphorylation of 4E-BP1 completely blocked by rapamycin with a smaller decrease observed in CR compared to CON cultures. The major finding of this study was that leucine activated the mTOR translation initiation pathway and increased transcription of global proteins in cultured equine satellite cells. Use of the cell culture system with primary equine muscle cell lines provides the opportunity to distinguish the impact of leucine on muscle and protein synthesis, independent of systemic interactions.
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Affiliation(s)
| | | | - Mary S Pampusch
- Department of Veterinary Biomedical Sciences, University of Minnesota, St. Paul, MN
| | - Abigail M Hansen
- College of Veterinary Medicine, University of Minnesota, St. Paul, MN
| | - Scott M Wells
- Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN
| | - Christie Ward
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN
| | - Marcia Hathaway
- Department of Animal Science, University of Minnesota, St. Paul, MN
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20
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Batista A, Monteiro CP, Borrego R, Matias CN, Teixeira FJ, Valamatos MJ, Oliveira AC, Reis JF, Mendes L, Sardinha LB. Association between whey protein, regional fat mass, and strength in resistance-trained men: a cross-sectional study. Appl Physiol Nutr Metab 2018; 44:7-12. [PMID: 29906403 DOI: 10.1139/apnm-2018-0143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to evaluate the association between whey protein supplementation, body composition, and muscle strength in resistance-trained individuals. Forty-nine healthy males, aged 18 to 35 years and were engaged in resistance training for at least 1 year, were assigned into 2 groups according to whey protein intake (whey - n = 26, age: 30.7 ± 7.4 years, body mass: 75.8 ± 9.0 kg; without whey: n = 23, age: 31.0 ± 7.4 years, body mass: 77.9 ± 9.3 kg). Using a cross-sectional design, a morning assessment of body fat mass (FM) (by dual-energy X-ray absorptiometry) and strength (using 1-repetition maximum for bench press and back squat) was performed. Nutritional assessment was performed by 3-day food records. Regarding nutritional habits, differences between total energy intake (kcal) and estimated energy requirements (kcal) were observed. Results, from raw data or controlling for energy intake, estimated energy requirements, or achieved percentage of energy requirements, showed that whey protein supplementation was inversely correlated with whole-body FM (R = -0.367 (p = 0.010); R = -0.317 (p = 0.049); R = -0.380 (p = 0.011); R = -0.321 (p = 0.047), respectively), trunk FM (R = -0.396 (p = 0.005), R = -0.367 (p = 0.022), R = -0.423 (p = 0.004), R = -0.369 (p = 0.021), respectively) and android FM (R = -0.381 (p = 0.007), R = -0.332 (p = 0.039), R = -0.383 (p = 0.010), R = -0.336 (p = 0.036), respectively). No correlations were found between muscle strength outcomes and whey protein supplementation. The present data suggest that whey protein ingestion has a positive association with whole-body and regional (trunk and android) FM.
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Affiliation(s)
- Ana Batista
- a Dietetics and Nutrition Department, Escola Superior de Tecnologia da Saúde de Lisboa, Av. Dom João II Lote 4.69.01, 1990-096, Lisboa, Portugal
| | - Cristina P Monteiro
- b Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,c CIPER-Interdisciplinary Center for the Study of Human Performance, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal
| | - Rute Borrego
- a Dietetics and Nutrition Department, Escola Superior de Tecnologia da Saúde de Lisboa, Av. Dom João II Lote 4.69.01, 1990-096, Lisboa, Portugal
| | - Catarina N Matias
- b Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,c CIPER-Interdisciplinary Center for the Study of Human Performance, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,d Exercise and Health Laboratory, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal
| | - Filipe J Teixeira
- b Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal
| | - Maria J Valamatos
- c CIPER-Interdisciplinary Center for the Study of Human Performance, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,e Neuromuscular Research Lab, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,f Laboratory of Biomechanics and Functional Morphology, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal
| | - Ana C Oliveira
- g Nutrition Department, Instituto Superior de Ciências da Saúde Egas Moniz, Campus Universitário, Quinta da Granja, 2829-511, Monte de Caparica, Almada, Portugal
| | - Joana F Reis
- b Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,c CIPER-Interdisciplinary Center for the Study of Human Performance, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,h Universidade Europeia, Quinta do Bom Nome, Estr. Correia 53, 1500-210 Lisbon, Portugal
| | - Lino Mendes
- a Dietetics and Nutrition Department, Escola Superior de Tecnologia da Saúde de Lisboa, Av. Dom João II Lote 4.69.01, 1990-096, Lisboa, Portugal
| | - Luís B Sardinha
- c CIPER-Interdisciplinary Center for the Study of Human Performance, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,i Exercise and Health Laboratory, Faculty of Human Kinetics, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal
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Zhang JJ, Do HL, Chandimali N, Lee SB, Mok YS, Kim N, Kim SB, Kwon T, Jeong DK. Non-thermal plasma treatment improves chicken sperm motility via the regulation of demethylation levels. Sci Rep 2018; 8:7576. [PMID: 29765100 PMCID: PMC5953930 DOI: 10.1038/s41598-018-26049-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/03/2018] [Indexed: 12/25/2022] Open
Abstract
The quality of avian semen is an important economic trait in poultry production. The present study examines the in vitro effects of non-thermal dielectric barrier discharge plasma on chicken sperm to determine the plasma conditions that can produce the optimum sperm quality. Exposure to 11.7 kV of plasma for 20 s is found to produce maximum sperm motility by controlling the homeostasis of reactive oxygen species and boosting the release of adenosine triphosphate and respiratory enzyme activity in the mitochondria. However, prolonged exposure or further increase in plasma potential impairs the sperm quality in a time- and dose-dependent manner. Optimal plasma treatment of sperm results in upregulated mRNA and protein expression of antioxidant defense-related and energetic metabolism-related genes by increasing their demethylation levels. However, 27.6 kV of plasma exerts significant adverse effects. Thus, our findings indicate that appropriate plasma exposure conditions improve chicken sperm motility by regulating demethylation levels of genes involved in antioxidant defense and energetic metabolism.
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Affiliation(s)
- Jiao Jiao Zhang
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Huynh Luong Do
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Nisansala Chandimali
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Sang Baek Lee
- Department of Chemical and Biological Engineering, Jeju National University, Jeju, 63243, Republic of Korea
| | - Young Sun Mok
- Department of Chemical and Biological Engineering, Jeju National University, Jeju, 63243, Republic of Korea
| | - Nameun Kim
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Seong Bong Kim
- Plasma Technology Research Center, National Fusion Research Institute, Gunsan-si, Jeollabuk-Do, 54004, Republic of Korea
| | - Taeho Kwon
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Subtropical/Tropical Organism Gene Bank, Jeju National University, Jeju, 63243, Republic of Korea.
| | - Dong Kee Jeong
- Laboratory of Animal Genetic Engineering and Stem Cell Biology, Department of Advanced Convergence Technology and Science, Jeju National University, Jeju, 63243, Republic of Korea. .,Laboratory of Animal Genetic Engineering and Stem Cell Biology, Subtropical/Tropical Organism Gene Bank, Jeju National University, Jeju, 63243, Republic of Korea.
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22
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Gannon NP, Schnuck JK, Vaughan RA. BCAA Metabolism and Insulin Sensitivity - Dysregulated by Metabolic Status? Mol Nutr Food Res 2018; 62:e1700756. [PMID: 29377510 DOI: 10.1002/mnfr.201700756] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 12/29/2017] [Indexed: 12/18/2022]
Abstract
Branched-chain amino acids (BCAAs) appear to influence several synthetic and catabolic cellular signaling cascades leading to altered phenotypes in mammals. BCAAs are most notably known to increase protein synthesis through modulating protein translation, explaining their appeal to resistance and endurance athletes for muscle hypertrophy, expedited recovery, and preservation of lean body mass. In addition to anabolic effects, BCAAs may increase mitochondrial content in skeletal muscle and adipocytes, possibly enhancing oxidative capacity. However, elevated circulating BCAA levels have been correlated with severity of insulin resistance. It is hypothesized that elevated circulating BCAAs observed in insulin resistance may result from dysregulated BCAA degradation. This review summarizes original reports that investigated the ability of BCAAs to alter glucose uptake in consequential cell types and experimental models. The review also discusses the interplay of BCAAs with other metabolic factors, and the role of excess lipid (and possibly energy excess) in the dysregulation of BCAA catabolism. Lastly, this article provides a working hypothesis of the mechanism(s) by which lipids may contribute to altered BCAA catabolism, which often accompanies metabolic disease.
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Affiliation(s)
| | - Jamie K Schnuck
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI
| | - Roger A Vaughan
- Department of Exercise Science, High Point University, High Point, NC
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23
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mTORC1 as the main gateway to autophagy. Essays Biochem 2017; 61:565-584. [PMID: 29233869 PMCID: PMC5869864 DOI: 10.1042/ebc20170027] [Citation(s) in RCA: 339] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/19/2017] [Accepted: 10/20/2017] [Indexed: 12/16/2022]
Abstract
Cells and organisms must coordinate their metabolic activity with changes in their environment to ensure their growth only when conditions are favourable. In order to maintain cellular homoeostasis, a tight regulation between the synthesis and degradation of cellular components is essential. At the epicentre of the cellular nutrient sensing is the mechanistic target of rapamycin complex 1 (mTORC1) which connects environmental cues, including nutrient and growth factor availability as well as stress, to metabolic processes in order to preserve cellular homoeostasis. Under nutrient-rich conditions mTORC1 promotes cell growth by stimulating biosynthetic pathways, including synthesis of proteins, lipids and nucleotides, and by inhibiting cellular catabolism through repression of the autophagic pathway. Its close signalling interplay with the energy sensor AMP-activated protein kinase (AMPK) dictates whether the cell actively favours anabolic or catabolic processes. Underlining the role of mTORC1 in the coordination of cellular metabolism, its deregulation is linked to numerous human diseases ranging from metabolic disorders to many cancers. Although mTORC1 can be modulated by a number of different inputs, amino acids represent primordial cues that cannot be compensated for by any other stimuli. The understanding of how amino acids signal to mTORC1 has increased considerably in the last years; however this area of research remains a hot topic in biomedical sciences. The current ideas and models proposed to explain the interrelationship between amino acid sensing, mTORC1 signalling and autophagy is the subject of the present review.
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Nakai N, Kawano F, Murakami T, Nakata K, Higashida K. Leucine supplementation after mechanical stimulation activates protein synthesis via L-type amino acid transporter 1 in vitro. J Cell Biochem 2017; 119:2094-2101. [PMID: 28856713 DOI: 10.1002/jcb.26371] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/23/2017] [Indexed: 11/11/2022]
Abstract
Branched-chain amino acid supplements consumed following exercise are widely used to increase muscle mass. Although both exercise (ie, mechanical stimulation) and branched-chain amino acid leucine supplementation have been reported to stimulate muscle protein synthesis by activating the mammalian target of rapamycin (mTOR) signaling pathway independently, the mechanisms underlying their synergistic effects are largely unknown. Utilizing cultured differentiated C2C12 myotubes, we established a combination treatment model in which the cells were subjected to cyclic uniaxial mechanical stretching (4 h, 15%, 1 Hz) followed by stimulation with 2 mM leucine for 45 min. Phosphorylation of p70 S6 kinase (p70S6K), an mTOR-regulated marker of protein translation initiation, was significantly increased following mechanical stretching alone but returned to the baseline after 4 h. Leucine supplementation further increased p70S6K phosphorylation, with a greater increase observed in the stretched cells than in the non-stretched cells. Notably, the expression of L-type amino acid transporter 1 (LAT1), a stimulator of the mTOR pathway, was also increased by mechanical stretching, and siRNA-mediated knockdown partially attenuated leucine-induced p70S6K phosphorylation. These results suggest that mechanical stretching promotes LAT1 expression and, consequently, amino acid uptake, leading to enhanced leucine-induced activation of protein synthesis. LAT1 has been demonstrated to be a point of crosstalk between exercise- and nutrition-induced skeletal muscle growth.
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Affiliation(s)
- Naoya Nakai
- Department of Nutrition, University of Shiga Prefecture, Hikone, Shiga, Japan
| | - Fuminori Kawano
- Graduate School of Health Sciences, Matsumoto University, Matsumoto, Nagano, Japan
| | - Taro Murakami
- Department of Nutrition, Shigakkan University, Ohbu, Aichi, Japan
| | - Ken Nakata
- Medicine for Sports and Performing Arts, Graduate School of Medicine, Osaka University, Toyonaka, Osaka, Japan
| | - Kazuhiko Higashida
- Department of Nutrition, University of Shiga Prefecture, Hikone, Shiga, Japan
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25
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Chalvon-Demersay T, Even PC, Chaumontet C, Piedcoq J, Viollet B, Gaudichon C, Tomé D, Foretz M, Azzout-Marniche D. Modifying the Dietary Carbohydrate-to-Protein Ratio Alters the Postprandial Macronutrient Oxidation Pattern in Liver of AMPK-Deficient Mice. J Nutr 2017; 147:1669-1676. [PMID: 28747486 DOI: 10.3945/jn.117.250803] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 03/28/2017] [Accepted: 06/13/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Hepatic AMP-activated kinase (AMPK) activity is sensitive to the dietary carbohydrate-to-protein ratio. However, the role of AMPK in metabolic adaptations to variations in dietary macronutrients remains poorly understood.Objective: The objective of this study was to determine the role of hepatic AMPK in the adaptation of energy metabolism in response to modulation of the dietary carbohydrate-to-protein ratio.Methods: Male 7-wk-old wild-type (WT) and liver AMPK-deficient (knockout) mice were fed either a normal-protein and normal-carbohydrate diet (NP-NC; 14% protein, 76% carbohydrate on an energy basis), a low-protein and high-carbohydrate diet (LP-HC; 5% protein, 85% carbohydrate), or a high-protein and low-carbohydrate diet (HP-LC; 55% protein, 35% carbohydrate) for 3 wk. During this period, after an overnight fast, metabolic parameters were measured and indirect calorimetry was performed in mice during the first hours after refeeding a 1-g calibrated meal of their own diet in order to investigate lipid and carbohydrate metabolism.Results: Knockout mice fed an LP-HC or HP-LC meal exhibited 24% and 8% lower amplitudes in meal-induced carbohydrate and lipid oxidation changes. By contrast, knockout mice fed an NP-NC meal displayed normal carbohydrate and lipid oxidation profiles. These mice exhibited a transient increase in hepatic triglycerides and a decrease in hepatic glycogen. These changes were associated with a 650% higher secretion of fibroblast growth factor 21 (FGF21) 2 h after refeeding.Conclusions: The consequences of hepatic AMPK deletion depend on the dietary carbohydrate-to-protein ratio. In mice fed the NP-NC diet, deletion of AMPK in the liver led to an adaptation of liver metabolism resulting in increased secretion of FGF21. These changes possibly compensated for the absence of hepatic AMPK, as these mice exhibited normal postprandial changes in carbohydrate and lipid oxidation. By contrast, in mice fed the LP-HC and HP-LC diets, the lack of adjustment in liver metabolism in knockout mice resulted in a metabolic inflexibility, leading to a reduced amplitude of meal-induced changes in carbohydrate and lipid oxidation.
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Affiliation(s)
- Tristan Chalvon-Demersay
- UMR Nutrition Physiology and Ingestive Behavior, AgroParisTech, INRA, Paris-Saclay University, Paris, France
| | - Patrick C Even
- UMR Nutrition Physiology and Ingestive Behavior, AgroParisTech, INRA, Paris-Saclay University, Paris, France
| | - Catherine Chaumontet
- UMR Nutrition Physiology and Ingestive Behavior, AgroParisTech, INRA, Paris-Saclay University, Paris, France
| | - Julien Piedcoq
- UMR Nutrition Physiology and Ingestive Behavior, AgroParisTech, INRA, Paris-Saclay University, Paris, France
| | - Benoit Viollet
- French National Institute of Health and Medical Research, U1016, Cochin Institute, Paris, France.,The National Center for Scientific Research, UMR8104, Paris, France; and.,Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - Claire Gaudichon
- UMR Nutrition Physiology and Ingestive Behavior, AgroParisTech, INRA, Paris-Saclay University, Paris, France
| | - Daniel Tomé
- UMR Nutrition Physiology and Ingestive Behavior, AgroParisTech, INRA, Paris-Saclay University, Paris, France;
| | - Marc Foretz
- French National Institute of Health and Medical Research, U1016, Cochin Institute, Paris, France.,The National Center for Scientific Research, UMR8104, Paris, France; and.,Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - Dalila Azzout-Marniche
- UMR Nutrition Physiology and Ingestive Behavior, AgroParisTech, INRA, Paris-Saclay University, Paris, France
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Kolanu BR, Boddula V, Vadakedath S, Kandi V. Amino Acid (Leucine) Chromatography: A Study of Branched-Chain Aminoaciduria in Type 2 Diabetes. Cureus 2017; 9:e1091. [PMID: 28413737 PMCID: PMC5391057 DOI: 10.7759/cureus.1091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION Diabetes is a disease characterized by insulin deficiency resulting in glucose intolerance and in abnormalities of other metabolic fuels including protein. Recently, a number of studies have revealed that branched-chain amino acids (BCAAs) (leucine, isoleucine, and valine) play an important role in the regulation of protein synthesis by activating mammalian target of rapamycin (mTOR) in pancreatic β cells. BCAAs have positive effects on the regulation of glucose homeostasis. Leucine is an important nutrient signal as evidenced by recent observations, which showed increased fasting concentrations of circulating BCAAs being associated with an increased risk of type 2 diabetes (T2D) and insulin resistance in humans. Leucine seems to have direct effects on hypothalamic and brainstem functioning involved in satiety, which can potentially contribute to obesity and T2D. A number of observational studies indicate that elevated activity of BCAAs could be associated with poor metabolic health and T2D complications. Although these associations were consistently observed in humans, the mechanisms underlying this relationship remain to be completely understood. In this study, we have attempted to evaluate urinary excretion of leucine among patients of T2D and compared them with healthy controls by using a low-cost and non-invasive amino acid chromatography technique. METHODS The study was carried out in the Department of Biochemistry, Central Research Unit, Prathima Institute of Medical Sciences (PIMS), Karimnagar, Telangana, India, during the period between July and September 2016. A group of 55 normal healthy subjects (control group A), and 55 patients suffering from T2D on treatment (test group B), were enrolled in the study. The urine samples were collected from normal and T2D subjects. Thin-layer chromatography (TLC) for leucine was performed on all the urine samples. RESULTS A strong correlation (p=0.0004) was found between the urinary excretion of leucine among the control (Rf=0.174 ±0.089) and T2D (Rf=0.247 ±0.030) patients. CONCLUSION Excretion of BCAAs (leucine) in detectable and increased quantities reflect the presence of an altered metabolic state attributable to T2D, which in turn could lead to early diabetic complications. This method (TLC), being non-invasive and cost-effective, could be recommended for assessing the progression and management of type 2 diabetes patients.
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Huang Q, Xu W, Bai KW, He JT, Ahmad H, Zhou L, Zhang LL, Wang T. Protective effects of leucine on redox status and mitochondrial-related gene abundance in the jejunum of intrauterine growth-retarded piglets during early weaning period. Arch Anim Nutr 2017; 71:93-107. [PMID: 28118753 DOI: 10.1080/1745039x.2017.1279712] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The aim of this study was to investigate the effects of dietary supplementation with 0.35% l-leucine on redox status and gene abundance relating to mitochondrial biogenesis and function in the jejunum of intrauterine growth-retarded (IUGR) piglets during early weaning period. According to a 2 × 2 factorial arrangement, 16 IUGR and 16 normal body weight (NBW) piglets were fed a basal diet without l-leucine supplementation or a basal diet plus 0.35% l-leucine supplementation from the age of 14 to 35 d. The results showed that compared with NBW piglets, IUGR piglets had a lower (p < 0.05) jejunal DNA concentration, a reduced (p < 0.05) manganese superoxide dismutase (MnSOD) and total antioxidant capability (T-AOC) activities and mitochondrial DNA content in the jejunum. Leucine supplementation increased (p < 0.05) MnSOD and T-AOC activities and decreased (p < 0.05) the malondialdehyde content in the jejunum of IUGR piglets. The mRNA gene abundance of nuclear respiratory factor-1 (NRF1), mitochondrial transcription factor A (TFAM), ATP synthase (ATPs), cytochrome c oxidase V (CcOX V), cytochrome c and glucokinase in the jejunum of IUGR piglets was reduced (p < 0.05) compared with NBW piglets. However, NRF1, peroxisome proliferation-activated receptor gamma coactivator-1 alpha, TFAM, ATPs and CcOX I mRNA gene abundance in the jejunum of IUGR piglets were increased (p < 0.05) by diets supplemented with leucine. These data indicate that leucine supplementation has therapeutic potential for attenuating intestinal oxidative stress and mitochondrial dysfunction in IUGR piglets during the early period of life via increasing enzyme activities and up-regulating mRNA gene abundance.
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Affiliation(s)
- Qiang Huang
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Wen Xu
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Kai-Wen Bai
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Jin-Tian He
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Hussain Ahmad
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Le Zhou
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Li-Li Zhang
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
| | - Tian Wang
- a Department of Animal Nutrition and Feed Science , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing , China
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28
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A systems study reveals concurrent activation of AMPK and mTOR by amino acids. Nat Commun 2016; 7:13254. [PMID: 27869123 PMCID: PMC5121333 DOI: 10.1038/ncomms13254] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 09/13/2016] [Indexed: 12/17/2022] Open
Abstract
Amino acids (aa) are not only building blocks for proteins, but also signalling molecules, with the mammalian target of rapamycin complex 1 (mTORC1) acting as a key mediator. However, little is known about whether aa, independently of mTORC1, activate other kinases of the mTOR signalling network. To delineate aa-stimulated mTOR network dynamics, we here combine a computational–experimental approach with text mining-enhanced quantitative proteomics. We report that AMP-activated protein kinase (AMPK), phosphatidylinositide 3-kinase (PI3K) and mTOR complex 2 (mTORC2) are acutely activated by aa-readdition in an mTORC1-independent manner. AMPK activation by aa is mediated by Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ). In response, AMPK impinges on the autophagy regulators Unc-51-like kinase-1 (ULK1) and c-Jun. AMPK is widely recognized as an mTORC1 antagonist that is activated by starvation. We find that aa acutely activate AMPK concurrently with mTOR. We show that AMPK under aa sufficiency acts to sustain autophagy. This may be required to maintain protein homoeostasis and deliver metabolite intermediates for biosynthetic processes. mTORC1 is known to mediate the signalling activity of amino acids. Here, the authors combine modelling with experiments and find that amino acids acutely stimulate mTORC2, IRS/PI3K and AMPK, independently of mTORC1. AMPK activation through CaMKKβ sustains autophagy under non-starvation conditions.
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29
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Song F, Xu D, Mai K, Zhou H, Xu W, He G. Comparative Study on the Cellular and Systemic Nutrient Sensing and Intermediary Metabolism after Partial Replacement of Fishmeal by Meat and Bone Meal in the Diet of Turbot (Scophthalmus maximus L.). PLoS One 2016; 11:e0165708. [PMID: 27802317 PMCID: PMC5089717 DOI: 10.1371/journal.pone.0165708] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 10/17/2016] [Indexed: 01/16/2023] Open
Abstract
This study was designed to examine the cellular and systemic nutrient sensing mechanisms as well as the intermediary metabolism responses in turbot (Scophthalmus maximus L.) fed with fishmeal diet (FM diet), 45% of FM replaced by meat and bone meal diet (MBM diet) or MBM diet supplemented with essential amino acids to match the amino acid profile of FM diet (MBM+AA diet). During the one month feeding trial, feed intake was not affected by the different diets. However, MBM diet caused significant reduction of specific growth rate and nutrient retentions. Compared with the FM diet, MBM diet down-regulated target of rapamycin (TOR) and insulin-like growth factor (IGFs) signaling pathways, whereas up-regulated the amino acid response (AAR) signaling pathway. Moreover, MBM diet significantly decreased glucose and lipid anabolism, while increased muscle protein degradation and lipid catabolism in liver. MBM+AA diet had no effects on improvement of MBM diet deficiencies. Compared with fasted, re-feeding markedly activated the TOR signaling pathway, IGF signaling pathway and glucose, lipid metabolism, while significantly depressed the protein degradation signaling pathway. These results thus provided a comprehensive display of molecular responses and a better explanation of deficiencies generated after fishmeal replacement by other protein sources.
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Affiliation(s)
- Fei Song
- The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture), Ocean University of China, Qingdao, 266003, China
- The Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Dandan Xu
- The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture), Ocean University of China, Qingdao, 266003, China
- The Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Kangsen Mai
- The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture), Ocean University of China, Qingdao, 266003, China
- The Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Huihui Zhou
- The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture), Ocean University of China, Qingdao, 266003, China
- The Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Wei Xu
- The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture), Ocean University of China, Qingdao, 266003, China
| | - Gen He
- The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture), Ocean University of China, Qingdao, 266003, China
- The Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
- * E-mail:
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30
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Schnuck JK, Johnson MA, Gould LM, Gannon NP, Vaughan RA. Acute β-Hydroxy-β-Methyl Butyrate Suppresses Regulators of Mitochondrial Biogenesis and Lipid Oxidation While Increasing Lipid Content in Myotubes. Lipids 2016; 51:1127-1136. [PMID: 27600148 DOI: 10.1007/s11745-016-4193-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/25/2016] [Indexed: 01/30/2023]
Abstract
Leucine modulates synthetic and degradative pathways in muscle, possibly providing metabolic benefits for both athletes and diseased populations. Leucine has become popular among athletes for improving performance and body composition, however little is known about the metabolic effects of the commonly consumed leucine-derived metabolite β-hydroxy-β-methyl butyrate (HMB). Our work measured the effects of HMB on metabolic protein expression, mitochondrial content and metabolism, as well as lipid content in skeletal muscle cells. Specifically, cultured C2C12 myotubes were treated with either a control or HMB ranging from 6.25 to 25 μM for 24 h and mRNA and/or protein expression, oxygen consumption, glucose uptake, and lipid content were measured. Contrary to leucine's stimulatory effect on metabolism, HMB-treated cells exhibited significantly reduced regulators of lipid oxidation including peroxisome proliferator-activated receptor alpha (PPARα) and PPARβ/δ, as well as downstream target carnitine palmitoyl transferase, without alterations in glucose or palmitate oxidation. Furthermore, HMB significantly inhibited activation of the master regulator of energetics, AMP-activated protein kinase. As a result, HMB-treated cells also displayed reduced total mitochondrial content compared with true control or cells equivocally treated with leucine. Additionally, HMB treatment amplified markers of lipid biosynthesis (PPARγ and fatty acid synthase) as well as consistently promoted elevated total lipid content versus control cells. Collectively, our results demonstrate that HMB did not improve mitochondrial metabolism or content, and may promote elevated cellular lipid content possibly through heightened PPARγ expression. These observations suggest that HMB may be most beneficial for populations interested in stimulating anabolic cellular processes.
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Affiliation(s)
- Jamie K Schnuck
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Michele A Johnson
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Lacey M Gould
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Nicholas P Gannon
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Roger A Vaughan
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA.
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Regulation and function of AMPK in physiology and diseases. Exp Mol Med 2016; 48:e245. [PMID: 27416781 PMCID: PMC4973318 DOI: 10.1038/emm.2016.81] [Citation(s) in RCA: 670] [Impact Index Per Article: 83.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 04/23/2016] [Accepted: 04/26/2016] [Indexed: 12/18/2022] Open
Abstract
5′-adenosine monophosphate (AMP)-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that was originally identified as the key player in maintaining cellular energy homeostasis. Intensive research over the last decade has identified diverse molecular mechanisms and physiological conditions that regulate the AMPK activity. AMPK regulates diverse metabolic and physiological processes and is dysregulated in major chronic diseases, such as obesity, inflammation, diabetes and cancer. On the basis of its critical roles in physiology and pathology, AMPK is emerging as one of the most promising targets for both the prevention and treatment of these diseases. In this review, we discuss the current understanding of the molecular and physiological regulation of AMPK and its metabolic and physiological functions. In addition, we discuss the mechanisms underlying the versatile roles of AMPK in diabetes and cancer.
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The Effect of Post-Resistance Exercise Amino Acids on Plasma MCP-1 and CCR2 Expression. Nutrients 2016; 8:nu8070409. [PMID: 27384580 PMCID: PMC4963885 DOI: 10.3390/nu8070409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 06/22/2016] [Accepted: 06/29/2016] [Indexed: 12/22/2022] Open
Abstract
The recruitment and infiltration of classical monocytes into damaged muscle is critical for optimal tissue remodeling. This study examined the effects of an amino acid supplement on classical monocyte recruitment following an acute bout of lower body resistance exercise. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) ingested supplement (SUPP) or placebo (PL) immediately post-exercise in a randomized, cross-over design. Blood samples were obtained at baseline (BL), immediately (IP), 30-min (30P), 1-h (1H), 2-h (2H), and 5-h (5H) post-exercise to assess plasma concentrations of monocyte chemoattractant protein 1 (MCP-1), myoglobin, cortisol and insulin concentrations; and expressions of C-C chemokine receptor-2 (CCR2), and macrophage-1 antigen (CD11b) on classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Changes in myoglobin, cortisol, and insulin concentrations were similar between treatments. Compared to PL, plasma MCP-1 was “very likely greater” (98.1% likelihood effect) in SUPP at 2H. CCR2 expression was “likely greater” at IP (84.9% likelihood effect), “likely greater” at 1H (87.7% likelihood effect), “very likely greater” at 2H (97.0% likelihood effect), and “likely greater” at 5H (90.1% likelihood effect) in SUPP, compared to PL. Ingestion of SUPP did not influence CD11b expression. Ingestion of an amino acid supplement immediately post-exercise appears to help maintain plasma MCP-1 concentrations and augment CCR2 expression in resistance trained men.
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Leucine stimulates PPARβ/δ-dependent mitochondrial biogenesis and oxidative metabolism with enhanced GLUT4 content and glucose uptake in myotubes. Biochimie 2016; 128-129:1-7. [PMID: 27345255 DOI: 10.1016/j.biochi.2016.06.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/15/2016] [Indexed: 02/08/2023]
Abstract
Leucine stimulates anabolic and catabolic processes in skeletal muscle, however little is known about the effects of leucine on peroxisome proliferator-activated receptor (PPAR) activity. This work characterized the effects of 24-h leucine treatment on metabolic parameters and protein expression in cultured myotubes. Leucine significantly increased PPARβ/δ expression as well as markers of mitochondrial biogenesis, leading to significantly increased mitochondrial content and oxidative metabolism in a PPARβ/δ-dependent manner. However, leucine-treated cells did not display significant alterations in uncoupling protein expression or oxygen consumed per relative mitochondrial content suggesting leucine-mediated increases in oxidative metabolism are a function of increased mitochondrial content and not altered mitochondrial efficiency. Leucine treatment also increased GLUT4 content and glucose uptake as well as PPARγ and FAS expression leading to increased total lipid content. Leucine appears to activate PPAR activity leading to increased mitochondrial biogenesis and elevated substrate oxidation, while simultaneously promoting substrate/lipid storage and protein synthesis.
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Leucine alleviates dexamethasone-induced suppression of muscle protein synthesis via synergy involvement of mTOR and AMPK pathways. Biosci Rep 2016; 36:BSR20160096. [PMID: 27129299 PMCID: PMC5293580 DOI: 10.1042/bsr20160096] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 04/28/2016] [Indexed: 12/19/2022] Open
Abstract
Both mTOR and AMPK pathways are involved in the DEX-induced suppression of protein synthesis in muscle cells. Leucine supplementation relieves DEX-induced inhibition on protein synthesis by evoking mTOR and suppressing AMPK pathway. Glucocorticoids (GCs) are negative muscle protein regulators that contribute to the whole-body catabolic state during stress. Mammalian target of rapamycin (mTOR)-signalling pathway, which acts as a central regulator of protein metabolism, can be activated by branched-chain amino acids (BCAA). In the present study, the effect of leucine on the suppression of protein synthesis induced by GCs and the pathway involved were investigated. In vitro experiments were conducted using cultured C2C12 myoblasts to study the effect of GCs on protein synthesis, and the involvement of mTOR pathway was investigated as well. After exposure to dexamethasone (DEX, 100 μmol/l) for 24 h, protein synthesis in muscle cells was significantly suppressed (P<0.05), the phosphorylations of mTOR, ribosomal protein S6 protein kinase 1 (p70s6k1) and eukaryotic initiation factor 4E binding protein 1 (4EBP1) were significantly reduced (P<0.05). Leucine supplementation (5 mmol/l, 10 mmol/l and 15 mmol/l) for 1 h alleviated the suppression of protein synthesis induced by DEX (P<0.05) and was accompanied with the increased phosphorylation of mTOR and decreased phosphorylation of AMPK (P<0.05). Branched-chain amino transferase 2 (BCAT2) mRNA level was not influenced by DEX (P>0.05) but was increased by leucine supplementation at a dose of 5 mmol/l (P<0.05).
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Bourgoin-Voillard S, Goron A, Seve M, Moinard C. Regulation of the proteome by amino acids. Proteomics 2016; 16:831-46. [DOI: 10.1002/pmic.201500347] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 12/30/2015] [Accepted: 01/12/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Sandrine Bourgoin-Voillard
- Plateforme de Protéomique PROMETHEE; IAB; University Grenoble Alpes; Grenoble France
- Plateforme de Protéomique PROMETHEE, Institut de Biologie et de Pathologie; CHU de Grenoble; Grenoble France
- Plateforme de Protéomique PROMETHEE; IAB; INSERM; Grenoble France
| | - Arthur Goron
- Laboratory of Fundamental and Applied Bioenergetics (LBFA); University Grenoble Alpes; Grenoble France
- Laboratory of Fundamental and Applied Bioenergetics (LBFA); INSERM; Grenoble France
| | - Michel Seve
- Plateforme de Protéomique PROMETHEE; IAB; University Grenoble Alpes; Grenoble France
- Plateforme de Protéomique PROMETHEE, Institut de Biologie et de Pathologie; CHU de Grenoble; Grenoble France
- Plateforme de Protéomique PROMETHEE; IAB; INSERM; Grenoble France
| | - Christophe Moinard
- Laboratory of Fundamental and Applied Bioenergetics (LBFA); University Grenoble Alpes; Grenoble France
- Laboratory of Fundamental and Applied Bioenergetics (LBFA); INSERM; Grenoble France
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Wessels AG, Kluge H, Hirche F, Kiowski A, Schutkowski A, Corrent E, Bartelt J, König B, Stangl GI. High Leucine Diets Stimulate Cerebral Branched-Chain Amino Acid Degradation and Modify Serotonin and Ketone Body Concentrations in a Pig Model. PLoS One 2016; 11:e0150376. [PMID: 26930301 PMCID: PMC4773154 DOI: 10.1371/journal.pone.0150376] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 02/12/2016] [Indexed: 01/06/2023] Open
Abstract
In addition to its role as an essential protein component, leucine (Leu) displays several other metabolic functions such as activation of protein synthesis. This property makes it an interesting amino acid for the therapy of human muscle atrophy and for livestock production. However, Leu can stimulate its own degradation via the branched-chain keto acid dehydrogenase complex (BCKDH). To examine the response of several tissues to excessive Leu, pigs were fed diets containing two- (L2) and four-fold (L4) higher Leu contents than the recommended amount (control). We found that the L4 diet led to a pronounced increase in BCKDH activity in the brain (2.5-fold, P < 0.05), liver (1.8-fold, P < 0.05) and cardiac muscle (1.7-fold, P < 0.05), whereas we found no changes in enzyme activity in the pancreas, skeletal muscle, adipose tissue and intestinal mucosa. The L2 diet had only weak effects on BCKDH activity. Both high Leu diets reduced the concentrations of free valine and isoleucine in nearly all tissues. In the brain, high Leu diets modified the amount of tryptophan available: for serotonin synthesis. Compared to the controls, pigs treated with the high Leu diets consumed less food, showed increased plasma concentrations of 3-hydroxybutyrate and reduced levels of circulating serotonin. In conclusion, excessive Leu can stimulate BCKDH activity in several tissues, including the brain. Changes in cerebral tryptophan, along with the changes in amino acid-derived metabolites in the plasma may limit the use of high Leu diets to treat muscle atrophy or to increase muscle growth.
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Affiliation(s)
- Anna G. Wessels
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Holger Kluge
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Frank Hirche
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Andreas Kiowski
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Alexandra Schutkowski
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | | | - Jörg Bartelt
- Lohmann Animal Nutrition GmbH, 27472, Cuxhaven, Germany
| | - Bettina König
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Gabriele I. Stangl
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
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Azizi S, Nematollahi MA, Mojazi Amiri B, Vélez EJ, Lutfi E, Navarro I, Capilla E, Gutiérrez J. Lysine and Leucine Deficiencies Affect Myocytes Development and IGF Signaling in Gilthead Sea Bream (Sparus aurata). PLoS One 2016; 11:e0147618. [PMID: 26808650 PMCID: PMC4725776 DOI: 10.1371/journal.pone.0147618] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 01/06/2016] [Indexed: 11/18/2022] Open
Abstract
Optimizing aquaculture production requires better knowledge of growth regulation and improvement in diet formulation. A great effort has been made to replace fish meal for plant protein sources in aquafeeds, making necessary the supplementation of such diets with crystalline amino acids (AA) to cover the nutritional requirements of each species. Lysine and Leucine are limiting essential AA in fish, and it has been demonstrated that supplementation with them improves growth in different species. However, the specific effects of AA deficiencies in myogenesis are completely unknown and have only been studied at the level of hepatic metabolism. It is well-known that the TOR pathway integrates the nutritional and hormonal signals to regulate protein synthesis and cell proliferation, to finally control muscle growth, a process also coordinated by the expression of myogenic regulatory factors (MRFs). This study aimed to provide new information on the impact of Lysine and Leucine deficiencies in gilthead sea bream cultured myocytes examining their development and the response of insulin-like growth factors (IGFs), MRFs, as well as key molecules involved in muscle growth regulation like TOR. Leucine deficiency did not cause significant differences in most of the molecules analyzed, whereas Lysine deficiency appeared crucial in IGFs regulation, decreasing significantly IGF-I, IGF-II and IGF-IRb mRNA levels. This treatment also down-regulated the gene expression of different MRFs, including Myf5, Myogenin and MyoD2. These changes were also corroborated by a significant decrease in proliferation and differentiation markers in the Lysine-deficient treatment. Moreover, both Lysine and Leucine limitation induced a significant down-regulation in FOXO3 gene expression, which deserves further investigation. We believe that these results will be relevant for the production of a species as appreciated for human consumption as it is gilthead sea bream and demonstrates the importance of an adequate level of Lysine in fishmeal diet formulation for optimum growth.
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Affiliation(s)
- Sheida Azizi
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Mohammad Ali Nematollahi
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran
- * E-mail: (MAN); (JG)
| | - Bagher Mojazi Amiri
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran
| | - Emilio J. Vélez
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Esmail Lutfi
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Isabel Navarro
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Encarnación Capilla
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Joaquim Gutiérrez
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
- * E-mail: (MAN); (JG)
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Leucine-induced anabolic-catabolism: two sides of the same coin. Amino Acids 2015; 48:321-36. [DOI: 10.1007/s00726-015-2109-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/28/2015] [Indexed: 10/22/2022]
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Fu L, Bruckbauer A, Li F, Cao Q, Cui X, Wu R, Shi H, Zemel MB, Xue B. Leucine amplifies the effects of metformin on insulin sensitivity and glycemic control in diet-induced obese mice. Metabolism 2015; 64:845-56. [PMID: 25858853 DOI: 10.1016/j.metabol.2015.03.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 03/11/2015] [Accepted: 03/13/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND OBJECTIVE The Sirt1/AMPK signaling pathway is a key sensor of energy status and regulates glucose and lipid metabolism. Leucine (Leu) activates Sirt1 by lowering its Km for NAD(+) and potentiates other sirtuin/AMPK-activators, resulting in improvement of insulin sensitivity. Since metformin (Met) converges on this pathway, we hypothesized that leucine would amplify its gluco-regulatory effects. MATERIALS AND METHODS The effects of Leu (24 g/kg diet)+Met (0.05-0.5 g/kg diet) combinations were compared to standard therapeutic Met (1.5 g/kg diet; ~300 mg/kg BW) on glycemic control in high fat diet induced insulin resistant mice for 6 weeks. The effects of Leu on Met stimulation of Sirt1 and AMPK activities were further evaluated in adipocytes. RESULTS Sub-therapeutic levels of Met combined with Leu resulted in increases in Sirt1 activity and in tissue P-AMPK/AMPK ratio and corresponding dose-responsive improvements in fasting and post-prandial glucose, in glucose response to an insulin tolerance test and in the area under the curve in glucose tolerance tests. Changes were evident within 7 days of treatment and sustained throughout the 6-week study duration. The Leu+Met (0.25 g/kg)-combinations produced a comparable effect to a standard therapeutic Met dose, while the Leu+Met (0.5 g/kg diet) resulted in greater improvements. Since resveratrol also synergizes with leucine to augment sirtuin signaling and insulin sensitivity, we tested the addition of resveratrol to Leu-Met and found no additional benefit. CONCLUSION These data demonstrate that adding Leu to Met enables a dose reduction of 66% with improved efficacy and of 83% with comparable efficacy to standard metformin in diet-induced obese mice, and addition of resveratrol does not provide further benefit.
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Affiliation(s)
- Lizhi Fu
- Center for Obesity Reversal, Department of Biology, Georgia State University, Atlanta, GA
| | | | - Fenfen Li
- Center for Obesity Reversal, Department of Biology, Georgia State University, Atlanta, GA
| | - Qiang Cao
- Center for Obesity Reversal, Department of Biology, Georgia State University, Atlanta, GA
| | - Xin Cui
- Center for Obesity Reversal, Department of Biology, Georgia State University, Atlanta, GA
| | - Rui Wu
- Center for Obesity Reversal, Department of Biology, Georgia State University, Atlanta, GA
| | - Hang Shi
- Center for Obesity Reversal, Department of Biology, Georgia State University, Atlanta, GA
| | | | - Bingzhong Xue
- Center for Obesity Reversal, Department of Biology, Georgia State University, Atlanta, GA.
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Mechanical stretch activates mammalian target of rapamycin and AMP-activated protein kinase pathways in skeletal muscle cells. Mol Cell Biochem 2015; 406:285-92. [PMID: 25971373 DOI: 10.1007/s11010-015-2446-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 05/07/2015] [Indexed: 10/23/2022]
Abstract
Cellular protein synthesis is believed to be antagonistically regulated by mammalian target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) signaling pathways. In the present study, we examined the relationship between mTOR/p70 S6 kinase (p70S6K) and AMPK in response to mechanical stretch. C2C12 myoblasts were grown on a silicone elastomer chamber to confluence and further cultured in differentiation medium for 4 days to form multinucleated myotubes. Cells were subjected to 15% cyclic uniaxial stretch for 4 h at a frequency of 1 Hz. Phosphorylation of p70S6K at threonine 389 and AMPK at threonine 172 of the catalytic α subunit were concomitantly increased by mechanical stretch. Stimulation of the mTOR pathway by adding leucine and insulin increased the phosphorylation of p70S6K without inactivation of AMPK. In contrast, addition of compound C, a pharmacological inhibitor of AMPK, increased the phosphorylation of p70S6K in stretched cells. Activation of AMPK by the addition of 5-amino-4-imidazolecarboxamide ribonucleoside reduced the phosphorylation of p70S6K in response to mechanical stretch. In conclusion, crosstalk between mTOR and AMPK signaling was not tightly regulated in response to physiological stimuli, such as mechanical stress and/or nutrients. However, pharmacological modulation of AMPK influenced the mTOR/p70S6K signaling pathway.
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Rahman H, Qasim M, Oellerich M, Asif AR. Crosstalk between Edc4 and mammalian target of rapamycin complex 1 (mTORC1) signaling in mRNA decapping. Int J Mol Sci 2014; 15:23179-95. [PMID: 25514416 PMCID: PMC4284759 DOI: 10.3390/ijms151223179] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 11/28/2014] [Accepted: 12/08/2014] [Indexed: 02/06/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) is involved in the cellular transcription and translation processes. The undertaken study characterized the enhancer of mRNA decapping protein 4 (Edc4) as mTORC1 interacting protein. Human T lymphoblast (CCRF-CEM) cells were used for mTORC1 purification. Co-immunoprecipitation coupled with immunoblotting analysis was used to confirm the interaction of Edc4 in mTORC1 specific purifications. Further assays were incorporated to conclude the role of mTORC1 in mRNA decapping via Edc4. Edc4 was identified as a new interacting protein with mTORC1 in both the endogenous and myc-tag raptor component mTORC1 specific purifications. Quantitative co-localization using confocal microscopy demonstrated that raptor component of mTORC1 coexists with Edc4 in processing (P) bodies, a site for mRNA degradation. Incubation of cells with rapamycin, a known inhibitor of mTOR kinase activity, increased the total Edc4 protein expression but at the same time decreased the Edc4 interaction with mTORC1. Moreover, rapamycin treatment resulted in a significant decrease in total serine phosphorylated Edc4 protein signal and the total 5'-capped mRNA. These findings provide the first evidence for the pivotal role of mTORC1 in Edc4 regulation. Further in-depth studies are required to get a complete understanding of molecular crosstalk between mTORC1 signaling and mRNA decapping pathway.
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Affiliation(s)
- Hazir Rahman
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Center, Robert-Koch-Str. 40, Goettingen 37075, Germany.
| | - Muhammad Qasim
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Center, Robert-Koch-Str. 40, Goettingen 37075, Germany.
| | - Michael Oellerich
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Center, Robert-Koch-Str. 40, Goettingen 37075, Germany.
| | - Abdul R Asif
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Center, Robert-Koch-Str. 40, Goettingen 37075, Germany.
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Areta JL, Hawley JA, Ye JM, Chan MS, Coffey VG. Increasing leucine concentration stimulates mechanistic target of rapamycin signaling and cell growth in C2C12 skeletal muscle cells. Nutr Res 2014; 34:1000-7. [DOI: 10.1016/j.nutres.2014.09.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 09/23/2014] [Accepted: 09/26/2014] [Indexed: 10/24/2022]
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Sato T, Ito Y, Nagasawa T. Lysine suppresses myofibrillar protein degradation by regulating the autophagic-lysosomal system through phosphorylation of Akt in C2C12 cells. SPRINGERPLUS 2014; 3:584. [PMID: 25332884 PMCID: PMC4197202 DOI: 10.1186/2193-1801-3-584] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 10/01/2014] [Indexed: 12/21/2022]
Abstract
The prevention of muscle wasting is important for maintaining quality of life, since loss of muscle mass can lead to a bedridden state and decreased resistance to diseases. The prevention of muscle wasting requires an increase in protein synthesis and a decrease in protein degradation in skeletal muscle. We previously showed that lysine (Lys) markedly suppressed myofibrillar protein degradation by inhibiting the autophagic-lysosomal system via the mammalian target of rapamycin (mTOR) and other signal molecules in C2C12 cells. In this study, we investigated the involvement of Akt and adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK), two regulators of autophagy, on the suppressive effects of Lys on myofibrillar protein degradation in C2C12 cells. Lys induced the phosphorylation of Akt, but the suppressive effects of Lys on myofibrillar protein degradation and autophagy were completely abolished in the presence of Akt1/2 kinase inhibitor (Akti). Lys suppressed the phosphorylation of AMPK, but this effect was also abolished by Akti. On the other hand, AMPK activation by 5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside (AICAR) did not affect either Akt activity or the autophagic-lysosomal system in C2C12 cells treated with Lys. These results indicate that regulation of AMPK activity is not essential for the regulation of autophagy by Lys. Taken together, our results show that Lys suppresses myofibrillar protein degradation by the autophagic-lysosomal system through the phosphorylation of Akt in C2C12 cells.
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Affiliation(s)
- Tomonori Sato
- Department of Bioresources Science, The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550 Japan
| | - Yoshiaki Ito
- Department of Biological Chemistry and Food Science, Graduate School of Agriculture, Iwate University, Morioka, Iwate 020-8550 Japan
| | - Takashi Nagasawa
- Department of Biological Chemistry and Food Science, Graduate School of Agriculture, Iwate University, Morioka, Iwate 020-8550 Japan
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Suryawan A, Nguyen HV, Almonaci RD, Davis TA. Differential regulation of protein synthesis in skeletal muscle and liver of neonatal pigs by leucine through an mTORC1-dependent pathway. J Anim Sci Biotechnol 2014; 3. [PMID: 22675606 PMCID: PMC3366465 DOI: 10.1186/2049-1891-3-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
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 eIF2α 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.
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Affiliation(s)
- Agus Suryawan
- Department of Pediatrics, Baylor College of Medicine, United States, Department of Agriculture/Agriculture Research Service Children's Nutrition Research Center, 1100 Bates Street, Houston, TX 77030, USA
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Boutry C, El-Kadi SW, Suryawan A, Wheatley SM, Orellana RA, Kimball SR, Nguyen HV, Davis TA. Leucine pulses enhance skeletal muscle protein synthesis during continuous feeding in neonatal pigs. Am J Physiol Endocrinol Metab 2013; 305:E620-31. [PMID: 23839523 PMCID: PMC3761169 DOI: 10.1152/ajpendo.00135.2013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Infants unable to maintain oral feeding can be nourished by orogastric tube. We have shown that orogastric continuous feeding restricts muscle protein synthesis compared with intermittent bolus feeding in neonatal pigs. To determine whether leucine infusion can be used to enhance protein synthesis during continuous feeding, neonatal piglets received the same amount of formula enterally by orogastric tube for 25.25 h continuously (CON) with or without LEU or intermittently by bolus every 4 h (BOL). For the CON+LEU group, leucine pulses were administered parenterally (800 μmol·kg(-1)·h(-1)) every 4 h. Insulin and glucose concentrations increased after the BOL meal and were unchanged in groups fed continuously. LEU infusion during CON feeding increased plasma leucine after the leucine pulse and decreased essential amino acids compared with CON feeding. Protein synthesis in longissimus dorsi (LD), gastrocnemius, and soleus muscles, but not liver or heart, were greater in CON+LEU and BOL than in the CON group. BOL feeding increased protein synthesis in the small intestine. Muscle S6K1 and 4E-BP1 phosphorylation and active eIF4E·eIF4G complex formation were higher in CON+LEU and BOL than in CON but AMPKα, eIF2α, and eEF2 phosphorylation were unchanged. LC3-II-to-total LC3 ratio was lower in CON+LEU and BOL than in CON, but there were no differences in atrogin-1 and MuRF-1 abundance and FoxO3 phosphorylation. In conclusion, administration of leucine pulses during continuous orogastric feeding in neonates increases muscle protein synthesis by stimulating translation initiation and may reduce protein degradation via the autophagy-lysosome, but not the ubiquitin-proteasome pathway.
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Affiliation(s)
- Claire Boutry
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston Texas; and
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Vaughan RA, Garcia-Smith R, Gannon NP, Bisoffi M, Trujillo KA, Conn CA. Leucine treatment enhances oxidative capacity through complete carbohydrate oxidation and increased mitochondrial density in skeletal muscle cells. Amino Acids 2013; 45:901-11. [PMID: 23812674 DOI: 10.1007/s00726-013-1538-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 06/17/2013] [Indexed: 12/30/2022]
Abstract
Leucine has been largely implicated for increasing muscle protein synthesis in addition to stimulating mitochondrial biosynthesis. Limited evidence is currently available on the effects and potential benefits of leucine treatment on skeletal muscle cell glycolytic and oxidative metabolism. This work identified the effects of leucine treatment on oxidative and glycolytic metabolism as well as metabolic rate of human and murine skeletal muscle cells. Human rhabdomyosarcoma cells (RD) and mouse myoblast cells (C2C12) were treated with leucine at either 100 or 500 μM for 24 or 48 h. Glycolytic metabolism was quantified by measuring extracellular acidification rate (ECAR) and oxidative metabolism was quantified by measuring oxygen consumption rate. Peroxisome proliferator-activated receptor coactivator 1 alpha (PGC-1α), an important stimulator of mitochondrial biosynthesis, was quantified using flow cytometry and verified by immunofluorescent confocal microscopy. Mitochondrial content was quantified using mitochondrial and cytochrome C staining measured by flow cytometry and confirmed with confocal microscopy. Treatment with leucine significantly increased both basal and peak oxidative metabolism in both cell models. Leucine treated cells also exhibited significantly greater mitochondrial proton leak, which is associated with heightened energy expenditure. Basal ECAR was significantly reduced in both cell models following leucine treatment, evidence of reduced lactate export and more complete carbohydrate oxidation. In addition, both PGC-1α and cytochrome C expression were significantly elevated in addition to mitochondrial content following 48 h of leucine treatment. Our observations demonstrated few dose-dependent responses induced by leucine; however, leucine treatment did induce a significant dose-dependent expression of PGC-1α in both cell models. Interestingly, C2C12 cells treated with leucine exhibited dose-dependently reduced ATP content, while RD ATP content remain unchanged. Leucine presents a potent dietary constituent with low lethality with numerous beneficial effects for increasing oxidative preference and capacity in skeletal muscle. Our observations demonstrate that leucine can enhance oxidative capacity and carbohydrate oxidation efficiency, as well as verify previous observations of increased mitochondrial content.
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Affiliation(s)
- Roger A Vaughan
- Department of Health, Exercise and Sports Science, University of New Mexico, 1 University Blvd, Albuquerque, NM, 87131, USA,
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Young JF, Therkildsen M, Ekstrand B, Che BN, Larsen MK, Oksbjerg N, Stagsted J. Novel aspects of health promoting compounds in meat. Meat Sci 2013; 95:904-11. [PMID: 23688796 DOI: 10.1016/j.meatsci.2013.04.036] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 04/11/2013] [Accepted: 04/12/2013] [Indexed: 02/06/2023]
Abstract
Meat is an integral part of the human diet. Besides essential amino acids and nutritive factors of high quality and availability, meat provides often overlooked components of importance for human health. These are amino acids and bioactive compounds that may be very important in i) preventing muscle wasting diseases, such as in sarcopenia, ii) reducing food and caloric intake to prevent metabolic syndrome, iii) blood pressure homeostasis via ACE-inhibitory components from connective tissue, and iv) maintaining functional gut environment through meat-derived nucleotides and nucleosides. In addition, meat could be an important source of phytanic acid, conjugated linoleic acids and antioxidants. Further, it becomes increasingly apparent that design of in vitro meat will be possible, and that this development may lead to improved health benefits from commercially viable and sustainable meat products.
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Affiliation(s)
- J F Young
- Department of Food Science, Aarhus University, Blichers Allé 20, Tjele, Denmark.
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48
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High early post-mortem temperature induces activation of AMP-activated protein kinase and development of pale, soft and exudative characteristics in turkey muscles. Meat Sci 2013; 93:600-6. [DOI: 10.1016/j.meatsci.2012.11.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 08/13/2012] [Accepted: 11/10/2012] [Indexed: 11/17/2022]
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49
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Pimentel GD, Ropelle ER, Rocha GZ, Carvalheira JBC. The role of neuronal AMPK as a mediator of nutritional regulation of food intake and energy homeostasis. Metabolism 2013; 62:171-8. [PMID: 22898253 DOI: 10.1016/j.metabol.2012.07.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 07/01/2012] [Accepted: 07/06/2012] [Indexed: 02/07/2023]
Abstract
Hypothalamic 5'-adenosine monophosphate-activated protein kinase (AMPK) senses intracellular metabolic stress, i.e., an increase in the cellular AMP:ATP ratio, and integrates diverse hormonal and nutritional signals to restore energy balance. Recent evidence suggests that different nutrients can modulate AMPK activity in the hypothalamus, thereby controlling weight gain through a leptin-independent mechanism. Understanding the mechanisms by which nutrients control hypothalamic AMPK activity is crucial to the development of effective nutritional interventions for the treatment of food intake-related disorders, such as anorexia and obesity. This article highlights the current evidence for the intricate relationship between nutrients and hypothalamic AMPK activity.
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Affiliation(s)
- Gustavo D Pimentel
- Department of Internal Medicine, State University of Campinas, Campinas/São Paulo, Brazil
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50
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Haegens A, Schols AM, van Essen AL, van Loon LJ, Langen RC. Leucine induces myofibrillar protein accretion in cultured skeletal muscle through mTOR dependent and -independent control of myosin heavy chain mRNA levels. Mol Nutr Food Res 2012; 56:741-52. [PMID: 22648621 DOI: 10.1002/mnfr.201100695] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
SCOPE Nutritional intervention during muscle wasting aims to attenuate net muscle protein loss. Branched chain amino acids, especially leucine, are able to stimulate the anabolic mammalian target of rapamycin (mTOR) signalling cascade and protein synthesis. It has been suggested that muscle myofibrillar protein expression is more responsive to amino acid supplementation compared to cytoplasmic proteins, although accretion of myofibrillar proteins has not extensively been investigated. We hypothesized that leucine specifically increases myofibrillar protein synthesis in skeletal muscle. METHODS AND RESULTS This hypothesis was investigated in C2C12 skeletal muscle cells using physiologically relevant culture conditions. Leucine supplementation specifically increased myofibrillar protein accretion, including myosin heavy chain-slow and -fast and myosin light chain 1 and -3 in C2C12 cells. Neither total protein content, nor de novo protein synthesis was affected, despite leucine-induced increased 4E-BP1 and S6K1 phosphorylation. Leucine supplementation did not affect myogenesis, measured by creatine kinase activity and myoblast fusion, either. Remarkably, leucine-induced increased myofibrillar protein accretion was accompanied by elevated MyHC mRNA levels, which involved mTOR-dependent and -independent regulation of MyHC-4 and MyHC-7 gene-expression, respectively. CONCLUSION This study clearly demonstrates myofibrillar and not generic protein accretion in skeletal muscle following leucine supplementation, and suggests this involves pre-translational control of MyHC expression by leucine.
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Affiliation(s)
- Astrid Haegens
- Top Institute Food & Nutrition-TIFN, Wageningen, The Netherlands.
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