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Tamura K, Kitazawa H, Sugita S, Hashizume K, Iwashita M, Ishigami T, Minegishi Y, Shimotoyodome A, Ota N. Tyrosine Is a Booster of Leucine-Induced Muscle Anabolic Response. Nutrients 2023; 16:84. [PMID: 38201913 PMCID: PMC10780460 DOI: 10.3390/nu16010084] [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: 11/16/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Leucine (Leu), an essential amino acid, is known to stimulate protein synthesis in the skeletal muscle via mTOR complex 1 (mTORC1) activation. However, the intrinsic contribution of other amino acids to Leu-mediated activation of mTORC1 signaling remains unexplored. This study aimed to identify amino acids that can promote mTORC1 activity in combination with Leu and to assess the effectiveness of these combinations in vitro and in vivo. We found that tyrosine (Tyr) enhanced Leu-induced phosphorylation of S6 kinase (S6K), an indicator of mTORC1 activity, although it exerted no such effect individually. This booster effect was observed in C2C12 cells, isolated murine muscle, and the skeletal muscles of mice orally administered the amino acids. To explore the molecular mechanisms underlying this Tyr-mediated booster effect, the expression of the intracellular Leu sensors, Sestrin1 and 2, was suppressed, and the cells were treated with Leu and Tyr. This suppression enabled Tyr alone to induce S6K phosphorylation and enhanced the booster effect, suggesting that Tyr possibly contributes to mTORC1 activation when Sestrin-GAP activity toward Rags 2 (GATOR2) is dissociated through Sestrin knockdown or the binding of Sestrins to Leu. Collectively, these results indicate that Tyr is a key regulator of Leu-mediated protein synthesis.
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Affiliation(s)
- Kotaro Tamura
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Hidefumi Kitazawa
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Satoshi Sugita
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Kohjiro Hashizume
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Masazumi Iwashita
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Takaaki Ishigami
- Processing Development Research, Kao Corporation, Wakayama-shi, Wakayama 640-8580, Japan
| | - Yoshihiko Minegishi
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Akira Shimotoyodome
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
| | - Noriyasu Ota
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan; (K.T.); (S.S.)
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2
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Hsu TH, Wu TJ, Tai YA, Huang CS, Liao JW, Yeh SL. The combination of quercetin and leucine synergistically improves grip strength by attenuating muscle atrophy by multiple mechanisms in mice exposed to cisplatin. PLoS One 2023; 18:e0291462. [PMID: 37699022 PMCID: PMC10497166 DOI: 10.1371/journal.pone.0291462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/25/2023] [Indexed: 09/14/2023] Open
Abstract
Both quercetin and leucine have been shown to exert moderately beneficial effects in preventing muscle atrophy induced by cancers or chemotherapy. However, the combined effects of quercetin and leucine, as well as the possible underlying mechanisms against cisplatin (CDDP)-induced muscle atrophy and cancer-related fatigue (CRF) remain unclear. To investigate the issues, male BALB/c mice were randomly assigned to the following groups for 9 weeks: Control, CDDP (3 mg/kg/week), CDDP+Q (quercetin 200 mg/kg/day administrated by gavage), CDDP+LL (a diet containing 0.8% leucine), CDDP+Q+LL, CDDP+HL (a diet containing 1.6% leucine), and CDDP+Q+HL. The results showed that quercetin in combination with LL or HL synergistically or additively attenuated CDDP-induced decreases in maximum grip strength, fat and muscle mass, muscle fiber size and MyHC level in muscle tissues. However, the combined effects on locomotor activity were less than additive. The combined treatments decreased the activation of the Akt/FoxO1/atrogin-1/MuRF1 signaling pathway (associated with muscle protein degradation), increased the activation of the mTOR and E2F-1 signaling pathways (associated with muscle protein synthesis and cell cycle/growth, respectively). The combined effects on signaling molecules present in muscle tissues were only additive or less. In addition, only Q+HL significantly increased glycogen levels compared to the CDDP group, while the combined treatments considerably decreased CDDP-induced proinflammatory cytokine and MCP-1 levels in the triceps muscle. Using tumor-bearing mice, we demonstrated that the combined treatments did not decrease the anticancer effect of CDDP. In conclusion, this study suggests that the combination of quercetin and leucine enhanced the suppressed effects on CDDP-induced muscle weakness and CRF through downregulating muscle atrophy and upregulating the glycogen level in muscle tissues without compromising the anticancer effect of CDDP. Multiple mechanisms, including regulation of several signaling pathways and decrease in proinflammatory mediator levels in muscles may contributed to the enhanced protective effect of the combined treatments on muscle atrophy.
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Affiliation(s)
- Te-Hsing Hsu
- Department of Nutritional Science, Chung Shan Medical University, Taichung, Taiwan
| | - Ting-Jian Wu
- Institute of medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Yu-An Tai
- Department of Nutritional Science, Chung Shan Medical University, Taichung, Taiwan
| | - Chin-Shiu Huang
- Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan
| | - Jiunn-Wang Liao
- Graduate Institute of Veterinary Pathology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Shu-Lan Yeh
- Department of Nutritional Science, Chung Shan Medical University, Taichung, Taiwan
- Department of Nutrition, Chung Shan Medical University Hospital, Taichung, Taiwan
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3
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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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Tedesco L, Rossi F, Ruocco C, Ragni M, Carruba MO, Valerio A, Nisoli E. A designer mixture of six amino acids promotes the extracellular matrix gene expression in cultured human fibroblasts. Biosci Biotechnol Biochem 2022; 86:1255-1261. [PMID: 35793559 DOI: 10.1093/bbb/zbac101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/20/2022] [Indexed: 11/14/2022]
Abstract
The deterioration of the skin is caused by dermatological disorders, environmental conditions, and ageing processes. One incisive strategy for supervising the skin ageing process is implementing healthy nutrition, preserving a balanced diet and a good supply of food supplements. Here, we compared H-Pro-Hyp-OH peptide, hydrolysed collagen, and an original mixture of six amino acids (we named 6aa)-including glycine, l-alanine, l-proline, l-valine, l-leucine, and l-lysine-effects on the production of extracellular matrix (ECM) components, particularly the elastin, fibronectin, collagen 1, and collagen 4. Treatment of BJ human skin fibroblasts with the 6aa mixture upregulated elastin, fibronectin, and collagen 1 gene expression, without affecting the expression of anti-reactive oxygen species enzymes. Moreover, the mTOR signaling pathway seems to be involved, at least in part. Collectively, these results suggest that the six amino acid mixture exerts beneficial effects in human skin fibroblasts.
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Affiliation(s)
- Laura Tedesco
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, via Vanvitelli, 32 - Milan, Italy
| | - Fabio Rossi
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, via Vanvitelli, 32 - Milan, Italy
| | - Chiara Ruocco
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, via Vanvitelli, 32 - Milan, Italy
| | - Maurizio Ragni
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, via Vanvitelli, 32 - Milan, Italy
| | - Michele O Carruba
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, via Vanvitelli, 32 - Milan, Italy
| | - Alessandra Valerio
- Department of Molecular and Translational Medicine, Brescia University, viale Europa, 11-25123 Brescia, Italy
| | - Enzo Nisoli
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, via Vanvitelli, 32 - Milan, Italy
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5
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Lv X, Zhou C, Yan Q, Tan Z, Kang J, Tang S. Elucidating the underlying mechanism of amino acids to regulate muscle protein synthesis: impact on human health. Nutrition 2022; 103-104:111797. [DOI: 10.1016/j.nut.2022.111797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 10/31/2022]
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6
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Wang N, Zhang X, Liu C, Wang X, Zhou H, Mai K, He G. Fine-Tuning of Postprandial Responses via Feeding Frequency and Leucine Supplementation Affects Dietary Performance in Turbot (Scophthalmus maximus L.). J Nutr 2021; 151:2957-2966. [PMID: 34255073 DOI: 10.1093/jn/nxab221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/22/2021] [Accepted: 06/15/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Feeding-induced cell signaling and metabolic responses affect utilization of dietary nutrients but are rarely taken advantage of to improve animal nutrition. OBJECTIVES We hypothesized that by modulating postprandial kinetics and signaling, improved dietary utilization and growth performance could be achieved in animals. METHODS Juvenile turbot (Scophthalmus maximus L.) with an initial mean ± SD weight of 10.1 ± 0.01 g were used. Two feeding frequencies (FFs), either 1 or 3 meals/d at a fixed 2.4% daily body weight ration, and 2 diets that were or were not supplemented with 1% crystalline leucine (Leu), were used in the 10-wk feeding trial. At the end of the trial, a 1-d force-feeding experiment was conducted using the aforementioned FF and experimental diets. Samples were collected for the analysis of postprandial kinetics of aminoacidemia, mechanistic target of rapamycin (mTOR) signaling activities, protein deposition, as well as the mRNA expression levels of key metabolic checkpoints at consecutive time points after feeding. RESULTS Increased FF and leucine supplementation significantly enhanced fish growth by 7.68% ± 0.53% (means ±SD) and 7.89% ± 1.25%, respectively, and protein retention by 4.01% ± 0.59% and 4.44% ± 1.63%, respectively, in feeding trial experiments. The durations of postprandial aminoacidemia and mTOR activation were extended by increased FF, whereas leucine supplementation enhanced mTOR signaling without influencing the postprandial free amino acids kinetics. Increased FF and leucine supplementation enhanced muscle protein deposition 21.6% ± 6.85% and 22.3% ± 1.52%, respectively, in a 24-h postfeeding period. CONCLUSIONS We provided comprehensive characterization of the postprandial kinetics of nutrient sensing and metabolic responses under different feeding regimens and leucine supplementation in turbot. Fine-tuning of postprandial kinetics could provide a new direction for better dietary utilization and animal performances in aquaculture.
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Affiliation(s)
- Ning Wang
- Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Xuemin Zhang
- Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Chengdong Liu
- Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Xuan Wang
- Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Huihui Zhou
- Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Kangsen Mai
- Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Gen He
- Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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7
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Allen SL, Marshall RN, Edwards SJ, Lord JM, Lavery GG, Breen L. The effect of young and old ex vivo human serum on cellular protein synthesis and growth in an in vitro model of aging. Am J Physiol Cell Physiol 2021; 321:C26-C37. [PMID: 33909501 DOI: 10.1152/ajpcell.00093.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In vitro models of muscle aging are useful for understanding mechanisms of age-related muscle loss and aiding the development of targeted therapies. To investigate mechanisms of age-related muscle loss in vitro utilizing ex vivo human serum, fasted blood samples were obtained from four old (72 ± 1 yr) and four young (26 ± 3 yr) men. Older individuals had elevated levels of plasma CRP, IL-6, HOMA-IR, and lower concentric peak torque and work-per-repetition compared with young participants (P < 0.05). C2C12 myotubes were serum and amino acid starved for 1 h and conditioned with human serum (10%) for 4 h or 24 h. After 4 h, C2C12 cells were treated with 5 mM leucine for 30 min. Muscle protein synthesis (MPS) was determined through the surface sensing of translation (SUnSET) technique and regulatory signaling pathways were measured via Western blot. Myotube diameter was significantly reduced in myotubes treated with serum from old, in comparison to young donors (84%, P < 0.001). MPS was reduced in myotubes treated with old donor serum, compared with young serum before leucine treatment (32%, P < 0.01). MPS and the phosphorylation of Akt, p70S6K, and eEF2 were increased in myotubes treated with young serum in response to leucine treatment, with a blunted response identified in cells treated with old serum (P < 0.05). Muscle protein breakdown signaling pathways did not differ between groups. In summary, we show that myotubes conditioned with serum from older individuals had decreased myotube diameter and MPS compared with younger individuals, potentially driven by low-grade systemic inflammation.
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Affiliation(s)
- Sophie L Allen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.,National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, United Kingdom
| | - Ryan N Marshall
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.,MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
| | - Sophie J Edwards
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Janet M Lord
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, United Kingdom.,MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom.,Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
| | - Gareth G Lavery
- National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, United Kingdom.,MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom.,Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partner, Birmingham, United Kingdom
| | - Leigh Breen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.,National Institute for Health Research, Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, United Kingdom.,MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom
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8
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Dadon-Freiberg M, Chapnik N, Froy O. REV-ERBα alters circadian rhythms by modulating mTOR signaling. Mol Cell Endocrinol 2021; 521:111108. [PMID: 33285244 DOI: 10.1016/j.mce.2020.111108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 11/22/2020] [Accepted: 11/30/2020] [Indexed: 11/21/2022]
Abstract
REV-ERBα is a nuclear receptor that inhibits Bmal1 transcription as part of the circadian clock molecular mechanism. Mammalian target of rapamycin (mTOR) complex 1 (mTORC1) is a master regulator of cell and whole-body energy homeostasis, that serves as an important link between metabolism and circadian clock, in part, by regulating BMAL1 activity. While the connection of REV-ERBα to the circadian clock molecular mechanism is well characterized, the interaction between mTORC1, REV-ERBα and the circadian clock machinery is not very clear. We used leucine and rapamycin to modulate mTORC1 activation and evaluate this effect on circadian rhythms. In the liver, mTORC1 was inhibited by leucine. REV-ERBα overexpression activated the mTORC1 signaling pathway via transcription inhibition of mTORC1 inhibitor, Tsc1, antagonizing the effect of leucine, while its silencing downregulated mTORC1 signaling. Activation of mTORC1 led to increased BMAL1 phosphorylation. Activation as well as inhibition of mTORC1 led to altered circadian rhythms in mouse muscle. Inhibition of liver mTORC1 by leucine or rapamycin led to low-amplitude circadian rhythms. In summary, our study shows that leucine inhibits liver mTORC1 pathway leading to dampened circadian rhythms. REV-ERBα activates the mTORC1 pathway, leading to phosphorylation of the clock protein BMAL1.
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Affiliation(s)
- Maayan Dadon-Freiberg
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Nava Chapnik
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Oren Froy
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
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9
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Zhao Y, Li JY, Jiang Q, Zhou XQ, Feng L, Liu Y, Jiang WD, Wu P, Zhou J, Zhao J, Jiang J. Leucine Improved Growth Performance, Muscle Growth, and Muscle Protein Deposition Through AKT/TOR and AKT/FOXO3a Signaling Pathways in Hybrid Catfish Pelteobagrus v achelli × Leiocassis longirostris. Cells 2020; 9:cells9020327. [PMID: 32019276 PMCID: PMC7072317 DOI: 10.3390/cells9020327] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 01/21/2020] [Accepted: 01/29/2020] [Indexed: 02/06/2023] Open
Abstract
(1) Background: l-leucine (Leu) plays a positive role in regulating protein turnover in skeletal muscle in mammal. However, the molecular mechanism for the effects of Leu on muscle growth and protein deposition is not clearly demonstrated in fish. This study investigated the effects of dietary Leu on growth performance and muscle growth, protein synthesis, and degradation-related signaling pathways of hybrid catfish (Pelteobagrus vachelli♀ × Leiocassis longirostris♂). (2) Methods: A total of 630 hybrid catfish (23.19 ± 0.20 g) were fed 6 different experimental diets containing graded levels of Leu at 10.0 (control), 15.0, 20.0, 25.0, 30.0, 35.0, and 40.0 g Leu kg-1 for 8 weeks. (3) Results: Results showed that dietary Leu increased percent weight gain (PWG), specific growth rate (SGR), FI (feed intake), feed efficiency (FE), protein efficiency ratio (PER), muscle fibers diameter, and muscle fibers density; up-regulated insulin-like growth factor I (IGF-I), insulin-like growth factor I receptor (IGF-IR), proliferating cell nuclear antigen (PCNA), myogenic regulation factors (MyoD, Myf5, MyoG, and Mrf4), and MyHC mRNA levels; increased muscle protein synthesis via regulating the AKT/TOR signaling pathway; and attenuated protein degradation via regulating the AKT/FOXO3a signaling pathway. (4) Conclusions: These results suggest that Leu has potential role to improve muscle growth and protein deposition in fish, which might be due to the regulation of IGF mRNA expression, muscle growth related gene, and protein synthesis and degradation-related signaling pathways. Based on the broken-line model, the Leu requirement of hybrid catfish (23.19-54.55 g) for PWG was estimated to be 28.10 g kg-1 of the diet (73.04 g kg-1 of dietary protein). These results will improve our understanding of the mechanisms responsible for muscle growth and protein deposition effects of Leu in fish.
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Affiliation(s)
- Ye Zhao
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Jin-Yang Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Qin Jiang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiao-Qiu Zhou
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
- Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Lin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
- Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Yang Liu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
- Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Wei-Dan Jiang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
- Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Pei Wu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
- Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Jian Zhou
- Fisheries Institute of Sichuan Academy of Agricultural Science, Chengdu 611731, China
| | - Juan Zhao
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Jun Jiang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
- Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
- Correspondence: ; Tel.: +86-28-8629-1133
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10
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Duan Y, Zhong Y, Song B, Zheng C, Xu K, Kong X, Li F. Suppression of protein degradation by leucine requires its conversion to β-hydroxy-β-methyl butyrate in C2C12 myotubes. Aging (Albany NY) 2019; 11:11922-11936. [PMID: 31881014 PMCID: PMC6949090 DOI: 10.18632/aging.102509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 11/18/2019] [Indexed: 05/05/2023]
Abstract
The aims of this study were to investigate whether the inhibitory effect of Leucine (Leu) on starvation-induced protein degradation was mediated by its metabolite β-hydroxy-β-methyl butyrate (HMB), and to explore the mechanisms involved. The results showed that the beneficial effects of Leu on protein degradation and the oxygen consumption rate (OCR) of cells were observed at low levels (0.5 mM) rather than at high levels (10 mM). However, these effects were inferior to those of HMB. Moreover, HMB was able to increase/decrease the proportion of MyHC I/MyHC IIb protein expression, respectively. In these KICD-transfected cells, Leu was approximately as effective as HMB in inhibiting protein degradation and increasing the OCR as well as MyHC I protein expression of cells, and these effects of Leu were reverted to a normal state by mesotrione, a specific suppressor of KICD. In conclusion, HMB seems to be an active metabolite of Leu to suppress muscle protein degradation in a starvation model, and the mechanisms may be associated with improved mitochondrial oxidative capacity in muscle cells.
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Affiliation(s)
- Yehui Duan
- Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, P. R. China
| | - Yinzhao Zhong
- Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, P. R. China
| | - Bo Song
- Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, P. R. China
| | - Changbing Zheng
- Guangdong Provincial Key Laboratory of Animal Nutrition Regulation, South China Agricultural University, Guangzhou, Guangdong, China
| | - Kang Xu
- Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, P. R. China
| | - Xiangfeng Kong
- Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, P. R. China
| | - Fengna Li
- Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, P. R. China
- Hunan Co-Innovation Center of Animal Production Safety, CICAPS, Hunan Collaborative Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, Hunan, China
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11
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The Effects of Leucine-Enriched Branched-Chain Amino Acid Supplementation on Recovery After High-Intensity Resistance Exercise. Int J Sports Physiol Perform 2019; 14:1081-1088. [DOI: 10.1123/ijspp.2018-0579] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/16/2018] [Accepted: 01/08/2019] [Indexed: 11/18/2022]
Abstract
Context: Of the 3 branched-chain amino acids (BCAA), leucine has arguably received the most attribution for the role of BCAA supplementation in alleviating symptoms of exercise-induced muscle damage and facilitation of acute performance recovery. Purpose: To examine whether enrichment of a standard BCAA supplement with additional leucine or a standalone leucine (LEU) supplement differentially affects exercise-induced muscle damage and performance recovery compared with a standard BCAA supplement. Methods: A total of 22 recreationally active male and female subjects were recruited and assigned to consume a BCAA, leucine-enriched BCAA (LBCAA), or LEU supplement for 11 d. On the eighth day, subjects performed eccentric-based resistance exercise (ECRE). Lower-body mean average and peak power, plasma creatine kinase, soreness, and pain threshold were measured before and 24, 48, and 72 h after ECRE. Results: LEU showed decreased mean average power (P = .02) and mean peak power (P = .01) from baseline to 48 h post-ECRE, whereas LBCAA and BCAA only trended toward a reduction at 24 hours post-ECRE. At 48 h post-ECRE, BCAA showed greater recovery of mean peak power than LEU (P = .04). At 24 h post-ECRE, LEU demonstrated a greater increase in plasma creatine kinase from baseline than BCAA (P = .04). Area under the curve for creatine kinase was greater in LEU than BCAA (P = .02), whereas BCAA and LBCAA did not differ. Only LEU demonstrated increased soreness during rest and under muscular tension at 24 and 48 h post-ECRE (P < .05). Conclusions: LBCAA failed to afford any advantages over a standard BCAA supplement for postexercise muscle recovery, whereas a LEU supplement was comparatively ineffective.
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12
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Duan Y, Li F, Song B, Zheng C, Zhong Y, Xu K, Kong X, Yin Y, Wang W, Shu G. β-hydroxy-β-methyl butyrate, but not α-ketoisocaproate and excess leucine, stimulates skeletal muscle protein metabolism in growing pigs fed low-protein diets. J Funct Foods 2019. [DOI: 10.1016/j.jff.2018.10.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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13
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Kwak SE, Lee JH, Zhang D, Song W. Angiogenesis: focusing on the effects of exercise in aging and cancer. J Exerc Nutrition Biochem 2018; 22:21-26. [PMID: 30343555 PMCID: PMC6199487 DOI: 10.20463/jenb.2018.0020] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/18/2018] [Indexed: 01/05/2023] Open
Abstract
[Purpose] Although it is known that exercise induces angiogenesis, a clear mechanism has remained elusive due to various experimental limitations. This review presents the current status of angiogenesis-related experiments and future directions of experimentation in relation to exercise, aging, and cancer. [Methods] We conducted a PubMed search of the available literature to identify reported exercise related changes of angiogenic factors obtained in vitro using C2C12 cells and endothelial cells, and in vivo using animal experiments and in clinical studies. [Results] Exercise induced angiogenesis under normal conditions. Aging decreased angiogenic factors and increased during exercise. On the other hand, in cancer, the results indicate that angiogenic factors tend to increase in general, and that the effects of exercise need to be studied more. The exact mechanism remains unclear. [Conclusion] The effect of exercise on angiogenesis appears positive. Both resistance and aerobic exercise have positive effects, but many evidences suggest that the effects are more pronounced with aerobic exercise. Further research on the precise mechanism(s) is necessary. It is expected that these studies will include models of aging and cancer.
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14
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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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15
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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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16
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Brown AD, Close GL, Sharples AP, Stewart CE. Murine myoblast migration: influence of replicative ageing and nutrition. Biogerontology 2017; 18:947-964. [PMID: 29110174 PMCID: PMC5684311 DOI: 10.1007/s10522-017-9735-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/28/2017] [Indexed: 02/08/2023]
Abstract
Cell migration is central to skeletal muscle repair following damage. Leucine and β-Hydroxy β-methylbutyric acid (HMB) are supplements consumed for recovery from muscle damaging exercise in humans, however, their impact on muscle cell migration with age is not yet understood. We hypothesised that replicatively aged ("aged"; P46-P48) myoblasts would be less efficient at basal and supplemented repair versus parental controls ("control"; P12-P16). Aged and control myoblasts were scratch-damaged and migration velocity, directionality and distance assessed over 48 h in the absence and presence of leucine (10 mM) or HMB (10 mM) ± PI3K/Akt (LY294002 10 μM), ERK (PD98059 5 μM) or mTOR (rapamycin 0.5 μM) inhibition. Opposing our hypothesis, aged cells displayed increased velocities, directionality and distance migrated (P < 0.001) versus control. Leucine and HMB significantly increased (P < 0.001) the same parameters in control cells. The supplements were with smaller, albeit significant impact on aged cell velocity (P < 0.001) and in the presence of HMB only, distance (P = 0.041). Inhibitor studies revealed that, PI3K and ERK activation were essential for velocity, directionality and migration distance of aged cells in basal conditions, whereas mTOR was important for directionality only. While PI3K activation was critical for all parameters in control cells (P < 0.001), inhibition of ERK or mTOR improved, rather than reduced, control cell migration distance. Enhanced basal velocity, directionality and distance in aged cells required ERK and PI3K activation. By contrast, in control cells, basal migration was underpinned by PI3K activation, and facilitated by leucine or HMB supplementation, to migration levels seen in aged cells. These data suggest that replicatively aged myoblasts are not anabolically resistant per se, but are capable of efficient repair, underpinned by altered signaling pathways, compared with unaged control myoblasts.
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Affiliation(s)
- Alexander D Brown
- Stem Cells, Ageing & Molecular Physiology Unit, Research Institute for Sport and Exercise Sciences (RISES), School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.
| | - Graeme L Close
- Stem Cells, Ageing & Molecular Physiology Unit, Research Institute for Sport and Exercise Sciences (RISES), School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Adam P Sharples
- Stem Cells, Ageing & Molecular Physiology Unit, Research Institute for Sport and Exercise Sciences (RISES), School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Claire E Stewart
- Stem Cells, Ageing & Molecular Physiology Unit, Research Institute for Sport and Exercise Sciences (RISES), School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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17
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Li SS, Loor JJ, Liu HY, Liu L, Hosseini A, Zhao WS, Liu JX. Optimal ratios of essential amino acids stimulate β-casein synthesis via activation of the mammalian target of rapamycin signaling pathway in MAC-T cells and bovine mammary tissue explants. J Dairy Sci 2017; 100:6676-6688. [PMID: 28571990 DOI: 10.3168/jds.2017-12681] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/17/2017] [Indexed: 12/26/2022]
Abstract
Amino acids are the building blocks of proteins and serve as key molecular components upstream of the signaling pathways that regulate protein synthesis. The objective of this study was to systematically investigate the effect of essential AA ratios on milk protein synthesis in vitro and to elucidate some of the underlying mechanisms. Triplicate cultures of MAC-T cells and bovine mammary tissue explants (MTE) were incubated with the optimal AA ratio (OPAA; Lys:Met, 2.9:1; Thr:Phe, 1.05:1; Lys:Thr, 1.8:1; Lys:His, 2.38:1; and Lys:Val, 1.23:1) in the presence of rapamycin (control), OPAA, a Lys:Thr ratio of 2.1:1, a Lys:Thr ratio of 1.3:1, a Lys:His ratio of 3.05:1, or a Lys:Val ratio of 1.62:1 for 12 h; the other AA concentrations were equal to OPAA. In some experiments, the cells were cultured with OPAA with or without rapamycin (100 ng/mL) or with mammalian target of rapamycin (mTOR) small interference RNA, and the MTE were exposed to OPAA with rapamycin for β-casein expression. Among the treatments, the expression of β-casein was greatest in the MTE cultured with OPAA. In MAC-T cells, the OPAA upregulated the mRNA expression of SLC1A5 and SLC7A5 but downregulated the expression of IRS1, AKT3, EEF1A1, and EEF2 compared with the control. The OPAA had no effect on the mTOR phosphorylation status but increased the phosphorylation of S6K1 and RPS6. When the MTE were treated with rapamycin in the presence of OPAA, the expression of β-casein was markedly decreased. The phosphorylation of RPS6 and 4EBP1 also was reduced in MAC-T cells. A similar negative effect on the expression of RPS6KB1 and EIF4EBP1 was detected when the cells were cultured with either rapamycin or mTOR small interference RNA. The optimal AA ratio stimulated β-casein expression partly by enhancing the transport of AA into the cells, cross-talk with insulin signaling and a subsequent enhancement of mTOR signaling, or translation elongation in both MAC-T cells and bovine MTE.
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Affiliation(s)
- S S Li
- Institute of Dairy Science, College of Animal Sciences, MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou 310058, P. R. China
| | - J J Loor
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801.
| | - H Y Liu
- Institute of Dairy Science, College of Animal Sciences, MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou 310058, P. R. China
| | - L Liu
- Institute of Dairy Science, College of Animal Sciences, MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou 310058, P. R. China
| | - A Hosseini
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801
| | - W S Zhao
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801
| | - J X Liu
- Institute of Dairy Science, College of Animal Sciences, MoE Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou 310058, P. R. China.
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18
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Martin NRW, Turner MC, Farrington R, Player DJ, Lewis MP. Leucine elicits myotube hypertrophy and enhances maximal contractile force in tissue engineered skeletal muscle in vitro. J Cell Physiol 2017; 232:2788-2797. [PMID: 28409828 PMCID: PMC5518187 DOI: 10.1002/jcp.25960] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 04/13/2017] [Indexed: 01/07/2023]
Abstract
The amino acid leucine is thought to be important for skeletal muscle growth by virtue of its ability to acutely activate mTORC1 and enhance muscle protein synthesis, yet little data exist regarding its impact on skeletal muscle size and its ability to produce force. We utilized a tissue engineering approach in order to test whether supplementing culture medium with leucine could enhance mTORC1 signaling, myotube growth, and muscle function. Phosphorylation of the mTORC1 target proteins 4EBP-1 and rpS6 and myotube hypertrophy appeared to occur in a dose dependent manner, with 5 and 20 mM of leucine inducing similar effects, which were greater than those seen with 1 mM. Maximal contractile force was also elevated with leucine supplementation; however, although this did not appear to be enhanced with increasing leucine doses, this effect was completely ablated by co-incubation with the mTOR inhibitor rapamycin, showing that the augmented force production in the presence of leucine was mTOR sensitive. Finally, by using electrical stimulation to induce chronic (24 hr) contraction of engineered skeletal muscle constructs, we were able to show that the effects of leucine and muscle contraction are additive, since the two stimuli had cumulative effects on maximal contractile force production. These results extend our current knowledge of the efficacy of leucine as an anabolic nutritional aid showing for the first time that leucine supplementation may augment skeletal muscle functional capacity, and furthermore validates the use of engineered skeletal muscle for highly-controlled investigations into nutritional regulation of muscle physiology.
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Affiliation(s)
- Neil R W Martin
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Mark C Turner
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Robert Farrington
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Darren J Player
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Mark P Lewis
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
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19
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Le Plénier S, Goron A, Sotiropoulos A, Archambault E, Guihenneuc C, Walrand S, Salles J, Jourdan M, Neveux N, Cynober L, Moinard C. Citrulline directly modulates muscle protein synthesis via the PI3K/MAPK/4E-BP1 pathway in a malnourished state: evidence from in vivo, ex vivo, and in vitro studies. Am J Physiol Endocrinol Metab 2017; 312:E27-E36. [PMID: 27827806 DOI: 10.1152/ajpendo.00203.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 10/13/2016] [Accepted: 10/18/2016] [Indexed: 12/16/2022]
Abstract
Citrulline (CIT) is an endogenous amino acid produced by the intestine. Recent literature has consistently shown CIT to be an activator of muscle protein synthesis (MPS). However, the underlying mechanism is still unknown. Our working hypothesis was that CIT might regulate muscle homeostasis directly through the mTORC1/PI3K/MAPK pathways. Because CIT undergoes both interorgan and intraorgan trafficking and metabolism, we combined three approaches: in vivo, ex vivo, and in vitro. Using a model of malnourished aged rats, CIT supplementation activated the phosphorylation of S6K1 and 4E-BP1 in muscle. Interestingly, the increase in S6K1 phosphorylation was positively correlated (P < 0.05) with plasma CIT concentration. In a model of isolated incubated skeletal muscle from malnourished rats, CIT enhanced MPS (from 30 to 80% CIT vs. Ctrl, P < 0.05), and the CIT effect was abolished in the presence of wortmannin, rapamycin, and PD-98059. In vitro, on myotubes in culture, CIT led to a 2.5-fold increase in S6K1 phosphorylation and a 1.5-fold increase in 4E-BP1 phosphorylation. Both rapamycin and PD-98059 inhibited the CIT effect on S6K1, whereas only LY-294002 inhibited the CIT effect on both S6K1 and 4E-BP1. These findings show that CIT is a signaling agent for muscle homeostasis, suggesting a new role of the intestine in muscle mass control.
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Affiliation(s)
- Servane Le Plénier
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France;
| | - Arthur Goron
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Athanassia Sotiropoulos
- Centre National de la Recherche Scientifique UMR 8104, Institut Cochin, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Eliane Archambault
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Chantal Guihenneuc
- Laboratoire d'épidémiologie environnementale, EA 4064, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Stéphane Walrand
- Unité de Nutrition humaine, UMR 1019, Institut National de la Recherche Agronomique/Université d'Auvergne, Centre de Recherche en Nutrition Humaine, Auvergne, Clermont-Ferrand, France; and
| | - Jérome Salles
- Unité de Nutrition humaine, UMR 1019, Institut National de la Recherche Agronomique/Université d'Auvergne, Centre de Recherche en Nutrition Humaine, Auvergne, Clermont-Ferrand, France; and
| | - Marion Jourdan
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Nathalie Neveux
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Luc Cynober
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
- Service de Biochimie interhospitalier Cochin et Hôtel-Dieu, GH Hôpitaux universitaire Paris Centre, AP-HP, Paris, France
| | - Christophe Moinard
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
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20
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Zhang Y, Yu B, He J, Chen D. From Nutrient to MicroRNA: a Novel Insight into Cell Signaling Involved in Skeletal Muscle Development and Disease. Int J Biol Sci 2016; 12:1247-1261. [PMID: 27766039 PMCID: PMC5069446 DOI: 10.7150/ijbs.16463] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/19/2016] [Indexed: 12/17/2022] Open
Abstract
Skeletal muscle is a remarkably complicated organ comprising many different cell types, and it plays an important role in lifelong metabolic health. Nutrients, as an external regulator, potently regulate skeletal muscle development through various internal regulatory factors, such as mammalian target of rapamycin (mTOR) and microRNAs (miRNAs). As a nutrient sensor, mTOR, integrates nutrient availability to regulate myogenesis and directly or indirectly influences microRNA expression. MiRNAs, a class of small non-coding RNAs mediating gene silencing, are implicated in myogenesis and muscle-related diseases. Meanwhile, growing evidence has emerged supporting the notion that the expression of myogenic miRNAs could be regulated by nutrients in an epigenetic mechanism. Therefore, this review presents a novel insight into the cell signaling network underlying nutrient-mTOR-miRNA pathway regulation of skeletal myogenesis and summarizes the epigenetic modifications in myogenic differentiation, which will provide valuable information for potential therapeutic intervention.
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Affiliation(s)
- Yong Zhang
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya'an, Sichuan 625014, P. R. China.; Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, China
| | - Bing Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya'an, Sichuan 625014, P. R. China.; Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, China
| | - Jun He
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya'an, Sichuan 625014, P. R. China.; Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, China
| | - Daiwen Chen
- Institute of Animal Nutrition, Sichuan Agricultural University, Ya'an, Sichuan 625014, P. R. China.; Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, China
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21
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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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22
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Cai X, Zhu C, Xu Y, Jing Y, Yuan Y, Wang L, Wang S, Zhu X, Gao P, Zhang Y, Jiang Q, Shu G. Alpha-ketoglutarate promotes skeletal muscle hypertrophy and protein synthesis through Akt/mTOR signaling pathways. Sci Rep 2016; 6:26802. [PMID: 27225984 PMCID: PMC4881026 DOI: 10.1038/srep26802] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 05/10/2016] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle weight loss is accompanied by small fiber size and low protein content. Alpha-ketoglutarate (AKG) participates in protein and nitrogen metabolism. The effect of AKG on skeletal muscle hypertrophy has not yet been tested, and its underlying mechanism is yet to be determined. In this study, we demonstrated that AKG (2%) increased the gastrocnemius muscle weight and fiber diameter in mice. Our in vitro study also confirmed that AKG dose increased protein synthesis in C2C12 myotubes, which could be effectively blocked by the antagonists of Akt and mTOR. The effects of AKG on skeletal muscle protein synthesis were independent of glutamate, its metabolite. We tested the expression of GPR91 and GPR99. The result demonstrated that C2C12 cells expressed GPR91, which could be upregulated by AKG. GPR91 knockdown abolished the effect of AKG on protein synthesis but failed to inhibit protein degradation. These findings demonstrated that AKG promoted skeletal muscle hypertrophy via Akt/mTOR signaling pathway. In addition, GPR91 might be partially attributed to AKG-induced skeletal muscle protein synthesis.
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MESH Headings
- Animals
- Cell Line
- Gene Knockdown Techniques
- Glutamic Acid/metabolism
- Glutamic Acid/pharmacology
- Hypertrophy/chemically induced
- Hypertrophy/metabolism
- Ketoglutaric Acids/pharmacology
- Ketoglutaric Acids/toxicity
- Mice, Inbred C57BL
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/ultrastructure
- Muscle Proteins/biosynthesis
- Muscle Proteins/genetics
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Phosphorylation
- Protein Processing, Post-Translational
- Proto-Oncogene Proteins c-akt/physiology
- RNA Interference
- RNA, Small Interfering/genetics
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/biosynthesis
- Receptors, G-Protein-Coupled/genetics
- Receptors, Purinergic P2/biosynthesis
- Receptors, Purinergic P2/genetics
- Signal Transduction/drug effects
- TOR Serine-Threonine Kinases/physiology
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Affiliation(s)
- Xingcai Cai
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Canjun Zhu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Yaqiong Xu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Yuanyuan Jing
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Yexian Yuan
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Lina Wang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Songbo Wang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Xiaotong Zhu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Ping Gao
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Yongliang Zhang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Qingyan Jiang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
- ALLTECH-SCAU Animal Nutrition Control Research Alliance, South China Agricultural University, Guangzhou 510642, PR China
| | - Gang Shu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, 510642, China
- ALLTECH-SCAU Animal Nutrition Control Research Alliance, South China Agricultural University, Guangzhou 510642, PR China
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23
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Yin B, Li T, Zhang S, Li Z, He P. Sensitive Analysis of 33 Free Amino Acids in Serum, Milk, and Muscle by Ultra-High Performance Liquid Chromatography-Quadrupole-Orbitrap High Resolution Mass Spectrometry. FOOD ANAL METHOD 2016. [DOI: 10.1007/s12161-016-0463-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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24
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Girón MD, Vílchez JD, Salto R, Manzano M, Sevillano N, Campos N, Argilés JM, Rueda R, López-Pedrosa JM. Conversion of leucine to β-hydroxy-β-methylbutyrate by α-keto isocaproate dioxygenase is required for a potent stimulation of protein synthesis in L6 rat myotubes. J Cachexia Sarcopenia Muscle 2016; 7:68-78. [PMID: 27065075 PMCID: PMC4799859 DOI: 10.1002/jcsm.12032] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 03/03/2015] [Accepted: 03/10/2015] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND L-Leu and its metabolite β-hydroxy-β-methylbutyrate (HMB) stimulate muscle protein synthesis enhancing the phosphorylation of proteins that regulate anabolic signalling pathways. Alterations in these pathways are observed in many catabolic diseases, and HMB and L-Leu have proven their anabolic effects in in vivo and in vitro models. The aim of this study was to compare the anabolic effects of L-Leu and HMB in myotubes grown in the absence of any catabolic stimuli. METHODS Studies were conducted in vitro using rat L6 myotubes under normal growth conditions (non-involving L-Leu-deprived conditions). Protein synthesis and mechanistic target of rapamycin signalling pathway were determined. RESULTS Only HMB was able to increase protein synthesis through a mechanism that involves the phosphorylation of the mechanistic target of rapamycin as well as its downstream elements, pS6 kinase, 4E binding protein-1, and eIF4E. HMB was significantly more effective than L-Leu in promoting these effects through an activation of protein kinase B/Akt. Because the conversion of L-Leu to HMB is limited in muscle, L6 cells were transfected with a plasmid that codes for α-keto isocaproate dioxygenase, the key enzyme involved in the catabolic conversion of α-keto isocaproate into HMB. In these transfected cells, L-Leu was able to promote protein synthesis and mechanistic target of rapamycin regulated pathway activation equally to HMB. Additionally, these effects of leucine were reverted to a normal state by mesotrione, a specific inhibitor of α-keto isocaproate dioxygenase. CONCLUSION Our results suggest that HMB is an active L-Leu metabolite able to maximize protein synthesis in skeletal muscle under conditions, in which no amino acid deprivation occurred. It may be proposed that supplementation with HMB may be very useful to stimulate protein synthesis in wasting conditions associated with chronic diseases, such as cancer or chronic heart failure.
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Affiliation(s)
- María D Girón
- Department of Biochemistry and Molecular Biology II School of Pharmacy, University of Granada Granada Spain
| | - José D Vílchez
- Department of Biochemistry and Molecular Biology II School of Pharmacy, University of Granada Granada Spain
| | - Rafael Salto
- Department of Biochemistry and Molecular Biology II School of Pharmacy, University of Granada Granada Spain
| | | | - Natalia Sevillano
- Department of Biochemistry and Molecular Biology II School of Pharmacy, University of Granada Granada Spain
| | | | - Josep M Argilés
- Cancer Research Group, Department de Bioquimica I Biologia Molecular Facultat de Biologia, Universitat de Barcelona Barcelona Spain
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25
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Lee DE, Brown JL, Rosa ME, Brown LA, Perry RA, Wiggs MP, Nilsson MI, Crouse SF, Fluckey JD, Washington TA, Greene NP. microRNA-16 Is Downregulated During Insulin Resistance and Controls Skeletal Muscle Protein Accretion. J Cell Biochem 2016; 117:1775-87. [DOI: 10.1002/jcb.25476] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/17/2015] [Indexed: 12/28/2022]
Affiliation(s)
- David E. Lee
- Integrative Muscle Metabolism Laboratory; Human Performance Laboratory; Department of Health; Human Performance and Recreation; University of Arkansas; Fayetteville Arkansas 72701
| | - Jacob L. Brown
- Integrative Muscle Metabolism Laboratory; Human Performance Laboratory; Department of Health; Human Performance and Recreation; University of Arkansas; Fayetteville Arkansas 72701
| | - Megan E. Rosa
- Integrative Muscle Metabolism Laboratory; Human Performance Laboratory; Department of Health; Human Performance and Recreation; University of Arkansas; Fayetteville Arkansas 72701
| | - Lemuel A. Brown
- Exercise Muscle Biology Laboratory; Human Performance Laboratory; Department of Health; Human Performance and Recreation; University of Arkansas; Fayetteville Arkansas 72701
| | - Richard A. Perry
- Exercise Muscle Biology Laboratory; Human Performance Laboratory; Department of Health; Human Performance and Recreation; University of Arkansas; Fayetteville Arkansas 72701
| | - Michael P. Wiggs
- Muscle Biology Laboratory; Department of Health and Kinesiology; Texas A&M University; College Station Texas 77843
| | - Mats I. Nilsson
- Muscle Biology Laboratory; Department of Health and Kinesiology; Texas A&M University; College Station Texas 77843
| | - Stephen F. Crouse
- Applied Exercise Science Laboratory; Department of Health and Kinesiology; Texas A&M University; College Station Texas 77843
| | - James D. Fluckey
- Muscle Biology Laboratory; Department of Health and Kinesiology; Texas A&M University; College Station Texas 77843
| | - Tyrone A. Washington
- Exercise Muscle Biology Laboratory; Human Performance Laboratory; Department of Health; Human Performance and Recreation; University of Arkansas; Fayetteville Arkansas 72701
| | - Nicholas P. Greene
- Integrative Muscle Metabolism Laboratory; Human Performance Laboratory; Department of Health; Human Performance and Recreation; University of Arkansas; Fayetteville Arkansas 72701
- Muscle Biology Laboratory; Department of Health and Kinesiology; Texas A&M University; College Station Texas 77843
- Applied Exercise Science Laboratory; Department of Health and Kinesiology; Texas A&M University; College Station Texas 77843
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26
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Zou X, Meng J, Li L, Han W, Li C, Zhong R, Miao X, Cai J, Zhang Y, Zhu D. Acetoacetate Accelerates Muscle Regeneration and Ameliorates Muscular Dystrophy in Mice. J Biol Chem 2015; 291:2181-95. [PMID: 26645687 DOI: 10.1074/jbc.m115.676510] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Indexed: 11/06/2022] Open
Abstract
Acetoacetate (AA) is a ketone body and acts as a fuel to supply energy for cellular activity of various tissues. Here, we uncovered a novel function of AA in promoting muscle cell proliferation. Notably, the functional role of AA in regulating muscle cell function is further evidenced by its capability to accelerate muscle regeneration in normal mice, and it ameliorates muscular dystrophy in mdx mice. Mechanistically, our data from multiparameter analyses consistently support the notion that AA plays a non-metabolic role in regulating muscle cell function. Finally, we show that AA exerts its function through activation of the MEK1-ERK1/2-cyclin D1 pathway, revealing a novel mechanism in which AA serves as a signaling metabolite in mediating muscle cell function. Our findings highlight the profound functions of a small metabolite as signaling molecule in mammalian cells.
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Affiliation(s)
- Xiaoting Zou
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Jiao Meng
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Li Li
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Wanhong Han
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Changyin Li
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Ran Zhong
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Xuexia Miao
- the Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jun Cai
- the Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yong Zhang
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Dahai Zhu
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
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27
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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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28
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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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