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Sakamoto T, Ueda SY, Nakahara H. Effects of Short-Term Nighttime Carbohydrate Restriction Method on Exercise Performance and Fat Metabolism. Nutrients 2024; 16:2138. [PMID: 38999884 PMCID: PMC11243291 DOI: 10.3390/nu16132138] [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: 05/26/2024] [Revised: 06/25/2024] [Accepted: 06/26/2024] [Indexed: 07/14/2024] Open
Abstract
BACKGROUND The sleep-low method has been proposed as a way to sleep in a low-glycogen state, increase the duration of low glycogen availability and sleep and temporarily restrict carbohydrates to improve exercise performance. However, long-term dietary restriction may induce mental stress in athletes. Therefore, if it can be shown that the effects of the sleep-low method can be achieved by restricting the carbohydrate intake at night (the nighttime carbohydrate restriction method), innovative methods could be developed to reduce weight in individuals with obesity and enhance athletes' performance with reduced stress and in a shorter duration when compared with those of previous studies. With this background, we conducted a study with the purpose of examining the intervention effects of a short-term intensive nighttime carbohydrate restriction method. METHODS A total of 22 participants were recruited among university students participating in sports club activities. The participants were assigned at random to groups, including a nighttime carbohydrate restriction group of 11 participants (6 males, 5 females; age 22.3 ± 1.23) who started a carbohydrate-restricted diet and a group of 11 participants (5 males, 6 females; age 21.9 ± 7.9) who continued with their usual diet. The present study had a two-group parallel design. In the first week, no dietary restrictions were imposed on either group, and the participants consumed their own habitual diets. In the second week, the total amount of calories and carbohydrate intake measured in the first week were divided by seven days, and the average values were calculated. These were used as the daily calorie and carbohydrate intakes in the second week. Only the nighttime carbohydrate restriction group was prohibited from consuming carbohydrates after 4:00 p.m. During the two-week study period, all participants ran for one hour each day before breakfast at a heart rate of 65% of their maximum heart rate. RESULTS The results obtained from young adults participating in sports showed significant differences in peak oxygen consumption (V·O2peak), work rate max, respiratory quotient (RQ), body weight and lean body mass after the intervention when compared with before the intervention in the nighttime carbohydrate restriction group (p < 0.05). CONCLUSIONS Our findings suggest that the nighttime carbohydrate restriction method markedly improves fat metabolism even when performed for a short period. This method can be used to reduce body weight in individuals with obesity and enhance athletes' performance. However, it is important to consider the intake of nutrition other than carbohydrates.
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Affiliation(s)
- Takumi Sakamoto
- Graduate School of Health Science, Morinomiya University of Medical Sciences, Osaka 559-8611, Japan;
| | - Shin-ya Ueda
- Faculty of Education, Gifu University, Gifu 501-1193, Japan;
| | - Hidehiro Nakahara
- Department of Acupuncture, Morinomiya University of Medical Sciences, Osaka 559-8611, Japan
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Braden ML, Gwin JA, Leidy HJ. Examining the Direct and Indirect Effects of Postprandial Amino Acid Responses on Markers of Satiety following the Acute Consumption of Lean Beef-Rich Meals in Healthy Women with Overweight. Nutrients 2024; 16:1718. [PMID: 38892651 PMCID: PMC11174850 DOI: 10.3390/nu16111718] [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: 04/30/2024] [Revised: 05/25/2024] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
The consumption of protein-rich foods stimulates satiety more than other macronutrient-rich foods; however, the underlying mechanisms-of-action are not well-characterized. The objective of this study was to identify the direct and indirect effects of postprandial amino acid (AA) responses on satiety. Seventeen women (mean ± SEM, age: 33 ± 1 year; BMI: 27.8 ± 0.1 kg/m2) consumed a eucaloric, plant-based diet containing two servings of lean beef/day (i.e., 7.5 oz (207 g)) for 7 days. During day 6, the participants completed a 12 h controlled-feeding, clinical testing day including repeated satiety questionnaires and blood sampling to assess pre- and postprandial plasma AAs, PYY, and GLP-1. Regression and mediation analyses were completed to assess AA predictors and hormonal mediators. Total plasma AAs explained 41.1% of the variance in perceived daily fullness (p < 0.001), 61.0% in PYY (p < 0.001), and 66.1% in GLP-1 (p < 0.001) concentrations, respectively. Several individual AAs significantly predicted fluctuations in daily fullness, PYY, and GLP-1. In completing mediation analyses, the effect of plasma leucine on daily fullness was fully mediated by circulating PYY concentrations (indirect effect = B: 0.09 [Boot 95% CI: 0.032, 0.17]) as no leucine-fullness direct effect was observed. No other mediators were identified. Although a number of circulating AAs predict satiety, leucine was found to do so through changes in PYY concentrations in middle-aged women.
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Affiliation(s)
- Morgan L. Braden
- Department of Nutritional Sciences, University of Texas at Austin, Austin, TX 78723, USA;
- Department of Pediatrics, Dell Medical School, University of Texas at Austin, Austin, TX 78723, USA
| | - Jess A. Gwin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA;
| | - Heather J. Leidy
- Department of Nutritional Sciences, University of Texas at Austin, Austin, TX 78723, USA;
- Department of Pediatrics, Dell Medical School, University of Texas at Austin, Austin, TX 78723, USA
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3
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Chang YB, Ahn Y, Suh HJ, Jo K. Yeast hydrolysate ameliorates dexamethasone-induced muscle atrophy by suppressing MuRF-1 expression in C2C12 cells and C57BL/6 mice. J Funct Foods 2022. [DOI: 10.1016/j.jff.2022.104985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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4
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Supruniuk E, Żebrowska E, Chabowski A. Branched chain amino acids-friend or foe in the control of energy substrate turnover and insulin sensitivity? Crit Rev Food Sci Nutr 2021; 63:2559-2597. [PMID: 34542351 DOI: 10.1080/10408398.2021.1977910] [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: 12/12/2022]
Abstract
Branched chain amino acids (BCAA) and their derivatives are bioactive molecules with pleiotropic functions in the human body. Elevated fasting blood BCAA concentrations are considered as a metabolic hallmark of obesity, insulin resistance, dyslipidaemia, nonalcoholic fatty liver disease, type 2 diabetes and cardiovascular disease. However, since increased BCAA amount is observed both in metabolically healthy and obese subjects, a question whether BCAA are mechanistic drivers of insulin resistance and its morbidities or only markers of metabolic dysregulation, still remains open. The beneficial effects of BCAA on body weight and composition, aerobic capacity, insulin secretion and sensitivity demand high catabolic potential toward amino acids and/or adequate BCAA intake. On the opposite, BCAA-related inhibition of lipogenesis and lipolysis enhancement may preclude impairment in insulin sensitivity. Thereby, the following review addresses various strategies pertaining to the modulation of BCAA catabolism and the possible roles of BCAA in energy homeostasis. We also aim to elucidate mechanisms behind the heterogeneity of ramifications associated with BCAA modulation.
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Affiliation(s)
- Elżbieta Supruniuk
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Ewa Żebrowska
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
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5
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Hanson ED, Betik AC, Timpani CA, Tarle J, Zhang X, Hayes A. Testosterone suppression does not exacerbate disuse atrophy and impairs muscle recovery that is not rescued by high protein. J Appl Physiol (1985) 2020; 129:5-16. [PMID: 32463734 DOI: 10.1152/japplphysiol.00752.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Androgen deprivation therapy (ADT) decreases muscle mass, force, and physical activity levels, but it is unclear whether disuse atrophy and testosterone suppression are additive. Additionally, conflicting reports exist on load-mediated hypertrophy during ADT and if protein supplementation offsets these deficits. This study sought to determine the role of testosterone suppression and a high-protein diet on 1) immobilization-induced atrophy and 2) muscle regrowth during reloading. Eight-week-old male Fischer 344 rats underwent sham surgery (Sham), castration surgery (ORX), or ORX and a high-casein diet supplemented with branched-chain amino acids (BCAA) (ORX+CAS/AA) followed by 10 days of unilateral immobilization (IMM) and 0, 6, or 14 days of reloading. With IMM, body mass gains were ~8% greater than ORX and ORX+CAS/AA that increased to 15% during reloading (both P < 0.01). IMM reduced muscle mass by 11-34% (all P < 0.01) and extensor digitorum longus and soleus (SOL) force by 21% and 49% (both P < 0.01), respectively, with no group differences. During reloading, castration reduced gastrocnemius mass (~12%) at 6 days and SOL mass (~20%) and SOL force recovery (~46%) at 14 days relative to Sham (all P < 0.05). Specific force reduced castration deficits, indicating that muscle atrophy was a key contributor. IMM decreased SOL cross-sectional area by 30.3% (P < 0.001), with a trend for reduced regrowth in ORX and ORX+CAS/AA following reloading (P = 0.083). Castration did not exacerbate disuse atrophy but may impair recovery of muscle function, with no benefit from a CAS/AA diet during reloading. Examining functional outcomes in addition to muscle mass during dietary interventions provides novel insights into muscle regrowth during ADT.NEW & NOTEWORTHY Low testosterone levels during skeletal muscle disuse did not worsen declines in muscle mass and function, although hypogonadism may attenuate recovery during subsequent reloading. Diets high in casein did not improve outcomes during immobilization or reloading. Practical strategies are needed that do not compromise caloric intake yet provide effective protein doses to augment these adverse effects.
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Affiliation(s)
- Erik D Hanson
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, North Carolina.,Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
| | - Andrew C Betik
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia.,Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Cara A Timpani
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia.,Institute for Musculoskeletal Science (AIMSS), Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, Melbourne, Victoria, Australia
| | - John Tarle
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
| | - Xinmei Zhang
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
| | - Alan Hayes
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia.,Institute for Musculoskeletal Science (AIMSS), Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, Melbourne, Victoria, Australia
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6
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Ma X, Yu M, Liu Z, Deng D, Cui Y, Tian Z, Wang G. Effect of amino acids and their derivatives on meat quality of finishing pigs. Journal of Food Science and Technology 2020; 57:404-412. [PMID: 32116350 DOI: 10.1007/s13197-019-04077-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/19/2019] [Accepted: 08/29/2019] [Indexed: 12/14/2022]
Abstract
Amino acids provide key nutritional value, and significantly contribute to taste and flavor of meat. Here, we review the role of free amino acids in the muscle fibers in meat quality and sensory signals. We furthermore discuss how dietary supplementation of free amino acids and their derivatives (e.g. tryptophan, threonine, arginine, lysine, leucine, glutamate, threonine, sarcosine, betaines, and cysteamine) can influence these attributes. The available data shows that the quality of the meat is subject to the amino acids that are provided in the animal feed.
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Affiliation(s)
- Xianyong Ma
- 1Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- 2The Key Laboratory of Animal Nutrition and Feed Science, South China, Ministry of Agriculture, Guangzhou, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou, China
- Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, 510640 China
| | - Miao Yu
- 1Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- 2The Key Laboratory of Animal Nutrition and Feed Science, South China, Ministry of Agriculture, Guangzhou, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou, China
- Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, 510640 China
| | - Zhichang Liu
- 1Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- 2The Key Laboratory of Animal Nutrition and Feed Science, South China, Ministry of Agriculture, Guangzhou, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou, China
- Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, 510640 China
| | - Dun Deng
- 1Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- 2The Key Laboratory of Animal Nutrition and Feed Science, South China, Ministry of Agriculture, Guangzhou, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou, China
- Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, 510640 China
| | - Yiyan Cui
- 1Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- 2The Key Laboratory of Animal Nutrition and Feed Science, South China, Ministry of Agriculture, Guangzhou, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou, China
- Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, 510640 China
| | - Zhimei Tian
- 1Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- 2The Key Laboratory of Animal Nutrition and Feed Science, South China, Ministry of Agriculture, Guangzhou, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou, China
- Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, 510640 China
| | - Gang Wang
- 1Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- 2The Key Laboratory of Animal Nutrition and Feed Science, South China, Ministry of Agriculture, Guangzhou, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou, China
- Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, 510640 China
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7
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A biotechnological approach for the production of branched chain amino acid containing bioactive peptides to improve human health: A review. Food Res Int 2020; 131:109002. [PMID: 32247480 DOI: 10.1016/j.foodres.2020.109002] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/21/2019] [Accepted: 01/12/2020] [Indexed: 12/20/2022]
Abstract
Improper nutrition provokes many types of chronic diseases and health problems, which consequently are associated with particularly high costs of treatments. Nowadays, consumer's interest in healthy eating is shifting towards specific foods or food ingredients. As a consequence, bioactive peptides as a promising source of health promoting food additives are currently an intensely debated topic in research. Process design is still on its early stages and is significantly influenced by important preliminary decisions. Thus, parameters like peptide bioactivity within the product, selection of the protein source, enzyme selection for hydrolysis, peptide enrichment method, as well as stability of the peptides within the food matrix and bioavailability are sensitive decision points, which have to be purposefully coordinated, as they are directly linked to amino acid content and structure properties of the peptides. Branched chain amino acids (BCAA) are essential components for humans, possessing various important physiologic functions within the body. Incorporated within peptide sequences, they may induce dual functions, when used as nutraceuticals in functional food, thus preserving the foodstuff and prevent several widespread diseases. Furthermore, there is evidence that consuming this peptide-class can be a nutritional support for elderly people or improve human health to prevent diseases caused by incorrect nutrition. Based on the knowledge about the role of BCAA within various peptide functions, discussed in the review, special attention is given to different approaches for systematic selection of the protein source and enzymes used in hydrolysis, as well as suitable peptide enrichment methods, thereby showing current trends in research.
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8
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Exercise Mitigates the Loss of Muscle Mass by Attenuating the Activation of Autophagy during Severe Energy Deficit. Nutrients 2019; 11:nu11112824. [PMID: 31752260 PMCID: PMC6893734 DOI: 10.3390/nu11112824] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 10/30/2019] [Accepted: 11/14/2019] [Indexed: 01/07/2023] Open
Abstract
The loss of skeletal muscle mass with energy deficit is thought to be due to protein breakdown by the autophagy-lysosome and the ubiquitin-proteasome systems. We studied the main signaling pathways through which exercise can attenuate the loss of muscle mass during severe energy deficit (5500 kcal/day). Overweight men followed four days of caloric restriction (3.2 kcal/kg body weight day) and prolonged exercise (45 min of one-arm cranking and 8 h walking/day), and three days of control diet and restricted exercise, with an intra-subject design including biopsies from muscles submitted to distinct exercise volumes. Gene expression and signaling data indicate that the main catabolic pathway activated during severe energy deficit in skeletal muscle is the autophagy-lysosome pathway, without apparent activation of the ubiquitin-proteasome pathway. Markers of autophagy induction and flux were reduced by exercise primarily in the muscle submitted to an exceptional exercise volume. Changes in signaling are associated with those in circulating cortisol, testosterone, cortisol/testosterone ratio, insulin, BCAA, and leucine. We conclude that exercise mitigates the loss of muscle mass by attenuating autophagy activation, blunting the phosphorylation of AMPK/ULK1/Beclin1, and leading to p62/SQSTM1 accumulation. This includes the possibility of inhibiting autophagy as a mechanism to counteract muscle loss in humans under severe energy deficit.
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9
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Duan Y, Zheng C, Zhong Y, Song B, Yan Z, Kong X, Deng J, Li F, Yin Y. Beta-hydroxy beta-methyl butyrate decreases muscle protein degradation via increased Akt/FoxO3a signaling and mitochondrial biogenesis in weanling piglets after lipopolysaccharide challenge. Food Funct 2019; 10:5152-5165. [PMID: 31373594 DOI: 10.1039/c9fo00769e] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The aim of this study was to investigate the effects of dietary β-hydroxy-β-methylbutyrate (HMB) on lipopolysaccharide (LPS)-induced muscle atrophy and to investigate the mechanisms involved. Sixty pigs (21 ± 2 days old, 5.86 ± 0.18 kg body weight) were used in a 2 × 3 factorial design and the main factors included diet (0, 0.60%, or 1.20% HMB) and immunological challenge (LPS or saline). After 15 d of treatment with LPS and/or HMB, growth performance, blood parameters, and muscle protein degradation rate were measured. The results showed that in LPS-injected pigs, 0.60% HMB supplementation increased the average daily gain and average daily feed intake and decreased the feed : gain ratio (P < 0.05), with a concurrent increase of lean percentage. Moreover, 0.60% HMB supplementation decreased the serum concentrations of blood urea nitrogen, IL-1β, and TNF-α and the rate of protein degradation as well as cell apoptosis in selected muscles (P < 0.05). In addition, dietary HMB supplementation (0.60%) regulated the expression of genes involved in mitochondrial biogenesis and increased the phosphorylation of Akt and Forkhead Box O3a (FoxO3a) in selected muscles, accompanied by decreased protein expression of muscle RING finger 1 and muscle atrophy F-box. These results indicate that HMB may exert protective effects against LPS-induced muscle atrophy by normalizing the Akt/FoxO3a axis that regulates ubiquitin proteolysis and by improving mitochondrial biogenesis.
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Affiliation(s)
- Yehui Duan
- 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, Changsha 410125, China.
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10
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Lee HW, Baker E, Lee KM, Persinger AM, Hawkins W, Puppa M. Effects of low-dose leucine supplementation on gastrocnemius muscle mitochondrial content and protein turnover in tumor-bearing mice. Appl Physiol Nutr Metab 2019; 44:997-1004. [PMID: 30768366 DOI: 10.1139/apnm-2018-0765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Many forms of cancer are associated with loss of lean body mass, commonly attributed to decreased protein synthesis and stimulation of proteolytic pathways within the skeletal muscle. Leucine has been shown to improve protein synthesis, insulin signaling, and mitochondrial biogenesis, which are key signaling pathways influenced by tumor signaling. The purpose of this study was to examine the effects of leucine supplementation on mitochondrial biogenesis and protein turnover in tumor-bearing mice. Twenty male C57BL/6 mice were divided into 4 groups (n = 5): Chow, leucine (Leu), Lewis lung carcinoma (LLC) implant, and LLC+Leu. At 9-10 weeks of age, mice were inoculated and supplemented with 5% leucine (w/w) in the diet. C2C12 myotubes were treated with 2.5 mmol/L leucine and 25% LLC conditioned media to further elucidate the direct influence of the tumor and leucine on the muscle. Measures of protein synthesis, mitochondrial biogenesis, and inflammation in the gastrocnemius were assessed via Western blot analysis. Gastrocnemius mass was decreased in LLC+Leu relative to LLC (p = 0.040). Relative protein synthesis rate was decreased in LLC mice (p = 0.001). No change in protein synthesis was observed in myotubes. Phosphorylation of STAT3 was decreased in the Leu group relative to the control in both mice (p = 0.019) and myotubes (p = 0.02), but did not significantly attenuate the inflammatory effect of LLC implantation (p = 0.619). LLC decreased markers of mitochondrial content; however, PGC-1α was increased in LLC+Leu relative to LLC (p = 0.001). While leucine supplementation was unable to preserve protein synthesis or mitochondrial content associated with LLC implantation, it was able to increase mitochondrial biogenesis signaling. Novelty This study provides novel insights on the effect of leucine supplementation on mitochondrial biogenesis and protein turnover in tumor-bearing mice. Leucine increased signaling for mitochondrial biogenesis in the skeletal muscle. Leucine supplementation decreased inflammatory signaling in skeletal muscle.
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Affiliation(s)
- Harold W Lee
- School of Health Studies, University of Memphis, Memphis, TN 38152, USA.,School of Health Studies, University of Memphis, Memphis, TN 38152, USA
| | - Ella Baker
- School of Health Studies, University of Memphis, Memphis, TN 38152, USA.,School of Health Studies, University of Memphis, Memphis, TN 38152, USA
| | - Kevin M Lee
- School of Health Studies, University of Memphis, Memphis, TN 38152, USA.,School of Health Studies, University of Memphis, Memphis, TN 38152, USA
| | - Aaron M Persinger
- School of Health Studies, University of Memphis, Memphis, TN 38152, USA.,School of Health Studies, University of Memphis, Memphis, TN 38152, USA
| | - William Hawkins
- School of Health Studies, University of Memphis, Memphis, TN 38152, USA.,School of Health Studies, University of Memphis, Memphis, TN 38152, USA
| | - Melissa Puppa
- School of Health Studies, University of Memphis, Memphis, TN 38152, USA.,School of Health Studies, University of Memphis, Memphis, TN 38152, USA
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11
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Leucine regulates α-amylase and trypsin synthesis in dairy calf pancreatic tissue in vitro via the mammalian target of rapamycin signalling pathway. Animal 2019; 13:1899-1906. [DOI: 10.1017/s1751731118003683] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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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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Shi YG, Zhang N, Guo QQ, Guan HN, Ikeda S, Guo CH, Piekoszewski W, Kalenik TK, Motkina E. Effects of casein non-phosphopeptide on the development of rat muscle analyzed using computed tomography scanning technology. Food Funct 2018; 9:5805-5812. [PMID: 30352111 DOI: 10.1039/c8fo01405a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of casein non-phosphopeptide (CNPP) on the muscle development of healthy rats and selected blood hormones levels were investigated. CT technology and the ELISA kit were employed to detect the cross-sectional area of each muscle group and blood hormone levels, respectively. The cross-sectional area of the trunk and lower limb muscles of resistance exercise group (REG) rats that were administered a high daily dose of CNPP for 50 days increased more significantly than that of the blank group rats, no exercise group (NEG) rats administered with the same daily dose of CNPP, and REG rats administered with the same daily dose of lactalbumin (P < 0.05).The more enhanced development of trunk and lower limb muscles in CNPP-administered REG rats was associated with a higher blood level of insulin, while no clear trends in blood levels of growth hormone and testosterone were observed. The present results have demonstrated that a combination of physical exercise and diet supplementation with CNPP can synergistically improve muscle mass.
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Affiliation(s)
- Yan-Guo Shi
- Key Laboratory of Food Science and Engineering of Heilongjiang Province, College of Food Engineering, Harbin University of Commerce, 36# No. 138, Tongda Street, Daoli District, Harbin 150076, P R China.
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14
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Chen J, Su W, Kang B, Jiang Q, Zhao Y, Fu C, Yao K. Supplementation with α-ketoglutarate to a low-protein diet enhances amino acid synthesis in tissues and improves protein metabolism in the skeletal muscle of growing pigs. Amino Acids 2018; 50:1525-1537. [PMID: 30167964 DOI: 10.1007/s00726-018-2618-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/10/2018] [Indexed: 12/17/2022]
Abstract
α-Ketoglutarate (AKG) is a crucial intermediate in the tricarboxylic acid (TCA) cycle and can be used for the production of ATP and amino acids in animal tissues. However, the effect of AKG on the expression patterns of genes involved in muscle protein metabolism is largely unknown, and the underlying mechanism remains to be elucidated. Therefore, we used young pigs to investigate the effects of a low crude protein (CP) diet and a low CP diet supplemented with AKG on protein accretion in their skeletal muscle. A total of 27 growing pigs with an initial body weight of 11.96 ± 0.18 kg were assigned randomly to one of the three diets: control (normal recommended 20% CP, NP), low CP (17% CP, LP), or low CP supplemented with 1% AKG (ALP). The pigs were fed their respective diets for 35 days. Free amino acid (AA) profile and hormone levels in the serum, and the expression of genes implicated in protein metabolism in skeletal muscle were examined. Results showed that compared with the control group or LP group, low-protein diets supplemented with AKG enhanced serum and intramuscular free AA concentrations, the mRNA abundances of AA transporters, and serum concentrations of insulin-like growth factor-1 (IGF-1), activated the mammalian target of rapamycin (mTOR) pathway, and decreased serum urea concentration and the mRNA levels for genes related to muscle protein degradation (P < 0.05). In conclusion, these results indicated that addition of AKG to a low-protein diet promotes amino acid synthesis in tissues and improves protein metabolism in skeletal muscle.
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Affiliation(s)
- Jiashun Chen
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, Hunan, China.,Key Laboratory of Agro-ecological Processes in Subtropical Region, Hunan Provincial Engineering Research Center of Healthy Livestock, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, Hunan, China
| | - Wenxuan Su
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Hunan Provincial Engineering Research Center of Healthy Livestock, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, Hunan, China
| | - Baoju Kang
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, Hunan, China
| | - Qian Jiang
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Hunan Provincial Engineering Research Center of Healthy Livestock, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, Hunan, China
| | - Yurong Zhao
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, Hunan, China
| | - Chenxing Fu
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, Hunan, China. .,Hunan Collaborative Innovation Center for Utilization of Botanical Functional Ingredients and Hunan Collaborative Innovation Center of Animal Production Safety, Changsha, 410128, Hunan, China.
| | - Kang Yao
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, Hunan, China. .,Key Laboratory of Agro-ecological Processes in Subtropical Region, Hunan Provincial Engineering Research Center of Healthy Livestock, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, Hunan, China.
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15
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A. R, Agrawal N, Kumar H, Kumar V. Emerging role of branched chain amino acids in metabolic disorders: A mechanistic review. PHARMANUTRITION 2018. [DOI: 10.1016/j.phanu.2018.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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16
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Yanagisawa H, Ishii T, Endo K, Kawakami E, Nagao K, Miyashita T, Akiyama K, Watabe K, Komatsu M, Yamamoto D, Eto Y. L-leucine and SPNS1 coordinately ameliorate dysfunction of autophagy in mouse and human Niemann-Pick type C disease. Sci Rep 2017; 7:15944. [PMID: 29162837 PMCID: PMC5698481 DOI: 10.1038/s41598-017-15305-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 10/24/2017] [Indexed: 12/25/2022] Open
Abstract
Lysosomal storage disorders are characterized by progressive accumulation of undigested macromolecules within the cell due to lysosomal dysfunction. 573C10 is a Schwann cell line derived from a mouse model of Niemann-Pick type C disease-1, NPC (−/−). Under serum-starved conditions, NPC (−/−) cells manifested impaired autophagy accompanied by an increase in the amount of p62 and lysosome enlargement. Addition of L-leucine to serum-starved NPC (−/−) cells ameliorated the enlargement of lysosomes and the p62 accumulation. Similar autophagy defects were observed in NPC (−/−) cells even without serum starvation upon the knockdown of Spinster-like 1 (SPNS1), a putative transporter protein thought to function in lysosomal recycling. Conversely, SPNS1 overexpression impeded the enlargement of lysosomes, p62 accumulation and mislocalization of the phosphorylated form of the mechanistic Target of rapamycin in NPC (−/−) cells. In addition, we found a reduction in endogenous SPNS1 expression in fibroblasts derived from NPC-1 patients compared with normal fibroblasts. We propose that SPNS1-dependent L-leucine export across the lysosomal membrane is a key step for triggering autophagy, and that this mechanism is impaired in NPC-1.
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Affiliation(s)
- Hiroko Yanagisawa
- Advanced Clinical Research Center, Institute for Neurological Disorders, Kawasaki, Japan.
| | - Tomohiro Ishii
- Division of Pharmacology, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Kentaro Endo
- Center for Basic Technology Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Emiko Kawakami
- Center for Basic Technology Research, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Kazuaki Nagao
- Department of Molecular Genetics, Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan
| | - Toshiyuki Miyashita
- Department of Molecular Genetics, Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan
| | - Keiko Akiyama
- Advanced Clinical Research Center, Institute for Neurological Disorders, Kawasaki, Japan
| | - Kazuhiko Watabe
- Department of Medical Technology, Faculty of Health Sciences, Kyorin University, Tokyo, Japan
| | - Masaaki Komatsu
- Department of Biochemistry, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Daisuke Yamamoto
- Division of Neurogenetics, Graduate School of Life Science, Tohoku University, Sendai, Japan
| | - Yoshikatsu Eto
- Advanced Clinical Research Center, Institute for Neurological Disorders, Kawasaki, Japan.
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17
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Bai S, Pan S, Zhang K, Ding X, Wang J, Zeng Q, Xuan Y, Su Z. Long-term effect of dietary overload lithium on the glucose metabolism in broiler chickens. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 54:191-198. [PMID: 28778020 DOI: 10.1016/j.etap.2017.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/15/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
Lithium, like insulin, activates glycogen synthase and stimulates glucose transport in rat adipocytes. To investigate the effect of dietary overload lithium on glucose metabolism in broiler chickens, one-day-old chicks were fed a basal diet supplemented with 0 (control) or 100mg lithium/kg (overload lithium) for 35days. Compared to controls, glucose disappearance rates were lower (p=0.035) 15-120min after glucose gavage, and blood glucose concentrations were lower (p=0.038) 30min after insulin injection in overload lithium broilers. Overload lithium decreased (p<0.05) glycogen and glucose-6-phosphate concentrations in liver, but increased (p<0.05) their concentrations in pectoralis major. Overload lithium increased (p<0.05) mRNA expression of glucose transporter (GLUT) 3 and GLUT9 in liver, and GLUT1, GLUT3, GLUT8, and GLUT9 in pectoralis major, but decreased (p<0.05) cytosolic phosphoenolpyruvate carboxykinase (PEPCK) in liver and mitochondrial PEPCK in pectoralis major. These results suggest that dietary overload lithium decreases glucose tolerance and gluconeogenesis, but increases insulin sensitivity and glucose transport in broiler chickens.
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Affiliation(s)
- Shiping Bai
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Shuqin Pan
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
| | - Keying Zhang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
| | - Xuemei Ding
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
| | - Jianping Wang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
| | - Qiufeng Zeng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
| | - Yue Xuan
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
| | - Zuowei Su
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
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18
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Rudar M, Zhu CL, de Lange CF. Dietary Leucine Supplementation Decreases Whole-Body Protein Turnover before, but Not during, Immune System Stimulation in Pigs. J Nutr 2017; 147:45-51. [PMID: 27798336 DOI: 10.3945/jn.116.236893] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 07/10/2016] [Accepted: 10/03/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Immune system stimulation (ISS) adversely affects protein metabolism and reduces pig productivity. Leu has a regulatory role in skeletal muscle and whole-body protein turnover, which may be affected by ISS. OBJECTIVE We sought to determine the effect of supplemental Leu intake on whole-body protein turnover in pigs before and during ISS. METHODS Pigs [mean ± SD initial body weight (BW): 10.6 ± 1.1 kg] were surgically fitted with jugular vein catheters and assigned to 1 of 3 treatments: 1.36% standardized ileal-digestible (SID) Leu (CON; n = 13); 2.04% SID Leu (LEU-M; n = 8); and 2.72% SID Leu (LEU-H; n = 7). Pigs were infused continuously with 0.66 ± 0.05 mmol 15N ⋅ kg BW-1 ⋅ d-1 to determine whole-body protein kinetics. The study consisted of a 72-h prechallenge period followed by a 36-h challenge period. At the start of the challenge period, ISS was induced in all LEU-M and LEU-H pigs and half of the CON pigs with LPS (ISS+); the remaining CON pigs were administered saline (ISS-). RESULTS Whole-body protein synthesis (309, 273, and 260 ± 14 mmol N ⋅ kg BW-1 ⋅ d-1 for CON, LEU-M, and LEU-H pigs, respectively) and protein degradation (233, 203, and 185 ± 14 mmol N ⋅ kg BW-1 ⋅ d-1 for CON, LEU-M, and LEU-H pigs, respectively) were reduced with increasing Leu intake during the prechallenge period (P < 0.05). ISS reduced whole-body protein synthesis (203 compared with 169 ± 12 mmol N ⋅ kg BW-1 ⋅ d-1 for ISS- and ISS+ pigs fed CON, respectively; P < 0.05) and protein deposition (PD) (64.9 compared with 45.0 ± 2.9 mmol N ⋅ kg BW-1 ⋅ d-1 for ISS- and ISS+ pigs fed CON, respectively; P < 0.01), whereas ISS did not affect whole-body protein degradation. Leu intake did not affect whole-body protein synthesis or degradation in ISS+ pigs. CONCLUSIONS Our results indicate that supplemental Leu intake improves the efficiency of PD rather than PD directly in healthy pigs but did not affect whole-body protein turnover during ISS.
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Affiliation(s)
- Marko Rudar
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
| | - Cuilan L Zhu
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
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19
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Zheng L, Wei H, He P, Zhao S, Xiang Q, Pang J, Peng J. Effects of Supplementation of Branched-Chain Amino Acids to Reduced-Protein Diet on Skeletal Muscle Protein Synthesis and Degradation in the Fed and Fasted States in a Piglet Model. Nutrients 2016; 9:nu9010017. [PMID: 28036018 PMCID: PMC5295061 DOI: 10.3390/nu9010017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/08/2016] [Accepted: 12/12/2016] [Indexed: 12/16/2022] Open
Abstract
Supplementation of branched-chain amino acids (BCAA) has been demonstrated to promote skeletal muscle mass gain, but the mechanisms underlying this observation are still unknown. Since the regulation of muscle mass depends on a dynamic equilibrium (fasted losses–fed gains) in protein turnover, the aim of this study was to investigate the effects of BCAA supplementation on muscle protein synthesis and degradation in fed/fasted states and the related mechanisms. Fourteen 26- (Experiment 1) and 28-day-old (Experiment 2) piglets were fed reduced-protein diets without or with supplemental BCAA. After a four-week acclimation period, skeletal muscle mass and components of anabolic and catabolic signaling in muscle samples after overnight fasting were determined in Experiment 1. Pigs in Experiment 2 were implanted with carotid arterial, jugular venous, femoral arterial and venous catheters, and fed once hourly along with the intravenous infusion of NaH13CO3 for 2 h, followed by a 6-h infusion of [1-13C]leucine. Muscle leucine kinetics were measured using arteriovenous difference technique. The mass of most muscles was increased by BCAA supplementation. During feeding, BCAA supplementation increased leucine uptake, protein synthesis, protein degradation and net transamination. The greater increase in protein synthesis than in protein degradation resulted in elevated protein deposition. Protein synthesis was strongly and positively correlated with the intramuscular net production of α-ketoisocaproate (KIC) and protein degradation. Moreover, BCAA supplementation enhanced the fasted-state phosphorylation of protein translation initiation factors and inhibited the protein-degradation signaling of ubiquitin-proteasome and autophagy-lysosome systems. In conclusion, supplementation of BCAA to reduced-protein diet increases fed-state protein synthesis and inhibits fasted-state protein degradation, both of which could contribute to the elevation of skeletal muscle mass in piglets. The effect of BCAA supplementation on muscle protein synthesis is associated with the increase in protein degradation and KIC production in the fed state.
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Affiliation(s)
- Liufeng Zheng
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Hongkui Wei
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China.
| | - Pingli He
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100094, China.
| | - Shengjun Zhao
- Department of Feed Science, Wuhan Polytechnic University, Wuhan 430023, China.
| | - Quanhang Xiang
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Jiaman Pang
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Jian Peng
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China.
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20
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Carbohydrate intake and resistance-based exercise: are current recommendations reflective of actual need? Br J Nutr 2016; 116:2053-2065. [PMID: 27993175 DOI: 10.1017/s0007114516003949] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Substantial research has been completed examining the impact of carbohydrate (CHO) intake on endurance exercise, whereas its role in resistance-based exercise performance, adaptation and cell signalling has yet to be fully characterised. This empirical shortcoming has precluded the ability to establish specific CHO recommendations for resistance exercise. This results in recommendations largely stemming from findings based on endurance exercise and/or anecdotal evidence despite the distinct energetic demands and molecular responses mediating adaptation from endurance- and resistance-based exercise. Moreover, the topic of CHO and exercise has become one of polarising nature with divergent views - some substantiated, others lacking evidence. Current literature suggests a moderately high daily CHO intake (3-7 g/kg per d) for resistance training, which is thought to prevent glycogen depletion and facilitate performance and adaptation. However, contemporary investigation, along with an emerging understanding of the molecular underpinnings of resistance exercise adaptation, may suggest that such an intake may not be necessary. In addition to the low likelihood of true glycogen depletion occurring in response to resistance exercise, a diet restrictive in CHO may not be detrimental to acute resistance exercise performance or the cellular signalling activity responsible for adaptation, even when muscle glycogen stores are reduced. Current evidence suggests that signalling of the mammalian target of rapamycin complex 1, the key regulatory kinase for gene translation (protein synthesis), is unaffected by CHO restriction or low muscular glycogen concentrations. Such findings may call into question the current view and subsequent recommendations of CHO intake with regard to resistance-based exercise.
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21
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Duan Y, Guo Q, Wen C, Wang W, Li Y, Tan B, Li F, Yin Y. Free Amino Acid Profile and Expression of Genes Implicated in Protein Metabolism in Skeletal Muscle of Growing Pigs Fed Low-Protein Diets Supplemented with Branched-Chain Amino Acids. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:9390-9400. [PMID: 27960294 DOI: 10.1021/acs.jafc.6b03966] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Revealing the expression patterns of genes involved in protein metabolism as affected by diets would be useful for further clarifying the importance of the balance among the branched-chain amino acids (BCAAs), which include leucine (Leu), isoleucine (Ile), and valine (Val). Therefore, we used growing pigs to explore the effects of different dietary BCAA ratios on muscle protein metabolism. The Leu:Ile:Val ratio was 1:0.51:0.63 (20% crude protein, CP), 1:1:1 (17% CP), 1:0.75:0.75 (17% CP), 1:0.51:0.63 (17% CP), and 1:0.25:0.25 (17% CP), respectively. Results showed that compared with the control group, low-protein diets with the BCAA ratio ranging from 1:0.75:0.75 to 1:0.25:0.25 elevated muscle free amino acid (AA) concentrations and AA transporter expression, significantly activated the mammalian target of rapamycin complex 1 pathway, and decreased serum urea nitrogen content and the mRNA expression of genes related to muscle protein degradation (P < 0.05). In conclusion, these results indicated that maintaining the dietary Leu:Ile:Val ratio within 1:0.25:0.25-1:0.75:0.75 in low-protein diets (17% CP) would facilitate the absorption and utilization of free AA and result in improved protein metabolism and muscle growth.
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Affiliation(s)
- Yehui Duan
- 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, Changsha 410125, China
- University of Chinese Academy of Sciences , Beijing 100039, China
| | - Qiuping Guo
- 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, Changsha 410125, China
- University of Chinese Academy of Sciences , Beijing 100039, China
| | - Chaoyue Wen
- Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University , Changsha, Hunan 410018, China
| | - Wenlong Wang
- Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University , Changsha, Hunan 410018, China
| | - Yinghui Li
- 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, Changsha 410125, China
- University of Chinese Academy of Sciences , Beijing 100039, China
| | - Bie Tan
- 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, Changsha 410125, China
| | - Fengna Li
- 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, Changsha 410125, China
- Hunan Co-Innovation Center of Animal Production Safety, CICAPS; Hunan Collaborative Innovation Center for Utilization of Botanical Functional Ingredients , Changsha 410128, China
| | - Yulong Yin
- 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, Changsha 410125, China
- Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University , Changsha, Hunan 410018, China
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22
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Sato T, Ito Y, Nagasawa T. L-Lysine suppresses myofibrillar protein degradation and autophagy in skeletal muscles of senescence-accelerated mouse prone 8. Biogerontology 2016; 18:85-95. [PMID: 27752791 DOI: 10.1007/s10522-016-9663-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/13/2016] [Indexed: 01/01/2023]
Abstract
Sarcopenia is a condition of the loss of muscle mass that is associated with aging and that increases the risk for bedridden state, thereby warranting studies of interventions that attenuate sarcopenia. Here the effects of 2-month dietary L-lysine (Lys) supplementation (1.5-3.0 %) on myofibrillar protein degradation and major proteolytic systems were investigated in senescence-accelerated mouse prone 8 (SAMP8). At 36 weeks of age, skeletal muscle and lean body mass was reduced in SAMP8 when compared with control senescence-accelerated mouse resistant 1 (SAMR1). The myofibrillar protein degradation, which was evaluated by the release of 3-methylhistidine, was stimulated in SAMP8, and the autophagy activity, which was evaluated by light chain 3-II, was stimulated in the skeletal muscle of SAMP8. The activation of ubiquitin-proteasome system was not observed in the muscles of SAMP8. However, myofibrillar protein degradation and autophagic activity in skeletal muscles of SAMP8 were suppressed by dietary intake of 3.0 % Lys. The present data indicate that myofibrillar protein degradation by bulk autophagy is stimulated in the skeletal muscles of SAMP8 and that dietary Lys supplementation attenuates sarcopenia in SAMP8 by suppressing autophagic proteolysis.
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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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23
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Sato T, Ito Y, Nagasawa T. Regulatory effects of the L-lysine metabolites, L-2-aminoadipic acid and L-pipecolic acid, on protein turnover in C2C12 myotubes. Biosci Biotechnol Biochem 2016; 80:2168-2175. [PMID: 27427787 DOI: 10.1080/09168451.2016.1210499] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We previously showed that L-lysine (Lys) and a metabolite of Lys, L-saccharopine, suppressed autophagic proteolysis in C2C12 myotubes. However, the effects of other metabolites of Lys on protein turnover were unknown. We here investigated the effect of the Lys metabolites, L-2-aminoadipic acid (2-AA) and L-pipecolic acid (Pip), on protein turnover in C2C12 myotubes. 2-AA suppressed myofibrillar protein degradation evaluated by the 3-methylhistidine and autophagy activity evaluated by light chain 3-II at lower concentration (100 μM) than did Lys. On the other hand, Pip stimulated the mammalian target of rapamycin signaling activity. Additionally, 100 μM Pip significantly increased the rates of protein synthesis whereas 100 μM Lys had no effect. These results indicate that in C2C12 myotubes, 2-AA could suppress autophagy and Pip could stimulate the rates of protein synthesis, and these metabolites may contribute to exert effect of Lys on protein turnover.
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Affiliation(s)
- Tomonori Sato
- a Department of Bioresources Science , The United Graduate School of Agricultural Sciences, Iwate University , Morioka , Japan
| | - Yoshiaki Ito
- b Department of Biological Chemistry and Food Science , Graduate School of Agriculture, Iwate University , Morioka , Japan
| | - Takashi Nagasawa
- b Department of Biological Chemistry and Food Science , Graduate School of Agriculture, Iwate University , Morioka , Japan
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24
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Ananieva EA, Powell JD, Hutson SM. Leucine Metabolism in T Cell Activation: mTOR Signaling and Beyond. Adv Nutr 2016; 7:798S-805S. [PMID: 27422517 PMCID: PMC4942864 DOI: 10.3945/an.115.011221] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In connection with the increasing interest in metabolic regulation of the immune response, this review discusses current advances in understanding the role of leucine and leucine metabolism in T lymphocyte (T cell) activation. T cell activation during the development of an immune response depends on metabolic reprogramming to ensure that sufficient nutrients and energy are taken up by the highly proliferating T cells. Leucine has been described as an important essential amino acid and a nutrient signal that activates complex 1 of the mammalian target of rapamycin (mTORC1), which is a critical regulator of T cell proliferation, differentiation, and function. The role of leucine in these processes is further discussed in relation to amino acid transporters, leucine-degrading enzymes, and other metabolites of leucine metabolism. A new model of T cell regulation by leucine is proposed and outlines a chain of events that leads to the activation of mTORC1 in T cells.
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Affiliation(s)
- Elitsa A Ananieva
- Department of Biochemistry and Nutrition, Des Moines University, Des Moines, IA;
| | - Jonathan D Powell
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD; and
| | - Susan M Hutson
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA
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Yoon MS. The Emerging Role of Branched-Chain Amino Acids in Insulin Resistance and Metabolism. Nutrients 2016; 8:nu8070405. [PMID: 27376324 PMCID: PMC4963881 DOI: 10.3390/nu8070405] [Citation(s) in RCA: 271] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/01/2016] [Accepted: 06/27/2016] [Indexed: 12/12/2022] Open
Abstract
Insulin is required for maintenance of glucose homeostasis. Despite the importance of insulin sensitivity to metabolic health, the mechanisms that induce insulin resistance remain unclear. Branched-chain amino acids (BCAAs) belong to the essential amino acids, which are both direct and indirect nutrient signals. Even though BCAAs have been reported to improve metabolic health, an increased BCAA plasma level is associated with a high risk of metabolic disorder and future insulin resistance, or type 2 diabetes mellitus (T2DM). The activation of mammalian target of rapamycin complex 1 (mTORC1) by BCAAs has been suggested to cause insulin resistance. In addition, defective BCAA oxidative metabolism might occur in obesity, leading to a further accumulation of BCAAs and toxic intermediates. This review provides the current understanding of the mechanism of BCAA-induced mTORC1 activation, as well as the effect of mTOR activation on metabolic health in terms of insulin sensitivity. Furthermore, the effects of impaired BCAA metabolism will be discussed in detail.
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Affiliation(s)
- Mee-Sup Yoon
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Korea.
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26
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van Niekerk G, Isaacs AW, Nell T, Engelbrecht AM. Sickness-Associated Anorexia: Mother Nature's Idea of Immunonutrition? Mediators Inflamm 2016; 2016:8071539. [PMID: 27445441 PMCID: PMC4942670 DOI: 10.1155/2016/8071539] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 02/06/2023] Open
Abstract
During an infection, expansion of immune cells, assembly of antibodies, and the induction of a febrile response collectively place continual metabolic strain on the host. These considerations also provide a rationale for nutritional support in critically ill patients. Yet, results from clinical and preclinical studies indicate that aggressive nutritional support does not always benefit patients and may occasionally be detrimental. Moreover, both vertebrates and invertebrates exhibit a decrease in appetite during an infection, indicating that such sickness-associated anorexia (SAA) is evolutionarily conserved. It also suggests that SAA performs a vital function during an infection. We review evidence signifying that SAA may present a mechanism by which autophagic flux is upregulated systemically. A decrease in serum amino acids during an infection promotes autophagy not only in immune cells, but also in nonimmune cells. Similarly, bile acids reabsorbed postprandially inhibit hepatic autophagy by binding to farnesoid X receptors, indicating that SAA may be an attempt to conserve autophagy. In addition, augmented autophagic responses may play a critical role in clearing pathogens (xenophagy), in the presentation of epitopes in nonprovisional antigen presenting cells and the removal of damaged proteins and organelles. Collectively, these observations suggest that some patients might benefit from permissive underfeeding.
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Affiliation(s)
- Gustav van Niekerk
- Department of Physiological Sciences, Private Bag X1, Matieland, Stellenbosch 7600, South Africa
| | - Ashwin W. Isaacs
- Department of Physiological Sciences, Private Bag X1, Matieland, Stellenbosch 7600, South Africa
| | - Theo Nell
- Department of Physiological Sciences, Private Bag X1, Matieland, Stellenbosch 7600, South Africa
| | - Anna-Mart Engelbrecht
- Department of Physiological Sciences, Private Bag X1, Matieland, Stellenbosch 7600, South Africa
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Kobayashi Y, Somoto Y, Mitsuyama E, Tanaka A, Yuda N, Nakada H, Yamada A, Yamauchi K, Abe F, Nagasawa T. Supplementation of protein-free diet with whey protein hydrolysates prevents skeletal muscle mass loss in rats. JOURNAL OF NUTRITION & INTERMEDIARY METABOLISM 2016. [DOI: 10.1016/j.jnim.2016.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Zhang S, Chu L, Qiao S, Mao X, Zeng X. Effects of dietary leucine supplementation in low crude protein diets on performance, nitrogen balance, whole-body protein turnover, carcass characteristics and meat quality of finishing pigs. Anim Sci J 2015; 87:911-20. [PMID: 26597995 DOI: 10.1111/asj.12520] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/23/2015] [Accepted: 07/05/2015] [Indexed: 11/29/2022]
Abstract
Eighteen Duroc × Landrace × Yorkshire barrows, with an average initial body weight (BW) of 75.4 ± 2.0 kg, were randomly allotted to one of three diets with six replicates per treatment for 25 days. The diets comprised a normal protein diet (NP, 14.5% crude protein), a low crude protein diet supplemented with 0.27% alanine (LP + Ala, 10.0% crude protein), or a low crude protein diet supplemented with 0.40% leucine (LP + Leu, 10.0% crude protein). The whole-body protein synthesis rate, whole-body protein breakdown rate and protein deposition rate in pigs fed the LP + Leu diet were similar to the NP diet (P > 0.05), and both were significantly higher than pigs fed the LP + Ala diet (P < 0.05). The Longissimus muscle area (LMA) of pigs fed the LP + Leu diet was larger than those fed the LP + Ala diet (P = 0.05). In addition, drip loss and intramuscular fat of pigs fed the LP + Ala diet were higher than that of the others (P < 0.05). In conclusion, supplementation of leucine in low protein diet could stimulate protein deposition and improve the meat quality of finishing pigs more than an alanine-supplemented one.
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Affiliation(s)
- Shihai Zhang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, Beijing
| | - Licui Chu
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, Beijing
| | - Shiyan Qiao
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, Beijing
| | - Xiangbing Mao
- Animal Nutrition Institute, Sichuan Agricultural University, Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Ya'an, Sichuan, China
| | - Xiangfang Zeng
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, Beijing
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Sato T, Ito Y, Nagasawa T. Dietary L-Lysine Suppresses Autophagic Proteolysis and Stimulates Akt/mTOR Signaling in the Skeletal Muscle of Rats Fed a Low-Protein Diet. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:8192-8198. [PMID: 26366928 DOI: 10.1021/acs.jafc.5b03811] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Amino acids, especially L-leucine, regulate protein turnover in skeletal muscle and have attracted attention as a means of increasing muscle mass in people suffering from malnutrition, aging (sarcopenia), or a bedridden state. We previously showed that oral administration of L-lysine (Lys) by gavage suppressed proteolysis in skeletal muscles of fasted rats. However, the intake of Lys in the absence of other dietary components is unlikely in a non-experimental setting, and other dietary components may interfere with the suppressive effect of Lys on proteolysis. We supplemented Lys to a 10% casein diet and investigated the effect of Lys on proteolysis and autophagy, a major proteolytic system, in the skeletal muscle of rats. The rate of proteolysis was evaluated from 3-methylhisitidine (MeHis) released from isolated muscles, in plasma, and excreted in urine. Supplementing lysine with the 10% casein diet decreased the rate of proteolysis induced by intake of a low-protein diet. The upregulated autophagy activity [light chain 3 (LC3)-II/total LC3] caused by a low-protein diet was reduced, and the Akt/mTOR signaling pathway was activated by Lys. Importantly, continuous feeding of a Lys-rich 10% casein diet for 15 days increased the masses of the soleus and gastrocnemius muscles. Taken together, supplementation of Lys to a low-protein diet suppresses autophagic proteolysis through the Akt/mTOR signaling pathway, and continuous feeding of a Lys-rich diet may increase skeletal muscle mass.
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Affiliation(s)
- Tomonori Sato
- Department of Bioresources Science, The United Graduate School of Agricultural Sciences, and ‡Department of Biological Chemistry and Food Science, Graduate School of Agriculture, Iwate University , Morioka, Iwate 020-8550, Japan
| | - Yoshiaki Ito
- Department of Bioresources Science, The United Graduate School of Agricultural Sciences, and ‡Department of Biological Chemistry and Food Science, Graduate School of Agriculture, Iwate University , Morioka, Iwate 020-8550, Japan
| | - Takashi Nagasawa
- Department of Bioresources Science, The United Graduate School of Agricultural Sciences, and ‡Department of Biological Chemistry and Food Science, Graduate School of Agriculture, Iwate University , Morioka, Iwate 020-8550, Japan
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Columbus DA, Steinhoff-Wagner J, Suryawan A, Nguyen HV, Hernandez-Garcia A, Fiorotto ML, Davis TA. Impact of prolonged leucine supplementation on protein synthesis and lean growth in neonatal pigs. Am J Physiol Endocrinol Metab 2015; 309:E601-10. [PMID: 26374843 PMCID: PMC4572453 DOI: 10.1152/ajpendo.00089.2015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 07/28/2015] [Indexed: 11/22/2022]
Abstract
Most low-birth weight infants experience extrauterine growth failure due to reduced nutrient intake as a result of feeding intolerance. The objective of this study was to determine whether prolonged enteral leucine supplementation improves lean growth in neonatal pigs fed a restricted protein diet. Neonatal pigs (n = 14-16/diet, 5 days old, 1.8 ± 0.3 kg) were fed by gastric catheter a whey-based milk replacement diet with either a high protein (HP) or restricted protein (RP) content or RP supplemented with leucine to the same level as in the HP diet (RPL). Pigs were fed 40 ml·kg body wt(-1)·meal(-1) every 4 h for 21 days. Feeding the HP diet resulted in greater total body weight and lean body mass compared with RP-fed pigs (P < 0.05). Masses of the longissimus dorsi muscle, heart, and kidneys were greater in the HP- than RP-fed pigs (P < 0.05). Body weight, lean body mass, and masses of the longissimus dorsi, heart, and kidneys in pigs fed the RPL diet were intermediate to RP- and HP-fed pigs. Protein synthesis and mTOR signaling were increased in all muscles with feeding (P < 0.05); leucine supplementation increased mTOR signaling and protein synthesis rate in the longissimus dorsi (P < 0.05). There was no effect of diet on indices of protein degradation signaling in any tissue (P > 0.05). Thus, when protein intake is chronically restricted, the capacity for leucine supplementation to enhance muscle protein accretion in neonatal pigs that are meal-fed milk protein-based diets is limited.
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Affiliation(s)
- Daniel A Columbus
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Julia Steinhoff-Wagner
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Agus Suryawan
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Hanh V Nguyen
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Adriana Hernandez-Garcia
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Marta L Fiorotto
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Teresa A Davis
- United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
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Attenuation of autophagic-proteolysis in C2C12 cells by saccharopine. Mol Cell Biochem 2015; 410:93-100. [DOI: 10.1007/s11010-015-2541-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 08/18/2015] [Indexed: 12/18/2022]
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Ribeiro CB, Christofoletti DC, Pezolato VA, de Cássia Marqueti Durigan R, Prestes J, Tibana RA, Pereira ECL, de Sousa Neto IV, Durigan JLQ, da Silva CA. Leucine minimizes denervation-induced skeletal muscle atrophy of rats through akt/mtor signaling pathways. Front Physiol 2015; 6:73. [PMID: 25852565 PMCID: PMC4364154 DOI: 10.3389/fphys.2015.00073] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 02/20/2015] [Indexed: 11/20/2022] Open
Abstract
The aim of the present study was to evaluate the effect of leucine treatment (0.30 mM) on muscle weight and signaling of myoproteins related to synthesis and degradation pathways of soleus muscle following seven days of complete sciatic nerve lesion. Wistar rats (n = 24) of 3–4 months of age (192 ± 23 g) were used. The animals were randomly distributed into four experimental groups (n = 6/group): control, treated with leucine (L), denervated (D) and denervated treated with leucine (DL). Dependent measures were proteins levels of AKT, AMPK, mTOR, and ACC performed by Western blot. Leucine induced a reduction in the phosphorylation of AMPK (p < 0.05) by 16% in the L and by 68% in the DL groups as compared with control group. Denervation increased AMPK by 24% in the D group as compared with the control group (p < 0.05). AKT was also modulated by denervation and leucine treatment, highlighted by the elevation of AKT phosphorylation in the D (65%), L (98%) and DL (146%) groups as compared with the control group (p < 0.05). AKT phosphorylation was 49% higher in the D group as compared with the DL group. Furthermore, denervation decreased mTOR phosphorylation by 29% in the D group as compared with the control group. However, leucine treatment induced an increase of 49% in the phosphorylation of mTOR in the L group as compared with the control group, and an increase of 154% in the DL as compared with the D group (p < 0.05). ACC phosphorylation was 20% greater in the D group than the control group. Furthermore, ACC in the soleus was 22% lower in the in the L group and 50% lower in the DL group than the respective control group (p < 0.05). In conclusion, leucine treatment minimized the deleterious effects of denervation on rat soleus muscle by increasing anabolic (AKT and mTOR) and decreasing catabolic (AMPK) pathways. These results may be interesting for muscle recovery following acute denervation, which may contribute to musculoskeletal rehabilitation after denervation.
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Affiliation(s)
- Carolina B Ribeiro
- Programa de Pós-graduação em Ciências do Movimento Humano, Methodist University of Piracicaba, UNIMEP Piracicaba, Brazil
| | - Daiane C Christofoletti
- Programa de Pós-graduação em Ciências do Movimento Humano, Methodist University of Piracicaba, UNIMEP Piracicaba, Brazil
| | - Vitor A Pezolato
- Programa de Pós-graduação em Ciências do Movimento Humano, Methodist University of Piracicaba, UNIMEP Piracicaba, Brazil
| | | | - Jonato Prestes
- Graduate Program of Physical Education, Catholic University of Brasília Brasilia, Brazil
| | - Ramires A Tibana
- Graduate Program of Physical Education, Catholic University of Brasília Brasilia, Brazil
| | - Elaine C L Pereira
- Graduate Program of Science and Technology of Health, University of Brasília Brasilia, Brazil
| | - Ivo V de Sousa Neto
- Graduate Program of Physical Education, Catholic University of Brasília Brasilia, Brazil
| | - João L Q Durigan
- Graduate Program of Science and Technology of Health, University of Brasília Brasilia, Brazil ; Graduate Program of Physical Education, University of Brasília Brasilia, Brazil
| | - Carlos A da Silva
- Programa de Pós-graduação em Ciências do Movimento Humano, Methodist University of Piracicaba, UNIMEP Piracicaba, Brazil
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Abstract
Branched-chain amino acids (BCAAs) are important nutrient signals that have direct and indirect effects. Frequently, BCAAs have been reported to mediate antiobesity effects, especially in rodent models. However, circulating levels of BCAAs tend to be increased in individuals with obesity and are associated with worse metabolic health and future insulin resistance or type 2 diabetes mellitus (T2DM). A hypothesized mechanism linking increased levels of BCAAs and T2DM involves leucine-mediated activation of the mammalian target of rapamycin complex 1 (mTORC1), which results in uncoupling of insulin signalling at an early stage. A BCAA dysmetabolism model proposes that the accumulation of mitotoxic metabolites (and not BCAAs per se) promotes β-cell mitochondrial dysfunction, stress signalling and apoptosis associated with T2DM. Alternatively, insulin resistance might promote aminoacidaemia by increasing the protein degradation that insulin normally suppresses, and/or by eliciting an impairment of efficient BCAA oxidative metabolism in some tissues. Whether and how impaired BCAA metabolism might occur in obesity is discussed in this Review. Research on the role of individual and model-dependent differences in BCAA metabolism is needed, as several genes (BCKDHA, PPM1K, IVD and KLF15) have been designated as candidate genes for obesity and/or T2DM in humans, and distinct phenotypes of tissue-specific branched chain ketoacid dehydrogenase complex activity have been detected in animal models of obesity and T2DM.
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Affiliation(s)
- Christopher J Lynch
- Cellular and Molecular Physiology Department, The Pennsylvania State University, 500 University Drive, MC-H166, Hershey, PA 17033, USA
| | - Sean H Adams
- Arkansas Children's Nutrition Center, and Department of Pediatrics, University of Arkansas for Medical Sciences, 15 Children's Way, Little Rock, AR 72202, USA
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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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Brown LD, Thorn SR, O'Meara MC, Lavezzi JR, Rozance PJ. A physiological increase in insulin suppresses muscle-specific ubiquitin ligase gene activation in fetal sheep with sustained hypoglycemia. Physiol Rep 2014; 2:2/6/e12045. [PMID: 24944291 PMCID: PMC4208658 DOI: 10.14814/phy2.12045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Decreased glucose transfer to the fetus is characteristic of pregnancies complicated by maternal under nutrition and placental insufficiency. Chronic experimental restriction of glucose transfer to the sheep fetus for the final 40% of gestation with a maternal insulin infusion (HG fetuses) results in fetal hypoglycemia, hypoinsulinemia, and decreased rates of fetal growth and protein accretion compared to controls (CON). Lower rates of fetal protein accretion are due to increased fetal protein breakdown and not decreased protein synthesis. However, the specific skeletal muscle pathways responsible for increased protein breakdown have not been determined. Nor has it been determined if low fetal glucose or insulin concentrations are more important for regulating these skeletal muscle protein breakdown pathways. We tested whether chronic restriction of glucose transfer to the fetus increased the ubiquitin-proteosome pathway or autophagy-lysosome pathway in fetal sheep skeletal muscle and found no evidence for an increase in the autophagy-lysosome pathway. However, HG fetuses had increase mRNA expression of MaFBx1 (twofold, P < 0.01) and a trend for increased mRNA expression of MuRF1 (P = 0.08) compared to CON. A subset of chronically hypoglycemic fetuses received an isoglycemic insulin infusion for the final 7 days of the maternal insulin infusion (HG + INS fetuses) and had MaFBx1 and MuRF1 mRNA concentrations similar to CON fetuses. These results demonstrate that fetuses exposed to sustained hypoglycemia have decreased protein accretion due to activation of the skeletal muscle ubiquitin-proteosome pathway and that a fetal hyperinsulinemic clamp can suppress this pathway even in the context of continued hypoglycemia.
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Affiliation(s)
- Laura D Brown
- Perinatal Research Center, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA Center for Women's Health Research, University of Colorado Denver, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Stephanie R Thorn
- Perinatal Research Center, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA Center for Women's Health Research, University of Colorado Denver, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Meghan C O'Meara
- Perinatal Research Center, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA
| | - Jinny R Lavezzi
- Perinatal Research Center, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA
| | - Paul J Rozance
- Perinatal Research Center, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado, USA Center for Women's Health Research, University of Colorado Denver, University of Colorado School of Medicine, Aurora, Colorado, USA
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Lysine suppresses protein degradation through autophagic-lysosomal system in C2C12 myotubes. Mol Cell Biochem 2014; 391:37-46. [PMID: 24532005 DOI: 10.1007/s11010-014-1984-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 01/29/2014] [Indexed: 12/17/2022]
Abstract
Muscle mass is determined between protein synthesis and protein degradation. Reduction of muscle mass leads to bedridden condition and attenuation of resistance to diseases. Moreover, bedridden condition leads to additional muscle loss due to disuse muscle atrophy. In our previous study (Sato et al. 2013), we showed that administered lysine (Lys), one of essential amino acid, suppressed protein degradation in skeletal muscle. In this study, we investigated that the mechanism of the suppressive effects of Lys on skeletal muscle proteolysis in C2C12 cell line. C2C12 myotubes were incubated in the serum-free medium containing 10 mM Lys or 20 mM Lys, and myofibrillar protein degradation was determined by the rates of 3-methylhistidine (MeHis) release from the cells. The mammalian target of rapamycin (mTOR) activity from the phosphorylation levels of p70-ribosormal protein S6 kinase 1 and eIF4E-binding protein 1 and the autophagic-lysosomal system activity from the ratio of LC3-II/I in C2C12 myotubes stimulated by 10 mM Lys for 0-3 h were measured. The rates of MeHis release were markedly reduced by addition of Lys. The autophagic-lysosomal system activity was inhibited upon 30 min of Lys supplementation. The activity of mTOR was significantly increased upon 30 min of Lys supplementation. The suppressive effect of Lys on the proteolysis by the autophagic-lysosomal system was maintained partially when mTOR activity was inhibited by 100 nM rapamycin, suggesting that some regulator other than mTOR signaling, for example, Akt, might also suppress the autophagic-lysosomal system. From these results, we suggested that Lys suppressed the activity of the autophagic-lysosomal system in part through activation of mTOR and reduced myofibrillar protein degradation in C2C12 myotubes.
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Petzke KJ, Freudenberg A, Klaus S. Beyond the role of dietary protein and amino acids in the prevention of diet-induced obesity. Int J Mol Sci 2014; 15:1374-91. [PMID: 24447927 PMCID: PMC3907874 DOI: 10.3390/ijms15011374] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/09/2014] [Accepted: 01/09/2014] [Indexed: 12/22/2022] Open
Abstract
High-protein diets have been shown to prevent the development of diet-induced obesity and can improve associated metabolic disorders in mice. Dietary leucine supplementation can partially mimic this effect. However, the molecular mechanisms triggering these preventive effects remain to be satisfactorily explained. Here we review studies showing a connection between high protein or total amino nitrogen intake and obligatory water intake. High amino nitrogen intake may possibly lower lipid storage, and prevent insulin resistance. Suggestions are made for further systematical studies to explore the relationship between water consumption, satiety, and energy expenditure. Moreover, these examinations should better distinguish between leucine-specific and unspecific effects. Research in this field can provide important information to justify dietary recommendations and strategies in promoting long-term weight loss and may help to reduce health problems associated with the comorbidities of obesity.
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Affiliation(s)
- Klaus J Petzke
- German Institute of Human Nutrition in Potsdam-Rehbruecke (DIfE), Arthur-Scheunert-Allee 114-116, Nuthetal 14558, Germany.
| | - Anne Freudenberg
- German Institute of Human Nutrition in Potsdam-Rehbruecke (DIfE), Arthur-Scheunert-Allee 114-116, Nuthetal 14558, Germany.
| | - Susanne Klaus
- German Institute of Human Nutrition in Potsdam-Rehbruecke (DIfE), Arthur-Scheunert-Allee 114-116, Nuthetal 14558, Germany.
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Huang J, Wang J, Gu L, Bao J, Yin J, Tang Z, Wang L, Yuan W. Effect of a low-protein diet supplemented with ketoacids on skeletal muscle atrophy and autophagy in rats with type 2 diabetic nephropathy. PLoS One 2013; 8:e81464. [PMID: 24303049 PMCID: PMC3841136 DOI: 10.1371/journal.pone.0081464] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 10/14/2013] [Indexed: 02/07/2023] Open
Abstract
A low-protein diet supplemented with ketoacids maintains nutritional status in patients with diabetic nephropathy. The activation of autophagy has been shown in the skeletal muscle of diabetic and uremic rats. This study aimed to determine whether a low-protein diet supplemented with ketoacids improves muscle atrophy and decreases the increased autophagy observed in rats with type 2 diabetic nephropathy. In this study, 24-week-old Goto-Kakizaki male rats were randomly divided into groups that received either a normal protein diet (NPD group), a low-protein diet (LPD group) or a low-protein diet supplemented with ketoacids (LPD+KA group) for 24 weeks. Age- and weight-matched Wistar rats served as control animals and received a normal protein diet (control group). We found that protein restriction attenuated proteinuria and decreased blood urea nitrogen and serum creatinine levels. Compared with the NPD and LPD groups, the LPD+KA group showed a delay in body weight loss, an attenuation in soleus muscle mass loss and a decrease of the mean cross-sectional area of soleus muscle fibers. The mRNA and protein expression of autophagy-related genes, such as Beclin-1, LC3B, Bnip3, p62 and Cathepsin L, were increased in the soleus muscle of GK rats fed with NPD compared to Wistar rats. Importantly, LPD resulted in a slight reduction in the expression of autophagy-related genes; however, these differences were not statistically significant. In addition, LPD+KA abolished the upregulation of autophagy-related gene expression. Furthermore, the activation of autophagy in the NPD and LPD groups was confirmed by the appearance of autophagosomes or autolysosomes using electron microscopy, when compared with the Control and LPD+KA groups. Our results showed that LPD+KA abolished the activation of autophagy in skeletal muscle and decreased muscle loss in rats with type 2 diabetic nephropathy.
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Affiliation(s)
- Juan Huang
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Jialin Wang
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Lijie Gu
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Jinfang Bao
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Jun Yin
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Zhihuan Tang
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Ling Wang
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Weijie Yuan
- Department of Nephrology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
- * E-mail:
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Leucine and HMB differentially modulate proteasome system in skeletal muscle under different sarcopenic conditions. PLoS One 2013; 8:e76752. [PMID: 24124592 PMCID: PMC3790739 DOI: 10.1371/journal.pone.0076752] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 08/29/2013] [Indexed: 12/23/2022] Open
Abstract
In the present study we have compared the effects of leucine supplementation and its metabolite β-hydroxy-β-methyl butyrate (HMB) on the ubiquitin-proteasome system and the PI3K/Akt pathway during two distinct atrophic conditions, hindlimb immobilization and dexamethasone treatment. Leucine supplementation was able to minimize the reduction in rat soleus mass driven by immobilization. On the other hand, leucine supplementation was unable to provide protection against soleus mass loss in dexamethasone treated rats. Interestingly, HMB supplementation was unable to provide protection against mass loss in all treatments. While solely fiber type I cross sectional area (CSA) was protected in immobilized soleus of leucine-supplemented rats, none of the fiber types were protected by leucine supplementation in rats under dexamethasone treatment. In addition and in line with muscle mass results, HMB treatment did not attenuate CSA decrease in all fiber types against either immobilization or dexamethasone treatment. While leucine supplementation was able to minimize increased expression of both Mafbx/Atrogin and MuRF1 in immobilized rats, leucine was only able to minimize Mafbx/Atrogin in dexamethasone treated rats. In contrast, HMB was unable to restrain the increase in those atrogenes in immobilized rats, but in dexamethasone treated rats, HMB minimized increased expression of Mafbx/Atrogin. The amount of ubiquitinated proteins, as expected, was increased in immobilized and dexamethasone treated rats and only leucine was able to block this increase in immobilized rats but not in dexamethasone treated rats. Leucine supplementation maintained soleus tetanic peak force in immobilized rats at normal level. On the other hand, HMB treatment failed to maintain tetanic peak force regardless of treatment. The present data suggested that the anti-atrophic effects of leucine are not mediated by its metabolite HMB.
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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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McIntire KL, Chen Y, Sood S, Rabkin R. Acute uremia suppresses leucine-induced signal transduction in skeletal muscle. Kidney Int 2013; 85:374-82. [PMID: 23783244 DOI: 10.1038/ki.2013.216] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 04/02/2013] [Accepted: 04/11/2013] [Indexed: 12/30/2022]
Abstract
Adequate nutrient intake in acute uremia is a key part of patient management especially as food utilization is usually impaired. Leucine is important as it comprises about one-fifth of essential amino acid needs and, apart from serving as a substrate, it directly activates the mTOR signaling pathway stimulating protein synthesis and inhibiting autophagy. Here we tested whether leucine activation of the mTOR signaling pathway in muscle is severely disrupted in acute uremia. Several abnormalities were identified in bilateral ureteral ligated (model of acute uremia) compared to sham-operated pair-fed control rats. Levels of several signaling proteins increased significantly while leucine-induced phosphorylation of mTOR and downstream proteins, 4e-BP1 and S6K1, was completely suppressed. Levels of LC3B-II, a specific autophagosomal membrane-associated protein used as a marker of autophagy, increased threefold in uremia. Furthermore, while leucine suppressed LC3B-II levels in controls, it failed to do so in uremic rats. Muscle IL-6 mRNA levels increased, while IGF-1 mRNA levels decreased in uremia. These findings establish that, in acute uremia, severe resistance to leucine-induced activation of the mTOR anabolic signaling pathway develops. Thus, leucine resistance, together with the reduction in IGF-1 and increase in IL-6 expression, may explain why the anabolic effect of nutritional therapy is diminished in acute uremic patients.
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Affiliation(s)
- Kevin L McIntire
- 1] Research Service, Veterans Affairs Palo Alto Health Care System (VAPAHCS), Palo Alto, California, USA [2] Renal Division, Department of Medicine, Stanford University, Stanford, California, USA
| | - Yu Chen
- 1] Research Service, Veterans Affairs Palo Alto Health Care System (VAPAHCS), Palo Alto, California, USA [2] Renal Division, Department of Medicine, Stanford University, Stanford, California, USA
| | - Sumita Sood
- 1] Research Service, Veterans Affairs Palo Alto Health Care System (VAPAHCS), Palo Alto, California, USA [2] Renal Division, Department of Medicine, Stanford University, Stanford, California, USA
| | - Ralph Rabkin
- 1] Research Service, Veterans Affairs Palo Alto Health Care System (VAPAHCS), Palo Alto, California, USA [2] Renal Division, Department of Medicine, Stanford University, Stanford, California, USA
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Stimulation of rat liver branched-chain alpha-keto acid dehydrogenase activity by low doses of bezafibrate. Toxicology 2013; 306:101-7. [PMID: 23485652 DOI: 10.1016/j.tox.2013.02.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/25/2013] [Accepted: 02/12/2013] [Indexed: 11/22/2022]
Abstract
Multienzyme branched-chain alpha-ketoacid dehydrogenase complex (BCKDH) catalyzes the regulatory step of oxidative catabolism of indispensable branched-chain amino acids (BCAA). The activity of the BCKDH complex is regulated by a reversible phosphorylation, end-product inhibition and by changes in the gene expression of BCKDH component enzymes. It has been shown previously that a high dose of bezafibrate (an agent added to rat chow at final concentration of 0.5%) changes mRNA levels of BCKDH-related enzymes and increases dephosphorylation of the complex leading to stimulation of liver BCKDH activity and the enhanced BCAA catabolism. The aim of the present study was to determine an in vivo effect of low, clinically relevant doses of bezafibrate on BCKDH activity in rat liver. Bezafibrate was administrated for 14 days by gastric gavage to Wistar male rats (fed low-protein chow; 8% protein) at one of the following daily doses of 5, 10 and 20mg/kgb.wt. The control group was given the vehicle (0.3% methylcellulose) only. The actual BCKDH and total BCKDH activities were assayed spectrophotometrically before and after incubation with a broad-specificity phosphatase, respectively. The mRNA levels of the selected genes (BCKDH catalytic subunits and regulatory enzymes) were quantified by means of semi-quantitative RT-PCR. Current catalytic activity of BCKDH (described as BCKDH activity state - the proportion of the BCKDH complex in its active dephosphorylated form) increased by 2.1 ± 0.2, 2.3 ± 0.2 and 2.7 ± 0.2 fold (p<0.01). Changes in BCKDH activity did not correspond with changes in mRNA levels of the complex catalytic subunits. Moreover, mRNA levels of regulatory enzymes remained unaltered. Initially bezafibrate caused a transient insignificant reduction in body weight, but it had no effect on the final body weight. The highest dose of bezafibrate induced hepatomegaly. In conclusion, these data indicate that under conditions of dietary protein restriction low, clinically relevant doses of bezafibrate have a similar adverse effect on rat liver BCKDH activity and BCAA degradation rate as the high experimental dose. Up-regulation of liver BCKDH activity by low doses of bezafibrate appears to result mainly from changes in phosphorylation status of the complex (increased dephosphorylation) and is not associated with elevations in mRNA levels of BCKDH enzymatic components.
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Leptin and leucine synergistically regulate protein metabolism in C2C12 myotubes and mouse skeletal muscles. Br J Nutr 2012; 110:256-64. [PMID: 23211060 DOI: 10.1017/s0007114512004849] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Leucine and leptin play important roles in regulating protein synthesis and degradation in skeletal muscles in vitro and in vivo. However, the objective of the present study was to determine whether leptin and leucine function synergistically in regulating protein metabolism of skeletal muscles. In the in vitro experiment, C2C12 myotubes were cultured for 2 h in the presence of 5 mm-leucine and/or 50 ng/ml of leptin. In the in vivo experiment, C57BL/6 and ob/ob mice were randomly assigned to be fed a non-purified diet supplemented with 3 % L-leucine or 2·04 % L-alanine (isonitrogenous control) for 14 d. Ob/ob mice were injected intraperitoneally with sterile PBS or recombinant mouse leptin (0·1 μg/g body weight) for 14 d. In C57BL/6 mice, dietary leucine supplementation increased (P< 0·05) plasma leptin, leptin receptor expression and protein synthesis in skeletal muscles, but reduced (P< 0·05) plasma urea and protein degradation in skeletal muscles. Dietary leucine supplementation and leptin injection increased the relative weight of the gastrocnemius and soleus muscles in ob/ob mice. Moreover, leucine and leptin treatments stimulated (P< 0·05) protein synthesis and inhibited (P< 0·05) protein degradation in C2C12 myotubes and skeletal muscles of ob/ob mice. There were interactions (P< 0·05) between the leucine and leptin treatments with regard to protein metabolism in C2C12 myotubes and soleus muscles of ob/ob mice but not in the gastrocnemius muscles of ob/ob mice. Collectively, these results suggest that leptin and leucine synergistically regulate protein metabolism in skeletal muscles both in vitro and in vivo.
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Maki T, Yamamoto D, Nakanishi S, Iida K, Iguchi G, Takahashi Y, Kaji H, Chihara K, Okimura Y. Branched-chain amino acids reduce hindlimb suspension-induced muscle atrophy and protein levels of atrogin-1 and MuRF1 in rats. Nutr Res 2012; 32:676-83. [PMID: 23084640 DOI: 10.1016/j.nutres.2012.07.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 07/13/2012] [Accepted: 07/18/2012] [Indexed: 12/19/2022]
Abstract
Atrogin-1 and MuRF1, muscle-specific ubiquitin ligases, and autophagy play a role in protein degradation in muscles. We hypothesized that branched-chain amino acids (BCAAs) may decrease atrogin-1, MuRF1, and autophagy, and may have a protective effect on disuse muscle atrophy. To test this hypothesis, we selected hindlimb suspension (HS)-induced muscle atrophy as a model of disuse muscle atrophy because it is an established model to investigate the effects of decreased muscle activity. Sprague-Dawley male rats were assigned to 4 groups: control, HS (14 days), oral BCAA administration (600 mg/[kg day], 22.9% L-isoleucine, 45.8% L-leucine, and 27.6% L-valine), and HS and BCAA administration. After 14 days of the treatment, muscle weights and protein concentrations, cross-sectional area (CSA) of the muscle fibers, atrogin-1 and MuRF1 proteins, and microtubule-associated protein 1 light chain 3 II/I (ratio of LC3 II/I) were measured. Hindlimb suspension significantly reduced soleus muscle weight and CSA of the muscle fibers. Branched-chain amino acid administration partly but significantly reversed the HS-induced decrease in CSA. Hindlimb suspension increased atrogin-1 and MuRF1 proteins, which play a pivotal role in various muscle atrophies. Branched-chain amino acid attenuated the increase in atrogin-1 and MuRF1 in soleus muscles. Hindlimb suspension significantly increased the ratio of LC3 II/I, an indicator of autophagy, whereas BCAA did not attenuate the increase in the ratio of LC3 II/I. These results indicate the possibility that BCAA inhibits HS-induced muscle atrophy, at least in part, via the inhibition of the ubiquitin-proteasome pathway. Oral BCAA administration appears to have the potential to prevent disuse muscle atrophy.
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Affiliation(s)
- Taiki Maki
- Department of Biophysics, Kobe University Graduate School of Health Science, Kobe, Japan
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Abstract
Recent advances in elucidating the mechanisms that control body protein synthesis and degradation both expand and complicate our understanding of how these processes are regulated. This review presents an introduction to the multiple regulatory systems involved, emphasizing the number of potential controls. These include gene transcription, gene activation or suppression, activation or suppression of mRNA translation and activation or suppression of signaling pathways. The complexity of these interacting controls presents a challenge to our understanding of the overall coordinated regulation of protein synthesis and degradation and its response to any particular stimulus. Specific examples are used to illustrate regulatory mechanisms, including the ways in which protein metabolism is regulated by the amino acid leucine. In addition to regulation associated with gene expression and post-translational control, the expanding field of epigenetics adds another layer of complexity, including trans-generational responses to nutrient intake, highlighting the potential for long-term impact of nutritional experience on the metabolism of subsequent generations.
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Borgenvik M, Apró W, Blomstrand E. Intake of branched-chain amino acids influences the levels of MAFbx mRNA and MuRF-1 total protein in resting and exercising human muscle. Am J Physiol Endocrinol Metab 2012; 302:E510-21. [PMID: 22127230 DOI: 10.1152/ajpendo.00353.2011] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Resistance exercise and amino acids are two major factors that influence muscle protein turnover. Here, we examined the effects of resistance exercise and branched-chain amino acids (BCAA), individually and in combination, on the expression of anabolic and catabolic genes in human skeletal muscle. Seven subjects performed two sessions of unilateral leg press exercise with randomized supplementation with BCAA or flavored water. Biopsies were collected from the vastus lateralis muscle of both the resting and exercising legs before and repeatedly after exercise to determine levels of mRNA, protein phosphorylation, and amino acid concentrations. Intake of BCAA reduced (P < 0.05) MAFbx mRNA by 30 and 50% in the resting and exercising legs, respectively. The level of MuRF-1 mRNA was elevated (P < 0.05) in the exercising leg two- and threefold under the placebo and BCAA conditions, respectively, whereas MuRF-1 total protein increased by 20% (P < 0.05) only in the placebo condition. Phosphorylation of p70(S6k) increased to a larger extent (∼2-fold; P < 0.05) in the early recovery period with BCAA supplementation, whereas the expression of genes regulating mTOR activity was not influenced by BCAA. Muscle levels of phenylalanine and tyrosine were reduced (13-17%) throughout recovery (P < 0.05) in the placebo condition and to a greater extent (32-43%; P < 0.05) following BCAA supplementation in both resting and exercising muscle. In conclusion, BCAA ingestion reduced MAFbx mRNA and prevented the exercise-induced increase in MuRF-1 total protein in both resting and exercising leg. Further-more, resistance exercise differently influenced MAFbx and MuRF-1 mRNA expression, suggesting both common and divergent regulation of these two ubiquitin ligases.
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Affiliation(s)
- Marcus Borgenvik
- The Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
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Davoodi J, Markert CD, Voelker KA, Hutson SM, Grange RW. Nutrition strategies to improve physical capabilities in Duchenne muscular dystrophy. Phys Med Rehabil Clin N Am 2011; 23:187-99, xii-xiii. [PMID: 22239883 DOI: 10.1016/j.pmr.2011.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
There is no current cure for Duchenne muscular dystrophy (DMD), and palliative and prophylactic interventions to improve the quality of life of patients remain limited, with the exception of corticosteroids. This article describes 2 potential nutritional interventions for the treatment of DMD, green tea extract (GTE) and the branched-chain amino acid leucine, and their positive effects on physical activity. Both GTE and leucine are suitable for human consumption, are easily tolerated with no side effects, and, with appropriate preclinical data, could be brought forward to clinical trials rapidly.
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Affiliation(s)
- J Davoodi
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
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Glynn EL, Fry CS, Drummond MJ, Timmerman KL, Dhanani S, Volpi E, Rasmussen BB. Excess leucine intake enhances muscle anabolic signaling but not net protein anabolism in young men and women. J Nutr 2010; 140:1970-6. [PMID: 20844186 PMCID: PMC2955876 DOI: 10.3945/jn.110.127647] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Essential amino acids (EAA) stimulate skeletal muscle protein synthesis (MPS) in humans. Leucine may have a greater stimulatory effect on MPS than other EAA and/or decrease muscle protein breakdown (MPB). To determine the effect of 2 different leucine concentrations on muscle protein turnover and associated signaling, young men (n = 6) and women (n = 8) ingested 10 g EAA in 1 of 2 groups: composition typical of high quality proteins (CTRL; 1.8 g leucine) or increased leucine concentration (LEU; 3.5 g leucine). Participants were studied for 180 min postingestion. Fractional synthetic rate and leg phenylalanine and leucine kinetics were assessed on muscle biopsies using stable isotopic techniques. Signaling was determined by immunoblotting. Arterial leucine concentration and delivery to the leg increased in both groups and was significantly higher in LEU than in CTRL; however, transport into the muscle and intracellular availability did not differ between groups. MPS increased similarly in both groups 60 min postingestion. MPB decreased at 60 min only in LEU, but net muscle protein balance improved similarly. Components of mammalian target of rapamycin (mTOR) signaling were improved in LEU, but no changes were observed in ubiquitin-proteasome system signaling. Changes in light chain 3 and mTOR association with Unc-51-like kinase 1 indicate autophagy decreased more in LEU. We conclude that in 10 g of EAA, the leucine content typical of high quality proteins (~1.8 g) is sufficient to induce a maximal skeletal muscle protein anabolic response in young adults, but leucine may play a role in autophagy regulation.
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Affiliation(s)
- Erin L. Glynn
- Departments of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX 77555
| | - Christopher S. Fry
- Departments of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX 77555
| | - Micah J. Drummond
- Departments of Physical Therapy, University of Texas Medical Branch, Galveston, TX 77555,Departments of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX 77555,Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX 77555
| | - Kyle L. Timmerman
- Departments of Internal Medicine, Divisions of University of Texas Medical Branch, Galveston, TX 77555
| | - Shaheen Dhanani
- Departments of Internal Medicine, Divisions of University of Texas Medical Branch, Galveston, TX 77555
| | - Elena Volpi
- Departments of Internal Medicine, Divisions of University of Texas Medical Branch, Galveston, TX 77555,Departments of Geriatrics, University of Texas Medical Branch, Galveston, TX 77555
| | - Blake B. Rasmussen
- Departments of Physical Therapy, University of Texas Medical Branch, Galveston, TX 77555,Departments of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX 77555,Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX 77555,To whom correspondence should be addressed. E-mail:
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Grumati P, Coletto L, Sabatelli P, Cescon M, Angelin A, Bertaggia E, Blaauw B, Urciuolo A, Tiepolo T, Merlini L, Maraldi NM, Bernardi P, Sandri M, Bonaldo P. Autophagy is defective in collagen VI muscular dystrophies, and its reactivation rescues myofiber degeneration. Nat Med 2010; 16:1313-20. [DOI: 10.1038/nm.2247] [Citation(s) in RCA: 407] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 09/24/2010] [Indexed: 02/07/2023]
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50
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Bonetto A, Penna F, Minero VG, Reffo P, Costamagna D, Bonelli G, Baccino FM, Costelli P. Glutamine prevents myostatin hyperexpression and protein hypercatabolism induced in C2C12 myotubes by tumor necrosis factor-α. Amino Acids 2010; 40:585-94. [DOI: 10.1007/s00726-010-0683-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 06/29/2010] [Indexed: 01/13/2023]
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