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Fatoki TH, Chukwuejim S, Udenigwe CC, Aluko RE. In Silico Exploration of Metabolically Active Peptides as Potential Therapeutic Agents against Amyotrophic Lateral Sclerosis. Int J Mol Sci 2023; 24:ijms24065828. [PMID: 36982902 PMCID: PMC10058213 DOI: 10.3390/ijms24065828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/11/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is regarded as a fatal neurodegenerative disease that is featured by progressive damage of the upper and lower motor neurons. To date, over 45 genes have been found to be connected with ALS pathology. The aim of this work was to computationally identify unique sets of protein hydrolysate peptides that could serve as therapeutic agents against ALS. Computational methods which include target prediction, protein-protein interaction, and peptide-protein molecular docking were used. The results showed that the network of critical ALS-associated genes consists of ATG16L2, SCFD1, VAC15, VEGFA, KEAP1, KIF5A, FIG4, TUBA4A, SIGMAR1, SETX, ANXA11, HNRNPL, NEK1, C9orf72, VCP, RPSA, ATP5B, and SOD1 together with predicted kinases such as AKT1, CDK4, DNAPK, MAPK14, and ERK2 in addition to transcription factors such as MYC, RELA, ZMIZ1, EGR1, TRIM28, and FOXA2. The identified molecular targets of the peptides that support multi-metabolic components in ALS pathogenesis include cyclooxygenase-2, angiotensin I-converting enzyme, dipeptidyl peptidase IV, X-linked inhibitor of apoptosis protein 3, and endothelin receptor ET-A. Overall, the results showed that AGL, APL, AVK, IIW, PVI, and VAY peptides are promising candidates for further study. Future work would be needed to validate the therapeutic properties of these hydrolysate peptides by in vitro and in vivo approaches.
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Affiliation(s)
| | - Stanley Chukwuejim
- Department of Biochemistry, Federal University Oye-Ekiti, PMB 373, Oye 371104, Nigeria
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Chibuike C Udenigwe
- Faculty of Health Sciences, School of Nutrition Sciences, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Department of Chemistry and Biomolecular Sciences, Faculty of Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Rotimi E Aluko
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Richardson Centre for Food Technology and Research, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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Vinci P, Di Girolamo FG, Mangogna A, Mearelli F, Nunnari A, Fiotti N, Giordano M, Bareille MP, Biolo G. Early lean mass sparing effect of high-protein diet with excess leucine during long-term bed rest in women. Front Nutr 2022; 9:976818. [PMID: 36505255 PMCID: PMC9729546 DOI: 10.3389/fnut.2022.976818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 11/09/2022] [Indexed: 11/25/2022] Open
Abstract
Muscle inactivity leads to muscle atrophy. Leucine is known to inhibit protein degradation and to promote protein synthesis in skeletal muscle. We tested the ability of a high-protein diet enriched with branched-chain amino acids (BCAAs) to prevent muscle atrophy during long-term bed rest (BR). We determined body composition (using dual energy x-ray absorptiometry) at baseline and every 2-weeks during 60 days of BR in 16 healthy young women. Nitrogen (N) balance was assessed daily as the difference between N intake and N urinary excretion. The subjects were randomized into two groups: one received a conventional diet (1.1 ± 0.03 g protein/kg, 4.9 ± 0.3 g leucine per day) and the other a high protein, BCAA-enriched regimen (1.6 ± 0.03 g protein-amino acid/kg, 11.4 ± 0.6 g leucine per day). There were significant BR and BR × diet interaction effects on changes in lean body mass (LBM) and N balance throughout the experimental period (repeated measures ANCOVA). During the first 15 days of BR, lean mass decreased by 4.1 ± 0.9 and 2.4 ± 2.1% (p < 0.05) in the conventional and high protein-BCAA diet groups, respectively, while at the end of the 60-day BR, LBM decreased similarly in the two groups by 7.4 ± 0.7 and 6.8 ± 2.4%. During the first 15 days of BR, mean N balance was 2.5 times greater (p < 0.05) in subjects on the high protein-BCAA diet than in those on the conventional diet, while we did not find significant differences during the following time intervals. In conclusion, during 60 days of BR in females, a high protein-BCAA diet was associated with an early protein-LBM sparing effect, which ceased in the medium and long term.
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Affiliation(s)
- Pierandrea Vinci
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Filippo Giorgio Di Girolamo
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy,Hospital Pharmacy, Cattinara Hospital, Azienda Sanitaria Universitaria Giuliano Isontina, Trieste, Italy
| | - Alessandro Mangogna
- Institute for Maternal and Child Health, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Burlo Garofolo, Trieste, Italy
| | - Filippo Mearelli
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Alessio Nunnari
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Nicola Fiotti
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy
| | - Mauro Giordano
- Department of Advanced Medical and Surgical Sciences, University of Campania L. Vanvitelli, Naples, Italy
| | | | - Gianni Biolo
- Department of Medical Surgical and Health Sciences, Medical Clinic, Cattinara Hospital, University of Trieste, Trieste, Italy,*Correspondence: Gianni Biolo,
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Petrocelli JJ, Drummond MJ. PGC-1α-Targeted Therapeutic Approaches to Enhance Muscle Recovery in Aging. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17228650. [PMID: 33233350 PMCID: PMC7700690 DOI: 10.3390/ijerph17228650] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/12/2022]
Abstract
Impaired muscle recovery (size and strength) following a disuse period commonly occurs in older adults. Many of these individuals are not able to adequately exercise due to pain and logistic barriers. Thus, nutritional and pharmacological therapeutics, that are translatable, are needed to promote muscle recovery following disuse in older individuals. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be a suitable therapeutic target due to pleiotropic regulation of skeletal muscle. This review focuses on nutritional and pharmacological interventions that target PGC-1α and related Sirtuin 1 (SIRT1) and 5' AMP-activated protein kinase (AMPKα) signaling in muscle and thus may be rapidly translated to prevent muscle disuse atrophy and promote recovery. In this review, we present several therapeutics that target PGC-1α in skeletal muscle such as leucine, β-hydroxy-β-methylbuyrate (HMB), arginine, resveratrol, metformin and combination therapies that may have future application to conditions of disuse and recovery in humans.
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Koike TE, Watanabe AY, Kodama FY, Ozaki GAT, Castoldi RC, Garcia TA, Camargo RCT, Camargo Filho JCS. PHYSICAL EXERCISE AFTER IMMOBILIZATION OF SKELETAL MUSCLE OF ADULT AND AGED RATS. REV BRAS MED ESPORTE 2018. [DOI: 10.1590/1517-869220182401172423] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
ABSTRACT Introduction: Immobilization is a treatment technique often used to reduce pain and prevent worsening of the injury. However, it promotes harmful effects on musculoskeletal tissue, resulting in a marked loss of muscle function, which may be aggravated in the elderly. Physical exercise is an important intervention to mitigate these harmful effects. Objective: To analyze possible morphometric changes in the gastrocnemius muscle of rats after immobilization and remobilization with physical exercise. Methods: Fifty-six rats were divided into adult (A) and aged (E) groups and subdivided into adult and aged control (AC and EC), immobilized (AI and EI), free remobilized (AIF and EIF), and remobilized through physical exercise (AIE and EIE). The hind limbs were immobilized with the gastrocnemius muscle in a shortened position for a period of seven days, except for the control group. The exercise protocol consisted of five swimming sessions, once per day (25 minutes/session). The animals were euthanized by administration of an overdose of ketamine hydrochloride plus xylazine hydrochloride, followed by sample collection and preparation of hematoxylin and eosin slides. Measurements of the smallest diameter of 120 muscle fibers of each animal were taken with software NIS-Elements D3.0 - SP7 - Nikon® instruments Inc., NY, USA. Results: There was a significant reduction in the mean fiber diameter in the AI (38.43 µm ± 4.20; p=0.01) and AIF (36.97 µm ± 3.41; p<0.01) groups compared to AC (45.39 µm ± 3.41) and in the EI (42.26 µm ± 4.39; p<0.01), EIF (36.00 µm ± 4.15; p<0.01), and EIE (41.86 µm ± 4.95; p<0.01) groups compared to the EC (51.37 µm ± 3.86) group. The data showed that exercise was able to restore muscle trophism in the adult groups; however, none of the protocols has succeeded in aged rats. Conclusion: Immobilization in the shortened position induced muscle atrophy and physical exercise was effective in restoring muscular trophism only in adult animals. Level of Evidence I; Therapeutic studies - Investigating the Results of Treatment.
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Affiliation(s)
- Tatiana Emy Koike
- Universidade Estadual de São Paulo “Julio de Mesquita Filho”, Brazil
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Marzuca-Nassr GN, Murata GM, Martins AR, Vitzel KF, Crisma AR, Torres RP, Mancini-Filho J, Kang JX, Curi R. Balanced Diet-Fed Fat-1 Transgenic Mice Exhibit Lower Hindlimb Suspension-Induced Soleus Muscle Atrophy. Nutrients 2017; 9:nu9101100. [PMID: 28984836 PMCID: PMC5691716 DOI: 10.3390/nu9101100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/16/2017] [Accepted: 09/22/2017] [Indexed: 12/17/2022] Open
Abstract
The consequences of two-week hindlimb suspension (HS) on skeletal muscle atrophy were investigated in balanced diet-fed Fat-1 transgenic and C57BL/6 wild-type mice. Body composition and gastrocnemius fatty acid composition were measured. Skeletal muscle force, cross-sectional area (CSA), and signaling pathways associated with protein synthesis (protein kinase B, Akt; ribosomal protein S6, S6, eukaryotic translation initiation factor 4E-binding protein 1, 4EBP1; glycogen synthase kinase3-beta, GSK3-beta; and extracellular-signal-regulated kinases 1/2, ERK 1/2) and protein degradation (atrophy gene-1/muscle atrophy F-box, atrogin-1/MAFbx and muscle RING finger 1, MuRF1) were evaluated in the soleus muscle. HS decreased soleus muscle wet and dry weights (by 43% and 26%, respectively), muscle isotonic and tetanic force (by 29% and 18%, respectively), CSA of the soleus muscle (by 36%), and soleus muscle fibers (by 45%). Fat-1 transgenic mice had a decrease in the ω-6/ω-3 polyunsaturated fatty acids (PUFAs) ratio as compared with C57BL/6 wild-type mice (56%, p < 0.001). Fat-1 mice had lower soleus muscle dry mass loss (by 10%) and preserved absolute isotonic force (by 17%) and CSA of the soleus muscle (by 28%) after HS as compared with C57BL/6 wild-type mice. p-GSK3B/GSK3B ratio was increased (by 70%) and MuRF-1 content decreased (by 50%) in the soleus muscle of Fat-1 mice after HS. Balanced diet-fed Fat-1 mice are able to preserve in part the soleus muscle mass, absolute isotonic force and CSA of the soleus muscle in a disuse condition.
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Affiliation(s)
- Gabriel Nasri Marzuca-Nassr
- Department of Internal Medicine, Faculty of Medicine, Universidad de La Frontera, Temuco 4780000, Chile.
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Gilson Masahiro Murata
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Amanda Roque Martins
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Kaio Fernando Vitzel
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
- School of Health Sciences, College of Health, Massey University, Auckland 0632, New Zealand.
| | - Amanda Rabello Crisma
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Rosângela Pavan Torres
- Laboratory of Lipids, Department of Food Science and Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Jorge Mancini-Filho
- Laboratory of Lipids, Department of Food Science and Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Jing Xuan Kang
- Laboratory for Lipid Medicine and Technology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Rui Curi
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
- Interdisciplinary Post-Graduate Program in Health Sciences, Cruzeiro do Sul University, São Paulo, Brazil.
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Booth FW, Roberts CK, Thyfault JP, Ruegsegger GN, Toedebusch RG. Role of Inactivity in Chronic Diseases: Evolutionary Insight and Pathophysiological Mechanisms. Physiol Rev 2017; 97:1351-1402. [PMID: 28814614 PMCID: PMC6347102 DOI: 10.1152/physrev.00019.2016] [Citation(s) in RCA: 329] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 12/13/2022] Open
Abstract
This review proposes that physical inactivity could be considered a behavior selected by evolution for resting, and also selected to be reinforcing in life-threatening situations in which exercise would be dangerous. Underlying the notion are human twin studies and animal selective breeding studies, both of which provide indirect evidence for the existence of genes for physical inactivity. Approximately 86% of the 325 million in the United States (U.S.) population achieve less than the U.S. Government and World Health Organization guidelines for daily physical activity for health. Although underappreciated, physical inactivity is an actual contributing cause to at least 35 unhealthy conditions, including the majority of the 10 leading causes of death in the U.S. First, we introduce nine physical inactivity-related themes. Next, characteristics and models of physical inactivity are presented. Following next are individual examples of phenotypes, organ systems, and diseases that are impacted by physical inactivity, including behavior, central nervous system, cardiorespiratory fitness, metabolism, adipose tissue, skeletal muscle, bone, immunity, digestion, and cancer. Importantly, physical inactivity, itself, often plays an independent role as a direct cause of speeding the losses of cardiovascular and strength fitness, shortening of healthspan, and lowering of the age for the onset of the first chronic disease, which in turn decreases quality of life, increases health care costs, and accelerates mortality risk.
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Affiliation(s)
- Frank W Booth
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Geriatrics, Research, Education and Clinical Center (GRECC), VA Greater Los Angeles Healthcare System, Los Angeles, California; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; and Cardiovascular Division, Department of Medicine, University of Missouri, Columbia, Missouri
| | - Christian K Roberts
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Geriatrics, Research, Education and Clinical Center (GRECC), VA Greater Los Angeles Healthcare System, Los Angeles, California; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; and Cardiovascular Division, Department of Medicine, University of Missouri, Columbia, Missouri
| | - John P Thyfault
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Geriatrics, Research, Education and Clinical Center (GRECC), VA Greater Los Angeles Healthcare System, Los Angeles, California; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; and Cardiovascular Division, Department of Medicine, University of Missouri, Columbia, Missouri
| | - Gregory N Ruegsegger
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Geriatrics, Research, Education and Clinical Center (GRECC), VA Greater Los Angeles Healthcare System, Los Angeles, California; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; and Cardiovascular Division, Department of Medicine, University of Missouri, Columbia, Missouri
| | - Ryan G Toedebusch
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Geriatrics, Research, Education and Clinical Center (GRECC), VA Greater Los Angeles Healthcare System, Los Angeles, California; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas; and Cardiovascular Division, Department of Medicine, University of Missouri, Columbia, Missouri
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Cannavino J, Brocca L, Sandri M, Bottinelli R, Pellegrino MA. PGC1-α over-expression prevents metabolic alterations and soleus muscle atrophy in hindlimb unloaded mice. J Physiol 2014; 592:4575-89. [PMID: 25128574 DOI: 10.1113/jphysiol.2014.275545] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Prolonged skeletal muscle inactivity causes muscle fibre atrophy. Redox imbalance has been considered one of the major triggers of skeletal muscle disuse atrophy, but whether redox imbalance is actually the major cause or simply a consequence of muscle disuse remains of debate. Here we hypothesized that a metabolic stress mediated by PGC-1α down-regulation plays a major role in disuse atrophy. First we studied the adaptations of soleus to mice hindlimb unloading (HU) in the early phase of disuse (3 and 7 days of HU) with and without antioxidant treatment (trolox). HU caused a reduction in cross-sectional area, redox status alteration (NRF2, SOD1 and catalase up-regulation), and induction of the ubiquitin proteasome system (MuRF-1 and atrogin-1 mRNA up-regulation) and autophagy (Beclin1 and p62 mRNA up-regulation). Trolox completely prevented the induction of NRF2, SOD1 and catalase mRNAs, but not atrophy or induction of catabolic systems in unloaded muscles, suggesting that oxidative stress is not a major cause of disuse atrophy. HU mice showed a marked alteration of oxidative metabolism. PGC-1α and mitochondrial complexes were down-regulated and DRP1 was up-regulated. To define the link between mitochondrial dysfunction and disuse muscle atrophy we unloaded mice overexpressing PGC-1α. Transgenic PGC-1α animals did not show metabolic alteration during unloading, preserving muscle size through the reduction of autophagy and proteasome degradation. Our results indicate that mitochondrial dysfunction plays a major role in disuse atrophy and that compounds inducing PGC-1α expression could be useful to treat/prevent muscle atrophy.
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Affiliation(s)
- Jessica Cannavino
- Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy
| | - Lorenza Brocca
- Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy
| | - Marco Sandri
- Venetian Institute of Molecular Medicine and Dulbecco Telethon Institute, 35129, Padova, Italy Interuniversity Institute of Myology, University of Pavia, Pavia, Italy
| | - Roberto Bottinelli
- Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy Fondazione Salvatore Maugeri (IRCCS), Scientific Institute of Pavia, Pavia, Italy Interdipartimental Centre for Biology and Sport Medicine, University of Pavia, Pavia, Italy
| | - Maria Antonietta Pellegrino
- Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy Interuniversity Institute of Myology, University of Pavia, Pavia, Italy Interdipartimental Centre for Biology and Sport Medicine, University of Pavia, Pavia, Italy
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Dirks ML, Wall BT, Nilwik R, Weerts DHJM, Verdijk LB, van Loon LJC. Skeletal muscle disuse atrophy is not attenuated by dietary protein supplementation in healthy older men. J Nutr 2014; 144:1196-203. [PMID: 24919692 DOI: 10.3945/jn.114.194217] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Short successive periods of muscle disuse, due to injury or illness, can contribute significantly to the loss of muscle mass with aging (sarcopenia). It has been suggested that increasing the protein content of the diet may be an effective dietary strategy to attenuate muscle disuse atrophy. We hypothesized that protein supplementation twice daily would preserve muscle mass during a short period of limb immobilization. Twenty-three healthy older (69 ± 1 y) men were subjected to 5 d of one-legged knee immobilization by means of a full-leg cast with (PRO group; n = 11) or without (CON group; n = 12) administration of a dietary protein supplement (20.7 g of protein, 9.3 g of carbohydrate, and 3.0 g of fat) twice daily. Two d prior to and immediately after the immobilization period, single-slice computed tomography scans of the quadriceps and single-leg 1 repetition maximum strength tests were performed to assess muscle cross-sectional area (CSA) and leg muscle strength, respectively. Additionally, muscle biopsies were collected to assess muscle fiber characteristics as well as mRNA and protein expression of selected genes. Immobilization decreased quadriceps' CSAs by 1.5 ± 0.7% (P < 0.05) and 2.0 ± 0.6% (P < 0.05), and muscle strength by 8.3 ± 3.3% (P < 0.05) and 9.3 ± 1.6% (P < 0.05) in the CON and PRO groups, respectively, without differences between groups. Skeletal muscle myostatin, myogenin, and muscle RING-finger protein-1 (MuRF1) mRNA expression increased following immobilization in both groups (P < 0.05), whereas muscle atrophy F-box/atrogen-1 (MAFBx) mRNA expression increased in the PRO group only (P < 0.05). In conclusion, dietary protein supplementation (∼20 g twice daily) does not attenuate muscle loss during short-term muscle disuse in healthy older men. This trial was registered at clinicaltrials.gov as NCT01588808.
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Affiliation(s)
- Marlou L Dirks
- NUTRIM School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, The Netherlands; and
| | - Benjamin T Wall
- NUTRIM School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, The Netherlands; and
| | - Rachel Nilwik
- NUTRIM School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, The Netherlands; and
| | - Daniëlle H J M Weerts
- NUTRIM School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, The Netherlands; and
| | - Lex B Verdijk
- NUTRIM School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, The Netherlands; and
| | - Luc J C van Loon
- NUTRIM School for Nutrition, Toxicology, and Metabolism, Maastricht University, Maastricht, The Netherlands; and
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