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Hwangbo H, Kim MY, Ji SY, Kim DH, Park BS, Jeong SU, Yoon JH, Kim TH, Kim GY, Choi YH. A Mixture of Morus alba and Angelica keiskei Leaf Extracts Improves Muscle Atrophy by Activating the PI3K/Akt/mTOR Signaling Pathway and Inhibiting FoxO3a In Vitro and In Vivo. J Microbiol Biotechnol 2023; 33:1635-1647. [PMID: 37674382 PMCID: PMC10772550 DOI: 10.4014/jmb.2306.06012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 09/08/2023]
Abstract
Muscle atrophy, which is defined as a decrease in muscle mass and strength, is caused by an imbalance between the anabolism and catabolism of muscle proteins. Thus, modulating the homeostasis between muscle protein synthesis and degradation represents an efficient treatment approach for this condition. In the present study, the protective effects against muscle atrophy of ethanol extracts of Morus alba L. (MA) and Angelica keiskei Koidz. (AK) leaves and their mixtures (MIX) were evaluated in vitro and in vivo. Our results showed that MIX increased 5-aminoimidazole-4-carboxamide ribonucleotide-induced C2C12 myotube thinning, and enhanced soleus and gastrocnemius muscle thickness compared to each extract alone in dexamethasone-induced muscle atrophy Sprague Dawley rats. In addition, although MA and AK substantially improved grip strength and histological changes for dexamethasone-induced muscle atrophy in vivo, the efficacy was superior in the MIX-treated group. Moreover, MIX further increased the expression levels of myogenic factors (MyoD and myogenin) and decreased the expression levels of E3 ubiquitin ligases (atrogin-1 and muscle-specific RING finger protein-1) in vitro and in vivo compared to the MA- and AK-alone treatment groups. Furthermore, MIX increased the levels of phosphorylated phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and mammalian target of rapamycin (mTOR) that were reduced by dexamethasone, and downregulated the expression of forkhead box O3 (FoxO3a) induced by dexamethasone. These results suggest that MIX has a protective effect against muscle atrophy by enhancing muscle protein anabolism through the activation of the PI3K/Akt/mTOR signaling pathway and attenuating catabolism through the inhibition of FoxO3a.
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Affiliation(s)
- Hyun Hwangbo
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Republic of Korea
| | - Min Yeong Kim
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Republic of Korea
| | - Seon Yeong Ji
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Republic of Korea
| | - Da Hye Kim
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Republic of Korea
| | - Beom Su Park
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Republic of Korea
| | - Seong Un Jeong
- Hamsoa Pharmaceutical Co., Ltd., Iksan 54524, Republic of Korea
| | - Jae Hyun Yoon
- Hamsoa Pharmaceutical Co., Ltd., Iksan 54524, Republic of Korea
| | - Tae Hee Kim
- Hamsoa Pharmaceutical Co., Ltd., Iksan 54524, Republic of Korea
| | - Gi-Young Kim
- Department of Marine Life Science, Jeju National University, Jeju 63243, Republic of Korea
| | - Yung Hyun Choi
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Republic of Korea
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Republic of Korea
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Stadhouders LEM, Smith JAB, Gabriel BM, Verbrugge SAJ, Hammersen TD, Kolijn D, Vogel ISP, Mohamed AD, de Wit GMJ, Offringa C, Hoogaars WMH, Gehlert S, Wackerhage H, Jaspers RT. Myotube growth is associated with cancer-like metabolic reprogramming and is limited by phosphoglycerate dehydrogenase. Exp Cell Res 2023; 433:113820. [PMID: 37879549 DOI: 10.1016/j.yexcr.2023.113820] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 10/10/2023] [Accepted: 10/14/2023] [Indexed: 10/27/2023]
Abstract
The Warburg effect links growth and glycolysis in cancer. A key purpose of the Warburg effect is to generate glycolytic intermediates for anabolic reactions, such as nucleotides → RNA/DNA and amino acids → protein synthesis. The aim of this study was to investigate whether a similar 'glycolysis-for-anabolism' metabolic reprogramming also occurs in hypertrophying skeletal muscle. To interrogate this, we first induced C2C12 myotube hypertrophy with IGF-1. We then added 14C glucose to the differentiation medium and measured radioactivity in isolated protein and RNA to establish whether 14C had entered anabolism. We found that especially protein became radioactive, suggesting a glucose → glycolytic intermediates → non-essential amino acid(s) → protein series of reactions, the rate of which was increased by IGF-1. Next, to investigate the importance of glycolytic flux and non-essential amino acid synthesis for myotube hypertrophy, we exposed C2C12 and primary mouse myotubes to the glycolysis inhibitor 2-Deoxy-d-glucose (2DG). We found that inhibiting glycolysis lowered C2C12 and primary myotube size. Similarly, siRNA silencing of PHGDH, the key enzyme of the serine biosynthesis pathway, decreased C2C12 and primary myotube size; whereas retroviral PHGDH overexpression increased C2C12 myotube size. Together these results suggest that glycolysis is important for hypertrophying myotubes, which reprogram their metabolism to facilitate anabolism, similar to cancer cells.
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Affiliation(s)
- Lian E M Stadhouders
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Jonathon A B Smith
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK; Department of Physiology and Pharmacology (FYFA), Group of Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Brendan M Gabriel
- Aberdeen Cardiovascular & Diabetes Centre, The Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Sander A J Verbrugge
- Exercise Biology, Department for Sport and Health Sciences, Technical University of Munich, Georg-Brauchle-Ring 60/62, 80992, München/Munich, Germany
| | - Tim D Hammersen
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Detmar Kolijn
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands; Department of Clinical Pharmacology and Molecular Cardiology, Ruhr University Bochum, Bochum, Germany
| | - Ilse S P Vogel
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Abdalla D Mohamed
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK; Cancer Therapeutics Unit, Target Genomic and Chromosomal Instability, The Institute of Cancer Research, 15 Cotswold Road, Sutton, London, SM2 5NG, UK
| | - Gerard M J de Wit
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Carla Offringa
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Willem M H Hoogaars
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Sebastian Gehlert
- Department for the Biosciences of Sports, Institute of Sports Science, University of Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany; Department for Molecular and Cellular Sports Medicine, German Sport University Cologne, 50933, Cologne, Germany
| | - Henning Wackerhage
- Exercise Biology, Department for Sport and Health Sciences, Technical University of Munich, Georg-Brauchle-Ring 60/62, 80992, München/Munich, Germany
| | - Richard T Jaspers
- Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands.
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Michel JM, Godwin JS, Plotkin DL, Mesquita PHC, McIntosh MC, Ruple BA, Libardi CA, Mobley CB, Kavazis AN, Roberts MD. Proteolytic markers associated with a gain and loss of leg muscle mass with resistance training followed by high-intensity interval training. Exp Physiol 2023; 108:1268-1281. [PMID: 37589512 PMCID: PMC10543615 DOI: 10.1113/ep091286] [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: 05/08/2023] [Accepted: 08/03/2023] [Indexed: 08/18/2023]
Abstract
We recently reported that vastus lateralis (VL) cross-sectional area (CSA) increases after 7 weeks of resistance training (RT, 2 days/week), with declines occurring following 7 weeks of subsequent treadmill high-intensity interval training (HIIT) (3 days/week). Herein, we examined the effects of this training paradigm on skeletal muscle proteolytic markers. VL biopsies were obtained from 11 untrained college-aged males at baseline (PRE), after 7 weeks of RT (MID), and after 7 weeks of HIIT (POST). Tissues were analysed for proteolysis markers, and in vitro experiments were performed to provide additional insights. Atrogene mRNAs (TRIM63, FBXO32, FOXO3A) were upregulated at POST versus both PRE and MID (P < 0.05). 20S proteasome core protein abundance increased at POST versus PRE (P = 0.031) and MID (P = 0.049). 20S proteasome activity, and protein levels for calpain-2 and Beclin-1 increased at MID and POST versus PRE (P < 0.05). Ubiquitinated proteins showed model significance (P = 0.019) with non-significant increases at MID and POST (P > 0.05). in vitro experiments recapitulated the training phenotype when stimulated with a hypertrophic stimulus (insulin-like growth factor 1; IGF1) followed by a subsequent AMP-activated protein kinase activator (5-aminoimidazole-4-carboxamide ribonucleotide; AICAR), as demonstrated by larger myotube diameter in IGF1-treated cells versus IGF1 followed by AICAR treatments (I+A; P = 0.017). Muscle protein synthesis (MPS) levels were also greater in IGF1-treated versus I+A myotubes (P < 0.001). In summary, the loss in RT-induced VL CSA with HIIT coincided with increases in several proteolytic markers, and sustained proteolysis may have driven this response. Moreover, while not measured in humans, we interpret our in vitro data to suggest that (unlike RT) HIIT does not stimulate MPS. NEW FINDINGS: What is the central question of this study? Determining if HIIT-induced reductions in muscle hypertrophy following a period of resistance training coincided with increases in proteolytic markers. What is the main finding and its importance? Several proteolytic markers were elevated during the HIIT training period implying that increases in muscle proteolysis may have played a role in HIIT-induced reductions in muscle hypertrophy.
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Affiliation(s)
| | | | | | | | | | | | - Cleiton A. Libardi
- Department of Physical EducationFederal University of Sao CarlosSao CarlosBrazil
| | | | | | - Michael D. Roberts
- School of KinesiologyAuburn UniversityAuburnALUSA
- Edward Via College of Osteopathic MedicineAuburnALUSA
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Gellhaus B, Böker KO, Gsaenger M, Rodenwaldt E, Hüser MA, Schilling AF, Saul D. Foxo3 Knockdown Mediates Decline of Myod1 and Myog Reducing Myoblast Conversion to Myotubes. Cells 2023; 12:2167. [PMID: 37681900 PMCID: PMC10486649 DOI: 10.3390/cells12172167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/18/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
Sarcopenia has a high prevalence among the aging population. Sarcopenia is of tremendous socioeconomic importance because it can lead to falls and hospitalization, subsequently increasing healthcare costs while limiting quality of life. In sarcopenic muscle fibers, the E3 ubiquitin ligase F-Box Protein 32 (Fbxo32) is expressed at substantially higher levels, driving ubiquitin-proteasomal muscle protein degradation. As one of the key regulators of muscular equilibrium, the transcription factor Forkhead Box O3 (FOXO3) can increase the expression of Fbxo32, making it a possible target for the regulation of this detrimental pathway. To test this hypothesis, murine C2C12 myoblasts were transduced with AAVs carrying a plasmid for four specific siRNAs against Foxo3. Successfully transduced myoblasts were selected via FACS cell sorting to establish single clone cell lines. Sorted myoblasts were further differentiated into myotubes and stained for myosin heavy chain (MHC) by immunofluorescence. The resulting area was calculated. Myotube contractions were induced by electrical stimulation and quantified. We found an increased Foxo3 expression in satellite cells in human skeletal muscle and an age-related increase in Foxo3 expression in older mice in silico. We established an in vitro AAV-mediated FOXO3 knockdown on protein level. Surprisingly, the myotubes with FOXO3 knockdown displayed a smaller myotube size and a lower number of nuclei per myotube compared to the control myotubes (AAV-transduced with a functionless control plasmid). During differentiation, a lower level of FOXO3 reduced the expression Fbxo32 within the first three days. Moreover, the expression of Myod1 and Myog via ATM and Tp53 was reduced. Functionally, the Foxo3 knockdown myotubes showed a higher contraction duration and time to peak. Early Foxo3 knockdown seems to terminate the initiation of differentiation due to lack of Myod1 expression, and mediates the inhibition of Myog. Subsequently, the myotube size is reduced and the excitability to electrical stimulation is altered.
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Affiliation(s)
- Benjamin Gellhaus
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Goettingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany; (B.G.); (K.O.B.); (E.R.); (A.F.S.)
| | - Kai O. Böker
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Goettingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany; (B.G.); (K.O.B.); (E.R.); (A.F.S.)
| | - Marlene Gsaenger
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Goettingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany; (B.G.); (K.O.B.); (E.R.); (A.F.S.)
| | - Eyck Rodenwaldt
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Goettingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany; (B.G.); (K.O.B.); (E.R.); (A.F.S.)
| | - Marc A. Hüser
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center Goettingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany;
| | - Arndt F. Schilling
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Goettingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany; (B.G.); (K.O.B.); (E.R.); (A.F.S.)
| | - Dominik Saul
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Goettingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany; (B.G.); (K.O.B.); (E.R.); (A.F.S.)
- Department of Trauma and Reconstructive Surgery, Eberhard Karls University Tübingen, BG Trauma Center Tübingen, 72076 Tübingen, Germany
- Kogod Center on Aging and Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
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Rivera CN, Hinkle JS, Watne RM, Macgowan TC, Wommack AJ, Vaughan RA. PPAR β/ δ Agonism with GW501516 Increases Myotube PGC-1 α Content and Reduces BCAA Media Content Independent of Changes in BCAA Catabolic Enzyme Expression. PPAR Res 2023; 2023:4779199. [PMID: 37325367 PMCID: PMC10264138 DOI: 10.1155/2023/4779199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 05/01/2023] [Accepted: 05/17/2023] [Indexed: 06/17/2023] Open
Abstract
Background Type 2 diabetes is characterized by reduced insulin sensitivity, elevated blood metabolites, and reduced mitochondrial metabolism with reduced expression of genes governing metabolism such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). PGC-1α regulates the expression of branched-chain amino acid (BCAA) metabolism, and thus, increased circulating BCAA in diabetics may be partially explained by reduced PGC-1α expression. PGC-1α functions in-part through interactions with peroxisome proliferator-activated receptor β/δ (PPARβ/δ). The present report examined the effects of the PPARβ/δ agonism on cell metabolism and related gene/protein expression of cultured myotubes, with a primary emphasis on determining the effects of GW on BCAA disposal and catabolic enzyme expression. Methods C2C12 myotubes were treated with GW501516 (GW) for up to 24 hours. Mitochondrial and glycolytic metabolism were measured via oxygen consumption and extracellular acidification rate, respectively. Metabolic gene and protein expression were assessed via quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. Media BCAA content was assessed via liquid chromatography-mass spectrometry (LC/MS). Results GW significantly increased PGC-1α protein expression, mitochondrial content, and mitochondrial function. GW also significantly reduced BCAA content within culture media following 24-hour treatment; however, expression of BCAA catabolic enzymes/transporter was unchanged. Conclusion These data confirm the ability of GW to increase muscle PGC-1α content and decrease BCAA media content without affecting BCAA catabolic enzymes/transporter. These findings suggest heightened BCAA uptake (and possibly metabolism) may occur without substantial changes in the protein levels of related cell machinery.
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Affiliation(s)
- Caroline N. Rivera
- Department of Exercise Science, High Point University, High Point, NC, USA
| | - Jason S. Hinkle
- Department of Exercise Science, High Point University, High Point, NC, USA
| | - Rachel M. Watne
- Department of Chemistry, High Point University, High Point, NC, USA
| | | | | | - Roger A. Vaughan
- Department of Exercise Science, High Point University, High Point, NC, USA
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Signals for Muscular Protein Turnover and Insulin Resistance in Critically Ill Patients: A Narrative Review. Nutrients 2023; 15:nu15051071. [PMID: 36904071 PMCID: PMC10005516 DOI: 10.3390/nu15051071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/24/2023] Open
Abstract
Sarcopenia in critically ill patients is a highly prevalent comorbidity. It is associated with a higher mortality rate, length of mechanical ventilation, and probability of being sent to a nursing home after the Intensive Care Unit (ICU). Despite the number of calories and proteins delivered, there is a complex network of signals of hormones and cytokines that affect muscle metabolism and its protein synthesis and breakdown in critically ill and chronic patients. To date, it is known that a higher number of proteins decreases mortality, but the exact amount needs to be clarified. This complex network of signals affects protein synthesis and breakdown. Some hormones regulate metabolism, such as insulin, insulin growth factor glucocorticoids, and growth hormone, whose secretion is affected by feeding states and inflammation. In addition, cytokines are involved, such as TNF-alpha and HIF-1. These hormones and cytokines have common pathways that activate muscle breakdown effectors, such as the ubiquitin-proteasome system, calpain, and caspase-3. These effectors are responsible for protein breakdown in muscles. Many trials have been conducted with hormones with different results but not with nutritional outcomes. This review examines the effect of hormones and cytokines on muscles. Knowing all the signals and pathways that affect protein synthesis and breakdown can be considered for future therapeutics.
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Nagendra AH, Ray A, Chaudhury D, Mitra A, Ranade AV, Bose B, Shenoy P. S. Sodium fluoride induces skeletal muscle atrophy via changes in mitochondrial and sarcomeric proteomes. PLoS One 2022; 17:e0279261. [PMID: 36548359 PMCID: PMC9779014 DOI: 10.1371/journal.pone.0279261] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Sodium Fluoride (NaF) can change the expression of skeletal muscle proteins. Since skeletal muscle is rich in mitochondrial and contractile (sarcomeric) proteins, these proteins are sensitive to the effects of NaF, and the changes are dose-and time-dependent. In the current study, we have analysed the effect of high concentrations of NaF (80ppm) on mouse skeletal muscle at two different time points, i.e., 15 days and 60 days. At the end of the experimental time, the animals were sacrificed, skeletal muscles were isolated, and proteins were extracted and subjected to bioinformatic (Mass Spectrometric) analysis. The results were analysed based on changes in different mitochondrial complexes, contractile (sarcomeric) proteins, 26S proteasome, and ubiquitin-proteasome pathway. The results showed that the mitochondrial proteins of complex I, II, III, IV and V were differentially regulated in the groups treated with 80ppm of NaF for 15 days and 60 days. The network analysis indicated more changes in mitochondrial proteins in the group treated with the higher dose for 15 days rather than 60 days. Furthermore, differential expression of (sarcomeric) proteins, downregulation of 26S proteasome subunits, and differential expression in proteins related to the ubiquitin-proteasome pathway lead to muscle atrophy. The differential expression might be due to the adaptative mechanism to counteract the deleterious effects of NaF on energy metabolism. Data are available via ProteomeXchange with identifier PXD035014.
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Affiliation(s)
- Apoorva H. Nagendra
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya Deemed to be University, Deralakatte, Mangalore, India
| | - Animikh Ray
- Father Muller Research Centre, Father Muller Medical College, Father Muller Charitable Institutions, Kankanady, Mangalore, Karnataka, India
| | - Debajit Chaudhury
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya Deemed to be University, Deralakatte, Mangalore, India
| | - Akash Mitra
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya Deemed to be University, Deralakatte, Mangalore, India
| | - Anu Vinod Ranade
- Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Bipasha Bose
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya Deemed to be University, Deralakatte, Mangalore, India
| | - Sudheer Shenoy P.
- Stem Cells and Regenerative Medicine Centre, Yenepoya Research Centre, Yenepoya Deemed to be University, Deralakatte, Mangalore, India
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Lee JA, Lee SH, Shin MR, Park HJ, Roh SS. Gardeniae Fructus Extract Alleviates Dexamethasone-Induced Muscle Atrophy in Mice. J Med Food 2022; 25:882-891. [PMID: 36084316 DOI: 10.1089/jmf.2022.k.0038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Muscle atrophy (MA) is a case in which protein degeneration occurs excessively due to an imbalance between protein synthesis and breakdown, and is characterized by decreased muscle mass and weakened muscle strength. Despite mounting concern about MA, the number of patients with MA is increasing every year. The aim of the present study was to assess the impact of Gardeniae Fructus (GF) hot water extract on dexamethasone (DEX)-induced MA in mice. C57BL/6N mice were grouped (n = 8) as follows: Normal mice (Normal), MA mice were treated with distilled water (Control), MA mice were treated with GF 100 mg/kg (GF100), MA mice were treated with GF 200 mg/kg (GF200). For 10 days, DEX (25 mg/kg body weight, i.p.) injection was used to induce MA, and GF was administered. GF treatment restored the muscle weight decreased due to MA, and in particular, the weights of EDL+TA and Sol were significantly increased in the GF200 group. Also, it was confirmed that the swimming time was improved in the GF200 group. In addition, the expression of NADPH oxidase related to oxidative stress was significantly reduced, and protective (insulin-like growth factor I/phosphoinositide 3-kinase/protein kinase B pathway) and catabolic (AMP-activated kinase [AMPK]/sirtuin 1 [SIRT1]/proliferator-activated receptor-gamma coactivator-1α (PGC-1α)-forkhead box O (FOXO) pathway) pathways were significantly modulated. These results demonstrate that GF regulates muscle protein synthesis and catabolic pathways, and in particular, it is judged to improve MA by regulating the proteolytic AMPK/SIRT1/PGC-1α-FOXO pathway.
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Affiliation(s)
- Jin A Lee
- Department of Herbology, College of Korean Medicine, Daegu Haany University, Daegu, Korea
| | - Se Hui Lee
- Department of Herbology, College of Korean Medicine, Daegu Haany University, Daegu, Korea
| | - Mi-Rae Shin
- Department of Herbology, College of Korean Medicine, Daegu Haany University, Daegu, Korea
| | - Hae-Jin Park
- DHU Bio Convergence Testing Center, Gyeongsan, Korea
| | - Seong-Soo Roh
- Department of Herbology, College of Korean Medicine, Daegu Haany University, Daegu, Korea
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Ren C, Liu F, Xing C, Zhao R, Tang X, Liu M, Gao W, Shen J. IL-37 alleviates liver granuloma caused by Schistosoma japonicum infection by inducing alternative macrophage activation. Parasit Vectors 2022; 15:300. [PMID: 36002836 PMCID: PMC9404629 DOI: 10.1186/s13071-022-05420-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 07/26/2022] [Indexed: 11/10/2022] Open
Abstract
Background Hepatic macrophages regulate liver granuloma formation and fibrosis caused by infection with Schistosoma japonicum, with the manner of regulation dependent on macrophage activation state. Interleukin (IL)-37 may have immunomodulatory effects on macrophages. However, whether IL-37 can affect liver granuloma formation and fibrosis by affecting the polarization of macrophages in S. japonicum infection remains unclear. The aim of this study was to investigate IL-37-affected macrophage polarization in liver granuloma formation and fibrosis in S. japonicum infection. Methods An enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of IL-37 in the serum of patients with acute S. japonicum infection and in the serum of healthy people. Recombinant IL-37 (rIL-37), CPP-IgG2Fc-IL-37 and no CPP-IgG2Fc-IL-37 proteins were injected into S. japonicum-infected mice every 3 days for a total of 6 times from day 24 post infection onwards. Subsequently, ELISA, quantitative reverse transcription-PCR, fluorescence-activated cell sorting and western blot were used to analyze whether IL-37 inhibits the formation of liver granulomas and the development of liver fibrosis by regulating the phenotypic transition of macrophages. Finally, the three IL-37 proteins and SIS3, a Smad3 inhibitor, were co-cultured in mouse peritoneal macrophages to explore the mechanism underlying the promotion of the polarization of M0 macrophages to the M2 phenotype by IL-37. Results Serum IL-37 levels were upregulated in schistosomiasis patients, and this increased level of IL-37 protein apparently alleviated the liver granuloma of mice in infection models. It also could induce liver and peritoneal macrophages to polarize to the M2 phenotype in S. japonicum-infected mice. The S. japonicum-infected mice injected with CPP-IgG2Fc-IL-37 group exhibited the most obvious improvement in inflammatory reaction against the liver granuloma. The number and ratio of M2 macrophages in the liver and peritoneal cavity were significantly higher in the three IL-37 protein groups, especially in the CPP-IgG2Fc-IL-37 group, compared to the controls. Similar results were also found regarding liver function damage. IL-37 induced macrophage M2 polarization by promoting AMP-activated protein kinase (AMPK) phosphorylation in vitro. Among all groups, the activation of AMPK was most significant in the CPP-IgG2Fc-IL-37 group, and it was found that SMAD3 could enhance the anti-inflammatory function of IL-37. Conclusions The results show that IL-37 was able to promote the polarization of macrophages to the M2 phenotype, thereby inhibiting the development of schistosomiasis. In comparison to the rIL-37 protein, the CPP-IgG2Fc-IL-37 protein has the advantages of being effective in small doses and having fewer side effects and a better efficacy. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05420-6.
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Affiliation(s)
- Cuiping Ren
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology; Anhui Provincial Laboratory of Zoonoses; Laboratory of Tropical and Parasitic Diseases Control; School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China
| | - Fengchun Liu
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology; Anhui Provincial Laboratory of Zoonoses; Laboratory of Tropical and Parasitic Diseases Control; School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.,Anhui Provincial Center for Clinical Laboratories, The First Affiliated Hospital of University of Science and Technology of China, Hefei, 230032, China
| | - Chen Xing
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology; Anhui Provincial Laboratory of Zoonoses; Laboratory of Tropical and Parasitic Diseases Control; School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China
| | - Ruyu Zhao
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology; Anhui Provincial Laboratory of Zoonoses; Laboratory of Tropical and Parasitic Diseases Control; School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China
| | - Xiaoxue Tang
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology; Anhui Provincial Laboratory of Zoonoses; Laboratory of Tropical and Parasitic Diseases Control; School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China
| | - Miao Liu
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology; Anhui Provincial Laboratory of Zoonoses; Laboratory of Tropical and Parasitic Diseases Control; School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China
| | - Wenda Gao
- Antagen Institute for Biomedical Research, Boston, MA, 02118, USA.
| | - Jijia Shen
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology; Anhui Provincial Laboratory of Zoonoses; Laboratory of Tropical and Parasitic Diseases Control; School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
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10
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Chang M, Huhn S, Nelson L, Betenbaugh M, Du Z. Significant impact of mTORC1 and ATF4 pathways in CHO cell recombinant protein production induced by CDK4/6 inhibitor. Biotechnol Bioeng 2022; 119:1189-1206. [PMID: 35112712 DOI: 10.1002/bit.28050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/03/2022] [Accepted: 01/24/2022] [Indexed: 11/11/2022]
Abstract
The CDK4/6 inhibitor has been shown to increase recombinant protein productivity in Chinese hamster ovary cells (CHO). Therefore, we investigated the mechanism that couples cell cycle inhibitor (CCI) treatment with protein productivity utilizing proteomics and phosphoproteomics. We identified mTORC1 as a critical early signaling event that preceded boosted productivity. Following CCI treatment, mTOR exhibited a transient increase in phosphorylation at a novel site that is also conserved in human and mouse. Upstream of mTORC1, increased phosphorylation of AKT1S1 and decreased phosphorylation of RB1 may provide molecular links between CDK4/6 inhibition and mTORC1. Downstream, increased EIF4EBP phosphorylation was observed, which can mediate cap-dependent translation. In addition, the collective effect of increased phosphorylation of RPS6, increased phosphorylation of regulators of RNA polymerase I, and increased protein expression in tRNA-aminoacylation pathway may contribute to enhancing the translational apparatus for increased productivity. In concert, an elevated stress response via GCN2/EIF2AK4-ATF4 axis persisted over the treatment course, which may link mTOR to downstream responses including the unfolded protein response (UPR) and autophagy to enhance proper protein folding and secretion. Together, this comprehensive proteomics and phosphoproteomics characterization of CCI treated CHO cells offers insights into understanding multiple aspects of signaling events resulting from CDK4/CDK6 inhibition. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Meiping Chang
- Process Cell Sciences, Biologics Process R&D, Merck & Co., Inc., Kenilworth, NJ, USA
| | - Steven Huhn
- Process Cell Sciences, Biologics Process R&D, Merck & Co., Inc., Kenilworth, NJ, USA
| | - Luke Nelson
- Process Cell Sciences, Biologics Process R&D, Merck & Co., Inc., Kenilworth, NJ, USA
| | - Michael Betenbaugh
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Zhimei Du
- Process Cell Sciences, Biologics Process R&D, Merck & Co., Inc., Kenilworth, NJ, USA
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11
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AICAR stimulates mitochondrial biogenesis and BCAA catabolic enzyme expression in C2C12 myotubes. Biochimie 2021; 195:77-85. [PMID: 34798200 DOI: 10.1016/j.biochi.2021.11.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/27/2021] [Accepted: 11/11/2021] [Indexed: 11/21/2022]
Abstract
Type 2 diabetes is characterized by reduced insulin sensitivity, elevated blood metabolites, and reduced mitochondrial metabolism. Insulin resistant populations often exhibit reduced expression of genes governing mitochondrial metabolism such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Interestingly, PGC-1α regulates the expression of branched-chain amino acid (BCAA) metabolism, and thus, the consistently observed increased circulating levels of BCAA in diabetics may be partially explained by reduced PGC-1α expression. Conversely, PGC-1α upregulation appears to increase BCAA catabolism. PGC-1α activity is regulated by 5'-AMP-activated protein kinase (AMPK), however, only limited experimental data exists on the effect of AMPK activation in the regulation of BCAA catabolism. The present report examined the effects of the commonly used AMPK activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) on the metabolism and expression of several related targets (including BCAA catabolic enzymes) of cultured myotubes. C2C12 myotubes were treated with AICAR at 1 mM for up to 24 h. Mitochondrial and glycolytic metabolism were measured via oxygen consumption and extracellular acidification rate, respectively. Metabolic gene and protein expression were assessed via qRT-PCR and western blot, respectively. AICAR treatment significantly increased mitochondrial content and peak mitochondrial capacity. AICAR treatment also increased AMPK activation and mRNA expression of several regulators of mitochondrial biogenesis but reduced glycolytic metabolism and mRNA expression of several glycolytic enzymes. Interestingly, branched-chain alpha-keto acid dehydrogenase a (BCKDHa) protein was significantly increased following AICAR-treatment suggesting increased overall BCAA catabolic capacity in AICAR-treated cells. Together, these experiments demonstrate AICAR/AMPK activation can upregulate BCAA catabolic machinery in a model of skeletal muscle.
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12
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Jo K, Jang WY, Yun BS, Kim JS, Lee HS, Chang YB, Suh HJ. Effect of Deer Antler Extract on Muscle Differentiation and 5-Aminoimidazole-4-Carboxamide Ribonucleoside (AICAR)-Induced Muscle Atrophy in C2C12 Cells. Food Sci Anim Resour 2021; 41:623-635. [PMID: 34291211 PMCID: PMC8277185 DOI: 10.5851/kosfa.2021.e20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/13/2021] [Accepted: 04/08/2021] [Indexed: 11/06/2022] Open
Abstract
The effect of deer antler extract on muscle differentiation and muscle atrophy
were evaluated to minimize muscle loss following aging. Various deer antler
extracts (HWE, hot water extract of deer antler; FE, HWE of fermented deer
antler; ET, enzyme-assisted extract of deer antler; UE, extract prepared by
ultrasonication of deer antler) were evaluated for their effect on muscle
differentiation and inhibition of 5-aminoimidazole-4-carboxamide ribonucleoside
(AICAR)-induced muscle atrophy in C2C12 cells. Morphological changes according
to the effect of antler extracts on muscle differentiation were confirmed by
Jenner-Giemsa staining. In addition, the expression levels of genes related to
muscle differentiation and atrophy were confirmed through qRT-PCR. In the
presence of antler extracts, the length and thickness of myotubes and myogenin
differentiation 1 (MyoD1) and myogenic factor 5 (Myf5) gene expression were
increased compared to those in the control group (CON). Gene expression of
AMP-activated protein kinase (AMPK), MyoD1, and myogenin, along with the muscle
atrophy factors muscle RING finger-1 (MuRF-1) and forkhead box O3a (FoxO3a) upon
addition of deer antler extracts to muscle-atrophied C2C12 cells was determined
by qRT-PCR after treatment with AICAR. The expression of MuRF-1 and FoxO3a
decreased in the groups treated with antler extracts compared to that in the
group treated with AICAR alone. In addition, gene expression of MyoD1 and
myogenin in the muscle atrophy cell model was significantly increased compared
that into the CON. Therefore, our findings indicate that antler extract can
increase the expression of MyoD1, Myf5 and myogenin, inhibit muscle atrophy, and
promote muscle differentiation.
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Affiliation(s)
- Kyungae Jo
- Department of Integrated Biomedical and Life Sciences, Graduate School, Korea University, Seoul 02841, Korea
| | - Woo Young Jang
- Department of Integrated Biomedical and Life Sciences, Graduate School, Korea University, Seoul 02841, Korea
| | - Beom Sik Yun
- R D Center, Kwangdong Pharm Co., Ltd, Seoul 08381, Korea
| | - Jin Soo Kim
- R D Center, Kwangdong Pharm Co., Ltd, Seoul 08381, Korea
| | - Hyun-Sun Lee
- Agency for Korea National Food Cluster, Iksan 54576, Korea
| | - Yeok Boo Chang
- Department of Integrated Biomedical and Life Sciences, Graduate School, Korea University, Seoul 02841, Korea
| | - Hyung Joo Suh
- Department of Integrated Biomedical and Life Sciences, Graduate School, Korea University, Seoul 02841, Korea
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13
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McDermott MM, Dayanidhi S, Kosmac K, Saini S, Slysz J, Leeuwenburgh C, Hartnell L, Sufit R, Ferrucci L. Walking Exercise Therapy Effects on Lower Extremity Skeletal Muscle in Peripheral Artery Disease. Circ Res 2021; 128:1851-1867. [PMID: 34110902 DOI: 10.1161/circresaha.121.318242] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Walking exercise is the most effective noninvasive therapy that improves walking ability in peripheral artery disease (PAD). Biologic mechanisms by which exercise improves walking in PAD are unclear. This review summarizes evidence regarding effects of walking exercise on lower extremity skeletal muscle in PAD. In older people without PAD, aerobic exercise improves mitochondrial activity, muscle mass, capillary density, and insulin sensitivity in skeletal muscle. However, walking exercise increases lower extremity ischemia in people with PAD, and therefore, mechanisms by which this exercise improves walking may differ between people with and without PAD. Compared with people without PAD, gastrocnemius muscle in people with PAD has greater mitochondrial impairment, increased reactive oxygen species, and increased fibrosis. In multiple small trials, walking exercise therapy did not consistently improve mitochondrial activity in people with PAD. In one 12-week randomized trial of people with PAD randomized to supervised exercise or control, supervised treadmill exercise increased treadmill walking time from 9.3 to 15.1 minutes, but simultaneously increased the proportion of angular muscle fibers, consistent with muscle denervation (from 7.6% to 15.6%), while angular myofibers did not change in the control group (from 9.1% to 9.1%). These findings suggest an adaptive response to exercise in PAD that includes denervation and reinnervation, an adaptive process observed in skeletal muscle of people without PAD during aging. Small studies have not shown significant effects of exercise on increased capillary density in lower extremity skeletal muscle of participants with PAD, and there are no data showing that exercise improves microcirculatory delivery of oxygen and nutrients in patients with PAD. However, the effects of supervised exercise on increased plasma nitrite abundance after a treadmill walking test in people with PAD may be associated with improved lower extremity skeletal muscle perfusion and may contribute to improved walking performance in response to exercise in people with PAD. Randomized trials with serial, comprehensive measures of muscle biology, and physiology are needed to clarify mechanisms by which walking exercise interventions improve mobility in PAD.
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Affiliation(s)
- Mary M McDermott
- Department of Medicine and Preventive Medicine (M.M.M., J.S.), Northwestern University Feinberg School of Medicine
| | - Sudarshan Dayanidhi
- Shirley Ryan Ability Laboratory (S.D.), Northwestern University Feinberg School of Medicine
| | - Kate Kosmac
- Center for Muscle Biology, University of Kentucky (K.K.)
| | - Sunil Saini
- Jawaharlal Nehru University, School of Biotechnology, New Delhi, India (S.S.)
| | - Joshua Slysz
- Department of Medicine and Preventive Medicine (M.M.M., J.S.), Northwestern University Feinberg School of Medicine
| | | | - Lisa Hartnell
- Division of Intramural Research, National Institute on Aging (L.H., L.F.)
| | - Robert Sufit
- Department of Neurology (R.S.), Northwestern University Feinberg School of Medicine
| | - Luigi Ferrucci
- Division of Intramural Research, National Institute on Aging (L.H., L.F.)
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14
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White JP. Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand. Front Cell Dev Biol 2021; 9:656604. [PMID: 34136478 PMCID: PMC8201612 DOI: 10.3389/fcell.2021.656604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/28/2021] [Indexed: 11/20/2022] Open
Abstract
Skeletal muscle protein synthesis is a highly complex process, influenced by nutritional status, mechanical stimuli, repair programs, hormones, and growth factors. The molecular aspects of protein synthesis are centered around the mTORC1 complex. However, the intricacies of mTORC1 regulation, both up and downstream, have expanded overtime. Moreover, the plastic nature of skeletal muscle makes it a unique tissue, having to coordinate between temporal changes in myofiber metabolism and hypertrophy/atrophy stimuli within a tissue with considerable protein content. Skeletal muscle manages the push and pull between anabolic and catabolic pathways through key regulatory proteins to promote energy production in times of nutrient deprivation or activate anabolic pathways in times of nutrient availability and anabolic stimuli. Branched-chain amino acids (BCAAs) can be used for both energy production and signaling to induce protein synthesis. The metabolism of BCAAs occur in tandem with energetic and anabolic processes, converging at several points along their respective pathways. The fate of intramuscular BCAAs adds another layer of regulation, which has consequences to promote or inhibit muscle fiber protein anabolism. This review will outline the general mechanisms of muscle protein synthesis and describe how metabolic pathways can regulate this process. Lastly, we will discuss how BCAA availability and demand coordinate with synthesis mechanisms and identify key factors involved in intramuscular BCAA trafficking.
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Affiliation(s)
- James P White
- Department of Medicine, Duke University School of Medicine, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, United States.,Duke Center for the Study of Aging and Human Development, Duke University School of Medicine, Durham, NC, United States
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15
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Lin YA, Li YR, Chang YC, Hsu MC, Chen ST. Activation of IGF-1 pathway and suppression of atrophy related genes are involved in Epimedium extract (icariin) promoted C2C12 myotube hypertrophy. Sci Rep 2021; 11:10790. [PMID: 34031457 PMCID: PMC8144409 DOI: 10.1038/s41598-021-89039-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 04/12/2021] [Indexed: 02/07/2023] Open
Abstract
The regenerative effect of Epimedium and its major bioactive flavonoid icariin (ICA) have been documented in traditional medicine, but their effect on sarcopenia has not been evaluated. The aim of this study was to investigate the effects of Epimedium extract (EE) on skeletal muscle as represented by differentiated C2C12 cells. Here we demonstrated that EE and ICA stimulated C2C12 myotube hypertrophy by activating several, including IGF-1 signal pathways. C2C12 myotube hypertrophy was demonstrated by enlarged myotube and increased myosin heavy chains (MyHCs). In similar to IGF-1, EE/ICA activated key components of the IGF-1 signal pathway, including IGF-1 receptor. Pre-treatment with IGF-1 signal pathway specific inhibitors such as picropodophyllin, LY294002, and rapamycin attenuated EE induced myotube hypertrophy and MyHC isoform overexpression. In a different way, EE induced MHyC-S overexpression can be blocked by AMPK, but not by mTOR inhibitor. On the level of transcription, EE suppressed myostatin and MRF4 expression, but did not suppress atrogenes MAFbx and MuRF1 like IGF-1 did. Differential regulation of MyHC isoform and atrogenes is probably due to inequivalent AKT and AMPK phosphorylation induced by EE and IGF-1. These findings suggest that EE/ICA stimulates pathways partially overlapping with IGF-1 signaling pathway to promote myotube hypertrophy.
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Affiliation(s)
- Yi-An Lin
- Department of Sports Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan.,Division of Endocrinology and Metabolism, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan City, Taiwan.,Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, Taoyuan City, Taiwan
| | - Yan-Rong Li
- Division of Endocrinology and Metabolism, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan City, Taiwan
| | - Yi-Ching Chang
- Division of Endocrinology and Metabolism, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan City, Taiwan
| | - Mei-Chich Hsu
- Department of Sports Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan.
| | - Szu-Tah Chen
- Division of Endocrinology and Metabolism, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan City, Taiwan.
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16
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Cachexia as Evidence of the Mechanisms of Resistance and Tolerance during the Evolution of Cancer Disease. Int J Mol Sci 2021; 22:ijms22062890. [PMID: 33809200 PMCID: PMC8001015 DOI: 10.3390/ijms22062890] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 02/07/2023] Open
Abstract
During its evolution, cancer induces changes in patients’ energy metabolism that strongly affect the overall clinical state and are responsible for cancer-related cachexia syndrome. To better understand the mechanisms underlying cachexia and its metabolic derangements, research efforts should focus on the events that are driven by the immune system activation during the evolution of neoplastic disease and on the phenomena of “resistance” and “tolerance” typically involved in the human body response against stress, pathogens, or cancer. Indeed, in the case where resistance is not able to eliminate the cancer, tolerance mechanisms can utilize the symptoms of cachexia (anemia, anorexia, and fatigue) to counteract unregulated cancer growth. These notions are also sustained by the evidence that cancer cachexia may be reversible if the resistance and tolerance phases are supported by appropriate antineoplastic treatments. Accordingly, there is no doubt that anticachectic therapies have an irreplaceable role in cases of reversible cancer cachexia where, if harmoniously associated with effective antineoplastic therapies, they can contribute to preserve the quality of life and improve prognosis. Such anticachectic treatments should be based on targeting the complex immunological, inflammatory, and metabolic pathways involved in the complex pathogenesis of cachexia. Meanwhile, the role of the anticachectic therapies is very different in the stage of irreversible cachexia when the available antineoplastic treatments are not able to control the disease and the resistance mechanisms fail with the prevalence of the tolerance phenomena. At this stage, they can be useful only to improve the quality of life, allowing the patient and their family to get a better awareness of the final phases of life, thereby opening to the best spiritual remodulation of the final event, death.
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17
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Friedman B, Corciulo C, Castro CM, Cronstein BN. Adenosine A2A receptor signaling promotes FoxO associated autophagy in chondrocytes. Sci Rep 2021; 11:968. [PMID: 33441836 PMCID: PMC7806643 DOI: 10.1038/s41598-020-80244-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 12/11/2020] [Indexed: 01/05/2023] Open
Abstract
Autophagy, a homeostatic pathway upregulated during cellular stress, is decreased in osteoarthritic chondrocytes and this reduction in autophagy is thought to contribute to the development and progression of osteoarthritis (OA). The adenosine A2A receptor (A2AR) is a potent anti-inflammatory receptor and deficiency of this receptor leads to the development of OA in mice. Moreover, treatment using liposomally conjugated adenosine or a specific A2AR agonist improved joint scores significantly in both rats with post-traumatic OA (PTOA) and mice subjected to a high fat diet obesity induced OA. Importantly, A2AR ligation is beneficial for mitochondrial health and metabolism in vitro in primary and the TC28a2 human cell line. An additional set of metabolic, stress-responsive, and homeostatic mediators include the Forkhead box O transcription factors (FoxOs). Data has shown that mouse FoxO knockouts develop early OA with reduced cartilage autophagy, indicating that FoxO-induced homeostasis is important for articular cartilage. Given the apparent similarities between A2AR and FoxO signaling, we tested the hypothesis that A2AR stimulation improves cartilage function through activation of the FoxO proteins leading to increased autophagy in chondrocytes. We analyzed the signaling pathway in the human TC28a2 cell line and corroborated these findings in vivo in a metabolically relevant obesity-induced OA mouse model. We found that A2AR stimulation increases activation and nuclear localization of FoxO1 and FoxO3, promotes an increase in autophagic flux, improves metabolic function in chondrocytes, and reduces markers of apoptosis in vitro and reduced apoptosis by TUNEL assay in vivo. A2AR ligation additionally enhances in vivo activation of FoxO1 and FoxO3 with evidence of enhanced autophagic flux upon injection of the liposome-associated A2AR agonist in a mouse obesity-induced OA model. These findings offer further evidence that A2AR may be an excellent target for promoting chondrocyte and cartilage homeostasis.
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Affiliation(s)
- Benjamin Friedman
- Department of Medicine, Division of Rheumatology, NYU School of Medicine, 550 First Avenue, New York, NY, 10016, USA
- Department of Medicine, Division of Translational Medicine, NYU School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Carmen Corciulo
- Department of Medicine, Division of Translational Medicine, NYU School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Cristina M Castro
- Department of Medicine, Division of Translational Medicine, NYU School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Bruce N Cronstein
- Department of Medicine, Division of Rheumatology, NYU School of Medicine, 550 First Avenue, New York, NY, 10016, USA.
- Department of Medicine, Division of Translational Medicine, NYU School of Medicine, 550 First Avenue, New York, NY, 10016, USA.
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18
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Song Q, He Z, Li B, Liu J, Liu L, Liao W, Xiong Y, Song C, Yang S, Liu Y. Melatonin inhibits oxalate-induced endoplasmic reticulum stress and apoptosis in HK-2 cells by activating the AMPK pathway. Cell Cycle 2020; 19:2600-2610. [PMID: 32871086 DOI: 10.1080/15384101.2020.1810401] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Background: Deposition of various crystal and organic substances in the kidney can lead to kidney stone formation. Melatonin is an effective endogenous antioxidant that can prevent crystalluria and kidney damage due to crystal formation and aggregation. In this study, we investigated the mechanism by which melatonin inhibits endoplasmic reticulum (ER) stress and apoptosis. Methods: We treated HK-2 cells with oxalate to establish an in vitro kidney stone model, and treated these cells with different concentrations of melatonin (0, 5, 10, 20 μmol/L) and the AMP-activated protein kinase (AMPK) inhibitor Compound C. We measured levels of stress response markers including reactive oxygen species (ROS), lactate dehydrogenase (LDH), glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), and factors in the stress response pathway, such as ATF6, GRP78, DDIT3, PERK, p-PERK, IRE1, p-IRE1, XBP1s, AMPK, and p-AMPK, using real time-PCR, western blot, and immunofluorescence analyzes. We measured mitochondrial membrane potential and caspases-3 activity using the CCK8, enzyme-linked immunosorbent, and flow cytometry assays to assess HK-2 cell viability and apoptosis. Results: Melatonin improved the total antioxidant capacity (T-AOC) of the HK-2 cells, as evidenced by the dose-dependent reduction in apoptosis, ROS levels, and protein expression of ATF6, GRP78, DDIT3, p-PERK, p-IRE1, XBP1s, caspase-12, cleaved caspase-3 and cleaved caspase-9. Addition of the AMPK inhibitor, Compound C, partially reversed the protective effect of melatonin. Conclusion: Our study revealed that the protective effects of melatonin on oxalate-induced ER stress and apoptosis is partly dependent on AMPK activation in HK-2 cells. These findings provide insight into the prevention and treatment of kidney stones.
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Affiliation(s)
- Qianlin Song
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Ziqi He
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Bin Li
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Junwei Liu
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Lang Liu
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Wenbiao Liao
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Yunhe Xiong
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Chao Song
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Sixing Yang
- Department of Urology, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
| | - Yunlong Liu
- Department of Urology, The First Affiliated Hospital of Zhengzhou University , Zhengzhou, Henan, People's Republic of China
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19
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Peake JM, Markworth JF, Cumming KT, Aas SN, Roberts LA, Raastad T, Cameron-Smith D, Figueiredo VC. The Effects of Cold Water Immersion and Active Recovery on Molecular Factors That Regulate Growth and Remodeling of Skeletal Muscle After Resistance Exercise. Front Physiol 2020; 11:737. [PMID: 32695024 PMCID: PMC7339943 DOI: 10.3389/fphys.2020.00737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 06/08/2020] [Indexed: 01/16/2023] Open
Abstract
Regular postexercise cooling attenuates muscle hypertrophy, yet its effects on the key molecular factors that regulate muscle growth and remodeling are not well characterized. In the present study, nine men completed two sessions of single-leg resistance exercise on separate days. On 1 day, they sat in cold water (10°C) up to their waist for 10 min after exercise. On the other day, they exercised at a low intensity for 10 min after exercise. Muscle biopsies were collected from the exercised leg before, 2, 24, and 48 h after exercise in both trials. These muscle samples were analyzed to evaluate changes in genes and proteins involved in muscle growth and remodeling. Muscle-specific RING finger 1 mRNA increased at 2 h after both trials (P < 0.05), while insulin-like growth factor (IGF)-1 Ec, IGF-1 receptor, growth arrest and DNA damage-inducible protein 45, collagen type I alpha chain A, collagen type III alpha chain 1, laminin and tissue inhibitor of metallopeptidase 1 mRNA increased 24−48 h after both trials (P < 0.05). By contrast, atrogin-1 mRNA decreased at all time points after both trials (P < 0.05). Protein expression of tenascin C increased 2 h after the active recovery trial (P < 0.05), whereas FoxO3a protein expression decreased after both trials (P < 0.05). Myostatin mRNA and ubiquitin protein expression did not change after either trial. These responses were not significantly different between the trials. The present findings suggest that regular cold water immersion attenuates muscle hypertrophy independently of changes in factors that regulate myogenesis, proteolysis and extracellular matrix remodeling in muscle after exercise.
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Affiliation(s)
- Jonathan M Peake
- Queensland University of Technology, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Brisbane, QLD, Australia.,Sport Performance Innovation and Knowledge Excellence, Queensland Academy of Sport, Brisbane, QLD, Australia
| | - James F Markworth
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | | | - Sigve N Aas
- Norwegian School of Sport Sciences, Oslo, Norway
| | - Llion A Roberts
- Sport Performance Innovation and Knowledge Excellence, Queensland Academy of Sport, Brisbane, QLD, Australia.,School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD, Australia.,School of Allied Health Sciences, Griffith University, Southport, QLD, Australia
| | | | - David Cameron-Smith
- Agency for Science, Technology and Research (A∗STAR), Brenner Centre for Molecular Medicine, Singapore, Singapore
| | - Vandre C Figueiredo
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,Center for Muscle Biology, University of Kentucky, Lexington, KY, United States
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20
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Wagatsuma A, Arakawa M, Matsumoto H, Matsuda R, Hoshino T, Mabuchi K. Cobalt chloride, a chemical hypoxia-mimicking agent, suppresses myoblast differentiation by downregulating myogenin expression. Mol Cell Biochem 2020; 470:199-214. [PMID: 32451753 DOI: 10.1007/s11010-020-03762-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 05/16/2020] [Indexed: 12/17/2022]
Abstract
Cobalt chloride can create hypoxia-like state in vitro (referred to as chemical hypoxia). Several studies have suggested that chemical hypoxia may cause deleterious effects on myogenesis. The intrinsic underlying mechanisms of myoblast differentiation, however, are not fully understood. Here, we show that cobalt chloride strongly suppresses myoblast differentiation in a dose-dependent manner. The impaired myoblast differentiation is accompanied by downregulation of myogenic regulatory factor myogenin. Under chemical hypoxia, myogenin stability is decreased at mRNA and protein levels. A muscle-specific E3 ubiquitin ligase MAFbx, which can target myogenin protein for proteasomal degradation, is upregulated along with changes in Akt/Foxo and AMPK/Foxo signaling pathways. A proteasome inhibitor completely prevents cobalt chloride-mediated decrease in myogenin protein. These results suggest that cobalt chloride might modulate myogenin expression at post-transcriptional and post-translational levels, resulting in the failure of the myoblasts to differentiate into myotubes.
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Affiliation(s)
- Akira Wagatsuma
- Department of Information Physics and Computing, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan.
- Department of Communication, Tokyo Women's Christian University, Tokyo, Japan.
| | - Masayuki Arakawa
- Institute of Microbial Chemistry, Biology Division, Laboratory of Virology, Tokyo, Japan
| | - Hanano Matsumoto
- Department of Food and Health Science, Faculty of Human Life Sciences, Jissen Women's University, Tokyo, Japan
| | - Ryoichi Matsuda
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Takayuki Hoshino
- Department of Information Physics and Computing, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kunihiko Mabuchi
- Department of Information Physics and Computing, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
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21
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Phosphoproteomics identifies dual-site phosphorylation in an extended basophilic motif regulating FILIP1-mediated degradation of filamin-C. Commun Biol 2020; 3:253. [PMID: 32444788 PMCID: PMC7244511 DOI: 10.1038/s42003-020-0982-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/01/2020] [Indexed: 01/10/2023] Open
Abstract
The PI3K/Akt pathway promotes skeletal muscle growth and myogenic differentiation. Although its importance in skeletal muscle biology is well documented, many of its substrates remain to be identified. We here studied PI3K/Akt signaling in contracting skeletal muscle cells by quantitative phosphoproteomics. We identified the extended basophilic phosphosite motif RxRxxp[S/T]xxp[S/T] in various proteins including filamin-C (FLNc). Importantly, this extended motif, located in a unique insert in Ig-like domain 20 of FLNc, is doubly phosphorylated. The protein kinases responsible for this dual-site phosphorylation are Akt and PKCα. Proximity proteomics and interaction analysis identified filamin A-interacting protein 1 (FILIP1) as direct FLNc binding partner. FILIP1 binding induces filamin degradation, thereby negatively regulating its function. Here, dual-site phosphorylation of FLNc not only reduces FILIP1 binding, providing a mechanism to shield FLNc from FILIP1-mediated degradation, but also enables fast dynamics of FLNc necessary for its function as signaling adaptor in cross-striated muscle cells. Reimann, Schwäble et al. perform quantitative proteomics to study PI3K/Akt signaling in contracting myotubes. They identify a dual-site phosphorylation motif in the actin cross-linker and signaling adaptor filamin C, which regulates its degradation and mobility, suggesting the importance of dual phosphorylation for filamin C function in striated muscle cells.
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Møller AB, Vendelbo MH, Schjerling P, Couppé C, Møller N, Kjær M, Hansen M, Jessen N. Immobilization Decreases FOXO3a Phosphorylation and Increases Autophagy-Related Gene and Protein Expression in Human Skeletal Muscle. Front Physiol 2019; 10:736. [PMID: 31258486 PMCID: PMC6587099 DOI: 10.3389/fphys.2019.00736] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/27/2019] [Indexed: 01/07/2023] Open
Abstract
Immobilization of the lower limbs promotes a catabolic state that reduces muscle mass, whereas physical training promotes an anabolic state that increases muscle mass. Understanding the molecular mechanisms underlying this is of clinical interest, as loss of muscle mass is a major complication to critical illness in humans. To determine the molecular regulation of protein synthesis and degradation during muscle loss and hypertrophy, we examined skeletal muscle biopsies from healthy human subjects after 2 weeks unilateral immobilization of a lower limb and during 6 weeks of physical rehabilitation. We have previously shown that cross-sectional area of the knee muscle-extensors decreased by ∼10% during immobilization and was completely restored during rehabilitation. Here we provide novel data to suggest that autophagy is an important underlying mechanism involved in regulation of muscle mass. Protein expression of MuRF1 and ATROGIN-1 did not change during the study, indicating that the recruitment of substrates to the proteasomes was unaltered. Phosphorylation of mTORat Ser2448 did not change during the study, and neither did phosphorylation of the mTORC1 substrates 4EBP1 Thr37/46 and p70S6K Thr389, suggesting that this pathway does not suppress protein synthesis during muscle wasting. Protein levels of p62 and ULK1 increased during immobilization and returned to baseline levels during rehabilitation. Same pattern was observed for FOXO3a phosphorylation at Ser318/321, suggesting transcriptional activation during immobilization and inactivation during rehabilitation. To investigate this further, we analyzed mRNA expression of seven autophagy-related genes controlled by FOXO3a. Five of these (p62, LC3B, BECLIN-1, ATG12, and BNIP3) increased during immobilization and returned to baseline during rehabilitation. In conclusion, immobilization of a lower limb increases autophagy-related gene and protein expression in human skeletal muscle in a pattern that mirrors FOXO3a phosphorylation. These findings could imply that FOXO3a dependent transcriptional regulation of autophagy is involved in the regulation of muscle mass in humans.
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Affiliation(s)
- Andreas Buch Møller
- Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University, Aarhus, Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Mikkel Holm Vendelbo
- Department of Nuclear Medicine & PET-Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Peter Schjerling
- Department of Orthopaedic Surgery M, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, Institute of Sports Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Christian Couppé
- Department of Orthopaedic Surgery M, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, Institute of Sports Medicine, University of Copenhagen, Copenhagen, Denmark.,Musculoskeletal Rehabilitation Research Unit, Department of Physical Therapy, Bispebjerg Hospital, Copenhagen, Denmark
| | - Niels Møller
- Medical Research Laboratory, Institute for Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Michael Kjær
- Department of Orthopaedic Surgery M, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, Institute of Sports Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mette Hansen
- Department of Orthopaedic Surgery M, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, Institute of Sports Medicine, University of Copenhagen, Copenhagen, Denmark.,Section of Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University, Aarhus, Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
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23
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Recent Data on Cellular Component Turnover: Focus on Adaptations to Physical Exercise. Cells 2019; 8:cells8060542. [PMID: 31195688 PMCID: PMC6627613 DOI: 10.3390/cells8060542] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/31/2019] [Accepted: 06/02/2019] [Indexed: 12/22/2022] Open
Abstract
Significant progress has expanded our knowledge of the signaling pathways coordinating muscle protein turnover during various conditions including exercise. In this manuscript, the multiple mechanisms that govern the turnover of cellular components are reviewed, and their overall roles in adaptations to exercise training are discussed. Recent studies have highlighted the central role of the energy sensor (AMP)-activated protein kinase (AMPK), forkhead box class O subfamily protein (FOXO) transcription factors and the kinase mechanistic (or mammalian) target of rapamycin complex (MTOR) in the regulation of autophagy for organelle maintenance during exercise. A new cellular trafficking involving the lysosome was also revealed for full activation of MTOR and protein synthesis during recovery. Other emerging candidates have been found to be relevant in organelle turnover, especially Parkin and the mitochondrial E3 ubiquitin protein ligase (Mul1) pathways for mitochondrial turnover, and the glycerolipids diacylglycerol (DAG) for protein translation and FOXO regulation. Recent experiments with autophagy and mitophagy flux assessment have also provided important insights concerning mitochondrial turnover during ageing and chronic exercise. However, data in humans are often controversial and further investigations are needed to clarify the involvement of autophagy in exercise performed with additional stresses, such as hypoxia, and to understand the influence of exercise modality. Improving our knowledge of these pathways should help develop therapeutic ways to counteract muscle disorders in pathological conditions.
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24
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Møller AB, Lønbro S, Farup J, Voss TS, Rittig N, Wang J, Højris I, Mikkelsen UR, Jessen N. Molecular and cellular adaptations to exercise training in skeletal muscle from cancer patients treated with chemotherapy. J Cancer Res Clin Oncol 2019; 145:1449-1460. [PMID: 30968255 DOI: 10.1007/s00432-019-02911-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 03/28/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND A growing body of evidence suggests that exercise training has beneficial effects in cancer patients. The aim of the present study was to investigate the molecular basis underlying these beneficial effects in skeletal muscle from cancer patients. METHODS We investigated expression of selected proteins involved in cellular processes known to orchestrate adaptation to exercise training by western blot. Skeletal muscle biopsies were sampled from ten cancer patients before and after 4-7 weeks of ongoing chemotherapy, and subsequently after 10 weeks of continued chemotherapy in combination with exercise training. Biopsies from ten healthy matched subjects served as reference. RESULTS The expression of the insulin-regulated glucose transporter, GLUT4, increased during chemotherapy and continued to increase during exercise training. A similar trend was observed for ACC, a key enzyme in the biosynthesis and oxidation of fatty acids, but we did not observe any changes in other regulators of substrate metabolism (AMPK and PDH) or mitochondrial proteins (Cyt-C, COX-IV, SDHA, and VDAC). Markers of proteasomal proteolysis (MURF1 and ATROGIN-1) decreased during chemotherapy, but did not change further during chemotherapy combined with exercise training. A similar pattern was observed for autophagy-related proteins such as ATG5, p62, and pULK1 Ser757, but not ULK1 and LC3BII/LC3BI. Phosphorylation of FOXO3a at Ser318/321 did not change during chemotherapy, but decreased during exercise training. This could suggest that FOXO3a-mediated transcriptional regulation of MURF1 and ATROGIN-1 serves as a mechanism by which exercise training maintains proteolytic systems in skeletal muscle in cancer patients. Phosphorylation of proteins that regulate protein synthesis (mTOR at Ser2448 and 4EBP1 at Thr37/46) increased during chemotherapy and leveled off during exercise training. Finally, chemotherapy tended to increase the number of satellite cells in type 1 fibers, without any further change during chemotherapy and exercise training. Conversely, the number of satellite cells in type 2 fibers did not change during chemotherapy, but increased during chemotherapy combined with exercise training. CONCLUSIONS Molecular signaling cascades involved in exercise training are disturbed during cancer and chemotherapy, and exercise training may prevent further disruption of these pathways. TRIAL REGISTRATION The study was approved by the local Scientific Ethics Committee of the Central Denmark Region (Project ID: M-2014-15-14; date of approval: 01/27/2014) and the Danish Data Protection Agency (case number 2007-58-0010; date of approval: 01/28/2015). The trial was registered at http//www.clinicaltrials.gov (registration number: NCT02192216; date of registration 07/17-2014).
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Affiliation(s)
- Andreas Buch Møller
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, HEALTH, Aarhus University Hospital, Palle Juul-Jensen Blvd., 8200, Aarhus N, Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Simon Lønbro
- Section of Sports Science, Department of Public Health, HEALTH, Aarhus University, Aarhus, Denmark.,Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Jean Farup
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, HEALTH, Aarhus University Hospital, Palle Juul-Jensen Blvd., 8200, Aarhus N, Denmark
| | - Thomas Schmidt Voss
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratory, Department of Clinical Medicine, HEALTH, Aarhus University, Aarhus, Denmark
| | - Nikolaj Rittig
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratory, Department of Clinical Medicine, HEALTH, Aarhus University, Aarhus, Denmark
| | - Jakob Wang
- Section of Sports Science, Department of Public Health, HEALTH, Aarhus University, Aarhus, Denmark
| | - Inger Højris
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Ulla Ramer Mikkelsen
- Section of Sports Science, Department of Public Health, HEALTH, Aarhus University, Aarhus, Denmark.,Department of Orthopedic Surgery, Bispebjerg Hospital and Center for Healthy Aging, Institute of Sports Medicine, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, HEALTH, Aarhus University Hospital, Palle Juul-Jensen Blvd., 8200, Aarhus N, Denmark. .,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark. .,Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus, Denmark.
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25
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Lynch GS, Koopman R. Overcoming nature’s paradox in skeletal muscle to optimise animal production. ANIMAL PRODUCTION SCIENCE 2019. [DOI: 10.1071/an19361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Nature’s paradox in skeletal muscle describes the seemingly mutually exclusive relationship between muscle fibre size and oxidative capacity. In mammals, there is a constraint on the size at which mitochondria-rich, high O2-dependent oxidative fibres can attain before they become anoxic or adapt to a glycolytic phenotype, being less reliant on O2. This implies that a muscle fibre can hypertrophy at the expense of its endurance capacity. Adaptations to activity (exercise) generally obey this relationship, with optimal muscle endurance generally being linked to an enhanced proportion of small, slow oxidative fibres and muscle strength (force and/or power) being linked to an enhanced proportion of large, fast glycolytic fibres. This relationship generally constrains not only the physiological limits of performance (e.g. speed and endurance), but also the capacity to manipulate muscle attributes such as fibre size and composition, with important relevance to the livestock and aquaculture industries for producing specific muscle traits such as (flesh) quality, texture and taste. Highly glycolytic (white) muscles have different traits than do highly oxidative (red) muscles and so the ability to manipulate muscle attributes to produce flesh with specific traits has important implications for optimising meat production and quality. Understanding the biological regulation of muscle size, and phenotype and the capacity to manipulate signalling pathways to produce specific attributes, has important implications for promoting ethically sustainable and profitable commercial livestock and aquaculture practices and for developing alternative food sources, including ‘laboratory meat’ or ‘clean meat’. This review describes the exciting potential of manipulating muscle attributes relevant to animal production, through traditional nutritional and pharmacological approaches and through viral-mediated strategies that could theoretically push the limits of muscle fibre growth, adaptation and plasticity.
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26
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Hyatt H, Deminice R, Yoshihara T, Powers SK. Mitochondrial dysfunction induces muscle atrophy during prolonged inactivity: A review of the causes and effects. Arch Biochem Biophys 2018; 662:49-60. [PMID: 30452895 DOI: 10.1016/j.abb.2018.11.005] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 11/05/2018] [Indexed: 02/08/2023]
Abstract
Prolonged skeletal muscle inactivity (e.g. limb immobilization, bed rest, mechanical ventilation, spinal cord injury, etc.) results in muscle atrophy that manifests into a decreased quality of life and in select patient populations, a higher risk of morbidity and mortality. Thus, understanding the processes that contribute to muscle atrophy during prolonged periods of muscle disuse is an important area of research. In this regard, mitochondrial dysfunction has been directly linked to the muscle wasting that occurs during extended periods of skeletal muscle inactivity. While the concept that mitochondrial dysfunction contributes to disuse muscle atrophy has been contemplated for nearly 50 years, the mechanisms connecting mitochondrial signaling events to skeletal muscle atrophy remained largely unexplained until recently. Indeed, emerging evidence reveals that mitochondrial dysfunction and the associated mitochondrial signaling events are a requirement for several forms of inactivity-induced skeletal muscle atrophy. Specifically, inactivity-induced alterations in skeletal muscle mitochondria phenotype and increased ROS emission, impaired Ca2+ handling, and release of mitochondria-specific proteolytic activators are established occurrences that promote fiber atrophy during prolonged periods of muscle inactivity. This review highlights the evidence that directly connects mitochondrial dysfunction and aberrant mitochondrial signaling with skeletal muscle atrophy and discusses the mechanisms linking these interconnected phenomena.
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Affiliation(s)
- Hayden Hyatt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
| | - Rafael Deminice
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Department of Physical Education, University of Estadual of Londrina, Londrina, Brazil
| | - Toshinori Yoshihara
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Department of Exercise Physiology, Juntendo University, Tokyo, Japan
| | - Scott K Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
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27
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Sanchez AMJ, Candau R, Bernardi H. AMP-activated protein kinase stabilizes FOXO3 in primary myotubes. Biochem Biophys Res Commun 2018; 499:493-498. [PMID: 29580989 DOI: 10.1016/j.bbrc.2018.03.176] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 03/22/2018] [Indexed: 01/01/2023]
Abstract
AMP-activated protein kinase (AMPK) is a critical enzyme in conditions of cellular energy deficit such as exercise, hypoxia or nutritional stress. AMPK is well known to regulate protein degradation pathways notably through FOXO-related axis. In this study, we investigated the implication of AMPK activation in FOXO3 expression and stability in skeletal muscle primary myotubes. First, time course and dose response studies revealed optimal AICAR treatment duration and dose in skeletal muscle cells. Then, experiments with cycloheximide treatment of primary myotubes highlighted that AICAR infusion extends FOXO3 protein half-life. Our results also showed that AICAR treatment or nutrient depletion increases FOXO3 expression in primary myotubes and the expression of the mitochondrial E3 ligase Mul1 involved in mitochondrial turnover (mitophagy). In AMPK KO cells, nutrient depletion failed to alter the level of some FOXO3-dependent atrophic genes, including LC3B, BNIP3, and the mitochondrial E3 ligase Mul1, but not the expression of other genes (i.e. FOXO1, Gabarapl1, MAFbx, MuRF1). In summary, our data highlight that AMPK stabilizes FOXO3 and suggest a role in the first initiation step of mitochondrial segregation in muscle cells.
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Affiliation(s)
- Anthony M J Sanchez
- University of Perpignan Via Domitia, Laboratoire Européen Performance Santé Altitude (LEPSA), EA4604, Department of Sports Sciences, 7 avenue Pierre de Coubertin, 66120 Font-Romeu, France.
| | - Robin Candau
- Faculty of Sports Science, University of Montpellier, 700 avenue du Pic Saint Loup, 34090 Montpellier, France; INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier, 2 Place Viala, 34060 Montpellier, France
| | - Henri Bernardi
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier, 2 Place Viala, 34060 Montpellier, France
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28
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Abstract
This article reviews current treatment strategies and recent advances for the Lewy body dementias (LBDs). Current available symptom treatment strategies are based on monoaminergic, cholinergic and glutaminergic neurotransmitter systems. Relatively robust evidence exists for cholinesterase inhibitors for cognitive impairment in LBD and in Parkinson's disease for antidepressants, clozapine and recently pimavanserin for psychosis. interpidine (RVT 101) and nelotanserin are currently under investigation. Non-pharmacological interventions, such as cognitive stimulation, physical exercises and neuromodulation strategies, may be useful in Parkinson's disease but have not yet been tested in dementias. Disease-modifying approaches are aimed at preventing, slowing or ameliorating the production, aggregation and deposition of pathological proteins, including immunotherapy targeting α-synuclein and an ongoing trial using ambroxol which increases glucocerebrosidase activity to lower the levels of the protein alpha-synuclein. Other disease-modifying clinical trials are using agents to augment insulin signalling, stem cell therapy, reducing amyloid pathology and gene therapy.
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29
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Abstract
A substantial loss of muscle mass and strength (sarcopenia), a decreased regenerative capacity, and a compromised physical performance are hallmarks of aging skeletal muscle. These changes are typically accompanied by impaired muscle metabolism, including mitochondrial dysfunction and insulin resistance. A challenge in the field of muscle aging is to dissociate the effects of chronological aging per se on muscle characteristics from the secondary influence of lifestyle and disease processes. Remarkably, physical activity and exercise are well-established countermeasures against muscle aging, and have been shown to attenuate age-related decreases in muscle mass, strength, and regenerative capacity, and slow or prevent impairments in muscle metabolism. We posit that exercise and physical activity can influence many of the changes in muscle during aging, and thus should be emphasized as part of a lifestyle essential to healthy aging.
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Affiliation(s)
- Giovanna Distefano
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, Florida 32804
| | - Bret H Goodpaster
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, Florida 32804
- Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827
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30
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van den Berg M, Hooijman PE, Beishuizen A, de Waard MC, Paul MA, Hartemink KJ, van Hees HWH, Lawlor MW, Brocca L, Bottinelli R, Pellegrino MA, Stienen GJM, Heunks LMA, Wüst RCI, Ottenheijm CAC. Diaphragm Atrophy and Weakness in the Absence of Mitochondrial Dysfunction in the Critically Ill. Am J Respir Crit Care Med 2017; 196:1544-1558. [PMID: 28787181 DOI: 10.1164/rccm.201703-0501oc] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
RATIONALE The clinical significance of diaphragm weakness in critically ill patients is evident: it prolongs ventilator dependency and increases morbidity, duration of hospital stay, and health care costs. The mechanisms underlying diaphragm weakness are unknown, but might include mitochondrial dysfunction and oxidative stress. OBJECTIVES We hypothesized that weakness of diaphragm muscle fibers in critically ill patients is accompanied by impaired mitochondrial function and structure, and by increased markers of oxidative stress. METHODS To test these hypotheses, we studied contractile force, mitochondrial function, and mitochondrial structure in diaphragm muscle fibers. Fibers were isolated from diaphragm biopsies of 36 mechanically ventilated critically ill patients and compared with those isolated from biopsies of 27 patients with suspected early-stage lung malignancy (control subjects). MEASUREMENTS AND MAIN RESULTS Diaphragm muscle fibers from critically ill patients displayed significant atrophy and contractile weakness, but lacked impaired mitochondrial respiration and increased levels of oxidative stress markers. Mitochondrial energy status and morphology were not altered, despite a lower content of fusion proteins. CONCLUSIONS Critically ill patients have manifest diaphragm muscle fiber atrophy and weakness in the absence of mitochondrial dysfunction and oxidative stress. Thus, mitochondrial dysfunction and oxidative stress do not play a causative role in the development of atrophy and contractile weakness of the diaphragm in critically ill patients.
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Affiliation(s)
| | | | - Albertus Beishuizen
- 2 Department of Intensive Care, Medisch Spectrum Twente, Enschede, the Netherlands
| | | | - Marinus A Paul
- 4 Department of Cardiothoracic Surgery, Vrije Universiteit (VU) University Medical Center, Amsterdam, the Netherlands
| | - Koen J Hartemink
- 5 Department of Surgery, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands
| | | | - Michael W Lawlor
- 7 Division of Pediatric Pathology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | | | - Roberto Bottinelli
- 8 Department of Molecular Medicine.,10 Interdepartmental Center for Biology and Sport Medicine, and.,9 Fondazione Salvatore Maugeri (IRCCS), Scientific Institute of Pavia, Pavia, Italy
| | - Maria A Pellegrino
- 8 Department of Molecular Medicine.,10 Interdepartmental Center for Biology and Sport Medicine, and.,11 Interuniversity Institute of Myology, University of Pavia, Pavia, Italy
| | - Ger J M Stienen
- 1 Department of Physiology, Amsterdam Cardiovascular Sciences.,12 Faculty of Science, Department of Physics and Astronomy, VU Amsterdam, Amsterdam, the Netherlands
| | | | - Rob C I Wüst
- 1 Department of Physiology, Amsterdam Cardiovascular Sciences.,13 Laboratory Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, the Netherlands; and
| | - Coen A C Ottenheijm
- 1 Department of Physiology, Amsterdam Cardiovascular Sciences.,14 Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona
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31
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Linking Cancer Cachexia-Induced Anabolic Resistance to Skeletal Muscle Oxidative Metabolism. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:8018197. [PMID: 29375734 PMCID: PMC5742498 DOI: 10.1155/2017/8018197] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 11/06/2017] [Indexed: 01/03/2023]
Abstract
Cancer cachexia, a wasting syndrome characterized by skeletal muscle depletion, contributes to increased patient morbidity and mortality. While the intricate balance between protein synthesis and breakdown regulates skeletal muscle mass, the suppression of basal protein synthesis may not account for the severe wasting induced by cancer. Therefore, recent research has shifted to the regulation of “anabolic resistance,” which is the impaired ability of nutrition and exercise to stimulate protein synthesis. Emerging evidence suggests that oxidative metabolism can regulate both basal and induced muscle protein synthesis. While disrupted protein turnover and oxidative metabolism in cachectic muscle have been examined independently, evidence suggests a linkage between these processes for the regulation of cancer-induced wasting. The primary objective of this review is to highlight the connection between dysfunctional oxidative metabolism and cancer-induced anabolic resistance in skeletal muscle. First, we review oxidative metabolism regulation of muscle protein synthesis. Second, we describe cancer-induced alterations in the response to an anabolic stimulus. Finally, we review a role for exercise to inhibit cancer-induced anabolic suppression and mitochondrial dysfunction.
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32
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White DP, Baumgarner BL, Watanabe WO, Alam MS, Kinsey ST. The effects of dietary β-guanidinopropionic acid on growth and muscle fiber development in juvenile red porgy, Pagrus pagrus. Comp Biochem Physiol B Biochem Mol Biol 2017; 216:48-58. [PMID: 29175483 DOI: 10.1016/j.cbpb.2017.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/10/2017] [Accepted: 11/17/2017] [Indexed: 02/07/2023]
Abstract
β-guanidinopropionic acid (β-GPA) has been used in mammalian models to reduce intracellular phosphocreatine (PCr) concentration, which in turn lowers the energetic state of cells. This leads to changes in signaling pathways that attempt to re-establish energetic homeostasis. Changes in those pathways elicit effects similar to those of exercise such as changes in body and muscle growth, metabolism, endurance and health. Generally, exercise effects are beneficial to fish health and aquaculture, but inducing exercise in fishes can be impractical. Therefore, this study evaluated the potential use of supplemental β-GPA to induce exercise-like effects in a rapidly growing juvenile teleost, the red porgy (Pagrus pagrus). We demonstrate for the first time that β-GPA can be transported into teleost muscle fibers and is phosphorylated, and that this perturbs the intracellular energetic state of the cells, although to a lesser degree than typically seen in mammals. β-GPA did not affect whole animal growth, nor did it influence skeletal muscle fiber size or myonuclear recruitment. There was, however, an increase in mitochondrial volume within myofibers in treated fish. GC/MS metabolomic analysis revealed shifts in amino acid composition of the musculature, putatively reflecting increases in connective tissue and decreases in protein synthesis that are associated with β-GPA treatment. These results suggest that β-GPA modestly affects fish muscle in a manner similar to that observed in mammals, and that β-GPA may have application to aquaculture by providing a more practical means of generating some of the beneficial effects of exercise in fishes.
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Affiliation(s)
- Dalon P White
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403-5915, United States.
| | - Bradley L Baumgarner
- Division of Natural Sciences and Engineering, University of South Carolina Upstate, 800 University Way, Spartanburg, SC 29303, United States
| | - Wade O Watanabe
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403-5915, United States; Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28403-5928, United States
| | - Md Shah Alam
- Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28403-5928, United States
| | - Stephen T Kinsey
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403-5915, United States
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Paré MF, Jasmin BJ. Chronic 5-Aminoimidazole-4-Carboxamide-1-β-d-Ribofuranoside Treatment Induces Phenotypic Changes in Skeletal Muscle, but Does Not Improve Disease Outcomes in the R6/2 Mouse Model of Huntington's Disease. Front Neurol 2017; 8:516. [PMID: 29021780 PMCID: PMC5623671 DOI: 10.3389/fneur.2017.00516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/14/2017] [Indexed: 12/29/2022] Open
Abstract
Huntington’s disease (HD) is an autosomal dominant neurodegenerative genetic disorder characterized by motor, cognitive, and psychiatric symptoms. It is well established that regular physical activity supports brain health, benefiting cognitive function, mental health as well as brain structure and plasticity. Exercise mimetics (EMs) are a group of drugs and small molecules that target signaling pathways in skeletal muscle known to be activated by endurance exercise. The EM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) has been shown to induce cognitive benefits in healthy mice. Since AICAR does not readily cross the blood–brain barrier, its beneficial effect on the brain has been ascribed to its impact on skeletal muscle. Our objective, therefore, was to examine the effect of chronic AICAR treatment on the muscular and neurological pathology in a mouse model of HD. To this end, R6/2 mice were treated with AICAR for 8 weeks and underwent regular neurobehavioral testing. Under our conditions, AICAR increased expression of PGC-1α, a powerful phenotypic modifier of muscle, and induced the expected shift toward a more oxidative muscle phenotype in R6/2 mice. However, this treatment failed to induce benefits on HD progression. Indeed, neurobehavioral deficits, striatal, and muscle mutant huntingtin aggregate density, as well as muscle atrophy were not mitigated by the chronic administration of AICAR. Although the muscle adaptations seen in HD mice following AICAR treatment may still provide therapeutically relevant benefits to patients with limited mobility, our findings indicate that under our experimental conditions, AICAR had no effect on several hallmarks of HD.
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Affiliation(s)
- Marie-France Paré
- Faculty of Medicine, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Bernard J Jasmin
- Faculty of Medicine, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
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Li F, Li X, Peng X, Sun L, Jia S, Wang P, Ma S, Zhao H, Yu Q, Huo H. Ginsenoside Rg1 prevents starvation-induced muscle protein degradation via regulation of AKT/mTOR/FoxO signaling in C2C12 myotubes. Exp Ther Med 2017; 14:1241-1247. [PMID: 28781621 DOI: 10.3892/etm.2017.4615] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/19/2016] [Indexed: 01/07/2023] Open
Abstract
Skeletal muscle atrophy is often caused by catabolic conditions including fasting, disuse, aging and chronic diseases, such as chronic obstructive pulmonary disease. Atrophy occurs when the protein degradation rate exceeds the rate of protein synthesis. Therefore, maintaining a balance between the synthesis and degradation of protein in muscle cells is a major way to prevent skeletal muscle atrophy. Ginsenoside Rg1 (Rg1) is a primary active ingredient in Panax ginseng, which is considered to be one of the most valuable herbs in traditional Chinese medicine. In the current study, Rg1 was observed to inhibit the expression of MuRF-1 and atrogin-1 in C2C12 muscle cells in a starvation model. Rg1 also activated the phosphorylation of mammalian target of rapamycin (mTOR), protein kinase B (AKT), and forkhead transcription factor O, subtypes 1 and 3a. This phosphorylation was inhibited by LY294002, a phosphatidylinositol 3-kinase inhibitor. These data suggest that Rg1 may participate in the regulation of the balance between protein synthesis and degradation, and that the function of Rg1 is associated with the AKT/mTOR/FoxO signaling pathway.
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Affiliation(s)
- Fengyu Li
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Xiaoxue Li
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Xuewei Peng
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Lili Sun
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Shengnan Jia
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Ping Wang
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Shuang Ma
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Hongyan Zhao
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Qingmiao Yu
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
| | - Hongliang Huo
- Laboratory of Molecular and Cellular Physiology, School of Life Science, Northeast Normal University, Changchun, Jilin 130024, P.R. China
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Hughes MA, Downs RM, Webb GW, Crocker CL, Kinsey ST, Baumgarner BL. Acute high-caffeine exposure increases autophagic flux and reduces protein synthesis in C2C12 skeletal myotubes. J Muscle Res Cell Motil 2017; 38:201-214. [PMID: 28634643 PMCID: PMC5660649 DOI: 10.1007/s10974-017-9473-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/06/2017] [Indexed: 11/30/2022]
Abstract
Caffeine is a highly catabolic dietary stimulant. High caffeine concentrations (1-10 mM) have previously been shown to inhibit protein synthesis and increase protein degradation in various mammalian cell lines. The purpose of this study was to examine the effect of short-term caffeine exposure on cell signaling pathways that regulate protein metabolism in mammalian skeletal muscle cells. Fully differentiated C2C12 skeletal myotubes either received vehicle (DMSO) or 5 mM caffeine for 6 h. Our analysis revealed that caffeine promoted a 40% increase in autolysosome formation and a 25% increase in autophagic flux. In contrast, caffeine treatment did not significantly increase the expression of the skeletal muscle specific ubiquitin ligases MAFbx and MuRF1 or 20S proteasome activity. Caffeine treatment significantly reduced mTORC1 signaling, total protein synthesis and myotube diameter in a CaMKKβ/AMPK-dependent manner. Further, caffeine promoted a CaMKII-dependent increase in myostatin mRNA expression that did not significantly contribute to the caffeine-dependent reduction in protein synthesis. Our results indicate that short-term caffeine exposure significantly reduced skeletal myotube diameter by increasing autophagic flux and promoting a CaMKKβ/AMPK-dependent reduction in protein synthesis.
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Affiliation(s)
- M A Hughes
- Division of Natural Sciences and Engineering, University of South Carolina Upstate, Spartanburg, SC, 29303, USA
| | - R M Downs
- Division of Natural Sciences and Engineering, University of South Carolina Upstate, Spartanburg, SC, 29303, USA
| | - G W Webb
- Division of Natural Sciences and Engineering, University of South Carolina Upstate, Spartanburg, SC, 29303, USA
| | - C L Crocker
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, 28403-5915, USA
| | - S T Kinsey
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, 28403-5915, USA
| | - Bradley L Baumgarner
- Division of Natural Sciences and Engineering, University of South Carolina Upstate, Spartanburg, SC, 29303, USA.
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Møller AB, Kampmann U, Hedegaard J, Thorsen K, Nordentoft I, Vendelbo MH, Møller N, Jessen N. Altered gene expression and repressed markers of autophagy in skeletal muscle of insulin resistant patients with type 2 diabetes. Sci Rep 2017; 7:43775. [PMID: 28252104 PMCID: PMC5333153 DOI: 10.1038/srep43775] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/30/2017] [Indexed: 12/15/2022] Open
Abstract
This case-control study was designed to investigate the gene expression profile in skeletal muscle from severely insulin resistant patients with long-standing type 2 diabetes (T2D), and to determine associated signaling pathways. Gene expression profiles were examined by whole transcriptome, strand-specific RNA-sequencing and associated signaling was determined by western blot. We identified 117 differentially expressed gene transcripts. Ingenuity Pathway Analysis related these differences to abnormal muscle morphology and mitochondrial dysfunction. Despite a ~5-fold difference in plasma insulin, we did not observe any difference in phosphorylation of AKT or AS160, although other insulin-sensitive cascades, as mTOR/4EBP1, had retained their sensitivity. Autophagy-related gene (ATG14, RB1CC1/FIP200, GABARAPL1, SQSTM1/p62, and WIPI1) and protein (LC3BII, SQSTM1/p62 and ATG5) expression were decreased in skeletal muscle from the patients, and this was associated with a trend to increased phosphorylation of the insulin-sensitive regulatory transcription factor FOXO3a. These data show that gene expression is highly altered and related to mitochondrial dysfunction and abnormal morphology in skeletal muscle from severely insulin resistant patients with T2D, and that this is associated with decreased expression of autophagy-related genes and proteins. We speculate that prolonged treatment with high doses of insulin may suppress autophagy thereby generating a vicious cycle maintaining insulin resistance.
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Affiliation(s)
- Andreas Buch Møller
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University, Denmark
| | - Ulla Kampmann
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Denmark
| | - Jakob Hedegaard
- Department of Molecular Medicine, Aarhus University Hospital, Denmark
| | - Kasper Thorsen
- Department of Molecular Medicine, Aarhus University Hospital, Denmark
| | - Iver Nordentoft
- Department of Molecular Medicine, Aarhus University Hospital, Denmark
| | - Mikkel Holm Vendelbo
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Denmark
| | - Niels Møller
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Denmark.,Medical Research Laboratory, Department of Clinical Medicine, Aarhus University Hospital, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University, Denmark.,Department of Molecular Medicine, Aarhus University Hospital, Denmark.,Department of Clinical Pharmacology, Aarhus University Hospital, Denmark
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Regulation of Carbohydrate Metabolism, Lipid Metabolism, and Protein Metabolism by AMPK. EXPERIENTIA SUPPLEMENTUM (2012) 2016; 107:23-43. [PMID: 27812975 DOI: 10.1007/978-3-319-43589-3_2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This chapter summarizes AMPK function in the regulation of substrate and energy metabolism with the main emphasis on carbohydrate and lipid metabolism, protein turnover, mitochondrial biogenesis, and whole-body energy homeostasis. AMPK acts as whole-body energy sensor and integrates different signaling pathway to meet both cellular and body energy requirements while inhibiting energy-consuming processes but also activating energy-producing ones. AMPK mainly promotes glucose and fatty acid catabolism, whereas it prevents protein, glycogen, and fatty acid synthesis.
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38
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Hardee JP, Mangum JE, Gao S, Sato S, Hetzler KL, Puppa MJ, Fix DK, Carson JA. Eccentric contraction-induced myofiber growth in tumor-bearing mice. J Appl Physiol (1985) 2015; 120:29-37. [PMID: 26494443 DOI: 10.1152/japplphysiol.00416.2015] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 10/16/2015] [Indexed: 02/07/2023] Open
Abstract
Cancer cachexia is characterized by the progressive loss of skeletal muscle mass. While mouse skeletal muscle's response to an acute bout of stimulated low-frequency concentric muscle contractions is disrupted by cachexia, gaps remain in our understanding of cachexia's effects on eccentric contraction-induced muscle growth. The purpose of this study was to determine whether repeated bouts of stimulated high-frequency eccentric muscle contractions [high-frequency electrical muscle stimulation (HFES)] could stimulate myofiber growth during cancer cachexia progression, and whether this training disrupted muscle signaling associated with wasting. Male Apc(Min/+) mice initiating cachexia (N = 9) performed seven bouts of HFES-induced eccentric contractions of the left tibialis anterior muscle over 2 wk. The right tibialis anterior served as the control, and mice were killed 48 h after the last stimulation. Age-matched C57BL/6 mice (N = 9) served as wild-type controls. Apc(Min/+) mice lost body weight, muscle mass, and type IIA, IIX, and IIB myofiber cross-sectional area. HFES increased myofiber cross-sectional area of all fiber types, regardless of cachexia. Cachexia increased muscle noncontractile tissue, which was attenuated by HFES. Cachexia decreased the percentage of high succinate dehydrogenase activity myofibers, which was increased by HFES, regardless of cachexia. While cachexia activated AMP kinase, STAT3, and ERK1/2 signaling, HFES decreased AMP kinase phosphorylation, independent of the suppression of STAT3. These results demonstrate that cachectic skeletal muscle can initiate a growth response to repeated eccentric muscle contractions, despite the presence of a systemic cachectic environment.
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Affiliation(s)
- Justin P Hardee
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and
| | - Joshua E Mangum
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and
| | - Song Gao
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and
| | - Shuichi Sato
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and
| | - Kimbell L Hetzler
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and
| | - Melissa J Puppa
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and
| | - Dennis K Fix
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and
| | - James A Carson
- Integrative Muscle Biology Laboratory, Department of Exercise Science, University of South Carolina, Columbia, South Carolina; and Center for Colon Cancer Research, University of South Carolina, Columbia, South Carolina
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Egawa T, Goto A, Ohno Y, Yokoyama S, Ikuta A, Suzuki M, Sugiura T, Ohira Y, Yoshioka T, Hayashi T, Goto K. Involvement of AMPK in regulating slow-twitch muscle atrophy during hindlimb unloading in mice. Am J Physiol Endocrinol Metab 2015; 309:E651-62. [PMID: 26244519 DOI: 10.1152/ajpendo.00165.2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 08/03/2015] [Indexed: 01/08/2023]
Abstract
AMPK is considered to have a role in regulating skeletal muscle mass. However, there are no studies investigating the function of AMPK in modulating skeletal muscle mass during atrophic conditions. In the present study, we investigated the difference in unloading-associated muscle atrophy and molecular functions in response to 2-wk hindlimb suspension between transgenic mice overexpressing the dominant-negative mutant of AMPK (AMPK-DN) and their wild-type (WT) littermates. Male WT (n = 24) and AMPK-DN (n = 24) mice were randomly divided into two groups: an untreated preexperimental control group (n = 12 in each group) and an unloading (n = 12 in each group) group. The relative soleus muscle weight and fiber cross-sectional area to body weight were decreased by ∼30% in WT mice by hindlimb unloading and by ∼20% in AMPK-DN mice. There were no changes in puromycin-labeled protein or Akt/70-kDa ribosomal S6 kinase signaling, the indicators of protein synthesis. The expressions of ubiquitinated proteins and muscle RING finger 1 mRNA and protein, markers of the ubiquitin-proteasome system, were increased by hindlimb unloading in WT mice but not in AMPK-DN mice. The expressions of molecules related to the protein degradation system, phosphorylated forkhead box class O3a, inhibitor of κBα, microRNA (miR)-1, and miR-23a, were decreased only in WT mice in response to hindlimb unloading, and 72-kDa heat shock protein expression was higher in AMPK-DN mice than in WT mice. These results imply that AMPK partially regulates unloading-induced atrophy of slow-twitch muscle possibly through modulation of the protein degradation system, especially the ubiquitin-proteasome system.
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Affiliation(s)
- Tatsuro Egawa
- Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan
| | - Ayumi Goto
- Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan; Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Yoshitaka Ohno
- Laboratory of Physiology, School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan
| | - Shingo Yokoyama
- Laboratory of Physiology, School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan
| | - Akihiro Ikuta
- Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan
| | - Miho Suzuki
- Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan
| | - Takao Sugiura
- Department of Exercise and Sports Physiology, Faculty of Education, Yamaguchi University, Yamaguchi, Japan
| | - Yoshinobu Ohira
- Graduate School of Health and Sports Science, Doshisha University, Kyotanabe, Kyoto, Japan; and
| | | | - Tatsuya Hayashi
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Katsumasa Goto
- Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan;
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40
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Madeddu C, Mantovani G, Gramignano G, Astara G, Macciò A. Muscle wasting as main evidence of energy impairment in cancer cachexia: future therapeutic approaches. Future Oncol 2015; 11:2697-2710. [PMID: 26376740 DOI: 10.2217/fon.15.195] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The present review aimed at discussing the impact, pathogenesis and therapeutic approaches of muscle wasting, which is a major clinical feature of cancer-related cachexia syndrome. The pathogenesis of muscle wasting in cancer cachexia lies in a discrepancy between anabolic and catabolic pathways mediated by chronic inflammation. Effective interventions specifically aimed at hampering muscle loss and enhancing muscle function are still lacking. Promising agents include anti-inflammatory, orexigenic and anabolic drugs, alongside with nutritional supplements that influence the STAT3 and PI3K/Akt/mTOR pathways involved in muscle wasting. Personalized physical activity combined with pharmacological and nutritional support hold promise. A greater understanding of the pathogenetic processes of cancer cachexia-related muscle wasting will enable the development of an early and effective targeted mechanism-based multimodal approach.
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Affiliation(s)
- Clelia Madeddu
- Department of Medical Sciences M Aresu, AOU Cagliari, University of Cagliari, Italy
| | - Giovanni Mantovani
- Department of Medical Sciences M Aresu, AOU Cagliari, University of Cagliari, Italy
| | | | - Giorgio Astara
- Department of Medical Sciences M Aresu, AOU Cagliari, University of Cagliari, Italy
| | - Antonio Macciò
- Department of Gynecologic Oncology, A Businco Hospital, Regional Referral Center for Cancer Diseases, Cagliari, Italy
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41
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Lee K, Ochi E, Song H, Nakazato K. Activation of AMP-activated protein kinase induce expression of FoxO1, FoxO3a, and myostatin after exercise-induced muscle damage. Biochem Biophys Res Commun 2015; 466:289-94. [PMID: 26342801 DOI: 10.1016/j.bbrc.2015.08.126] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 08/31/2015] [Indexed: 10/23/2022]
Abstract
AMP-activated protein kinase (AMPK) has been shown to regulate protein metabolism in skeletal muscle. We previously found that levels of Forkhead box proteins, FoxO1 and FoxO3a, and myostatin in rat gastrocnemius increased after exercise-induced muscle damage (EIMD). Eccentric muscle contractions (ECs), defined as elongation of muscle under tension, were used for inducing EIMD. The objective of this study was to clarify whether AMPK participates in activation and expression of FoxO proteins and myostatin in rat gastrocnemius muscle after EIMD. Wistar rats were randomly assigned into the following three groups; CON (n = 6), 180ECs group (ankle angular velocity, 180°/s; n = 6), and 30ECs group (ankle angular velocity, 30°/s; n = 6). 20 ECs were conducted with percutaneous electrical stimulation of gastrocnemius and simultaneous forced dorsiflexion of ankle joint (from 0° to 45°). To evaluate activation of AMPK, we measured the phosphorylated states of AMPK and acetyl CoA carboxylase. For evaluation of the direct relationships of AMPK and other proteins, we also examined contents of FoxOs and myostatin with stimulation of L6 myotube with AMPK agonist, 5 -aminoimidazole -4 -carboxamide -1-β-d-ribofuranoside (AICAR) (0.1, 0.5, 1, 1.5, and 2 mM). Western blotting was employed for protein analysis. Significant torque deficit was only observed in the 180ECs, suggesting EIMD. We also observed that phosphorylated AMPKα was induced in response to 180ECs (p < 0.01 vs. CON). Additionally, the level of phosphorylated acetyl CoA carboxylase was significantly higher in response to 180ECs and 30ECs. The phosphorylated states of FoxO1, FoxO3a, and myostatin expression were increased significantly in response to 180ECs. Furthermore, treatment of L6 myotubes with AICAR showed similar tendencies to that observed in in vivo gastrocnemius muscle treated with 180ECs. Therefore, we conclude that activation of AMPK plays a key role in increasing the level of FoxO1, FoxO3a, and myostatin in gastrocnemius after EIMD.
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Affiliation(s)
- Kihyuk Lee
- Graduate School of Health and Sport Sciences, Nippon Sport Science University, 7-1-1, Fukasawa, Setagaya, Tokyo 158-8508, Japan; Korea Institute of Sports Science, San223-19, Gongneung-dong Nowon-gu Seoul 139-242, South Korea.
| | - Eisuke Ochi
- Graduate School of Education, Okayama University, 3-1-1, Tsushimanaka, Kita, 700-8530, Okayama, Japan.
| | - Hongsun Song
- Korea Institute of Sports Science, San223-19, Gongneung-dong Nowon-gu Seoul 139-242, South Korea.
| | - Koichi Nakazato
- Graduate School of Health and Sport Sciences, Nippon Sport Science University, 7-1-1, Fukasawa, Setagaya, Tokyo 158-8508, Japan.
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Insulin down-regulates the expression of ubiquitin E3 ligases partially by inhibiting the activity and expression of AMP-activated protein kinase in L6 myotubes. Biosci Rep 2015; 35:BSR20150017. [PMID: 26193886 PMCID: PMC4613693 DOI: 10.1042/bsr20150017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 07/13/2015] [Indexed: 02/06/2023] Open
Abstract
We conclude that insulin inhibits AMPK through Akt phosphorylation in L6 myotubes, which may serve as a possible signalling pathway for the down-regulation of protein degradation. Besides, decreased expression of AMPK α2 may partially participate in inhibiting the activity of AMPK. While insulin is an anabolic hormone, AMP-activated protein kinase (AMPK) is not only a key energy regulator, but it can also control substrate metabolism directly by inducing skeletal muscle protein degradation. The hypothesis of the present study was that insulin inhibits AMPK and thus down-regulates the expression of the ubiquitin E3 ligases, muscle atrophy F-box (MAFbx) and muscle RING finger 1 (MuRF1) in skeletal muscle cells. Differentiated L6 myotubes were treated with 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR) and/or compound C to stimulate and/or block AMPK respectively. These treatments were also conducted in the presence or absence of insulin and the cells were analysed by western blot and quantitative real-time PCR. In addition, nuleotide levels were determined using HPLC. The activation of AMPK with AICAR enhanced the mRNA levels of MAFbx and MuRF1. Insulin reduced the phosphorylation and activity AMPK, which was accompanied by reduced MAFbx and MuRF1 mRNA levels. Using a protein kinase B (PKB/Akt) inhibitor, we found that insulin regulates AMPK through the activation of Akt. Furthermore, insulin down-regulated AMPK α2 mRNA. We conclude that insulin inhibits AMPK through Akt phosphorylation in L6 myotubes, which may serve as a possible signalling pathway for the down-regulation of protein degradation. In addition, decreased expression of AMPK α2 may partially participate in inhibiting the activity of AMPK.
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43
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Bakker AD, Jaspers RT. IL-6 and IGF-1 Signaling Within and Between Muscle and Bone: How Important is the mTOR Pathway for Bone Metabolism? Curr Osteoporos Rep 2015; 13:131-9. [PMID: 25712618 PMCID: PMC4417129 DOI: 10.1007/s11914-015-0264-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Insulin-like growth factor 1 (IGF-1) and interleukin 6 (IL-6) play an important role in the adaptation of both muscle and bone to mechanical stimuli. Here, we provide an overview of the functions of IL-6 and IGF-1 in bone and muscle metabolism, and the intracellular signaling pathways that are well known to mediate these functions. In particular, we discuss the Akt/mammalian target of rapamycin (mTOR) pathway which in skeletal muscle is known for its key role in regulating the rate of mRNA translation (protein synthesis). Since the role of the mTOR pathway in bone is explored to a much lesser extent, we discuss what is known about this pathway in bone and the potential role of this pathway in bone remodeling. We will also discuss the possible ways of influencing IGF-1 or IL-6 signaling by osteocytes and the clinical implications of pharmacological or nutritional modulation of the Akt/mTOR pathway.
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Affiliation(s)
- Astrid D. Bakker
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands
| | - Richard T. Jaspers
- Laboratory for Myology, MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands
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44
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Apró W, Moberg M, Hamilton DL, Ekblom B, van Hall G, Holmberg HC, Blomstrand E. Resistance exercise-induced S6K1 kinase activity is not inhibited in human skeletal muscle despite prior activation of AMPK by high-intensity interval cycling. Am J Physiol Endocrinol Metab 2015; 308:E470-81. [PMID: 25605643 DOI: 10.1152/ajpendo.00486.2014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Combining endurance and strength training in the same session has been reported to reduce the anabolic response to the latter form of exercise. The underlying mechanism, based primarily on results from rodent muscle, is proposed to involve AMPK-dependent inhibition of mTORC1 signaling. This hypothesis was tested in eight trained male subjects who in randomized order performed either resistance exercise only (R) or interval cycling followed by resistance exercise (ER). Biopsies taken from the vastus lateralis before and after endurance exercise and repeatedly after resistance exercise were assessed for glycogen content, kinase activity, protein phosphorylation, and gene expression. Mixed muscle fractional synthetic rate was measured at rest and during 3 h of recovery using the stable isotope technique. In ER, AMPK activity was elevated immediately after both endurance and resistance exercise (∼90%, P < 0.05) but was unchanged in R. Thr(389) phosphorylation of S6K1 was increased severalfold immediately after exercise (P < 0.05) in both trials and increased further throughout recovery. After 90 and 180 min recovery, S6K1 activity was elevated (∼55 and ∼110%, respectively, P < 0.05) and eukaryotic elongation factor 2 phosphorylation was reduced (∼55%, P < 0.05) with no difference between trials. In contrast, markers for protein catabolism were differently influenced by the two modes of exercise; ER induced a significant increase in gene and protein expression of MuRF1 (P < 0.05), which was not observed following R exercise only. In conclusion, cycling-induced elevation in AMPK activity does not inhibit mTOR complex 1 signaling after subsequent resistance exercise but may instead interfere with the hypertrophic response by influencing key components in protein breakdown.
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Affiliation(s)
- William Apró
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden; Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden;
| | - Marcus Moberg
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - D Lee Hamilton
- Health and Exercise Sciences Research Group, University of Stirling, Stirling, United Kingdom
| | - Björn Ekblom
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Gerrit van Hall
- Department of Biomedical Sciences, Rigshospitalet, University of Copenhagen, Denmark
| | - Hans-Christer Holmberg
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden; and
| | - Eva Blomstrand
- Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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45
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Kinnunen S, Mänttäri S, Herzig KH, Nieminen P, Mustonen AM, Saarela S. Maintenance of skeletal muscle energy homeostasis during prolonged wintertime fasting in the raccoon dog (Nyctereutes procyonoides). J Comp Physiol B 2015; 185:435-45. [PMID: 25652584 DOI: 10.1007/s00360-015-0893-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 12/19/2014] [Accepted: 01/20/2015] [Indexed: 12/31/2022]
Abstract
The raccoon dog (Nyctereutes procyonoides) is a canid species with autumnal fattening and prolonged wintertime fasting. Nonpathological body weight cycling and the ability to tolerate food deficiency make this species a unique subject for studying physiological mechanisms in energy metabolism. AMP-activated protein kinase (AMPK) is a cellular energy sensor regulating energy homeostasis. During acute fasting, AMPK promotes fatty acid oxidation and enhances glucose uptake. We evaluated the effects of prolonged fasting on muscle energy metabolism in farm-bred raccoon dogs. Total and phosphorylated AMPK and acetyl-CoA carboxylase (ACC), glucose transporter 4 (GLUT 4), insulin receptor and protein kinase B (Akt) protein expressions of hind limb muscles were determined by Western blot after 10 weeks of fasting. Plasma insulin, leptin, ghrelin, glucose and free fatty acid levels were measured, and muscle myosin heavy chain (MHC) isoform composition analyzed. Fasting had no effects on AMPK phosphorylation, but total AMPK expression decreased in m. rectus femoris, m. tibialis anterior and m. extensor digitorum longus resulting in a higher phosphorylation ratio. Decreased total expression was also observed for ACC. Fasting did not influence GLUT 4, insulin receptor or Akt expression, but Akt phosphorylation was lower in m. flexor digitorum superficialis and m. extensor digitorum longus. Three MHC isoforms (I, IIa and IIx) were detected without differences in composition between the fasted and control animals. The studied muscles were resistant to prolonged fasting indicating that raccoon dogs have an effective molecular regulatory system for preserving skeletal muscle function during wintertime immobility and fasting.
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Affiliation(s)
- Sanni Kinnunen
- Department of Biology, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland,
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Cannavino J, Brocca L, Sandri M, Grassi B, Bottinelli R, Pellegrino MA. The role of alterations in mitochondrial dynamics and PGC-1α over-expression in fast muscle atrophy following hindlimb unloading. J Physiol 2015; 593:1981-95. [PMID: 25565653 DOI: 10.1113/jphysiol.2014.286740] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/01/2015] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS Skeletal muscle atrophy occurs as a result of disuse. Although several studies have established that a decrease in protein synthesis and increase in protein degradation lead to muscle atrophy, little is known about the triggers underlying such processes. A growing body of evidence challenges oxidative stress as a trigger of disuse atrophy; furthermore, it is also becoming evident that mitochondrial dysfunction may play a causative role in determining muscle atrophy. Mitochondrial fusion and fission have emerged as important processes that govern mitochondrial function and PGC-1α may regulate fusion/fission events. Although most studies on mice have focused on the anti-gravitary slow soleus muscle as it is preferentially affected by disuse atrophy, several fast muscles (including gastrocnemius) go through a significant loss of mass following unloading. Here we found that in fast muscles an early down-regulation of pro-fusion proteins, through concomitant AMP-activated protein kinase (AMPK) activation, can activate catabolic systems, and ultimately cause muscle mass loss in disuse. Elevated muscle PGC-1α completely preserves muscle mass by preventing the fall in pro-fusion protein expression, AMPK and catabolic system activation, suggesting that compounds inducing PGC-1α expression could be useful to treat and prevent muscle atrophy. ABSTRACT The mechanisms triggering disuse muscle atrophy remain of debate. It is becoming evident that mitochondrial dysfunction may regulate pathways controlling muscle mass. We have recently shown that mitochondrial dysfunction plays a major role in disuse atrophy of soleus, a slow, oxidative muscle. Here we tested the hypothesis that hindlimb unloading-induced atrophy could be due to mitochondrial dysfunction in fast muscles too, notwithstanding their much lower mitochondrial content. Gastrocnemius displayed atrophy following both 3 and 7 days of unloading. SOD1 and catalase up-regulation, no H2 O2 accumulation and no increase of protein carbonylation suggest the antioxidant defence system efficiently reacted to redox imbalance in the early phases of disuse. A defective mitochondrial fusion (Mfn1, Mfn2 and OPA1 down-regulation) occurred together with an impairment of OXPHOS capacity. Furthermore, at 3 days of unloading higher acetyl-CoA carboxylase (ACC) phosphorylation was found, suggesting AMP-activated protein kinase (AMPK) pathway activation. To test the role of mitochondrial alterations we used Tg-mice overexpressing PGC-1α because of the known effect of PGC-1α on stimulation of Mfn2 expression. PGC-α overexpression was sufficient to prevent (i) the decrease of pro-fusion proteins (Mfn1, Mfn2 and OPA1), (ii) activation of the AMPK pathway, (iii) the inducible expression of MuRF1 and atrogin1 and of authopagic factors, and (iv) any muscle mass loss in response to disuse. As the effects of increased PGC-1α activity were sustained throughout disuse, compounds inducing PGC-1α expression could be useful to treat and prevent muscle atrophy also in fast muscles.
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Affiliation(s)
- Jessica Cannavino
- Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy
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Leucine supplementation does not affect protein turnover and impairs the beneficial effects of endurance training on glucose homeostasis in healthy mice. Amino Acids 2015; 47:745-55. [DOI: 10.1007/s00726-014-1903-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 12/11/2014] [Indexed: 11/26/2022]
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48
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Interference between concurrent resistance and endurance exercise: molecular bases and the role of individual training variables. Sports Med 2014; 44:743-62. [PMID: 24728927 DOI: 10.1007/s40279-014-0162-1] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Concurrent training is defined as simultaneously incorporating both resistance and endurance exercise within a periodized training regime. Despite the potential additive benefits of combining these divergent exercise modes with regards to disease prevention and athletic performance, current evidence suggests that this approach may attenuate gains in muscle mass, strength, and power compared with undertaking resistance training alone. This has been variously described as the interference effect or concurrent training effect. In recent years, understanding of the molecular mechanisms mediating training adaptation in skeletal muscle has emerged and provided potential mechanistic insight into the concurrent training effect. Although it appears that various molecular signaling responses induced in skeletal muscle by endurance exercise can inhibit pathways regulating protein synthesis and stimulate protein breakdown, human studies to date have not observed such molecular 'interference' following acute concurrent exercise that might explain compromised muscle hypertrophy following concurrent training. However, given the multitude of potential concurrent training variables and the limitations of existing evidence, the potential roles of individual training variables in acute and chronic interference are not fully elucidated. The present review explores current evidence for the molecular basis of the specificity of training adaptation and the concurrent interference phenomenon. Additionally, insights provided by molecular and performance-based concurrent training studies regarding the role of individual training variables (i.e., within-session exercise order, between-mode recovery, endurance training volume, intensity, and modality) in the concurrent interference effect are discussed, along with the limitations of our current understanding of this complex paradigm.
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Yun H, Park S, Kim MJ, Yang WK, Im DU, Yang KR, Hong J, Choe W, Kang I, Kim SS, Ha J. AMP-activated protein kinase mediates the antioxidant effects of resveratrol through regulation of the transcription factor FoxO1. FEBS J 2014; 281:4421-38. [DOI: 10.1111/febs.12949] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 07/18/2014] [Accepted: 07/24/2014] [Indexed: 12/31/2022]
Affiliation(s)
- Hee Yun
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Seolhui Park
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Min-Jung Kim
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Woo Kyeom Yang
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Dong Uk Im
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Ki Ryeol Yang
- College of Pharmacy; Kyung Hee University; Seoul Korea
| | - Jongki Hong
- College of Pharmacy; Kyung Hee University; Seoul Korea
| | - Wonchae Choe
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Insug Kang
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Sung Soo Kim
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
| | - Joohun Ha
- Department of Biochemistry and Molecular Biology; Medical Research Center and Biomedical Science Institute; School of Medicine; Kyung Hee University; Seoul Korea
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Ronnebaum SM, Patterson C, Schisler JC. Minireview: hey U(PS): metabolic and proteolytic homeostasis linked via AMPK and the ubiquitin proteasome system. Mol Endocrinol 2014; 28:1602-15. [PMID: 25099013 DOI: 10.1210/me.2014-1180] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
One of the master regulators of both glucose and lipid cellular metabolism is 5'-AMP-activated protein kinase (AMPK). As a metabolic pivot that dynamically responds to shifts in nutrient availability and stress, AMPK dysregulation is implicated in the underlying molecular pathology of a variety of diseases, including cardiovascular diseases, diabetes, cancer, neurological diseases, and aging. Although the regulation of AMPK enzymatic activity by upstream kinases is an active area of research, less is known about regulation of AMPK protein stability and activity by components of the ubiquitin-proteasome system (UPS), the cellular machinery responsible for both the recognition and degradation of proteins. Furthermore, there is growing evidence that AMPK regulates overall proteasome activity and individual components of the UPS. This review serves to identify the current understanding of the interplay between AMPK and the UPS and to promote further exploration of the relationship between these regulators of energy use and amino acid availability within the cell.
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Affiliation(s)
- Sarah M Ronnebaum
- McAllister Heart Institute (S.M.R., J.C.S.) and Department of Pharmacology (J.C.S.), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599; and Presbyterian Hospital/Weill-Cornell Medical Center (C.P.), New York, New York 10065
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