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Mirzoev TM, Shenkman BS. Regulation of Protein Synthesis in Inactivated Skeletal Muscle: Signal Inputs, Protein Kinase Cascades, and Ribosome Biogenesis. BIOCHEMISTRY (MOSCOW) 2018; 83:1299-1317. [PMID: 30482143 DOI: 10.1134/s0006297918110020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Disuse atrophy of skeletal muscles is characterized by a significant decrease in the mass and size of muscle fibers. Disuse atrophy develops as a result of prolonged reduction in the muscle functional activity caused by bed rest, limb immobilization, and real or simulated microgravity. Disuse atrophy is associated with the downregulation of protein biosynthesis and simultaneous activation of protein degradation. This review is focused on the key molecular mechanisms regulating the rate of protein synthesis in mammalian skeletal muscles during functional unloading.
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Affiliation(s)
- T M Mirzoev
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, 123007, Russia.
| | - B S Shenkman
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, 123007, Russia
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Rullman E, Fernandez-Gonzalo R, Mekjavić IB, Gustafsson T, Eiken O. MEF2 as upstream regulator of the transcriptome signature in human skeletal muscle during unloading. Am J Physiol Regul Integr Comp Physiol 2018; 315:R799-R809. [PMID: 29995456 DOI: 10.1152/ajpregu.00452.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Our understanding of skeletal muscle structural and functional alterations during unloading has increased in recent decades, yet the molecular mechanisms underpinning these changes have only started to be unraveled. The purpose of the current investigation was to assess changes in skeletal muscle gene expression after 21 days of bed rest, with a particular focus on predicting upstream regulators of muscle disuse. Additionally, the association between differential microRNA expression and the transcriptome signature of bed rest were investigated. mRNAs from musculus vastus lateralis biopsies obtained from 12 men before and after the bed rest were analyzed using a microarray. There were 54 significantly upregulated probesets after bed rest, whereas 103 probesets were downregulated (false discovery rate 10%; fold-change cutoff ≥1.5). Among the upregulated genes, transcripts related to denervation-induced alterations in skeletal muscle were identified, e.g., acetylcholine receptor subunit delta and perinatal myosin. The most downregulated transcripts were functionally enriched for mitochondrial genes and genes involved in mitochondrial biogenesis, followed by a large number of contractile fiber components. Upstream regulator analysis identified a robust inhibition of the myocyte enhancer factor-2 (MEF2) family, in particular MEF2C, which was suggested to act upstream of several key downregulated genes, most notably peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α)/peroxisome proliferator-activated receptors (PPARs) and CRSP3. Only a few microRNAs were identified as playing a role in the overall transcriptome picture induced by sustained bed rest. Our results suggest that the MEF2 family is a key regulator underlying the transcriptional signature of bed rest and, hence, ultimately also skeletal muscle alterations induced by systemic unloading in humans.
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Affiliation(s)
- Eric Rullman
- Department of Laboratory Medicine, Clinical Physiology, Karolinska Institutet and Karolinska University Hospital , Stockholm , Sweden.,Department of Cardiology, Karolinska University Hospital , Stockholm , Sweden
| | - Rodrigo Fernandez-Gonzalo
- Department of Laboratory Medicine, Clinical Physiology, Karolinska Institutet and Karolinska University Hospital , Stockholm , Sweden
| | - Igor B Mekjavić
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute , Ljubljana , Slovenia
| | - Thomas Gustafsson
- Department of Laboratory Medicine, Clinical Physiology, Karolinska Institutet and Karolinska University Hospital , Stockholm , Sweden
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, KTH Royal Institute of Technology , Stockholm , Sweden
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Salah H, Li M, Cacciani N, Gastaldello S, Ogilvie H, Akkad H, Namuduri AV, Morbidoni V, Artemenko KA, Balogh G, Martinez-Redondo V, Jannig P, Hedström Y, Dworkin B, Bergquist J, Ruas J, Vigh L, Salviati L, Larsson L. The chaperone co-inducer BGP-15 alleviates ventilation-induced diaphragm dysfunction. Sci Transl Med 2017; 8:350ra103. [PMID: 27488897 DOI: 10.1126/scitranslmed.aaf7099] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/29/2016] [Indexed: 12/28/2022]
Abstract
Ventilation-induced diaphragm dysfunction (VIDD) is a marked decline in diaphragm function in response to mechanical ventilation, which has negative consequences for individual patients' quality of life and for the health care system, but specific treatment strategies are still lacking. We used an experimental intensive care unit (ICU) model, allowing time-resolved studies of diaphragm structure and function in response to long-term mechanical ventilation and the effects of a pharmacological intervention (the chaperone co-inducer BGP-15). The marked loss of diaphragm muscle fiber function in response to mechanical ventilation was caused by posttranslational modifications (PTMs) of myosin. In a rat model, 10 days of BGP-15 treatment greatly improved diaphragm muscle fiber function (by about 100%), although it did not reverse diaphragm atrophy. The treatment also provided protection from myosin PTMs associated with HSP72 induction and PARP-1 inhibition, resulting in improvement of mitochondrial function and content. Thus, BGP-15 may offer an intervention strategy for reducing VIDD in mechanically ventilated ICU patients.
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Affiliation(s)
- Heba Salah
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden. Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala 75124, Sweden
| | - Meishan Li
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Nicola Cacciani
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Stefano Gastaldello
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Hannah Ogilvie
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Hazem Akkad
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Arvind Venkat Namuduri
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Valeria Morbidoni
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova 35128, Italy
| | - Konstantin A Artemenko
- Analytical Chemistry, Department of Chemistry-Biomedical Centre and Science for Life Laboratory (SciLifeLab), Uppsala University, Uppsala 75124, Sweden
| | - Gabor Balogh
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | | | - Paulo Jannig
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Yvette Hedström
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Barry Dworkin
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden. Department of Neuroscience, Pennsylvania State University, Hershey, PA 17033, USA
| | - Jonas Bergquist
- Analytical Chemistry, Department of Chemistry-Biomedical Centre and Science for Life Laboratory (SciLifeLab), Uppsala University, Uppsala 75124, Sweden. Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT 84112, USA. Precision Medicine, Binzhou Medical University, Yantai City, Shandong 264003, China
| | - Jorge Ruas
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden
| | - Laszlo Vigh
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova 35128, Italy
| | - Lars Larsson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm SE-177 77, Sweden. Department of Biobehavioral Health, Pennsylvania State University, University Park, PA 16802, USA. Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm SE-177 77, Sweden.
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Baehr LM, West DWD, Marshall AG, Marcotte GR, Baar K, Bodine SC. Muscle-specific and age-related changes in protein synthesis and protein degradation in response to hindlimb unloading in rats. J Appl Physiol (1985) 2017; 122:1336-1350. [PMID: 28336537 DOI: 10.1152/japplphysiol.00703.2016] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 02/16/2017] [Accepted: 02/26/2017] [Indexed: 12/19/2022] Open
Abstract
Disuse is a potent inducer of muscle atrophy, but the molecular mechanisms driving this loss of muscle mass are highly debated. In particular, the extent to which disuse triggers decreases in protein synthesis or increases in protein degradation, and whether these changes are uniform across muscles or influenced by age, is unclear. We aimed to determine the impact of disuse on protein synthesis and protein degradation in lower limb muscles of varied function and fiber type in adult and old rats. Alterations in protein synthesis and degradation were measured in the soleus, medial gastrocnemius, and tibialis anterior (TA) muscles of adult and old rats subjected to hindlimb unloading (HU) for 3, 7, or 14 days. Loss of muscle mass was progressive during the unloading period, but highly variable (-9 to -38%) across muscle types and between ages. Protein synthesis decreased significantly in all muscles, except for the old TA. Atrophy-associated gene expression was only loosely associated with protein degradation as muscle RING finger-1, muscle atrophy F-box (MAFbx), and Forkhead box O1 expression significantly increased in all muscles, but an increase in proteasome activity was only observed in the adult soleus. MAFbx protein levels were significantly higher in the old muscles compared with adult muscles, despite the old having higher expression of microRNA-23a. These results indicate that adult and old muscles respond similarly to HU, and the greatest loss in muscle mass occurs in predominantly slow-twitch extensor muscles due to a concomitant decrease in protein synthesis and increase in protein degradation.NEW & NOTEWORTHY In this study, we showed that age did not intensify the atrophy response to unloading in rats, but rather that the degree of atrophy was highly variable across muscles, indicating that changes in protein synthesis and protein degradation occur in a muscle-specific manner. Our data emphasize the importance of studying muscles of varying fiber-type and physiological function at multiple time points to fully understand the molecular mechanisms responsible for disuse atrophy.
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Affiliation(s)
- Leslie M Baehr
- Veterans Affairs Northern California Health Care System, Mather, California.,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and
| | - Daniel W D West
- Veterans Affairs Northern California Health Care System, Mather, California.,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and
| | - Andrea G Marshall
- Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and
| | - George R Marcotte
- Veterans Affairs Northern California Health Care System, Mather, California
| | - Keith Baar
- Veterans Affairs Northern California Health Care System, Mather, California.,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and.,Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, California
| | - Sue C Bodine
- Veterans Affairs Northern California Health Care System, Mather, California; .,Department of Physiology and Membrane Biology, University of California Davis, Davis, California; and.,Department of Neurobiology, Physiology and Behavior, University of California Davis, Davis, California
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Galvan E, Arentson-Lantz E, Lamon S, Paddon-Jones D. Protecting Skeletal Muscle with Protein and Amino Acid during Periods of Disuse. Nutrients 2016; 8:E404. [PMID: 27376322 PMCID: PMC4963880 DOI: 10.3390/nu8070404] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 06/16/2016] [Accepted: 06/23/2016] [Indexed: 12/18/2022] Open
Abstract
Habitual sedentary behavior increases risk of chronic disease, hospitalization and poor quality of life. Short-term bed rest or disuse accelerates the loss of muscle mass, function, and glucose tolerance. Optimizing nutritional practices and protein intake may reduce the consequences of disuse by preserving metabolic homeostasis and muscle mass and function. Most modes of physical inactivity have the potential to negatively impact the health of older adults more than their younger counterparts. Mechanistically, mammalian target of rapamycin complex 1 (mTORC1) signaling and muscle protein synthesis are negatively affected by disuse. This contributes to reduced muscle quality and is accompanied by impaired glucose regulation. Simply encouraging increased protein and/or energy consumption is a well-intentioned, but often impractical strategy to protect muscle health. Emerging evidence suggests that leucine supplemented meals may partially and temporarily protect skeletal muscle during disuse by preserving anabolism and mitigating reductions in mass, function and metabolic homeostasis.
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Affiliation(s)
- Elfego Galvan
- Center for Rehabilitation and Physical Activity and Nutrition (CeRPAN), University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Emily Arentson-Lantz
- Center for Rehabilitation and Physical Activity and Nutrition (CeRPAN), University of Texas Medical Branch, Galveston, TX 77555, USA.
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Séverine Lamon
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong 3125, Australia.
| | - Douglas Paddon-Jones
- Center for Rehabilitation and Physical Activity and Nutrition (CeRPAN), University of Texas Medical Branch, Galveston, TX 77555, USA.
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX 77555, USA.
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Tesch PA, Lundberg TR, Fernandez-Gonzalo R. Unilateral lower limb suspension: From subject selection to “omic” responses. J Appl Physiol (1985) 2016; 120:1207-14. [DOI: 10.1152/japplphysiol.01052.2015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The unilateral lower limb suspension (ULLS) method was developed, introduced, and validated in the quest for a simple, effective, and highly reliable human analog to study the consequences of spaceflight on muscle size and function. Because withdrawal of weight bearing for no more than 2–3 days is sufficient to inflict disturbances in protein metabolism of postural muscles, it is imperative ULLS serves as a very powerful method to manifest skeletal muscle adaptations similar to those experienced in 0 g. Thus the rate of global muscle loss appears rather constant over the first 2 mo, amounting to about 2–3% per week. At the microscopic level, these changes are accompanied by a corresponding decrease in individual muscle fiber size. ULLS alters metabolism favoring more carbohydrate over fat substrate utilization. Altogether, these changes result in impaired work and endurance capacity of muscles being subjected to ULLS. Maximal voluntary force decreases out of proportion to the muscle loss, suggesting motor control is modified. Past reviews offer near exhaustive information on ULLS-induced responses with regard to the above changes. Hence, the current brief review describes more broadly the evolution of the ULLS model, from issues of subject recruitment and compliance control, to recent advances unraveling molecular mechanisms facilitating unloading-induced muscle wasting. Such knowledge is critical in designing future studies aimed at exploring and developing exercise countermeasures or other means to combat the debilitating effects on muscle experienced by astronauts during long-haul missions in Orbit.
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Affiliation(s)
- Per A. Tesch
- Department of Physiology & Pharmacology, Karolinska Institutet, Stockholm, Sweden; and
| | - Tommy R. Lundberg
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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