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Stacpoole PW, McCall CE. The pyruvate dehydrogenase complex: Life's essential, vulnerable and druggable energy homeostat. Mitochondrion 2023; 70:59-102. [PMID: 36863425 DOI: 10.1016/j.mito.2023.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/30/2023] [Accepted: 02/13/2023] [Indexed: 03/04/2023]
Abstract
Found in all organisms, pyruvate dehydrogenase complexes (PDC) are the keystones of prokaryotic and eukaryotic energy metabolism. In eukaryotic organisms these multi-component megacomplexes provide a crucial mechanistic link between cytoplasmic glycolysis and the mitochondrial tricarboxylic acid (TCA) cycle. As a consequence, PDCs also influence the metabolism of branched chain amino acids, lipids and, ultimately, oxidative phosphorylation (OXPHOS). PDC activity is an essential determinant of the metabolic and bioenergetic flexibility of metazoan organisms in adapting to changes in development, nutrient availability and various stresses that challenge maintenance of homeostasis. This canonical role of the PDC has been extensively probed over the past decades by multidisciplinary investigations into its causal association with diverse physiological and pathological conditions, the latter making the PDC an increasingly viable therapeutic target. Here we review the biology of the remarkable PDC and its emerging importance in the pathobiology and treatment of diverse congenital and acquired disorders of metabolic integration.
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Affiliation(s)
- Peter W Stacpoole
- Department of Medicine (Division of Endocrinology, Metabolism and Diabetes), and Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL, United States.
| | - Charles E McCall
- Department of Internal Medicine and Translational Sciences, and Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
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2
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Hammarström D, Øfsteng SJ, Jacobsen NB, Flobergseter KB, Rønnestad BR, Ellefsen S. Ribosome accumulation during early phase resistance training in humans. Acta Physiol (Oxf) 2022; 235:e13806. [PMID: 35213791 PMCID: PMC9540306 DOI: 10.1111/apha.13806] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/04/2022] [Accepted: 02/21/2022] [Indexed: 12/16/2022]
Abstract
Aim To describe ribosome biogenesis during resistance training, its relation to training volume and muscle growth. Methods A training group (n = 11) performed 12 sessions (3‐4 sessions per week) of unilateral knee extension with constant and variable volume (6 and 3‐9 sets per session respectively) allocated to either leg. Ribosome abundance and biogenesis markers were assessed from vastus lateralis biopsies obtained at baseline, 48 hours after sessions 1, 4, 5, 8, 9 and 12, and after eight days of de‐training, and from a control group (n = 8). Muscle thickness was measured before and after the intervention. Results Training led to muscle growth (3.9% over baseline values, 95% CrI: [0.2, 7.5] vs. control) with concomitant increases in total RNA, ribosomal RNA, upstream binding factor (UBF) and ribosomal protein S6 with no differences between volume conditions. Total RNA increased rapidly in response to the first four sessions (8.6% [5.6, 11.7] per session), followed by a plateau and peak values after session 8 (49.5% [34.5, 66.5] above baseline). Total RNA abundance was associated with UBF protein levels (5.0% [0.2, 10.2] per unit UBF), and the rate of increase in total RNA levels predicted hypertrophy (0.3 mm [0.1, 0.4] per %‐point increase in total RNA per session). After de‐training, total RNA decreased (−19.3% [−29.0, −8.1]) without muscle mass changes indicating halted biosynthesis of ribosomes. Conclusion Ribosomes accumulate in the initial phase of resistance training with abundances sensitive to training cessation and associated with UBF protein levels. The average accumulation rate predicts muscle training‐induced hypertrophy.
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Affiliation(s)
- Daniel Hammarström
- Section for Health and Exercise Physiology Department of Public Health and Sport Sciences Inland Norway University of Applied Sciences Lillehammer Norway
- Swedish School of Sport and Health Sciences Stockholm Sweden
| | - Sjur J. Øfsteng
- Section for Health and Exercise Physiology Department of Public Health and Sport Sciences Inland Norway University of Applied Sciences Lillehammer Norway
| | - Nicolai B. Jacobsen
- Section for Health and Exercise Physiology Department of Public Health and Sport Sciences Inland Norway University of Applied Sciences Lillehammer Norway
| | - Krister B. Flobergseter
- Section for Health and Exercise Physiology Department of Public Health and Sport Sciences Inland Norway University of Applied Sciences Lillehammer Norway
| | - Bent R. Rønnestad
- Section for Health and Exercise Physiology Department of Public Health and Sport Sciences Inland Norway University of Applied Sciences Lillehammer Norway
| | - Stian Ellefsen
- Section for Health and Exercise Physiology Department of Public Health and Sport Sciences Inland Norway University of Applied Sciences Lillehammer Norway
- Innlandet Hospital Trust Lillehammer Norway
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McAdam JS, Lyons KD, Beck DT, Haun CT, Romero MA, Mumford PW, Roberson PA, Young KC, Lohse KR, Roberts MD, Sefton JM. Whey Protein Supplementation Effects on Body Composition, Performance, and Blood Biomarkers During Army Initial Entry Training. Front Nutr 2022; 9:807928. [PMID: 35330708 PMCID: PMC8940516 DOI: 10.3389/fnut.2022.807928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/25/2022] [Indexed: 11/26/2022] Open
Abstract
This study assesses if a lower dose of whey protein can provide similar benefits to those shown in previous work supplementing Army Initial Entry Training (IET) Soldiers with two servings of whey protein (WP) per day. Eighty-one soldiers consumed one WP or a calorie matched carbohydrate (CHO) serving/day during IET (WP: n = 39, height = 173 ± 8 cm, body mass = 76.8 ± 12.8 kg, age = 21 ± 3 years; CHO: n = 42, 175 ± 8 cm, 77.8 ± 15.3 kg, 23 ± 4 years). Physical performance (push-ups, sit-ups, and a two-mile run) was assessed during weeks two and eight. All other measures (dietary intake, body composition, blood biomarkers) at weeks one and nine. There was a significant group difference for fat mass (p = 0.044) as WP lost 2.1 ± 2.9 kg and had a moderate effect size (Cohen's d: −0.24), whereas the CHO group lost 0.9 ± 2.5 kg and had only a small effect size (d: −0.1). There was no significant group-by-time interaction on fat-free mass (p = 0.069). WP gained 1.2 ± 2.4 (d: 0.1) and CHO gained 0.1 ± 3 (d: 0) kg of FFM on average. There was a significant group by week 1-fat free mass interaction (p = 0.003) indicating individuals with higher initial fat-free mass benefitted more from WP. There were no group differences for push-up (p = 0.514), sit-up (p = 0.429) or run (p = 0.313) performance. For all biomarkers there was a significant effect of time as testosterone (p < 0.01), testosterone to cortisol ratio (p = 0.39), and IGF-1 (p < 0.01) increased across training and cortisol (p = 0.04) and IL-6 (p < 0.01) decreased. There were no differences in groups across IET for any of the biomarkers. We conclude one WP serving is beneficial for FM and for FFM in soldiers with high baseline FFM but may not significantly alter biomarker response or physical performance of IET soldiers who have high relative dietary protein intakes.
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Affiliation(s)
- Jeremy S. McAdam
- School of Kinesiology, Warrior Research Center, Auburn University, Auburn, AL, United States
- Healthspan, Resilience, and Performance Research, Florida Institute for Human and Machine Cognition, Pensacola, FL, United States
| | - Kaitlin D. Lyons
- School of Kinesiology, Warrior Research Center, Auburn University, Auburn, AL, United States
| | - Darren T. Beck
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine (Auburn Campus), Auburn, AL, United States
| | - Cody T. Haun
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Fitomics, LLC, Pelham, AL, United States
| | - Matthew A. Romero
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Petey W. Mumford
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Paul A. Roberson
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Kaelin C. Young
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine (Auburn Campus), Auburn, AL, United States
| | - Keith R. Lohse
- Neurorehabilitation Informatics Lab, Department of Health, Kinesiology, and Recreation, University of Utah, Salt Lake City, UT, United States
| | - Michael D. Roberts
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, AL, United States
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine (Auburn Campus), Auburn, AL, United States
| | - JoEllen M. Sefton
- School of Kinesiology, Warrior Research Center, Auburn University, Auburn, AL, United States
- *Correspondence: JoEllen M. Sefton
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Bianco C, Mohr I. Ribosome biogenesis restricts innate immune responses to virus infection and DNA. eLife 2019; 8:49551. [PMID: 31841110 PMCID: PMC6934380 DOI: 10.7554/elife.49551] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 12/16/2019] [Indexed: 01/05/2023] Open
Abstract
Ribosomes are universally important in biology and their production is dysregulated by developmental disorders, cancer, and virus infection. Although presumed required for protein synthesis, how ribosome biogenesis impacts virus reproduction and cell-intrinsic immune responses remains untested. Surprisingly, we find that restricting ribosome biogenesis stimulated human cytomegalovirus (HCMV) replication without suppressing translation. Interfering with ribosomal RNA (rRNA) accumulation triggered nucleolar stress and repressed expression of 1392 genes, including High Mobility Group Box 2 (HMGB2), a chromatin-associated protein that facilitates cytoplasmic double-stranded (ds) DNA-sensing by cGAS. Furthermore, it reduced cytoplasmic HMGB2 abundance and impaired induction of interferon beta (IFNB1) mRNA, which encodes a critical anti-proliferative, proinflammatory cytokine, in response to HCMV or dsDNA in uninfected cells. This establishes that rRNA accumulation regulates innate immune responses to dsDNA by controlling HMGB2 abundance. Moreover, it reveals that rRNA accumulation and/or nucleolar activity unexpectedly regulate dsDNA-sensing to restrict virus reproduction and regulate inflammation. (145 words)
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Affiliation(s)
- Christopher Bianco
- Department of Microbiology, NYU School of Medicine, New York, United States
| | - Ian Mohr
- Department of Microbiology, NYU School of Medicine, New York, United States.,Laura and Isaac Perlmutter Cancer Institute, NYU School of Medicine, New York, United States
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Timmons JA, Volmar C, Crossland H, Phillips BE, Sood S, Janczura KJ, Törmäkangas T, Kujala UM, Kraus WE, Atherton PJ, Wahlestedt C. Longevity-related molecular pathways are subject to midlife "switch" in humans. Aging Cell 2019; 18:e12970. [PMID: 31168962 PMCID: PMC6612641 DOI: 10.1111/acel.12970] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/30/2019] [Accepted: 05/03/2019] [Indexed: 12/12/2022] Open
Abstract
Emerging evidence indicates that molecular aging may follow nonlinear or discontinuous trajectories. Whether this occurs in human neuromuscular tissue, particularly for the noncoding transcriptome, and independent of metabolic and aerobic capacities, is unknown. Applying our novel RNA method to quantify tissue coding and long noncoding RNA (lncRNA), we identified ~800 transcripts tracking with age up to ~60 years in human muscle and brain. In silico analysis demonstrated that this temporary linear "signature" was regulated by drugs, which reduce mortality or extend life span in model organisms, including 24 inhibitors of the IGF-1/PI3K/mTOR pathway that mimicked, and 5 activators that opposed, the signature. We profiled Rapamycin in nondividing primary human myotubes (n = 32 HTA 2.0 arrays) and determined the transcript signature for reactive oxygen species in neurons, confirming that our age signature was largely regulated in the "pro-longevity" direction. Quantitative network modeling demonstrated that age-regulated ncRNA equaled the contribution of protein-coding RNA within structures, but tended to have a lower heritability, implying lncRNA may better reflect environmental influences. Genes ECSIT, UNC13, and SKAP2 contributed to a network that did not respond to Rapamycin, and was associated with "neuron apoptotic processes" in protein-protein interaction analysis (FDR = 2.4%). ECSIT links inflammation with the continued age-related downwards trajectory of mitochondrial complex I gene expression (FDR < 0.01%), implying that sustained inhibition of ECSIT may be maladaptive. The present observations link, for the first time, model organism longevity programs with the endogenous but temporary genome-wide responses to aging in humans, revealing a pattern that may ultimately underpin personalized rates of health span.
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Affiliation(s)
- James A. Timmons
- Division of Genetics and Molecular MedicineKing's College LondonLondonUK
- Scion HouseStirling University Innovation ParkStirlingUK
| | - Claude‐Henry Volmar
- Department of Psychiatry and Behavioral Sciences, Center for Therapeutic InnovationUniversity of Miami Miller School of MedicineMiamiFlorida
| | - Hannah Crossland
- Division of Genetics and Molecular MedicineKing's College LondonLondonUK
- School of Medicine, Royal Derby HospitalUniversity of NottinghamDerbyUK
| | | | - Sanjana Sood
- Division of Genetics and Molecular MedicineKing's College LondonLondonUK
| | - Karolina J. Janczura
- Department of Psychiatry and Behavioral Sciences, Center for Therapeutic InnovationUniversity of Miami Miller School of MedicineMiamiFlorida
| | - Timo Törmäkangas
- Faculty of Sport and Health SciencesUniversity of JyväskyläJyväskyläFinland
| | - Urho M. Kujala
- Faculty of Sport and Health SciencesUniversity of JyväskyläJyväskyläFinland
| | | | | | - Claes Wahlestedt
- Department of Psychiatry and Behavioral Sciences, Center for Therapeutic InnovationUniversity of Miami Miller School of MedicineMiamiFlorida
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von Walden F. Ribosome biogenesis in skeletal muscle: coordination of transcription and translation. J Appl Physiol (1985) 2019; 127:591-598. [PMID: 31219775 DOI: 10.1152/japplphysiol.00963.2018] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Skeletal muscle mass responds in a remarkable manner to alterations in loading and use. It has long been clear that skeletal muscle hypertrophy can be prevented by inhibiting RNA synthesis. Since 80% of the cell's total RNA has been estimated to be rRNA, this finding indicates that de novo production of rRNA via transcription of the corresponding genes is important for such hypertrophy to occur. Transcription of rDNA by RNA Pol I is the rate-limiting step in ribosome biogenesis, indicating in turn that this biogenesis strongly influences the hypertrophic response. The present minireview focuses on 1) a brief description of the key steps in ribosome biogenesis and the relationship of this process to skeletal muscle mass and 2) the coordination of ribosome biogenesis and protein synthesis for growth or atrophy, as exemplified by the intracellular AMPK and mTOR pathways.
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Affiliation(s)
- Ferdinand von Walden
- Division of Pediatric Neurology, Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden
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Figueiredo VC, McCarthy JJ. Regulation of Ribosome Biogenesis in Skeletal Muscle Hypertrophy. Physiology (Bethesda) 2019; 34:30-42. [PMID: 30540235 PMCID: PMC6383632 DOI: 10.1152/physiol.00034.2018] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/11/2018] [Accepted: 09/13/2018] [Indexed: 01/22/2023] Open
Abstract
The ribosome is the enzymatic macromolecular machine responsible for protein synthesis. The rates of protein synthesis are primarily dependent on translational efficiency and capacity. Ribosome biogenesis has emerged as an important regulator of skeletal muscle growth and maintenance by altering the translational capacity of the cell. Here, we provide evidence to support a central role for ribosome biogenesis in skeletal muscle growth during postnatal development and in response to resistance exercise training. Furthermore, we discuss the cellular signaling pathways regulating ribosome biogenesis, discuss how myonuclear accretion affects translational capacity, and explore future areas of investigation within the field.
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Affiliation(s)
- Vandré Casagrande Figueiredo
- The Center for Muscle Biology, College of Health Sciences, University of Kentucky , Lexington, Kentucky
- Department of Rehabilitation Sciences, College of Medicine, University of Kentucky , Lexington, Kentucky
| | - John J McCarthy
- The Center for Muscle Biology, College of Health Sciences, University of Kentucky , Lexington, Kentucky
- Department of Physiology, University of Kentucky , Lexington, Kentucky
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