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Hesketh SJ. Advancing cancer cachexia diagnosis with -omics technology and exercise as molecular medicine. SPORTS MEDICINE AND HEALTH SCIENCE 2024; 6:1-15. [PMID: 38463663 PMCID: PMC10918365 DOI: 10.1016/j.smhs.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/15/2024] [Accepted: 01/20/2024] [Indexed: 03/12/2024] Open
Abstract
Muscle atrophy exacerbates disease outcomes and increases mortality, whereas the preservation of skeletal muscle mass and function play pivotal roles in ensuring long-term health and overall quality-of-life. Muscle atrophy represents a significant clinical challenge, involving the continued loss of muscle mass and strength, which frequently accompany the development of numerous types of cancer. Cancer cachexia is a highly prevalent multifactorial syndrome, and although cachexia is one of the main causes of cancer-related deaths, there are still no approved management strategies for the disease. The etiology of this condition is based on the upregulation of systemic inflammation factors and catabolic stimuli, resulting in the inhibition of protein synthesis and enhancement of protein degradation. Numerous necessary cellular processes are disrupted by cachectic pathology, which mediate intracellular signalling pathways resulting in the net loss of muscle and organelles. However, the exact underpinning molecular mechanisms of how these changes are orchestrated are incompletely understood. Much work is still required, but structured exercise has the capacity to counteract numerous detrimental effects linked to cancer cachexia. Primarily through the stimulation of muscle protein synthesis, enhancement of mitochondrial function, and the release of myokines. As a result, muscle mass and strength increase, leading to improved mobility, and quality-of-life. This review summarises existing knowledge of the complex molecular networks that regulate cancer cachexia and exercise, highlighting the molecular interplay between the two for potential therapeutic intervention. Finally, the utility of mass spectrometry-based proteomics is considered as a way of establishing early diagnostic biomarkers of cachectic patients.
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Wang Y, Wang J, Tao SY, Liang Z, Xie R, Liu NN, Deng R, Zhang Y, Deng D, Jiang G. Mitochondrial damage-associated molecular patterns: A new insight into metabolic inflammation in type 2 diabetes mellitus. Diabetes Metab Res Rev 2024; 40:e3733. [PMID: 37823338 DOI: 10.1002/dmrr.3733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/18/2023] [Accepted: 09/08/2023] [Indexed: 10/13/2023]
Abstract
The pathogenesis of diabetes is accompanied by increased levels of inflammatory factors, also known as "metabolic inflammation", which runs through the whole process of the occurrence and development of the disease. Mitochondria, as the key site of glucose and lipid metabolism, is often accompanied by mitochondrial function damage in type 2 diabetes mellitus (T2DM). Damaged mitochondria release pro-inflammatory factors through damage-related molecular patterns that activate inflammation pathways and reactions to oxidative stress, further aggravate metabolic disorders, and form a vicious circle. Currently, the pathogenesis of diabetes is still unclear, and clinical treatment focuses primarily on symptomatic intervention of the internal environment of disorders of glucose and lipid metabolism with limited clinical efficacy. The proinflammatory effect of mitochondrial damage-associated molecular pattern (mtDAMP) in T2DM provides a new research direction for exploring the pathogenesis and intervention targets of T2DM. Therefore, this review covers the most recent findings on the molecular mechanism and related signalling cascades of inflammation caused by mtDAMP in T2DM and discusses its pathogenic role of it in the pathological process of T2DM to search potential intervention targets.
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Affiliation(s)
- Yan Wang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Jingwu Wang
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Si-Yu Tao
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | | | - Rong Xie
- Xinjiang Medical University, Urumqi, China
| | - Nan-Nan Liu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Ruxue Deng
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yuelin Zhang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Deqiang Deng
- Department of Endocrinology, Urumqi Hospital of Traditional Chinese Medicine, Urumqi, China
| | - Guangjian Jiang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
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3
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McQuate A, Knecht S, Raible DW. Activity regulates a cell type-specific mitochondrial phenotype in zebrafish lateral line hair cells. eLife 2023; 12:e80468. [PMID: 36912880 PMCID: PMC10129330 DOI: 10.7554/elife.80468] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 03/10/2023] [Indexed: 03/14/2023] Open
Abstract
Hair cells of the inner ear are particularly sensitive to changes in mitochondria, the subcellular organelles necessary for energy production in all eukaryotic cells. There are over 30 mitochondrial deafness genes, and mitochondria are implicated in hair cell death following noise exposure, aminoglycoside antibiotic exposure, as well as in age-related hearing loss. However, little is known about the basic aspects of hair cell mitochondrial biology. Using hair cells from the zebrafish lateral line as a model and serial block-face scanning electron microscopy, we have quantifiably characterized a unique hair cell mitochondrial phenotype that includes (1) a high mitochondrial volume and (2) specific mitochondrial architecture: multiple small mitochondria apically, and a reticular mitochondrial network basally. This phenotype develops gradually over the lifetime of the hair cell. Disrupting this mitochondrial phenotype with a mutation in opa1 impacts mitochondrial health and function. While hair cell activity is not required for the high mitochondrial volume, it shapes the mitochondrial architecture, with mechanotransduction necessary for all patterning, and synaptic transmission necessary for the development of mitochondrial networks. These results demonstrate the high degree to which hair cells regulate their mitochondria for optimal physiology and provide new insights into mitochondrial deafness.
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Affiliation(s)
- Andrea McQuate
- Department of Biological Structure, University of WashingtonSeattleUnited States
- Department of Otolaryngology-HNS, University of WashingtonSeattleUnited States
| | - Sharmon Knecht
- Department of Biological Structure, University of WashingtonSeattleUnited States
| | - David W Raible
- Department of Biological Structure, University of WashingtonSeattleUnited States
- Department of Otolaryngology-HNS, University of WashingtonSeattleUnited States
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Glucose Uptake Is Increased by Estradiol Dipropionate in L6 Skeletal Muscle Cells. Pharmaceuticals (Basel) 2022; 16:ph16010025. [PMID: 36678522 PMCID: PMC9866800 DOI: 10.3390/ph16010025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/05/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
GLUT4 is an important glucose transporter, which is closely related to insulin resistance and type 2 diabetes. In this study, we investigated the mechanism of Estradiol Dipropionate (EDP) on uptake of glucose in L6 skeletal muscle cells. In our study, we confirmed that EDP promoted uptake of glucose in L6 skeletal muscle cells in both normal and insulin resistant models. Western blot indicated that EDP accelerated GLUT4 expression and significantly activated AMPK and PKC phosphorylation; the expression of GLUT4 was significantly inhibited by AMPK inhibitor compound C and PKC inhibitor Gö6983, but not by Wortmannin (Akt inhibitor). Meanwhile, EDP boosted GLUT4 expression, and also increased intracellular Ca2+ levels. In the presence of 2 mM, 0 mM extracellular Ca2+ and 0 mM extracellular Ca2+ + BAPTA-AM, the involvement of intracellular Ca2+ levels contribute to EDP-induced GLUT4 expression and fusion with plasma membrane. Therefore, this study investigated whether EDP promoted GLUT4 expression through AMPK and PKC signaling pathways, thereby enhancing GLUT4 uptake of glucose and fusion into plasma membrane in L6 skeletal muscle cells. In addition, both EDP induced GLUT4 translocation and uptake of glucose were Ca2+ dependent. These findings suggested that EDP may be potential drug for the treatment of type 2 diabetes.
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Tripp TR, Frankish BP, Lun V, Wiley JP, Shearer J, Murphy RM, MacInnis MJ. Time course and fibre type-dependent nature of calcium-handling protein responses to sprint interval exercise in human skeletal muscle. J Physiol 2022; 600:2897-2917. [PMID: 35556249 DOI: 10.1113/jp282739] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/22/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Sprint interval training (SIT) has been shown to cause fragmentation of the sarcoplasmic reticulum calcium-release channel, ryanodine receptor 1 (RyR1) 24 hours post-exercise, which may act as a signal for mitochondrial biogenesis. In this study, we examined the time course of RyR1 fragmentation in human whole muscle and pooled type I and type II skeletal muscle fibres following a single session of SIT. Full-length RyR1 protein content was significantly lower than pre-exercise by 6 h post-SIT in whole muscle, and fragmentation was detectable in type II but not type I fibres, though to a lesser extent than in whole muscle. The peak in PGC1A mRNA expression occurred earlier than RyR1 fragmentation. The increased temporal resolution and fibre type-specific responses for RyR1 fragmentation provide insights into its importance to mitochondrial biogenesis in humans. ABSTRACT Sprint interval training (SIT) causes fragmentation of the skeletal muscle sarcoplasmic reticulum Ca2+ release channel, ryanodine receptor 1 (RyR1), 24h post-exercise, potentially signaling mitochondrial biogenesis by increasing cytosolic [Ca2+ ]. Yet, the time course and skeletal muscle fibre type-specific patterns of RyR1 fragmentation following a session of SIT remain unknown. Ten participants (n = 4 females; n = 6 males) performed a session of SIT (6 × 30 s "all-out" with 4.5 min rest after each sprint) with vastus lateralis muscle biopsy samples collected before and 3, 6, and 24h after exercise. In whole muscle, full-length RyR1 protein content was significantly reduced 6 h (mean [SD]; -38 [38]%; p<0.05) and 24 h post-SIT (-30 [48]%; p<0.05) compared to pre-exercise. Examining each participant's largest response in pooled samples, full-length RyR1 protein content was reduced in type II (-26 [30]%; p<0.05) but not type I fibres (-11 [40]%; p>0.05). 3h post-SIT, there was also a decrease in SERCA1 in type II fibres (-23 [17]%; p<0.05) and SERCA2a in type I fibres (-19 [21]%; p<0.05), despite no time effect for either protein in whole muscle samples (p>0.05). PGC1A mRNA content was elevated 3h and 6h post-SIT (5.3- and 3.7-fold change from pre, respectively; p<0.05 for both), but peak PGC1A mRNA expression was not significantly correlated with peak RyR1 fragmentation (r2 = 0.10; p>0.05). In summary, altered Ca2+ -handling protein expression, which occurs primarily in type II muscle fibres, may influence signals for mitochondrial biogenesis as early as 3-6 h post-SIT in humans. Abstract figure legend Western blotting was performed on whole muscle and pooled type I and II muscle fibre preparations derived from human vastus lateralis muscle biopsy samples collected before and after a single session of sprint interval training (SIT). Full-length ryanodine receptor 1 (RyR1) protein content was reduced 6 and 24 h post-exercise in whole muscle samples compared to baseline, despite a heterogeneous time course among individuals. This RyR1 fragmentation proceeded and outlasted the increase in peroxisome proliferator-activated γ receptor coactivator 1α (PGC1A) mRNA expression. When examining the time point of each individual's peak response, RyR1 fragmentation was evident in type II, but not type I, muscle fibres. These findings suggest that, in humans, mitochondrial biogenesis could be influenced by RyR1 fragmentation 3-6 h post-SIT in a fibre type-dependent manner. Created with BioRender.com. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Thomas R Tripp
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Barnaby P Frankish
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, Melbourne, Australia
| | - Victor Lun
- University of Calgary Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - J Preston Wiley
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,University of Calgary Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Jane Shearer
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robyn M Murphy
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Australia
| | - Martin J MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
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Molinari C, Ruga S, Farghali M, Galla R, Bassiouny A, Uberti F. Preventing c2c12 muscular cells damage combining magnesium and potassium with vitamin D3 and curcumin. J Tradit Complement Med 2021; 11:532-544. [PMID: 34765517 PMCID: PMC8572722 DOI: 10.1016/j.jtcme.2021.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 11/28/2022] Open
Abstract
Background and aim Physical activity is defined as any bodily movement produced by skeletal muscles which causes energy consumption; moderate and constant physical activity is known to be beneficial and to slow the muscle loss process associated with aging. The aim of the present study was to test, in an in vitro exercise model, the biological effects of a new formulation composed of magnesium and potassium combined with vitamin D and curcumin created to support muscle activity and to prevent hypercontraction damage. Experimental procedure C2C12 cells were treated with vitamin D, buffered magnesium bisglycinate, curcumin, and potassium citrate. Cell viability, morpho-functional changes, calcium and magnesium movements, and the main kinases involved in glucose uptake were analyzed. The glycogen level and lactate were also evaluated. Results and conclusion Important results about a positive effect on mitochondrial activity, ATP production, oxygen consumption and in the physiological differentiation of C2C12 cells were obtained. Further experiments were performed under conditions that mimic the biological aspects of strenuous exercise. The combination of magnesium, vitamin D3, curcumin, and potassium citrate revealed beneficial effects on skeletal muscle cells under physiological conditions as well as while mimicking intense activity. In particular, in an in vitro model, they were able to control the hypercontraction, restoring ion fluxes, reducing inflammation signaling and supporting the main mechanism involved on aerobic activity. Our results have indicated for the first time that this new combination could be considered as a new nutraceutical formulation to improve physical performance and muscle recovery.
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Affiliation(s)
- Claudio Molinari
- Laboratory of Physiology, Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
| | - Sara Ruga
- Laboratory of Physiology, Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
| | - Mahitab Farghali
- Laboratory of Physiology, Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
| | - Rebecca Galla
- Laboratory of Physiology, Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
| | - Ahmad Bassiouny
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Francesca Uberti
- Laboratory of Physiology, Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
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7
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Koh JH, Kim YW, Seo DY, Sohn TS. Mitochondrial TFAM as a Signaling Regulator between Cellular Organelles: A Perspective on Metabolic Diseases. Diabetes Metab J 2021; 45:853-865. [PMID: 34847642 PMCID: PMC8640147 DOI: 10.4093/dmj.2021.0138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/24/2021] [Indexed: 12/15/2022] Open
Abstract
Tissues actively involved in energy metabolism are more likely to face metabolic challenges from bioenergetic substrates and are susceptible to mitochondrial dysfunction, leading to metabolic diseases. The mitochondria receive signals regarding the metabolic states in cells and transmit them to the nucleus or endoplasmic reticulum (ER) using calcium (Ca2+) for appropriate responses. Overflux of Ca2+ in the mitochondria or dysregulation of the signaling to the nucleus and ER could increase the incidence of metabolic diseases including insulin resistance and type 2 diabetes mellitus. Mitochondrial transcription factor A (Tfam) may regulate Ca2+ flux via changing the mitochondrial membrane potential and signals to other organelles such as the nucleus and ER. Since Tfam is involved in metabolic function in the mitochondria, here, we discuss the contribution of Tfam in coordinating mitochondria-ER activities for Ca2+ flux and describe the mechanisms by which Tfam affects mitochondrial Ca2+ flux in response to metabolic challenges.
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Affiliation(s)
- Jin-Ho Koh
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea
- Corresponding authors: Jin-Ho Koh https://orcid.org/0000-0003-4777-4399 Department of Physiology, Yeungnam University College of Medicine, 170 Hyeonchungro, Nam-gu, Daegu 42415, Korea E-mail:
| | - Yong-Woon Kim
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea
| | - Dae-Yun Seo
- Cardiovascular and Metabolic Disease Center, Smart Marine Therapeutic Center, Department of Physiology, College of Medicine, Inje University, Busan, Korea
| | - Tae-Seo Sohn
- Department of Internal Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Tae-Seo Shon https://orcid.org/0000-0002-5135-3290 Department of Internal Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 271 Cheonbo-ro, Uijeongbu 11765, Korea E-mail:
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8
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Antioxidant and Anti-Inflammatory Profiles of Spent Coffee Ground Extracts for the Treatment of Neurodegeneration. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6620913. [PMID: 34104310 PMCID: PMC8159652 DOI: 10.1155/2021/6620913] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 04/06/2021] [Accepted: 04/29/2021] [Indexed: 11/17/2022]
Abstract
Spent coffee grounds (SCGs), waste products of coffee beverage production, are rich in organic compounds such as phenols. Different studies have demonstrated phenol beneficial effects in counteracting neurodegenerative diseases. These diseases are associated with oxidative stress and neuroinflammation, which initiates the degeneration of neurons by overactivating microglia. Unfortunately, to date, there are no pharmacological therapies to treat these pathologies. The aim of this study was to evaluate the phenolic content of 4 different SCG extracts and their ability to counteract oxidative stress and neuroinflammation. Caffeine and 5-O-caffeoylquinic acid were the most abundant compounds in all extracts, followed by 3-O-caffeoylquinic acid and 3,5-O-dicaffeoylquinic acid. The four extracts demonstrated a different ability to counteract oxidative stress and neuroinflammation in vitro. In particular, the methanol extract was the most effective in protecting neuron-like SH-SY5Y cells against H2O2-induced oxidative stress by upregulating endogenous antioxidant enzymes such as thioredoxin reductase, heme oxygenase 1, NADPH quinone oxidoreductase, and glutathione reductase. The water extract was the most effective in counteracting lipopolysaccharide-induced neuroinflammation in microglial BV-2 cells by strongly reducing the expression of proinflammatory mediators through the modulation of the TLR4/NF-κB pathway. On these bases, SCG extracts could represent valuable nutraceutical sources for the treatment of neurodegeneration.
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Yokokawa T, Hashimoto T, Iwanaka N. Caffeine increases myoglobin expression via the cyclic AMP pathway in L6 myotubes. Physiol Rep 2021; 9:e14869. [PMID: 33991466 PMCID: PMC8123560 DOI: 10.14814/phy2.14869] [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: 11/12/2020] [Revised: 12/07/2020] [Accepted: 12/14/2020] [Indexed: 11/24/2022] Open
Abstract
Myoglobin is an important regulator of muscle and whole‐body metabolism and exercise capacity. Caffeine, an activator of the calcium and cyclic AMP (cAMP)/protein kinase A (PKA) pathway, enhances glucose uptake, fat oxidation, and mitochondrial biogenesis in skeletal muscle cells. However, no study has shown that caffeine increases the endogenous expression of myoglobin in muscle cells. Further, the molecular mechanism underlying the regulation of myoglobin expression remains unclear. Therefore, our aim was to investigate whether caffeine and activators of the calcium signaling and cAMP/PKA pathway increase the expression of myoglobin in L6 myotubes and whether the pathway mediates caffeine‐induced myoglobin expression. Caffeine increased myoglobin expression and activated the cAMP/PKA pathway in L6 muscle cells. Additionally, a cAMP analog significantly increased myoglobin expression, whereas a ryanodine receptor agonist showed no significant effect. Finally, PKA inhibition significantly suppressed caffeine‐induced myoglobin expression in L6 myotubes. These results suggest that caffeine increases myoglobin expression via the cAMP/PKA pathway in skeletal muscle cells.
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Affiliation(s)
- Takumi Yokokawa
- Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan.,Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan.,College of Gastronomy Management, Ritsumeikan University, Shiga, Japan
| | - Takeshi Hashimoto
- Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Nobumasa Iwanaka
- Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan.,Faculty of Health Science, Kyoto Koka Women's University, Kyoto, Japan
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Nzekoue FK, Angeloni S, Navarini L, Angeloni C, Freschi M, Hrelia S, Vitali LA, Sagratini G, Vittori S, Caprioli G. Coffee silverskin extracts: Quantification of 30 bioactive compounds by a new HPLC-MS/MS method and evaluation of their antioxidant and antibacterial activities. Food Res Int 2020; 133:109128. [PMID: 32466943 DOI: 10.1016/j.foodres.2020.109128] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 02/05/2020] [Accepted: 02/25/2020] [Indexed: 01/08/2023]
Abstract
The research of value-added applications for coffee silverskin (CSS) requires studies to investigate potential bioactive compounds and biological activities in CSS extracts. In this study, different ultrasound-assisted extraction (UAE) methods have been tested to extract bioactive compounds from CSS. The obtained extracts, were characterized using a new HPLC-MS/MS method to detect and quantify 30 bioactive compounds of 2 classes: alkaloids and polyphenols (including phenolic acids, flavonoids, and secoiridoids). CSS extracts obtained with ethanol/water (70:30) as extraction solvent showed the highest levels (p ≤ 0.05) of bioactive compounds (4.01 ± 0.34% w/w). High content of caffeine was observed with levels varying from 1.00% to 3.59% of dry weight of extract (dw). 18 phenolic compounds were detected in CSS extracts with caffeoylquinic acids (3-CQA, 5-CQA and 3,5-diCQA) as the most abundant polyphenols (3115.6 µg g to -5444.0 µg g-1). This study is also one of the first to characterize in-depth flavonoids in CSS revealing the levels of different flavonoids compounds such as rutin (1.63-8.70 µg g-1), quercetin (1.53-2.46 µg g-1), kaempferol (0.76-1.66 µg g-1) and quercitrin (0.15-0.51 µg g-1). Neuroprotective activity of silverskin extracts against H2O2-induced damage was evaluated for the first time suggesting for methanol and ethanol/water (70:30) extracts a potential role as protective agents against neurodegeneration due to their ability to counteract oxidative stress and maintain cell viability. Silverskin extracts were not inhibiting the growth of anyone of the bacterial species included in this study but data obtained by water extract might deserve a deeper future investigation on biofilm-related activities, such as quorum sensing or virulence factors' expression. From their composition and their evidenced biological activities, CSS extracts could represent valuable ingredients in nutraceutical formulations.
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Affiliation(s)
| | - Simone Angeloni
- School of Pharmacy, University of Camerino, Via Sant' Agostino 1, 62032 Camerino, Italy; International Hub for Coffee Research and Innovation, Belforte del Chienti, MC, Italy
| | | | - Cristina Angeloni
- School of Pharmacy, University of Camerino, Via Sant' Agostino 1, 62032 Camerino, Italy
| | - Michela Freschi
- Department for Life Quality Studies, Alma Mater Studiorum University of Bologna, Rimini 47921, Italy
| | - Silvana Hrelia
- Department for Life Quality Studies, Alma Mater Studiorum University of Bologna, Rimini 47921, Italy
| | - Luca A Vitali
- School of Pharmacy, University of Camerino, Via Sant' Agostino 1, 62032 Camerino, Italy
| | - Gianni Sagratini
- School of Pharmacy, University of Camerino, Via Sant' Agostino 1, 62032 Camerino, Italy
| | - Sauro Vittori
- School of Pharmacy, University of Camerino, Via Sant' Agostino 1, 62032 Camerino, Italy
| | - Giovanni Caprioli
- School of Pharmacy, University of Camerino, Via Sant' Agostino 1, 62032 Camerino, Italy.
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Brooks GA. Lactate as a fulcrum of metabolism. Redox Biol 2020; 35:101454. [PMID: 32113910 PMCID: PMC7284908 DOI: 10.1016/j.redox.2020.101454] [Citation(s) in RCA: 266] [Impact Index Per Article: 66.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 01/28/2020] [Accepted: 02/05/2020] [Indexed: 12/17/2022] Open
Abstract
Mistakenly thought to be the consequence of oxygen lack in contracting skeletal muscle we now know that the L-enantiomer of the lactate anion is formed under fully aerobic conditions and is utilized continuously in diverse cells, tissues, organs and at the whole-body level. By shuttling between producer (driver) and consumer (recipient) cells lactate fulfills at least three purposes: 1] a major energy source for mitochondrial respiration; 2] the major gluconeogenic precursor; and 3] a signaling molecule. Working by mass action, cell redox regulation, allosteric binding, and reprogramming of chromatin by lactylation of lysine residues on histones, lactate has major influences in energy substrate partitioning. The physiological range of tissue [lactate] is 0.5–20 mM and the cellular Lactate/Pyruvate ratio (L/P) can range from 10 to >500; these changes during exercise and other stress-strain responses dwarf other metabolic signals in magnitude and span. Hence, lactate dynamics have rapid and major short- and long-term effects on cell redox and other control systems. By inhibiting lipolysis in adipose via HCAR-1, and muscle mitochondrial fatty acid uptake via malonyl-CoA and CPT1, lactate controls energy substrate partitioning. Repeated lactate exposure from regular exercise results in major effects on the expression of regulatory enzymes of glycolysis and mitochondrial respiration. Lactate is the fulcrum of metabolic regulation in vivo.
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Affiliation(s)
- George A Brooks
- Exercise Physiology Laboratory, Department of Integrative Biology, University of California, Berkeley, CA, 94720-3140, USA.
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12
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Huang H, Zhao Y, Shang X, Ren H, Zhao Y, Liu X. CAIII expression in skeletal muscle is regulated by Ca2+–CaMKII–MEF2C signaling. Exp Cell Res 2019; 385:111672. [DOI: 10.1016/j.yexcr.2019.111672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 09/25/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022]
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13
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NURR1 activation in skeletal muscle controls systemic energy homeostasis. Proc Natl Acad Sci U S A 2019; 116:11299-11308. [PMID: 31110021 DOI: 10.1073/pnas.1902490116] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Skeletal muscle plays a central role in the control of metabolism and exercise tolerance. Analysis of muscle enhancers activated after exercise in mice revealed the orphan nuclear receptor NURR1/NR4A2 as a prominent component of exercise-responsive enhancers. We show that exercise enhances the expression of NURR1, and transgenic overexpression of NURR1 in skeletal muscle enhances physical performance in mice. NURR1 expression in skeletal muscle is also sufficient to prevent hyperglycemia and hepatic steatosis, by enhancing muscle glucose uptake and storage as glycogen. Furthermore, treatment of obese mice with putative NURR1 agonists increases energy expenditure, improves glucose tolerance, and confers a lean phenotype, mimicking the effects of exercise. These findings identify a key role for NURR1 in governance of skeletal muscle glucose metabolism, and reveal a transcriptional link between exercise and metabolism. Our findings also identify NURR1 agonists as possible exercise mimetics with the potential to ameliorate obesity and other metabolic abnormalities.
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Ivarsson N, Mattsson CM, Cheng AJ, Bruton JD, Ekblom B, Lanner JT, Westerblad H. SR Ca 2+ leak in skeletal muscle fibers acts as an intracellular signal to increase fatigue resistance. J Gen Physiol 2019; 151:567-577. [PMID: 30635368 PMCID: PMC6445590 DOI: 10.1085/jgp.201812152] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 11/16/2018] [Indexed: 01/14/2023] Open
Abstract
Skeletal muscle oxidative capacity and fatigue resistance can be improved with endurance training, but the mechanism is not fully understood. Ivarsson et al. find that the signaling pathway that increases fatigue resistance in muscle is triggered by a mild Ca2+ leak from the sarcoplasmic reticulum. Effective practices to improve skeletal muscle fatigue resistance are crucial for athletes as well as patients with dysfunctional muscles. To this end, it is important to identify the cellular signaling pathway that triggers mitochondrial biogenesis and thereby increases oxidative capacity and fatigue resistance in skeletal muscle fibers. Here, we test the hypothesis that the stress induced in skeletal muscle fibers by endurance exercise causes a reduction in the association of FK506-binding protein 12 (FKBP12) with ryanodine receptor 1 (RYR1). This will result in a mild Ca2+ leak from the sarcoplasmic reticulum (SR), which could trigger mitochondrial biogenesis and improved fatigue resistance. After giving mice access to an in-cage running wheel for three weeks, we observed decreased FKBP12 association to RYR1, increased baseline [Ca2+]i, and signaling associated with greater mitochondrial biogenesis in muscle, including PGC1α1. After six weeks of voluntary running, FKBP12 association is normalized, baseline [Ca2+]i returned to values below that of nonrunning controls, and signaling for increased mitochondrial biogenesis was no longer present. The adaptations toward improved endurance exercise performance that were observed with training could be mimicked by pharmacological agents that destabilize RYR1 and thereby induce a modest Ca2+ leak. We conclude that a mild RYR1 SR Ca2+ leak is a key trigger for the signaling pathway that increases muscle fatigue resistance.
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Affiliation(s)
- Niklas Ivarsson
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Stockholm, Sweden
| | - C Mikael Mattsson
- Åstrand Laboratory of Work Physiology, The Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Arthur J Cheng
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Stockholm, Sweden
| | - Joseph D Bruton
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Stockholm, Sweden
| | - Björn Ekblom
- Åstrand Laboratory of Work Physiology, The Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Stockholm, Sweden
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Stockholm, Sweden
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15
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In vitro experimental models for examining the skeletal muscle cell biology of exercise: the possibilities, challenges and future developments. Pflugers Arch 2018; 471:413-429. [PMID: 30291430 DOI: 10.1007/s00424-018-2210-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/18/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022]
Abstract
Exercise provides a cornerstone in the prevention and treatment of several chronic diseases. The use of in vivo exercise models alone cannot fully establish the skeletal muscle-specific mechanisms involved in such health-promoting effects. As such, models that replicate exercise-like effects in vitro provide useful tools to allow investigations that are not otherwise possible in vivo. In this review, we provide an overview of experimental models currently used to induce exercise-like effects in skeletal muscle in vitro. In particular, the appropriateness of electrical pulse stimulation and several pharmacological compounds to resemble exercise, as well as important technical considerations, are addressed. Each model covered herein provides a useful tool to investigate different aspects of exercise with a level of abstraction not possible in vivo. That said, none of these models are perfect under all circumstances, and the choice of model (and terminology) used should be informed by the specific research question whilst accounting for the several inherent limitations of each model. Further work is required to develop and optimise the current experimental models used, such as combination with complementary techniques during treatment, and thereby improve their overall utility and impact within muscle biology research.
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16
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Hafen PS, Preece CN, Sorensen JR, Hancock CR, Hyldahl RD. Repeated exposure to heat stress induces mitochondrial adaptation in human skeletal muscle. J Appl Physiol (1985) 2018; 125:1447-1455. [PMID: 30024339 DOI: 10.1152/japplphysiol.00383.2018] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The heat stress response is associated with several beneficial adaptations that promote cell health and survival. Specifically, in vitro and animal investigations suggest that repeated exposures to a mild heat stress (~40°C) elicit positive mitochondrial adaptations in skeletal muscle comparable to those observed with exercise. To assess whether such adaptations translate to human skeletal muscle, we produced local, deep tissue heating of the vastus lateralis via pulsed shortwave diathermy in 20 men and women ( n = 10 men; n = 10 women). Diathermy increased muscle temperature by 3.9°C within 30 min of application. Immediately following a single 2-h heating session, we observed increased phosphorylation of AMP-activated protein kinase and ERK1/2 but not of p38 MAPK or JNK. Following repeated heat exposures (2 h daily for 6 consecutive days), we observed a significant cellular heat stress response, as heat shock protein 70 and 90 increased 45% and 38%, respectively. In addition, peroxisome proliferator-activated receptor gamma, coactivator-1 alpha and mitochondrial electron transport protein complexes I and V expression were increased after heating. These increases were accompanied by augmentation of maximal coupled and uncoupled respiratory capacity, measured via high-resolution respirometry. Our data provide the first evidence that mitochondrial adaptation can be elicited in human skeletal muscle in response to repeated exposures to mild heat stress. NEW & NOTEWORTHY Heat stress has been shown to elicit mitochondrial adaptations in cell culture and animal research. We used pulsed shortwave diathermy to produce deep tissue heating and explore whether beneficial mitochondrial adaptations would translate to human skeletal muscle in vivo. We report, for the first time, positive mitochondrial adaptations in human skeletal muscle following recurrent heat stress. The results of this study have clinical implications for many conditions characterized by diminished skeletal muscle mitochondrial function.
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Affiliation(s)
- Paul S Hafen
- Department of Exercise Sciences, Brigham Young University , Provo, Utah
| | - Coray N Preece
- Department of Exercise Sciences, Brigham Young University , Provo, Utah
| | - Jacob R Sorensen
- Department of Exercise Sciences, Brigham Young University , Provo, Utah
| | - Chad R Hancock
- Department of Nutrition, Dietetics & Food Science, Brigham Young University , Provo, Utah
| | - Robert D Hyldahl
- Department of Exercise Sciences, Brigham Young University , Provo, Utah
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17
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The Science and Translation of Lactate Shuttle Theory. Cell Metab 2018; 27:757-785. [PMID: 29617642 DOI: 10.1016/j.cmet.2018.03.008] [Citation(s) in RCA: 601] [Impact Index Per Article: 100.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 02/06/2018] [Accepted: 03/16/2018] [Indexed: 02/07/2023]
Abstract
Once thought to be a waste product of anaerobic metabolism, lactate is now known to form continuously under aerobic conditions. Shuttling between producer and consumer cells fulfills at least three purposes for lactate: (1) a major energy source, (2) the major gluconeogenic precursor, and (3) a signaling molecule. "Lactate shuttle" (LS) concepts describe the roles of lactate in delivery of oxidative and gluconeogenic substrates as well as in cell signaling. In medicine, it has long been recognized that the elevation of blood lactate correlates with illness or injury severity. However, with lactate shuttle theory in mind, some clinicians are now appreciating lactatemia as a "strain" and not a "stress" biomarker. In fact, clinical studies are utilizing lactate to treat pro-inflammatory conditions and to deliver optimal fuel for working muscles in sports medicine. The above, as well as historic and recent studies of lactate metabolism and shuttling, are discussed in the following review.
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18
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Amoasii L, Olson EN, Bassel-Duby R. Control of Muscle Metabolism by the Mediator Complex. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029843. [PMID: 28432117 DOI: 10.1101/cshperspect.a029843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Exercise represents an energetic challenge to whole-body homeostasis. In skeletal muscle, exercise activates a variety of signaling pathways that culminate in the nucleus to regulate genes involved in metabolism and contractility; however, much remains to be learned about the transcriptional effectors of exercise. Mediator is a multiprotein complex that links signal-dependent transcription factors and other transcriptional regulators with the basal transcriptional machinery, thereby serving as a transcriptional "hub." In this article, we discuss recent studies highlighting the role of Mediator subunits in metabolic regulation and glucose metabolism, as well as exercise responsiveness. Elucidation of the roles of Mediator subunits in metabolic control has revealed new mechanisms and molecular targets for the modulation of metabolism and metabolic disorders.
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Affiliation(s)
- Leonela Amoasii
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Eric N Olson
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Rhonda Bassel-Duby
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
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19
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Schnuck JK, Gould LM, Parry HA, Johnson MA, Gannon NP, Sunderland KL, Vaughan RA. Metabolic effects of physiological levels of caffeine in myotubes. J Physiol Biochem 2017; 74:35-45. [PMID: 29198059 DOI: 10.1007/s13105-017-0601-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/23/2017] [Indexed: 12/11/2022]
Abstract
Caffeine has been shown to stimulate multiple major regulators of cell energetics including AMP-activated protein kinase (AMPK) and Ca2+/calmodulin-dependent protein kinase II (CaMKII). Additionally, caffeine induces peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and mitochondrial biogenesis. While caffeine enhances oxidative metabolism, experimental concentrations often exceed physiologically attainable concentrations through diet. This work measured the effects of low-level caffeine on cellular metabolism and gene expression in myotubes, as well as the dependence of caffeine's effects on the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPARβ/δ). C2C12 myotubes were treated with various doses of caffeine for up to 24 h. Gene and protein expression were measured via qRT-PCR and Western blot, respectively. Cellular metabolism was determined via oxygen consumption and extracellular acidification rate. Caffeine significantly induced regulators of mitochondrial biogenesis and oxidative metabolism. Mitochondrial staining was suppressed in PPARβ/δ-inhibited cells which was rescued by concurrent caffeine treatment. Caffeine-treated cells also displayed elevated peak oxidative metabolism which was partially abolished following PPARβ/δ inhibition. Similar to past observations, glucose uptake and GLUT4 content were elevated in caffeine-treated cells, however, glycolytic metabolism was unaltered following caffeine treatment. Physiological levels of caffeine appear to enhance cell metabolism through mechanisms partially dependent on PPARβ/δ.
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Affiliation(s)
- Jamie K Schnuck
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Lacey M Gould
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Hailey A Parry
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
- School of Kinesiology, Auburn University, Auburn, AL, 36849, USA
| | - Michele A Johnson
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Nicholas P Gannon
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Kyle L Sunderland
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Roger A Vaughan
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA.
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20
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Gamu D, Trinh A, Fajardo VA, Bombardier E, Tupling AR. Sarcolipin expression is not required for the mitochondrial enzymatic response to physical activity or diet. J Appl Physiol (1985) 2017; 122:1276-1283. [PMID: 28183820 DOI: 10.1152/japplphysiol.00833.2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 02/06/2017] [Accepted: 02/06/2017] [Indexed: 11/22/2022] Open
Abstract
In mice, transgenic manipulation of Ca2+-handling proteins is sufficient to alter the metabolic phenotype of muscle. We have previously shown that ablation of sarcolipin (SLN), a regulatory protein and uncoupler of sarco(endo)plasmic reticulum Ca2+-ATPases, leads to excessive diet-induced obesity and glucose intolerance in mice. However, it is unclear how loss of SLN per se affects muscle oxidative capacity and the ability of mitochondria to adapt to physiological stimuli, such as exercise training or calorie overload. To address this question, Sln-/- and wild-type (WT) littermates were given access to voluntary running wheels or underwent a treadmill training protocol for 8 wk. Furthermore, a separate group of mice were given a high-fat diet (42% kcal from fat for 8 wk) to determine whether the excessively obese phenotype of Sln-/- mice is associated with altered oxidative capacity. While voluntary running was insufficient to elicit mitochondrial adaptations, treadmill-trained mice showed significant increases (P < 0.05) in the maximal activities of succinate dehydrogenase (+11%), citrate synthase (+12%), cytochrome oxidase (COX: +17%), along with increased protein expression of cytochrome c (+34%) and COX IV (+28%), which were irrespective of SLN expression. Lastly, no changes in the activities of mitochondrial marker enzymes existed with high-fat feeding, regardless of genotype. Together, these findings indicate that SLN is not required for the regulation of oxidative capacity in response to physiological stress, namely exercise or caloric surfeit.NEW & NOTEWORTHY Sarcolipin (SLN) has gained considerable attention for its uncoupling role of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA). Because of SLN's ability to alter both cellular energy use and cytosolic [Ca2+], the potential exists for a regulatory role of mitochondrial biogenesis. Herein, we show skeletal muscle oxidative capacity to be unaltered in mice lacking SLN following exercise training or high-fat feeding. Our results contrast with published studies of SLN-overexpressing mice, possibly owing to supraphysiological uncoupling of SERCA.
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Affiliation(s)
- Daniel Gamu
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Anton Trinh
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Val A Fajardo
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Eric Bombardier
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
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21
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Vaughan RA, White AC, Beam JR, Gannon NP, Garcia-Smith R, Salgado RM, Bisoffi M, Trujillo KA, Conn CA, Mermier CM. Effect of novel dietary supplement on metabolism in vitro and in vivo. J Tradit Complement Med 2017; 7:1-8. [PMID: 28053881 PMCID: PMC5198798 DOI: 10.1016/j.jtcme.2015.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 03/16/2015] [Accepted: 03/25/2015] [Indexed: 12/24/2022] Open
Abstract
Obesity is an increasingly prevalent and preventable morbidity with multiple behavioral, surgical and pharmacological interventions currently available. Commercial dietary supplements are often advertised to stimulate metabolism and cause rapid weight and/or fat loss, although few well-controlled studies have demonstrated such effects. We describe a commercially available dietary supplement (purportedly containing caffeine, catechins, and other metabolic stimulators) on resting metabolic rate in humans, and on metabolism, mitochondrial content, and related gene expression in vitro. Human males ingested either a placebo or commercially available supplement (RF) in a randomized double-blind placebo-controlled cross-over fashion. Metabolic rate, respiratory exchange ratio, and blood pressure were measured hourly for 3 h post-ingestion. To investigate molecular effects, human rhabdomyosarcoma cells (RD) and mouse myocytes (C2C12) were treated with various doses of RF for various durations. RF enhanced energy expenditure and systolic blood pressure in human males without altering substrate utilization. In myocytes, RF enhanced metabolism, metabolic gene expression, and mitochondrial content suggesting RF may target common energetic pathways which control mitochondrial biogenesis. RF appears to increase metabolism immediately following ingestion, although it is unclear if RF provides benefits beyond those provided by caffeine alone. Additional research is needed to examine safety and efficacy for human weight loss.
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Affiliation(s)
- Roger A. Vaughan
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX 79409, USA
- Department of Health, Exercise and Sports Science, University of New Mexico, Albuquerque, NM 87131, USA
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Department of Individual, Family, and Community Education: Nutrition, University of New Mexico, Albuquerque, NM 87131, USA
| | - Ailish C. White
- Department of Health, Exercise and Sports Science, University of New Mexico, Albuquerque, NM 87131, USA
| | - Jason R. Beam
- Department of Health, Exercise and Sports Science, University of New Mexico, Albuquerque, NM 87131, USA
| | - Nicholas P. Gannon
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Randi Garcia-Smith
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Roy M. Salgado
- Department of Health, Exercise and Sports Science, University of New Mexico, Albuquerque, NM 87131, USA
| | - Marco Bisoffi
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- University of New Mexico Cancer Center, Albuquerque, NM 87131, USA
- Biological Sciences, Chapman University, Orange, CA 92866, USA
| | - Kristina A. Trujillo
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- University of New Mexico Cancer Center, Albuquerque, NM 87131, USA
| | - Carole A. Conn
- Department of Individual, Family, and Community Education: Nutrition, University of New Mexico, Albuquerque, NM 87131, USA
| | - Christine M. Mermier
- Department of Health, Exercise and Sports Science, University of New Mexico, Albuquerque, NM 87131, USA
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22
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Abstract
Aims There are reports that ataxia telangiectasia mutated (ATM) can activate the AMP-activated protein kinase (AMPK) and also Akt, two kinases that play integral parts in cardioprotection and metabolic function. We hypothesized that chloroquine and resveratrol, both known ATM activators, would also activate AMPK and Akt. Main methods Phosphorylation of AMPK and Akt was assessed after C2C12 myotubes were exposed to chloroquine or resveratrol. Additional experiments were done in cells expressing shRNA against ATM or in the presence of the ATM inhibitor KU55933. The effects of chloroquine on intracellular calcium were assessed with the fluorescent probe Calcium Green-1 AM. Key findings 0.5 mM chloroquine increased AMPK phosphorylation by nearly four-fold (P < 0.05), and 0.25 mM chloroquine roughly doubled Akt phosphorylation (P < 0.05). Chloroquine also increased autophosphorylation of ATM by ∼50% (P < 0.05). Resveratrol (0.15 mM) increased AMPK phosphorylation about three-fold (P < 0.05) but in contrast to chloroquine sharply decreased Akt phosphorylation. Chloroquine increased AMPK and Akt phosphorylation in myotubes expressing shRNA against ATM that reduced ATM protein levels by about 90%. Likewise, chloroquine-stimulated phosphorylation of AMPK and Akt and resveratrol-stimulated phosphorylation of AMPK were not altered by inhibition of ATM. Chloroquine decreased intracellular calcium by >50% concomitant with a decrease in glucose transport. Significance These ATM-independent effects of chloroquine on AMPK and Akt and the additional effect to decrease intracellular calcium are likely to partially underlie the positive metabolic effects of chloroquine that have been reported in the literature.
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23
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Friedrich O, Reid MB, Van den Berghe G, Vanhorebeek I, Hermans G, Rich MM, Larsson L. The Sick and the Weak: Neuropathies/Myopathies in the Critically Ill. Physiol Rev 2015; 95:1025-109. [PMID: 26133937 PMCID: PMC4491544 DOI: 10.1152/physrev.00028.2014] [Citation(s) in RCA: 216] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Critical illness polyneuropathies (CIP) and myopathies (CIM) are common complications of critical illness. Several weakness syndromes are summarized under the term intensive care unit-acquired weakness (ICUAW). We propose a classification of different ICUAW forms (CIM, CIP, sepsis-induced, steroid-denervation myopathy) and pathophysiological mechanisms from clinical and animal model data. Triggers include sepsis, mechanical ventilation, muscle unloading, steroid treatment, or denervation. Some ICUAW forms require stringent diagnostic features; CIM is marked by membrane hypoexcitability, severe atrophy, preferential myosin loss, ultrastructural alterations, and inadequate autophagy activation while myopathies in pure sepsis do not reproduce marked myosin loss. Reduced membrane excitability results from depolarization and ion channel dysfunction. Mitochondrial dysfunction contributes to energy-dependent processes. Ubiquitin proteasome and calpain activation trigger muscle proteolysis and atrophy while protein synthesis is impaired. Myosin loss is more pronounced than actin loss in CIM. Protein quality control is altered by inadequate autophagy. Ca(2+) dysregulation is present through altered Ca(2+) homeostasis. We highlight clinical hallmarks, trigger factors, and potential mechanisms from human studies and animal models that allow separation of risk factors that may trigger distinct mechanisms contributing to weakness. During critical illness, altered inflammatory (cytokines) and metabolic pathways deteriorate muscle function. ICUAW prevention/treatment is limited, e.g., tight glycemic control, delaying nutrition, and early mobilization. Future challenges include identification of primary/secondary events during the time course of critical illness, the interplay between membrane excitability, bioenergetic failure and differential proteolysis, and finding new therapeutic targets by help of tailored animal models.
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Affiliation(s)
- O Friedrich
- Institute of Medical Biotechnology, Department of Chemical and Biological Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; College of Health and Human Performance, University of Florida, Gainesville, Florida; Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; and Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
| | - M B Reid
- Institute of Medical Biotechnology, Department of Chemical and Biological Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; College of Health and Human Performance, University of Florida, Gainesville, Florida; Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; and Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
| | - G Van den Berghe
- Institute of Medical Biotechnology, Department of Chemical and Biological Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; College of Health and Human Performance, University of Florida, Gainesville, Florida; Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; and Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
| | - I Vanhorebeek
- Institute of Medical Biotechnology, Department of Chemical and Biological Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; College of Health and Human Performance, University of Florida, Gainesville, Florida; Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; and Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
| | - G Hermans
- Institute of Medical Biotechnology, Department of Chemical and Biological Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; College of Health and Human Performance, University of Florida, Gainesville, Florida; Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; and Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
| | - M M Rich
- Institute of Medical Biotechnology, Department of Chemical and Biological Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; College of Health and Human Performance, University of Florida, Gainesville, Florida; Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; and Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
| | - L Larsson
- Institute of Medical Biotechnology, Department of Chemical and Biological Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; College of Health and Human Performance, University of Florida, Gainesville, Florida; Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; and Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
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24
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Abstract
Maximizing metabolic stress at a given level of mechanical stress can improve the adaptive response to endurance training, decrease injury, and potentially improve performance. Calcium and metabolic stress, in the form of heat, decreases in the adenosine triphosphate/adenosine diphosphate ratio, glycogen depletion, caloric restriction, and oxidative stress, are the primary determinants of the adaptation to training. These stressors increase the activity and amount of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), a protein that can directly induce the primary adaptive responses to endurance exercise: mitochondrial biogenesis, angiogenesis, and increases in fat oxidation. The activity of PGC-1α is regulated by its charge (phosphorylation and acetylation), whereas its transcription is regulated by proteins that bind to myocyte enhancing factor 2, enhancer box, and cyclic adenosine monophosphate response element sites within the PGC-1α promoter. This brief review will describe what is known about the control of PGC-1α by these metabolic stressors. As the duration of calcium release and the amount of metabolic stress, and therefore the activation of PGC-1α, can be directly modulated by training and nutrition, a simple strategy can be generated to maximize the adaptive response to endurance training.
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25
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Gannon NP, Conn CA, Vaughan RA. Dietary stimulators of GLUT4 expression and translocation in skeletal muscle: a mini-review. Mol Nutr Food Res 2014; 59:48-64. [PMID: 25215442 DOI: 10.1002/mnfr.201400414] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/07/2014] [Accepted: 09/08/2014] [Indexed: 12/23/2022]
Abstract
Chronic insulin resistance can lead to type II diabetes mellitus, which is also directly influenced by an individual's genetics as well as their lifestyle. Under normal circumstances, insulin facilitates glucose uptake in skeletal muscle and adipose tissue by stimulating glucose transporter 4 (GLUT4) translocation and activity. GLUT4 activity is directly correlated with the ability to clear elevated blood glucose and insulin sensitivity. In diabetes, energy excess and prolonged hyperinsulinemia suppress muscle and adipose response to insulin, in part through reduced GLUT4 membrane levels. This work uniquely describes much of the experimental data demonstrating the effects of various dietary components on GLUT4 expression and translocation in skeletal muscle. These observations implicate several individual dietary chemicals as potential adjuvant therapies in the maintenance of diabetes and insulin resistance.
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Affiliation(s)
- Nicholas P Gannon
- Department of Biochemistry and Molecular Biology, University of New Mexico, Health Sciences Center, School of Medicine, Albuquerque, NM, USA
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26
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Dietary stimulators of the PGC-1 superfamily and mitochondrial biosynthesis in skeletal muscle. A mini-review. J Physiol Biochem 2013; 70:271-84. [DOI: 10.1007/s13105-013-0301-4] [Citation(s) in RCA: 260] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 11/21/2013] [Indexed: 11/26/2022]
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Holloszy JO. Regulation of mitochondrial biogenesis and GLUT4 expression by exercise. Compr Physiol 2013; 1:921-40. [PMID: 23737207 DOI: 10.1002/cphy.c100052] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Endurance exercise training can induce large increases mitochondria and the GLUT4 isoform of the glucose transporter in skeletal muscle. For a long time after the discovery in the 1960s that exercise results in an increase in muscle mitochondria, there was no progress in elucidation of the mechanisms involved. The reason for this lack of progress was that nothing was known regarding how expression of the genes-encoding mitochondrial proteins is coordinately regulated. This situation changed rapidly after discovery of transcription factors that control transcription of genes-encoding mitochondrial proteins and, most importantly, the discovery of peroxisome proliferator-gamma coactivator-1α (PGC-1α). This transcription coactivator binds to and activates transcription factors that regulate transcription of genes-encoding mitochondrial proteins. Thus, PGC-1α activates and coordinates mitochondrial biogenesis. It is now known that exercise rapidly activates and induces increased expression of PGC-1α. The exercise-generated signals that lead to PGC-1α activation and increased expression are the increases in cytosolic Ca(2+) and decreases in ATP and creatine phosphate (∼P). Ca(2+) mediates its effect by activating CAMKII, while the decrease in ∼P mediates its effect via activation of AMPK. Expression of the GLUT4 isoform of the glucose transporter is regulated in parallel with mitochondrial biogenesis via the same signaling pathways. This review describes what is known regarding the regulation of mitochondrial biogenesis and GLUT4 expression by exercise. A major component of this review deals with the physiological and metabolic consequences of the exercise-induced increase in mitochondria and GLUT4.
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Affiliation(s)
- John O Holloszy
- Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, Missouri, USA.
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Abstract
Glucose is an important fuel for contracting muscle, and normal glucose metabolism is vital for health. Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon muscle contraction. Here we discuss the current understanding of how exercise-induced muscle glucose uptake is regulated. We briefly discuss the role of glucose supply and metabolism and concentrate on GLUT4 translocation and the molecular signaling that sets this in motion during muscle contractions. Contraction-induced molecular signaling is complex and involves a variety of signaling molecules including AMPK, Ca(2+), and NOS in the proximal part of the signaling cascade as well as GTPases, Rab, and SNARE proteins and cytoskeletal components in the distal part. While acute regulation of muscle glucose uptake relies on GLUT4 translocation, glucose uptake also depends on muscle GLUT4 expression which is increased following exercise. AMPK and CaMKII are key signaling kinases that appear to regulate GLUT4 expression via the HDAC4/5-MEF2 axis and MEF2-GEF interactions resulting in nuclear export of HDAC4/5 in turn leading to histone hyperacetylation on the GLUT4 promoter and increased GLUT4 transcription. Exercise training is the most potent stimulus to increase skeletal muscle GLUT4 expression, an effect that may partly contribute to improved insulin action and glucose disposal and enhanced muscle glycogen storage following exercise training in health and disease.
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Affiliation(s)
- Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
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29
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Dam AD, Mitchell AS, Quadrilatero J. Induction of mitochondrial biogenesis protects against caspase-dependent and caspase-independent apoptosis in L6 myoblasts. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3426-3435. [PMID: 23643731 DOI: 10.1016/j.bbamcr.2013.04.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 04/08/2013] [Accepted: 04/26/2013] [Indexed: 02/07/2023]
Abstract
Apoptotic signaling plays an important role in skeletal muscle degradation, atrophy, and dysfunction. Mitochondria are central executers of apoptosis by directly participating in caspase-dependent and caspase-independent cell death signaling. Given the important apoptotic role of mitochondria, altering mitochondrial content could influence apoptosis. Therefore, we examined the direct effect of modest, but physiological increases in mitochondrial biogenesis and content on skeletal muscle apoptosis using a cell culture approach. Treatment of L6 myoblasts with SNAP or AICAR (5h/day for 5days) significantly increased PGC-1, AIF, cytochrome c, and MnSOD protein content as well as MitoTracker staining. Following induction of mitochondrial biogenesis, L6 myoblasts displayed decreased sensitivity to apoptotic cell death as well as reduced caspase-3 and caspase-9 activation following exposure to staurosporine (STS) and C2-ceramide. L6 myoblasts with higher mitochondrial content also exhibited reduced apoptosis and AIF release following exposure to hydrogen peroxide (H2O2). Analysis of several key apoptosis regulatory proteins (ARC, Bax, Bcl-2, XIAP), antioxidant proteins (catalase, MnSOD, CuZnSOD), and reactive oxygen species (ROS) measures (DCF and MitoSOX fluorescence) revealed that these mechanisms were not responsible for the observed cellular protection. However, myoblasts with higher mitochondrial content were less sensitive to Ca(2+)-induced mitochondrial permeability transition pore formation (mPTP) and mitochondrial membrane depolarization. Collectively, these data demonstrate that increased mitochondrial content at physiological levels provides protection against apoptotic cell death by decreasing caspase-dependent and caspase-independent signaling through influencing mitochondrial Ca(2+)-mediated apoptotic events. Therefore, increasing mitochondrial biogenesis/content may represent a potential therapeutic approach in skeletal muscle disorders displaying increased apoptosis.
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Affiliation(s)
- Aaron D Dam
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Andrew S Mitchell
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Joe Quadrilatero
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
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Nitric oxide in skeletal muscle: role on mitochondrial biogenesis and function. Int J Mol Sci 2012; 13:17160-84. [PMID: 23242154 PMCID: PMC3546744 DOI: 10.3390/ijms131217160] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 12/04/2012] [Accepted: 12/05/2012] [Indexed: 01/18/2023] Open
Abstract
Nitric oxide (NO) has been implicated in several cellular processes as a signaling molecule and also as a source of reactive nitrogen species (RNS). NO is produced by three isoenzymes called nitric oxide synthases (NOS), all present in skeletal muscle. While neuronal NOS (nNOS) and endothelial NOS (eNOS) are isoforms constitutively expressed, inducible NOS (iNOS) is mainly expressed during inflammatory responses. Recent studies have demonstrated that NO is also involved in the mitochondrial biogenesis pathway, having PGC-1α as the main signaling molecule. Increased NO synthesis has been demonstrated in the sarcolemma of skeletal muscle fiber and NO can also reversibly inhibit cytochrome c oxidase (Complex IV of the respiratory chain). Investigation on cultured skeletal myotubes treated with NO donors, NO precursors or NOS inhibitors have also showed a bimodal effect of NO that depends on the concentration used. The present review will discuss the new insights on NO roles on mitochondrial biogenesis and function in skeletal muscle. We will also focus on potential therapeutic strategies based on NO precursors or analogs to treat patients with myopathies and mitochondrial deficiency.
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31
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Piantadosi CA, Suliman HB. Redox regulation of mitochondrial biogenesis. Free Radic Biol Med 2012; 53:2043-53. [PMID: 23000245 PMCID: PMC3604744 DOI: 10.1016/j.freeradbiomed.2012.09.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 09/07/2012] [Accepted: 09/11/2012] [Indexed: 12/21/2022]
Abstract
The cell renews, adapts, or expands its mitochondrial population during episodes of cell damage or periods of intensified energy demand by the induction of mitochondrial biogenesis. This bigenomic program is modulated by redox-sensitive signals that respond to physiological nitric oxide (NO), carbon monoxide (CO), and mitochondrial reactive oxygen species production. This review summarizes our current ideas about the pathways involved in the activation of mitochondrial biogenesis by the physiological gases leading to changes in the redox milieu of the cell, with an emphasis on the responses to oxidative stress and inflammation. The cell's energy supply is protected from conditions that damage mitochondria by an inducible transcriptional program of mitochondrial biogenesis that operates in large part through redox signals involving the nitric oxide synthase and the heme oxygenase-1/CO systems. These redox events stimulate the coordinated activities of several multifunctional transcription factors and coactivators also involved in the elimination of defective mitochondria and the expression of counterinflammatory and antioxidant genes, such as IL10 and SOD2, as part of a unified damage-control network. The redox-regulated mechanisms of mitochondrial biogenesis schematically outlined in the graphical abstract link mitochondrial quality control to an enhanced capacity to support the cell's metabolic needs while improving its resistance to metabolic failure and avoidance of cell death during periods of oxidative stress.
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Affiliation(s)
- Claude A Piantadosi
- Department of Medicine, Duke University Medical Center and the Durham VA Medical Center, Durham, NC 27710, USA.
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Abstract
Mitochondria are membrane bound organelles present in almost all eukaryotic cells. Responsible for orchestrating cellular energy production, they are central to the maintenance of life and the gatekeepers of cell death. Thought to have originated from symbiotic ancestors, they carry a residual genome as mtDNA encoding 13 proteins essential for respiratory chain function. Mitochondria comprise an inner and outer membrane that separate and maintain the aqueous regions, the intermembrane space and the matrix. Mitochondria contribute to many processes central to cellular function and dysfunction including calcium signalling, cell growth and differentiation, cell cycle control and cell death. Mitochondrial shape and positioning in cells is crucial and is tightly regulated by processes of fission and fusion, biogenesis and autophagy, ensuring a relatively constant mitochondrial population. Mitochondrial dysfunction is implicated in metabolic and age related disorders, neurodegenerative diseases and ischemic injury in heart and brain.
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Affiliation(s)
- Laura D. Osellame
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
- UK Parkinson’s Disease Consortium, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - Thomas S. Blacker
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Michael R. Duchen
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
- UK Parkinson’s Disease Consortium, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
- Corresponding author. Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom. Tel.: +44 20 7679 3207.
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Ludlow AT, Lima LCJ, Wang J, Hanson ED, Guth LM, Spangenburg EE, Roth SM. Exercise alters mRNA expression of telomere-repeat binding factor 1 in skeletal muscle via p38 MAPK. J Appl Physiol (1985) 2012; 113:1737-46. [PMID: 23042912 DOI: 10.1152/japplphysiol.00200.2012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Telomeres protect chromosome ends and shorten with age in most tissues. Integral to the maintenance of telomeres is the protein complex shelterin. The gene expression regulation of shelterin proteins to physiological stressors is not understood in vivo. We have recently reported increased telomere-repeat binding factor 1 (TRF1) protein expression and longer telomere length in skeletal muscle of sedentary compared with chronically active mice. These provocative observations led us to examine the effects of acute physiological stress on shelterin expression in vivo in mice and to further define potential mechanisms associated with gene regulation of shelterin. Three groups of female C57Bl/6 mice were studied: one control group and two groups that underwent a 30-min treadmill running bout and were killed either immediately following or 1-h after the exercise. Following the exercise bout, mRNA expression of Trf1 was significantly reduced in the plantaris muscle, and this reduction was paralleled by significant increases in p38 MAPK phosphorylation. To determine if p38 mediated the decreases in Trf1 mRNA expression, C2C12 myotubes were treated with the calcium ionophore, A23187. In response to the A23187, Trf1 gene expression was significantly reduced, coupled with significant increases in p38 phosphorylation, similar to in vivo data. C2C12 myotubes pretreated with a p38 inhibitor (SB-202190) prevented the A23187-induced decrease in Trf1 mRNA expression, indicating a link between Trf1 gene expression and p38 MAPK activation. While it is too early to definitively report the effect of exercise on telomere biology in rodents or humans, these data provide important mechanistic insights into the paradoxical telomere shortening that occurs in skeletal muscle in response to chronic exercise in mice.
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Affiliation(s)
- Andrew T Ludlow
- Department of Kinesiology, School of Public Health, University of Maryland at College Park, College Park, Maryland 20742, USA
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34
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Ding S, Riddoch-Contreras J, Contrevas JR, Abramov AY, Qi Z, Duchen MR. Mild stress of caffeine increased mtDNA content in skeletal muscle cells: the interplay between Ca2+ transients and nitric oxide. J Muscle Res Cell Motil 2012; 33:327-37. [PMID: 22926241 DOI: 10.1007/s10974-012-9318-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Accepted: 08/10/2012] [Indexed: 10/28/2022]
Abstract
Caffeine increases mitochondrial biogenesis in myotubes by evoking Ca(2+) transients. Nitric oxide (NO) also induces mitochondrial biogenesis in skeletal muscle cells via upregulation of AMP-activated protein kinase (AMPK) activity and PGC-1α. However, the interplay and timing sequence between Ca(2+) transients and NO releases remain unclear. Herein, we tested the hypothesis that caffeine-evoked Ca(2+) transients triggered NO production to increase mtDNA in skeletal muscle cells. Ca(2+) transients were recorded with Fura-2 AM and confocal microscopy; mtDNA staining, mitochondrial membrane potential and NO level were determined using fluorescent probes PicoGreen, tetramethylrhodamine methyl ester (TMRM) and DAF-FM, respectively. In primary cultured myotubes, a subtle and moderate stress of caffeine increased mtDNA exclusively. Mitochondrial membrane potential and mtDNA were increased by 1 mM as well as 5 mM caffeine, whereas 10 mM caffeine did not change the fluorescence intensity of PicoGreen and TMRM. NO level in myocytes increased gradually following the first jump of Ca(2+) transients evoked by caffeine (5 mM) till the end of recording, when Fura-2 indicated that Ca(2+) transients recovered partly and even disappeared. Importantly, nitric oxide synthase (NOS) inhibitor (L-NAME) suppressed caffeine-induced mtDNA biogenesis, whereas NO donor (DETA-NO) increased mtDNA content. These data strongly suggest that caffeine-induced mtDNA biogenesis is dose-sensitive and dependent on a certain level of stress. Further, an increasing level of NO following Ca(2+) transients is required for caffeine-induced mtDNA biogenesis. Additionally, Ca(2+) transients, a usual and first response to caffeine, was either suppressed or attenuated by L-NAME, DETA-NO, AICAR and U0126, suggesting an inability to control [Ca(2+)](i) in these treated cells. There may be an important interplay between NO and Ca(2+) transients in intracellular signaling system involving NOS, AMPK and MEK.
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Affiliation(s)
- Shuzhe Ding
- The Key Laboratory of Adolescent Health Assessment and Exercise Intervention, Ministry of Education of China, East China Normal University, Shanghai 200241, China.
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35
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Ojuka EO, Goyaram V, Smith JAH. The role of CaMKII in regulating GLUT4 expression in skeletal muscle. Am J Physiol Endocrinol Metab 2012; 303:E322-31. [PMID: 22496345 DOI: 10.1152/ajpendo.00091.2012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Contractile activity during physical exercise induces an increase in GLUT4 expression in skeletal muscle, helping to improve glucose transport capacity and insulin sensitivity. An important mechanism by which exercise upregulates GLUT4 is through the activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) in response to elevated levels of cytosolic Ca(2+) during muscle contraction. This review discusses the mechanism by which Ca(2+) activates CaMKII, explains research techniques currently used to alter CaMK activity in cells, and highlights various exercise models and pharmacological agents that have been used to provide evidence that CaMKII plays an important role in regulating GLUT4 expression. With regard to transcriptional mechanisms, the key research studies that identified myocyte enhancer factor 2 (MEF2) and GLUT4 enhancer factor as the major transcription factors regulating glut4 gene expression, together with their binding domains, are underlined. Experimental evidence showing that CaMK activation induces hyperacetylation of histones in the vicinity of the MEF2 domain and increases MEF2 binding to its cis element to influence MEF2-dependent Glut4 gene expression are also given along with data suggesting that p300 might be involved in acetylating histones on the Glut4 gene. Finally, an appraisal of the roles of other calcium- and non-calcium-dependent mechanisms, including the major HDAC kinases in GLUT4 expression, is also given.
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Affiliation(s)
- Edward O Ojuka
- University of Capetown/Medical Research Center Research Unit for Exercise Science & Sports Medicine, Department of Human Biology, Univeristy of Cape Town, Cape Town, South Africa.
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36
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Barrès R, Yan J, Egan B, Treebak JT, Rasmussen M, Fritz T, Caidahl K, Krook A, O'Gorman DJ, Zierath JR. Acute exercise remodels promoter methylation in human skeletal muscle. Cell Metab 2012; 15:405-11. [PMID: 22405075 DOI: 10.1016/j.cmet.2012.01.001] [Citation(s) in RCA: 576] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 10/11/2011] [Accepted: 01/05/2012] [Indexed: 12/31/2022]
Abstract
DNA methylation is a covalent biochemical modification controlling chromatin structure and gene expression. Exercise elicits gene expression changes that trigger structural and metabolic adaptations in skeletal muscle. We determined whether DNA methylation plays a role in exercise-induced gene expression. Whole genome methylation was decreased in skeletal muscle biopsies obtained from healthy sedentary men and women after acute exercise. Exercise induced a dose-dependent expression of PGC-1α, PDK4, and PPAR-δ, together with a marked hypomethylation on each respective promoter. Similarly, promoter methylation of PGC-1α, PDK4, and PPAR-δ was markedly decreased in mouse soleus muscles 45 min after ex vivo contraction. In L6 myotubes, caffeine exposure induced gene hypomethylation in parallel with an increase in the respective mRNA content. Collectively, our results provide evidence that acute gene activation is associated with a dynamic change in DNA methylation in skeletal muscle and suggest that DNA hypomethylation is an early event in contraction-induced gene activation.
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Affiliation(s)
- Romain Barrès
- Department of Molecular Medicine and Surgery, Karolinska University Hospital, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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37
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Piantadosi CA, Suliman HB. Transcriptional control of mitochondrial biogenesis and its interface with inflammatory processes. Biochim Biophys Acta Gen Subj 2012; 1820:532-41. [PMID: 22265687 DOI: 10.1016/j.bbagen.2012.01.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 12/23/2011] [Accepted: 01/07/2012] [Indexed: 12/28/2022]
Abstract
BACKGROUND Cells avoid major mitochondrial damage and energy failure during systemic inflammatory states, such as severe acute infections, by specific targeting of the inflammatory response and by inducing anti-inflammatory and anti-oxidant defenses. Recent evidence indicates that these cell defenses also include mitochondrial biogenesis and the clearance of damaged mitochondria through autophagy. SCOPE OF REVIEW This review addresses a group of transcriptional signaling mechanisms that engage mitochondrial biogenesis, including energy-sensing and redox-regulated transcription factors and co-activators, after major inflammatory events. MAJOR CONCLUSIONS Stimulation of the innate immune system by activation of toll-like receptors (TLR) generates pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α)and interleukin-1β (IL-1β), necessary for optimal host defense, but which also contribute to mitochondrial damage through oxidative stress and other mechanisms. To protect its energy supply, host cells sense mitochondrial damage and initiate mitochondrial biogenesis under the control of an inducible transcriptional program that also activates anti-oxidant and anti-inflammatory gene expression. This multifunctional network not only increases cellular resistance to metabolic failure, oxidative stress, and cell death, but promotes immune tolerance as shown in the graphical abstract. GENERAL SIGNIFICANCE The post-inflammatory induction of mitochondrial biogenesis supports metabolic function and cell viability while helping to control inflammation. In clinical settings, patients recovering from severe systemic infections may develop transient immune suppression, placing them at risk for recurrent infection, but there may be therapeutic opportunities to enhance mitochondrial quality control that would improve the resolution of life-threatening host responses to such infections.
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Affiliation(s)
- Claude A Piantadosi
- Department of Medicine, Duke University Medical Center, and Durham VA Medical Center, Durham, NC 27710, USA.
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38
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Le Pennec S, Mirebeau-Prunier D, Boutet-Bouzamondo N, Jacques C, Guillotin D, Lauret E, Houlgatte R, Malthièry Y, Savagner F. Nitric oxide and calcium participate in the fine regulation of mitochondrial biogenesis in follicular thyroid carcinoma cells. J Biol Chem 2011; 286:18229-39. [PMID: 21454643 PMCID: PMC3093895 DOI: 10.1074/jbc.m110.217521] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 03/29/2011] [Indexed: 11/06/2022] Open
Abstract
Members of the peroxisome proliferator-activated receptor γ coactivator-1 family (i.e. PGC-1α, PGC-1β, and the PGC-1-related coactivator (PRC)) are key regulators of mitochondrial biogenesis and function. These regulators serve as mediators between environmental or endogenous signals and the transcriptional machinery governing mitochondrial biogenesis. The FTC-133 and RO82 W-1 follicular thyroid carcinoma cell lines, which present significantly different numbers of mitochondria, metabolic mechanisms, and expression levels of PRC and PGC-1α, may employ retrograde signaling in response to respiratory dysfunction. Nitric oxide (NO) and calcium have been hypothesized to participate in this activity. We investigated the effects of the S-nitroso-N-acetyl-DL-penicillamine-NO donor, on the expression of genes involved in mitochondrial biogenesis and cellular metabolic functions in FTC-133 and RO82 W-1 cells by measuring lactate dehydrogenase and cytochrome c oxidase (COX) activities. We studied the action of ionomycin and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM) (i.e. a calcium ionophore and a cytosolic calcium chelator) on whole genome expression and mitochondrial biogenesis in RO82 W-1 cells. COX activity and the dynamics of endoplasmic reticulum and mitochondrial networks were analyzed in regard to calcium-modulating treatments. In the FTC-133 and RO82 W-1 cells, the mitochondrial biogenesis induced by NO was mainly related to PRC expression as a retrograde mitochondrial signaling. Ionomycin diminished COX activity and negatively regulated PRC-mediated mitochondrial biogenesis in RO82 W-1 cells, whereas BAPTA/AM produced the opposite effects with a reorganization of the mitochondrial network. This is the first demonstration that NO and calcium regulate mitochondrial biogenesis through the PRC pathway in thyroid cell lines.
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Affiliation(s)
| | - Delphine Mirebeau-Prunier
- From INSERM UMR694
- Université d'Angers, and
- Laboratoire de Biochimie, Centre Hospitalier Universitaire d'Angers, F-49033 Angers, France
| | | | | | | | | | - Rémi Houlgatte
- INSERM UMR915, l'Institut du Thorax, F-44007 Nantes, France, and
- Université de Nantes, F-44035 Nantes, France
| | - Yves Malthièry
- From INSERM UMR694
- Université d'Angers, and
- Laboratoire de Biochimie, Centre Hospitalier Universitaire d'Angers, F-49033 Angers, France
| | - Frédérique Savagner
- From INSERM UMR694
- Université d'Angers, and
- Laboratoire de Biochimie, Centre Hospitalier Universitaire d'Angers, F-49033 Angers, France
- INSERM UMR915, l'Institut du Thorax, F-44007 Nantes, France, and
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39
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Wadley GD, McConell GK. High-dose antioxidant vitamin C supplementation does not prevent acute exercise-induced increases in markers of skeletal muscle mitochondrial biogenesis in rats. J Appl Physiol (1985) 2010; 108:1719-26. [PMID: 20395544 DOI: 10.1152/japplphysiol.00127.2010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
High doses of the antioxidant vitamin C prevent the increases in skeletal muscle mitochondrial biogenesis after exercise training. Since exercise training effects rely on the acute stimulus of each exercise bout, we examined whether vitamin C supplementation also attenuates the increases in skeletal muscle metabolic signaling and mitochondrial biogenesis in response to an acute exercise bout. Male Sprague-Dawley rats performed 60 min of treadmill running (27 m/min, 5% grade) or remained sedentary. For 7 days before this, one-half of the rats received water containing 500 mg/kg body wt vitamin C. Acute exercise significantly ( P < 0.05) increased the phosphorylation of p38 MAPK, AMP-activated kinase-α, and activating transcription factor (ATF)-2 and the ratio of oxidized to total glutathione (GSSG/TGSH) in the gastrocnemius. However, vitamin C had no effect on these increases. Similarly, vitamin C did not prevent the exercise-induced increases in peroxisome proliferator-activated receptor-γ coactivator-1α, nuclear respiratory factor (NRF)-1, NRF-2, mitochondrial transcription factor A, glutathione peroxidase-1, MnSOD, extracellular SOD, or glucose transporter 4 ( P < 0.05) mRNA after exercise. Surprisingly, vitamin C supplementation significantly increased the basal levels of GSSG/TGSH, NRF-1, and NRF-2 mRNA and basal ATF-2 phosphorylation. In summary, despite other studies in rats showing that vitamin C supplementation prevents increases in skeletal muscle mitochondrial biogenesis and antioxidant enzymes with exercise training, vitamin C had no affect on the acute exercise-induced increases of these markers.
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Affiliation(s)
- G. D. Wadley
- Department of Physiology, The University of Melbourne, Parkville, Victoria; and
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria
| | - G. K. McConell
- Department of Physiology, The University of Melbourne, Parkville, Victoria; and
- Institute of Sport, Exercise and Active Living and Biomedical and Health Sciences, Victoria University, Victoria, Australia
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40
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McConell GK, Ng GPY, Phillips M, Ruan Z, Macaulay SL, Wadley GD. Central role of nitric oxide synthase in AICAR and caffeine-induced mitochondrial biogenesis in L6 myocytes. J Appl Physiol (1985) 2009; 108:589-95. [PMID: 20044477 DOI: 10.1152/japplphysiol.00377.2009] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
5-Aminoimidazole-4-carboxamide-ribonucleoside (AICAR) and caffeine, which activate AMP-activated protein kinase (AMPK) and cause sarcoplasmic reticulum calcium release, respectively, have been shown to increase mitochondrial biogenesis in L6 myotubes. Nitric oxide (NO) donors also increase mitochondrial biogenesis. Since neuronal and endothelial NO synthase (NOS) are calcium dependent and are also phosphorylated by AMPK, we hypothesized that NOS inhibition would attenuate the activation of mitochondrial biogenesis in response to AICAR and caffeine. L6 myotubes either were not treated (control) or were exposed acutely or for 5 h/day over 5 days to 100 microM of N(G)-nitro-L-arginine methyl ester (L-NAME, NOS inhibitor), 100 microM S-nitroso-N-acetyl-penicillamine (SNAP) (NO donor) +/- 100 microM L-NAME, 2 mM AICAR +/- 100 microM L-NAME, or 5 mM caffeine +/- 100 microM L-NAME (n = 12/treatment). Acute AICAR administration increased (P < 0.05) phospho- (P-)AMPK, but also increased P-CaMK, with resultant chronic increases in peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1 alpha), cytochrome-c oxidase (COX)-1, and COX-4 protein expression compared with control cells. NOS inhibition, which had no effect on AICAR-stimulated P-AMPK, surprisingly increased P-CaMK and attenuated the AICAR-induced increases in COX-1 and COX-4 protein. Caffeine administration, which increased P-CaMK without affecting P-AMPK, increased COX-1, COX-4, PGC-1 alpha, and citrate synthase activity. NOS inhibition, surprisingly, greatly attenuated the effect of caffeine on P-CaMK and attenuated the increases in COX-1 and COX-4 protein. SNAP increased all markers of mitochondrial biogenesis, and it also increased P-AMPK and P-CaMK. In conclusion, AICAR and caffeine increase mitochondrial biogenesis in L6 myotubes, at least in part, via interactions with NOS.
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Affiliation(s)
- G K McConell
- Department of Physiology, The University of Melbourne, Parkville, Victoria 3010, Australia.
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41
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Al-Shanti N, Stewart CE. Ca2+/calmodulin-dependent transcriptional pathways: potential mediators of skeletal muscle growth and development. Biol Rev Camb Philos Soc 2009; 84:637-52. [PMID: 19725819 DOI: 10.1111/j.1469-185x.2009.00090.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The loss of muscle mass with age and disuse has a significant impact on the physiological and social well-being of the aged; this is an increasingly important problem as the population becomes skewed towards older age. Exercise has psychological benefits but it also impacts on muscle protein synthesis and degradation, increasing muscle tissue volume in both young and older individuals. Skeletal muscle hypertrophy involves an increase in muscle mass and cross-sectional area and associated increased myofibrillar protein content. Attempts to understand the molecular mechanisms that underlie muscle growth, development and maintenance, have focused on characterising the molecular pathways that initiate, maintain and regenerate skeletal muscle. Such understanding may aid in improving targeted interventional therapies for age-related muscle loss and muscle wasting associated with diseases. Two major routes through which skeletal muscle development and growth are regulated are insulin-like growth factor I (IGF-I) and Ca(2+)/calmodulin-dependent transcriptional pathways. Many reviews have focused on understanding the signalling pathways of IGF-I and its receptor, which govern skeletal muscle hypertrophy. However, alternative molecular signalling pathways such as the Ca(2+)/calmodulin-dependent transcriptional pathways should also be considered as potential mediators of muscle growth. These latter pathways have received relatively little attention and the purpose herein is to highlight the progress being made in the understanding of these pathways and associated molecules: calmodulin, calmodulin kinases (CaMKs), calcineurin and nuclear factor of activated T-cell (NFAT), which are involved in skeletal muscle regulation. We describe: (1) how conformational changes in the Ca(2+) sensor calmodulin result in the exposure of binding pockets for the target proteins (CaMKs and calcineurin). (2) How Calmodulin consequently activates either the Ca(2+)/calmodulin-dependent kinases pathways (via CaMKs) or calmodulin-dependent serine/threonine phosphatases (via calcineurin). (3) How calmodulin kinases alter transcription in the nucleus through the phosphorylation, deactivation and translocation of histone deacetylase 4 (HDAC4) from the nucleus to the cytoplasm. (4) How calcineurin transmits signals to the nucleus through the dephosphorylation and translocation of NFAT from the cytoplasm to the nucleus.
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Affiliation(s)
- Nasser Al-Shanti
- Institute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, John Dalton Building, Oxford Road, Manchester, M1 5GD, UK.
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42
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Baar K. The signaling underlying FITnessThis paper is one of a selection of papers published in this Special Issue, entitled 14th International Biochemistry of Exercise Conference – Muscles as Molecular and Metabolic Machines, and has undergone the Journal’s usual peer review process. Appl Physiol Nutr Metab 2009; 34:411-9. [DOI: 10.1139/h09-035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Exercise results in highly specific physiological adaptations. Resistance exercise increases muscle mass and force production, while endurance exercise increases aerobic capacity. As the physical and chemical signals underlying this specificity become better understood, scientists are beginning to identify the key molecular effectors of exercise specificity. This review focuses on how variations in load, metabolic stress, and calcium flux are transduced to increases in muscle mass and endurance capacity. Specific attention is paid to the mammalian target of rapamycin, AMP-activated protein kinase, and the calcium-calmodulin-activated protein kinases, and the way these proteins interact during concurrent training.
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Affiliation(s)
- Keith Baar
- Division of Molecular Physiology, University of Dundee, James Black Centre, Dow Street, Dundee DD1 5EH, UK (e-mail: )
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43
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Sutherland LN, Bomhof MR, Capozzi LC, Basaraba SAU, Wright DC. Exercise and adrenaline increase PGC-1{alpha} mRNA expression in rat adipose tissue. J Physiol 2009; 587:1607-17. [PMID: 19221126 DOI: 10.1113/jphysiol.2008.165464] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The purpose of the present investigation was to explore the effects of exercise and adrenaline on the mRNA expression of PGC-1alpha, a master regulator of mitochondrial biogenesis, in rat abdominal adipose tissue. We hypothesized that (1) exercise training would increase PGC-1alpha mRNA expression in association with increases in mitochondrial marker enzymes, (2) adrenaline would increase PGC-1alpha mRNA expression and (3) the effect of exercise on PGC-1alpha mRNA expression in white adipose tissue would be attenuated by a beta-blocker. Two hours of daily swim training for 4 weeks led to increases in mitochondrial marker proteins and PGC-1alpha mRNA expression in epididymal and retroperitoneal fat depots. Additionally, a single 2 h bout of exercise led to increases in PGC-1alpha mRNA expression immediately following exercise cessation. Adrenaline treatment of adipose tissue organ cultures led to dose-dependent increases in PGC-1alpha mRNA expression. A supra-physiological concentration of adrenaline increased PGC-1alpha mRNA expression in epididymal but not retroperitoneal adipose tissue. beta-Blockade attenuated the effects of an acute bout of exercise on PGC-1alpha mRNA expression in epididymal but not retroperitoneal fat pads. In summary, this is the first investigation to demonstrate that exercise training, an acute bout of exercise and adrenaline all increase PGC-1alpha mRNA expression in rat white adipose tissue. Furthermore it would appear that increases in circulating catecholamine levels may be one potential mechanism mediating exercise induced increases in PGC-1alpha mRNA expression in rat abdominal adipose tissue.
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44
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Impaired energetics in heart failure — A new therapeutic target. Pharmacol Ther 2008; 119:264-74. [DOI: 10.1016/j.pharmthera.2008.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Accepted: 05/09/2008] [Indexed: 11/20/2022]
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45
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Scarpulla RC. Transcriptional paradigms in mammalian mitochondrial biogenesis and function. Physiol Rev 2008; 88:611-38. [PMID: 18391175 DOI: 10.1152/physrev.00025.2007] [Citation(s) in RCA: 1152] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondria contain their own genetic system and undergo a unique mode of cytoplasmic inheritance. Each organelle has multiple copies of a covalently closed circular DNA genome (mtDNA). The entire protein coding capacity of mtDNA is devoted to the synthesis of 13 essential subunits of the inner membrane complexes of the respiratory apparatus. Thus the majority of respiratory proteins and all of the other gene products necessary for the myriad mitochondrial functions are derived from nuclear genes. Transcription of mtDNA requires a small number of nucleus-encoded proteins including a single RNA polymerase (POLRMT), auxiliary factors necessary for promoter recognition (TFB1M, TFB2M) and activation (Tfam), and a termination factor (mTERF). This relatively simple system can account for the bidirectional transcription of mtDNA from divergent promoters and key termination events controlling the rRNA/mRNA ratio. Nucleomitochondrial interactions depend on the interplay between transcription factors (NRF-1, NRF-2, PPARalpha, ERRalpha, Sp1, and others) and members of the PGC-1 family of regulated coactivators (PGC-1alpha, PGC-1beta, and PRC). The transcription factors target genes that specify the respiratory chain, the mitochondrial transcription, translation and replication machinery, and protein import and assembly apparatus among others. These factors are in turn activated directly or indirectly by PGC-1 family coactivators whose differential expression is controlled by an array of environmental signals including temperature, energy deprivation, and availability of nutrients and growth factors. These transcriptional paradigms provide a basic framework for understanding the integration of mitochondrial biogenesis and function with signaling events that dictate cell- and tissue-specific energetic properties.
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Affiliation(s)
- Richard C Scarpulla
- Department of Cell and Molecular Biology, Northwestern Medical School, Chicago, Illinois 60611, USA
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46
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Hancock CR, Han DH, Chen M, Terada S, Yasuda T, Wright DC, Holloszy JO. High-fat diets cause insulin resistance despite an increase in muscle mitochondria. Proc Natl Acad Sci U S A 2008; 105:7815-20. [PMID: 18509063 PMCID: PMC2409421 DOI: 10.1073/pnas.0802057105] [Citation(s) in RCA: 390] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Indexed: 11/18/2022] Open
Abstract
It has been hypothesized that insulin resistance is mediated by a deficiency of mitochondria in skeletal muscle. In keeping with this hypothesis, high-fat diets that cause insulin resistance have been reported to result in a decrease in muscle mitochondria. In contrast, we found that feeding rats high-fat diets that cause muscle insulin resistance results in a concomitant gradual increase in muscle mitochondria. This adaptation appears to be mediated by activation of peroxisome proliferator-activated receptor (PPAR)delta by fatty acids, which results in a gradual, posttranscriptionally regulated increase in PPAR gamma coactivator 1alpha (PGC-1alpha) protein expression. Similarly, overexpression of PPARdelta results in a large increase in PGC-1alpha protein in the absence of any increase in PGC-1alpha mRNA. We interpret our findings as evidence that raising free fatty acids results in an increase in mitochondria by activating PPARdelta, which mediates a posttranscriptional increase in PGC-1alpha. Our findings argue against the concept that insulin resistance is mediated by a deficiency of muscle mitochondria.
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Affiliation(s)
- Chad R. Hancock
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Dong-Ho Han
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - May Chen
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Shin Terada
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Toshihiro Yasuda
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - David C. Wright
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - John O. Holloszy
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
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47
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Röckl KSC, Witczak CA, Goodyear LJ. Signaling mechanisms in skeletal muscle: acute responses and chronic adaptations to exercise. IUBMB Life 2008; 60:145-53. [PMID: 18380005 DOI: 10.1002/iub.21] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Physical activity elicits physiological responses in skeletal muscle that result in a number of health benefits, in particular in disease states, such as type 2 diabetes. An acute bout of exercise/muscle contraction improves glucose homeostasis by increasing skeletal muscle glucose uptake, while chronic exercise training induces alterations in the expression of metabolic genes, such as those involved in muscle fiber type, mitochondrial biogenesis, or glucose transporter 4 (GLUT4) protein levels. A primary goal of exercise research is to elucidate the mechanisms that regulate these important metabolic and transcriptional events in skeletal muscle. In this review, we briefly summarize the current literature describing the molecular signals underlying skeletal muscle responses to acute and chronic exercise. The search for possible exercise/contraction-stimulated signaling proteins involved in glucose transport, muscle fiber type, and mitochondrial biogenesis is ongoing. Further research is needed because full elucidation of exercise-mediated signaling pathways would represent a significant step toward the development of new pharmacological targets for the treatment of metabolic diseases such as type 2 diabetes.
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Affiliation(s)
- Katja S C Röckl
- Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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48
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Wright DC. Mechanisms of calcium-induced mitochondrial biogenesis and GLUT4 synthesis. Appl Physiol Nutr Metab 2007; 32:840-5. [DOI: 10.1139/h07-062] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Regularly performed aerobic exercise leads to increases in skeletal muscle mitochondria and glucose transporter 4 (GLUT4) protein content, resulting in an enhanced capacity to oxidize substrates and improvements in insulin- and contraction-mediated glucose uptake. Although the specific mechanisms governing these adaptive responses have not been fully elucidated, accumulating evidence suggests that the increase in cytosolic Ca2+ that occurs with each wave of sacrolemmal depolarization is a key component of these processes. Treating L6 muscle cells with agents that increase Ca2+ without causing reductions in ~P or the activation of 5′-AMP-activated protein kinase leads to increases in GLUT4 and mitochondrial protein contents. This effect is likely controlled through calcium/calmodulin-dependent protein kinase (CaMK), since KN93, a specific CaMK inhibitor, blocks these adaptive responses. Recent findings provide evidence that the activation of p38 mitogen-activated protein kinase (MAPK) is involved in the pathway through which Ca2+/CaMK mediates mitochondrial and GLUT4 biogenesis. p38 MAPK initiates GLUT4 and mitochondrial biogenesis through the activation of transcription factors and transcriptional coactivators such as myocyte enhancer factor 2 (MEF2) and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α). Subsequent increases in the content of these proteins further enhance Ca2+-induced GLUT4 and mitochondrial biogenesis. Since decreases in mitochondrial and GLUT4 contents are associated with skeletal muscle insulin resistance, an understanding of the mechanisms by which these processes can be normalized will aid in the prevention and treatment of type 2 diabetes.
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Affiliation(s)
- David C. Wright
- Department of Agriculture, Food and Nutritional Sciences, 4-10 Agriculture/Forestry Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada
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Cantó C, Pich S, Paz JC, Sanches R, Martínez V, Orpinell M, Palacín M, Zorzano A, Gumà A. Neuregulins increase mitochondrial oxidative capacity and insulin sensitivity in skeletal muscle cells. Diabetes 2007; 56:2185-93. [PMID: 17563068 DOI: 10.2337/db06-1726] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Neuregulins are growth factors that are essential for myogenesis and regulate muscle metabolism. The addition of a recombinant neuregulin-1 isoform, heregulin-beta1(177-244) (Hrg), containing 3 nmol/l of the bioactive epidermal growth factor-like domain, to developing L6E9 myocytes has acute and chronic effects on glucose uptake and enhances myogenesis. Here, we studied the metabolic adaptation of myocytes to chronic treatments with Hrg. RESEARCH DESIGN AND METHODS L6E9 and C2C12 myocytes were chronically treated with low concentrations of Hrg (3 pmol/l) that do not induce myogenesis. We analyzed the effects of Hrg on cellular oxidative metabolism and insulin sensitivity and explored the mechanisms of action. RESULTS Hrg increased the cell content of GLUT4 without affecting basal glucose uptake. Glucose and palmitate oxidation increased in Hrg-treated cells, whereas lactate release decreased. Hrg increased the abundance of oxidative phosphorylation (OXPHOS) subunits, enhanced mitochondrial membrane potential, and induced the expression of peroxisome proliferator-activated receptor (PPAR)gamma coactivator1alpha and PPARdelta. Furthermore, we identified PPARdelta as an essential mediator of the stimulatory effects of Hrg on the expression of OXPHOS subunits. The higher oxidative capacity of L6E9 myotubes after neuregulin treatment also paralleled an increase in insulin sensitivity and insulin signaling potency. CONCLUSIONS These results indicate that neuregulins act as key modulators of oxidative capacity and insulin sensitivity in muscle cells.
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Affiliation(s)
- Carles Cantó
- Department of Biochemistry and Molecular Biology, School of Biology, University of Barcelona, Barcelona, Spain
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Guerfali I, Manissolle C, Durieux AC, Bonnefoy R, Bartegi A, Freyssenet D. Calcineurin A and CaMKIV transactivate PGC-1α promoter, but differentially regulate cytochrome c promoter in rat skeletal muscle. Pflugers Arch 2007; 454:297-305. [PMID: 17273866 DOI: 10.1007/s00424-007-0206-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Revised: 12/21/2006] [Accepted: 01/04/2007] [Indexed: 10/23/2022]
Abstract
In skeletal muscle, slow-twitch fibers are highly dependent on mitochondrial oxidative metabolism suggesting the existence of common regulatory pathways in the control of slow muscle-specific protein expression and mitochondrial biogenesis. In this study, we determined whether peroxisome proliferator-activated receptor gamma co-activator-1alpha (PGC-1alpha) could transactivate promoters of nuclear-encoded mitochondrial protein (cytochrome c) and muscle-specific proteins (fast troponin I, MyoD). We also investigated if calcineurin A (CnA) and calcium/calmodulin kinase IV (CaMKIV) were involved in the regulation of PGC-1alpha and cytochrome c promoter. For this purpose, we took advantage of the gene electrotransfer technique, which allows acute expression of a gene of interest. Electrotransfer of a PGC-1alpha expression vector into rat Tibialis anterior muscle induced a strong transactivation of cytochrome c promoter (P < 0.001) independent of nuclear respiratory factor 1. PGC-1alpha gene electrotransfer did not transactivate fast troponin I promoter, whereas it did transactivate MyoD promoter (P < 0.05). Finally, whereas electrotransfers of CnA or CaMKIV expression vectors transactivated PGC-1alpha promoter (P < 0.001), gene electrotransfer of CaMKIV was only able to transactivate cytochrome c promoter. Taken together, these data suggest that CnA triggers PGC-1alpha promoter transactivation to drive the expression of non-mitochondrial proteins.
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Affiliation(s)
- Ibtissem Guerfali
- Unité Physiologie et Physiopathologie de l'Exercice et Handicap EA 3062, Faculté de Médecine, Université Jean Monnet, 15 rue Ambroise Paré, 42023 Saint-Etienne Cedex 2, France
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