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Shabalina IG, Edgar D, Gibanova N, Kalinovich AV, Petrovic N, Vyssokikh MY, Cannon B, Nedergaard J. Enhanced ROS Production in Mitochondria from Prematurely Aging mtDNA Mutator Mice. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:279-298. [PMID: 38622096 DOI: 10.1134/s0006297924020081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/20/2024] [Accepted: 01/21/2024] [Indexed: 04/17/2024]
Abstract
An increase in mitochondrial DNA (mtDNA) mutations and an ensuing increase in mitochondrial reactive oxygen species (ROS) production have been suggested to be a cause of the aging process ("the mitochondrial hypothesis of aging"). In agreement with this, mtDNA-mutator mice accumulate a large amount of mtDNA mutations, giving rise to defective mitochondria and an accelerated aging phenotype. However, incongruously, the rates of ROS production in mtDNA mutator mitochondria have generally earlier been reported to be lower - not higher - than in wildtype, thus apparently invalidating the "mitochondrial hypothesis of aging". We have here re-examined ROS production rates in mtDNA-mutator mice mitochondria. Using traditional conditions for measuring ROS (succinate in the absence of rotenone), we indeed found lower ROS in the mtDNA-mutator mitochondria compared to wildtype. This ROS mainly results from reverse electron flow driven by the membrane potential, but the membrane potential reached in the isolated mtDNA-mutator mitochondria was 33 mV lower than that in wildtype mitochondria, due to the feedback inhibition of succinate oxidation by oxaloacetate, and to a lower oxidative capacity in the mtDNA-mutator mice, explaining the lower ROS production. In contrast, in normal forward electron flow systems (pyruvate (or glutamate) + malate or palmitoyl-CoA + carnitine), mitochondrial ROS production was higher in the mtDNA-mutator mitochondria. Particularly, even during active oxidative phosphorylation (as would be ongoing physiologically), higher ROS rates were seen in the mtDNA-mutator mitochondria than in wildtype. Thus, when examined under physiological conditions, mitochondrial ROS production rates are indeed increased in mtDNA-mutator mitochondria. While this does not prove the validity of the mitochondrial hypothesis of aging, it may no longer be said to be negated in this respect. This paper is dedicated to the memory of Professor Vladimir P. Skulachev.
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Affiliation(s)
- Irina G Shabalina
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Daniel Edgar
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Natalia Gibanova
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Anastasia V Kalinovich
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Natasa Petrovic
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Mikhail Yu Vyssokikh
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Barbara Cannon
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Jan Nedergaard
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, SE-106 91, Sweden.
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Czyżowska A, Brown J, Xu H, Sataranatarajan K, Kinter M, Tyrell VJ, O'Donnell VB, Van Remmen H. Elevated phospholipid hydroperoxide glutathione peroxidase (GPX4) expression modulates oxylipin formation and inhibits age-related skeletal muscle atrophy and weakness. Redox Biol 2023; 64:102761. [PMID: 37279604 PMCID: PMC10276143 DOI: 10.1016/j.redox.2023.102761] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/20/2023] [Accepted: 05/22/2023] [Indexed: 06/08/2023] Open
Abstract
Our previous studies support a key role for mitochondrial lipid hydroperoxides as important contributors to denervation-related muscle atrophy, including muscle atrophy associated with aging. Phospholipid hydroperoxide glutathione peroxidase 4 (GPX4) is an essential antioxidant enzyme that directly reduces phospholipid hydroperoxides and we previously reported that denervation-induced muscle atrophy is blunted in a mouse model of GPX4 overexpression. Therefore, the goal of the present study was to determine whether GPX4 overexpression can reduce the age-related increase in mitochondrial hydroperoxides in skeletal muscle and ameliorate age-related muscle atrophy and weakness (sarcopenia). Male C57Bl6 WT and GPX4 transgenic (GPX4Tg) mice were studied at 3 to 5 and 23-29 months of age. Basal mitochondrial peroxide generation was reduced by 34% in muscle fibers from aged GPX4Tg compared to old WT mice. GPX4 overexpression also reduced levels of lipid peroxidation products: 4-HNE, MDA, and LOOHs by 38%, 32%, and 84% respectively in aged GPX4Tg mice compared to aged WT mice. Muscle mass was preserved in old GPX4 Tg mice by 11% and specific force generation was 21% higher in old GPX4Tg versus age matched male WT mice. Oxylipins from lipoxygenases (LOX) and cyclooxygenase (COX), as well as less abundant non-enzymatically generated isomers, were significantly reduced by GPX4 overexpression. The expression of cPLA2, 12/15-LOX and COX-2 were 1.9-, 10.5- and 3.4-fold greater in old versus young WT muscle respectively, and 12/15-LOX and COX-2 levels were reduced by 37% and 35%, respectively in muscle from old GPX4Tg mice. Our study suggests that lipid peroxidation products may play an important role in the development of sarcopenia, and their detoxification might be an effective intervention in preventing muscle atrophy.
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Affiliation(s)
- Agnieszka Czyżowska
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States
| | - Jacob Brown
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States; Oklahoma City VA Medical Center, Oklahoma City, OK, 73104, United States
| | - Hongyang Xu
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States
| | - Kavitha Sataranatarajan
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States
| | - Michael Kinter
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States
| | - Victoria J Tyrell
- Systems Immunity Research Institute and Division of Infection and Immunity, School of Medicine, Cardiff University, CF14 4XN, UK
| | - Valerie B O'Donnell
- Systems Immunity Research Institute and Division of Infection and Immunity, School of Medicine, Cardiff University, CF14 4XN, UK
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States; Oklahoma City VA Medical Center, Oklahoma City, OK, 73104, United States.
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Cardozo G, Mastrogiovanni M, Zeida A, Viera N, Radi R, Reyes AM, Trujillo M. Mitochondrial Peroxiredoxin 3 Is Rapidly Oxidized and Hyperoxidized by Fatty Acid Hydroperoxides. Antioxidants (Basel) 2023; 12:antiox12020408. [PMID: 36829967 PMCID: PMC9952270 DOI: 10.3390/antiox12020408] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/19/2023] [Accepted: 01/28/2023] [Indexed: 02/11/2023] Open
Abstract
Human peroxiredoxin 3 (HsPrx3) is a thiol-based peroxidase responsible for the reduction of most hydrogen peroxide and peroxynitrite formed in mitochondria. Mitochondrial disfunction can lead to membrane lipoperoxidation, resulting in the formation of lipid-bound fatty acid hydroperoxides (LFA-OOHs) which can be released to become free fatty acid hydroperoxides (fFA-OOHs). Herein, we report that HsPrx3 is oxidized and hyperoxidized by fFA-OOHs including those derived from arachidonic acid and eicosapentaenoic acid peroxidation at position 15 with remarkably high rate constants of oxidation (>3.5 × 107 M-1s-1) and hyperoxidation (~2 × 107 M-1s-1). The endoperoxide-hydroperoxide PGG2, an intermediate in prostanoid synthesis, oxidized HsPrx3 with a similar rate constant, but was less effective in causing hyperoxidation. Biophysical methodologies suggest that HsPrx3 can bind hydrophobic structures. Indeed, molecular dynamic simulations allowed the identification of a hydrophobic patch near the enzyme active site that can allocate the hydroperoxide group of fFA-OOHs in close proximity to the thiolate in the peroxidatic cysteine. Simulations performed using available and herein reported kinetic data indicate that HsPrx3 should be considered a main target for mitochondrial fFA-OOHs. Finally, kinetic simulation analysis support that mitochondrial fFA-OOHs formation fluxes in the range of nM/s are expected to contribute to HsPrx3 hyperoxidation, a modification that has been detected in vivo under physiological and pathological conditions.
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Affiliation(s)
- Giuliana Cardozo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Mauricio Mastrogiovanni
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Ari Zeida
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Nicolás Viera
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Aníbal M. Reyes
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
- Correspondence: (A.M.R.); (M.T.)
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
- Correspondence: (A.M.R.); (M.T.)
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Memme JM, Slavin M, Moradi N, Hood DA. Mitochondrial Bioenergetics and Turnover during Chronic Muscle Disuse. Int J Mol Sci 2021; 22:ijms22105179. [PMID: 34068411 PMCID: PMC8153634 DOI: 10.3390/ijms22105179] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/07/2021] [Accepted: 05/11/2021] [Indexed: 12/15/2022] Open
Abstract
Periods of muscle disuse promote marked mitochondrial alterations that contribute to the impaired metabolic health and degree of atrophy in the muscle. Thus, understanding the molecular underpinnings of muscle mitochondrial decline with prolonged inactivity is of considerable interest. There are translational applications to patients subjected to limb immobilization following injury, illness-induced bed rest, neuropathies, and even microgravity. Studies in these patients, as well as on various pre-clinical rodent models have elucidated the pathways involved in mitochondrial quality control, such as mitochondrial biogenesis, mitophagy, fission and fusion, and the corresponding mitochondrial derangements that underlie the muscle atrophy that ensues from inactivity. Defective organelles display altered respiratory function concurrent with increased accumulation of reactive oxygen species, which exacerbate myofiber atrophy via degradative pathways. The preservation of muscle quality and function is critical for maintaining mobility throughout the lifespan, and for the prevention of inactivity-related diseases. Exercise training is effective in preserving muscle mass by promoting favourable mitochondrial adaptations that offset the mitochondrial dysfunction, which contributes to the declines in muscle and whole-body metabolic health. This highlights the need for further investigation of the mechanisms in which mitochondria contribute to disuse-induced atrophy, as well as the specific molecular targets that can be exploited therapeutically.
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Affiliation(s)
| | | | | | - David A. Hood
- Correspondence: ; Tel.: +1-(416)-736-2100 (ext. 66640)
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Gumucio JP, Qasawa AH, Ferrara PJ, Malik AN, Funai K, McDonagh B, Mendias CL. Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis. FASEB J 2019; 33:7863-7881. [PMID: 30939247 DOI: 10.1096/fj.201802457rr] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Myosteatosis is the pathologic accumulation of lipid that can occur in conjunction with atrophy and fibrosis following skeletal muscle injury. Little is known about the mechanisms by which lipid accumulates in myosteatosis, but many clinical studies have demonstrated that the degree of lipid infiltration negatively correlates with muscle function and regeneration. Our objective was to determine the pathologic changes that result in lipid accumulation in injured muscle fibers. We used a rat model of rotator cuff injury in this study because the rotator cuff muscle group is particularly prone to the development of myosteatosis after injury. Muscles were collected from uninjured controls or 10, 30, or 60 d after injury and analyzed using a combination of muscle fiber contractility assessments, RNA sequencing, and undirected metabolomics, lipidomics, and proteomics, along with bioinformatics techniques to identify potential pathways and cellular processes that are dysregulated after rotator cuff tear. Bioinformatics analyses indicated that mitochondrial function was likely disrupted after injury. Based on these findings and given the role that mitochondria play in lipid metabolism, we then performed targeted biochemical and imaging studies and determined that mitochondrial dysfunction and reduced fatty acid oxidation likely leads to the accumulation of lipid in myosteatosis.-Gumucio, J. P., Qasawa, A. H., Ferrara, P. J., Malik, A. N., Funai, K., McDonagh, B., Mendias, C. L. Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis.
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Affiliation(s)
- Jonathan P Gumucio
- Department of Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Austin H Qasawa
- Department of Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Patrick J Ferrara
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, Utah, USA
| | - Afshan N Malik
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Katsuhiko Funai
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, Utah, USA
| | - Brian McDonagh
- Department of Physiology, School of Medicine, National University of Ireland, Galway, Ireland
| | - Christopher L Mendias
- Department of Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA.,Hospital for Special Surgery, New York, New York, USA.,Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
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6
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Gorgey AS, Witt O, O’Brien L, Cardozo C, Chen Q, Lesnefsky EJ, Graham ZA. Mitochondrial health and muscle plasticity after spinal cord injury. Eur J Appl Physiol 2018; 119:315-331. [DOI: 10.1007/s00421-018-4039-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 11/22/2018] [Indexed: 01/15/2023]
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7
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Li Y, Jie L, Tian AY, Zhong S, Tian MY, Zhong Y, Wang Y, Li H, Li J, Sun X, Du H. Transforming Growth Factor Beta is regulated by a Glucocorticoid-Dependent Mechanism in Denervation Mouse Bone. Sci Rep 2017; 7:9925. [PMID: 28855536 PMCID: PMC5577242 DOI: 10.1038/s41598-017-09793-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 07/28/2017] [Indexed: 01/23/2023] Open
Abstract
Bone growth and remodeling is inhibited by denervation in adults and children, resulting in alterations of linear growth and bone mass and increased risk for osteoporosis and pathologic fractures. Transforming growth factor beta (TGF-β) isoforms are a key group of growth factors that enhance bone formation. To explore the relation between denervation-induced reduction of bone formation and TGF-β gene expression, we measured mRNA levels of TGF-β in denervation mouse bone and found decreased mRNA levels of TGF-β1, TGF-β2 and TGF-β3. These changes were accompanied by diminishing weight loss, bone mineral density (BMD), trabecular thickness, trabecular separation and trabecular number of femur and lumbar, serum osteocalcin, total calcium, intact parathyroid hormone, and increased serum C telopeptide. Recombinant human TGF-β1 (rhTGF-β1) prevented denervation-induced reduction of BMD further supporting our hypothesis that denervation-induced reduction of bone formation is a result of inhibition of TGF-β gene expression. In addition, antiprogestins RU 38486 blunted the denervation-induced decrease in mRNA levels of TGF-β group, while dexamethasone (DEX) decreased TGF-β group mRNA levels in normal mice. Furthermore, the denervated-mice exhibited a threefold increase in plasma corticosterone. These results suggest that denervation-induced reduction of bone formation may be regulated by glucocorticoids via inhibition of TGF-β gene expression at least in part.
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Affiliation(s)
- Ye Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Ligang Jie
- Department of Chinese Medicine, Guangzhou General Hospital of Guangzhou Command, PLA, Guangzhou, China
| | - Austin Y Tian
- Department of Neurology, University of Chicago, Chicago, IL, USA
| | - Shenrong Zhong
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Mason Y Tian
- College of Dentistry, University of New York, New York, NY, USA
| | - Yixiu Zhong
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Yining Wang
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Hongwei Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Jinlong Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China.
| | - Xiaoyan Sun
- Department of Neurology, University of Chicago, Chicago, IL, USA.
| | - Hongyan Du
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China.
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Mukai R, Matsui N, Fujikura Y, Matsumoto N, Hou DX, Kanzaki N, Shibata H, Horikawa M, Iwasa K, Hirasaka K, Nikawa T, Terao J. Preventive effect of dietary quercetin on disuse muscle atrophy by targeting mitochondria in denervated mice. J Nutr Biochem 2016; 31:67-76. [PMID: 27133425 DOI: 10.1016/j.jnutbio.2016.02.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 01/31/2016] [Accepted: 02/01/2016] [Indexed: 12/11/2022]
Abstract
Quercetin is a major dietary flavonoid in fruits and vegetables. We aimed to clarify the preventive effect of dietary quercetin on disuse muscle atrophy and the underlying mechanisms. We established a mouse denervation model by cutting the sciatic nerve in the right leg (SNX surgery) to lack of mobilization in hind-limb. Preintake of a quercetin-mixed diet for 14days before SNX surgery prevented loss of muscle mass and atrophy of muscle fibers in the gastrocnemius muscle (GM). Phosphorylation of Akt, a key phosphorylation pathway of suppression of protein degradation, was activated in the quercetin-mixed diet group with and without SNX surgery. Intake of a quercetin-mixed diet suppressed the generation of hydrogen peroxide originating from mitochondria and elevated mitochondrial peroxisome proliferator-activated receptor-γ coactivator 1α mRNA expression as well as NADH dehydrogenase 4 expression in the GM with SNX surgery. Quercetin and its conjugated metabolites reduced hydrogen peroxide production in the mitochondrial fraction obtained from atrophied muscle. In C2C12 myotubes, quercetin reached the mitochondrial fraction. These findings suggest that dietary quercetin can prevent disuse muscle atrophy by targeting mitochondria in skeletal muscle tissue through protecting mitochondria from decreased biogenesis and reducing mitochondrial hydrogen peroxide release, which can be related to decreased hydrogen peroxide production and/or improvements on antioxidant capacity of mitochondria.
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Affiliation(s)
- Rie Mukai
- Department of Food Science, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramotocho, Tokushima, 770-8503, Japan
| | - Naoko Matsui
- Department of Food Science, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramotocho, Tokushima, 770-8503, Japan
| | - Yutaka Fujikura
- Department of Food Science, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramotocho, Tokushima, 770-8503, Japan
| | - Norifumi Matsumoto
- Department of Biochemical Science and Technology Faculty of Agriculture, Kagoshima University, 1-12-24, Korimoto, Kagoshima, 890-0065, Japan
| | - De-Xing Hou
- Department of Biochemical Science and Technology Faculty of Agriculture, Kagoshima University, 1-12-24, Korimoto, Kagoshima, 890-0065, Japan
| | - Noriyuki Kanzaki
- Institute for Health Care Science, Suntory Wellness Ltd, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Oksaka, 618-8503, Japan
| | - Hiroshi Shibata
- Institute for Health Care Science, Suntory Wellness Ltd, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Oksaka, 618-8503, Japan
| | - Manabu Horikawa
- Bioorganic Research Institute, Suntory Foundation for Life Sciences
| | - Keiko Iwasa
- Research Institute, Suntory Global Innovation Center, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Oksaka, 618-8503, Japan
| | - Katsuya Hirasaka
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan
| | - Takeshi Nikawa
- Department of Nutritional Physiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramotocho, Tokushima, 770-8503, Japan
| | - Junji Terao
- Department of Food Science, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramotocho, Tokushima, 770-8503, Japan.
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Biomolecular bases of the senescence process and cancer. A new approach to oncological treatment linked to ageing. Ageing Res Rev 2015; 23:125-38. [PMID: 25847820 DOI: 10.1016/j.arr.2015.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 03/30/2015] [Indexed: 01/07/2023]
Abstract
Human ageing is associated with a gradual decline in the physiological functions of the body at multiple levels and it is a key risk factor for many diseases, including cancer. Ageing process is intimately related to widespread cellular senescence, characterised by an irreversible loss of proliferative capacity and altered functioning associated with telomere attrition, accumulation of DNA damage and compromised mitochondrial and metabolic function. Tumour and senescent cells may be generated in response to the same stimuli, where either cellular senescence or transformation would constitute two opposite outcomes of the same degenerative process. This paper aims to review the state of knowledge on the biomolecular relationship between cellular senescence, ageing and cancer. Importantly, many of the cell signalling pathways that are found to be altered during both cellular senescence and tumourigenesis are regulated through shared epigenetic mechanisms and, therefore, they are potentially reversible. MicroRNAs are emerging as pivotal players linking ageing and cancer. These small RNA molecules have generated great interest from the point of view of future clinical therapy for cancer because successful experimental results have been obtained in animal models. Micro-RNA therapies for cancer are already being tested in clinical phase trials. These findings have potential importance in cancer treatment in aged people although further research-based knowledge is needed to convert them into an effective molecular therapies for cancer linked to ageing.
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Gonzalez-Freire M, de Cabo R, Bernier M, Sollott SJ, Fabbri E, Navas P, Ferrucci L. Reconsidering the Role of Mitochondria in Aging. J Gerontol A Biol Sci Med Sci 2015; 70:1334-42. [PMID: 25995290 DOI: 10.1093/gerona/glv070] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 04/23/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Mitochondrial dysfunction has long been considered a major contributor to aging and age-related diseases. Harman's Mitochondrial Free Radical Theory of Aging postulated that somatic mitochondrial DNA mutations that accumulate over the life span cause excessive production of reactive oxygen species that damage macromolecules and impair cell and tissue function. Indeed, studies have shown that maximal oxidative capacity declines with age while reactive oxygen species production increases. Harman's hypothesis has been seriously challenged by recent studies showing that reactive oxygen species evoke metabolic health and longevity, perhaps through hormetic mechanisms that include autophagy. The purpose of this review is to scan the ever-growing literature on mitochondria from the perspective of aging research and try to identify priority questions that should be addressed in future research. METHODS A systematic search of peer-reviewed studies was performed using PubMed. Search terms included (i) mitochondria or mitochondrial; (ii) aging, ageing, older adults or elderly; and (iii) reactive oxygen species, mitochondria dynamics, mitochondrial proteostasis, cytosol, mitochondrial-associated membranes, redox homeostasis, electron transport chain, electron transport chain efficiency, epigenetic regulation, DNA heteroplasmy. RESULTS The importance of mitochondrial biology as a trait d'union between the basic biology of aging and the pathogenesis of age-related diseases is stronger than ever, although the emphasis has moved from reactive oxygen species production to other aspects of mitochondrial physiology, including mitochondrial biogenesis and turnover, energy sensing, apoptosis, senescence, and calcium dynamics. CONCLUSIONS Mitochondria could play a key role in the pathophysiology of aging or in the earlier stages of some events that lead to the aging phenotype. Therefore, mitochondria will increasingly be targeted to prevent and treat chronic diseases and to promote healthy aging.
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Affiliation(s)
| | | | | | - Steven J Sollott
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224
| | - Elisa Fabbri
- Translational Gerontology Branch, and Department of Medical and Surgical Sciences, University of Bologna, Italy 40126
| | - Placido Navas
- Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide-CSIC, CIBERER, Instituto de Salud Carlos III, Sevilla, Spain 41013
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11
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Pulliam DA, Deepa SS, Liu Y, Hill S, Lin AL, Bhattacharya A, Shi Y, Sloane L, Viscomi C, Zeviani M, Van Remmen H. Complex IV-deficient Surf1(-/-) mice initiate mitochondrial stress responses. Biochem J 2014; 462:359-71. [PMID: 24911525 PMCID: PMC4145821 DOI: 10.1042/bj20140291] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mutations in SURF1 (surfeit locus protein 1) COX (cytochrome c oxidase) assembly protein are associated with Leigh's syndrome, a human mitochondrial disorder that manifests as severe mitochondrial phenotypes and early lethality. In contrast, mice lacking the SURF1 protein (Surf1-/-) are viable and were previously shown to have enhanced longevity and a greater than 50% reduction in COX activity. We measured mitochondrial function in heart and skeletal muscle, and despite the significant reduction in COX activity, we found little or no difference in ROS (reactive oxygen species) generation, membrane potential, ATP production or respiration in isolated mitochondria from Surf1-/- mice compared with wild-type. However, blood lactate levels were elevated and Surf1-/- mice had reduced running endurance, suggesting compromised mitochondrial energy metabolism in vivo. Decreased COX activity in Surf1-/- mice is associated with increased markers of mitochondrial biogenesis [PGC-1α (peroxisome-proliferator-activated receptor γ co-activator 1α) and VDAC (voltage-dependent anion channel)] in both heart and skeletal muscle. Although mitochondrial biogenesis is a common response in the two tissues, skeletal muscle has an up-regulation of the UPRMT (mitochondrial unfolded protein response) and heart exhibits induction of the Nrf2 (nuclear factor-erythroid 2-related factor 2) antioxidant response pathway. These data are the first to show induction of the UPRMT in a mammalian model of decreased COX activity. In addition, the results of the present study suggest that impaired mitochondrial function can lead to induction of mitochondrial stress pathways to confer protective effects on cellular homoeostasis.
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Affiliation(s)
- Daniel A. Pulliam
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229
| | - Sathyaseelan S. Deepa
- Oklahoma Medical Research Foundation, Free Radical Biology & Aging Research Program, 825NE 13 Street, Oklahoma City, OK 73104
| | - Yuhong Liu
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229
| | - Shauna Hill
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229
| | - Ai-Ling Lin
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229
- Sanders-Brown Center on Aging, Department of Molecular and Biomedical Pharmacology, University of Kentucky
| | - Arunabh Bhattacharya
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229
| | - Yun Shi
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229
| | - Lauren Sloane
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
| | - Carlo Viscomi
- Molecular Neurogenetics Unit, Instituto Neurologico “C. Besta”, via Temolo 4, 20126 Milano, Italy
- MRC-Mitochondrial Biology Unit, Cambridge, UK
| | - Massimo Zeviani
- Molecular Neurogenetics Unit, Instituto Neurologico “C. Besta”, via Temolo 4, 20126 Milano, Italy
- MRC-Mitochondrial Biology Unit, Cambridge, UK
| | - Holly Van Remmen
- Oklahoma Medical Research Foundation, Free Radical Biology & Aging Research Program, 825NE 13 Street, Oklahoma City, OK 73104
- Oklahoma City VA Medical Center, 921 NE 13 Street, Oklahoma City, OK 73104
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12
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Mason S, Wadley GD. Skeletal muscle reactive oxygen species: a target of good cop/bad cop for exercise and disease. Redox Rep 2014; 19:97-106. [PMID: 24620937 PMCID: PMC6837413 DOI: 10.1179/1351000213y.0000000077] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Metabolic stresses associated with disease, ageing, and exercise increase the levels of reactive oxygen species (ROS) in skeletal muscle. These ROS have been linked mechanistically to adaptations in skeletal muscle that can be favourable (i.e. in response to exercise) or detrimental (i.e. in response to disease). The magnitude, duration (acute versus chronic), and cellular origin of the ROS are important underlying factors in determining the metabolic perturbations associated with the ROS produced in skeletal muscle. In particular, insulin resistance has been linked to excess ROS production in skeletal muscle mitochondria. A chronic excess of mitochondrial ROS can impair normal insulin signalling pathways and glucose disposal in skeletal muscle. In contrast, ROS produced in skeletal muscle in response to exercise has been linked to beneficial metabolic adaptations including mitochondrial biogenesis and muscle hypertrophy. Moreover, unlike insulin resistance, exercise-induced ROS appears to be primarily of non-mitochondrial origin. The present review summarizes the diverse ROS-targeted metabolic outcomes associated with insulin resistance versus exercise in skeletal muscle, thus, presenting two contrasting perspectives of pathologically harmful versus physiologically beneficial ROS. Here, we discuss the key sites of ROS production during exercise and the effect of ROS in skeletal muscle of people with type 2 diabetes.
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Affiliation(s)
- Shaun Mason
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Glenn D. Wadley
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
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13
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Szeto HH. First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics. Br J Pharmacol 2014; 171:2029-50. [PMID: 24117165 PMCID: PMC3976620 DOI: 10.1111/bph.12461] [Citation(s) in RCA: 363] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 09/06/2013] [Accepted: 10/01/2013] [Indexed: 12/16/2022] Open
Abstract
A decline in energy is common in aging, and the restoration of mitochondrial bioenergetics may offer a common approach for the treatment of numerous age-associated diseases. Cardiolipin is a unique phospholipid that is exclusively expressed on the inner mitochondrial membrane where it plays an important structural role in cristae formation and the organization of the respiratory complexes into supercomplexes for optimal oxidative phosphorylation. The interaction between cardiolipin and cytochrome c determines whether cytochrome c acts as an electron carrier or peroxidase. Cardiolipin peroxidation and depletion have been reported in a variety of pathological conditions associated with energy deficiency, and cardiolipin has been identified as a target for drug development. This review focuses on the discovery and development of the first cardiolipin-protective compound as a therapeutic agent. SS-31 is a member of the Szeto-Schiller (SS) peptides known to selectively target the inner mitochondrial membrane. SS-31 binds selectively to cardiolipin via electrostatic and hydrophobic interactions. By interacting with cardiolipin, SS-31 prevents cardiolipin from converting cytochrome c into a peroxidase while protecting its electron carrying function. As a result, SS-31 protects the structure of mitochondrial cristae and promotes oxidative phosphorylation. SS-31 represents a new class of compounds that can recharge the cellular powerhouse and restore bioenergetics. Extensive animal studies have shown that targeting such a fundamental mechanism can benefit highly complex diseases that share a common pathogenesis of bioenergetics failure. This review summarizes the mechanisms of action and therapeutic potential of SS-31 and provides an update of its clinical development programme.
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Affiliation(s)
- Hazel H Szeto
- Research Program in Mitochondrial Therapeutics, Department of Pharmacology, Joan and Sanford I. Weill Medical College of Cornell UniversityNew York, NY, USA
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14
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Muscogiuri G, Salmon AB, Aguayo-Mazzucato C, Li M, Balas B, Guardado-Mendoza R, Giaccari A, Reddick RL, Reyna SM, Weir G, DeFronzo RA, Van Remmen H, Musi N. Genetic disruption of SOD1 gene causes glucose intolerance and impairs β-cell function. Diabetes 2013; 62:4201-7. [PMID: 24009256 PMCID: PMC3837066 DOI: 10.2337/db13-0314] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Oxidative stress has been associated with insulin resistance and type 2 diabetes. However, it is not clear whether oxidative damage is a cause or a consequence of the metabolic abnormalities present in diabetic subjects. The goal of this study was to determine whether inducing oxidative damage through genetic ablation of superoxide dismutase 1 (SOD1) leads to abnormalities in glucose homeostasis. We studied SOD1-null mice and wild-type (WT) littermates. Glucose tolerance was evaluated with intraperitoneal glucose tolerance tests. Peripheral and hepatic insulin sensitivity was quantitated with the euglycemic-hyperinsulinemic clamp. β-Cell function was determined with the hyperglycemic clamp and morphometric analysis of pancreatic islets. Genetic ablation of SOD1 caused glucose intolerance, which was associated with reduced in vivo β-cell insulin secretion and decreased β-cell volume. Peripheral and hepatic insulin sensitivity were not significantly altered in SOD1-null mice. High-fat diet caused glucose intolerance in WT mice but did not further worsen the glucose intolerance observed in standard chow-fed SOD1-null mice. Our findings suggest that oxidative stress per se does not play a major role in the pathogenesis of insulin resistance and demonstrate that oxidative stress caused by SOD1 ablation leads to glucose intolerance secondary to β-cell dysfunction.
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Affiliation(s)
- Giovanna Muscogiuri
- Diabetes Division, University of Texas Health Science Center, San Antonio, Texas
| | - Adam B. Salmon
- Barshop Institute for Longevity and Aging Studies, San Antonio, Texas
- Geriatric Research, Education, and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas
| | | | - Mengyao Li
- Diabetes Division, University of Texas Health Science Center, San Antonio, Texas
| | - Bogdan Balas
- Diabetes Division, University of Texas Health Science Center, San Antonio, Texas
| | | | - Andrea Giaccari
- Division of Endocrinology and Metabolic Diseases, Università Cattolica del Sacro Cuore, Policlinico “A. Gemelli,” Rome, and Fondazione Don Gnocchi, Milan, Italy
| | - Robert L. Reddick
- Department of Pathology, University of Texas Health Science Center, San Antonio, Texas
| | - Sara M. Reyna
- Diabetes Division, University of Texas Health Science Center, San Antonio, Texas
| | - Gordon Weir
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, Massachusetts
| | - Ralph A. DeFronzo
- Diabetes Division, University of Texas Health Science Center, San Antonio, Texas
| | - Holly Van Remmen
- Barshop Institute for Longevity and Aging Studies, San Antonio, Texas
- Geriatric Research, Education, and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas
| | - Nicolas Musi
- Diabetes Division, University of Texas Health Science Center, San Antonio, Texas
- Barshop Institute for Longevity and Aging Studies, San Antonio, Texas
- Geriatric Research, Education, and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas
- Corresponding author: Nicolas Musi,
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15
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Calvani R, Joseph AM, Adhihetty PJ, Miccheli A, Bossola M, Leeuwenburgh C, Bernabei R, Marzetti E. Mitochondrial pathways in sarcopenia of aging and disuse muscle atrophy. Biol Chem 2013; 394:393-414. [PMID: 23154422 DOI: 10.1515/hsz-2012-0247] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 11/13/2012] [Indexed: 12/18/2022]
Abstract
Muscle loss during aging and disuse is a highly prevalent and disabling condition, but knowledge about cellular pathways mediating muscle atrophy is still limited. Given the postmitotic nature of skeletal myocytes, the maintenance of cellular homeostasis relies on the efficiency of cellular quality control mechanisms. In this scenario, alterations in mitochondrial function are considered a major factor underlying sarcopenia and muscle atrophy. Damaged mitochondria are not only less bioenergetically efficient, but also generate increased amounts of reactive oxygen species, interfere with cellular quality control mechanisms, and display a greater propensity to trigger apoptosis. Thus, mitochondria stand at the crossroad of signaling pathways that regulate skeletal myocyte function and viability. Studies on these pathways have sometimes provided unexpected and counterintuitive results, which suggests that they are organized into a complex, heterarchical network that is currently insufficiently understood. Untangling the complexity of such a network will likely provide clinicians with novel and highly effective therapeutics to counter the muscle loss associated with aging and disuse. In this review, we summarize the current knowledge on the mechanisms whereby mitochondrial dysfunction intervenes in the pathogenesis of sarcopenia and disuse atrophy, and highlight the prospect of targeting specific processes to treat these conditions.
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Affiliation(s)
- Riccardo Calvani
- Institute of Crystallography, Italian National Research Council (CNR), Bari 70126, Italy
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16
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Oxidative damage associated with obesity is prevented by overexpression of CuZn- or Mn-superoxide dismutase. Biochem Biophys Res Commun 2013; 438:78-83. [PMID: 23872067 DOI: 10.1016/j.bbrc.2013.07.029] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 07/09/2013] [Indexed: 11/22/2022]
Abstract
The development of insulin resistance is the primary step in the etiology of type 2 diabetes mellitus. There are several risk factors associated with insulin resistance, yet the basic biological mechanisms that promote its development are still unclear. There is growing literature that suggests mitochondrial dysfunction and/or oxidative stress play prominent roles in defects in glucose metabolism. Here, we tested whether increased expression of CuZn-superoxide dismutase (Sod1) or Mn-superoxide dismutase (Sod2) prevented obesity-induced changes in oxidative stress and metabolism. Both Sod1 and Sod2 overexpressing mice were protected from high fat diet-induced glucose intolerance. Lipid oxidation (F2-isoprostanes) was significantly increased in muscle and adipose with high fat feeding. Mice with increased expression of either Sod1 or Sod2 showed a significant reduction in this oxidative damage. Surprisingly, mitochondria from the muscle of high fat diet-fed mice showed no significant alteration in function. Together, our data suggest that targeting reduced oxidative damage in general may be a more applicable therapeutic target to prevent insulin resistance than is improving mitochondrial function.
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17
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Mukai R, Terao J. Role of dietary flavonoids in oxidative stress and prevention of muscle atrophy. THE JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2013. [DOI: 10.7600/jpfsm.2.385] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Powers SK, Wiggs MP, Duarte JA, Zergeroglu AM, Demirel HA. Mitochondrial signaling contributes to disuse muscle atrophy. Am J Physiol Endocrinol Metab 2012; 303:E31-9. [PMID: 22395111 PMCID: PMC3404565 DOI: 10.1152/ajpendo.00609.2011] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
It is well established that long durations of bed rest, limb immobilization, or reduced activity in respiratory muscles during mechanical ventilation results in skeletal muscle atrophy in humans and other animals. The idea that mitochondrial damage/dysfunction contributes to disuse muscle atrophy originated over 40 years ago. These early studies were largely descriptive and did not provide unequivocal evidence that mitochondria play a primary role in disuse muscle atrophy. However, recent experiments have provided direct evidence connecting mitochondrial dysfunction to muscle atrophy. Numerous studies have described changes in mitochondria shape, number, and function in skeletal muscles exposed to prolonged periods of inactivity. Furthermore, recent evidence indicates that increased mitochondrial ROS production plays a key signaling role in both immobilization-induced limb muscle atrophy and diaphragmatic atrophy occurring during prolonged mechanical ventilation. Moreover, new evidence reveals that, during denervation-induced muscle atrophy, increased mitochondrial fragmentation due to fission is a required signaling event that activates the AMPK-FoxO3 signaling axis, which induces the expression of atrophy genes, protein breakdown, and ultimately muscle atrophy. Collectively, these findings highlight the importance of future research to better understand the mitochondrial signaling mechanisms that contribute to disuse muscle atrophy and to develop novel therapeutic interventions for prevention of inactivity-induced skeletal muscle atrophy.
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Affiliation(s)
- Scott K Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
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19
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Wei R, Bhattacharya A, Chintalaramulu N, Jernigan AL, Liu Y, Van Remmen H, Chaudhuri AR. Protein misfolding, mitochondrial dysfunction and muscle loss are not directly dependent on soluble and aggregation state of mSOD1 protein in skeletal muscle of ALS. Biochem Biophys Res Commun 2012; 417:1275-9. [PMID: 22234310 DOI: 10.1016/j.bbrc.2011.12.126] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 12/25/2011] [Indexed: 12/01/2022]
Abstract
Mutant superoxide dismutase 1 (mSOD1) is often found as aggregates at the outer-membrane of mitochondria in motor neurons of various mouse models and familial amyotrophic lateral sclerosis (f-ALS) patients. It has been postulated that disruption of mitochondrial function by physical association of misfolded mSOD1 aggregates may actually be the trigger for initiation of degeneration of motor neurons in ALS. However, it was not clear if the same mechanism is involved in muscle degeneration and mitochondrial dysfunction in skeletal muscles of ALS. Recent study from our laboratory show that two skeletal muscle proteins, namely creatine kinase (CK) and glyceraldehydes-3-phosphate dehydrogenase (GAPDH) undergo major conformational and functional changes in the f-ALS mouse model of ALS (G93A). In this paper, we report two intriguing observations which are as follows:(i) G93A protein does not form aggregates in skeletal muscle at any stages of disease process probably due to high chymotrypsin-like activity of proteasome and thus G93A protein aggregates have no direct effects on progressive loss of muscle mass and global changes in protein conformation in ALS, and (ii) the soluble G93A protein does not have direct effects on mitochondrial dysfunction as determined by quantifying the release of reactive oxygen species (ROS) in skeletal muscle mitochondria; instead, the proteins affected by G93A possibly affect mitochondrial ROS release. These data strongly suggest for the first time that unlike in motor neurons, the soluble and aggregation states of the G93A protein do not have direct effects on protein misfolding and mitochondrial dysfunction in skeletal muscle during ALS.
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Affiliation(s)
- Rochelle Wei
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, TX 78229-3900, USA
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