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Vongthip W, Nilkhet S, Boonruang K, Sukprasansap M, Tencomnao T, Baek SJ. Neuroprotective mechanisms of luteolin in glutamate-induced oxidative stress and autophagy-mediated neuronal cell death. Sci Rep 2024; 14:7707. [PMID: 38565590 PMCID: PMC10987666 DOI: 10.1038/s41598-024-57824-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 03/21/2024] [Indexed: 04/04/2024] Open
Abstract
Neurodegenerative diseases, characterized by progressive neuronal dysfunction and loss, pose significant health challenges. Glutamate accumulation contributes to neuronal cell death in diseases such as Alzheimer's disease. This study investigates the neuroprotective potential of Albizia lebbeck leaf extract and its major constituent, luteolin, against glutamate-induced hippocampal neuronal cell death. Glutamate-treated HT-22 cells exhibited reduced viability, altered morphology, increased ROS, and apoptosis, which were attenuated by pre-treatment with A. lebbeck extract and luteolin. Luteolin also restored mitochondrial function, decreased mitochondrial superoxide, and preserved mitochondrial morphology. Notably, we first found that luteolin inhibited the excessive process of mitophagy via the inactivation of BNIP3L/NIX and inhibited lysosomal activity. Our study suggests that glutamate-induced autophagy-mediated cell death is attenuated by luteolin via activation of mTORC1. These findings highlight the potential of A. lebbeck as a neuroprotective agent, with luteolin inhibiting glutamate-induced neurotoxicity by regulating autophagy and mitochondrial dynamics.
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Affiliation(s)
- Wudtipong Vongthip
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Program in Clinical Biochemistry and Molecular Medicine, Chulalongkorn University, 10330, Bangkok, Thailand
- Laboratory of Signal Transduction, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Sunita Nilkhet
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Program in Clinical Biochemistry and Molecular Medicine, Chulalongkorn University, 10330, Bangkok, Thailand
- Laboratory of Signal Transduction, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Kanokkan Boonruang
- Laboratory of Signal Transduction, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Monruedee Sukprasansap
- Food Toxicology Unit, Institute of Nutrition, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Tewin Tencomnao
- Natural Products for Neuroprotection and Anti-Ageing Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand.
| | - Seung Joon Baek
- Laboratory of Signal Transduction, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea.
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2
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Hammoud S, Ivanova A, Osaki Y, Funk S, Yang H, Viquez O, Delgado R, Lu D, Phillips Mignemi M, Tonello J, Colon S, Lantier L, Wasserman DH, Humphreys BD, Koenitzer J, Kern J, de Caestecker M, Finkel T, Fogo A, Messias N, Lodhi IJ, Gewin LS. Tubular CPT1A deletion minimally affects aging and chronic kidney injury. JCI Insight 2024; 9:e171961. [PMID: 38516886 PMCID: PMC11063933 DOI: 10.1172/jci.insight.171961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 02/14/2024] [Indexed: 03/23/2024] Open
Abstract
Kidney tubules use fatty acid oxidation (FAO) to support their high energetic requirements. Carnitine palmitoyltransferase 1A (CPT1A) is the rate-limiting enzyme for FAO, and it is necessary to transport long-chain fatty acids into mitochondria. To define the role of tubular CPT1A in aging and injury, we generated mice with tubule-specific deletion of Cpt1a (Cpt1aCKO mice), and the mice were either aged for 2 years or injured by aristolochic acid or unilateral ureteral obstruction. Surprisingly, Cpt1aCKO mice had no significant differences in kidney function or fibrosis compared with wild-type mice after aging or chronic injury. Primary tubule cells from aged Cpt1aCKO mice had a modest decrease in palmitate oxidation but retained the ability to metabolize long-chain fatty acids. Very-long-chain fatty acids, exclusively oxidized by peroxisomes, were reduced in kidneys lacking tubular CPT1A, consistent with increased peroxisomal activity. Single-nuclear RNA-Seq showed significantly increased expression of peroxisomal FAO enzymes in proximal tubules of mice lacking tubular CPT1A. These data suggest that peroxisomal FAO may compensate in the absence of CPT1A, and future genetic studies are needed to confirm the role of peroxisomal β-oxidation when mitochondrial FAO is impaired.
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Affiliation(s)
- Safaa Hammoud
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Alla Ivanova
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Yosuke Osaki
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Steven Funk
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Haichun Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Olga Viquez
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Rachel Delgado
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Dongliang Lu
- Division of Endocrinology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Jane Tonello
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Selene Colon
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Louise Lantier
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - David H. Wasserman
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Benjamin D. Humphreys
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jeffrey Koenitzer
- Division of Pulmonary Critical Care Medicine, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Justin Kern
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Toren Finkel
- Aging Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Agnes Fogo
- Division of Nephrology and Hypertension, Department of Medicine, and
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Nidia Messias
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Irfan J. Lodhi
- Division of Endocrinology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Leslie S. Gewin
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Nephrology and Hypertension, Department of Medicine, and
- Department of Medicine, Veterans Affairs Hospital, St. Louis, Missouri, USA
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3
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Sato K, Satoshi Y, Miyauchi Y, Sato F, Kon R, Ikarashi N, Chiba Y, Hosoe T, Sakai H. Downregulation of PGC-1α during cisplatin-induced muscle atrophy in murine skeletal muscle. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166877. [PMID: 37673360 DOI: 10.1016/j.bbadis.2023.166877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 07/20/2023] [Accepted: 08/31/2023] [Indexed: 09/08/2023]
Abstract
This study aimed to investigate the effects of cisplatin on adenosine triphosphate (ATP) levels, expressions of genes related to mitochondrial oxidative phosphorylation (OXPHOS), and the factors related to mitochondrial biosynthesis in skeletal muscle. Systemic cisplatin administration decreased skeletal muscle mass, skeletal muscle strength, and endurance. The mitochondrial DNA /nuclear DNA ratio was also reduced after treatment with cisplatin. Moreover, among the factors related to mitochondrial biogenesis and function, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) was significantly downregulated in the cisplatin-treated group. Downregulation of PGC-1α in the skeletal muscle may contribute to muscle weakness during cisplatin-induced muscle atrophy.
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Affiliation(s)
- Ken Sato
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Yoshida Satoshi
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Yu Miyauchi
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Fumiaki Sato
- Department of Analytical Pathophysiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Risako Kon
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Nobutomo Ikarashi
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Yoshihiko Chiba
- Department of Physiology and Molecular Sciences, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Tomoo Hosoe
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan; Department of Bioregulatory Science, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan
| | - Hiroyasu Sakai
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501, Japan.
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Shammas MK, Nie Y, Gilsrud A, Huang X, Narendra DP, Chinnery PF. CHCHD10 mutations induce tissue-specific mitochondrial DNA deletions with a distinct signature. Hum Mol Genet 2023; 33:91-101. [PMID: 37815936 PMCID: PMC10729859 DOI: 10.1093/hmg/ddad161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/11/2023] [Accepted: 09/19/2023] [Indexed: 10/12/2023] Open
Abstract
Mutations affecting the mitochondrial intermembrane space protein CHCHD10 cause human disease, but it is not known why different amino acid substitutions cause markedly different clinical phenotypes, including amyotrophic lateral sclerosis-frontotemporal dementia, spinal muscular atrophy Jokela-type, isolated autosomal dominant mitochondrial myopathy and cardiomyopathy. CHCHD10 mutations have been associated with deletions of mitochondrial DNA (mtDNA deletions), raising the possibility that these explain the clinical variability. Here, we sequenced mtDNA obtained from hearts, skeletal muscle, livers and spinal cords of WT and Chchd10 G58R or S59L knockin mice to characterise the mtDNA deletion signatures of the two mutant lines. We found that the deletion levels were higher in G58R and S59L mice than in WT mice in some tissues depending on the Chchd10 genotype, and the deletion burden increased with age. Furthermore, we observed that the spinal cord was less prone to the development of mtDNA deletions than the other tissues examined. Finally, in addition to accelerating the rate of naturally occurring deletions, Chchd10 mutations also led to the accumulation of a novel set of deletions characterised by shorter direct repeats flanking the deletion breakpoints. Our results indicate that Chchd10 mutations in mice induce tissue-specific deletions which may also contribute to the clinical phenotype associated with these mutations in humans.
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Affiliation(s)
- Mario K Shammas
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, United Kingdom
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Yu Nie
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, United Kingdom
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Alexandra Gilsrud
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Xiaoping Huang
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Derek P Narendra
- Inherited Movement Disorders Unit, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, United States
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, United Kingdom
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
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Wang BYH, Hsiao AWT, Wong N, Chen YF, Lee CW, Lee WYW. Is dexamethasone-induced muscle atrophy an alternative model for naturally aged sarcopenia model? J Orthop Translat 2022; 39:12-20. [PMID: 36605620 PMCID: PMC9793312 DOI: 10.1016/j.jot.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 11/10/2022] [Accepted: 11/15/2022] [Indexed: 12/24/2022] Open
Abstract
Background Primary sarcopenia is usually known as age-related skeletal muscle loss; however, other factors like endocrine, lifestyle and inflammation can also cause muscle loss, known as secondary sarcopenia. Although many studies have used different sarcopenia animal models for exploring the underlying mechanism and therapeutic approaches for sarcopenia, limited study has provided evidence of the relevance of these animal models. This study aims to investigate the similarity and difference in muscle qualities between primary and secondary sarcopenia mice models, using naturally aged mice and dexamethasone-induced mice. Methods 21-month-old mice were used as naturally aged primary sarcopenia mice and 3-month-old mice received daily intraperitoneal injection of dexamethasone (20 mg/ kg body weight) for 10 days were used as secondary sarcopenia model. This study provided measurements for muscle mass and functions, including Dual-energy X-ray absorptiometry (DXA) scanning, handgrip strength test and treadmill running to exhaustion test. Besides, muscle contraction, muscle fibre type measurements and gene expression were also performed to provide additional information on muscle qualities. Results The results suggest two sarcopenia animal models shared a comparable decrease in forelimb lean mass, muscle fibre size, grip strength and muscle contraction ability. Besides, the upregulation of protein degradation genes was also observed in two sarcopenia animal models. However, only primary sarcopenia mice were identified with an early stage of mtDNA deletion. Conclusion Collectively, this study evaluated that the dexamethasone-induced mouse model could be served as an alternative model for primary sarcopenia, according to the comparable muscle mass and functional changes. However, whether dexamethasone-induced mice can be used as an animal model when studying the molecular mechanisms of sarcopenia needs to be carefully evaluated. The translational potential of this article The purpose of sarcopenia research is to investigate appropriate treatments for reversing the loss of skeletal muscle mass and functions. Using animal models for the preclinical study could predict the safety and efficacy of the treatments. This study compared the typical age-related sarcopenia mice model and dexamethasone-induced secondary sarcopenia mice to provide evidence of the pathological and functional changes in the mice models.
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Affiliation(s)
- Belle Yu-Hsuan Wang
- Department of Orthopaedics and Traumatology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong,Center for Neuromusculoskeletal Restorative Medicine, CUHK InnoHK Centres, Hong Kong Science Park, Hong Kong
| | - Allen Wei-Ting Hsiao
- Department of Orthopaedics and Traumatology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Nicodemus Wong
- Department of Orthopaedics and Traumatology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong,Center for Neuromusculoskeletal Restorative Medicine, CUHK InnoHK Centres, Hong Kong Science Park, Hong Kong
| | - Yi-Fan Chen
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11529, Taiwan,Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, 11031 Taipei, Taiwan,Master Program in Clinical Genomics and Proteomics, School of Pharmacy, Taipei Medical University, Taipei, 11031, Taiwan,International Ph.D. Program for Translational Science, College of Medical Science and Technology, Taipei Medical University, 11031 Taipei, Taiwan
| | - Chien-Wei Lee
- Center for Translational Genomics & Regenerative Medicine Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan,Corresponding author.
| | - Wayne Yuk Wai Lee
- Department of Orthopaedics and Traumatology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong,Center for Neuromusculoskeletal Restorative Medicine, CUHK InnoHK Centres, Hong Kong Science Park, Hong Kong,Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong,SH Ho Scoliosis Research Laboratory, Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, The Chinese University of Hong Kong, Shatin, Hong Kong,Corresponding author. Department of Orthopaedics and Traumatology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
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Sanchez MM, Bagdasarian IA, Darch W, Morgan JT. Organotypic cultures as aging associated disease models. Aging (Albany NY) 2022; 14:9338-9383. [PMID: 36435511 PMCID: PMC9740367 DOI: 10.18632/aging.204361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 10/21/2022] [Indexed: 11/24/2022]
Abstract
Aging remains a primary risk factor for a host of diseases, including leading causes of death. Aging and associated diseases are inherently multifactorial, with numerous contributing factors and phenotypes at the molecular, cellular, tissue, and organismal scales. Despite the complexity of aging phenomena, models currently used in aging research possess limitations. Frequently used in vivo models often have important physiological differences, age at different rates, or are genetically engineered to match late disease phenotypes rather than early causes. Conversely, routinely used in vitro models lack the complex tissue-scale and systemic cues that are disrupted in aging. To fill in gaps between in vivo and traditional in vitro models, researchers have increasingly been turning to organotypic models, which provide increased physiological relevance with the accessibility and control of in vitro context. While powerful tools, the development of these models is a field of its own, and many aging researchers may be unaware of recent progress in organotypic models, or hesitant to include these models in their own work. In this review, we describe recent progress in tissue engineering applied to organotypic models, highlighting examples explicitly linked to aging and associated disease, as well as examples of models that are relevant to aging. We specifically highlight progress made in skin, gut, and skeletal muscle, and describe how recently demonstrated models have been used for aging studies or similar phenotypes. Throughout, this review emphasizes the accessibility of these models and aims to provide a resource for researchers seeking to leverage these powerful tools.
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Affiliation(s)
- Martina M. Sanchez
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
| | | | - William Darch
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
| | - Joshua T. Morgan
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
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7
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Gureev AP, Andrianova NV, Pevzner IB, Zorova LD, Chernyshova EV, Sadovnikova IS, Chistyakov DV, Popkov VA, Semenovich DS, Babenko VA, Silachev DN, Zorov DB, Plotnikov EY, Popov VN. Dietary restriction modulates mitochondrial DNA damage and oxylipin profile in aged rats. FEBS J 2022; 289:5697-5713. [DOI: 10.1111/febs.16451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/16/2022] [Accepted: 04/01/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Artem P. Gureev
- Department of Genetics, Cytology and Bioengineering Voronezh State University Voronezh Russia
- Laboratory of Metagenomics and Food Biotechnology Voronezh State University of Engineering Technology Voronezh Russia
| | - Nadezda V. Andrianova
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
| | - Irina B. Pevzner
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- Kulakov National Medical Research Center of Obstetrics, Gynecology, and Perinatology Moscow Russia
| | - Ljubava D. Zorova
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- Kulakov National Medical Research Center of Obstetrics, Gynecology, and Perinatology Moscow Russia
| | | | - Irina S. Sadovnikova
- Department of Genetics, Cytology and Bioengineering Voronezh State University Voronezh Russia
| | - Dmitry V. Chistyakov
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
| | - Vasily A. Popkov
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- Kulakov National Medical Research Center of Obstetrics, Gynecology, and Perinatology Moscow Russia
| | - Dmitry S. Semenovich
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
| | - Valentina A. Babenko
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- Kulakov National Medical Research Center of Obstetrics, Gynecology, and Perinatology Moscow Russia
| | - Denis N. Silachev
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- Kulakov National Medical Research Center of Obstetrics, Gynecology, and Perinatology Moscow Russia
| | - Dmitry B. Zorov
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- Kulakov National Medical Research Center of Obstetrics, Gynecology, and Perinatology Moscow Russia
| | - Egor Y. Plotnikov
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- Kulakov National Medical Research Center of Obstetrics, Gynecology, and Perinatology Moscow Russia
| | - Vasily N. Popov
- Department of Genetics, Cytology and Bioengineering Voronezh State University Voronezh Russia
- Laboratory of Metagenomics and Food Biotechnology Voronezh State University of Engineering Technology Voronezh Russia
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8
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Čater M, Bombek LK. Protective Role of Mitochondrial Uncoupling Proteins against Age-Related Oxidative Stress in Type 2 Diabetes Mellitus. Antioxidants (Basel) 2022; 11:antiox11081473. [PMID: 36009191 PMCID: PMC9404801 DOI: 10.3390/antiox11081473] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 02/04/2023] Open
Abstract
The accumulation of oxidative damage to DNA and other biomolecules plays an important role in the etiology of aging and age-related diseases such as type 2 diabetes mellitus (T2D), atherosclerosis, and neurodegenerative disorders. Mitochondrial DNA (mtDNA) is especially sensitive to oxidative stress. Mitochondrial dysfunction resulting from the accumulation of mtDNA damage impairs normal cellular function and leads to a bioenergetic crisis that accelerates aging and associated diseases. Age-related mitochondrial dysfunction decreases ATP production, which directly affects insulin secretion by pancreatic beta cells and triggers the gradual development of the chronic metabolic dysfunction that characterizes T2D. At the same time, decreased glucose oxidation in skeletal muscle due to mitochondrial damage leads to prolonged postprandial blood glucose rise, which further worsens glucose homeostasis. ROS are not only highly reactive by-products of mitochondrial respiration capable of oxidizing DNA, proteins, and lipids but can also function as signaling and effector molecules in cell membranes mediating signal transduction and inflammation. Mitochondrial uncoupling proteins (UCPs) located in the inner mitochondrial membrane of various tissues can be activated by ROS to protect cells from mitochondrial damage. Mitochondrial UCPs facilitate the reflux of protons from the mitochondrial intermembrane space into the matrix, thereby dissipating the proton gradient required for oxidative phosphorylation. There are five known isoforms (UCP1-UCP5) of mitochondrial UCPs. UCP1 can indirectly reduce ROS formation by increasing glutathione levels, thermogenesis, and energy expenditure. In contrast, UCP2 and UCP3 regulate fatty acid metabolism and insulin secretion by beta cells and modulate insulin sensitivity. Understanding the functions of UCPs may play a critical role in developing pharmacological strategies to combat T2D. This review summarizes the current knowledge on the protective role of various UCP homologs against age-related oxidative stress in T2D.
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Affiliation(s)
- Maša Čater
- Correspondence: (M.Č.); (L.K.B.); Tel.: +386-2-2345-847 (L.K.B.)
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9
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Barbiera A, Sorrentino S, Fard D, Lepore E, Sica G, Dobrowolny G, Tamagnone L, Scicchitano BM. Taurine Administration Counteracts Aging-Associated Impingement of Skeletal Muscle Regeneration by Reducing Inflammation and Oxidative Stress. Antioxidants (Basel) 2022; 11:antiox11051016. [PMID: 35624880 PMCID: PMC9137670 DOI: 10.3390/antiox11051016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 02/05/2023] Open
Abstract
Sarcopenia, which occurs during aging, is characterized by the gradual loss of skeletal muscle mass and function, resulting in a functional decline in physical abilities. Several factors contribute to the onset of sarcopenia, including reduced regenerative capacity, chronic low-grade inflammation, mitochondrial dysfunction, and increased oxidative stress, leading to the activation of catabolic pathways. Physical activity and adequate protein intake are considered effective strategies able to reduce the incidence and severity of sarcopenia by exerting beneficial effects in improving the muscular anabolic response during aging. Taurine is a non-essential amino acid that is highly expressed in mammalian tissues and, particularly, in skeletal muscle where it is involved in the regulation of biological processes and where it acts as an antioxidant and anti-inflammatory factor. Here, we evaluated whether taurine administration in old mice counteracts the physiopathological effects of aging in skeletal muscle. We showed that, in injured muscle, taurine enhances the regenerative process by downregulating the inflammatory response and preserving muscle fiber integrity. Moreover, taurine attenuates ROS production in aged muscles by maintaining a proper cellular redox balance, acting as an antioxidant molecule. Although further studies are needed to better elucidate the molecular mechanisms responsible for the beneficial effect of taurine on skeletal muscle homeostasis, these data demonstrate that taurine administration ameliorates the microenvironment allowing an efficient regenerative process and attenuation of the catabolic pathways related to the onset of sarcopenia.
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Affiliation(s)
- Alessandra Barbiera
- Sezione di Istologia ed Embriologia, Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, L.go Francesco Vito 1, 00168 Roma, Italy; (A.B.); (S.S.); (D.F.); (G.S.); (L.T.)
- Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go Francesco Vito 1, 00168 Roma, Italy
| | - Silvia Sorrentino
- Sezione di Istologia ed Embriologia, Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, L.go Francesco Vito 1, 00168 Roma, Italy; (A.B.); (S.S.); (D.F.); (G.S.); (L.T.)
| | - Damon Fard
- Sezione di Istologia ed Embriologia, Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, L.go Francesco Vito 1, 00168 Roma, Italy; (A.B.); (S.S.); (D.F.); (G.S.); (L.T.)
| | - Elisa Lepore
- DAHFMO-Unità di Istologia ed Embriologia Medica, Sapienza Università di Roma, 00161 Roma, Italy; (E.L.); (G.D.)
| | - Gigliola Sica
- Sezione di Istologia ed Embriologia, Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, L.go Francesco Vito 1, 00168 Roma, Italy; (A.B.); (S.S.); (D.F.); (G.S.); (L.T.)
| | - Gabriella Dobrowolny
- DAHFMO-Unità di Istologia ed Embriologia Medica, Sapienza Università di Roma, 00161 Roma, Italy; (E.L.); (G.D.)
| | - Luca Tamagnone
- Sezione di Istologia ed Embriologia, Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, L.go Francesco Vito 1, 00168 Roma, Italy; (A.B.); (S.S.); (D.F.); (G.S.); (L.T.)
- Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go Francesco Vito 1, 00168 Roma, Italy
| | - Bianca Maria Scicchitano
- Sezione di Istologia ed Embriologia, Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, L.go Francesco Vito 1, 00168 Roma, Italy; (A.B.); (S.S.); (D.F.); (G.S.); (L.T.)
- Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go Francesco Vito 1, 00168 Roma, Italy
- Correspondence:
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10
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Li Y, Adeniji NT, Fan W, Kunimoto K, Török NJ. Non-alcoholic Fatty Liver Disease and Liver Fibrosis during Aging. Aging Dis 2022; 13:1239-1251. [PMID: 35855331 PMCID: PMC9286912 DOI: 10.14336/ad.2022.0318] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/18/2022] [Indexed: 01/10/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) and its progressive form non-alcoholic steatohepatitis (NASH) have emerged as the leading causes of chronic liver disease-related mortality. The prevalence of NAFLD/NASH is expected to increase given the epidemics of obesity and type 2 diabetes mellitus. Older patients are disproportionally affected by NASH and related complications such as progressive fibrosis, cirrhosis and hepatocellular carcinoma; however, they are often ineligible for liver transplantation due to their frailty and comorbidities, and effective medical treatments are still lacking. In this review we focused on pathways that are key to the aging process in the liver and perpetuate NAFLD/NASH, leading to fibrosis. In addition, we highlighted recent findings and cross-talks of normal and/or senescent liver cells, dysregulated nutrient sensing, proteostasis and mitochondrial dysfunction in the framework of changing metabolic milieu. Better understanding these pathways during preclinical and clinical studies will be essential to design novel and specific therapeutic strategies to treat NASH in the elderly.
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Affiliation(s)
| | | | | | | | - Natalie J. Török
- Correspondence should be addressed to: Dr. Natalie J. Török, Division of Gastroenterology and Hepatology, Stanford School of Medicine, Palo Alto, CA 94305, USA.
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11
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Huang Y, Shen Z, Huang C, Lin C, Tsai T. Cisd2 slows down liver aging and attenuates age-related metabolic dysfunction in male mice. Aging Cell 2021; 20:e13523. [PMID: 34811857 PMCID: PMC8672792 DOI: 10.1111/acel.13523] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/18/2021] [Accepted: 11/10/2021] [Indexed: 02/06/2023] Open
Abstract
The liver plays a pivotal role in mammalian aging. However, the mechanisms underlying liver aging remain unclear. Cisd2 is a pro‐longevity gene in mice. Cisd2 mediates lifespan and healthspan via regulation of calcium homeostasis and mitochondrial functioning. Intriguingly, the protein level of Cisd2 is significantly decreased by about 50% in the livers of old male mice. This down‐regulation of Cisd2 may result in the aging liver exhibiting non‐alcoholic fatty liver disease (NAFLD) phenotype. Here, we use Cisd2 transgenic mice to investigate whether maintaining Cisd2 protein at a persistently high level is able to slow down liver aging. Our study identifies four major discoveries. Firstly, that Cisd2 expression attenuates age‐related dysregulation of lipid metabolism and other pathological abnormalities. Secondly, revealed by RNA sequencing analysis, the livers of old male mice undergo extensive transcriptomic alterations, and these are associated with steatosis, hepatitis, fibrosis, and xenobiotic detoxification. Intriguingly, a youthful transcriptomic profile, like that of young 3‐month‐old mice, was found in old Cisd2 transgenic male mice at 26 months old. Thirdly, Cisd2 suppresses the age‐associated dysregulation of various transcription regulators (Nrf2, IL‐6, and Hnf4a), which keeps the transcriptional network in a normal pattern. Finally, a high level of Cisd2 protein protects the liver from oxidative stress, and this is associated with a reduction in mitochondrial DNA deletions. These findings demonstrate that Cisd2 is a promising target for the development of therapeutic agents that, by bringing about an effective enhancement of Cisd2 expression, will slow down liver aging.
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Affiliation(s)
- Yi‐Long Huang
- Department of Life Sciences and Institute of Genome Sciences National Yang Ming Chiao Tung University Taipei Taiwan
- Aging and Health Research Center National Yang Ming Chiao Tung University Taipei Taiwan
| | - Zhao‐Qing Shen
- Department of Life Sciences and Institute of Genome Sciences National Yang Ming Chiao Tung University Taipei Taiwan
| | - Chen‐Hua Huang
- Department of Life Sciences and Institute of Genome Sciences National Yang Ming Chiao Tung University Taipei Taiwan
| | - Chao‐Hsiung Lin
- Department of Life Sciences and Institute of Genome Sciences National Yang Ming Chiao Tung University Taipei Taiwan
- Aging and Health Research Center National Yang Ming Chiao Tung University Taipei Taiwan
| | - Ting‐Fen Tsai
- Department of Life Sciences and Institute of Genome Sciences National Yang Ming Chiao Tung University Taipei Taiwan
- Aging and Health Research Center National Yang Ming Chiao Tung University Taipei Taiwan
- Institute of Molecular and Genomic Medicine National Health Research Institutes Zhunan Taiwan
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12
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High Glycolytic Activity Enhances Stem Cell Reprogramming of Fahd1-KO Mouse Embryonic Fibroblasts. Cells 2021; 10:cells10082040. [PMID: 34440809 PMCID: PMC8392800 DOI: 10.3390/cells10082040] [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: 07/05/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondria play a key role in metabolic transitions involved in the reprogramming of somatic cells into induced pluripotent stem cells (iPSCs), but the underlying molecular mechanisms remain largely unexplored. To obtain new insight into the mechanisms of cellular reprogramming, we studied the role of FAH domain-containing protein 1 (FAHD1) in the reprogramming of murine embryonic fibroblasts (MEFs) into iPSCs and their subsequent differentiation into neuronal cells. MEFs from wild type (WT) and Fahd1-knock-out (KO) mice were reprogrammed into iPSCs and characterized for alterations in metabolic parameters and the expression of marker genes indicating mitochondrial biogenesis. Fahd1-KO MEFs showed a higher reprogramming efficiency accompanied by a significant increase in glycolytic activity as compared to WT. We also observed a strong increase of mitochondrial DNA copy number and expression of biogenesis marker genes in Fahd1-KO iPSCs relative to WT. Neuronal differentiation of iPSCs was accompanied by increased expression of mitochondrial biogenesis genes in both WT and Fahd1-KO neurons with higher expression in Fahd1-KO neurons. Together these observations establish a role of FAHD1 as a potential negative regulator of reprogramming and add additional insight into mechanisms by which FAHD1 modulates mitochondrial functions.
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13
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Huang YL, Shen ZQ, Huang CH, Teng YC, Lin CH, Tsai TF. Cisd2 Protects the Liver from Oxidative Stress and Ameliorates Western Diet-Induced Nonalcoholic Fatty Liver Disease. Antioxidants (Basel) 2021; 10:antiox10040559. [PMID: 33916843 PMCID: PMC8066189 DOI: 10.3390/antiox10040559] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/25/2021] [Accepted: 04/01/2021] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) and its more severe form, nonalcoholic steatohepatitis (NASH), are the most common chronic liver diseases worldwide. However, drugs to treat NAFLD and NASH are an unmet clinical need. This study sought to provide evidence that Cisd2 is a molecular target for the development of treatments targeting NAFLD and NASH. Several discoveries are pinpointed. The first is that Cisd2 dosage modulates the severity of Western diet-induced (WD-induced) NAFLD. Specifically, Cisd2 haploinsufficiency accelerates NAFLD development and exacerbates progression toward NASH. Conversely, an enhanced Cisd2 copy number attenuates liver pathogenesis. Secondly, when a WD is fed to mice, transcriptomic analysis reveals that the major alterations affecting biological processes are related to inflammation, lipid metabolism, and DNA replication/repair. Thirdly, among these differentially expressed genes, the most significant changes involve Nrf2-mediated oxidative stress, cholesterol biosynthesis, and fatty acid metabolism. Finally, increased Cisd2 expression protects the liver from oxidative stress and reduces the occurrence of mitochondrial DNA deletions. Taken together, our mouse model reveals that Cisd2 plays a crucial role in protecting the liver from WD-induced damages. The development of therapeutic agents that effectively enhance Cisd2 expression is one potential approach to the treatment of WD-induced fatty liver diseases.
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Affiliation(s)
- Yi-Long Huang
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; (Y.-L.H.); (Z.-Q.S.); (C.-H.H.); (Y.-C.T.)
- Aging and Health Research Center, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
| | - Zhao-Qing Shen
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; (Y.-L.H.); (Z.-Q.S.); (C.-H.H.); (Y.-C.T.)
| | - Chen-Hua Huang
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; (Y.-L.H.); (Z.-Q.S.); (C.-H.H.); (Y.-C.T.)
| | - Yuan-Chi Teng
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; (Y.-L.H.); (Z.-Q.S.); (C.-H.H.); (Y.-C.T.)
| | - Chao-Hsiung Lin
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; (Y.-L.H.); (Z.-Q.S.); (C.-H.H.); (Y.-C.T.)
- Aging and Health Research Center, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
- Correspondence: (C.-H.L.); (T.-F.T.); Tel.: +886-2-2826-67280 (C.-H.L.); +886-2-2826-67293 (T.-F.T.)
| | - Ting-Fen Tsai
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; (Y.-L.H.); (Z.-Q.S.); (C.-H.H.); (Y.-C.T.)
- Aging and Health Research Center, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan 350, Taiwan
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan 350, Taiwan
- Correspondence: (C.-H.L.); (T.-F.T.); Tel.: +886-2-2826-67280 (C.-H.L.); +886-2-2826-67293 (T.-F.T.)
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14
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Kimoloi S, Pla-Martín D, Oexner RR, Baris OR, Wiesner RJ. Author Response: K320E-Twinkleskm Mice Are Genetically Heterogeneous for Secondary mtDNA Deletions Impairing Comparison With Controls. Invest Ophthalmol Vis Sci 2021; 62:13. [PMID: 33427853 PMCID: PMC7804580 DOI: 10.1167/iovs.62.1.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Sammy Kimoloi
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany.,Department of Medical Laboratory Sciences, Masinde Muliro University of Science and Technology, Kakamega, Kenya
| | - David Pla-Martín
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Köln, Köln, Germany
| | - Rafael R Oexner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany
| | - Olivier R Baris
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany.,Equipe MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France
| | - Rudolf J Wiesner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Köln, Köln, Germany.,Center for Molecular Medicine Cologne, University of Köln, Köln, Germany. E-mail:
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15
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Swerdlow NS, Wilkins HM. Mitophagy and the Brain. Int J Mol Sci 2020; 21:ijms21249661. [PMID: 33352896 PMCID: PMC7765816 DOI: 10.3390/ijms21249661] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 02/06/2023] Open
Abstract
Stress mechanisms have long been associated with neuronal loss and neurodegenerative diseases. The origin of cell stress and neuronal loss likely stems from multiple pathways. These include (but are not limited to) bioenergetic failure, neuroinflammation, and loss of proteostasis. Cells have adapted compensatory mechanisms to overcome stress and circumvent death. One mechanism is mitophagy. Mitophagy is a form of macroautophagy, were mitochondria and their contents are ubiquitinated, engulfed, and removed through lysosome degradation. Recent studies have implicated mitophagy dysregulation in several neurodegenerative diseases and clinical trials are underway which target mitophagy pathways. Here we review mitophagy pathways, the role of mitophagy in neurodegeneration, potential therapeutics, and the need for further study.
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Affiliation(s)
- Natalie S. Swerdlow
- University of Kansas Alzheimer’s Disease Center, University of Kansas, Kansas City, KS 66160, USA;
| | - Heather M. Wilkins
- University of Kansas Alzheimer’s Disease Center, University of Kansas, Kansas City, KS 66160, USA;
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160, USA
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
- Correspondence:
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16
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Oexner RR, Pla-Martín D, Paß T, Wiesen MHJ, Zentis P, Schauss A, Baris OR, Kimoloi S, Wiesner RJ. Extraocular Muscle Reveals Selective Vulnerability of Type IIB Fibers to Respiratory Chain Defects Induced by Mitochondrial DNA Alterations. Invest Ophthalmol Vis Sci 2020; 61:14. [PMID: 33057669 PMCID: PMC7571275 DOI: 10.1167/iovs.61.12.14] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 09/15/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to gain insights on the pathogenesis of chronic progressive external ophthalmoplegia, thus we investigated the vulnerability of five extra ocular muscles (EOMs) fiber types to pathogenic mitochondrial DNA deletions in a mouse model expressing a mutated mitochondrial helicase TWINKLE. Methods Consecutive pairs of EOM sections were analyzed by cytochrome C oxidase (COX)/succinate dehydrogenase (SDH) assay and fiber type specific immunohistochemistry (type I, IIA, IIB, embryonic, and EOM-specific staining). Results The mean average of COX deficient fibers (COX-) in the recti muscles of mutant mice was 1.04 ± 0.52% at 12 months and increased with age (7.01 ± 1.53% at 24 months). A significant proportion of these COX- fibers were of the fast-twitch, glycolytic type IIB (> 50% and > 35% total COX- fibers at 12 and 24 months, respectively), whereas embryonic myosin heavy chain-expressing fibers were almost completely spared. Furthermore, the proportion of COX- fibers in the type IIB-rich retractor bulbi muscle was > 2-fold higher compared to the M. recti at both 12 (2.6 ± 0.78%) and 24 months (20.85 ± 2.69%). Collectively, these results demonstrate a selective vulnerability of type IIB fibers to mitochondrial DNA (mtDNA) deletions in EOMs and retractor bulbi muscle. We also show that EOMs of mutant mice display histopathological abnormalities, including altered fiber type composition, increased fibrosis, ragged red fibers, and infiltration of mononucleated nonmuscle cells. Conclusions Our results point to the existence of fiber type IIB-intrinsic factors and/or molecular mechanisms that predispose them to increased generation, clonal expansion, and detrimental effects of mtDNA deletions.
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MESH Headings
- Animals
- DNA, Mitochondrial/genetics
- Electron Transport Complex IV/metabolism
- Immunohistochemistry
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Mitochondria, Muscle/enzymology
- Mitochondria, Muscle/pathology
- Mitochondrial Diseases/enzymology
- Mitochondrial Diseases/genetics
- Mitochondrial Diseases/pathology
- Muscle Fibers, Fast-Twitch/enzymology
- Muscle Fibers, Fast-Twitch/pathology
- Muscle Fibers, Skeletal/enzymology
- Muscle Fibers, Skeletal/pathology
- Myosin Heavy Chains/metabolism
- Oculomotor Muscles/enzymology
- Oculomotor Muscles/pathology
- Ophthalmoplegia, Chronic Progressive External/etiology
- Real-Time Polymerase Chain Reaction
- Succinate Dehydrogenase/metabolism
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Affiliation(s)
- Rafael R. Oexner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany
| | - David Pla-Martín
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Köln, Köln, Germany
| | - Thomas Paß
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany
| | - Martin H. J. Wiesen
- Center of Pharmacology, Therapeutic Drug Monitoring Unit, Medical Faculty, University Hospital of Köln, Köln, Germany
| | - Peter Zentis
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Köln, Köln, Germany
| | - Astrid Schauss
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Köln, Köln, Germany
| | - Olivier R. Baris
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany
- Equipe MitoLab, UMR CNRS 6015, INSERM U1083, Institut MitoVasc, Université d'Angers, Angers, France
| | - Sammy Kimoloi
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany
- Department of Medical Laboratory Sciences, Masinde Muliro University of Science and Technology, Kakamega, Kenya
| | - Rudolf J. Wiesner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, Köln, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Köln, Köln, Germany
- Center for Molecular Medicine Cologne, University of Köln, Köln, Germany
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17
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Wanrooij PH, Tran P, Thompson LJ, Carvalho G, Sharma S, Kreisel K, Navarrete C, Feldberg AL, Watt DL, Nilsson AK, Engqvist MKM, Clausen AR, Chabes A. Elimination of rNMPs from mitochondrial DNA has no effect on its stability. Proc Natl Acad Sci U S A 2020; 117:14306-14313. [PMID: 32513727 PMCID: PMC7322039 DOI: 10.1073/pnas.1916851117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Ribonucleotides (rNMPs) incorporated in the nuclear genome are a well-established threat to genome stability and can result in DNA strand breaks when not removed in a timely manner. However, the presence of a certain level of rNMPs is tolerated in mitochondrial DNA (mtDNA) although aberrant mtDNA rNMP content has been identified in disease models. We investigated the effect of incorporated rNMPs on mtDNA stability over the mouse life span and found that the mtDNA rNMP content increased during early life. The rNMP content of mtDNA varied greatly across different tissues and was defined by the rNTP/dNTP ratio of the tissue. Accordingly, mtDNA rNMPs were nearly absent in SAMHD1-/- mice that have increased dNTP pools. The near absence of rNMPs did not, however, appreciably affect mtDNA copy number or the levels of mtDNA molecules with deletions or strand breaks in aged animals near the end of their life span. The physiological rNMP load therefore does not contribute to the progressive loss of mtDNA quality that occurs as mice age.
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Affiliation(s)
- Paulina H Wanrooij
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden;
| | - Phong Tran
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Liam J Thompson
- Institute of Biomedicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Gustavo Carvalho
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Sushma Sharma
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Katrin Kreisel
- Institute of Biomedicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Clara Navarrete
- Institute of Biomedicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Anna-Lena Feldberg
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Danielle L Watt
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Anna Karin Nilsson
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Martin K M Engqvist
- Institute of Biomedicine, University of Gothenburg, 405 30 Gothenburg, Sweden
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Anders R Clausen
- Institute of Biomedicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Andrei Chabes
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden;
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 901 87 Umeå, Sweden
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18
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Hargitai R, Roivainen P, Kis D, Luukkonen J, Sáfrány G, Seppälä J, Szatmári T, Virén T, Vuolukka K, Salomaa S, Lumniczky K. Mitochondrial DNA damage in the hair bulb: can it be used as a noninvasive biomarker of local exposure to low LET ionizing radiation? Int J Radiat Biol 2019; 96:491-501. [PMID: 31846382 DOI: 10.1080/09553002.2020.1704910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Purpose: Our aim was to evaluate whether mitochondrial DNA (mtDNA) damage in hair bulbs could be a suitable biomarker for the detection of local exposure to ionizing radiation.Materials and methods: Mouse hair was collected 4 and 24 hours, 3 and 10 days after single whole-body exposure to 0, 0.1, and 2 Gy radiation. Pubic hair (treated area) and scalp hair (control area) were collected from 13 prostate cancer patients before and after fractioned radiotherapy with an average total dose of 2.7 Gy to follicles after five fractions. Unspecified lesion frequency of mtDNA was analyzed with long PCR, large mtDNA deletion levels were tested with real-time PCR.Results: Unspecified lesion frequency of mtDNA significantly increased in mouse hair 24 hours after irradiation with 2 Gy, but variance among samples was high. No increase in lesion frequency could be detected after 0.1 Gy irradiation. In prostate cancer patients, there was no significant change in either the unspecified lesion frequency or in the proportion of 4934-bp deleted mtDNA in pubic hair after radiotherapy. The proportions of murine 3860-bp common deletion, human 4977-bp common deletion and 7455-bp deleted mtDNA were too low to be analyzed reliably.Conclusions: Our results suggest that the unspecified lesion frequency and proportion of large deletions of mtDNA in hair bulbs are not suitable biomarkers of exposure to ionizing radiation.
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Affiliation(s)
- Rita Hargitai
- Department of Radiation Medicine, Division of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - Päivi Roivainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Dávid Kis
- Department of Radiation Medicine, Division of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - Jukka Luukkonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Géza Sáfrány
- Department of Radiation Medicine, Division of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - Jan Seppälä
- Center of Oncology, Kuopio University Hospital, Kuopio, Finland
| | - Tünde Szatmári
- Department of Radiation Medicine, Division of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
| | - Tuomas Virén
- Center of Oncology, Kuopio University Hospital, Kuopio, Finland
| | | | - Sisko Salomaa
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Katalin Lumniczky
- Department of Radiation Medicine, Division of Radiobiology and Radiohygiene, National Public Health Centre, Budapest, Hungary
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19
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Fu A, Hou Y, Yu Z, Zhao Z, Liu Z. Healthy mitochondria inhibit the metastatic melanoma in lungs. Int J Biol Sci 2019; 15:2707-2718. [PMID: 31754341 PMCID: PMC6854369 DOI: 10.7150/ijbs.38104] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 08/21/2019] [Indexed: 01/10/2023] Open
Abstract
Tumor mitochondria alter their functions to reprogram cell metabolism and then allow tumor cells to rapidly proliferate in the hypoxic and acidic microenvironment. However, roles of normal mitochondria played in tumor progression are still unclear. Here we investigate the normal mitochondrial effect on abnormal metabolism of tumors, and to clarify why the mitochondria have to undergo functional changes in the tumor growth. The mitochondria isolated from healthy mouse livers were intravenously injected into melanoma model mice with lung metastasis, then the tumor growth, animal survival and associated metabolic changes were studied. The results reveal that the mitochondria significantly retard tumor growth and increase survival days of animals. The anti-tumor effect of the mitochondria is related to interfering the tumor cell metabolisms, such as reducing glycolysis and producing an oxidative intracellular environment, all of which are not suitable for tumor cell proliferation. In addition, the mitochondria increases cell apoptosis, necrosis, and mitophagy. These effects are more efficient with the mitochondria isolated from young mouse livers than those from aged mice. Our study not only provides a valuable approach to invest mitochondrial function associated with tumor growth but also offer new insight into tumor therapy through interfering the tumor cell metabolism by healthy mitochondria.
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Affiliation(s)
- Ailing Fu
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Yixue Hou
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Zhenyao Yu
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Zizhen Zhao
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Zesheng Liu
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
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20
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Lomaeva MG, Antipova VN, Bezlepkin VG, Gaziev AI. Mitochondrial DNA Deletion in Offspring of Female Mice Exposed to X-Rays. Biophysics (Nagoya-shi) 2019. [DOI: 10.1134/s0006350919040109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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21
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Sallmyr A, Tomkinson AE. Repair of DNA double-strand breaks by mammalian alternative end-joining pathways. J Biol Chem 2018. [PMID: 29530982 DOI: 10.1074/jbc.tm117.000375] [Citation(s) in RCA: 161] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alternative end-joining (a-EJ) pathways, which repair DNA double-strand breaks (DSBs), are initiated by end resection that generates 3' single strands. This reaction is shared, at least in part, with homologous recombination but distinguishes a-EJ from the major nonhomologous end-joining pathway. Although the a-EJ pathways make only a minor and poorly understood contribution to DSB repair in nonmalignant cells, there is growing interest in these pathways, as they generate genomic rearrangements that are hallmarks of cancer cells. Here, we review and discuss the current understanding of the mechanisms and regulation of a-EJ pathways, the role of a-EJ in human disease, and the potential utility of a-EJ as a therapeutic target in cancer.
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Affiliation(s)
- Annahita Sallmyr
- From the Departments of Internal Medicine and Molecular Genetics and Microbiology, University of New Mexico Comprehensive Cancer Center, University of New Mexico, Albuquerque, New Mexico 87131
| | - Alan E Tomkinson
- From the Departments of Internal Medicine and Molecular Genetics and Microbiology, University of New Mexico Comprehensive Cancer Center, University of New Mexico, Albuquerque, New Mexico 87131
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22
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Reactive oxygen species stress increases accumulation of tyrosyl-DNA phsosphodiesterase 1 within mitochondria. Sci Rep 2018. [PMID: 29523818 PMCID: PMC5844879 DOI: 10.1038/s41598-018-22547-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a nuclear and mitochondrial protein that in nuclei and in vitro repairs blocked 3' DNA termini such as 3' phosphotyrosine conjugates resulting from stalling of topoisomerase I-DNA intermediates. Its mutation also causes spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1). Because Tdp1 colocalizes with mitochondria following oxidative stress, we hypothesized that Tdp1 repairs mitochondrial DNA (mtDNA) and that mtDNA damage mediates entry of Tdp1 into the mitochondria. To test this, we used S. cerevisiae mutants, cultured mouse and human cells, and a Tdp1 knockout mouse. H2O2- and rotenone-induced cellular and intramitochondrial reactive oxygen species (ROS) activated oxidant-responsive kinases P38 and ERK1, and the translocation of Tdp1 from the nucleus to the mitochondria via the TIM/TOM complex. This translocation occurred independently of mtDNA. Within the mitochondria, Tdp1 interacted with Ligase III and reduced mtDNA mutations. Tdp1-deficient tissues had impaired mitochondrial respiration and decreased viability. These observations suggest that Tdp1 maintains mtDNA integrity and support the hypothesis that mitochondrial dysfunction contributes to the pathology of SCAN1.
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23
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Bielas J, Herbst A, Widjaja K, Hui J, Aiken JM, McKenzie D, Miller RA, Brooks SV, Wanagat J. Long term rapamycin treatment improves mitochondrial DNA quality in aging mice. Exp Gerontol 2018; 106:125-131. [PMID: 29486228 DOI: 10.1016/j.exger.2018.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/23/2018] [Accepted: 02/20/2018] [Indexed: 12/19/2022]
Abstract
Age-induced mitochondrial DNA deletion mutations may underlie cell loss and tissue aging. Rapamycin extends mouse lifespan and modulates mitochondrial quality control. We hypothesized that reduced deletion mutation abundance may contribute to rapamycin's life extension effects. To test this hypothesis, genetically heterogeneous male and female mice were treated with rapamycin, compounded in chow at 14 or 42 ppm, from 9 months to 22 months of age. Mice under a 40% dietary restriction were included as a control known to protect mtDNA quality. To determine if chronic rapamycin treatment affects mitochondrial DNA quality, we assayed mtDNA deletion frequency and electron transport chain deficient fiber abundances in mouse quadriceps muscle. At 42 ppm rapamycin, we observed a 57% decrease in deletion frequency, a 2.8-fold decrease in ETC deficient fibers, and a 3.4-fold increase in the number of mice without electron transport chain deficient fibers. We observed a similar trend with the 14 ppm dose. DR significantly decreased ETC deficient fiber abundances with a trend toward lower mtDNA deletion frequency. The effects of rapamycin treatment on mitochondrial DNA quality were greatest in females at the highest dose. Rapamycin treatment at 14 ppm did not affect muscle mass or function. Dietary restriction also reduced deletion frequency and ETC deficient fibers. These data support the concept that the lifespan extending effects of rapamycin treatment result from enhanced mitochondrial DNA quality.
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Affiliation(s)
- Jason Bielas
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Allen Herbst
- Department of Agricultural Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Kevin Widjaja
- Department of Medicine, Division of Geriatrics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Jessica Hui
- Department of Medicine, Division of Geriatrics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Judd M Aiken
- Department of Agricultural Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Debbie McKenzie
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Richard A Miller
- Department of Pathology and Geriatrics Center, University of Michigan, Ann Arbor, MI, USA
| | - Susan V Brooks
- Department of Molecular and Integrative Physiology, Geriatrics Center, University of Michigan, Ann Arbor, MI, USA
| | - Jonathan Wanagat
- Department of Medicine, Division of Geriatrics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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24
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Antipova VN, Lomaeva MG, Zyrina NV. Mitochondrial DNA deletions in tissues of mice after ionizing radiation exposure. Int J Radiat Biol 2018; 94:282-288. [DOI: 10.1080/09553002.2018.1419299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Valeriya N. Antipova
- Laboratory of Biophysics of Active Media, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Milena G. Lomaeva
- Laboratory of Radiation Molecular Biology, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Nadezhda V. Zyrina
- Laboratory of Crystallophysics and X-ray Research, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
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25
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Gomes MJ, Martinez PF, Pagan LU, Damatto RL, Cezar MDM, Lima ARR, Okoshi K, Okoshi MP. Skeletal muscle aging: influence of oxidative stress and physical exercise. Oncotarget 2017; 8:20428-20440. [PMID: 28099900 PMCID: PMC5386774 DOI: 10.18632/oncotarget.14670] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/09/2017] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle abnormalities are responsible for significant disability in the elderly. Sarcopenia is the main alteration occurring during senescence and a key public health issue as it predicts frailty, poor quality of life, and mortality. Several factors such as reduced physical activity, hormonal changes, insulin resistance, genetic susceptibility, appetite loss, and nutritional deficiencies are involved in the physiopathology of muscle changes. Sarcopenia is characterized by structural, biochemical, molecular and functional muscle changes. An imbalance between anabolic and catabolic intracellular signaling pathways and an increase in oxidative stress both play important roles in muscle abnormalities. Currently, despite the discovery of new targets and development of new drugs, nonpharmacological therapies such as physical exercise and nutritional support are considered the basis for prevention and treatment of age-associated muscle abnormalities. There has been an increase in information on signaling pathways beneficially modulated by exercise; nonetheless, studies are needed to establish the best type, intensity, and frequency of exercise to prevent or treat age-induced skeletal muscle alterations.
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Affiliation(s)
- Mariana Janini Gomes
- Botucatu Medical School, Internal Medicine Departament, Sao Paulo State University, UNESP, Botucatu, SP, Brazil
| | - Paula Felippe Martinez
- School of Physical Therapy, Federal University of Mato Grosso do Sul, Campo Grande, Brazil
| | - Luana Urbano Pagan
- Botucatu Medical School, Internal Medicine Departament, Sao Paulo State University, UNESP, Botucatu, SP, Brazil
| | - Ricardo Luiz Damatto
- Botucatu Medical School, Internal Medicine Departament, Sao Paulo State University, UNESP, Botucatu, SP, Brazil
| | | | - Aline Regina Ruiz Lima
- Botucatu Medical School, Internal Medicine Departament, Sao Paulo State University, UNESP, Botucatu, SP, Brazil
| | - Katashi Okoshi
- Botucatu Medical School, Internal Medicine Departament, Sao Paulo State University, UNESP, Botucatu, SP, Brazil
| | - Marina Politi Okoshi
- Botucatu Medical School, Internal Medicine Departament, Sao Paulo State University, UNESP, Botucatu, SP, Brazil
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26
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Cheng Z, Peng HL, Zhang R, Fu XM, Zhang GS. Rejuvenation of Cardiac Tissue Developed from Reprogrammed Aged Somatic Cells. Rejuvenation Res 2017; 20:389-400. [PMID: 28478705 DOI: 10.1089/rej.2017.1930] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Induced pluripotent stem cells (iPSCs) derived via somatic cell reprogramming have been reported to reset aged somatic cells to a more youthful state, characterized by elongated telomeres, a rearranged mitochondrial network, reduced oxidative stress, and restored pluripotency. However, it is still unclear whether the reprogrammed aged somatic cells can function normally as embryonic stem cells (ESCs) during development and be rejuvenated. In the current study, we applied the aggregation technique to investigate whether iPSCs derived from aged somatic cells could develop normally and be rejuvenated. iPSCs derived from bone marrow myeloid cells of 2-month-old (2 M) and 18-month-old (18 M) C57BL/6-Tg (CAG-EGFP)1Osb/J mice were aggregated with embryos derived from wild-type ICR mice to produce chimeras (referred to as 2 M CA and 18 M CA, respectively). Our observations focused on comparing the ability of the iPSCs derived from 18 M and 2 M bone marrow cells to develop rejuvenated cardiac tissue (the heart is the most vital organ during aging). The results showed an absence of p16 and p53 upregulation, telomere length shortening, and mitochondrial gene expression and deletion in 18 M CA, whereas slight changes in mitochondrial ultrastructure, cytochrome C oxidase activity, ATP production, and reactive oxygen species production were observed in CA cardiac tissues. The data implied that all of the aging characteristics observed in the newborn cardiac tissue of 18 M CA were comparable with those of 2 M CA newborn cardiac tissue. This study provides the first direct evidence of the aging-related characteristics of cardiac tissue developed from aged iPSCs, and our observations demonstrate that partial rejuvenation can be achieved by reprogramming aged somatic cells to a pluripotent state.
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Affiliation(s)
- Zhao Cheng
- 1 Department of Hematology, Institute of Molecular Hematology, The Second Xiang-ya Hospital, Central South University , Changsha, People's Republic of China
| | - Hong-Ling Peng
- 1 Department of Hematology, Institute of Molecular Hematology, The Second Xiang-ya Hospital, Central South University , Changsha, People's Republic of China
| | - Rong Zhang
- 2 Division of Cancer Immunotherapy, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center , Kashiwanoha, Kashiwa, Japan
| | - Xian-Ming Fu
- 3 Department of Cardiac Surgery, The Second Xiang-ya Hospital, Central South University , Changsha, People's Republic of China
| | - Guang-Sen Zhang
- 1 Department of Hematology, Institute of Molecular Hematology, The Second Xiang-ya Hospital, Central South University , Changsha, People's Republic of China
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27
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Abstract
Mitochondrial DNA (mtDNA) lacks the protection provided by the nucleosomes in the nuclear DNA and does not have a DNA repair mechanism, making it highly susceptible to damage, which can lead to mtDNA depletion. mtDNA depletion compromises the efficient function of cells and tissues and thus impacts negatively on health. Here, we describe a brief and easy protocol to quantify mtDNA copy number by determining the mtDNA/nDNA ratio. The procedure has been validated using a cohort of young and aged mice. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Pedro M Quiros
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Aashima Goyal
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Pooja Jha
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Johan Auwerx
- Laboratory for Integrative and Systems Physiology, École Polytechnique Federale de Lausanne, Lausanne, Switzerland
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28
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Valente WJ, Ericson NG, Long AS, White PA, Marchetti F, Bielas JH. Mitochondrial DNA exhibits resistance to induced point and deletion mutations. Nucleic Acids Res 2016; 44:8513-8524. [PMID: 27550180 PMCID: PMC5062989 DOI: 10.1093/nar/gkw716] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 08/04/2016] [Indexed: 12/17/2022] Open
Abstract
The accumulation of somatic mitochondrial DNA (mtDNA) mutations contributes to the pathogenesis of human disease. Currently, mitochondrial mutations are largely considered results of inaccurate processing of its heavily damaged genome. However, mainly from a lack of methods to monitor mtDNA mutations with sufficient sensitivity and accuracy, a link between mtDNA damage and mutation has not been established. To test the hypothesis that mtDNA-damaging agents induce mtDNA mutations, we exposed MutaTMMouse mice to benzo[a]pyrene (B[a]P) or N-ethyl-N-nitrosourea (ENU), daily for 28 consecutive days, and quantified mtDNA point and deletion mutations in bone marrow and liver using our newly developed Digital Random Mutation Capture (dRMC) and Digital Deletion Detection (3D) assays. Surprisingly, our results demonstrate mutagen treatment did not increase mitochondrial point or deletion mutation frequencies, despite evidence both compounds increase nuclear DNA mutations and demonstrated B[a]P adduct formation in mtDNA. These findings contradict models of mtDNA mutagenesis that assert the elevated rate of mtDNA mutation stems from damage sensitivity and abridged repair capacity. Rather, our results demonstrate induced mtDNA damage does not readily convert into mutation. These findings suggest robust mitochondrial damage responses repress induced mutations after mutagen exposure.
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Affiliation(s)
- William J Valente
- Translational Research Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA Medical Scientist Training Program, University of Washington School of Medicine, Seattle, WA 98195, USA Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Nolan G Ericson
- Translational Research Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Alexandra S Long
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Paul A White
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Jason H Bielas
- Translational Research Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA Department of Pathology, University of Washington, Seattle, WA 98195, USA Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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29
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Tadi SK, Sebastian R, Dahal S, Babu RK, Choudhary B, Raghavan SC. Microhomology-mediated end joining is the principal mediator of double-strand break repair during mitochondrial DNA lesions. Mol Biol Cell 2015; 27:223-35. [PMID: 26609070 PMCID: PMC4713127 DOI: 10.1091/mbc.e15-05-0260] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 11/18/2015] [Indexed: 12/13/2022] Open
Abstract
Repair of double-strand breaks in mammalian mitochondria depends on microhomology-mediated end joining (MMEJ). Classical NHEJ is not detectable in mitochondria. DNA ligase III, but not ligase IV or ligase I, is involved in mitochondrial MMEJ. The protein machinery involved in miitochondrial MMEJ includes CtIP, FEN1, ligase III, MRE11, and PARP1. Mitochondrial DNA (mtDNA) deletions are associated with various mitochondrial disorders. The deletions identified in humans are flanked by short, directly repeated mitochondrial DNA sequences; however, the mechanism of such DNA rearrangements has yet to be elucidated. In contrast to nuclear DNA (nDNA), mtDNA is more exposed to oxidative damage, which may result in double-strand breaks (DSBs). Although DSB repair in nDNA is well studied, repair mechanisms in mitochondria are not characterized. In the present study, we investigate the mechanisms of DSB repair in mitochondria using in vitro and ex vivo assays. Whereas classical NHEJ (C-NHEJ) is undetectable, microhomology-mediated alternative NHEJ efficiently repairs DSBs in mitochondria. Of interest, robust microhomology-mediated end joining (MMEJ) was observed with DNA substrates bearing 5-, 8-, 10-, 13-, 16-, 19-, and 22-nt microhomology. Furthermore, MMEJ efficiency was enhanced with an increase in the length of homology. Western blotting, immunoprecipitation, and protein inhibition assays suggest the involvement of CtIP, FEN1, MRE11, and PARP1 in mitochondrial MMEJ. Knockdown studies, in conjunction with other experiments, demonstrated that DNA ligase III, but not ligase IV or ligase I, is primarily responsible for the final sealing of DSBs during mitochondrial MMEJ. These observations highlight the central role of MMEJ in maintenance of mammalian mitochondrial genome integrity and is likely relevant for deletions observed in many human mitochondrial disorders.
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Affiliation(s)
- Satish Kumar Tadi
- Department of Biochemistry, Indian Institute of Science, Bangalore 560 012, India
| | - Robin Sebastian
- Department of Biochemistry, Indian Institute of Science, Bangalore 560 012, India
| | - Sumedha Dahal
- Department of Biochemistry, Indian Institute of Science, Bangalore 560 012, India
| | - Ravi K Babu
- Department of Biochemistry, Indian Institute of Science, Bangalore 560 012, India
| | - Bibha Choudhary
- Institute of Bioinformatics and Applied Biotechnology, Bangalore 560 100, India
| | - Sathees C Raghavan
- Department of Biochemistry, Indian Institute of Science, Bangalore 560 012, India
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30
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Ueda S, Ozawa S, Mori K, Asanuma K, Yanagita M, Uchida S, Nakagawa T. ENOS deficiency causes podocyte injury with mitochondrial abnormality. Free Radic Biol Med 2015; 87:181-92. [PMID: 26119782 DOI: 10.1016/j.freeradbiomed.2015.06.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 05/20/2015] [Accepted: 06/08/2015] [Indexed: 10/23/2022]
Abstract
The contribution of endothelial nitric oxide synthase (eNOS) to podocyte integrity remains unclear. This study therefore examined podocytes and mitochondrial abnormalities in eNOS deficient mice. Absence of eNOS caused glomerular hypertrophy, along with occasional glomerular sclerosis and mesangiolysis. While many glomeruli did not have such advanced lesions, ultrastructural analysis showed cellular hypertrophy, vacuolization, lysosomal enlargement, and microvillus formation in podocytes of eNOS knockout (KO) mice. Increased oxidative stress was associated with mitochondrial abnormalities, including an increase in number, coupled with a reduction in size, of mitochondria in podocytes of eNOS-KO mice. While the levels of expression of several mitochondrial proteins were not altered, the d-17 mutation in mitochondrial DNA was significantly associated with the eNOS deficiency. Renal ATP level in the renal cortex and mitochondrial respiration in the primary podocytes were significantly lower in eNOS-KO mice, suggesting that renal mitochondria may be functionally impaired. Podocytes cultured with endothelial conditioned medium lacking NO consistently showed a greater degree of mitochondrial fragmentation and an increase in mitochondrial oxidative stress, with these mitochondrial alterations rescued by an NO donor. In conclusion, eNOS may be necessary to maintain podocyte integrity, especially mitochondrial function.
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Affiliation(s)
- Shuko Ueda
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan; Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Shota Ozawa
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan; Pharmacology Research Laboratories II, Mitsubishi Tanabe Pharma Corporation, Saitama, Japan
| | - Kiyoshi Mori
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan
| | - Katsuhiko Asanuma
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan
| | - Motoko Yanagita
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan; Department of Nephrology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shunya Uchida
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Takahiko Nakagawa
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan.
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31
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Bowen TS, Schuler G, Adams V. Skeletal muscle wasting in cachexia and sarcopenia: molecular pathophysiology and impact of exercise training. J Cachexia Sarcopenia Muscle 2015; 6:197-207. [PMID: 26401465 PMCID: PMC4575550 DOI: 10.1002/jcsm.12043] [Citation(s) in RCA: 269] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 03/23/2015] [Accepted: 04/23/2015] [Indexed: 12/11/2022] Open
Abstract
Skeletal muscle provides a fundamental basis for human function, enabling locomotion and respiration. Transmission of external stimuli to intracellular effector proteins via signalling pathways is a highly regulated and controlled process that determines muscle mass by balancing protein synthesis and protein degradation. An impaired balance between protein synthesis and breakdown leads to the development of specific myopathies. Sarcopenia and cachexia represent two distinct muscle wasting diseases characterized by inflammation and oxidative stress, where specific regulating molecules associated with wasting are either activated (e.g. members of the ubiquitin-proteasome system and myostatin) or repressed (e.g. insulin-like growth factor 1 and PGC-1α). At present, no therapeutic interventions are established to successfully treat muscle wasting in sarcopenia and cachexia. Exercise training, however, represents an intervention that can attenuate or even reverse the process of muscle wasting, by exerting anti-inflammatory and anti-oxidative effects that are able to attenuate signalling pathways associated with protein degradation and activate molecules associated with protein synthesis. This review will therefore discuss the molecular mechanisms associated with the pathology of muscle wasting in both sarcopenia and cachexia, as well as highlighting the intracellular effects of exercise training in attenuating the debilitating loss of muscle mass in these specific conditions.
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Affiliation(s)
- T Scott Bowen
- Department of Cardiology, University Leipzig - Heart Center Leipzig Leipzig, Germany
| | - Gerhard Schuler
- Department of Cardiology, University Leipzig - Heart Center Leipzig Leipzig, Germany
| | - Volker Adams
- Department of Cardiology, University Leipzig - Heart Center Leipzig Leipzig, Germany
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32
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Mosaic Deficiency in Mitochondrial Oxidative Metabolism Promotes Cardiac Arrhythmia during Aging. Cell Metab 2015; 21:667-77. [PMID: 25955204 DOI: 10.1016/j.cmet.2015.04.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 02/04/2015] [Accepted: 03/31/2015] [Indexed: 11/21/2022]
Abstract
Aging is a progressive decline of body function, during which many tissues accumulate few cells with high levels of deleted mitochondrial DNA (mtDNA), leading to a defect of mitochondrial functions. Whether this mosaic mitochondrial deficiency contributes to organ dysfunction is unknown. To investigate this, we generated mice with an accelerated accumulation of mtDNA deletions in the myocardium, by expressing a dominant-negative mutant mitochondrial helicase. These animals accumulated few randomly distributed cardiomyocytes with compromised mitochondrial function, which led to spontaneous ventricular premature contractions and AV blocks at 18 months. These symptoms were not caused by a general mitochondrial dysfunction in the entire myocardium, and were not observed in mice at 12 months with significantly lower numbers of dysfunctional cells. Therefore, our results suggest that the disposition to arrhythmia typically found in the aged human heart might be due to the random accumulation of mtDNA deletions and the subsequent mosaic respiratory chain deficiency.
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33
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Baig UI, Bhadbhade BJ, Watve MG. Evolution of aging and death: what insights bacteria can provide. QUARTERLY REVIEW OF BIOLOGY 2014; 89:209-23. [PMID: 25195317 DOI: 10.1086/677572] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Several unresolved issues, paradoxes, and information voids characterize the field of evolution of aging. The recent discovery of aging-like phenomenon in Escherichia coli, marked by asymmetric segregation of damaged components, particularly protein aggregates, has created a number of new possibilities that remain underexplored. Bacterial systems can potentially throw light on issues such as: whether evolution of aging and evolution of death are different phenomena; whether aging is inevitable for life or is an evolved strategy; whether there could be selection for aging or aging is a pleiotropic effect of some other selection; what are the possible mechanisms of antagonistic pleiotropy, if any; and whether there are mechanisms of aging that are conserved throughout the hierarchy of life. Bacterial aging itself is underexplored and least understood as of now, but even scratching the surface appears to reveal things that may compel us to revise some of the classical concepts about evolution of aging. This warrants more focused and innovative inquiry into aging-like processes in bacteria.
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34
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Kalifa L, Gewandter JS, Staversky RJ, Sia EA, Brookes PS, O'Reilly MA. DNA double-strand breaks activate ATM independent of mitochondrial dysfunction in A549 cells. Free Radic Biol Med 2014; 75:30-9. [PMID: 25048973 PMCID: PMC4171189 DOI: 10.1016/j.freeradbiomed.2014.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 10/25/2022]
Abstract
Excessive nuclear or mitochondrial DNA damage can lead to mitochondrial dysfunction, decreased energy production, and increased generation of reactive oxygen species (ROS). Although numerous cell signaling pathways are activated when cells are injured, the ataxia telangiectasia mutant (ATM) protein has emerged as a major regulator of the response to both mitochondrial dysfunction and nuclear DNA double-strand breaks (DSBs). Because mitochondrial dysfunction is often a response to excessive DNA damage, it has been difficult to determine whether nuclear and/or mitochondrial DNA DSBs activate ATM independent of mitochondrial dysfunction. In this study, mitochondrial and nuclear DNA DSBs were generated in the A549 human lung adenocarcinoma cell line by infecting with retroviruses expressing the restriction endonuclease PstI fused to a mitochondrial targeting sequence (MTS) or nuclear localization sequence (NLS) and a hemagglutinin antigen epitope tag (HA). Expression of MTS-PstI-HA or NLS-PstI-HA activated the DNA damage response defined by phosphorylation of ATM, the tumor suppressor protein p53 (TP53), KRAB-associated protein (KAP)-1, and structural maintenance of chromosomes (SMC)-1. Phosphorylated ATM and SMC1 were detected in nuclear fractions, whereas phosphorylated TP53 and KAP1 were detected in both mitochondrial and nuclear fractions. PstI also enhanced expression of the cyclin-dependent kinase inhibitor p21 and inhibited cell growth. This response to DNA damage occurred in the absence of detectable mitochondrial dysfunction and excess production of ROS. These findings reveal that DNA DSBs are sufficient to activate ATM independent of mitochondrial dysfunction and suggest that the activated form of ATM and some of its substrates are restricted to the nuclear compartment, regardless of the site of DNA damage.
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Affiliation(s)
- Lidza Kalifa
- Department of Environmental Medicine, The University of Rochester, Rochester, NY 14642, USA
| | - Jennifer S Gewandter
- Department of Anesthesiology, The University of Rochester, Rochester, NY 14642, USA
| | - Rhonda J Staversky
- Department of Pediatrics, The University of Rochester, Rochester, NY 14642, USA
| | - Elaine A Sia
- Department of Biology, The University of Rochester, Rochester, NY 14642, USA
| | - Paul S Brookes
- Department of Anesthesiology, The University of Rochester, Rochester, NY 14642, USA
| | - Michael A O'Reilly
- Department of Pediatrics, The University of Rochester, Rochester, NY 14642, USA.
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Garcia-Diaz B, Garone C, Barca E, Mojahed H, Gutierrez P, Pizzorno G, Tanji K, Arias-Mendoza F, Quinzii CM, Hirano M. Deoxynucleoside stress exacerbates the phenotype of a mouse model of mitochondrial neurogastrointestinal encephalopathy. ACTA ACUST UNITED AC 2014; 137:1337-49. [PMID: 24727567 PMCID: PMC3999724 DOI: 10.1093/brain/awu068] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Balanced pools of deoxyribonucleoside triphosphate precursors are required for DNA replication, and alterations of this balance are relevant to human mitochondrial diseases including mitochondrial neurogastrointestinal encephalopathy. In this disease, autosomal recessive TYMP mutations cause severe reductions of thymidine phosphorylase activity; marked elevations of the pyrimidine nucleosides thymidine and deoxyuridine in plasma and tissues, and somatic multiple deletions, depletion and site-specific point mutations of mitochondrial DNA. Thymidine phosphorylase and uridine phosphorylase double knockout mice recapitulated several features of these patients including thymidine phosphorylase activity deficiency, elevated thymidine and deoxyuridine in tissues, mitochondrial DNA depletion, respiratory chain defects and white matter changes. However, in contrast to patients with this disease, mutant mice showed mitochondrial alterations only in the brain. To test the hypothesis that elevated levels of nucleotides cause unbalanced deoxyribonucleoside triphosphate pools and, in turn, pathogenic mitochondrial DNA instability, we have stressed double knockout mice with exogenous thymidine and deoxyuridine, and assessed clinical, neuroradiological, histological, molecular, and biochemical consequences. Mutant mice treated with exogenous thymidine and deoxyuridine showed reduced survival, body weight, and muscle strength, relative to untreated animals. Moreover, in treated mutants, leukoencephalopathy, a hallmark of the disease, was enhanced and the small intestine showed a reduction of smooth muscle cells and increased fibrosis. Levels of mitochondrial DNA were depleted not only in the brain but also in the small intestine, and deoxyribonucleoside triphosphate imbalance was observed in the brain. The relative proportion, rather than the absolute amount of deoxyribonucleoside triphosphate, was critical for mitochondrial DNA maintenance. Thus, our results demonstrate that stress of exogenous pyrimidine nucleosides enhances the mitochondrial phenotype of our knockout mice. Our mouse studies provide insights into the pathogenic role of thymidine and deoxyuridine imbalance in mitochondrial neurogastrointestinal encephalopathy and an excellent model to study new therapeutic approaches.
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Affiliation(s)
- Beatriz Garcia-Diaz
- 1 Department of Neurology, Columbia University Medical Centre, New York, NY, 10032, USA
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Affiliation(s)
- J. William O. Ballard
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney New South Wales 2052 Australia
| | - Nicolas Pichaud
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney New South Wales 2052 Australia
- Laboratoire de Biologie Intégrative; Département de Biologie, Chimie et Géographie; Université du Québec à Rimouski; Rimouski Quebec Canada
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Dugan LL, You YH, Ali SS, Diamond-Stanic M, Miyamoto S, DeCleves AE, Andreyev A, Quach T, Ly S, Shekhtman G, Nguyen W, Chepetan A, Le TP, Wang L, Xu M, Paik KP, Fogo A, Viollet B, Murphy A, Brosius F, Naviaux RK, Sharma K. AMPK dysregulation promotes diabetes-related reduction of superoxide and mitochondrial function. J Clin Invest 2013; 123:4888-99. [PMID: 24135141 DOI: 10.1172/jci66218] [Citation(s) in RCA: 354] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 08/08/2013] [Indexed: 12/27/2022] Open
Abstract
Diabetic microvascular complications have been considered to be mediated by a glucose-driven increase in mitochondrial superoxide anion production. Here, we report that superoxide production was reduced in the kidneys of a steptozotocin-induced mouse model of type 1 diabetes, as assessed by in vivo real-time transcutaneous fluorescence, confocal microscopy, and electron paramagnetic resonance analysis. Reduction of mitochondrial biogenesis and phosphorylation of pyruvate dehydrogenase (PDH) were observed in kidneys from diabetic mice. These observations were consistent with an overall reduction of mitochondrial glucose oxidation. Activity of AMPK, the major energy-sensing enzyme, was reduced in kidneys from both diabetic mice and humans. Mitochondrial biogenesis, PDH activity, and mitochondrial complex activity were rescued by treatment with the AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR). AICAR treatment induced superoxide production and was linked with glomerular matrix and albuminuria reduction in the diabetic kidney. Furthermore, diabetic heterozygous superoxide dismutase 2 (Sod2(+/-)) mice had no evidence of increased renal disease, and Ampka2(-/-) mice had increased albuminuria that was not reduced with AICAR treatment. Reduction of mitochondrial superoxide production with rotenone was sufficient to reduce AMPK phosphorylation in mouse kidneys. Taken together, these results demonstrate that diabetic kidneys have reduced superoxide and mitochondrial biogenesis and activation of AMPK enhances superoxide production and mitochondrial function while reducing disease activity.
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Neuhaus JFG, Baris OR, Hess S, Moser N, Schröder H, Chinta SJ, Andersen JK, Kloppenburg P, Wiesner RJ. Catecholamine metabolism drives generation of mitochondrial DNA deletions in dopaminergic neurons. ACTA ACUST UNITED AC 2013; 137:354-65. [PMID: 24163249 DOI: 10.1093/brain/awt291] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Accumulation of mitochondrial DNA deletions is observed especially in dopaminergic neurons of the substantia nigra during ageing and even more in Parkinson's disease. The resulting mitochondrial dysfunction is suspected to play an important role in neurodegeneration. However, the molecular mechanisms involved in the preferential generation of mitochondrial DNA deletions in dopaminergic neurons are still unknown. To study this phenomenon, we developed novel polymerase chain reaction strategies to detect distinct mitochondrial DNA deletions and monitor their accumulation patterns. Applying these approaches in in vitro and in vivo models, we show that catecholamine metabolism drives the generation and accumulation of these mitochondrial DNA mutations. As in humans, age-related accumulation of mitochondrial DNA deletions is most prominent in dopaminergic areas of mouse brain and even higher in the catecholaminergic adrenal medulla. Dopamine treatment of terminally differentiated neuroblastoma cells, as well as stimulation of dopamine turnover in mice over-expressing monoamine oxidase B both induce multiple mitochondrial DNA deletions. Our results thus identify catecholamine metabolism as the driving force behind mitochondrial DNA deletions, probably being an important factor in the ageing-associated degeneration of dopaminergic neurons.
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Affiliation(s)
- Johannes F G Neuhaus
- 1 Centre for Physiology and Pathophysiology, Institute of Vegetative Physiology, Medical Faculty, University of Köln, Germany
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Kazachkova N, Ramos A, Santos C, Lima M. Mitochondrial DNA damage patterns and aging: revising the evidences for humans and mice. Aging Dis 2013; 4:337-50. [PMID: 24307967 DOI: 10.14336/ad.2013.0400337] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 01/07/2023] Open
Abstract
A significant body of work, accumulated over the years, strongly suggests that damage in mitochondrial DNA (mtDNA) contributes to aging in humans. Contradictory results, however, are reported in the literature, with some studies failing to provide support to this hypothesis. With the purpose of further understanding the aging process, several models, among which mouse models, have been frequently used. Although important affinities are recognized between humans and mice, differences on what concerns physiological properties, disease pathogenesis as well as life-history exist between the two; the extent to which such differences limit the translation, from mice to humans, of insights on the association between mtDNA damage and aging remains to be established. In this paper we revise the studies that analyze the association between patterns of mtDNA damage and aging, investigating putative alterations in mtDNA copy number as well as accumulation of deletions and of point mutations. Reports from the literature do not allow the establishment of a clear association between mtDNA copy number and age, either in humans or in mice. Further analysis, using a wide spectrum of tissues and a high number of individuals would be necessary to elucidate this pattern. Likewise humans, mice demonstrated a clear pattern of age-dependent and tissue-specific accumulation of mtDNA deletions. Deletions increase with age, and the highest amount of deletions has been observed in brain tissues both in humans and mice. On the other hand, mtDNA point mutations accumulation has been clearly associated with age in humans, but not in mice. Although further studies, using the same methodologies and targeting a larger number of samples would be mandatory to draw definitive conclusions, the revision of the available data raises concerns on the ability of mouse models to mimic the mtDNA damage patterns of humans, a fact with implications not only for the study of the aging process, but also for investigations of other processes in which mtDNA dysfunction is a hallmark, such as neurodegeneration.
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Affiliation(s)
- Nadiya Kazachkova
- Centre of Research in Natural Resources (CIRN), Department of Biology, University of the Azores, Ponta Delgada, Portugal ; Institute for Molecular and Cell Biology (IBMC), University of Porto, Porto, Portugal
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Zhang SB, Maguire D, Zhang M, Zhang Z, Zhang A, Yin L, Zhang L, Huang L, Vidyasagar S, Swarts S, Okunieff P. The murine common deletion: mitochondrial DNA 3,860-bp deletion after irradiation. Radiat Res 2013; 180:407-13. [PMID: 24059680 DOI: 10.1667/rr3373.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This study demonstrates that mice, similar to humans, have a common mitochondrial DNA deletion (3,860 bp) that encodes 5 transfer RNA genes and 5 polypeptide genes that is related to aging, tissue type and radiotoxicity. Our research indicates that the deletion ratio in the liver was significantly higher than in the brain and gut tissues of 8-month-old mice, as compared to 8-week-old mice. Our results also demonstrate that tissue type, oxidative metabolic capacity and radiosensitivity influence the 3,860-bp deletion level. Therefore, this 3,860-bp deletion content may serve as a biomarker of aging and oxidative damage in mice.
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Affiliation(s)
- Steven B Zhang
- Department of Radiation Oncology, University of Florida, Cancer and Genetics Research Complex, Gainesville, Florida 32610
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Kowald A, Kirkwood TBL. Mitochondrial mutations and aging: random drift is insufficient to explain the accumulation of mitochondrial deletion mutants in short-lived animals. Aging Cell 2013; 12:728-31. [PMID: 23742009 DOI: 10.1111/acel.12098] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2013] [Indexed: 10/26/2022] Open
Abstract
Mitochondrial DNA deletions accumulate over the life course in post-mitotic cells of many species and may contribute to aging. Often a single mutant expands clonally and finally replaces the wild-type population of a whole cell. One proposal to explain the driving force behind this accumulation states that random drift alone, without any selection advantage, is sufficient to explain the clonal accumulation of a single mutant. Existing mathematical models show that such a process might indeed work for humans. However, to be a general explanation for the clonal accumulation of mtDNA mutants, it is important to know whether random drift could also explain the accumulation process in short-lived species like rodents. To clarify this issue, we modelled this process mathematically and performed extensive computer simulations to study how different mutation rates affect accumulation time and the resulting degree of heteroplasmy. We show that random drift works for lifespans of around 100 years, but for short-lived animals, the resulting degree of heteroplasmy is incompatible with experimental observations.
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Affiliation(s)
- Axel Kowald
- Centre for Integrated Systems Biology of Ageing and Nutrition Institute for Ageing and Health Newcastle University Newcastle upon Tyne NE4 5PLUK
| | - Thomas B. L. Kirkwood
- Centre for Integrated Systems Biology of Ageing and Nutrition Institute for Ageing and Health Newcastle University Newcastle upon Tyne NE4 5PLUK
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Aoyama H, Kuroiwa T, Nakamura S. Chronological transition of mitochondrial morphology in Chlamydomonas reinhardtii (Chlorophyceae) poststationary phase growth(1). JOURNAL OF PHYCOLOGY 2013; 49:340-348. [PMID: 27008520 DOI: 10.1111/jpy.12040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 10/18/2012] [Indexed: 06/05/2023]
Abstract
In Chlamydomonas reinhardtii P. A. Dangeard, mitochondrial morphology has been observed during asexual cell division cycle, gamete and zygote formation, zygote maturation, and meiotic stages. However, the chronological transition of mitochondrial morphology after the stationary phase of vegetative growth, defined as the poststationary phase, remains unknown. Here, we examined the mitochondrial morphology in cells cultured for 4 months on agar plates to study mitochondrial dynamics in the poststationary phase. Fluorescence microscopy showed that the intricate thread-like structure of mitochondria gradually changed into a granular structure via fragmentation after the stationary phase in cultures of about 1 week of age. The number of mitochondrial nucleoids decreased from about 30 per cell at 1 week to about five per cell after 4 months of culture. The mitochondrial oxygen consumption decreased exponentially, but the mitochondria retained their membrane potential. The total quantity of mitochondrial DNA (mtDNA) of cells at 4 months decreased to 20% of that at 1 week. However, the mitochondrial genomic DNA length was unchanged, as intermediate lengths were not detected. In cells in which the total mtDNA amount was reduced artificially to 16% after treatment with 5-fluoro-2-deoxyuridine (FdUrd) for 1 week, the mitochondria remained as thread-like structures. The oxygen consumption rate of these cells corresponded to that of untreated cells at 1 week of culture. This suggests that a decrease in mtDNA does not directly induce the fragmentation of mitochondria. The results suggest that during the late poststationary phase, mitochondria converge to a minimum unit of a granular structure with a mitochondrial nucleoid.
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Affiliation(s)
- Hiroaki Aoyama
- Center of Molecular Biosciences, Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan
- Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan
| | - Tsuneyoshi Kuroiwa
- Initiative Research Unit, College of Science, Rikkyo University, Nishi-Ikebukuro, Tokyo, 171-8501, Japan
| | - Soichi Nakamura
- Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan
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Torrell H, Montaña E, Abasolo N, Roig B, Gaviria AM, Vilella E, Martorell L. Mitochondrial DNA (mtDNA) in brain samples from patients with major psychiatric disorders: gene expression profiles, mtDNA content and presence of the mtDNA common deletion. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:213-23. [PMID: 23355257 DOI: 10.1002/ajmg.b.32134] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 01/03/2013] [Indexed: 01/26/2023]
Abstract
Several lines of evidence support a mitochondrial dysfunction in major psychiatric disorders. The objective of this study was to determine whether mitochondrial DNA (mtDNA) expression or content are implicated in the mitochondrial dysfunction observed in schizophrenia (SCH), bipolar disorder (BD), and major depressive disorder (MDD). MtDNA gene expression and mtDNA content (including the MT-ND4 deletion) were measured by RT-qPCR and qPCR, respectively. Post-mortem brain tissue from 60 subjects, divided evenly into four diagnostic groups (SCH, BD, MDD, and control (C)), was analyzed. MT-ND1 gene expression was significantly increased in the BD group compared with the C group. MDD and SCH patients showed a similar pattern of mtDNA expression, which was different from that in BD patients. Similarly, a larger number of MDD and SCH patients tended to have the MT-ND4 gene deleted compared with BD and C subjects. However, no other significant differences were observed in mtDNA gene expression and mtDNA content. Notably, high variability was observed in the mtDNA gene expression and content in each diagnostic group. Previous studies and the present work provide evidence for a role of mtDNA in SCH, BD and MDD. However, further studies with larger patient and control groups as well as by analyzing distinct brain regions are needed to elucidate the role of mtDNA in major psychiatric disorders.
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Affiliation(s)
- Helena Torrell
- Hospital Universitari Psiquiàtric Institut Pere Mata, IISPV, Universitat Rovira i Virgili. C/Sant Llorenç, Reus, Spain
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Cheng Z, Ito S, Nishio N, Thanasegaran S, Fang H, Isobe KI. Characteristics of cardiac aging in C57BL/6 mice. Exp Gerontol 2013; 48:341-8. [DOI: 10.1016/j.exger.2013.01.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 12/05/2012] [Accepted: 01/08/2013] [Indexed: 11/29/2022]
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Figge MT, Reichert AS, Meyer-Hermann M, Osiewacz HD. Deceleration of fusion-fission cycles improves mitochondrial quality control during aging. PLoS Comput Biol 2012; 8:e1002576. [PMID: 22761564 PMCID: PMC3386171 DOI: 10.1371/journal.pcbi.1002576] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 05/08/2012] [Indexed: 11/17/2022] Open
Abstract
Mitochondrial dynamics and mitophagy play a key role in ensuring mitochondrial quality control. Impairment thereof was proposed to be causative to neurodegenerative diseases, diabetes, and cancer. Accumulation of mitochondrial dysfunction was further linked to aging. Here we applied a probabilistic modeling approach integrating our current knowledge on mitochondrial biology allowing us to simulate mitochondrial function and quality control during aging in silico. We demonstrate that cycles of fusion and fission and mitophagy indeed are essential for ensuring a high average quality of mitochondria, even under conditions in which random molecular damage is present. Prompted by earlier observations that mitochondrial fission itself can cause a partial drop in mitochondrial membrane potential, we tested the consequences of mitochondrial dynamics being harmful on its own. Next to directly impairing mitochondrial function, pre-existing molecular damage may be propagated and enhanced across the mitochondrial population by content mixing. In this situation, such an infection-like phenomenon impairs mitochondrial quality control progressively. However, when imposing an age-dependent deceleration of cycles of fusion and fission, we observe a delay in the loss of average quality of mitochondria. This provides a rational why fusion and fission rates are reduced during aging and why loss of a mitochondrial fission factor can extend life span in fungi. We propose the ‘mitochondrial infectious damage adaptation’ (MIDA) model according to which a deceleration of fusion–fission cycles reflects a systemic adaptation increasing life span. Mitochondria are organelles that play a central role as ‘cellular power plants’. The cellular organization of these organelles involves a dynamic spatial network where mitochondria constantly undergo fusion and fission associated with the mixing of their molecular content. Together with the processes of mitophagy and biogenesis of mitochondrial mass, this results into a cellular surveillance system for maintaining their bioenergetic quality. The accumulation of molecular damage in mitochondria is associated with various human disorders and with aging. However, how these processes affect aging and how they can be reconciled with existing aging theories is just at the beginning to be considered. Mathematical modeling allows simulating the dynamics of mitochondrial quality control during aging in silico and leads to the ‘mitochondrial infectious damage adaptation’ (MIDA) model of aging. It reconciles a number of counterintuitive observations obtained during the last decade including infection-like processes of molecular damage spread, the reduction of fusion and fission rates during cellular aging, and observed life span extension for reduced mitochondrial fission. Interestingly, the MIDA model suggests that a reduction in mitochondrial dynamics rather than being merely a sign or even cause of aging, may actually reflect a systemic adaptation to prolong organismic life span.
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Affiliation(s)
- Marc Thilo Figge
- Applied Systems Biology, Leibniz-Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute and Friedrich Schiller University, Jena, Germany
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Wu CY, Chen YF, Wang CH, Kao CH, Zhuang HW, Chen CC, Chen LK, Kirby R, Wei YH, Tsai SF, Tsai TF. A persistent level of Cisd2 extends healthy lifespan and delays aging in mice. Hum Mol Genet 2012; 21:3956-68. [PMID: 22661501 DOI: 10.1093/hmg/dds210] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The CISD2 gene, which is an evolutionarily conserved novel gene, encodes a transmembrane protein primarily associated with the mitochondrial outer membrane. Significantly, the CISD2 gene is located within the candidate region on chromosome 4q where a genetic component for human longevity has been mapped. Previously, we have shown that Cisd2 deficiency shortens lifespan resulting in premature aging in mice. Additionally, an age-dependent decrease in Cisd2 expression has been detected during normal aging. In this study, we demonstrate that a persistent level of Cisd2 achieved by transgenic expression in mice extends their median and maximum lifespan without any apparent deleterious side effects. Cisd2 also ameliorates age-associated degeneration of the skin, skeletal muscles and neurons. Moreover, Cisd2 protects mitochondria from age-associated damage and functional decline as well as attenuating the age-associated reduction in whole-body energy metabolism. These results suggest that Cisd2 is a fundamentally important regulator of lifespan and provide an experimental basis for exploring the candidacy of CISD2 in human longevity.
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Affiliation(s)
- Chia-Yu Wu
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan
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Zhao T, Huang X, Han L, Wang X, Cheng H, Zhao Y, Chen Q, Chen J, Cheng H, Xiao R, Zheng M. Central role of mitofusin 2 in autophagosome-lysosome fusion in cardiomyocytes. J Biol Chem 2012; 287:23615-25. [PMID: 22619176 DOI: 10.1074/jbc.m112.379164] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the heart, autophagy has been implicated in cardioprotection and ischemia-reperfusion tolerance, and the dysregulation of autophagy is associated with the development of heart failure. Mitochondrial dynamic proteins are profoundly involved in autophagic processes, especially the initiation and formation of autophagosomes, but it is not clear whether they play any role in cardiac autophagy. We previously reported that mitofusin 2 (MFN2), a mitochondrial outer membrane protein, serves as a major determinant of cardiomyocyte apoptosis mediated by oxidative stress. Here, we reveal a novel and essential role of MFN2 in mediating cardiac autophagy. We found that specific deletion of MFN2 in cardiomyocytes caused extensive accumulation of autophagosomes. In particular, the fusion of autophagosomes with lysosomes, a critical step in autophagic degradation, was markedly retarded without altering the formation of autophagosomes and lysosomes in response to ischemia-reperfusion stress. Importantly, MFN2 co-immunoprecipitated with RAB7 in the heart, and starvation further increased it. Knockdown of MFN2 by shRNA prevented, whereas re-expression of MFN2 restored, the autophagosome-lysosome fusion in neonatal cardiomyocytes. Hearts from cardiac-specific MFN2 knock-out mice had abnormal mitochondrial and cellular metabolism and were vulnerable to ischemia-reperfusion challenge. Our study defined a novel and essential role of MFN2 in the cardiac autophagic process by mediating the maturation of autophagy at the phase of autophagosome-lysosome fusion; deficiency of MFN2 caused multiple molecular and functional defects that undermined cardiac reserve and gradually led to cardiac vulnerability and dysfunction.
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Affiliation(s)
- Ting Zhao
- Institute of Molecular Medicine, State Key Laboratory of Biomembrane and Membrane Biotechnology, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
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Role of pyrimidine depletion in the mitochondrial cardiotoxicity of nucleoside analogue reverse transcriptase inhibitors. J Acquir Immune Defic Syndr 2011; 55:550-7. [PMID: 20827217 DOI: 10.1097/qai.0b013e3181f25946] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Long-term antiretroviral treatment with nucleoside analogue reverse transcriptase inhibitors (NRTI) may result in a cardiomyopathy due to mitochondrial DNA (mtDNA) depletion. An intact mitochondrial function is required for the synthesis of intramyocardial pyrimidine nucleotides, which in turn are building blocks of mtDNA. We investigated if NRTI-related cardiomyopathy can be prevented with pyrimidine precursors. METHODS Mice were fed with zidovudine or zalcitabine with or without simultaneous Mitocnol, a dietary supplement with high uridine bioavailability. Myocardia were examined after 9 weeks. RESULTS Both NRTI induced a cardiomyopathy with mitochondrial enlargement, a disrupted cristal architecture on electron microscopy and diminished myocardial mtDNA copy numbers. The myocardial mtDNA-encoded cytochrome c-oxidase I subunit was impaired more profoundly than the nucleus-encoded cytochrome c-oxidase IV subunit. The myocardial formation of reactive oxygen species and mtDNA mutations was enhanced in zidovudine and zalcitabine treated animals. Mitocnol attenuated or normalized all myocardial pathology when given with both NRTI, but by itself had no intrinsic effects and no apparent adverse effects. CONCLUSIONS Zidovudine and zalcitabine induce a mitochondrial cardiomyopathy, which is antagonized with uridine supplementation, implicating pyrimidine pool depletion in its pathogenesis. Pyrimidine pool replenishment may be exploited clinically because uridine is well tolerated.
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Xu SC, He MD, Lu YH, Li L, Zhong M, Zhang YW, Wang Y, Yu ZP, Zhou Z. Nickel exposure induces oxidative damage to mitochondrial DNA in Neuro2a cells: the neuroprotective roles of melatonin. J Pineal Res 2011; 51:426-33. [PMID: 21797922 DOI: 10.1111/j.1600-079x.2011.00906.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recent studies suggest that oxidative stress and mitochondrial dysfunction play important roles in the neurotoxicity of nickel. Because mitochondrial DNA (mtDNA) is highly vulnerable to oxidative stress and melatonin can efficiently protect mtDNA against oxidative damage in various pathological conditions, the aims of this study were to determine whether mtDNA oxidative damage was involved in the neurotoxicity of nickel and to assay the neuroprotective effects of melatonin in mtDNA. In this study, we exposed mouse neuroblastoma cell lines (Neuro2a) to different concentrations of nickel chloride (NiCl(2), 0.125, 0.25, and 0.5 mm) for 24 hr. We found that nickel significantly increased reactive oxygen species (ROS) production and mitochondrial superoxide levels. In addition, nickel exposure increased mitochondrial 8-hydroxyguanine (8-OHdG) content and reduced mtDNA content and mtDNA transcript levels. Consistent with this finding, nickel was found to destroy mtDNA nucleoid structure and decrease protein levels of Tfam, a key protein component for nucleoid organization. However, all the oxidative damage to mtDNA induced by nickel was efficiently attenuated by melatonin pretreatment. Our results suggest that oxidative damage to mtDNA may account for the neurotoxicity of nickel. Melatonin has great pharmacological potential in protecting mtDNA against the adverse effects of nickel in the nervous system.
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Affiliation(s)
- Shang-Cheng Xu
- Department of Occupational Health, Third Military Medical University, Chongqing, China
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