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Ru Y, Deng X, Chen J, Zhang L, Xu Z, Lv Q, Long S, Huang Z, Kong M, Guo J, Jiang M. Maternal age enhances purifying selection on pathogenic mutations in complex I genes of mammalian mtDNA. NATURE AGING 2024:10.1038/s43587-024-00672-6. [PMID: 39075271 DOI: 10.1038/s43587-024-00672-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Accepted: 06/14/2024] [Indexed: 07/31/2024]
Abstract
Mitochondrial diseases, caused mainly by pathogenic mitochondrial DNA (mtDNA) mutations, pose major challenges due to the lack of effective treatments. Investigating the patterns of maternal transmission of mitochondrial diseases could pave the way for preventive approaches. In this study, we used DddA-derived cytosine base editors (DdCBEs) to generate two mouse models, each haboring a single pathogenic mutation in complex I genes (ND1 and ND5), replicating those found in human patients. Our findings revealed that both mutations are under strong purifying selection during maternal transmission and occur predominantly during postnatal oocyte maturation, with increased protein synthesis playing a vital role. Interestingly, we discovered that maternal age intensifies the purifying selection, suggesting that older maternal age may offer a protective effect against the transmission of deleterious mtDNA mutations, contradicting the conventional notion that maternal age correlates with increased transmitted mtDNA mutations. As collecting comprehensive clinical data is needed to understand the relationship between maternal age and transmission patterns in humans, our findings may have profound implications for reproductive counseling of mitochondrial diseases, especially those involving complex I gene mutations.
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Affiliation(s)
- Yanfei Ru
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
| | - Xiaoling Deng
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
- Fudan University, Shanghai, China
| | - Jiatong Chen
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Leping Zhang
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Zhe Xu
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
| | - Qunyu Lv
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Shiyun Long
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Zijian Huang
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
- Fudan University, Shanghai, China
| | - Minghua Kong
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, China
| | - Jing Guo
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China
- NHC Key Laboratory of Human Stem Cell and Reproductive Engineering, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Min Jiang
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China.
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences,Westlake University, Hangzhou, China.
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, China.
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2
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Tiberi J, Cesarini V, Stefanelli R, Canterini S, Fiorenza MT, Rosa PL. Sex differences in antioxidant defence and the regulation of redox homeostasis in physiology and pathology. Mech Ageing Dev 2023; 211:111802. [PMID: 36958540 DOI: 10.1016/j.mad.2023.111802] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/14/2023] [Accepted: 03/20/2023] [Indexed: 03/25/2023]
Abstract
Reactive oxygen species (ROS) is a term that defines a group of unstable compounds derived from exogenous sources or endogenous metabolism. Under physiological conditions, low levels of ROS play a key role in the regulation of signal transduction- or transcription-mediated cellular responses. In contrast, excessive and uncontrolled loading of ROS results in a pathological state known as oxidative stress (OS), a leading contributor to aging and a pivotal factor for the onset and progression of many disorders. Evolution has endowed cells with an antioxidant system involved in stabilizing ROS levels to a specific threshold, preserving ROS-induced signalling function and limiting negative side effects. In mammals, a great deal of evidence indicates that females defence against ROS is more proficient than males, determining a longer lifespan and lower incidence of most chronic diseases. In this review, we will summarize the most recent sex-related differences in the regulation of redox homeostasis. We will highlight the peculiar aspects of the antioxidant defence in sex-biased diseases whose onset or progression is driven by OS, and we will discuss the molecular, genetic, and evolutionary determinants of female proficiency to cope with ROS.
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Affiliation(s)
- Jessica Tiberi
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy; PhD program in Behavioral Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Valeriana Cesarini
- Department of Biomedicine Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Roberta Stefanelli
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Sonia Canterini
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy; European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Maria Teresa Fiorenza
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy; European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Piergiorgio La Rosa
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy; European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy.
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3
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Rozsivalova DH, Popovic M, Kaul H, Trifunovic A. Isolation of Functional Mitochondria and Pure mtDNA from Murine Tissues. Methods Mol Biol 2023; 2615:3-16. [PMID: 36807780 DOI: 10.1007/978-1-0716-2922-2_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Detailed analysis of mitochondrial function cannot be achieved without good quality preparations of isolated mitochondria. Ideally, the isolation protocol should be quick, while producing a reasonably pure pool of mitochondria that are still intact and coupled. Here, we describe a fast and simple method for the purification of mammalian mitochondria relying on isopycnic density gradient centrifugation. We describe specific steps that should be taken into consideration when functional mitochondria from different tissues should be isolated. This protocol is suitable for the analysis of many aspects of the organelle's structure and function.
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Affiliation(s)
- Dieu Hien Rozsivalova
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Milica Popovic
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Harshita Kaul
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Aleksandra Trifunovic
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany.
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4
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Sanchez-Contreras M, Sweetwyne MT, Tsantilas KA, Whitson JA, Campbell MD, Kohrn BF, Kim HJ, Hipp MJ, Fredrickson J, Nguyen MM, Hurley JB, Marcinek DJ, Rabinovitch PS, Kennedy SR. The multi-tissue landscape of somatic mtDNA mutations indicates tissue-specific accumulation and removal in aging. eLife 2023; 12:e83395. [PMID: 36799304 PMCID: PMC10072880 DOI: 10.7554/elife.83395] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 02/15/2023] [Indexed: 02/18/2023] Open
Abstract
Accumulation of somatic mutations in the mitochondrial genome (mtDNA) has long been proposed as a possible mechanism of mitochondrial and tissue dysfunction that occurs during aging. A thorough characterization of age-associated mtDNA somatic mutations has been hampered by the limited ability to detect low-frequency mutations. Here, we used Duplex Sequencing on eight tissues of an aged mouse cohort to detect >89,000 independent somatic mtDNA mutations and show significant tissue-specific increases during aging across all tissues examined which did not correlate with mitochondrial content and tissue function. G→A/C→T substitutions, indicative of replication errors and/or cytidine deamination, were the predominant mutation type across all tissues and increased with age, whereas G→T/C→A substitutions, indicative of oxidative damage, were the second most common mutation type, but did not increase with age regardless of tissue. We also show that clonal expansions of mtDNA mutations with age is tissue- and mutation type-dependent. Unexpectedly, mutations associated with oxidative damage rarely formed clones in any tissue and were significantly reduced in the hearts and kidneys of aged mice treated at late age with elamipretide or nicotinamide mononucleotide. Thus, the lack of accumulation of oxidative damage-linked mutations with age suggests a life-long dynamic clearance of either the oxidative lesions or mtDNA genomes harboring oxidative damage.
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Affiliation(s)
| | - Mariya T Sweetwyne
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | | | - Jeremy A Whitson
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | | | - Brenden F Kohrn
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | - Hyeon Jeong Kim
- Department of Biology, University of WashingtonSeattleUnited States
| | - Michael J Hipp
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | - Jeanne Fredrickson
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | - Megan M Nguyen
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | - James B Hurley
- Department of Biochemistry, University of WashingtonSeattleUnited States
| | - David J Marcinek
- Department of Radiology, University of WashingtonSeattleUnited States
| | - Peter S Rabinovitch
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | - Scott R Kennedy
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
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5
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Zhao C, Yang Z, Gong S, Du Z. Adenovirus-mediated SIRT1 protects cochlear strial marginal cells in a D-gal-induced senescent model in vitro. Mol Biol Rep 2023; 50:541-551. [PMID: 36350417 DOI: 10.1007/s11033-022-08032-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/13/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND A primary obstacle in age-related hearing loss (ARHL) study is the lack of accelerated senescent models in vitro that explore the precise underlying mechanism in different types of ARHL. The damage to strial marginal cells (SMCs) is a subset of strial presbycusis-associated pathological changes. We aimed to establish a D-galactose (D-gal)-induced SMCs senescent model and study the effect of deacetylase sirtuin 1 (SIRT1) on presbycusis in vitro. METHODS SMCs from C57BL/6J neonatal mice were cultured and treated with D-gal to establish accelerated senescent models. And then D-gal-induced SMCs were transfected with adenovirus (Ad)-SIRT1-GFP or Ad-GFP. Oxidative stress and mitochondrial DNA (mtDNA) damage were determined by histological analysis or RT-PCR. Western blotting (WB) and RT-PCR were used to evaluate protein and mRNA levels of superoxide dismutase 2 (SOD2) and SIRT1, respectively. Additionally, apoptosis was investigated by WB and TUNEL staining. RESULTS D-gal-induced SMCs exhibited several characteristics of senescence, including increased the level of 8-hydroxy-2'-deoxyguanosine, which is a marker of DNA oxidative damage, and elevated the amount of mtDNA 3860-bp deletion, which is a common type of mtDNA damage in the auditory system of mice. SIRT1 overexpression effectively inhibited these changes by upregulating the level of SOD2, thereby inhibiting cytochrome c translocation from mitochondria to cytoplasm, inhibiting cell apoptosis, and ultimately delaying aging in the D-gal-induced senescent SMCs. CONCLUSIONS Altogether, the evidence suggests that the D-gal-induced SMCs accelerated aging model is successfully established, and SIRT1 overexpression protects SMCs against oxidative stress by enhancing SOD2 expression in ARHL.
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Affiliation(s)
- Chunli Zhao
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No. 95, Yong'an Road, Xicheng District, Beijing, 100050, China.,Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China
| | - Zijing Yang
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No. 95, Yong'an Road, Xicheng District, Beijing, 100050, China.,Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China
| | - Shusheng Gong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No. 95, Yong'an Road, Xicheng District, Beijing, 100050, China. .,Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China.
| | - Zhengde Du
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No. 95, Yong'an Road, Xicheng District, Beijing, 100050, China. .,Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China.
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6
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Huang X, Zeng Z, Li S, Xie Y, Tong X. The Therapeutic Strategies Targeting Mitochondrial Metabolism in Cardiovascular Disease. Pharmaceutics 2022; 14:pharmaceutics14122760. [PMID: 36559254 PMCID: PMC9788260 DOI: 10.3390/pharmaceutics14122760] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
Cardiovascular disease (CVD) is a group of systemic disorders threatening human health with complex pathogenesis, among which mitochondrial energy metabolism reprogramming has a critical role. Mitochondria are cell organelles that fuel the energy essential for biochemical reactions and maintain normal physiological functions of the body. Mitochondrial metabolic disorders are extensively involved in the progression of CVD, especially for energy-demanding organs such as the heart. Therefore, elucidating the role of mitochondrial metabolism in the progression of CVD is of great significance to further understand the pathogenesis of CVD and explore preventive and therapeutic methods. In this review, we discuss the major factors of mitochondrial metabolism and their potential roles in the prevention and treatment of CVD. The current application of mitochondria-targeted therapeutic agents in the treatment of CVD and advances in mitochondria-targeted gene therapy technologies are also overviewed.
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Affiliation(s)
- Xiaoyang Huang
- Department of Pharmacology and Pharmacy, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Zhenhua Zeng
- Biomedical Research Center, Hunan University of Medicine, Huaihua 418000, China
| | - Siqi Li
- Department of Pharmacology and Pharmacy, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
- Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Yufei Xie
- Department of Pharmacology and Pharmacy, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Xiaoyong Tong
- Department of Pharmacology and Pharmacy, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
- Jinfeng Laboratory, Chongqing 401329, China
- Correspondence:
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7
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Kim M, Mahmood M, Reznik E, Gammage PA. Mitochondrial DNA is a major source of driver mutations in cancer. Trends Cancer 2022; 8:1046-1059. [PMID: 36041967 PMCID: PMC9671861 DOI: 10.1016/j.trecan.2022.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 12/24/2022]
Abstract
Mitochondrial DNA (mtDNA) mutations are among the most common genetic events in all tumors and directly impact metabolic homeostasis. Despite the central role mitochondria play in energy metabolism and cellular physiology, the role of mutations in the mitochondrial genomes of tumors has been contentious. Until recently, genomic and functional studies of mtDNA variants were impeded by a lack of adequate tumor mtDNA sequencing data and available methods for mitochondrial genome engineering. These barriers and a conceptual fog surrounding the functional impact of mtDNA mutations in tumors have begun to lift, revealing a path to understanding the role of this essential metabolic genome in cancer initiation and progression. Here we discuss the history, recent developments, and challenges that remain for mitochondrial oncogenetics as the impact of a major new class of cancer-associated mutations is unveiled.
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Affiliation(s)
- Minsoo Kim
- Computational Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | - Ed Reznik
- Computational Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Marie-Josée and Henry R. Kravis Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Urology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Payam A Gammage
- CRUK Beatson Institute, Glasgow, UK; Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
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8
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Approaches to Mitigate Mitochondrial Dysfunction in Sensorineural Hearing Loss. Ann Biomed Eng 2022; 50:1762-1770. [PMID: 36369597 DOI: 10.1007/s10439-022-03103-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/18/2022] [Indexed: 11/13/2022]
Abstract
Mitochondria are highly dynamic multifaceted organelles with various functions including cellular energy metabolism, reactive oxygen species (ROS) generation, calcium homeostasis, and apoptosis. Because of these diverse functions, mitochondria are key regulators of cell survival and death, and their dysfunction is implicated in numerous diseases, particularly neurodegenerative disorders such as Alzheimer's Disease, Parkinson's Disease, and Huntington's Disease. One of the most common neurodegenerative disorders is sensorineural hearing loss (SNHL). SNHL primarily originates from the degenerative changes in the cochlea, which is the auditory portion of the inner ear. Many cochlear cells contain an abundance of mitochondria and are metabolically highly active, rendering them susceptible to mitochondrial dysfunction. Indeed, the causal role of mitochondrial dysfunction in SNHL progression is well established, and therefore, targeted for treatment. In this review, we aim to compile the emerging findings in the literature indicating the role of mitochondrial dysfunction in the progression of sensorineural hearing loss and highlight potential therapeutics targeting mitochondrial dysfunction for hearing loss treatment.
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9
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Akbari M, Nilsen HL, Montaldo NP. Dynamic features of human mitochondrial DNA maintenance and transcription. Front Cell Dev Biol 2022; 10:984245. [PMID: 36158192 PMCID: PMC9491825 DOI: 10.3389/fcell.2022.984245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/02/2022] [Indexed: 12/03/2022] Open
Abstract
Mitochondria are the primary sites for cellular energy production and are required for many essential cellular processes. Mitochondrial DNA (mtDNA) is a 16.6 kb circular DNA molecule that encodes only 13 gene products of the approximately 90 different proteins of the respiratory chain complexes and an estimated 1,200 mitochondrial proteins. MtDNA is, however, crucial for organismal development, normal function, and survival. MtDNA maintenance requires mitochondrially targeted nuclear DNA repair enzymes, a mtDNA replisome that is unique to mitochondria, and systems that control mitochondrial morphology and quality control. Here, we provide an overview of the current literature on mtDNA repair and transcription machineries and discuss how dynamic functional interactions between the components of these systems regulate mtDNA maintenance and transcription. A profound understanding of the molecular mechanisms that control mtDNA maintenance and transcription is important as loss of mtDNA integrity is implicated in normal process of aging, inflammation, and the etiology and pathogenesis of a number of diseases.
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Affiliation(s)
- Mansour Akbari
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Hilde Loge Nilsen
- Department of Clinical Molecular Biology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Unit for precision medicine, Akershus University Hospital, Nordbyhagen, Norway
- Department of Microbiology, Oslo University Hospital, Oslo, Norway
| | - Nicola Pietro Montaldo
- Department of Clinical Molecular Biology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- *Correspondence: Nicola Pietro Montaldo,
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Leuthner T, Benzing L, Kohrn B, Bergemann C, Hipp M, Hershberger K, Mello D, Sokolskyi T, Stevenson K, Merutka I, Seay S, Gregory S, Kennedy S, Meyer J. Resistance of mitochondrial DNA to cadmium and Aflatoxin B1 damage-induced germline mutation accumulation in C. elegans. Nucleic Acids Res 2022; 50:8626-8642. [PMID: 35947695 PMCID: PMC9410910 DOI: 10.1093/nar/gkac666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/11/2022] [Accepted: 07/22/2022] [Indexed: 01/12/2023] Open
Abstract
Mitochondrial DNA (mtDNA) is prone to mutation in aging and over evolutionary time, yet the processes that regulate the accumulation of de novo mtDNA mutations and modulate mtDNA heteroplasmy are not fully elucidated. Mitochondria lack certain DNA repair processes, which could contribute to polymerase error-induced mutations and increase susceptibility to chemical-induced mtDNA mutagenesis. We conducted error-corrected, ultra-sensitive Duplex Sequencing to investigate the effects of two known nuclear genome mutagens, cadmium and Aflatoxin B1, on germline mtDNA mutagenesis in Caenorhabditis elegans. Detection of thousands of mtDNA mutations revealed pervasive heteroplasmy in C. elegans and that mtDNA mutagenesis is dominated by C:G → A:T mutations generally attributed to oxidative damage. However, there was no effect of either exposure on mtDNA mutation frequency, spectrum, or trinucleotide context signature despite a significant increase in nuclear mutation rate after aflatoxin B1 exposure. Mitophagy-deficient mutants pink-1 and dct-1 accumulated significantly higher levels of mtDNA damage compared to wild-type C. elegans after exposures. However, there were only small differences in mtDNA mutation frequency, spectrum, or trinucleotide context signature compared to wild-type after 3050 generations, across all treatments. These findings suggest mitochondria harbor additional previously uncharacterized mechanisms that regulate mtDNA mutational processes across generations.
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Affiliation(s)
- Tess C Leuthner
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Laura Benzing
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Brendan F Kohrn
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | | | - Michael J Hipp
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | | | - Danielle F Mello
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Tymofii Sokolskyi
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Kevin Stevenson
- Duke Molecular Physiology Institute, Duke University, Durham, NC 27701, USA
| | - Ilaria R Merutka
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Sarah A Seay
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Simon G Gregory
- Duke Molecular Physiology Institute, Duke University, Durham, NC 27701, USA,Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Scott R Kennedy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Joel N Meyer
- To whom correspondence should be addressed. Tel: +1 919 613 8109;
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11
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Pudlarz AM, Ranoszek-Soliwoda K, Karbownik MS, Czechowska E, Tomaszewska E, Celichowski G, Grobelny J, Chabielska E, Gromotowicz-Popławska A, Szemraj J. Antioxidant enzymes immobilized on gold and silver nanoparticles enhance DNA repairing systems of rat skin after exposure to ultraviolet radiation. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2022; 43:102558. [PMID: 35390524 DOI: 10.1016/j.nano.2022.102558] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 03/08/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
The aim of the study was to investigate in vivo whether the application of immobilized superoxide dismutase (SOD) and catalase (CAT) could enhance DNA repairing systems and reduce level of CPD (cyclobutane pyrimidine dimers) and 6-4PP ((6-4) pyrimidine-pyrimidone photoproducts), and whether the immobilization on gold (AuNPs) and silver (AgNPs) nanoparticles affects the outcome. The study presents secondary analysis of our previous research. Three-day application of SOD and CAT in all forms of solution decreased the levels of CPD and 6-4PP boosted by UV irradiation. The mRNA expression level of the nucleotide excision repair (NER) system genes (XPA, XPC, ERCC1, ERCC2, ERCC3, LIG1) increased after application of immobilized and free enzymes. Increased by UV irradiation, p53 mRNA expression level normalized with the enzyme application. In conclusion, application of free and immobilized antioxidant enzymes accelerates removal of harmful effects of UV radiation in the rat skin by increasing expression level of NER genes.
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Affiliation(s)
- Agnieszka M Pudlarz
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland.
| | | | - Michał S Karbownik
- Department of Pharmacology and Toxicology, Medical University of Lodz, Lodz, Poland
| | - Ewa Czechowska
- Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, Lodz, Poland
| | - Emilia Tomaszewska
- Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, Lodz, Poland
| | - Grzegorz Celichowski
- Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, Lodz, Poland
| | - Jarosław Grobelny
- Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, Lodz, Poland
| | - Ewa Chabielska
- Department of Biopharmacy, Medical University of Bialystok, Bialystok, Poland
| | | | - Janusz Szemraj
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland; Department of Medicine, Lazarski University, Warsaw, Poland.
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12
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Chen Y, Hamidu S, Yang X, Yan Y, Wang Q, Li L, Oduro PK, Li Y. Dietary Supplements and Natural Products: An Update on Their Clinical Effectiveness and Molecular Mechanisms of Action During Accelerated Biological Aging. Front Genet 2022; 13:880421. [PMID: 35571015 PMCID: PMC9096086 DOI: 10.3389/fgene.2022.880421] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 04/04/2022] [Indexed: 12/11/2022] Open
Abstract
Accelerated biological aging, which involves the gradual decline of organ or tissue functions and the distortion of physiological processes, underlies several human diseases. Away from the earlier free radical concept, telomere attrition, cellular senescence, proteostasis loss, mitochondrial dysfunction, stem cell exhaustion, and epigenetic and genomic alterations have emerged as biological hallmarks of aging. Moreover, nutrient-sensing metabolic pathways are critical to an organism’s ability to sense and respond to nutrient levels. Pharmaceutical, genetic, and nutritional interventions reverting physiological declines by targeting nutrient-sensing metabolic pathways can promote healthy aging and increase lifespan. On this basis, biological aging hallmarks and nutrient-sensing dependent and independent pathways represent evolving drug targets for many age-linked diseases. Here, we discuss and update the scientific community on contemporary advances in how dietary supplements and natural products beneficially revert accelerated biological aging processes to retrograde human aging and age-dependent human diseases, both from the clinical and preclinical studies point-of-view. Overall, our review suggests that dietary/natural products increase healthspan—rather than lifespan—effectively minimizing the period of frailty at the end of life. However, real-world setting clinical trials and basic studies on dietary supplements and natural products are further required to decisively demonstrate whether dietary/natural products could promote human lifespan.
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Affiliation(s)
- Ye Chen
- State Key Laboratory of Pharmacology of Modern Chinese Medicine, Department of Pharmacology and Toxicology, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Sherif Hamidu
- Clinical Pathology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Xintong Yang
- State Key Laboratory of Pharmacology of Modern Chinese Medicine, Department of Pharmacology and Toxicology, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yiqi Yan
- State Key Laboratory of Pharmacology of Modern Chinese Medicine, Department of Pharmacology and Toxicology, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Qilong Wang
- State Key Laboratory of Pharmacology of Modern Chinese Medicine, Department of Pharmacology and Toxicology, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Lin Li
- State Key Laboratory of Pharmacology of Modern Chinese Medicine, Department of Pharmacology and Toxicology, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Patrick Kwabena Oduro
- State Key Laboratory of Pharmacology of Modern Chinese Medicine, Department of Pharmacology and Toxicology, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Clinical Pathology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Yuhong Li
- State Key Laboratory of Pharmacology of Modern Chinese Medicine, Department of Pharmacology and Toxicology, Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
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13
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Abstract
Significance: Aging is a natural process that affects most living organisms, resulting in increased mortality. As the world population ages, the prevalence of age-associated diseases, and their associated health care costs, has increased sharply. A better understanding of the molecular mechanisms that lead to cellular dysfunction may provide important targets for interventions to prevent or treat these diseases. Recent Advances: Although the mitochondrial theory of aging had been proposed more than 40 years ago, recent new data have given stronger support for a central role for mitochondrial dysfunction in several pathways that are deregulated during normal aging and age-associated disease. Critical Issues: Several of the experimental evidence linking mitochondrial alterations to age-associated loss of function are correlative and mechanistic insights are still elusive. Here, we review how mitochondrial dysfunction may be involved in many of the known hallmarks of aging, and how these pathways interact in an intricate net of molecular relationships. Future Directions: As it has become clear that mitochondrial dysfunction plays causative roles in normal aging and age-associated diseases, it is necessary to better define the molecular interactions and the temporal and causal relationship between these changes and the relevant phenotypes seen during the aging process. Antioxid. Redox Signal. 36, 824-843.
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Affiliation(s)
- Caio M P F Batalha
- Lab. Genética Mitocondrial, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Anibal Eugênio Vercesi
- Departamento de Patologia Clínica, Faculdade de Medicina, Universidade de Campinas, Campinas, Brazil
| | - Nadja C Souza-Pinto
- Lab. Genética Mitocondrial, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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14
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Abstract
Significance: The small, multicopy mitochondrial genome (mitochondrial DNA [mtDNA]) is essential for efficient energy production, as alterations in its coding information or a decrease in its copy number disrupt mitochondrial ATP synthesis. However, the mitochondrial replication machinery encounters numerous challenges that may limit its ability to duplicate this important genome and that jeopardize mtDNA stability, including various lesions in the DNA template, topological stress, and an insufficient nucleotide supply. Recent Advances: An ever-growing array of DNA repair or maintenance factors are being reported to localize to the mitochondria. We review current knowledge regarding the mitochondrial factors that may contribute to the tolerance or repair of various types of changes in the mitochondrial genome, such as base damage, incorporated ribonucleotides, and strand breaks. We also discuss the newly discovered link between mtDNA instability and activation of the innate immune response. Critical Issues: By which mechanisms do mitochondria respond to challenges that threaten mtDNA maintenance? What types of mtDNA damage are repaired, and when are the affected molecules degraded instead? And, finally, which forms of mtDNA instability trigger an immune response, and how? Future Directions: Further work is required to understand the contribution of the DNA repair and damage-tolerance factors present in the mitochondrial compartment, as well as the balance between mtDNA repair and degradation. Finally, efforts to understand the events underlying mtDNA release into the cytosol are warranted. Pursuing these and many related avenues can improve our understanding of what goes wrong in mitochondrial disease. Antioxid. Redox Signal. 36, 885-905.
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Affiliation(s)
- Gustavo Carvalho
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Bruno Marçal Repolês
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Isabela Mendes
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Paulina H Wanrooij
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
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15
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Arbeithuber B, Cremona MA, Hester J, Barrett A, Higgins B, Anthony K, Chiaromonte F, Diaz FJ, Makova KD. Advanced age increases frequencies of de novo mitochondrial mutations in macaque oocytes and somatic tissues. Proc Natl Acad Sci U S A 2022; 119:e2118740119. [PMID: 35394879 PMCID: PMC9169796 DOI: 10.1073/pnas.2118740119] [Citation(s) in RCA: 14] [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: 10/19/2021] [Accepted: 02/25/2022] [Indexed: 12/18/2022] Open
Abstract
Mutations in mitochondrial DNA (mtDNA) contribute to multiple diseases. However, how new mtDNA mutations arise and accumulate with age remains understudied because of the high error rates of current sequencing technologies. Duplex sequencing reduces error rates by several orders of magnitude via independently tagging and analyzing each of the two template DNA strands. Here, using duplex sequencing, we obtained high-quality mtDNA sequences for somatic tissues (liver and skeletal muscle) and single oocytes of 30 unrelated rhesus macaques, from 1 to 23 y of age. Sequencing single oocytes minimized effects of natural selection on germline mutations. In total, we identified 17,637 tissue-specific de novo mutations. Their frequency increased ∼3.5-fold in liver and ∼2.8-fold in muscle over the ∼20 y assessed. Mutation frequency in oocytes increased ∼2.5-fold until the age of 9 y, but did not increase after that, suggesting that oocytes of older animals maintain the quality of their mtDNA. We found the light-strand origin of replication (OriL) to be a hotspot for mutation accumulation with aging in liver. Indeed, the 33-nucleotide-long OriL harbored 12 variant hotspots, 10 of which likely disrupt its hairpin structure and affect replication efficiency. Moreover, in somatic tissues, protein-coding variants were subject to positive selection (potentially mitigating toxic effects of mitochondrial activity), the strength of which increased with the number of macaques harboring variants. Our work illuminates the origins and accumulation of somatic and germline mtDNA mutations with aging in primates and has implications for delayed reproduction in modern human societies.
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Affiliation(s)
- Barbara Arbeithuber
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
- Experimental Gynaecology, Obstetrics and Gynaecological Endocrinology, Kepler University Hospital Linz, Johannes Kepler University Linz, 4020 Linz, Austria
| | - Marzia A. Cremona
- Department of Operations and Decision Systems, Université Laval, Québec, QC G1V0A6, Canada
- Population Health and Optimal Health Practices, CHU de Québec - Université Laval Research Center, Québec, QC G1V4G2, Canada
- Center for Medical Genomics, The Pennsylvania State University, University Park, PA 16802
| | - James Hester
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802
| | - Alison Barrett
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - Bonnie Higgins
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - Kate Anthony
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - Francesca Chiaromonte
- Center for Medical Genomics, The Pennsylvania State University, University Park, PA 16802
- Department of Statistics, The Pennsylvania State University, University Park, PA 16802
- Institute of Economics and EMbeDS, Sant'Anna School of Advanced Studies, Pisa 56127, Italy
| | - Francisco J. Diaz
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802
| | - Kateryna D. Makova
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
- Center for Medical Genomics, The Pennsylvania State University, University Park, PA 16802
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16
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Manini A, Abati E, Comi GP, Corti S, Ronchi D. Mitochondrial DNA homeostasis impairment and dopaminergic dysfunction: A trembling balance. Ageing Res Rev 2022; 76:101578. [PMID: 35114397 DOI: 10.1016/j.arr.2022.101578] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/26/2021] [Accepted: 01/28/2022] [Indexed: 02/07/2023]
Abstract
Maintenance of mitochondrial DNA (mtDNA) homeostasis includes a variety of processes, such as mtDNA replication, repair, and nucleotides synthesis, aimed at preserving the structural and functional integrity of mtDNA molecules. Mutations in several nuclear genes (i.e., POLG, POLG2, TWNK, OPA1, DGUOK, MPV17, TYMP) impair mtDNA maintenance, leading to clinical syndromes characterized by mtDNA depletion and/or deletions in affected tissues. In the past decades, studies have demonstrated a progressive accumulation of multiple mtDNA deletions in dopaminergic neurons of the substantia nigra in elderly population and, to a greater extent, in Parkinson's disease patients. Moreover, parkinsonism has been frequently described as a prominent clinical feature in mtDNA instability syndromes. Among Parkinson's disease-related genes with a significant role in mitochondrial biology, PARK2 and LRRK2 specifically take part in mtDNA maintenance. Moreover, a variety of murine models (i.e., "Mutator", "MitoPark", "PD-mitoPstI", "Deletor", "Twinkle-dup" and "TwinkPark") provided in vivo evidence that mtDNA stability is required to preserve nigrostriatal integrity. Here, we review and discuss the clinical, genetic, and pathological background underlining the link between impaired mtDNA homeostasis and dopaminergic degeneration.
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17
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Silva-Pinheiro P, Minczuk M. The potential of mitochondrial genome engineering. Nat Rev Genet 2022; 23:199-214. [PMID: 34857922 DOI: 10.1038/s41576-021-00432-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2021] [Indexed: 12/19/2022]
Abstract
Mitochondria are subject to unique genetic control by both nuclear DNA and their own genome, mitochondrial DNA (mtDNA), of which each mitochondrion contains multiple copies. In humans, mutations in mtDNA can lead to devastating, heritable, multi-system diseases that display different tissue-specific presentation at any stage of life. Despite rapid advances in nuclear genome engineering, for years, mammalian mtDNA has remained resistant to genetic manipulation, hampering our ability to understand the mechanisms that underpin mitochondrial disease. Recent developments in the genetic modification of mammalian mtDNA raise the possibility of using genome editing technologies, such as programmable nucleases and base editors, for the treatment of hereditary mitochondrial disease.
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Affiliation(s)
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
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18
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Abstract
Mitochondria are the main source of energy used to maintain cellular homeostasis. This aspect of mitochondrial biology underlies their putative role in age-associated tissue dysfunction. Proper functioning of the electron transport chain (ETC), which is partially encoded by the extra-nuclear mitochondrial genome (mtDNA), is key to maintaining this energy production. The acquisition of de novo somatic mutations that interrupt the function of the ETC have long been associated with aging and common diseases of the elderly. Yet, despite over 30 years of study, the exact role(s) mtDNA mutations play in driving aging and its associated pathologies remains under considerable debate. Furthermore, even fundamental aspects of age-related mtDNA mutagenesis, such as when mutations arise during aging, where and how often they occur across tissues, and the specific mechanisms that give rise to them, remain poorly understood. In this review, we address the current understanding of the somatic mtDNA mutations, with an emphasis of when, where, and how these mutations arise during aging. Additionally, we highlight current limitations in our knowledge and critically evaluate the controversies stemming from these limitations. Lastly, we highlight new and emerging technologies that offer potential ways forward in increasing our understanding of somatic mtDNA mutagenesis in the aging process.
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Affiliation(s)
- Monica Sanchez-Contreras
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
| | - Scott R Kennedy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
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19
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Maclaine KD, Stebbings KA, Llano DA, Havird JC. The mtDNA mutation spectrum in the PolG mutator mouse reveals germline and somatic selection. BMC Genom Data 2021; 22:52. [PMID: 34823474 PMCID: PMC8620558 DOI: 10.1186/s12863-021-01005-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Mitochondrial DNA (mtDNA) codes for products necessary for electron transport and mitochondrial gene translation. mtDNA mutations can lead to human disease and influence organismal fitness. The PolG mutator mouse lacks mtDNA proofreading function and rapidly accumulates mtDNA mutations, making it a model for examining the causes and consequences of mitochondrial mutations. Premature aging in PolG mice and their physiology have been examined in depth, but the location, frequency, and diversity of their mtDNA mutations remain understudied. Identifying the locations and spectra of mtDNA mutations in PolG mice can shed light on how selection shapes mtDNA, both within and across organisms. RESULTS Here, we characterized somatic and germline mtDNA mutations in brain and liver tissue of PolG mice to quantify mutation count (number of unique mutations) and frequency (mutation prevalence). Overall, mtDNA mutation count and frequency were the lowest in the D-loop, where an mtDNA origin of replication is located, but otherwise uniform across the mitochondrial genome. Somatic mtDNA mutations have a higher mutation count than germline mutations. However, germline mutations maintain a higher frequency and were also more likely to be silent. Cytosine to thymine mutations characteristic of replication errors were the plurality of basepair changes, and missense C to T mutations primarily resulted in increased protein hydrophobicity. Unlike wild type mice, PolG mice do not appear to show strand asymmetry in mtDNA mutations. Indel mutations had a lower count and frequency than point mutations and tended to be short, frameshift deletions. CONCLUSIONS Our results provide strong evidence that purifying selection plays a major role in the mtDNA of PolG mice. Missense mutations were less likely to be passed down in the germline, and they were less likely to spread to high frequencies. The D-loop appears to have resistance to mutations, either through selection or as a by-product of replication processes. Missense mutations that decrease hydrophobicity also tend to be selected against, reflecting the membrane-bound nature of mtDNA-encoded proteins. The abundance of mutations from polymerase errors compared with reactive oxygen species (ROS) damage supports previous studies suggesting ROS plays a minimal role in exacerbating the PolG phenotype, but our findings on strand asymmetry provide discussion for the role of polymerase errors in wild type organisms. Our results provide further insight on how selection shapes mtDNA mutations and on the aging mechanisms in PolG mice.
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Affiliation(s)
- Kendra D Maclaine
- Department of Integrative Biology, The University of Texas at Austin, 2415 Speedway #C0930, Austin, TX, 78712, USA.
| | - Kevin A Stebbings
- Neuroscience Program, The University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, 405 North Mathews Avenue, Urbana, IL, 61801, USA
| | - Daniel A Llano
- Neuroscience Program, The University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, 405 North Mathews Avenue, Urbana, IL, 61801, USA
- Department of Molecular an Integrative Physiology, 524 Burrill Hall, MC-114, 407 South Goodwin Avenue, Urbana, IL, 61801, USA
| | - Justin C Havird
- Department of Integrative Biology, The University of Texas at Austin, 2415 Speedway #C0930, Austin, TX, 78712, USA
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20
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Repolês BM, Gorospe CM, Tran P, Nilsson AK, Wanrooij PH. The integrity and assay performance of tissue mitochondrial DNA is considerably affected by choice of isolation method. Mitochondrion 2021; 61:179-187. [PMID: 34728429 DOI: 10.1016/j.mito.2021.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/07/2021] [Accepted: 10/25/2021] [Indexed: 10/19/2022]
Abstract
The integrity of mitochondrial DNA (mtDNA) isolated from solid tissues is critical for analyses such as long-range PCR, but is typically assessed under conditions that fail to provide information on the individual mtDNA strands. Using denaturing gel electrophoresis, we show that commonly-used isolation procedures generate mtDNA containing several single-strand breaks per strand. Through systematic comparison of DNA isolation methods, we identify a procedure yielding the highest integrity of mtDNA that we demonstrate displays improved performance in downstream assays. Our results highlight the importance of isolation method choice, and serve as a resource to researchers requiring high-quality mtDNA from solid tissues.
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Affiliation(s)
- Bruno Marçal Repolês
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Choco Michael Gorospe
- 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
| | - Anna Karin Nilsson
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Paulina H Wanrooij
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden.
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21
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Waneka G, Svendsen JM, Havird JC, Sloan DB. Mitochondrial mutations in Caenorhabditis elegans show signatures of oxidative damage and an AT-bias. Genetics 2021; 219:6346985. [PMID: 34849888 DOI: 10.1093/genetics/iyab116] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 07/09/2021] [Indexed: 01/25/2023] Open
Abstract
Rapid mutation rates are typical of mitochondrial genomes (mtDNAs) in animals, but it is not clear why. The difficulty of obtaining measurements of mtDNA mutation that are not biased by natural selection has stymied efforts to distinguish between competing hypotheses about the causes of high mtDNA mutation rates. Several studies which have measured mtDNA mutations in nematodes have yielded small datasets with conflicting conclusions about the relative abundance of different substitution classes (i.e., the mutation spectrum). We therefore leveraged Duplex Sequencing, a high-fidelity DNA sequencing technique, to characterize de novo mtDNA mutations in Caenorhabditis elegans. This approach detected nearly an order of magnitude more mtDNA mutations than documented in any previous nematode mutation study. Despite an existing extreme AT bias in the C. elegans mtDNA (75.6% AT), we found that a significant majority of mutations increase genomic AT content. Compared to some prior studies in nematodes and other animals, the mutation spectrum reported here contains an abundance of CG→AT transversions, supporting the hypothesis that oxidative damage may be a driver of mtDNA mutations in nematodes. Furthermore, we found an excess of G→T and C→T changes on the coding DNA strand relative to the template strand, consistent with increased exposure to oxidative damage. Analysis of the distribution of mutations across the mtDNA revealed significant variation among protein-coding genes and as well as among neighboring nucleotides. This high-resolution view of mitochondrial mutations in C. elegans highlights the value of this system for understanding relationships among oxidative damage, replication error, and mtDNA mutation.
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Affiliation(s)
- Gus Waneka
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA and
| | - Joshua M Svendsen
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA and
| | - Justin C Havird
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA and
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22
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Bonekamp NA, Jiang M, Motori E, Garcia Villegas R, Koolmeister C, Atanassov I, Mesaros A, Park CB, Larsson NG. High levels of TFAM repress mammalian mitochondrial DNA transcription in vivo. Life Sci Alliance 2021; 4:4/11/e202101034. [PMID: 34462320 PMCID: PMC8408345 DOI: 10.26508/lsa.202101034] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 08/10/2021] [Accepted: 08/20/2021] [Indexed: 01/04/2023] Open
Abstract
Mitochondrial transcription factor A (TFAM) is compacting mitochondrial DNA (dmtDNA) into nucleoids and directly controls mtDNA copy number. Here, we show that the TFAM-to-mtDNA ratio is critical for maintaining normal mtDNA expression in different mouse tissues. Moderately increased TFAM protein levels increase mtDNA copy number but a normal TFAM-to-mtDNA ratio is maintained resulting in unaltered mtDNA expression and normal whole animal metabolism. Mice ubiquitously expressing very high TFAM levels develop pathology leading to deficient oxidative phosphorylation (OXPHOS) and early postnatal lethality. The TFAM-to-mtDNA ratio varies widely between tissues in these mice and is very high in skeletal muscle leading to strong repression of mtDNA expression and OXPHOS deficiency. In the heart, increased mtDNA copy number results in a near normal TFAM-to-mtDNA ratio and maintained OXPHOS capacity. In liver, induction of LONP1 protease and mitochondrial RNA polymerase expression counteracts the silencing effect of high TFAM levels. TFAM thus acts as a general repressor of mtDNA expression and this effect can be counterbalanced by tissue-specific expression of regulatory factors.
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Affiliation(s)
- Nina A Bonekamp
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Min Jiang
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany.,Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Growth Regulation and Transformation Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China
| | - Elisa Motori
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | | | - Camilla Koolmeister
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ilian Atanassov
- Proteomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Andrea Mesaros
- Phenotyping Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany .,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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23
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Rechkoblit O, Johnson RE, Gupta YK, Prakash L, Prakash S, Aggarwal AK. Structural basis of DNA synthesis opposite 8-oxoguanine by human PrimPol primase-polymerase. Nat Commun 2021; 12:4020. [PMID: 34188055 PMCID: PMC8241999 DOI: 10.1038/s41467-021-24317-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 06/14/2021] [Indexed: 11/30/2022] Open
Abstract
PrimPol is a human DNA polymerase-primase that localizes to mitochondria and nucleus and bypasses the major oxidative lesion 7,8-dihydro-8-oxoguanine (oxoG) via translesion synthesis, in mostly error-free manner. We present structures of PrimPol insertion complexes with a DNA template-primer and correct dCTP or erroneous dATP opposite the lesion, as well as extension complexes with C or A as a 3′−terminal primer base. We show that during the insertion of C and extension from it, the active site is unperturbed, reflecting the readiness of PrimPol to accommodate oxoG(anti). The misinsertion of A opposite oxoG(syn) also does not alter the active site, and is likely less favorable due to lower thermodynamic stability of the oxoG(syn)•A base-pair. During the extension step, oxoG(syn) induces an opening of its base-pair with A or misalignment of the 3′-A primer terminus. Together, the structures show how PrimPol accurately synthesizes DNA opposite oxidatively damaged DNA in human cells. The human DNA primase and DNA polymerase PrimPol replicates through the major oxidative DNA damage lesion 7,8-dihydro-8-oxoguanine (oxoG) via translesion synthesis in a mostly error-free manner thus suppressing oxoG-induced mutagenesis in mitochondria and the nucleus. Here, the authors present crystal structures of PrimPol in complex with an oxoG lesion in different contexts that provide mechanistic insights into how PrimPol performs predominantly accurate synthesis on oxidative-damaged DNAs in human cells.
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Affiliation(s)
- Olga Rechkoblit
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Robert E Johnson
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Yogesh K Gupta
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Greehey Children's Cancer Research Institute & Department of Biochemistry and Structural Biology, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Louise Prakash
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Satya Prakash
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Aneel K Aggarwal
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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24
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Zakirova EG, Muzyka VV, Mazunin IO, Orishchenko KE. Natural and Artificial Mechanisms of Mitochondrial Genome Elimination. Life (Basel) 2021; 11:life11020076. [PMID: 33498399 PMCID: PMC7909434 DOI: 10.3390/life11020076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 01/11/2023] Open
Abstract
The generally accepted theory of the genetic drift of mitochondrial alleles during mammalian ontogenesis is based on the presence of a selective bottleneck in the female germline. However, there is a variety of different theories on the pathways of genetic regulation of mitochondrial DNA (mtDNA) dynamics in oogenesis and adult somatic cells. The current review summarizes present knowledge on the natural mechanisms of mitochondrial genome elimination during mammalian development. We also discuss the variety of existing and developing methodologies for artificial manipulation of the mtDNA heteroplasmy level. Understanding of the basics of mtDNA dynamics will shed the light on the pathogenesis and potential therapies of human diseases associated with mitochondrial dysfunction.
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Affiliation(s)
- Elvira G. Zakirova
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.G.Z.); (V.V.M.)
| | - Vladimir V. Muzyka
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.G.Z.); (V.V.M.)
- Department of Genetic Technologies, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Ilya O. Mazunin
- Skolkovo Institute of Science and Technology, 143026 Skolkovo, Russia;
| | - Konstantin E. Orishchenko
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.G.Z.); (V.V.M.)
- Department of Genetic Technologies, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
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25
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Fontana GA, Gahlon HL. Mechanisms of replication and repair in mitochondrial DNA deletion formation. Nucleic Acids Res 2020; 48:11244-11258. [PMID: 33021629 PMCID: PMC7672454 DOI: 10.1093/nar/gkaa804] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/07/2020] [Accepted: 09/25/2020] [Indexed: 02/06/2023] Open
Abstract
Deletions in mitochondrial DNA (mtDNA) are associated with diverse human pathologies including cancer, aging and mitochondrial disorders. Large-scale deletions span kilobases in length and the loss of these associated genes contributes to crippled oxidative phosphorylation and overall decline in mitochondrial fitness. There is not a united view for how mtDNA deletions are generated and the molecular mechanisms underlying this process are poorly understood. This review discusses the role of replication and repair in mtDNA deletion formation as well as nucleic acid motifs such as repeats, secondary structures, and DNA damage associated with deletion formation in the mitochondrial genome. We propose that while erroneous replication and repair can separately contribute to deletion formation, crosstalk between these pathways is also involved in generating deletions.
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Affiliation(s)
- Gabriele A Fontana
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Hailey L Gahlon
- To whom correspondence should be addressed. Tel: +41 44 632 3731;
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26
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Filograna R, Mennuni M, Alsina D, Larsson NG. Mitochondrial DNA copy number in human disease: the more the better? FEBS Lett 2020; 595:976-1002. [PMID: 33314045 PMCID: PMC8247411 DOI: 10.1002/1873-3468.14021] [Citation(s) in RCA: 207] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/02/2020] [Accepted: 11/26/2020] [Indexed: 12/19/2022]
Abstract
Most of the genetic information has been lost or transferred to the nucleus during the evolution of mitochondria. Nevertheless, mitochondria have retained their own genome that is essential for oxidative phosphorylation (OXPHOS). In mammals, a gene‐dense circular mitochondrial DNA (mtDNA) of about 16.5 kb encodes 13 proteins, which constitute only 1% of the mitochondrial proteome. Mammalian mtDNA is present in thousands of copies per cell and mutations often affect only a fraction of them. Most pathogenic human mtDNA mutations are recessive and only cause OXPHOS defects if present above a certain critical threshold. However, emerging evidence strongly suggests that the proportion of mutated mtDNA copies is not the only determinant of disease but that also the absolute copy number matters. In this review, we critically discuss current knowledge of the role of mtDNA copy number regulation in various types of human diseases, including mitochondrial disorders, neurodegenerative disorders and cancer, and during ageing. We also provide an overview of new exciting therapeutic strategies to directly manipulate mtDNA to restore OXPHOS in mitochondrial diseases.
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Affiliation(s)
- Roberta Filograna
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Mara Mennuni
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - David Alsina
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Nils-Göran Larsson
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute for Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
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27
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Small-molecule inhibitors of human mitochondrial DNA transcription. Nature 2020; 588:712-716. [PMID: 33328633 DOI: 10.1038/s41586-020-03048-z] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 10/22/2020] [Indexed: 01/31/2023]
Abstract
Altered expression of mitochondrial DNA (mtDNA) occurs in ageing and a range of human pathologies (for example, inborn errors of metabolism, neurodegeneration and cancer). Here we describe first-in-class specific inhibitors of mitochondrial transcription (IMTs) that target the human mitochondrial RNA polymerase (POLRMT), which is essential for biogenesis of the oxidative phosphorylation (OXPHOS) system1-6. The IMTs efficiently impair mtDNA transcription in a reconstituted recombinant system and cause a dose-dependent inhibition of mtDNA expression and OXPHOS in cell lines. To verify the cellular target, we performed exome sequencing of mutagenized cells and identified a cluster of amino acid substitutions in POLRMT that cause resistance to IMTs. We obtained a cryo-electron microscopy (cryo-EM) structure of POLRMT bound to an IMT, which further defined the allosteric binding site near the active centre cleft of POLRMT. The growth of cancer cells and the persistence of therapy-resistant cancer stem cells has previously been reported to depend on OXPHOS7-17, and we therefore investigated whether IMTs have anti-tumour effects. Four weeks of oral treatment with an IMT is well-tolerated in mice and does not cause OXPHOS dysfunction or toxicity in normal tissues, despite inducing a strong anti-tumour response in xenografts of human cancer cells. In summary, IMTs provide a potent and specific chemical biology tool to study the role of mtDNA expression in physiology and disease.
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28
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Bonekamp NA, Peter B, Hillen HS, Felser A, Bergbrede T, Choidas A, Horn M, Unger A, Di Lucrezia R, Atanassov I, Li X, Koch U, Menninger S, Boros J, Habenberger P, Giavalisco P, Cramer P, Denzel MS, Nussbaumer P, Klebl B, Falkenberg M, Gustafsson CM, Larsson NG. Small-molecule inhibitors of human mitochondrial DNA transcription. Nature 2020. [PMID: 33328633 DOI: 10.1038/s41586-020-03048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Altered expression of mitochondrial DNA (mtDNA) occurs in ageing and a range of human pathologies (for example, inborn errors of metabolism, neurodegeneration and cancer). Here we describe first-in-class specific inhibitors of mitochondrial transcription (IMTs) that target the human mitochondrial RNA polymerase (POLRMT), which is essential for biogenesis of the oxidative phosphorylation (OXPHOS) system1-6. The IMTs efficiently impair mtDNA transcription in a reconstituted recombinant system and cause a dose-dependent inhibition of mtDNA expression and OXPHOS in cell lines. To verify the cellular target, we performed exome sequencing of mutagenized cells and identified a cluster of amino acid substitutions in POLRMT that cause resistance to IMTs. We obtained a cryo-electron microscopy (cryo-EM) structure of POLRMT bound to an IMT, which further defined the allosteric binding site near the active centre cleft of POLRMT. The growth of cancer cells and the persistence of therapy-resistant cancer stem cells has previously been reported to depend on OXPHOS7-17, and we therefore investigated whether IMTs have anti-tumour effects. Four weeks of oral treatment with an IMT is well-tolerated in mice and does not cause OXPHOS dysfunction or toxicity in normal tissues, despite inducing a strong anti-tumour response in xenografts of human cancer cells. In summary, IMTs provide a potent and specific chemical biology tool to study the role of mtDNA expression in physiology and disease.
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Affiliation(s)
- Nina A Bonekamp
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Bradley Peter
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Hauke S Hillen
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Andrea Felser
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | | | | | - Moritz Horn
- Metabolic and Genetic Regulation of Ageing, Max Planck Institute for Biology of Ageing, Cologne, Germany
- Acus Laboratories, Cologne, Germany
- JLP Health, Vienna, Austria
| | - Anke Unger
- Lead Discovery Center, Dortmund, Germany
| | | | - Ilian Atanassov
- Proteomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Xinping Li
- Proteomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Uwe Koch
- Lead Discovery Center, Dortmund, Germany
| | | | | | | | - Patrick Giavalisco
- Metabolomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Martin S Denzel
- Metabolic and Genetic Regulation of Ageing, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Bert Klebl
- Lead Discovery Center, Dortmund, Germany
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden.
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany.
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
- Max Planck Institute for Biology of Ageing-Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden.
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29
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Bao Y, Tong L, Song B, Liu G, Zhu Q, Lu X, Zhang J, Lu YF, Wen H, Tian Y, Sun Y, Zhu WG. UNG2 deacetylation confers cancer cell resistance to hydrogen peroxide-induced cytotoxicity. Free Radic Biol Med 2020; 160:403-417. [PMID: 32649985 DOI: 10.1016/j.freeradbiomed.2020.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 05/29/2020] [Accepted: 06/12/2020] [Indexed: 02/06/2023]
Abstract
Cancer therapeutics produce reactive oxygen species (ROS) that damage the cancer genome and lead to cell death. However, cancer cells can resist ROS-induced cytotoxicity and survive. We show that nuclear-localized uracil-DNA N-glycosylase isoform 2 (UNG2) has a critical role in preventing ROS-induced DNA damage and enabling cancer-cell resistance. Under physiological conditions, UNG2 is targeted for rapid degradation via an interaction with the E3 ligase UHRF1. In response to ROS, however, UNG2 protein in cancer cells exhibits a remarkably extended half-life. Upon ROS exposure, UNG2 is deacetylated at lysine 78 by histone deacetylases, which prevents the UNG2-UHRF1 interaction. Accumulated UNG2 protein can thus excise the base damaged by ROS and enable the cell to survive these otherwise toxic conditions. Consequently, combining HDAC inhibitors (to permit UNG2 degradation) with genotoxic agents (to produce cytotoxic cellular levels of ROS) leads to a robust synergistic killing effect in cancer cells in vitro. Altogether, these data support the application of a novel approach to cancer treatment based on promoting UNG2 degradation by altering its acetylation status using an HDAC inhibitor.
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Affiliation(s)
- Yantao Bao
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China; International Cancer Center, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Lili Tong
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Boyan Song
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Ge Liu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Qian Zhu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Xiaopeng Lu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Jun Zhang
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Ya-Fei Lu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - He Wen
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Yuan Tian
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China
| | - Yujie Sun
- Department of Cell Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Wei-Guo Zhu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, 518055, China; International Cancer Center, Shenzhen University School of Medicine, Shenzhen, 518055, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China; Shenzhen Bay Laboratory, Shenzhen University School of Medicine, Shenzhen, 518055, China.
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30
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Wan Y, Finkel T. The mitochondria regulation of stem cell aging. Mech Ageing Dev 2020; 191:111334. [PMID: 32818514 PMCID: PMC7541753 DOI: 10.1016/j.mad.2020.111334] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 08/09/2020] [Accepted: 08/11/2020] [Indexed: 01/07/2023]
Abstract
Mitochondrial dysfunction and stem cell exhaustion are among the nine separate hallmarks of aging. Emerging evidence however suggests that mitochondrial activity can have a profound influence on the self-renewal and function of stem cells, thus mechanistically linking mitochondrial function and stem cell decline. In this review, we discuss how accumulation of mtDNA mutations or alterations in mitochondrial dynamics, turnover, and signaling can modulate age-dependent stem cell function. Finally, we also describe how mitochondrial substrate utilization influences stem and progenitor activity. Together, this growing body of evidence suggests that modulation of mitochondrial activity might provide a strategy to slow or reverse age-dependent stem cell decline, and potentially, slow or reverse human aging.
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Affiliation(s)
- Yong Wan
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh/UPMC, USA; Aging Institute, University of Pittsburgh/UPMC, Pittsburgh, PA 15219, USA
| | - Toren Finkel
- Aging Institute, University of Pittsburgh/UPMC, Pittsburgh, PA 15219, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh/UPMC, USA.
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31
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Tasdogan A, McFadden DG, Mishra P. Mitochondrial DNA Haplotypes as Genetic Modifiers of Cancer. Trends Cancer 2020; 6:1044-1058. [PMID: 32980320 DOI: 10.1016/j.trecan.2020.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/05/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023]
Abstract
Mitochondria play an essential role in cellular metabolism, generation of reactive oxygen species (ROS), and the initiation of apoptosis. These properties enable mitochondria to be crucial integrators in the pathways of tumorigenesis. An open question is to what extent variation in the mitochondrial genome (mtDNA) contributes to the biological heterogeneity observed in human tumors. In this review, we summarize our current understanding of the role of mtDNA genetics in relation to human cancers.
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Affiliation(s)
- Alpaslan Tasdogan
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David G McFadden
- Department of Internal Medicine, Department of Biochemistry, Simmons Comprehensive Cancer Center, Division of Endocrinology, Program in Molecular Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Prashant Mishra
- Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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32
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Stewart JB, Chinnery PF. Extreme heterogeneity of human mitochondrial DNA from organelles to populations. Nat Rev Genet 2020; 22:106-118. [PMID: 32989265 DOI: 10.1038/s41576-020-00284-x] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2020] [Indexed: 02/06/2023]
Abstract
Contrary to the long-held view that most humans harbour only identical mitochondrial genomes, deep resequencing has uncovered unanticipated extreme genetic variation within mitochondrial DNA (mtDNA). Most, if not all, humans contain multiple mtDNA genotypes (heteroplasmy); specific patterns of variants accumulate in different tissues, including cancers, over time; and some variants are preferentially passed down or suppressed in the maternal germ line. These findings cast light on the origin and spread of mtDNA mutations at multiple scales, from the organelle to the human population, and challenge the conventional view that high percentages of a mutation are required before a new variant has functional consequences.
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Affiliation(s)
- James B Stewart
- Max Planck Institute for Biology of Ageing, Cologne, Germany.,Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
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33
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Saucedo LJ, Triolo RE, Segar KE. How Drosophila Can Inform the Emerging Paradigm of the Role of Antioxidants in Cancer. Mol Cancer Res 2020; 19:38-41. [PMID: 32873627 DOI: 10.1158/1541-7786.mcr-20-0172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 07/24/2020] [Accepted: 08/27/2020] [Indexed: 11/16/2022]
Abstract
Drosophila melanogaster has proven to be an effective model system in uncovering both genetic and cellular contributions to human cancer. Many elusive genes and signaling pathways that control oncogenic growth were first identified using flies. In many cases, these discoveries were not driven by a direct search for novel genes involved in cancer but rather stemmed from research programs to uncover mechanisms that control growth and development. However, the bounty of genetic tools and the shared evolution of multicellular organisms places Drosophila in a powerful position to purposefully elucidate observations seen in human cancers. In the past decade, the role of antioxidants in cancer progression has shifted dramatically. This review highlights major findings driving this change in perspective and underscores an array of existing work and resources in laboratories using Drosophila that can make significant contributions to how the redox environment affects cancer progression.
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Affiliation(s)
- Leslie J Saucedo
- Department of Biology, University of Puget Sound, Tacoma, Washington.
| | - Rosalie E Triolo
- Department of Biology, University of Puget Sound, Tacoma, Washington
| | - Kate E Segar
- Department of Biology, Brandeis University, Waltham, Massachusetts
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34
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Karakaidos P, Rampias T. Mitonuclear Interactions in the Maintenance of Mitochondrial Integrity. Life (Basel) 2020; 10:life10090173. [PMID: 32878185 PMCID: PMC7555762 DOI: 10.3390/life10090173] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 08/28/2020] [Indexed: 12/27/2022] Open
Abstract
In eukaryotic cells, mitochondria originated in an α-proteobacterial endosymbiont. Although these organelles harbor their own genome, the large majority of genes, originally encoded in the endosymbiont, were either lost or transferred to the nucleus. As a consequence, mitochondria have become semi-autonomous and most of their processes require the import of nuclear-encoded components to be functional. Therefore, the mitochondrial-specific translation has evolved to be coordinated by mitonuclear interactions to respond to the energetic demands of the cell, acquiring unique and mosaic features. However, mitochondrial-DNA-encoded genes are essential for the assembly of the respiratory chain complexes. Impaired mitochondrial function due to oxidative damage and mutations has been associated with numerous human pathologies, the aging process, and cancer. In this review, we highlight the unique features of mitochondrial protein synthesis and provide a comprehensive insight into the mitonuclear crosstalk and its co-evolution, as well as the vulnerabilities of the animal mitochondrial genome.
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35
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Fu Y, Tigano M, Sfeir A. Safeguarding mitochondrial genomes in higher eukaryotes. Nat Struct Mol Biol 2020; 27:687-695. [PMID: 32764737 DOI: 10.1038/s41594-020-0474-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 07/02/2020] [Indexed: 12/20/2022]
Abstract
Mitochondria respond to DNA damage and preserve their own genetic material in a manner distinct from that of the nucleus but that requires organized mito-nuclear communication. Failure to resolve mtDNA breaks leads to mitochondrial dysfunction and affects host cells and tissues. Here, we review the pathways that safeguard mitochondrial genomes and examine the insights gained from studies of cellular and tissue-wide responses to mtDNA damage and mito-nuclear genome incompatibility.
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Affiliation(s)
- Yi Fu
- Skirball Institute of Biomolecular Medicine, Cell Biology Department, NYU Grossman School of Medicine, New York, NY, USA
| | - Marco Tigano
- Skirball Institute of Biomolecular Medicine, Cell Biology Department, NYU Grossman School of Medicine, New York, NY, USA
| | - Agnel Sfeir
- Skirball Institute of Biomolecular Medicine, Cell Biology Department, NYU Grossman School of Medicine, New York, NY, USA.
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36
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Wu Z, Waneka G, Broz AK, King CR, Sloan DB. MSH1 is required for maintenance of the low mutation rates in plant mitochondrial and plastid genomes. Proc Natl Acad Sci U S A 2020. [PMID: 32601224 DOI: 10.1073/pnas.2001998117/suppl_file/pnas.2001998117.sd01.xlsx] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
Mitochondrial and plastid genomes in land plants exhibit some of the slowest rates of sequence evolution observed in any eukaryotic genome, suggesting an exceptional ability to prevent or correct mutations. However, the mechanisms responsible for this extreme fidelity remain unclear. We tested seven candidate genes involved in cytoplasmic DNA replication, recombination, and repair (POLIA, POLIB, MSH1, RECA3, UNG, FPG, and OGG1) for effects on mutation rates in the model angiosperm Arabidopsis thaliana by applying a highly accurate DNA sequencing technique (duplex sequencing) that can detect newly arisen mitochondrial and plastid mutations even at low heteroplasmic frequencies. We find that disrupting MSH1 (but not the other candidate genes) leads to massive increases in the frequency of point mutations and small indels and changes to the mutation spectrum in mitochondrial and plastid DNA. We also used droplet digital PCR to show transmission of de novo heteroplasmies across generations in msh1 mutants, confirming a contribution to heritable mutation rates. This dual-targeted gene is part of an enigmatic lineage within the mutS mismatch repair family that we find is also present outside of green plants in multiple eukaryotic groups (stramenopiles, alveolates, haptophytes, and cryptomonads), as well as certain bacteria and viruses. MSH1 has previously been shown to limit ectopic recombination in plant cytoplasmic genomes. Our results point to a broader role in recognition and correction of errors in plant mitochondrial and plastid DNA sequence, leading to greatly suppressed mutation rates perhaps via initiation of double-stranded breaks and repair pathways based on faithful homologous recombination.
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Affiliation(s)
- Zhiqiang Wu
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, 518120 Shenzhen, China
- Department of Biology, Colorado State University, Fort Collins, CO 80523
| | - Gus Waneka
- Department of Biology, Colorado State University, Fort Collins, CO 80523
| | - Amanda K Broz
- Department of Biology, Colorado State University, Fort Collins, CO 80523
| | - Connor R King
- Department of Biology, Colorado State University, Fort Collins, CO 80523
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO 80523
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37
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Arbeithuber B, Hester J, Cremona MA, Stoler N, Zaidi A, Higgins B, Anthony K, Chiaromonte F, Diaz FJ, Makova KD. Age-related accumulation of de novo mitochondrial mutations in mammalian oocytes and somatic tissues. PLoS Biol 2020; 18:e3000745. [PMID: 32667908 PMCID: PMC7363077 DOI: 10.1371/journal.pbio.3000745] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 05/27/2020] [Indexed: 12/21/2022] Open
Abstract
Mutations create genetic variation for other evolutionary forces to operate on and cause numerous genetic diseases. Nevertheless, how de novo mutations arise remains poorly understood. Progress in the area is hindered by the fact that error rates of conventional sequencing technologies (1 in 100 or 1,000 base pairs) are several orders of magnitude higher than de novo mutation rates (1 in 10,000,000 or 100,000,000 base pairs per generation). Moreover, previous analyses of germline de novo mutations examined pedigrees (and not germ cells) and thus were likely affected by selection. Here, we applied highly accurate duplex sequencing to detect low-frequency, de novo mutations in mitochondrial DNA (mtDNA) directly from oocytes and from somatic tissues (brain and muscle) of 36 mice from two independent pedigrees. We found mtDNA mutation frequencies 2- to 3-fold higher in 10-month-old than in 1-month-old mice, demonstrating mutation accumulation during the period of only 9 mo. Mutation frequencies and patterns differed between germline and somatic tissues and among mtDNA regions, suggestive of distinct mutagenesis mechanisms. Additionally, we discovered a more pronounced genetic drift of mitochondrial genetic variants in the germline of older versus younger mice, arguing for mtDNA turnover during oocyte meiotic arrest. Our study deciphered for the first time the intricacies of germline de novo mutagenesis using duplex sequencing directly in oocytes, which provided unprecedented resolution and minimized selection effects present in pedigree studies. Moreover, our work provides important information about the origins and accumulation of mutations with aging/maturation and has implications for delayed reproduction in modern human societies. Furthermore, the duplex sequencing method we optimized for single cells opens avenues for investigating low-frequency mutations in other studies.
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Affiliation(s)
- Barbara Arbeithuber
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - James Hester
- Department of Animal Science, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Marzia A. Cremona
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Nicholas Stoler
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Arslan Zaidi
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Bonnie Higgins
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Kate Anthony
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Francesca Chiaromonte
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
- EMbeDS, Sant’Anna School of Advanced Studies, Pisa, Italy
| | - Francisco J. Diaz
- Department of Animal Science, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Kateryna D. Makova
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
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38
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MSH1 is required for maintenance of the low mutation rates in plant mitochondrial and plastid genomes. Proc Natl Acad Sci U S A 2020; 117:16448-16455. [PMID: 32601224 DOI: 10.1073/pnas.2001998117] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial and plastid genomes in land plants exhibit some of the slowest rates of sequence evolution observed in any eukaryotic genome, suggesting an exceptional ability to prevent or correct mutations. However, the mechanisms responsible for this extreme fidelity remain unclear. We tested seven candidate genes involved in cytoplasmic DNA replication, recombination, and repair (POLIA, POLIB, MSH1, RECA3, UNG, FPG, and OGG1) for effects on mutation rates in the model angiosperm Arabidopsis thaliana by applying a highly accurate DNA sequencing technique (duplex sequencing) that can detect newly arisen mitochondrial and plastid mutations even at low heteroplasmic frequencies. We find that disrupting MSH1 (but not the other candidate genes) leads to massive increases in the frequency of point mutations and small indels and changes to the mutation spectrum in mitochondrial and plastid DNA. We also used droplet digital PCR to show transmission of de novo heteroplasmies across generations in msh1 mutants, confirming a contribution to heritable mutation rates. This dual-targeted gene is part of an enigmatic lineage within the mutS mismatch repair family that we find is also present outside of green plants in multiple eukaryotic groups (stramenopiles, alveolates, haptophytes, and cryptomonads), as well as certain bacteria and viruses. MSH1 has previously been shown to limit ectopic recombination in plant cytoplasmic genomes. Our results point to a broader role in recognition and correction of errors in plant mitochondrial and plastid DNA sequence, leading to greatly suppressed mutation rates perhaps via initiation of double-stranded breaks and repair pathways based on faithful homologous recombination.
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Zhao L, Sumberaz P. Mitochondrial DNA Damage: Prevalence, Biological Consequence, and Emerging Pathways. Chem Res Toxicol 2020; 33:2491-2502. [PMID: 32486637 DOI: 10.1021/acs.chemrestox.0c00083] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondria have a plethora of functions within a eukaryotic cell, ranging from energy production, cell signaling, and protein cofactor synthesis to various aspects of metabolism. Mitochondrial dysfunction is known to cause over 200 named disorders and has been implicated in many human diseases and aging. Mitochondria have their own genetic material, mitochondrial DNA (mtDNA), which encodes 13 protein subunits in the oxidative phosphorylation system and a full set of transfer and rRNAs. Although more than 99% of the proteins in mitochondria are nuclear DNA (nDNA)-encoded, the integrity of mtDNA is critical for mitochondrial functions, as evidenced by mitochondrial diseases sourced from mtDNA mutations and depletions and the vital role of fragmented mtDNA molecules in cell signaling pathways. Previous research has shown that mtDNA is an important target of genotoxic assaults by a variety of chemical and physical factors. This Perspective discusses the prevalence of mtDNA damage by comparing the abundance of lesions in mDNA and nDNA and summarizes current knowledge on the biological pathways to cope with mtDNA damage, including mtDNA repair, mtDNA degradation, and mitochondrial fission and fusion. Also, emerging roles of mtDNA damage in mutagenesis and immune responses are reviewed.
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Affiliation(s)
- Linlin Zhao
- Department of Chemistry and Environmental Toxicology Graduate Program, University of California, Riverside, Riverside, California 92521, United States
| | - Philip Sumberaz
- Department of Chemistry and Environmental Toxicology Graduate Program, University of California, Riverside, Riverside, California 92521, United States
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40
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Chen Z, Tian R, She Z, Cai J, Li H. Role of oxidative stress in the pathogenesis of nonalcoholic fatty liver disease. Free Radic Biol Med 2020; 152:116-141. [PMID: 32156524 DOI: 10.1016/j.freeradbiomed.2020.02.025] [Citation(s) in RCA: 569] [Impact Index Per Article: 142.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 02/20/2020] [Accepted: 02/26/2020] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease worldwide and is strongly associated with the presence of oxidative stress. Disturbances in lipid metabolism lead to hepatic lipid accumulation, which affects different reactive oxygen species (ROS) generators, including mitochondria, endoplasmic reticulum, and NADPH oxidase. Mitochondrial function adapts to NAFLD mainly through the downregulation of the electron transport chain (ETC) and the preserved or enhanced capacity of mitochondrial fatty acid oxidation, which stimulates ROS overproduction within different ETC components upstream of cytochrome c oxidase. However, non-ETC sources of ROS, in particular, fatty acid β-oxidation, appear to produce more ROS in hepatic metabolic diseases. Endoplasmic reticulum stress and NADPH oxidase alterations are also associated with NAFLD, but the degree of their contribution to oxidative stress in NAFLD remains unclear. Increased ROS generation induces changes in insulin sensitivity and in the expression and activity of key enzymes involved in lipid metabolism. Moreover, the interaction between redox signaling and innate immune signaling forms a complex network that regulates inflammatory responses. Based on the mechanistic view described above, this review summarizes the mechanisms that may account for the excessive production of ROS, the potential mechanistic roles of ROS that drive NAFLD progression, and therapeutic interventions that are related to oxidative stress.
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Affiliation(s)
- Ze Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, PR China; Institute of Model Animals of Wuhan University, Wuhan, 430072, PR China
| | - Ruifeng Tian
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, PR China; Institute of Model Animals of Wuhan University, Wuhan, 430072, PR China
| | - Zhigang She
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, PR China; Institute of Model Animals of Wuhan University, Wuhan, 430072, PR China; Basic Medical School, Wuhan University, Wuhan, 430071, PR China; Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430071, PR China
| | - Jingjing Cai
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, PR China; Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, 410013, PR China; Institute of Model Animals of Wuhan University, Wuhan, 430072, PR China
| | - Hongliang Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, PR China; Institute of Model Animals of Wuhan University, Wuhan, 430072, PR China; Basic Medical School, Wuhan University, Wuhan, 430071, PR China; Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430071, PR China.
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41
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Kim DV, Makarova AV, Miftakhova RR, Zharkov DO. Base Excision DNA Repair Deficient Cells: From Disease Models to Genotoxicity Sensors. Curr Pharm Des 2020; 25:298-312. [PMID: 31198112 DOI: 10.2174/1381612825666190319112930] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/13/2019] [Indexed: 12/29/2022]
Abstract
Base excision DNA repair (BER) is a vitally important pathway that protects the cell genome from many kinds of DNA damage, including oxidation, deamination, and hydrolysis. It involves several tightly coordinated steps, starting from damaged base excision and followed by nicking one DNA strand, incorporating an undamaged nucleotide, and DNA ligation. Deficiencies in BER are often embryonic lethal or cause morbid diseases such as cancer, neurodegeneration, or severe immune pathologies. Starting from the early 1980s, when the first mammalian cell lines lacking BER were produced by spontaneous mutagenesis, such lines have become a treasure trove of valuable information about the mechanisms of BER, often revealing unexpected connections with other cellular processes, such as antibody maturation or epigenetic demethylation. In addition, these cell lines have found an increasing use in genotoxicity testing, where they provide increased sensitivity and representativity to cell-based assay panels. In this review, we outline current knowledge about BER-deficient cell lines and their use.
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Affiliation(s)
- Daria V Kim
- Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russian Federation
| | - Alena V Makarova
- RAS Institute of Molecular Genetics, 2 Kurchatova Sq., Moscow 123182, Russian Federation
| | - Regina R Miftakhova
- Kazan Federal University, 18 Kremlevsakaya St., Kazan 420008, Russian Federation
| | - Dmitry O Zharkov
- Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russian Federation.,SB RAS Institute of Chemical Biology and Fu ndamental Medicine, 8 Lavrentieva Ave., Novosibirsk 630090, Russian Federation
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42
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Wynn E, Purfeerst E, Christensen A. Mitochondrial DNA Repair in an Arabidopsis thaliana Uracil N-Glycosylase Mutant. PLANTS (BASEL, SWITZERLAND) 2020; 9:E261. [PMID: 32085412 PMCID: PMC7076443 DOI: 10.3390/plants9020261] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/14/2020] [Accepted: 02/16/2020] [Indexed: 02/07/2023]
Abstract
Substitution rates in plant mitochondrial genes are extremely low, indicating strong selective pressure as well as efficient repair. Plant mitochondria possess base excision repair pathways; however, many repair pathways such as nucleotide excision repair and mismatch repair appear to be absent. In the absence of these pathways, many DNA lesions must be repaired by a different mechanism. To test the hypothesis that double-strand break repair (DSBR) is that mechanism, we maintained independent self-crossing lineages of plants deficient in uracil-N-glycosylase (UNG) for 11 generations to determine the repair outcomes when that pathway is missing. Surprisingly, no single nucleotide polymorphisms (SNPs) were fixed in any line in generation 11. The pattern of heteroplasmic SNPs was also unaltered through 11 generations. When the rate of cytosine deamination was increased by mitochondrial expression of the cytosine deaminase APOBEC3G, there was an increase in heteroplasmic SNPs but only in mature leaves. Clearly, DNA maintenance in reproductive meristem mitochondria is very effective in the absence of UNG while mitochondrial genomes in differentiated tissue are maintained through a different mechanism or not at all. Several genes involved in DSBR are upregulated in the absence of UNG, indicating that double-strand break repair is a general system of repair in plant mitochondria. It is important to note that the developmental stage of tissues is critically important for these types of experiments.
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Affiliation(s)
- Emily Wynn
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (E.W.); (E.P.)
- United States Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE 68933, USA
| | - Emma Purfeerst
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (E.W.); (E.P.)
- Athletics Department, Bethany Lutheran College, Mankato, MN 56001, USA
| | - Alan Christensen
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (E.W.); (E.P.)
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43
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van den Ameele J, Li AY, Ma H, Chinnery PF. Mitochondrial heteroplasmy beyond the oocyte bottleneck. Semin Cell Dev Biol 2020; 97:156-166. [DOI: 10.1016/j.semcdb.2019.10.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 09/17/2019] [Accepted: 10/01/2019] [Indexed: 12/31/2022]
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44
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Wallis CP, Scott LH, Filipovska A, Rackham O. Manipulating and elucidating mitochondrial gene expression with engineered proteins. Philos Trans R Soc Lond B Biol Sci 2019; 375:20190185. [PMID: 31787043 DOI: 10.1098/rstb.2019.0185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Many conventional, modern genome engineering tools cannot be used to study mitochondrial genetics due to the unusual structure and physiology of the mitochondrial genome. Here, we review a number of newly developed, synthetic biology-based approaches for altering levels of mutant mammalian mitochondrial DNA and mitochondrial RNAs, including transcription activator-like effector nucleases, zinc finger nucleases and engineered RNA-binding proteins. These approaches allow researchers to manipulate and visualize mitochondrial processes and may provide future therapeutics. This article is part of the theme issue 'Linking the mitochondrial genotype to phenotype: a complex endeavour'.
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Affiliation(s)
- Christopher P Wallis
- Harry Perkins Institute of Medical Research, Nedlands, Western Australia 6009, Australia.,The University of Western Australia Centre for Medical Research, Crawley, Western Australia 6009, Australia
| | - Louis H Scott
- Harry Perkins Institute of Medical Research, Nedlands, Western Australia 6009, Australia.,The University of Western Australia Centre for Medical Research, Crawley, Western Australia 6009, Australia
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, Nedlands, Western Australia 6009, Australia.,The University of Western Australia Centre for Medical Research, Crawley, Western Australia 6009, Australia.,School of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research, Nedlands, Western Australia 6009, Australia.,School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, Western Australia 6102, Australia.,Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia 6102, Australia
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45
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Billard P, Poncet DA. Replication Stress at Telomeric and Mitochondrial DNA: Common Origins and Consequences on Ageing. Int J Mol Sci 2019; 20:ijms20194959. [PMID: 31597307 PMCID: PMC6801922 DOI: 10.3390/ijms20194959] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/12/2022] Open
Abstract
Senescence is defined as a stress-induced durable cell cycle arrest. We herein revisit the origin of two of these stresses, namely mitochondrial metabolic compromise, associated with reactive oxygen species (ROS) production, and replicative senescence, activated by extreme telomere shortening. We discuss how replication stress-induced DNA damage of telomeric DNA (telDNA) and mitochondrial DNA (mtDNA) can be considered a common origin of senescence in vitro, with consequences on ageing in vivo. Unexpectedly, mtDNA and telDNA share common features indicative of a high degree of replicative stress, such as G-quadruplexes, D-loops, RNA:DNA heteroduplexes, epigenetic marks, or supercoiling. To avoid these stresses, both compartments use similar enzymatic strategies involving, for instance, endonucleases, topoisomerases, helicases, or primases. Surprisingly, many of these replication helpers are active at both telDNA and mtDNA (e.g., RNAse H1, FEN1, DNA2, RecQ helicases, Top2α, Top2β, TOP3A, DNMT1/3a/3b, SIRT1). In addition, specialized telomeric proteins, such as TERT (telomerase reverse transcriptase) and TERC (telomerase RNA component), or TIN2 (shelterin complex), shuttle from telomeres to mitochondria, and, by doing so, modulate mitochondrial metabolism and the production of ROS, in a feedback manner. Hence, mitochondria and telomeres use common weapons and cooperate to resist/prevent replication stresses, otherwise producing common consequences, namely senescence and ageing.
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Affiliation(s)
- Pauline Billard
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
| | - Delphine A Poncet
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
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46
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Mitochondria in the signaling pathways that control longevity and health span. Ageing Res Rev 2019; 54:100940. [PMID: 31415807 PMCID: PMC7479635 DOI: 10.1016/j.arr.2019.100940] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/09/2019] [Accepted: 08/06/2019] [Indexed: 12/26/2022]
Abstract
Genetic and pharmacological intervention studies have identified evolutionarily conserved and functionally interconnected networks of cellular energy homeostasis, nutrient-sensing, and genome damage response signaling pathways, as prominent regulators of longevity and health span in various species. Mitochondria are the primary sites of ATP production and are key players in several other important cellular processes. Mitochondrial dysfunction diminishes tissue and organ functional performance and is a commonly considered feature of the aging process. Here we review the evidence that through reciprocal and multilevel functional interactions, mitochondria are implicated in the lifespan modulation function of these pathways, which altogether constitute a highly dynamic and complex system that controls the aging process. An important characteristic of these pathways is their extensive crosstalk and apparent malleability to modification by non-invasive pharmacological, dietary, and lifestyle interventions, with promising effects on lifespan and health span in animal models and potentially also in humans.
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47
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Abstract
Perturbed mitochondrial bioenergetics constitute a core pillar of cancer-associated metabolic dysfunction. While mitochondrial dysfunction in cancer may result from myriad biochemical causes, a historically neglected source is that of the mitochondrial genome. Recent large-scale sequencing efforts and clinical studies have highlighted the prevalence of mutations in mitochondrial DNA (mtDNA) in human tumours and their potential roles in cancer progression. In this review we discuss the biology of the mitochondrial genome, sources of mtDNA mutations, and experimental evidence of a role for mtDNA mutations in cancer. We also propose a ‘metabolic licensing’ model for mtDNA mutation-derived dysfunction in cancer initiation and progression.
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Affiliation(s)
- Payam A Gammage
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK. .,CRUK Beatson Institute for Cancer Research, Glasgow, UK.
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48
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Chocron ES, Munkácsy E, Pickering AM. Cause or casualty: The role of mitochondrial DNA in aging and age-associated disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:285-297. [PMID: 30419337 PMCID: PMC6310633 DOI: 10.1016/j.bbadis.2018.09.035] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/20/2018] [Accepted: 09/04/2018] [Indexed: 12/19/2022]
Abstract
The mitochondrial genome (mtDNA) represents a tiny fraction of the whole genome, comprising just 16.6 kilobases encoding 37 genes involved in oxidative phosphorylation and the mitochondrial translation machinery. Despite its small size, much interest has developed in recent years regarding the role of mtDNA as a determinant of both aging and age-associated diseases. A number of studies have presented compelling evidence for key roles of mtDNA in age-related pathology, although many are correlative rather than demonstrating cause. In this review we will evaluate the evidence supporting and opposing a role for mtDNA in age-associated functional declines and diseases. We provide an overview of mtDNA biology, damage and repair as well as the influence of mitochondrial haplogroups, epigenetics and maternal inheritance in aging and longevity.
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Affiliation(s)
- E Sandra Chocron
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA
| | - Erin Munkácsy
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA
| | - Andrew M Pickering
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA; Department of Molecular Medicine, School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA.
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49
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Abstract
Cell-to-cell heterogeneity drives a range of (patho)physiologically important phenomena, such as cell fate and chemotherapeutic resistance. The role of metabolism, and particularly of mitochondria, is increasingly being recognized as an important explanatory factor in cell-to-cell heterogeneity. Most eukaryotic cells possess a population of mitochondria, in the sense that mitochondrial DNA (mtDNA) is held in multiple copies per cell, where the sequence of each molecule can vary. Hence, intra-cellular mitochondrial heterogeneity is possible, which can induce inter-cellular mitochondrial heterogeneity, and may drive aspects of cellular noise. In this review, we discuss sources of mitochondrial heterogeneity (variations between mitochondria in the same cell, and mitochondrial variations between supposedly identical cells) from both genetic and non-genetic perspectives, and mitochondrial genotype-phenotype links. We discuss the apparent homeostasis of mtDNA copy number, the observation of pervasive intra-cellular mtDNA mutation (which is termed "microheteroplasmy"), and developments in the understanding of inter-cellular mtDNA mutation ("macroheteroplasmy"). We point to the relationship between mitochondrial supercomplexes, cristal structure, pH, and cardiolipin as a potential amplifier of the mitochondrial genotype-phenotype link. We also discuss mitochondrial membrane potential and networks as sources of mitochondrial heterogeneity, and their influence upon the mitochondrial genome. Finally, we revisit the idea of mitochondrial complementation as a means of dampening mitochondrial genotype-phenotype links in light of recent experimental developments. The diverse sources of mitochondrial heterogeneity, as well as their increasingly recognized role in contributing to cellular heterogeneity, highlights the need for future single-cell mitochondrial measurements in the context of cellular noise studies.
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Affiliation(s)
- Juvid Aryaman
- Department of Mathematics, Imperial College London, London, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Iain G. Johnston
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- EPSRC Centre for the Mathematics of Precision Healthcare, Imperial College London, London, United Kingdom
| | - Nick S. Jones
- Department of Mathematics, Imperial College London, London, United Kingdom
- EPSRC Centre for the Mathematics of Precision Healthcare, Imperial College London, London, United Kingdom
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50
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Zhao L. Mitochondrial DNA degradation: A quality control measure for mitochondrial genome maintenance and stress response. Enzymes 2019; 45:311-341. [PMID: 31627882 DOI: 10.1016/bs.enz.2019.08.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mitochondria play a central role in bioenergetics, and fulfill a plethora of functions in cell signaling, programmed cell death, and biosynthesis of key protein cofactors. Mitochondria harbor their own genomic DNA, which encodes protein subunits of the electron transport chain and a full set of transfer and ribosomal RNAs. Mitochondrial DNA (mtDNA) is essential for cellular and organismal functions, and defects in mitochondrial genome maintenance have been implicated in common human diseases and mitochondrial disorders. mtDNA repair and degradation are known pathways to cope with mtDNA damage; however, molecular factors involved in this process have remained unclear. Such knowledge is fundamental to the understanding of mitochondrial genomic maintenance and pathology, because mtDNA degradation may contribute to the etiology of mtDNA depletion syndromes and to the activation of the innate immune response by fragmented mtDNA. This article reviews the current literature regarding the importance of mitochondrial DNA degradation in mtDNA maintenance and stress response, and the recent progress in uncovering molecular factors involved in mtDNA degradation. These factors include key components of the mtDNA replication machinery, such as DNA polymerase γ, helicase Twinkle, and exonuclease MGME1, as well as a major DNA-packaging protein, mitochondrial transcription factor A (TFAM).
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Affiliation(s)
- Linlin Zhao
- Department of Chemistry, University of California, Riverside, Riverside, CA, United States.
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