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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: 57] [Impact Index Per Article: 28.5] [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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2
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Stewart JB. Current progress with mammalian models of mitochondrial DNA disease. J Inherit Metab Dis 2021; 44:325-342. [PMID: 33099782 DOI: 10.1002/jimd.12324] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/19/2020] [Accepted: 10/21/2020] [Indexed: 12/16/2022]
Abstract
Mitochondrial disorders make up a large class of heritable diseases that cause a broad array of different human pathologies. They can affect many different organ systems, or display very specific tissue presentation, and can lead to illness either in childhood or later in life. While the over 1200 genes encoded in the nuclear DNA play an important role in human mitochondrial disease, it has been known for over 30 years that mutations of the mitochondria's own small, multicopy DNA chromosome (mtDNA) can lead to heritable human diseases. Unfortunately, animal mtDNA has resisted transgenic and directed genome editing technologies until quite recently. As such, animal models to aid in our understanding of these diseases, and to explore preclinical therapeutic research have been quite rare. This review will discuss the unusual properties of animal mitochondria that have hindered the generation of animal models. It will also discuss the existing mammalian models of human mtDNA disease, describe the methods employed in their generation, and will discuss recent advances in the targeting of DNA-manipulating enzymes to the mitochondria and how these may be employed to generate new models.
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Affiliation(s)
- James Bruce Stewart
- Max Planck Institute for Biology of Ageing, Cologne, Germany
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
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3
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Ishikawa K, Nakada K. Attempts to understand the mechanisms of mitochondrial diseases: The reverse genetics of mouse models for mitochondrial disease. Biochim Biophys Acta Gen Subj 2020; 1865:129835. [PMID: 33358867 DOI: 10.1016/j.bbagen.2020.129835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/25/2020] [Accepted: 12/18/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND Mitochondrial disease is a general term for a disease caused by a decline in mitochondrial function. The pathology of this disease is extremely diverse and complex, and the mechanism of its pathogenesis is still unknown. Using mouse models that develop the disease via the same processes as in humans is the easiest path to understanding the underlying mechanism. However, creating a mouse model is extremely difficult due to the lack of technologies that enable editing of mitochondrial DNA (mtDNA). SCOPE OF REVIEW This paper outlines the complex pathogenesis of mitochondrial disease, and the difficulties in producing relevant mouse models. Then, the paper provides a detailed discussion on several mice created with mutations in mtDNA. The paper also introduces the pathology of mouse models with mutations including knockouts of nuclear genes that directly affect mitochondrial function. MAJOR CONCLUSIONS Several mice with mtDNA mutations and those with nuclear DNA mutations have been established. Although these models help elucidate the pathological mechanism of mitochondrial disease, they lack sufficient diversity to enable a complete understanding. Considering the variety of factors that affect the cause and mechanism of mitochondrial disease, it is necessary to account for this background diversity in mouse models as well. GENERAL SIGNIFICANCE Mouse models are indispensable for understanding the pathological mechanism of mitochondrial disease, as well as for searching new treatments. There is a need for the creation and examination of mouse models with more diverse mutations and altered nuclear backgrounds and breeding environments.
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Affiliation(s)
- Kaori Ishikawa
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Kazuto Nakada
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
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4
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Ma H, Hayama T, Van Dyken C, Darby H, Koski A, Lee Y, Gutierrez NM, Yamada S, Li Y, Andrews M, Ahmed R, Liang D, Gonmanee T, Kang E, Nasser M, Kempton B, Brigande J, McGill TJ, Terzic A, Amato P, Mitalipov S. Deleterious mtDNA mutations are common in mature oocytes. Biol Reprod 2020; 102:607-619. [PMID: 31621839 PMCID: PMC7068114 DOI: 10.1093/biolre/ioz202] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/08/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022] Open
Abstract
Heritable mitochondrial DNA (mtDNA) mutations are common, yet only a few recurring pathogenic mtDNA variants account for the majority of known familial cases in humans. Purifying selection in the female germline is thought to be responsible for the elimination of most harmful mtDNA mutations during oogenesis. Here we show that deleterious mtDNA mutations are abundant in ovulated mature mouse oocytes and preimplantation embryos recovered from PolG mutator females but not in their live offspring. This implies that purifying selection acts not in the maternal germline per se, but during post-implantation development. We further show that oocyte mtDNA mutations can be captured and stably maintained in embryonic stem cells and then reintroduced into chimeras, thereby allowing examination of the effects of specific mutations on fetal and postnatal development.
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Affiliation(s)
- Hong Ma
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Tomonari Hayama
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Crystal Van Dyken
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Hayley Darby
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Amy Koski
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Yeonmi Lee
- Stem Cell Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil Songpa-gu, Seoul 05505, Republic of Korea
| | - Nuria Marti Gutierrez
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Satsuki Yamada
- Department of Cardiovascular Medicine, Center for Regenerative Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Ying Li
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Michael Andrews
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, 3375 S.W. Terwilliger Blvd, Portland, Oregon 97239, USA
| | - Riffat Ahmed
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Dan Liang
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Thanasup Gonmanee
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Eunju Kang
- Stem Cell Center, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil Songpa-gu, Seoul 05505, Republic of Korea
| | - Mohammed Nasser
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
| | - Beth Kempton
- Oregon Hearing Research Center, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - John Brigande
- Oregon Hearing Research Center, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Trevor J McGill
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, 3375 S.W. Terwilliger Blvd, Portland, Oregon 97239, USA
| | - Andre Terzic
- Department of Cardiovascular Medicine, Center for Regenerative Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Paula Amato
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Shoukhrat Mitalipov
- Center for Embryonic Cell and Gene Therapy, Oregon Health & Science University, 3303 S.W. Bond Avenue, Portland, Oregon 97239, USA
- Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
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5
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Al Khatib I, Shutt TE. Advances Towards Therapeutic Approaches for mtDNA Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1158:217-246. [PMID: 31452143 DOI: 10.1007/978-981-13-8367-0_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondria maintain and express their own genome, referred to as mtDNA, which is required for proper mitochondrial function. While mutations in mtDNA can cause a heterogeneous array of disease phenotypes, there is currently no cure for this collection of diseases. Here, we will cover characteristics of the mitochondrial genome important for understanding the pathology associated with mtDNA mutations, and review recent approaches that are being developed to treat and prevent mtDNA disease. First, we will discuss mitochondrial replacement therapy (MRT), where mitochondria from a healthy donor replace maternal mitochondria harbouring mutant mtDNA. In addition to ethical concerns surrounding this procedure, MRT is only applicable in cases where the mother is known or suspected to carry mtDNA mutations. Thus, there remains a need for other strategies to treat patients with mtDNA disease. To this end, we will also discuss several alternative means to reduce the amount of mutant mtDNA present in cells. Such methods, referred to as heteroplasmy shifting, have proven successful in animal models. In particular, we will focus on the approach of targeting engineered endonucleases to specifically cleave mutant mtDNA. Together, these approaches offer hope to prevent the transmission of mtDNA disease and potentially reduce the impact of mtDNA mutations.
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Affiliation(s)
- Iman Al Khatib
- Deparments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Timothy E Shutt
- Deparments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
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6
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Chen Z, Zhang F, Xu H. Human mitochondrial DNA diseases and Drosophila models. J Genet Genomics 2019; 46:201-212. [DOI: 10.1016/j.jgg.2019.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/05/2019] [Accepted: 03/25/2019] [Indexed: 01/06/2023]
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7
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Scheid AD, Beadnell TC, Welch DR. The second genome: Effects of the mitochondrial genome on cancer progression. Adv Cancer Res 2019; 142:63-105. [PMID: 30885364 DOI: 10.1016/bs.acr.2019.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The role of genetics in cancer has been recognized for centuries, but most studies elucidating genetic contributions to cancer have understandably focused on the nuclear genome. Mitochondrial contributions to cancer pathogenesis have been documented for decades, but how mitochondrial DNA (mtDNA) influences cancer progression and metastasis remains poorly understood. This lack of understanding stems from difficulty isolating the nuclear and mitochondrial genomes as experimental variables, which is critical for investigating direct mtDNA contributions to disease given extensive crosstalk exists between both genomes. Several in vitro and in vivo models have isolated mtDNA as an independent variable from the nuclear genome. This review compares and contrasts different models, their advantages and disadvantages for studying mtDNA contributions to cancer, focusing on the mitochondrial-nuclear exchange (MNX) mouse model and findings regarding tumor progression, metastasis, and other complex cancer-related phenotypes.
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Affiliation(s)
- Adam D Scheid
- Department of Cancer Biology, The University of Kansas Medical Center, and The University of Kansas Cancer Center, Kansas City, KS, United States
| | - Thomas C Beadnell
- Department of Cancer Biology, The University of Kansas Medical Center, and The University of Kansas Cancer Center, Kansas City, KS, United States
| | - Danny R Welch
- Department of Cancer Biology, The University of Kansas Medical Center, and The University of Kansas Cancer Center, Kansas City, KS, United States.
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8
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Kuszak AJ, Espey MG, Falk MJ, Holmbeck MA, Manfredi G, Shadel GS, Vernon HJ, Zolkipli-Cunningham Z. Nutritional Interventions for Mitochondrial OXPHOS Deficiencies: Mechanisms and Model Systems. ANNUAL REVIEW OF PATHOLOGY 2018; 13:163-191. [PMID: 29099651 PMCID: PMC5911915 DOI: 10.1146/annurev-pathol-020117-043644] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Multisystem metabolic disorders caused by defects in oxidative phosphorylation (OXPHOS) are severe, often lethal, conditions. Inborn errors of OXPHOS function are termed primary mitochondrial disorders (PMDs), and the use of nutritional interventions is routine in their supportive management. However, detailed mechanistic understanding and evidence for efficacy and safety of these interventions are limited. Preclinical cellular and animal model systems are important tools to investigate PMD metabolic mechanisms and therapeutic strategies. This review assesses the mechanistic rationale and experimental evidence for nutritional interventions commonly used in PMDs, including micronutrients, metabolic agents, signaling modifiers, and dietary regulation, while highlighting important knowledge gaps and impediments for randomized controlled trials. Cellular and animal model systems that recapitulate mutations and clinical manifestations of specific PMDs are evaluated for their potential in determining pathological mechanisms, elucidating therapeutic health outcomes, and investigating the value of nutritional interventions for mitochondrial disease conditions.
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Affiliation(s)
- Adam J Kuszak
- Office of Dietary Supplements, National Institutes of Health, Bethesda, Maryland 20852, USA;
| | - Michael Graham Espey
- Division of Cancer Biology, National Cancer Institute, Rockville, Maryland 20850, USA;
| | - Marni J Falk
- Department of Pediatrics, Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA;
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Marissa A Holmbeck
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06510-8023, USA;
| | - Giovanni Manfredi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10065, USA;
| | - Gerald S Shadel
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06510-8023, USA;
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06520-8023, USA;
| | - Hilary J Vernon
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA;
| | - Zarazuela Zolkipli-Cunningham
- Department of Pediatrics, Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA;
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9
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A Phenotype-Driven Approach to Generate Mouse Models with Pathogenic mtDNA Mutations Causing Mitochondrial Disease. Cell Rep 2017; 16:2980-2990. [PMID: 27626666 PMCID: PMC5039181 DOI: 10.1016/j.celrep.2016.08.037] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 07/18/2016] [Accepted: 08/11/2016] [Indexed: 01/30/2023] Open
Abstract
Mutations of mtDNA are an important cause of human disease, but few animal models exist. Because mammalian mitochondria cannot be transfected, the development of mice with pathogenic mtDNA mutations has been challenging, and the main strategy has therefore been to introduce mutations found in cell lines into mouse embryos. Here, we describe a phenotype-driven strategy that is based on detecting clonal expansion of pathogenic mtDNA mutations in colonic crypts of founder mice derived from heterozygous mtDNA mutator mice. As proof of concept, we report the generation of a mouse line transmitting a heteroplasmic pathogenic mutation in the alanine tRNA gene of mtDNA displaying typical characteristics of classic mitochondrial disease. In summary, we describe a straightforward and technically simple strategy based on mouse breeding and histology to generate animal models of mtDNA-mutation disease, which will be of great importance for studies of disease pathophysiology and preclinical treatment trials. We present a method to isolate and identify pathogenic mtDNA mutations in mice We describe a mouse with a pathogenic mutation in the mitochondrial tRNAALA gene The mice display disrupted mitochondrial translation as a result of the mutation The mice display molecular and histochemical symptoms of human mitochondrial disease
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10
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Modulating mitochondrial quality in disease transmission: towards enabling mitochondrial DNA disease carriers to have healthy children. Biochem Soc Trans 2017; 44:1091-100. [PMID: 27528757 PMCID: PMC4984448 DOI: 10.1042/bst20160095] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Indexed: 12/19/2022]
Abstract
One in 400 people has a maternally inherited mutation in mtDNA potentially causing incurable disease. In so-called heteroplasmic disease, mutant and normal mtDNA co-exist in the cells of carrier women. Disease severity depends on the proportion of inherited abnormal mtDNA molecules. Families who have had a child die of severe, maternally inherited mtDNA disease need reliable information on the risk of recurrence in future pregnancies. However, prenatal diagnosis and even estimates of risk are fraught with uncertainty because of the complex and stochastic dynamics of heteroplasmy. These complications include an mtDNA bottleneck, whereby hard-to-predict fluctuations in the proportions of mutant and normal mtDNA may arise between generations. In ‘mitochondrial replacement therapy’ (MRT), damaged mitochondria are replaced with healthy ones in early human development, using nuclear transfer. We are developing non-invasive alternatives, notably activating autophagy, a cellular quality control mechanism, in which damaged cellular components are engulfed by autophagosomes. This approach could be used in combination with MRT or with the regular management, pre-implantation genetic diagnosis (PGD). Mathematical theory, supported by recent experiments, suggests that this strategy may be fruitful in controlling heteroplasmy. Using mice that are transgenic for fluorescent LC3 (the hallmark of autophagy) we quantified autophagosomes in cleavage stage embryos. We confirmed that the autophagosome count peaks in four-cell embryos and this correlates with a drop in the mtDNA content of the whole embryo. This suggests removal by mitophagy (mitochondria-specific autophagy). We suggest that modulating heteroplasmy by activating mitophagy may be a useful complement to mitochondrial replacement therapy.
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11
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Generation of Xenomitochondrial Embryonic Stem Cells for the Production of Live Xenomitochondrial Mice. Methods Mol Biol 2015; 1351:163-73. [PMID: 26530681 DOI: 10.1007/978-1-4939-3040-1_12] [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: 02/17/2023]
Abstract
The unique features of the mitochondrial genome, such as its high copy number and lack of defined mechanisms of recombination, have hampered efforts to manipulate its sequence to create specific mutations in mouse mtDNA. As such, the generation of in vivo mouse models of mtDNA disease has proved technically challenging. This chapter describes a unique approach to create mitochondrial oxidative phosphorylation (OXPHOS) defects in mouse ES cells by transferring mtDNA from different murid species into Mus musculus domesticus ES cells using cytoplasmic hybrid ("cybrid") fusion. The resulting "xenocybrid" ES cells carry OXPHOS defects of varying severity, and can be utilized to generate live mouse models of mtDNA disease.
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12
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Torraco A, Peralta S, Iommarini L, Diaz F. Mitochondrial Diseases Part I: mouse models of OXPHOS deficiencies caused by defects in respiratory complex subunits or assembly factors. Mitochondrion 2015; 21:76-91. [PMID: 25660179 DOI: 10.1016/j.mito.2015.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/22/2014] [Accepted: 01/05/2015] [Indexed: 10/24/2022]
Abstract
Mitochondrial disorders are the most common inborn errors of metabolism affecting the oxidative phosphorylation system (OXPHOS). Because of the poor knowledge of the pathogenic mechanisms, a cure for these disorders is still unavailable and all the treatments currently in use are supportive more than curative. Therefore, in the past decade a great variety of mouse models have been developed to assess the in vivo function of several mitochondrial proteins involved in human diseases. Due to the genetic and physiological similarity to humans, mice represent reliable models to study the pathogenic mechanisms of mitochondrial disorders and are precious to test new therapeutic approaches. Here we summarize the features of several mouse models of mitochondrial diseases directly related to defects in subunits of the OXPHOS complexes or in assembly factors. We discuss how these models recapitulate many human conditions and how they have contributed to the understanding of mitochondrial function in health and disease.
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Affiliation(s)
- Alessandra Torraco
- Unit for Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Viale di San Paolo, 15-00146 Rome, Italy.
| | - Susana Peralta
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
| | - Francisca Diaz
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
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13
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Guitart T, Picchioni D, Piñeyro D, Ribas de Pouplana L. Human mitochondrial disease-like symptoms caused by a reduced tRNA aminoacylation activity in flies. Nucleic Acids Res 2013; 41:6595-608. [PMID: 23677612 PMCID: PMC3711456 DOI: 10.1093/nar/gkt402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The translation of genes encoded in the mitochondrial genome requires specific machinery that functions in the organelle. Among the many mutations linked to human disease that affect mitochondrial translation, several are localized to nuclear genes coding for mitochondrial aminoacyl-transfer RNA synthetases. The molecular significance of these mutations is poorly understood, but it is expected to be similar to that of the mutations affecting mitochondrial transfer RNAs. To better understand the molecular features of diseases caused by these mutations, and to improve their diagnosis and therapeutics, we have constructed a Drosophila melanogaster model disrupting the mitochondrial seryl-tRNA synthetase by RNA interference. At the molecular level, the knockdown generates a reduction in transfer RNA serylation, which correlates with the severity of the phenotype observed. The silencing compromises viability, longevity, motility and tissue development. At the cellular level, the knockdown alters mitochondrial morphology, biogenesis and function, and induces lactic acidosis and reactive oxygen species accumulation. We report that administration of antioxidant compounds has a palliative effect of some of these phenotypes. In conclusion, the fly model generated in this work reproduces typical characteristics of pathologies caused by mutations in the mitochondrial aminoacylation system, and can be useful to assess therapeutic approaches.
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Affiliation(s)
- Tanit Guitart
- Institute for Research in Biomedicine (IRB Barcelona), Gene Translation Laboratory, c/Baldiri Reixac 10, Barcelona, 08028, Catalonia, Spain
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Abstract
The classical Mendelian genetic perspective has failed to adequately explain the biology and genetics of common metabolic and degenerative diseases. This is because these diseases are primarily systemic bioenergetic diseases, and the most important energy genes are located in the cytoplasmic mitochondrial DNA (mtDNA). Therefore, to understand these "complex" diseases, we must investigate their bioenergetic pathophysiology and consider the genetics of the thousands of copies of maternally inherited mtDNA, the more than 1,000 nuclear DNA (nDNA) bioenergetic genes, and the epigenomic and signal transduction systems that coordinate these dispersed elements of the mitochondrial genome.
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Affiliation(s)
- Douglas C Wallace
- Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia, and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-4302, USA.
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15
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Dunn DA, Cannon MV, Irwin MH, Pinkert CA. Animal models of human mitochondrial DNA mutations. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1820:601-7. [PMID: 21854831 PMCID: PMC3249501 DOI: 10.1016/j.bbagen.2011.08.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 08/03/2011] [Accepted: 08/05/2011] [Indexed: 12/21/2022]
Abstract
BACKGROUND Mutations in mitochondrial DNA (mtDNA) cause a variety of pathologic states in human patients. Development of animal models harboring mtDNA mutations is crucial to elucidating pathways of disease and as models for preclinical assessment of therapeutic interventions. SCOPE OF REVIEW This review covers the knowledge gained through animal models of mtDNA mutations and the strategies used to produce them. Animals derived from spontaneous mtDNA mutations, somatic cell nuclear transfer (SCNT), nuclear translocation of mitochondrial genes followed by mitochondrial protein targeting (allotopic expression), mutations in mitochondrial DNA polymerase gamma, direct microinjection of exogenous mitochondria, and cytoplasmic hybrid (cybrid) embryonic stem cells (ES cells) containing exogenous mitochondria (transmitochondrial cells) are considered. MAJOR CONCLUSIONS A wide range of strategies have been developed and utilized in attempts to mimic human mtDNA mutation in animal models. Use of these animals in research studies has shed light on mechanisms of pathogenesis in mitochondrial disorders, yet methods for engineering specific mtDNA sequences are still in development. GENERAL SIGNIFICANCE Research animals containing mtDNA mutations are important for studies of the mechanisms of mitochondrial disease and are useful for the development of clinical therapies. This article is part of a Special Issue entitled Biochemistry of Mitochondria.
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Affiliation(s)
| | | | | | - Carl A. Pinkert
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849 USA
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Abstract
The small mammalian mitochondrial DNA (mtDNA) is very gene dense and encodes factors critical for oxidative phosphorylation. Mutations of mtDNA cause a variety of human mitochondrial diseases and are also heavily implicated in age-associated disease and aging. There has been considerable progress in our understanding of the role for mtDNA mutations in human pathology during the last two decades, but important mechanisms in mitochondrial genetics remain to be explained at the molecular level. In addition, mounting evidence suggests that most mtDNA mutations may be generated by replication errors and not by accumulated damage.
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Affiliation(s)
- Chan Bae Park
- Institute for Medical Sciences, Ajou University School of Medicine, Suwon 443-721, Korea
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17
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Mouse models of mitochondrial DNA defects and their relevance for human disease. EMBO Rep 2009; 10:137-43. [PMID: 19148224 DOI: 10.1038/embor.2008.242] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 11/28/2008] [Indexed: 01/08/2023] Open
Abstract
Qualitative and quantitative changes in mitochondrial DNA (mtDNA) have been shown to be common causes of inherited neurodegenerative and muscular diseases, and have also been implicated in ageing. These diseases can be caused by primary mtDNA mutations, or by defects in nuclear-encoded mtDNA maintenance proteins that cause secondary mtDNA mutagenesis or instability. Furthermore, it has been proposed that mtDNA copy number affects cellular tolerance to environmental stress. However, the mechanisms that regulate mtDNA copy number and the tissue-specific consequences of mtDNA mutations are largely unknown. As post-mitotic tissues differ greatly from proliferating cultured cells in their need for mtDNA maintenance, and as most mitochondrial diseases affect post-mitotic cell types, the mouse is an important model in which to study mtDNA defects. Here, we review recently developed mouse models, and their contribution to our knowledge of mtDNA maintenance and its role in disease.
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Torraco A, Diaz F, Vempati UD, Moraes CT. Mouse models of oxidative phosphorylation defects: powerful tools to study the pathobiology of mitochondrial diseases. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1793:171-80. [PMID: 18601959 PMCID: PMC2652735 DOI: 10.1016/j.bbamcr.2008.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/28/2008] [Accepted: 06/04/2008] [Indexed: 01/14/2023]
Abstract
Defects in the oxidative phosphorylation system (OXPHOS) are responsible for a group of extremely heterogeneous and pleiotropic pathologies commonly known as mitochondrial diseases. Although many mutations have been found to be responsible for OXPHOS defects, their pathogenetic mechanisms are still poorly understood. An important contribution to investigate the in vivo function of several mitochondrial proteins and their role in mitochondrial dysfunction, has been provided by mouse models. Thanks to their genetic and physiologic similarity to humans, mouse models represent a powerful tool to investigate the impact of pathological mutations on metabolic pathways. In this review we discuss the main mouse models of mitochondrial disease developed, focusing on the ones that directly affect the OXPHOS system.
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Affiliation(s)
- Alessandra Torraco
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Francisca Diaz
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Uma D. Vempati
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Carlos T. Moraes
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
- Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
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19
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Poulton J, Oakeshott P, Kennedy S. Difficulties and possible solutions in the genetic management of mtDNA disease in the preimplantation embryo. Curr Top Dev Biol 2007; 77:213-25. [PMID: 17222705 DOI: 10.1016/s0070-2153(06)77008-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Families who have had a child die of a severe, maternally inherited mitochondrial DNA (mtDNA) disease are usually desperate to avoid having further affected children. Here we discuss the problems of applying classical genetic management to mtDNA diseases (Poulton and Turnbull, 2000) and the biology underlying these problems. We explain why these disorders have lagged so far behind the genetics revolution. We then outline the directions in which management is likely to develop, including the use of preimplantation genetic diagnosis (PGD).
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Affiliation(s)
- J Poulton
- Nuffield Department of Obstetrics and Gynaecology, The Women's Center University of Oxford, Oxford OX3 9DU, United Kingdom
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20
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Pinkert CA, Trounce IA. Generation of Transmitochondrial Mice: Development of Xenomitochondrial Mice to Model Neurodegenerative Diseases. Methods Cell Biol 2007; 80:549-69. [PMID: 17445713 DOI: 10.1016/s0091-679x(06)80027-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Carl A Pinkert
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
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21
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Abstract
Oxidative phosphorylation (OXPHOS) is the only mammalian biochemical pathway dependent on the coordinated assembly of protein subunits encoded by both nuclear and mitochondrial DNA (mtDNA) genes. Cytoplasmic hybrid cells, cybrids, are created by introducing mtDNAs of interest into cells depleted of endogenous mtDNAs, and have been a central tool in unraveling effects of disease-linked mtDNA mutations. In this way, the nuclear genetic complement is held constant so that observed effects on OXPHOS can be linked to the introduced mtDNA. Cybrid studies have confirmed such linkage for many defined, disease-associated mutations. In general, a threshold principle is evident where OXPHOS defects are expressed when the proportion of mutant mtDNA in a heteroplasmic cell is high. Cybrids have also been used where mtDNA mutations are not known, but are suspected, and have produced some support for mtDNA involvement in more common neurodegenerative diseases. Mouse modeling of mtDNA transmission and disease has recently taken advantage of cybrid approaches. By using cultured cells as intermediate carriers of mtDNAs, ES cell cybrids have been produced in several laboratories by pretreatment of the cells with rhodamine 6G before cytoplast fusion. Both homoplasmic and heteroplasmic mice have been produced, allowing modeling of mtDNA transmission through the mouse germ line. We also briefly review and compare other transgenic approaches to modeling mtDNA dynamics, including mitochondrial injection into oocytes or zygotes, and embryonic karyoplast transfer. When breakthrough technology for mtDNA transformation arrives, cybrids will remain valuable for allowing exchange of engineered mtDNAs between cells.
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Affiliation(s)
- Ian A Trounce
- Center for Neuroscience, University of Melbourne, Victoria 3010, Australia
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22
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Takeda K, Tasai M, Iwamoto M, Akita T, Tagami T, Nirasawa K, Hanada H, Onishi A. Transmission of mitochondrial DNA in pigs and progeny derived from nuclear transfer of Meishan pig fibroblast cells. Mol Reprod Dev 2006; 73:306-12. [PMID: 16245357 DOI: 10.1002/mrd.20403] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In embryos derived by nuclear transfer (NT), fusion, or injection of donor cells with recipient oocytes caused mitochondrial heteroplasmy. Previous studies have reported varying patterns of mitochondrial DNA (mtDNA) transmission in cloned calves. Here, we examined the transmission of mtDNA from NT pigs to their progeny. NT pigs were created by microinjection of Meishan pig fetal fibroblast nuclei into enucleated oocytes (maternal Landrace background). Transmission of donor cell (Meishan) mtDNA was analyzed using 4 NT pigs and 25 of their progeny by PCR-mediated single-strand conformation polymorphism (PCR-SSCP) analysis, PCR-RFLP, and a specific PCR to detect Meishan mtDNA single nucleotide polymorphisms (SNP-PCR). In the blood and hair root of NT pigs, donor mtDNAs were not detected by PCR-SSCP and PCR-RFLP, but detected by SNP-PCR. These results indicated that donor mtDNAs comprised between 0.1% and 1% of total mtDNA. Only one of the progeny exhibited heteroplasmy with donor cell mtDNA populations, ranging from 0% to 44% in selected tissues. Additionally, other progeny of the same heteroplasmic founder pig were analyzed, and 89% (16/18) harbored donor cell mtDNA populations. The proportion of donor mtDNA was significantly higher in liver (12.9 +/- 8.3%) than in spleen (5.0 +/- 3.9%), ear (6.7 +/- 5.3%), and blood (5.8 +/- 3.7%) (P < 0.01). These results demonstrated that donor mtDNAs in NT pigs could be transmitted to progeny. Moreover, once heteroplasmy was transmitted to progeny of NT-derived pigs, it appears that the introduced mitochondrial populations become fixed and maternally-derived heteroplasmy was more readily maintained in subsequent generations.
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Affiliation(s)
- Kumiko Takeda
- Department of Animal Breeding and Reproduction, National Institute of Livestock and Grassland Science, National Agricultural Research Organization, Tsukuba, Japan.
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23
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Bass MG, Sokolova VA, Kustova ME, Grachyova EV, Kidgotko OV, Sorokin AV, Vasilyev VB. Assaying the probabilities of obtaining maternally inherited heteroplasmy as the basis for modeling OXPHOS diseases in animals. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:679-85. [PMID: 16829232 DOI: 10.1016/j.bbabio.2006.05.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2005] [Revised: 05/02/2006] [Accepted: 05/13/2006] [Indexed: 10/24/2022]
Abstract
Gross alterations in cell energy metabolism underlie manifestations of hereditary OXPHOS (oxidative phosphorylation) diseases, many of which depend on proportion of mutant mitochondrial DNA (mtDNA) in tissues. An animal model of OXPHOS disease with maternal inheritance of mitochondrial heteroplasmy might help understanding the peculiarities of abnormal mtDNA distribution and its effect on pre- and postnatal development. Previously we obtained mice that carry human mtDNA in some tissues. It co-existed with murine mtDNA (heteroplasmy) and was transmitted maternally to the progeny of animals developed from zygotes injected with human mitochondria. To analyze the probability of obtaining heteroplasmic mice we increased the number of experiments with early embryos and obtained more specimens from F1. About 33% of zygotes injected with human mtDNA developed into post-implantation embryos (7th-13th days). Lower amount of such developed into neonate mice (ca. 21%). Among post-implantation embryos and in generations F0 and F1 percentages of human mtDNA-carriers were ca. 14-16%. Such percentages are sufficient for modeling maternally inherited heteroplasmy in small animal groups. More data are needed to understand the regularities of anomalous mtDNA distribution among cells and tissues and whether heart and muscles frequently carrying human mtDNA in our experiments are particularly susceptible to heteroplasmy.
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Affiliation(s)
- Mikhail G Bass
- Department of Molecular Genetics, Institute of Experimental Medicine, 12 Pavlov Street, Saint-Petersburg 197376, Russia
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24
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Kasahara A, Ishikawa K, Yamaoka M, Ito M, Watanabe N, Akimoto M, Sato A, Nakada K, Endo H, Suda Y, Aizawa S, Hayashi JI. Generation of trans-mitochondrial mice carrying homoplasmic mtDNAs with a missense mutation in a structural gene using ES cells. Hum Mol Genet 2006; 15:871-81. [PMID: 16449238 DOI: 10.1093/hmg/ddl005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Generation of various kinds of trans-mitochondrial mice, mito-mice, each carrying mtDNAs with a different pathogenic mutation, is required for precise investigation of the pathogenesis of mitochondrial diseases. This study used two respiration-deficient mouse cell lines as donors of mtDNAs with possible pathogenic mutations. One cell line expressed 45-50% respiratory activity due to mouse mtDNAs with a T6589C missense mutation in the COI gene (T6589C mtDNA) and the other expressed 40% respiratory activity due to rat (Rattus norvegicus) mtDNAs in mouse cells. By cytoplasmic transfer of these mtDNAs to mouse ES cells, we isolated respiration-deficient ES cells. We obtained chimeric mice and generated their F(6) progeny carrying mouse T6589C mtDNAs by its female germ line transmission. They were respiration-deficient and thus could be used as models of mitochondrial diseases caused by point mutations in mtDNA structural genes. However, chimeric mice and mito-mice carrying rat mtDNAs were not obtained, suggesting that significant respiration defects or some deficits induced by rat mtDNAs in mouse ES cells prevented their differentiation to generate mice carrying rat mtDNAs.
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Affiliation(s)
- Atsuko Kasahara
- Graduate School of Life and Environmental Sciences, Institute of Biological Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
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25
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Sokolova VA, Kustova ME, Arbuzova NI, Sorokin AV, Moskaliova OS, Bass MG, Vasilyev VB. Obtaining mice that carry human mitochondrial DNA transmitted to the progeny. Mol Reprod Dev 2005; 68:299-307. [PMID: 15112322 DOI: 10.1002/mrd.20075] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To study human diseases associated with mutations in mitochondrial DNA one needs an animal model in which the distribution of abnormal mtDNA and its impact on the phenotype might be followed. We isolated human mitochondria from HepG2 cell culture and microinjected them into murine zygotes, upon which those were transplanted to the pseudopregnant mice. PCR with species-specific primers allowed detecting human mtDNA in the tissues of 7-13-day embryos. No serious alterations in the development of transmitochondrial embryos were noticed. Among various organs/tissues of the 13-day embryos, human mtDNA was detected only in the heart, skeletal muscles, and stomach, which is in line with its uneven distribution among the blastomeres of an early mouse embryo that we described previously. In four recipient females, the microinjected zygotes were allowed to develop to term, the four neonate males of their joint litter were sacrificed, and in three of them human mtDNA was detected in the heart, skeletal muscles, stomach, brain, testes, and bladder. Six females of that joint litter were grown and mated to intact males. In the progeny (F1) of one of the females two mice were carrying human mtDNA in the heart, skeletal muscles, stomach, brain, lungs, uterus, ovaries, and kidneys. The study confirms the possibility to obtain transmitochondrial mice carrying human mtDNA that is transmitted to the animals of the next generation. Our results also indicate that among the organs to which human mtDNA is distributed some are more likely to receive it than others.
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Affiliation(s)
- Vassilina A Sokolova
- Department of Molecular Genetics, Institute for Experimental Medicine, 12 Pavlov str., Saint-Petersburg, Russia
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26
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Abstract
The human mitochondrial genome is extremely small compared with the nuclear genome, and mitochondrial genetics presents unique clinical and experimental challenges. Despite the diminutive size of the mitochondrial genome, mitochondrial DNA (mtDNA) mutations are an important cause of inherited disease. Recent years have witnessed considerable progress in understanding basic mitochondrial genetics and the relationship between inherited mutations and disease phenotypes, and in identifying acquired mtDNA mutations in both ageing and cancer. However, many challenges remain, including the prevention and treatment of these diseases. This review explores the advances that have been made and the areas in which future progress is likely.
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27
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28
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McKenzie M, Trounce IA, Cassar CA, Pinkert CA. Production of homoplasmic xenomitochondrial mice. Proc Natl Acad Sci U S A 2004; 101:1685-90. [PMID: 14745024 PMCID: PMC341818 DOI: 10.1073/pnas.0303184101] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2003] [Accepted: 12/09/2003] [Indexed: 11/18/2022] Open
Abstract
The unique features of mtDNA, together with the lack of a wide range of mouse cell mtDNA mutants, have hampered the creation of mtDNA mutant mice. To overcome these barriers mitochondrial defects were created by introducing mitochondria from different mouse species into Mus musculus domesticus (Mm) mtDNA-less (rho(0)) L cells. Introduction of the closely related Mus spretus (Ms) or the more divergent Mus dunni (Md) mitochondria resulted in xenocybrids exhibiting grossly normal respiratory function, but mild metabolic deficiencies, with 2- and 2.5-fold increases in lactate production compared with controls. The transfer of this model from in vitro to in vivo studies was achieved by introducing Ms and Md mitochondria into rhodamine-6G-treated Mm mouse embryonic stem (ES) cells. The resultant xenocybrid ES cells remained pluripotent, and live-born chimerae were produced from both Ms and Md xenocybrid ES cells. Founder chimeric females (G(0)) were mated with successful germ-line transmission of Ms or Md mtDNA to homoplasmic G(1) offspring. These xenocybrid models represent the first viable transmitochondrial mice with homoplasmic replacement of endogenous mtDNA and confirm the feasibility of producing mitochondrial defects in mice by using a xenomitochondrial approach.
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Affiliation(s)
- Matthew McKenzie
- Genomic Disorders Research Centre, Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, Victoria 3065, Australia
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29
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Bayona-Bafaluy MP, Acín-Pérez R, Mullikin JC, Park JS, Moreno-Loshuertos R, Hu P, Pérez-Martos A, Fernández-Silva P, Bai Y, Enríquez JA. Revisiting the mouse mitochondrial DNA sequence. Nucleic Acids Res 2003; 31:5349-55. [PMID: 12954771 PMCID: PMC203322 DOI: 10.1093/nar/gkg739] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2003] [Revised: 07/29/2003] [Accepted: 07/29/2003] [Indexed: 11/15/2022] Open
Abstract
The existence of reliable mtDNA reference sequences for each species is of great relevance in a variety of fields, from phylogenetic and population genetics studies to pathogenetic determination of mtDNA variants in humans or in animal models of mtDNA-linked diseases. We present compelling evidence for the existence of sequencing errors on the current mouse mtDNA reference sequence. This includes the deletion of a full codon in two genes, the substitution of one amino acid on five occasions and also the involvement of tRNA and rRNA genes. The conclusions are supported by: (i) the re-sequencing of the original cell line used by Bibb and Clayton, the LA9 cell line, (ii) the sequencing of a second L-derivative clone (L929), and (iii) the comparison with 12 other mtDNA sequences from live mice, 10 of them maternally related with the mouse from which the L cells were generated. Two of the latest sequences are reported for the first time in this study (Balb/cJ and C57BL/6J). In addition, we found that both the LA9 and L929 mtDNAs also contain private clone polymorphic variants that, at least in the case of L929, promote functional impairment of the oxidative phosphorylation system. Consequently, the mtDNA of the strain used for the mouse genome project (C57BL/6J) is proposed as the new standard for the mouse mtDNA sequence.
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Affiliation(s)
- María Pilar Bayona-Bafaluy
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Miguel Servet 177, Zaragoza 50013, Spain
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30
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Liolitsa D, Hanna MG. Models of mitochondrial disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 53:429-66. [PMID: 12512349 DOI: 10.1016/s0074-7742(02)53016-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Danae Liolitsa
- Centre for Neuromuscular Disease, Institute of Neurology, Queen Square, London, WC1N 3BG, United Kingdom
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31
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Biousse V, Pardue MT, Wallace DC, Newman NJ. The eyes of mito-mouse: mouse models of mitochondrial disease. J Neuroophthalmol 2002; 22:279-85. [PMID: 12464732 DOI: 10.1097/00041327-200212000-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The recent creation of several mouse models of mitochondrial diseases has provided new insights into the understanding of human mitochondrial disorders. Whether these animals have clinical or histologic ophthalmologic abnormalities is of great interest given the high frequency of such abnormalities in humans with mitochondrial disorders. In this article, we describe the currently available mouse models for mitochondrial diseases with special emphasis on their ocular phenotype. These mouse models demonstrate multiple and varied ophthalmologic manifestations.
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Affiliation(s)
- Valérie Biousse
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, USA.
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32
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Bayona-Bafaluy MP, Fernández-Silva P, Enríquez JA. The thankless task of playing genetics with mammalian mitochondrial DNA: a 30-year review. Mitochondrion 2002; 2:3-25. [PMID: 16120305 DOI: 10.1016/s1567-7249(02)00044-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2002] [Revised: 05/22/2002] [Accepted: 06/05/2002] [Indexed: 10/27/2022]
Abstract
The advances obtained through the genetic tools available in yeast for studying the oxidative phosphorylation (OXPHOS) biogenesis and in particular the role of the mtDNA encoded genes, strongly contrast with the very limited benefits that similar approaches have generated for the study of mammalian mtDNA. Here we review the use of the genetic manipulation in mammalian mtDNA, its difficulty and the main types of mutants accumulated in the past 30 years and the information derived from them. We also point out the need for a substantial improvement in this field in order to obtain new tools for functional genetic studies and for the generation of animal models of mtDNA-linked diseases.
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Affiliation(s)
- M Pilar Bayona-Bafaluy
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Miguel Servet 177, Zaragoza 50013, Spain
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33
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Maier CM, Chan PH. Role of superoxide dismutases in oxidative damage and neurodegenerative disorders. Neuroscientist 2002; 8:323-34. [PMID: 12194501 DOI: 10.1177/107385840200800408] [Citation(s) in RCA: 209] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In recent years, oxidative stress has been implicated in a variety of degenerative processes, diseases, and syndromes. Some of these include atherosclerosis, myocardial infarction, stroke, and ischemia/reperfusion injury; chronic and acute inflammatory conditions such as wound healing; central nervous system disorders such as forms of familial amyotrophic lateral sclerosis (ALS) and glutathione peroxidase-linked adolescent seizures; Parkinson's disease and Alzheimer's dementia; and a variety of other age-related disorders. Among the various biochemical events associated with these conditions, emerging evidence suggests the formation of superoxide anion and expression/activity of its endogenous scavenger, superoxide dismutase (SOD), as a common denominator. This review summarizes the function of SOD under normal physiological conditions as well as its role in the cellular and molecular mechanisms underlying oxidative tissue damage and neurological abnormalities. Experimental evidence from laboratory animals that either overexpress (transgenics) or are deficient (knockouts) in antioxidant enzyme/protein levels and the genetic SOD mutations observed in some familial cases of ALS are also discussed.
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Affiliation(s)
- Carolina M Maier
- Department of Neurosurgery, Department of Neurology and Neurological Sciences, Program in Neurosciences, Stanford University School of Medicine, Stanford, California, USA.
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34
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Swerdlow RH. Mitochondrial DNA--related mitochondrial dysfunction in neurodegenerative diseases. Arch Pathol Lab Med 2002; 126:271-80. [PMID: 11860299 DOI: 10.5858/2002-126-0271-mdrmdi] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Mitochondrial dysfunction occurs in several late-onset neurodegenerative diseases. Determining its origin and significance may provide insight into the pathogeneses of these disorders. Regarding origin, one hypothesis proposes mitochondrial dysfunction is driven by mitochondrial DNA (mtDNA) aberration. This hypothesis is primarily supported by data from studies of cytoplasmic hybrid (cybrid) cell lines, which facilitate the study of mitochondrial genotype-phenotype relationships. In cybrid cell lines in which mtDNA from persons with certain neurodegenerative diseases is assessed, mitochondrial physiology is altered in ways that are potentially relevant to programmed cell death pathways. Connecting mtDNA-related mitochondrial dysfunction with programmed cell death underscores the crucial if not central role for these organelles in neurodegenerative pathophysiology. This review discusses the cybrid technique and summarizes cybrid data implicating mtDNA-related mitochondrial dysfunction in certain neurodegenerative diseases.
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Affiliation(s)
- Russell H Swerdlow
- Center for the Study of Neurodegenerative Diseases and the Department of Neurology, University of Virginia Health System, Charlottesville 22908, USA.
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35
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Abstract
Mutations in mitochondrial genes encoded by both mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) genes have been implicated in a wide range of neuromuscular diseases. MtDNA base substitution and rearrangement mutations generally inactivate one or more tRNA or rRNA genes and can cause myopathy, cardiomyopathy, cataracts, growth retardation, diabetes, etc. nDNA mutations can cause Leigh syndrome, cardiomyopathy, and nephropathy, due to defects in oxidative phosphorylation (OXPHOS) enzyme complexes; cartilage-hair hypoplasia (CHH) and mtDNA depletion syndrome, through defects in mitochondrial nucleic acid metabolism; and ophthalmoplegia with multiple mtDNA deletions, caused by adenine nucleotide translocator-1 (ANT1) mutations. Mouse models have been prepared that recapitulate a number of these diseases. The mtDNA 16S rRNA chloramphenicol (CAP) resistance mutation was introduced into the mouse female germline and caused cataracts and rod and cone abnormalities in chimeras and neonatal lethal myopathy and cardiomyopathy in mutant animals. A mtDNA deletion was introduced into the mouse germline and caused myopathy, cardiomyopathy, and nephropathy. Conditional inactivation of the nDNA mitochondrial transcription factor (Tfam) gene in the heart resulted in neonatal lethal cardiomyopathy, while its inactivation in the pancreatic beta-cells caused diabetes. The ATP/ADP ratio was implicated in mitochondrial diabetes through transgenic modification of the beta-cell ATP-sensitive K(+) channel (K(ATP)). Mutational inactivation of the mouse Ant1 gene resulted in myopathy, cardiomyopathy, and multiple mtDNA deletions in association with elevated reactive oxygen species (ROS) production. Inactivation of uncoupler proteins (Ucp) 1-3 revealed that mitochondrial Delta Psi regulated ROS production. The role of mitochondrial ROS toxicity in disease and aging was confirmed by inactivating glutathione peroxidase (GPx1), resulting in growth retardation, and by total and partial inactivation of Mn superoxide dismutase (MnSOD; Sod2), resulting in neonatal lethal dilated cardiomyopathy and accelerated apoptosis in aging, respectively. The importance of mitochondrial ROS in degenerative diseases and aging was confirmed by treating Sod2 -/- mice and C. elegans with catalytic antioxidant drugs.
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Affiliation(s)
- D C Wallace
- Center for Molecular Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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36
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Abstract
Mitochondrial DNA (mtDNA) encodes a mere 13 polypeptides, all with well-defined cellular functions in mitochondrial energy metabolism. It was first sequenced over two decades ago, yet our understanding of the wider physiological role of mtDNA is surprisingly sketchy. Partly, this reflects the fact that the mitochondrial gene products are essential for life; that is, most mtDNA mutations are expected to be lethal. The technical difficulty of engineering mtDNA mutations has been a major handicap in furthering our understanding of the mitochondrial genetic system. Recent developments now offer some possibilities for the genetic manipulation of mtDNA and for elucidating its contribution to human development, physiology and disease.
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Affiliation(s)
- H T Jacobs
- Institute of Medical Technology and Tampere University Hospital, FIN-33014 University of Tampere, Tampere, Finland.
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37
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Abstract
Mitochondrial DNA (mtDNA) is highly susceptible to mutation. Novel approaches such as those involving cytoplast fusion and mitochondrial microinjection are essential for gene therapy of diseases caused by these mutations, due to the non-Mendelian genetics of these diseases. In this fusion method, mtDNA in the cytoplast is transferred into mutant cells via the formation of cybrids; once inside the cell the mtDNA complement the defect correctly and safely. The genes in cloned animals are composed of nuclear DNA (nDNA) of a mature tissue and mtDNA from an oocyte. Recent advances in transmitochondrial mice depends on the microinjection of mitochondria into the oocyte. Here we present data on in vitro gene therapy using human mtDNA, cybrid formation and microinjection.
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Affiliation(s)
- Y Kagawa
- Department of Biochemistry, Jichi Medical School, Minamikawachi, Tochigi-ken, 329-0498 Japan
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38
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Schaefer AM, Taylor RW, Turnbull DM. The mitochondrial genome and mitochondrial muscle disorders. Curr Opin Pharmacol 2001; 1:288-93. [PMID: 11712753 DOI: 10.1016/s1471-4892(01)00051-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mitochondrial disorders represent a multitude of clinically heterogeneous diseases in which the genetic abnormality can involve either a mitochondrial or nuclear gene. In addition to inherited defects, somatic mitochondrial DNA mutations have been implicated in the pathogenesis of neurodegenerative disease, cancer and the ageing process. The recent emergence of the first mouse models of mitochondrial disease will provide valuable insights into disease mechanisms and aid the development of realistic therapeutic strategies.
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Affiliation(s)
- A M Schaefer
- Mitochondrial Research Group, School of Neurosciences and Psychiatry, The Medical School, University of Newcastle-upon-Tyne, UK
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39
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MESH Headings
- Aminoglycosides
- Animals
- Anti-Bacterial Agents/adverse effects
- Anti-Bacterial Agents/pharmacology
- Cardiomyopathy, Dilated/genetics
- Cataract/genetics
- Chimera
- Chloramphenicol Resistance/genetics
- DNA, Mitochondrial/genetics
- DNA, Ribosomal/genetics
- Disease Models, Animal
- Embryo Transfer
- Female
- Genes, Reporter
- Humans
- Mice
- Mice, Inbred NZB
- Mice, Transgenic/genetics
- Microinjections
- Mitochondrial Myopathies/genetics
- Phenotype
- Point Mutation
- Protein Biosynthesis/drug effects
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- Stem Cells/metabolism
- Transfection
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Affiliation(s)
- M Hirano
- Department of Neurology, Columbia-Presbyterian Medical Center, 630 West 168th Street, P&S 4-443, New York, NY 10032, USA.
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40
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Sligh JE, Levy SE, Waymire KG, Allard P, Dillehay DL, Nusinowitz S, Heckenlively JR, MacGregor GR, Wallace DC. Maternal germ-line transmission of mutant mtDNAs from embryonic stem cell-derived chimeric mice. Proc Natl Acad Sci U S A 2000; 97:14461-6. [PMID: 11106380 PMCID: PMC18941 DOI: 10.1073/pnas.250491597] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report a method for introducing mtDNA mutations into the mouse female germ line by means of embryonic stem (ES) cell cybrids. Mitochondria were recovered from the brain of a NZB mouse by fusion of synaptosomes to a mtDNA-deficient (rho degrees ) cell line. These cybrids were enucleated and the cytoplasts were electrofused to rhodamine-6G (R-6G)-treated female ES cells. The resulting ES cell cybrids permitted transmission of the NZB mtDNAs through the mouse maternal lineage for three generations. Similarly, mtDNAs from a partially respiratory-deficient chloramphenicol-resistant (CAP(R)) cell line also were introduced into female chimeric mice and were transmitted to the progeny. CAP(R) chimeric mice developed a variety of ocular abnormalities, including congenital cataracts, decreased retinal function, and hamaratomas of the optic nerve. The germ-line transmission of the CAP(R) mutation resulted in animals with growth retardation, myopathy, dilated cardiomyopathy, and perinatal or in utero lethality. Skeletal and heart muscle mitochondria of the CAP(R) mice were enlarged and atypical with inclusions. This mouse ES cell-cybrid approach now provides the means to generate a wide variety of mouse models of mitochondrial disease.
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Affiliation(s)
- J E Sligh
- Center for Molecular Medicine, Departments of Dermatology and Pathology and Division of Animal Resources, Emory University School of Medicine, 1462 Clifton Road, Atlanta, GA 30322, USA
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41
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Inoki Y, Hakamata Y, Hamamoto T, Kinouchi T, Yamazaki S, Kagawa Y, Endo H. Proteoliposomes colocalized with endogenous mitochondria in mouse fertilized egg. Biochem Biophys Res Commun 2000; 278:183-91. [PMID: 11071871 DOI: 10.1006/bbrc.2000.3765] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Colocalization of mitochondria is the first step of intermitochondrial interaction or fusion in a cell. Here, we showed colocalization between exogenous mitochondria and endogenous ones or between exogenous proteoliposomes and endogenous mitochondria in mouse fertilized eggs by confocal laser microscopy. Isolated mitochondria from mouse liver and proteoliposomes containing mitochondrial membrane were directly labeled with red fluorescent aliphatic marker, PKH26, which is incorporated into lipid membrane, and then were microinjected into fertilized mouse eggs. Exogenous mitochondria appeared to be almost colocalized with endogenous mitochondria at the 4- and 8-cell stages, when mitochondria were stained with Rhodamine 123 (green fluorescent marker). On the contrary, when liposomes consisted of soy bean phospholipid were microinjected into the eggs as a control, their localization was different from that of endogenous mitochondria. Next, the submitochondrial particles and proteoliposomes were microinjected. Both the proteoliposomes and the submitochondrial particles appeared to colocalize with endogenous mitochondria at the 4-cell stage. These results suggest the existence of a factor that makes liposomes colocalize with mitochondria. Such a proteoliposome would be useful for the development of mitochondrial gene transfer techniques.
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Affiliation(s)
- Y Inoki
- Department of Biochemistry, Jichi Medical School, Minamikawachi-machi, Kawachi-gun, Tochigi 329-0498, Japan
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42
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Chinnery PF, Turnbull DM. Mitochondrial DNA mutations in the pathogenesis of human disease. MOLECULAR MEDICINE TODAY 2000; 6:425-32. [PMID: 11074368 DOI: 10.1016/s1357-4310(00)01805-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The coding sequence for the human mitochondrial genome (mtDNA) was published in 1981. Within a decade, the first pathogenic mtDNA mutations were described in humans with sporadic and maternally inherited disease. The last ten years has seen a profusion of reports describing new pathogenic mutations associated with a diverse range of clinical phenotypes. Although we have seen great advances in our understanding of the molecular mechanisms involved in the pathogenesis of mtDNA disease, we are only just beginning to tackle some of the more difficult questions. In this review we describe recent advances in our understanding of mtDNA disease and highlight ways that this knowledge might lead to novel therapies in the future.
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Affiliation(s)
- P F Chinnery
- The Medical School, The University of Newcastle upon Tyne, NE2 4HH, Newcastle upon Tyne, UK
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43
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Fernández-Moreno MA, Bornstein B, Petit N, Garesse R. The pathophysiology of mitochondrial biogenesis: towards four decades of mitochondrial DNA research. Mol Genet Metab 2000; 71:481-95. [PMID: 11073716 DOI: 10.1006/mgme.2000.3083] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondria are with very few exceptions ubiquitous organelles in eukaryotic cells where they are essential for cell life and death. Mitochondria play a central role not only in a variety of metabolic pathways including the supply of the bulk of cellular ATP through oxidative phosphorylation (OXPHOS), but also in complex processes such as development, apoptosis, and aging. Mitochondria contain their own genome that is replicated and expressed within the organelle. It encodes 13 polypeptides all of them components of the OXPHOS system, and thus, the integrity of the mitochondrial DNA (mtDNA) is critical for cellular energy supply. In the past 12 years more than 50 point mutations and around 100 rearrangements in the mtDNA have been associated with human diseases. Also in recent years, several mutations in nuclear genes that encode structural or regulatory factors of the OXPHOS system or the mtDNA metabolism have been described. The development of increasingly powerful techniques and the use of cellular and animal models are opening new avenues in the study of mitochondrial medicine. The detailed molecular characterization of the effects produced by different mutations that cause mitochondrial cytopathies will be critical for designing rational therapeutic strategies for this group of devastating diseases.
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Affiliation(s)
- M A Fernández-Moreno
- Departamento de Bioquímica, Facultad de Medicina, Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Universidad Autónoma de Madrid, c/ Arzobispo Morcillo 4, Madrid, 28029, Spain
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McKenzie M, Trounce I. Expression of Rattus norvegicus mtDNA in Mus musculus cells results in multiple respiratory chain defects. J Biol Chem 2000; 275:31514-9. [PMID: 10908563 DOI: 10.1074/jbc.m004070200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The production of in vitro and in vivo models of mitochondrial DNA (mtDNA) defects is currently limited by a lack of characterized mouse cell mtDNA mutants that may be expected to model human mitochondrial diseases. Here we describe the creation of transmitochondrial mouse (Mus musculus) cells repopulated with mtDNA from different murid species (xenomitochondrial cybrids). The closely related Mus spretus mtDNA is readily maintained when introduced into M. musculus mtDNA-less (rho(0)) cells, and the resulting cybrids have normal oxidative phosphorylation (OXPHOS). When the more distantly related Rattus norvegicus mtDNA is transferred to the mouse nuclear background the mtDNA is replicated, transcribed, and translated efficiently. However, function of several OXPHOS complexes that depend on the coordinated assembly of nuclear and mtDNA-encoded proteins is impaired. Complex I activity in the Rattus xenocybrid was 46% of the control mean; complex III was 37%, and complex IV was 78%. These defects combined to restrict maximal respiration to 12-31% of the control and M. spretus xenocybrids, as measured polarographically using isolated cybrid mitochondria. These defects are distinct to those previously reported for human/primate xenocybrids. It should be possible to produce other mouse xenocybrid constructs with less severe OXPHOS phenotypes, to model human mtDNA diseases.
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Affiliation(s)
- M McKenzie
- Mutation Research Centre and the University of Melbourne, Department of Medicine, St. Vincent's Hospital, 41 Victoria Parade, Fitzroy 3065 Melbourne, Australia
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45
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Inoue K, Nakada K, Ogura A, Isobe K, Goto Y, Nonaka I, Hayashi JI. Generation of mice with mitochondrial dysfunction by introducing mouse mtDNA carrying a deletion into zygotes. Nat Genet 2000; 26:176-81. [PMID: 11017072 DOI: 10.1038/82826] [Citation(s) in RCA: 312] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Mice carrying mitochondrial DNA (mtDNA) with pathogenic mutations would provide a system in which to study how mutant mtDNAs are transmitted and distributed in tissues, resulting in expression of mitochondrial diseases. However, no effective procedures are available for the generation of these mice. Isolation of mouse cells without mtDNA (rho0) enabled us to trap mutant mtDNA that had accumulated in somatic tissues into rho0 cells repopulated with mtDNA (cybrids). We isolated respiration-deficient cybrids with mtDNA carrying a deletion and introduced this mtDNA into fertilized eggs. The mutant mtDNA was transmitted maternally, and its accumulation induced mitochondrial dysfunction in various tissues. Moreover, most of these mice died because of renal failure, suggesting the involvement of mtDNA mutations in the pathogeneses of new diseases.
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Affiliation(s)
- K Inoue
- Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan
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46
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Abstract
The rate of advance of our understanding of mitochondrial pathology continues to accelerate. Trends in genotype-phenotype correlations in mitochondrial DNA mutations continue to be developed; the latest of these is the association of exercise intolerance with cytochrome b mutations and onset in infancy of multisystem disorders associated with cytochrome oxidase assembly defects. New models for mitochondrial disease are being developed. Drugs, toxins and deficiency of nuclear encoded proteins that are targeted at mitochondria are now recognized as important causes of secondary mitochondrial respiratory chain deficiency.
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Affiliation(s)
- A H Schapira
- University Department of Clinical Neurosciences, Royal Free and University College School of Medicine, and Institute of Neurology, University College London, UK.
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47
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Steinborn R, Schinogl P, Zakhartchenko V, Achmann R, Schernthaner W, Stojkovic M, Wolf E, Müller M, Brem G. Mitochondrial DNA heteroplasmy in cloned cattle produced by fetal and adult cell cloning. Nat Genet 2000; 25:255-7. [PMID: 10888867 DOI: 10.1038/77000] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mammals have been cloned from adult donor cells. Here we report the first cases of mitochondrial DNA (mtDNA) heteroplasmy in adult mammalian clones generated from fetal and adult donor cells. The heteroplasmic clones included a healthy cattle equivalent of the sheep Dolly, for which a lack of heteroplasmy was reported.
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Affiliation(s)
- R Steinborn
- [1] Institute of Animal Breeding Genetics, University of Veterinary Medicine, Vienna, Austria.
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48
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Bigger B, Collombet JM, Coutelle C. Tipping the scales in favour of mitochondrial gene therapy. Gene Ther 1999; 6:1909-10. [PMID: 10637441 DOI: 10.1038/sj.gt.3301090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- B Bigger
- Cystic Fibrosis Gene Therapy Research Group, Section of Molecular Genetics, Division of Biomedical Sciences, Imperial College School of Medicine, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK.
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