1
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Mikhailov N, Hämäläinen RH. Modulating Mitochondrial DNA Heteroplasmy with Mitochondrially Targeted Endonucleases. Ann Biomed Eng 2024; 52:2627-2640. [PMID: 36001180 PMCID: PMC11329604 DOI: 10.1007/s10439-022-03051-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/09/2022] [Indexed: 11/01/2022]
Abstract
Mitochondria, mainly known as energy factories of eukaryotic cells, also exert several additional signaling and metabolic functions and are today recognized as major cellular biosynthetic and signaling hubs. Mitochondria possess their own genome (mitochondrial DNA-mtDNA), that encodes proteins essential for oxidative phosphorylation, and mutations in it are an important contributor to human disease. The mtDNA mutations often exist in heteroplasmic conditions, with both healthy and mutant versions of the mtDNA residing in patients' cells and the level of mutant mtDNA may vary between different tissues and organs and affect the clinical outcome of the disease. Thus, shifting the ratio between healthy and mutant mtDNA in patients' cells provides an intriguing therapeutic option for mtDNA diseases. In this review we describe current strategies for modulating mitochondrial heteroplasmy levels with engineered endonucleases including mitochondrially targeted TALENs and Zinc finger nucleases (ZFNs) and discuss their therapeutic potential. These gene therapy tools could in the future provide therapeutic help both for patients with mitochondrial disease as well as in preventing the transfer of pathogenic mtDNA mutations from a mother to her offspring.
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Affiliation(s)
- Nikita Mikhailov
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Riikka H Hämäläinen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211, Kuopio, Finland.
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2
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Moraes CT. Tools for editing the mammalian mitochondrial genome. Hum Mol Genet 2024; 33:R92-R99. [PMID: 38779768 DOI: 10.1093/hmg/ddae037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/28/2024] [Accepted: 03/03/2024] [Indexed: 05/25/2024] Open
Abstract
The manipulation of animal mitochondrial genomes has long been a challenge due to the lack of an effective transformation method. With the discovery of specific gene editing enzymes, designed to target pathogenic mitochondrial DNA mutations (often heteroplasmic), the selective removal or modification of mutant variants has become a reality. Because mitochondria cannot efficiently import RNAs, CRISPR has not been the first choice for editing mitochondrial genes. However, the last few years witnessed an explosion in novel and optimized non-CRISPR approaches to promote double-strand breaks or base-edit of mtDNA in vivo. Engineered forms of specific nucleases and cytidine/adenine deaminases form the basis for these techniques. I will review the newest developments that constitute the current toolbox for animal mtDNA gene editing in vivo, bringing these approaches not only to the exploration of mitochondrial function, but also closer to clinical use.
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Affiliation(s)
- Carlos T Moraes
- Miller School of Medicine, University of Miami, 1600 NW 10th Ave, room 7044, Miami, FL 33136, United States
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3
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Eghbalsaied S, Lawler C, Petersen B, Hajiyev RA, Bischoff SR, Frankenberg S. CRISPR/Cas9-mediated base editors and their prospects for mitochondrial genome engineering. Gene Ther 2024; 31:209-223. [PMID: 38177342 DOI: 10.1038/s41434-023-00434-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 01/06/2024]
Abstract
Base editors are a type of double-stranded break (DSB)-free gene editing technology that has opened up new possibilities for precise manipulation of mitochondrial DNA (mtDNA). This includes cytosine and adenosine base editors and more recently guanosine base editors. Because of having low off-target and indel rates, there is a growing interest in developing and evolving this research field. Here, we provide a detailed update on DNA base editors. While base editing has widely been used for nuclear genome engineering, the growing interest in applying this technology to mitochondrial DNA has been faced with several challenges. While Cas9 protein has been shown to enter mitochondria, use of smaller Cas proteins, such as Cas12a, has higher import efficiency. However, sgRNA transfer into mitochondria is the most challenging step. sgRNA structure and ratio of Cas protein to sgRNA are both important factors for efficient sgRNA entry into mitochondria. In conclusion, while there are still several challenges to be addressed, ongoing research in this field holds the potential for new treatments and therapies for mitochondrial disorders.
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Affiliation(s)
- Shahin Eghbalsaied
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.
- Department of Animal Science, Isfahan Branch, Islamic Azad University (IAU), Isfahan, Iran.
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany.
| | - Clancy Lawler
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Björn Petersen
- Department of Biotechnology, Institute of Farm Animal Genetics, Friedrich-Loeffler-Institute (FLI), Mariensee, Germany
- eGenesis, 2706 HWY E, 53572, Mount Horeb, WI, USA
| | - Raul A Hajiyev
- Department of Genome Engineering, NovoHelix, Miami, FL, USA
- Department of Computer Science, Kent State University, Kent, OH, USA
| | - Steve R Bischoff
- Department of Genome Engineering, NovoHelix, Miami, FL, USA
- Foundry for Genome Engineering & Reproductive Medicine (FGERM), Miami, FL, USA
| | - Stephen Frankenberg
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.
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4
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Phua QH, Ng SY, Soh BS. Mitochondria: A Potential Rejuvenation Tool against Aging. Aging Dis 2024; 15:503-516. [PMID: 37815912 PMCID: PMC10917551 DOI: 10.14336/ad.2023.0712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/12/2023] [Indexed: 10/12/2023] Open
Abstract
Aging is a complex physiological process encompassing both physical and cognitive decline over time. This intricate process is governed by a multitude of hallmarks and pathways, which collectively contribute to the emergence of numerous age-related diseases. In response to the remarkable increase in human life expectancy, there has been a substantial rise in research focusing on the development of anti-aging therapies and pharmacological interventions. Mitochondrial dysfunction, a critical factor in the aging process, significantly impacts overall cellular health. In this extensive review, we will explore the contemporary landscape of anti-aging strategies, placing particular emphasis on the promising potential of mitotherapy as a ground-breaking approach to counteract the aging process. Moreover, we will investigate the successful application of mitochondrial transplantation in both animal models and clinical trials, emphasizing its translational potential. Finally, we will discuss the inherent challenges and future possibilities of mitotherapy within the realm of aging research and intervention.
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Affiliation(s)
- Qian Hua Phua
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Proteos, Singapore.
- Department of Biological Sciences, National University of Singapore, Singapore.
| | - Shi Yan Ng
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Proteos, Singapore.
- National University of Singapore, Yong Loo Lin School of Medicine (Department of Physiology), Singapore.
- National Neuroscience Institute, Singapore.
| | - Boon-Seng Soh
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Proteos, Singapore.
- Department of Biological Sciences, National University of Singapore, Singapore.
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5
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Del Dotto V, Musiani F, Baracca A, Solaini G. Variants in Human ATP Synthase Mitochondrial Genes: Biochemical Dysfunctions, Associated Diseases, and Therapies. Int J Mol Sci 2024; 25:2239. [PMID: 38396915 PMCID: PMC10889682 DOI: 10.3390/ijms25042239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Mitochondrial ATP synthase (Complex V) catalyzes the last step of oxidative phosphorylation and provides most of the energy (ATP) required by human cells. The mitochondrial genes MT-ATP6 and MT-ATP8 encode two subunits of the multi-subunit Complex V. Since the discovery of the first MT-ATP6 variant in the year 1990 as the cause of Neuropathy, Ataxia, and Retinitis Pigmentosa (NARP) syndrome, a large and continuously increasing number of inborn variants in the MT-ATP6 and MT-ATP8 genes have been identified as pathogenic. Variants in these genes correlate with various clinical phenotypes, which include several neurodegenerative and multisystemic disorders. In the present review, we report the pathogenic variants in mitochondrial ATP synthase genes and highlight the molecular mechanisms underlying ATP synthase deficiency that promote biochemical dysfunctions. We discuss the possible structural changes induced by the most common variants found in patients by considering the recent cryo-electron microscopy structure of human ATP synthase. Finally, we provide the state-of-the-art of all therapeutic proposals reported in the literature, including drug interventions targeting mitochondrial dysfunctions, allotopic gene expression- and nuclease-based strategies, and discuss their potential translation into clinical trials.
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Affiliation(s)
- Valentina Del Dotto
- Laboratory of Biochemistry and Mitochondrial Pathophysiology, Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy; (V.D.D.); (G.S.)
| | - Francesco Musiani
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40127 Bologna, Italy;
| | - Alessandra Baracca
- Laboratory of Biochemistry and Mitochondrial Pathophysiology, Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy; (V.D.D.); (G.S.)
| | - Giancarlo Solaini
- Laboratory of Biochemistry and Mitochondrial Pathophysiology, Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy; (V.D.D.); (G.S.)
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6
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Zhu C, Hao Z, Liu D. Reshaping the Landscape of the Genome: Toolkits for Precise DNA Methylation Manipulation and Beyond. JACS AU 2024; 4:40-57. [PMID: 38274248 PMCID: PMC10806789 DOI: 10.1021/jacsau.3c00671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/26/2023] [Accepted: 12/01/2023] [Indexed: 01/27/2024]
Abstract
DNA methylation plays a pivotal role in various biological processes and is highly related to multiple diseases. The exact functions of DNA methylation are still puzzling due to its uneven distribution, dynamic conversion, and complex interactions with other substances. Current methods such as chemical- and enzyme-based sequencing techniques have enabled us to pinpoint DNA methylation at single-base resolution, which necessitated the manipulation of DNA methylation at comparable resolution to precisely illustrate the correlations and causal relationships between the functions of DNA methylation and its spatiotemporal patterns. Here a perspective on the past, recent process, and future of precise DNA methylation tools is provided. Specifically, genome-wide and site-specific manipulation of DNA methylation methods is discussed, with an emphasis on their principles, limitations, applications, and future developmental directions.
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Affiliation(s)
- Chenyou Zhu
- Engineering
Research Center of Advanced Rare Earth Materials, Ministry of Education,
Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Ziyang Hao
- School
of Pharmaceutical Sciences, Capital Medical
University, Beijing, 100069, PR China
| | - Dongsheng Liu
- Engineering
Research Center of Advanced Rare Earth Materials, Ministry of Education,
Department of Chemistry, Tsinghua University, Beijing 100084, China
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7
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Gao Y, Guo L, Wang F, Wang Y, Li P, Zhang D. Development of mitochondrial gene-editing strategies and their potential applications in mitochondrial hereditary diseases: a review. Cytotherapy 2024; 26:11-24. [PMID: 37930294 DOI: 10.1016/j.jcyt.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 11/07/2023]
Abstract
Mitochondrial DNA (mtDNA) is a critical genome contained within the mitochondria of eukaryotic cells, with many copies present in each mitochondrion. Mutations in mtDNA often are inherited and can lead to severe health problems, including various inherited diseases and premature aging. The lack of efficient repair mechanisms and the susceptibility of mtDNA to damage exacerbate the threat to human health. Heteroplasmy, the presence of different mtDNA genotypes within a single cell, increases the complexity of these diseases and requires an effective editing method for correction. Recently, gene-editing techniques, including programmable nucleases such as restriction endonuclease, zinc finger nuclease, transcription activator-like effector nuclease, clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated 9 and base editors, have provided new tools for editing mtDNA in mammalian cells. Base editors are particularly promising because of their high efficiency and precision in correcting mtDNA mutations. In this review, we discuss the application of these techniques in mitochondrial gene editing and their limitations. We also explore the potential of base editors for mtDNA modification and discuss the opportunities and challenges associated with their application in mitochondrial gene editing. In conclusion, this review highlights the advancements, limitations and opportunities in current mitochondrial gene-editing technologies and approaches. Our insights aim to stimulate the development of new editing strategies that can ultimately alleviate the adverse effects of mitochondrial hereditary diseases.
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Affiliation(s)
- Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Linlin Guo
- The Affiliated Cardiovascular Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Fei Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yin Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.
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8
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Zhou Y, Jin Y, Wu T, Wang Y, Dong Y, Chen P, Hu C, Pan N, Ye C, Shen L, Lin M, Fang T, Wu R. New insights on mitochondrial heteroplasmy observed in ovarian diseases. J Adv Res 2023:S2090-1232(23)00372-7. [PMID: 38061426 DOI: 10.1016/j.jare.2023.11.033] [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: 09/14/2023] [Revised: 10/26/2023] [Accepted: 11/29/2023] [Indexed: 01/01/2024] Open
Abstract
BACKGROUND The reportedly high mutation rate of mitochondrial DNA (mtDNA) may be attributed to the absence of histone protection and complete repair mechanisms. Mitochondrial heteroplasmy refers to the coexistence of wild-type and mutant mtDNA. Most healthy individuals carry a low point mutation load (<1 %) in their mtDNA, typically without any discernible phenotypic effects. However, as it exceeds a certain threshold, it may cause the onset of various diseases. Since the ovary is a highly energy-intensive organ, it relies heavily on mitochondrial function. Mitochondrial heteroplasmy can potentially contribute to a variety of significant ovarian disorders. AIM OF REVIEW In this review, we have elucidated the close relationship between mtDNA heteroplasmy and ovarian diseases, and summarized novel avenues and strategies for the potential treatment of these ovarian diseases. KEY SCIENTIFIC CONCEPTS OF REVIEW Mitochondrial heteroplasmy can potentially contribute to a variety of significant ovarian disorders, including polycystic ovary syndrome, premature ovarian insufficiency, and endometriosis. Current strategies related to mitochondrial heteroplasmy are untargeted and have low bioavailability. Nanoparticle delivery systems loaded with mitochondrial modulators, mitochondrial replacement/transplantation therapy, and mitochondria-targeted gene editing therapy may offer promising paths towards potentially more effective treatments for these diseases, despite ongoing challenges.
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Affiliation(s)
- Yong Zhou
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China; Women's Reproductive Health Key Laboratory of Zhejiang Province, People's Republic of China
| | - Yang Jin
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Tianyu Wu
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Yinfeng Wang
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Yuanhang Dong
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Pei Chen
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Changchang Hu
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Ningping Pan
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Chaoshuang Ye
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Li Shen
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Mengyan Lin
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Tao Fang
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China
| | - Ruijin Wu
- Women's Hospital, Zhejiang University School of Medicine, No. 1 Xueshi Road, Hangzhou, Zhejiang 310006, People's Republic of China; Women's Reproductive Health Key Laboratory of Zhejiang Province, People's Republic of China; Zhejiang Provincial Clinical Research Center for Obstetrics and Gynecology, People's Republic of China.
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9
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Shoop WK, Lape J, Trum M, Powell A, Sevigny E, Mischler A, Bacman SR, Fontanesi F, Smith J, Jantz D, Gorsuch CL, Moraes CT. Efficient elimination of MELAS-associated m.3243G mutant mitochondrial DNA by an engineered mitoARCUS nuclease. Nat Metab 2023; 5:2169-2183. [PMID: 38036771 PMCID: PMC10730414 DOI: 10.1038/s42255-023-00932-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 10/16/2023] [Indexed: 12/02/2023]
Abstract
Nuclease-mediated editing of heteroplasmic mitochondrial DNA (mtDNA) seeks to preferentially cleave and eliminate mutant mtDNA, leaving wild-type genomes to repopulate the cell and shift mtDNA heteroplasmy. Various technologies are available, but many suffer from limitations based on size and/or specificity. The use of ARCUS nucleases, derived from naturally occurring I-CreI, avoids these pitfalls due to their small size, single-component protein structure and high specificity resulting from a robust protein-engineering process. Here we describe the development of a mitochondrial-targeted ARCUS (mitoARCUS) nuclease designed to target one of the most common pathogenic mtDNA mutations, m.3243A>G. mitoARCUS robustly eliminated mutant mtDNA without cutting wild-type mtDNA, allowing for shifts in heteroplasmy and concomitant improvements in mitochondrial protein steady-state levels and respiration. In vivo efficacy was demonstrated using a m.3243A>G xenograft mouse model with mitoARCUS delivered systemically by adeno-associated virus. Together, these data support the development of mitoARCUS as an in vivo gene-editing therapeutic for m.3243A>G-associated diseases.
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Affiliation(s)
- Wendy K Shoop
- Precision BioSciences, Durham, NC, USA
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | | | | | | | | | - Sandra R Bacman
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Flavia Fontanesi
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | | | | | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA.
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10
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Liu M, Ji W, Zhao X, Liu X, Hu JF, Cui J. Therapeutic potential of engineering the mitochondrial genome. Biochim Biophys Acta Mol Basis Dis 2023:166804. [PMID: 37429560 DOI: 10.1016/j.bbadis.2023.166804] [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: 04/20/2023] [Revised: 06/29/2023] [Accepted: 07/05/2023] [Indexed: 07/12/2023]
Abstract
Mitochondrial diseases are a group of clinical disorders caused by mutations in the genes encoded by either the nuclear or the mitochondrial genome involved in mitochondrial oxidative phosphorylation. Disorders become evident when mitochondrial dysfunction reaches a cell-specific threshold. Similarly, the severity of disorders is related to the degree of gene mutation. Clinical treatments for mitochondrial diseases mainly rely on symptomatic management. Theoretically, replacing or repairing dysfunctional mitochondria to acquire and preserve normal physiological functions should be effective. Significant advances have been made in gene therapies, including mitochondrial replacement therapy, mitochondrial genome manipulation, nuclease programming, mitochondrial DNA editing, and mitochondrial RNA interference. In this paper, we review the recent progress in these technologies by focusing on advancements that overcome limitations.
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Affiliation(s)
- Mengmeng Liu
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Wei Ji
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Xin Zhao
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Xiaoliang Liu
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin 130061, China
| | - Ji-Fan Hu
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin 130061, China; Stanford University Medical School, VA Palo Alto Health Care System, Palo Alto, CA 94304, USA.
| | - Jiuwei Cui
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Cancer Center, First Hospital of Jilin University, Changchun, Jilin 130061, China.
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11
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Phan HTL, Lee H, Kim K. Trends and prospects in mitochondrial genome editing. Exp Mol Med 2023:10.1038/s12276-023-00973-7. [PMID: 37121968 DOI: 10.1038/s12276-023-00973-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/20/2022] [Accepted: 01/05/2023] [Indexed: 05/02/2023] Open
Abstract
Mitochondria are of fundamental importance in programmed cell death, cellular metabolism, and intracellular calcium concentration modulation, and inheritable mitochondrial disorders via mitochondrial DNA (mtDNA) mutation cause several diseases in various organs and systems. Nevertheless, mtDNA editing, which plays an essential role in the treatment of mitochondrial disorders, still faces several challenges. Recently, programmable editing tools for mtDNA base editing, such as cytosine base editors derived from DddA (DdCBEs), transcription activator-like effector (TALE)-linked deaminase (TALED), and zinc finger deaminase (ZFD), have emerged with considerable potential for correcting pathogenic mtDNA variants. In this review, we depict recent advances in the field, including structural biology and repair mechanisms, and discuss the prospects of using base editing tools on mtDNA to broaden insight into their medical applicability for treating mitochondrial diseases.
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Affiliation(s)
- Hong Thi Lam Phan
- Department of Physiology, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Hyunji Lee
- Laboratory Animal Resource and Research Center, Korea Research Institute of Bioscience and Biotechnology, 28116, Cheongju, Republic of Korea.
- School of Medicine, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Kyoungmi Kim
- Department of Physiology, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
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12
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Otsuka T, Matsui H. Fish Models for Exploring Mitochondrial Dysfunction Affecting Neurodegenerative Disorders. Int J Mol Sci 2023; 24:ijms24087079. [PMID: 37108237 PMCID: PMC10138900 DOI: 10.3390/ijms24087079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Neurodegenerative disorders are characterized by the progressive loss of neuronal structure or function, resulting in memory loss and movement disorders. Although the detailed pathogenic mechanism has not been elucidated, it is thought to be related to the loss of mitochondrial function in the process of aging. Animal models that mimic the pathology of a disease are essential for understanding human diseases. In recent years, small fish have become ideal vertebrate models for human disease due to their high genetic and histological homology to humans, ease of in vivo imaging, and ease of genetic manipulation. In this review, we first outline the impact of mitochondrial dysfunction on the progression of neurodegenerative diseases. Then, we highlight the advantages of small fish as model organisms, and present examples of previous studies regarding mitochondria-related neuronal disorders. Lastly, we discuss the applicability of the turquoise killifish, a unique model for aging research, as a model for neurodegenerative diseases. Small fish models are expected to advance our understanding of the mitochondrial function in vivo, the pathogenesis of neurodegenerative diseases, and be important tools for developing therapies to treat diseases.
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Affiliation(s)
- Takayoshi Otsuka
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Hideaki Matsui
- Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
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13
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Karaa A, Klopstock T. Clinical trials in mitochondrial diseases. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:229-250. [PMID: 36813315 DOI: 10.1016/b978-0-12-821751-1.00002-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Primary mitochondrial diseases are some of the most common and complex inherited inborn errors of metabolism. Their molecular and phenotypic diversity has led to difficulties in finding disease-modifying therapies and clinical trial efforts have been slow due to multiple significant challenges. Lack of robust natural history data, difficulties in finding specific biomarkers, absence of well-validated outcome measures, and small patient numbers have made clinical trial design and conduct difficult. Encouragingly, new interest in treating mitochondrial dysfunction in common diseases and regulatory incentives to develop therapies for rare conditions have led to significant interest and efforts to develop drugs for primary mitochondrial diseases. Here, we review past and present clinical trials and future strategies of drug development in primary mitochondrial diseases.
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Affiliation(s)
- Amel Karaa
- Mitochondrial Disease Program, Division of Medical Genetics and Metabolism, Massachusetts General Hospital, Boston, MA, United States; Department of Pediatrics, Harvard Medical School, Boston, MA, United States.
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, Ludwig-Maximilians-Universität (LMU) München, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; German Network for mitochondrial disorders (mitoNET), Munich, Germany
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14
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Nash PA, Minczuk M. Manipulation of Murine Mitochondrial DNA Heteroplasmy with mtZFNs. Methods Mol Biol 2023; 2615:329-344. [PMID: 36807802 DOI: 10.1007/978-1-0716-2922-2_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Mouse models of mitochondrial DNA mutations hold promise in the development and optimization of mitochondrial gene therapy technology and for gathering pre-clinical data prior to human trials. Their suitability for this purpose stems from the high similarity of human and murine mitochondrial genomes and the increasing availability of rationally designed AAV vectors capable of selectively transducing murine tissues. Our laboratory routinely optimizes mitochondrially targeted zinc finger nucleases (mtZFNs), the compactness of which makes them highly suitable for downstream AAV-based in vivo mitochondrial gene therapy. This chapter discusses the necessary precautions for the robust and precise genotyping of the murine mitochondrial genome as well as the optimization of mtZFNs intended for subsequent use in vivo.
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Affiliation(s)
- Pavel A Nash
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
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15
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Soldatov VO, Kubekina MV, Skorkina MY, Belykh AE, Egorova TV, Korokin MV, Pokrovskiy MV, Deykin AV, Angelova PR. Current advances in gene therapy of mitochondrial diseases. J Transl Med 2022; 20:562. [PMID: 36471396 PMCID: PMC9724384 DOI: 10.1186/s12967-022-03685-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/04/2022] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial diseases (MD) are a heterogeneous group of multisystem disorders involving metabolic errors. MD are characterized by extremely heterogeneous symptoms, ranging from organ-specific to multisystem dysfunction with different clinical courses. Most primary MD are autosomal recessive but maternal inheritance (from mtDNA), autosomal dominant, and X-linked inheritance is also known. Mitochondria are unique energy-generating cellular organelles designed to survive and contain their own unique genetic coding material, a circular mtDNA fragment of approximately 16,000 base pairs. The mitochondrial genetic system incorporates closely interacting bi-genomic factors encoded by the nuclear and mitochondrial genomes. Understanding the dynamics of mitochondrial genetics supporting mitochondrial biogenesis is especially important for the development of strategies for the treatment of rare and difficult-to-diagnose diseases. Gene therapy is one of the methods for correcting mitochondrial disorders.
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Affiliation(s)
- Vladislav O. Soldatov
- grid.4886.20000 0001 2192 9124Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia ,grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia ,grid.445984.00000 0001 2224 0652Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia ,grid.465470.4Laboratory of Biophysics of Cell Membranes under Critical State, V.A. Negovsky Scientific Research Institute of General Reanimatology, Russian Academy of Sciences, Moscow, Russia
| | - Marina V. Kubekina
- grid.4886.20000 0001 2192 9124Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Marina Yu. Skorkina
- grid.445984.00000 0001 2224 0652Department of Biochemistry, Belgorod State National Research University, Belgorod, Russia ,grid.445984.00000 0001 2224 0652Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia
| | - Andrei E. Belykh
- grid.419305.a0000 0001 1943 2944Dioscuri Centre for Metabolic Diseases, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Tatiana V. Egorova
- grid.4886.20000 0001 2192 9124Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail V. Korokin
- grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Mikhail V. Pokrovskiy
- grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Alexey V. Deykin
- grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia ,grid.445984.00000 0001 2224 0652Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia
| | - Plamena R. Angelova
- grid.83440.3b0000000121901201Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
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16
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Willis JCW, Silva-Pinheiro P, Widdup L, Minczuk M, Liu DR. Compact zinc finger base editors that edit mitochondrial or nuclear DNA in vitro and in vivo. Nat Commun 2022; 13:7204. [PMID: 36418298 PMCID: PMC9684478 DOI: 10.1038/s41467-022-34784-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022] Open
Abstract
DddA-derived cytosine base editors (DdCBEs) use programmable DNA-binding TALE repeat arrays, rather than CRISPR proteins, a split double-stranded DNA cytidine deaminase (DddA), and a uracil glycosylase inhibitor to mediate C•G-to-T•A editing in nuclear and organelle DNA. Here we report the development of zinc finger DdCBEs (ZF-DdCBEs) and the improvement of their editing performance through engineering their architectures, defining improved ZF scaffolds, and installing DddA activity-enhancing mutations. We engineer variants with improved DNA specificity by integrating four strategies to reduce off-target editing. We use optimized ZF-DdCBEs to install or correct disease-associated mutations in mitochondria and in the nucleus. Leveraging their small size, we use a single AAV9 to deliver into heart, liver, and skeletal muscle in post-natal mice ZF-DdCBEs that efficiently install disease-associated mutations. While off-target editing of ZF-DdCBEs is likely too high for therapeutic applications, these findings demonstrate a compact, all-protein base editing research tool for precise editing of organelle or nuclear DNA without double-strand DNA breaks.
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Affiliation(s)
- Julian C W Willis
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | | | - Lily Widdup
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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17
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Lee S, Lee H, Baek G, Namgung E, Park JM, Kim S, Hong S, Kim JS. Enhanced mitochondrial DNA editing in mice using nuclear-exported TALE-linked deaminases and nucleases. Genome Biol 2022; 23:211. [PMID: 36224582 PMCID: PMC9554978 DOI: 10.1186/s13059-022-02782-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 10/03/2022] [Indexed: 11/10/2022] Open
Abstract
We present two methods for enhancing the efficiency of mitochondrial DNA (mtDNA) editing in mice with DddA-derived cytosine base editors (DdCBEs). First, we fused DdCBEs to a nuclear export signal (DdCBE-NES) to avoid off-target C-to-T conversions in the nuclear genome and improve editing efficiency in mtDNA. Second, mtDNA-targeted TALENs (mitoTALENs) are co-injected into mouse embryos to cleave unedited mtDNA. We generated a mouse model with the m.G12918A mutation in the MT-ND5 gene, associated with mitochondrial genetic disorders in humans. The mutant mice show hunched appearances, damaged mitochondria in kidney and brown adipose tissues, and hippocampal atrophy, resulting in premature death.
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Affiliation(s)
- Seonghyun Lee
- Center for Genome Engineering, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Hyunji Lee
- Laboratory Animal Resource and Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, 28116, Republic of Korea.,School of Medicine, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Gayoung Baek
- Center for Genome Engineering, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Eunji Namgung
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Joo Min Park
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Sanghun Kim
- Laboratory Animal Resource and Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, 28116, Republic of Korea.,College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Seongho Hong
- Laboratory Animal Resource and Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, 28116, Republic of Korea
| | - Jin-Soo Kim
- Center for Genome Engineering, Institute for Basic Science, Daejeon, 34126, Republic of Korea.
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18
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Tani H, Ishikawa K, Tamashiro H, Ogasawara E, Yasukawa T, Matsuda S, Shimizu A, Kang D, Hayashi JI, Wei FY, Nakada K. Aberrant RNA processing contributes to the pathogenesis of mitochondrial diseases in trans-mitochondrial mouse model carrying mitochondrial tRNALeu(UUR) with a pathogenic A2748G mutation. Nucleic Acids Res 2022; 50:9382-9396. [PMID: 35998911 PMCID: PMC9458463 DOI: 10.1093/nar/gkac699] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 07/13/2022] [Accepted: 08/04/2022] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial tRNAs are indispensable for the intra-mitochondrial translation of genes related to respiratory subunits, and mutations in mitochondrial tRNA genes have been identified in various disease patients. However, the molecular mechanism underlying pathogenesis remains unclear due to the lack of animal models. Here, we established a mouse model, designated 'mito-mice tRNALeu(UUR)2748', that carries a pathogenic A2748G mutation in the tRNALeu(UUR) gene of mitochondrial DNA (mtDNA). The A2748G mutation is orthologous to the human A3302G mutation found in patients with mitochondrial diseases and diabetes. A2748G mtDNA was maternally inherited, equally distributed among tissues in individual mice, and its abundance did not change with age. At the molecular level, A2748G mutation is associated with aberrant processing of precursor mRNA containing tRNALeu(UUR) and mt-ND1, leading to a marked decrease in the steady-levels of ND1 protein and Complex I activity in tissues. Mito-mice tRNALeu(UUR)2748 with ≥50% A2748G mtDNA exhibited age-dependent metabolic defects including hyperglycemia, insulin insensitivity, and hepatic steatosis, resembling symptoms of patients carrying the A3302G mutation. This work demonstrates a valuable mouse model with an inheritable pathological A2748G mutation in mt-tRNALeu(UUR) that shows metabolic syndrome-like phenotypes at high heteroplasmy level. Furthermore, our findings provide molecular basis for understanding A3302G mutation-mediated mitochondrial disorders.
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Affiliation(s)
- Haruna Tani
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan,Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Kaori Ishikawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan,Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Hiroaki Tamashiro
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Emi Ogasawara
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Takehiro Yasukawa
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan,Department of Pathology and Oncology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Shigeru Matsuda
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Miyagi 980-8575, Japan,Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Akinori Shimizu
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Jonan-ku, Fukuoka, Fukuoka 814-0180, Japan
| | - Dongchon Kang
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan,Kashiigaoka Rehabilitation Hospital, Higashi-ku, Fukuoka, Fukuoka 813-0002, Japan
| | - Jun-Ichi Hayashi
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Fan-Yan Wei
- Department of Modomics Biology and Medicine, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Kazuto Nakada
- To whom correspondence should be addressed. Tel: +81 29 853 6694; Fax: +81 29 853 6614;
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19
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Sun J, Lo HTJ, Fan L, Yiu TL, Shakoor A, Li G, Lee WYW, Sun D. High-efficiency quantitative control of mitochondrial transfer based on droplet microfluidics and its application on muscle regeneration. SCIENCE ADVANCES 2022; 8:eabp9245. [PMID: 35977014 PMCID: PMC9385153 DOI: 10.1126/sciadv.abp9245] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 07/01/2022] [Indexed: 05/31/2023]
Abstract
Mitochondrial transfer is a spontaneous process to restore damaged cells in various pathological conditions. The transfer of mitochondria to cell therapy products before their administration can enhance therapeutic outcomes. However, the low efficiency of previously reported methods limits their clinical application. Here, we developed a droplet microfluidics-based mitochondrial transfer technique that can achieve high-efficiency and high-throughput quantitative mitochondrial transfer to single cells. Because mitochondria are essential for muscles, myoblast cells and a muscle injury model were used as a proof-of-concept model to evaluate the proposed technique. In vitro and in vivo experiments demonstrated that C2C12 cells with 31 transferred mitochondria had significant improvements in cellular functions compared to those with 0, 8, and 14 transferred mitochondria and also had better therapeutic effects on muscle regeneration. The proposed technique can considerably promote the clinical application of mitochondrial transfer, with optimized cell function improvements, for the cell therapy of mitochondria-related diseases.
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Affiliation(s)
- Jiayu Sun
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Hiu Tung Jessica Lo
- Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- Stem Cells and Regenerative Medicine Laboratory, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
| | - Lei Fan
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Tsz Lam Yiu
- Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- Stem Cells and Regenerative Medicine Laboratory, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
| | - Adnan Shakoor
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Gang Li
- Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- Stem Cells and Regenerative Medicine Laboratory, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
| | - Wayne Y. W. Lee
- Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- Stem Cells and Regenerative Medicine Laboratory, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
- SH Ho Scoliosis Research Laboratory, Joint Scoliosis Research Centre of the Chinese University of Hong Kong and Nanjing University, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Dong Sun
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Centre for Robotics and Automation, City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
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20
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Gene Therapy for Mitochondrial Diseases: Current Status and Future Perspective. Pharmaceutics 2022; 14:pharmaceutics14061287. [PMID: 35745859 PMCID: PMC9231068 DOI: 10.3390/pharmaceutics14061287] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/09/2022] [Accepted: 06/15/2022] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial diseases (MDs) are a group of severe genetic disorders caused by mutations in the nuclear or mitochondrial genome encoding proteins involved in the oxidative phosphorylation (OXPHOS) system. MDs have a wide range of symptoms, ranging from organ-specific to multisystemic dysfunctions, with different clinical outcomes. The lack of natural history information, the limits of currently available preclinical models, and the wide range of phenotypic presentations seen in MD patients have all hampered the development of effective therapies. The growing number of pre-clinical and clinical trials over the last decade has shown that gene therapy is a viable precision medicine option for treating MD. However, several obstacles must be overcome, including vector design, targeted tissue tropism and efficient delivery, transgene expression, and immunotoxicity. This manuscript offers a comprehensive overview of the state of the art of gene therapy in MD, addressing the main challenges, the most feasible solutions, and the future perspectives of the field.
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21
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Yamada Y, Ishizuka S, Arai M, Maruyama M, Harashima H. Recent advances in delivering RNA-based therapeutics to mitochondria. Expert Opin Biol Ther 2022; 22:1209-1219. [PMID: 35543589 DOI: 10.1080/14712598.2022.2070427] [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: 11/04/2022]
Abstract
INTRODUCTION After the emergence of lipid nanoparticles (LNP) containing therapeutic mRNA as vaccines for use against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the clinical usefulness of nucleic acid-encapsulated LNPs is now a fact. In addition to the nucleus and cytoplasm, mitochondria, which have their own genome, are a site where nucleic acids function in the cell. Gene therapies targeting mitochondria are expected to pave the way for the next generation of therapies. AREAS COVERED Methods for delivering nucleic acids to mitochondria are needed in order to realize such innovative therapies. However, only a few reports on delivery systems targeting mitochondria have appeared. In this review, we summarize the current state of research on RNA-based therapeutics targeted to mitochondria, with emphasis on mitochondrial RNA delivery therapies and on therapies that involve the use of mitochondrial genome editing devices. EXPERT OPINION We hope that this review article will focus our attention to this area of research, stimulate more interest in this field of research, and lead to the development of mitochondria-targeted nucleic acid medicine. It has the potential to become a major weapon against urgent and unknown diseases, including SARS-CoV-2 infections.
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Affiliation(s)
- Yuma Yamada
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.,Fusion Oriented Research for Disruptive Science and Technology (FOREST) Program, Japan Science and Technology Agency (JST), Japan
| | - Sen Ishizuka
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Manae Arai
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Minako Maruyama
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
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22
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Barrera-Paez JD, Moraes CT. Mitochondrial genome engineering coming-of-age. Trends Genet 2022; 38:869-880. [PMID: 35599021 PMCID: PMC9283244 DOI: 10.1016/j.tig.2022.04.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/11/2022] [Accepted: 04/27/2022] [Indexed: 12/16/2022]
Abstract
The mitochondrial genome has been difficult to manipulate because it is shielded by the organelle double membranes, preventing efficient nucleic acid entry. Moreover, mitochondrial DNA (mtDNA) recombination is not a robust system in most species. This limitation has forced investigators to rely on naturally occurring alterations to study both mitochondrial function and pathobiology. Because most pathogenic mtDNA mutations are heteroplasmic, the development of specific nucleases has allowed us to selectively eliminate mutant species. Several 'protein only' gene-editing platforms have been successfully used for this purpose. More recently, a DNA double-strand cytidine deaminase has been identified and adapted to edit mtDNA. This enzyme was also used as a component to adapt a DNA single-strand deoxyadenosine deaminase to mtDNA editing. These are major advances in our ability to precisely alter the mtDNA in animal cells.
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23
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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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24
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Yoshinaga N, Numata K. Rational Designs at the Forefront of Mitochondria-Targeted Gene Delivery: Recent Progress and Future Perspectives. ACS Biomater Sci Eng 2022; 8:348-359. [PMID: 34979085 DOI: 10.1021/acsbiomaterials.1c01114] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria play an essential role in cellular metabolism and generate energy in cells. To support these functions, several proteins are encoded in the mitochondrial DNA (mtDNA). The mutation of mtDNA causes mitochondrial dysfunction and ultimately results in a variety of inherited diseases. To date, gene delivery systems targeting mitochondria have been developed to ameliorate mtDNA mutations. However, applications of these strategies in mitochondrial gene therapy are still being explored and optimized. Thus, from this perspective, we herein highlight recent mitochondria-targeting strategies for gene therapy and discuss future directions for effective mitochondria-targeted gene delivery.
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Affiliation(s)
- Naoto Yoshinaga
- Biomacromolecule Research Team, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Keiji Numata
- Biomacromolecule Research Team, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan.,Department of Material Chemistry, Kyoto University, Kyoto 606-8501, Japan
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25
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Mitochondrial Genome Editing to Treat Human Osteoarthritis-A Narrative Review. Int J Mol Sci 2022; 23:ijms23031467. [PMID: 35163384 PMCID: PMC8835930 DOI: 10.3390/ijms23031467] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 12/27/2022] Open
Abstract
Osteoarthritis (OA) is a severe, common chronic orthopaedic disorder characterised by a degradation of the articular cartilage with an incidence that increases over years. Despite the availability of various clinical options, none can stop the irreversible progression of the disease to definitely cure OA. Various mutations have been evidenced in the mitochondrial DNA (mtDNA) of cartilage cells (chondrocytes) in OA, leading to a dysfunction of the mitochondrial oxidative phosphorylation processes that significantly contributes to OA cartilage degeneration. The mitochondrial genome, therefore, represents a central, attractive target for therapy in OA, especially using genome editing procedures. In this narrative review article, we present and discuss the current advances and breakthroughs in mitochondrial genome editing as a potential, novel treatment to overcome mtDNA-related disorders such as OA. While still in its infancy and despite a number of challenges that need to be addressed (barriers to effective and site-specific mtDNA editing and repair), such a strategy has strong value to treat human OA in the future, especially using the groundbreaking clustered regularly interspaced short palindromic repeats (CRIPSR)/CRISPR-associated 9 (CRISPR/Cas9) technology and mitochondrial transplantation approaches.
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26
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Tang JX, Pyle A, Taylor RW, Oláhová M. Interrogating Mitochondrial Biology and Disease Using CRISPR/Cas9 Gene Editing. Genes (Basel) 2021; 12:genes12101604. [PMID: 34680998 PMCID: PMC8536160 DOI: 10.3390/genes12101604] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/07/2021] [Accepted: 10/09/2021] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial disease originates from genetic changes that impact human bodily functions by disrupting the mitochondrial oxidative phosphorylation system. MitoCarta is a curated and published inventory that sheds light on the mitochondrial proteome, but the function of some mitochondrially-localised proteins remains poorly characterised. Consequently, various gene editing systems have been employed to uncover the involvement of these proteins in mitochondrial biology and disease. CRISPR/Cas9 is an efficient, versatile, and highly accurate genome editing tool that was first introduced over a decade ago and has since become an indispensable tool for targeted genetic manipulation in biological research. The broad spectrum of CRISPR/Cas9 applications serves as an attractive and tractable system to study genes and pathways that are essential for the regulation and maintenance of mitochondrial health. It has opened possibilities of generating reliable cell and animal models of human disease, and with further exploitation of the technology, large-scale genomic screenings have uncovered a wealth of fundamental mechanistic insights. In this review, we describe the applications of CRISPR/Cas9 system as a genome editing tool to uncover new insights into pathomechanisms of mitochondrial diseases and/or biological processes involved in mitochondrial function.
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Affiliation(s)
- Jia-Xin Tang
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (J.-X.T.); (A.P.); (R.W.T.)
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (J.-X.T.); (A.P.); (R.W.T.)
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (J.-X.T.); (A.P.); (R.W.T.)
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, UK
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (J.-X.T.); (A.P.); (R.W.T.)
- Correspondence:
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27
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Fu L, Luo YX, Liu Y, Liu H, Li HZ, Yu Y. Potential of Mitochondrial Genome Editing for Human Fertility Health. Front Genet 2021; 12:673951. [PMID: 34354734 PMCID: PMC8329452 DOI: 10.3389/fgene.2021.673951] [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: 02/28/2021] [Accepted: 06/28/2021] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial DNA (mtDNA) encodes vital proteins and RNAs for the normal functioning of the mitochondria. Mutations in mtDNA leading to mitochondrial dysfunction are relevant to a large spectrum of diseases, including fertility disorders. Since mtDNA undergoes rather complex processes during gametogenesis and fertilization, clarification of the changes and functions of mtDNA and its essential impact on gamete quality and fertility during this process is of great significance. Thanks to the emergence and rapid development of gene editing technology, breakthroughs have been made in mitochondrial genome editing (MGE), offering great potential for the treatment of mtDNA-related diseases. In this review, we summarize the features of mitochondria and their unique genome, emphasizing their inheritance patterns; illustrate the role of mtDNA in gametogenesis and fertilization; and discuss potential therapies based on MGE as well as the outlook in this field.
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Affiliation(s)
- Lin Fu
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology and Key Laboratory of Assisted Reproduction, Ministry of Education, Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China
| | - Yu-Xin Luo
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, China
| | - Ying Liu
- Food Inspection and Quarantine Technology Center of Shenzhen Customs District, FICS, Shenzhen, China
| | - Hui Liu
- Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Hong-Zhen Li
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology and Key Laboratory of Assisted Reproduction, Ministry of Education, Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China
| | - Yang Yu
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology and Key Laboratory of Assisted Reproduction, Ministry of Education, Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.,Stem Cell Research Center, Peking University Third Hospital, Beijing, China
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28
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Mitochondrial Heteroplasmy Shifting as a Potential Biomarker of Cancer Progression. Int J Mol Sci 2021; 22:ijms22147369. [PMID: 34298989 PMCID: PMC8304746 DOI: 10.3390/ijms22147369] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 02/07/2023] Open
Abstract
Cancer is a serious health problem with a high mortality rate worldwide. Given the relevance of mitochondria in numerous physiological and pathological mechanisms, such as adenosine triphosphate (ATP) synthesis, apoptosis, metabolism, cancer progression and drug resistance, mitochondrial genome (mtDNA) analysis has become of great interest in the study of human diseases, including cancer. To date, a high number of variants and mutations have been identified in different types of tumors, which coexist with normal alleles, a phenomenon named heteroplasmy. This mechanism is considered an intermediate state between the fixation or elimination of the acquired mutations. It is suggested that mutations, which confer adaptive advantages to tumor growth and invasion, are enriched in malignant cells. Notably, many recent studies have reported a heteroplasmy-shifting phenomenon as a potential shaper in tumor progression and treatment response, and we suggest that each cancer type also has a unique mitochondrial heteroplasmy-shifting profile. So far, a plethora of data evidencing correlations among heteroplasmy and cancer-related phenotypes are available, but still, not authentic demonstrations, and whether the heteroplasmy or the variation in mtDNA copy number (mtCNV) in cancer are cause or consequence remained unknown. Further studies are needed to support these findings and decipher their clinical implications and impact in the field of drug discovery aimed at treating human cancer.
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29
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Yang X, Jiang J, Li Z, Liang J, Xiang Y. Strategies for mitochondrial gene editing. Comput Struct Biotechnol J 2021; 19:3319-3329. [PMID: 34188780 PMCID: PMC8202187 DOI: 10.1016/j.csbj.2021.06.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/22/2022] Open
Abstract
Mitochondria, as the energy factory of cells, participate in metabolism processes and play a critical role in the maintenance of human life activities. Mitochondria belong to semi-automatic organelles, which have their own genome different from nuclear genome. Mitochondrial DNA (mtDNA) mutations can cause a series of diseases and threaten human health. However, an effective approach to edit mitochondrial DNA, though long-desired, is lacking. In recent years, gene editing technologies, represented by restriction endonucleases (RE) technology, zinc finger nuclease (ZFN) technology, transcription activator-like effector nuclease (TALEN) technology, CRISPR system and pAgo-based system have been comprehensively explored, but the application of these technologies in mitochondrial gene editing is still to be explored and optimized. The present study highlights the progress and limitations of current mitochondrial gene editing technologies and approaches, and provides insights for development of novel strategies for future attempts.
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Affiliation(s)
- Xingbo Yang
- School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Jiacheng Jiang
- School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Zongyu Li
- School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Jiayi Liang
- School of Mathematics and Statistics, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Yaozu Xiang
- School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
- Shanghai East Hospital, Tongji University, Shanghai 200092, China
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30
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Mitochondrial targeted meganuclease as a platform to eliminate mutant mtDNA in vivo. Nat Commun 2021; 12:3210. [PMID: 34050192 PMCID: PMC8163834 DOI: 10.1038/s41467-021-23561-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 04/26/2021] [Indexed: 11/24/2022] Open
Abstract
Diseases caused by heteroplasmic mitochondrial DNA mutations have no effective treatment or cure. In recent years, DNA editing enzymes were tested as tools to eliminate mutant mtDNA in heteroplasmic cells and tissues. Mitochondrial-targeted restriction endonucleases, ZFNs, and TALENs have been successful in shifting mtDNA heteroplasmy, but they all have drawbacks as gene therapy reagents, including: large size, heterodimeric nature, inability to distinguish single base changes, or low flexibility and effectiveness. Here we report the adaptation of a gene editing platform based on the I-CreI meganuclease known as ARCUS®. These mitochondrial-targeted meganucleases (mitoARCUS) have a relatively small size, are monomeric, and can recognize sequences differing by as little as one base pair. We show the development of a mitoARCUS specific for the mouse m.5024C>T mutation in the mt-tRNAAla gene and its delivery to mice intravenously using AAV9 as a vector. Liver and skeletal muscle show robust elimination of mutant mtDNA with concomitant restoration of mt-tRNAAla levels. We conclude that mitoARCUS is a potential powerful tool for the elimination of mutant mtDNA. Heteroplasmic mitochondrial DNA mutations lack effective treatments. Here the authors adapt I-CreI meganuclease to target the mitochondria and specifically-eliminate mtDNA with a m.5024C>T mutation in the mttRNA Ala gene.
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31
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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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32
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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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Pitceathly RD, Keshavan N, Rahman J, Rahman S. Moving towards clinical trials for mitochondrial diseases. J Inherit Metab Dis 2021; 44:22-41. [PMID: 32618366 PMCID: PMC8432143 DOI: 10.1002/jimd.12281] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/22/2020] [Accepted: 06/30/2020] [Indexed: 12/11/2022]
Abstract
Primary mitochondrial diseases represent some of the most common and severe inherited metabolic disorders, affecting ~1 in 4,300 live births. The clinical and molecular diversity typified by mitochondrial diseases has contributed to the lack of licensed disease-modifying therapies available. Management for the majority of patients is primarily supportive. The failure of clinical trials in mitochondrial diseases partly relates to the inefficacy of the compounds studied. However, it is also likely to be a consequence of the significant challenges faced by clinicians and researchers when designing trials for these disorders, which have historically been hampered by a lack of natural history data, biomarkers and outcome measures to detect a treatment effect. Encouragingly, over the past decade there have been significant advances in therapy development for mitochondrial diseases, with many small molecules now transitioning from preclinical to early phase human interventional studies. In this review, we present the treatments and management strategies currently available to people with mitochondrial disease. We evaluate the challenges and potential solutions to trial design and highlight the emerging pharmacological and genetic strategies that are moving from the laboratory to clinical trials for this group of disorders.
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Affiliation(s)
- Robert D.S. Pitceathly
- Department of Neuromuscular DiseasesUCL Queen Square Institute of Neurology and The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Nandaki Keshavan
- Mitochondrial Research GroupUCL Great Ormond Street Institute of Child HealthLondonUK
- Metabolic UnitGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUK
| | - Joyeeta Rahman
- Mitochondrial Research GroupUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Shamima Rahman
- Mitochondrial Research GroupUCL Great Ormond Street Institute of Child HealthLondonUK
- Metabolic UnitGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUK
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34
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He H, Lin X, Wu D, Wang J, Guo J, Green DR, Zhang H, Xu B. Enzymatic Noncovalent Synthesis for Mitochondrial Genetic Engineering of Cancer Cells. CELL REPORTS. PHYSICAL SCIENCE 2020; 1:100270. [PMID: 33511360 PMCID: PMC7839975 DOI: 10.1016/j.xcrp.2020.100270] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Since mitochondria contribute to tumorigenesis and drug resistance in cancer, mitochondrial genetic engineering promises a new direction for cancer therapy. Here, we report the use of the perimitochondrial enzymatic noncovalent synthesis (ENS) of peptides for delivering genes selectively into the mitochondria of cancer cells for mitochondrial genetic engineering. Specifically, the micelles of peptides bind to the voltage-dependent anion channel (VDAC) on mitochondria for the proteolysis by enterokinase (ENTK), generating perimitochondrial nanofibers in cancer cells. This process, facilitating selective delivery of nucleic acid or gene vectors into mitochondria of cancer cells, enables the mitochondrial transgene expression of CRISPR/Cas9, FUNDC1, p53, and fluorescent proteins. Mechanistic investigation indicates that the interaction of the peptide assemblies with the VDAC and mitochondrial membrane potential are necessary for mitochondria targeting. This local enzymatic control of intermolecular noncovalent interactions enables selective mitochondrial genetic engineering, thus providing a strategy for targeting cancer cells.
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Affiliation(s)
- Hongjian He
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Xinyi Lin
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Difei Wu
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Jiaqing Wang
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Jiaqi Guo
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
| | - Douglas R. Green
- Immunology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-3678, USA
| | - Hongwei Zhang
- School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, 179 Longwood Avenue, Boston, MA 02115, USA
| | - Bing Xu
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA
- Lead contact
- Correspondence:
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35
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Huang C, Yan S, Zhang Z. Maintaining the balance of TDP-43, mitochondria, and autophagy: a promising therapeutic strategy for neurodegenerative diseases. Transl Neurodegener 2020; 9:40. [PMID: 33126923 PMCID: PMC7597011 DOI: 10.1186/s40035-020-00219-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/14/2020] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are the energy center of cell operations and are involved in physiological functions and maintenance of metabolic balance and homeostasis in the body. Alterations of mitochondrial function are associated with a variety of degenerative and acute diseases. As mitochondria age in cells, they gradually become inefficient and potentially toxic. Acute injury can trigger the permeability of mitochondrial membranes, which can lead to apoptosis or necrosis. Transactive response DNA-binding protein 43 kDa (TDP-43) is a protein widely present in cells. It can bind to RNA, regulate a variety of RNA processes, and play a role in the formation of multi-protein/RNA complexes. Thus, the normal physiological functions of TDP-43 are particularly important for cell survival. Normal TDP-43 is located in various subcellular structures including mitochondria, mitochondrial-associated membrane, RNA particles and stress granules to regulate the endoplasmic reticulum–mitochondrial binding, mitochondrial protein translation, and mRNA transport and translation. Importantly, TDP-43 is associated with a variety of neurodegenerative diseases, including amyotrophic lateral sclerosis, frontotemporal dementia and Alzheimer's disease, which are characterized by abnormal phosphorylation, ubiquitination, lysis or nuclear depletion of TDP-43 in neurons and glial cells. Although the pathogenesis of TDP-43 proteinopathy remains unknown, the presence of pathological TDP-43 inside or outside of mitochondria and the functional involvement of TDP-43 in the regulation of mitochondrial morphology, transport, and function suggest that mitochondria are associated with TDP-43-related diseases. Autophagy is a basic physiological process that maintains the homeostasis of cells, including targeted clearance of abnormally aggregated proteins and damaged organelles in the cytoplasm; therefore, it is considered protective against neurodegenerative diseases. However, the combination of abnormal TDP-43 aggregation, mitochondrial dysfunction, and insufficient autophagy can lead to a variety of aging-related pathologies. In this review, we describe the current knowledge on the associations of mitochondria with TDP-43 and the role of autophagy in the clearance of abnormally aggregated TDP-43 and dysfunctional mitochondria. Finally, we discuss a novel approach for neurodegenerative treatment based on the knowledge.
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Affiliation(s)
- Chunhui Huang
- Institute of New Drug Research, Guangdong Province Key Laboratory of Pharmacodynamic, Constituents of Traditional Chinese Medicine and New Drug Research, College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Sen Yan
- Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, 510632, China.
| | - Zaijun Zhang
- Institute of New Drug Research, Guangdong Province Key Laboratory of Pharmacodynamic, Constituents of Traditional Chinese Medicine and New Drug Research, College of Pharmacy, Jinan University, Guangzhou, 510632, China.
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36
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Antón Z, Mullally G, Ford HC, van der Kamp MW, Szczelkun MD, Lane JD. Mitochondrial import, health and mtDNA copy number variability seen when using type II and type V CRISPR effectors. J Cell Sci 2020; 133:jcs.248468. [PMID: 32843580 DOI: 10.1242/jcs.248468] [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: 05/04/2020] [Accepted: 08/10/2020] [Indexed: 12/18/2022] Open
Abstract
Current methodologies for targeting the mitochondrial genome for research and/or therapy development in mitochondrial diseases are restricted by practical limitations and technical inflexibility. A molecular toolbox for CRISPR-mediated mitochondrial genome editing is desirable, as this could enable targeting of mtDNA haplotypes using the precision and tuneability of CRISPR enzymes. Such 'MitoCRISPR' systems described to date lack reproducibility and independent corroboration. We have explored the requirements for MitoCRISPR in human cells by CRISPR nuclease engineering, including the use of alternative mitochondrial protein targeting sequences and smaller paralogues, and the application of guide (g)RNA modifications for mitochondrial import. We demonstrate varied mitochondrial targeting efficiencies and effects on mitochondrial dynamics/function of different CRISPR nucleases, with Lachnospiraceae bacterium ND2006 (Lb) Cas12a being better targeted and tolerated than Cas9 variants. We also provide evidence of Cas9 gRNA association with mitochondria in HeLa cells and isolated yeast mitochondria, even in the absence of a targeting RNA aptamer. Our data link mitochondrial-targeted LbCas12a/crRNA with increased mtDNA copy number dependent upon DNA binding and cleavage activity. We discuss reproducibility issues and the future steps necessary for MitoCRISPR.
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Affiliation(s)
- Zuriñe Antón
- Cell Biology Laboratories, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Grace Mullally
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Holly C Ford
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Marc W van der Kamp
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK.,Centre for Computational Chemistry, School of Chemistry, Faculty of Science, University of Bristol, Bristol BS8 1TD, UK.,BrisSynBio, Life Sciences Building, Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, UK
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK .,BrisSynBio, Life Sciences Building, Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, UK
| | - Jon D Lane
- Cell Biology Laboratories, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK .,BrisSynBio, Life Sciences Building, Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, UK
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37
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Jackson CB, Turnbull DM, Minczuk M, Gammage PA. Therapeutic Manipulation of mtDNA Heteroplasmy: A Shifting Perspective. Trends Mol Med 2020; 26:698-709. [PMID: 32589937 DOI: 10.1016/j.molmed.2020.02.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 12/23/2022]
Abstract
Mutations of mitochondrial DNA (mtDNA) often underlie mitochondrial disease, one of the most common inherited metabolic disorders. Since the sequencing of the human mitochondrial genome and the discovery of pathogenic mutations in mtDNA more than 30 years ago, a movement towards generating methods for robust manipulation of mtDNA has ensued, although with relatively few advances and some controversy. While developments in the transformation of mammalian mtDNA have stood still for some time, recent demonstrations of programmable nuclease-based technology suggest that clinical manipulation of mtDNA heteroplasmy may be on the horizon for these largely untreatable disorders. Here we review historical and recent developments in mitochondrially targeted nuclease technology and the clinical outlook for treatment of hereditary mitochondrial disease.
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Affiliation(s)
- Christopher B Jackson
- Stem Cells and Metabolism, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Payam A Gammage
- CRUK Beatson Institute, Glasgow, UK; Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
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38
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Nissanka N, Moraes CT. Mitochondrial DNA heteroplasmy in disease and targeted nuclease-based therapeutic approaches. EMBO Rep 2020; 21:e49612. [PMID: 32073748 DOI: 10.15252/embr.201949612] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/11/2019] [Accepted: 01/29/2020] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial DNA (mtDNA) encodes a subset of the genes which are responsible for oxidative phosphorylation. Pathogenic mutations in the human mtDNA are often heteroplasmic, where wild-type mtDNA species co-exist with the pathogenic mtDNA and a bioenergetic defect is only seen when the pathogenic mtDNA percentage surpasses a threshold for biochemical manifestations. mtDNA segregation during germline development can explain some of the extreme variation in heteroplasmy from one generation to the next. Patients with high heteroplasmy for deleterious mtDNA species will likely suffer from bona-fide mitochondrial diseases, which currently have no cure. Shifting mtDNA heteroplasmy toward the wild-type mtDNA species could provide a therapeutic option to patients. Mitochondrially targeted engineered nucleases, such as mitoTALENs and mitoZFNs, have been used in vitro in human cells harboring pathogenic patient-derived mtDNA mutations and more recently in vivo in a mouse model of a pathogenic mtDNA point mutation. These gene therapy tools for shifting mtDNA heteroplasmy can also be used in conjunction with other therapies aimed at eliminating and/or preventing the transfer of pathogenic mtDNA from mother to child.
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Affiliation(s)
- Nadee Nissanka
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
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39
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Abstract
The mitochondrial genome encodes 13 proteins that are components of the oxidative phosphorylation system (OXPHOS), suggesting that precise regulation of these genes is crucial for maintaining OXPHOS functions, including ATP production, calcium buffering, cell signaling, ROS production, and apoptosis. Furthermore, heteroplasmy or mis-regulation of gene expression in mitochondria frequently is associated with human mitochondrial diseases. Thus, various approaches have been developed to investigate the roles of genes encoded by the mitochondrial genome. In this review, we will discuss a wide range of techniques available for investigating the mitochondrial genome, mitochondrial transcription, and mitochondrial translation, which provide a useful guide to understanding mitochondrial gene expression.
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Affiliation(s)
- Dongkeun Park
- Department of Biological Sciences, School of Life Sciences, Ulsan 44919, Korea
- National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Soyeon Lee
- Department of Biological Sciences, School of Life Sciences, Ulsan 44919, Korea
- National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Kyung-Tai Min
- Department of Biological Sciences, School of Life Sciences, Ulsan 44919, Korea
- National Creative Research Initiative Center for Proteostasis, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
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40
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Bacman SR, Gammage P, Minczuk M, Moraes CT. Manipulation of mitochondrial genes and mtDNA heteroplasmy. Methods Cell Biol 2020; 155:441-487. [DOI: 10.1016/bs.mcb.2019.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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41
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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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42
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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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43
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Hoitzing H, Gammage PA, Haute LV, Minczuk M, Johnston IG, Jones NS. Energetic costs of cellular and therapeutic control of stochastic mitochondrial DNA populations. PLoS Comput Biol 2019; 15:e1007023. [PMID: 31242175 PMCID: PMC6615642 DOI: 10.1371/journal.pcbi.1007023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 07/09/2019] [Accepted: 04/11/2019] [Indexed: 12/28/2022] Open
Abstract
The dynamics of the cellular proportion of mutant mtDNA molecules is crucial for mitochondrial diseases. Cellular populations of mitochondria are under homeostatic control, but the details of the control mechanisms involved remain elusive. Here, we use stochastic modelling to derive general results for the impact of cellular control on mtDNA populations, the cost to the cell of different mtDNA states, and the optimisation of therapeutic control of mtDNA populations. This formalism yields a wealth of biological results, including that an increasing mtDNA variance can increase the energetic cost of maintaining a tissue, that intermediate levels of heteroplasmy can be more detrimental than homoplasmy even for a dysfunctional mutant, that heteroplasmy distribution (not mean alone) is crucial for the success of gene therapies, and that long-term rather than short intense gene therapies are more likely to beneficially impact mtDNA populations.
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Affiliation(s)
- Hanne Hoitzing
- Department of Mathematics, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Payam A. Gammage
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, United Kingdom
- CRUK Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - Lindsey Van Haute
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, United Kingdom
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, United Kingdom
| | - Iain G. Johnston
- Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen, Norway
- Alan Turing Institute, London, United Kingdom
| | - Nick S. Jones
- Department of Mathematics, Imperial College London, London, SW7 2AZ, United Kingdom
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44
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Pereira CV, Bacman SR, Arguello T, Zekonyte U, Williams SL, Edgell DR, Moraes CT. mitoTev-TALE: a monomeric DNA editing enzyme to reduce mutant mitochondrial DNA levels. EMBO Mol Med 2019; 10:emmm.201708084. [PMID: 30012581 PMCID: PMC6127889 DOI: 10.15252/emmm.201708084] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Pathogenic mitochondrial DNA (mtDNA) mutations often co‐exist with wild‐type molecules (mtDNA heteroplasmy). Phenotypes manifest when the percentage of mutant mtDNA is high (70–90%). Previously, our laboratory showed that mitochondria‐targeted transcription activator‐like effector nucleases (mitoTALENs) can eliminate mutant mtDNA from heteroplasmic cells. However, mitoTALENs are dimeric and relatively large, making it difficult to package their coding genes into viral vectors, limiting their clinical application. The smaller monomeric GIY‐YIG homing nuclease from T4 phage (I‐TevI) provides a potential alternative. We tested whether molecular hybrids (mitoTev‐TALEs) could specifically bind and cleave mtDNA of patient‐derived cybrids harboring different levels of the m.8344A>G mtDNA point mutation, associated with myoclonic epilepsy with ragged‐red fibers (MERRF). We tested two mitoTev‐TALE designs, one of which robustly shifted the mtDNA ratio toward the wild type. When this mitoTev‐TALE was tested in a clone with high levels of the MERRF mutation (91% mutant), the shift in heteroplasmy resulted in an improvement of oxidative phosphorylation function. mitoTev‐TALE provides an effective architecture for mtDNA editing that could facilitate therapeutic delivery of mtDNA editing enzymes to affected tissues.
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Affiliation(s)
- Claudia V Pereira
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sandra R Bacman
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Tania Arguello
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Ugne Zekonyte
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sion L Williams
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - David R Edgell
- Department of Biochemistry, Schulich School of Medicine and Dentistry University of Western Ontario, London, ON, Canada
| | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
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45
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Bian WP, Chen YL, Luo JJ, Wang C, Xie SL, Pei DS. Knock-In Strategy for Editing Human and Zebrafish Mitochondrial DNA Using Mito-CRISPR/Cas9 System. ACS Synth Biol 2019; 8:621-632. [PMID: 30955321 DOI: 10.1021/acssynbio.8b00411] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mitochondria DNA (mtDNA) editing tool, zinc finger nucleases (ZFNs), transcription activator-like effector nuclease (TALENs), and clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (CRISPR/Cas9) system, is a promising approach for the treatment of mtDNA diseases by eliminating mutant mitochondrial genomes. However, there have been no reports of repairing the mutant mtDNA with homologous recombination strategy to date. Here, we show a mito-CRISPR/Cas9 system that mito-Cas9 protein can specifically target mtDNA and reduce mtDNA copy number in both human cells and zebrafish. An exogenous single-stranded DNA with short homologous arm was knocked into the targeting loci accurately, and this mutagenesis could be steadily transmitted to F1 generation of zebrafish. Moreover, we found some major factors involved in nuclear DNA repair were upregulated significantly by the mito-CRISPR/Cas9 system. Taken together, our data suggested that the mito-CRISPR/Cas9 system could be a useful method to edit mtDNA by knock-in strategy, providing a potential therapy for the treatment of inherited mitochondrial diseases.
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Affiliation(s)
- Wan-Ping Bian
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Yan-Ling Chen
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Juan-Juan Luo
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Chao Wang
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Shao-Lin Xie
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - De-Sheng Pei
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
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46
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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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47
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Murphy MP, Hartley RC. Mitochondria as a therapeutic target for common pathologies. Nat Rev Drug Discov 2018; 17:865-886. [PMID: 30393373 DOI: 10.1038/nrd.2018.174] [Citation(s) in RCA: 458] [Impact Index Per Article: 76.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Although the development of mitochondrial therapies has largely focused on diseases caused by mutations in mitochondrial DNA or in nuclear genes encoding mitochondrial proteins, it has been found that mitochondrial dysfunction also contributes to the pathology of many common disorders, including neurodegeneration, metabolic disease, heart failure, ischaemia-reperfusion injury and protozoal infections. Mitochondria therefore represent an important drug target for these highly prevalent diseases. Several strategies aimed at therapeutically restoring mitochondrial function are emerging, and a small number of agents have entered clinical trials. This Review discusses the opportunities and challenges faced for the further development of mitochondrial pharmacology for common pathologies.
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Affiliation(s)
- Michael P Murphy
- Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
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48
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Abstract
DNA methylation plays important roles in determining cellular identity, disease, and environmental responses, but little is known about the mechanisms that drive methylation changes during cellular differentiation and tumorigenesis. Meanwhile, the causal relationship between DNA methylation and transcription remains incompletely understood. Recently developed targeted DNA methylation manipulation tools can address these gaps in knowledge, leading to new insights into how methylation governs gene expression. Here, we summarize technological developments in the DNA methylation editing field and discuss the remaining challenges facing current tools, as well as potential future directions.
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Affiliation(s)
- Yong Lei
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, 77030, USA.,Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yung-Hsin Huang
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, 77030, USA.,Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, 77030, USA.,Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Margaret A Goodell
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, 77030, USA. .,Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, 77030, USA. .,Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
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49
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Genome editing in mitochondria corrects a pathogenic mtDNA mutation in vivo. Nat Med 2018; 24:1691-1695. [PMID: 30250142 PMCID: PMC6225988 DOI: 10.1038/s41591-018-0165-9] [Citation(s) in RCA: 185] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 07/26/2018] [Indexed: 02/06/2023]
Abstract
Mutations of the mitochondrial genome (mtDNA) underlie a substantial portion of mitochondrial disease burden. These disorders are currently incurable and effectively untreatable, with heterogeneous penetrance, presentation and prognosis. To address the lack of effective treatment for these disorders, we exploited a recently developed mouse model that recapitulates common molecular features of heteroplasmic mtDNA disease in cardiac tissue: the m.5024C>T tRNAAla mouse. Through application of a programmable nuclease therapy approach, using systemically administered, mitochondrially targeted zinc-finger nucleases (mtZFN) delivered by adeno-associated virus, we induced specific elimination of mutant mtDNA across the heart, coupled to a reversion of molecular and biochemical phenotypes. These findings constitute proof of principle that mtDNA heteroplasmy correction using programmable nucleases could provide a therapeutic route for heteroplasmic mitochondrial diseases of diverse genetic origin.
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50
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