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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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Peng SY, Chen CY, Chen H, Yang YP, Wang ML, Tsai FT, Chien CS, Weng PY, Tsai ET, Wang IC, Hsu CC, Lin TC, Hwang DK, Chen SJ, Chiou SH, Chiao CC, Chien Y. Inhibition of angiogenesis by the secretome from iPSC-derived retinal ganglion cells with Leber's hereditary optic neuropathy-like phenotypes. Biomed Pharmacother 2024; 178:117270. [PMID: 39126773 DOI: 10.1016/j.biopha.2024.117270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 08/01/2024] [Accepted: 08/05/2024] [Indexed: 08/12/2024] Open
Abstract
The blood supply in the retina ensures photoreceptor function and maintains regular vision. Leber's hereditary optic neuropathy (LHON), caused by the mitochondrial DNA mutations that deteriorate complex I activity, is characterized by progressive vision loss. Although some reports indicated retinal vasculature abnormalities as one of the comorbidities in LHON, the paracrine influence of LHON-affected retinal ganglion cells (RGCs) on vascular endothelial cell physiology remains unclear. To address this, we established an in vitro model of mitochondrial complex I deficiency using induced pluripotent stem cell-derived RGCs (iPSC-RGCs) treated with a mitochondrial complex I inhibitor rotenone (Rot) to recapitulate LHON pathologies. The secretomes from Rot-treated iPSC-RGCs (Rot-iPSC-RGCs) were collected, and their treatment effect on human umbilical vein endothelial cells (HUVECs) was studied. Rot induced LHON-like characteristics in iPSC-RGCs, including decreased mitochondrial complex I activity and membrane potential, and increased mitochondrial reactive oxygen species (ROS) and apoptosis, leading to mitochondrial dysfunction. When HUVECs were exposed to conditioned media (CM) from Rot-iPSC-RGCs, the angiogenesis of HUVECs was suppressed compared to those treated with CM from control iPSC-RGCs (Ctrl-iPSC-RGCs). Angiogenesis-related proteins were altered in the secretomes from Rot-iPSC-RGC-derived CM, particularly angiopoietin, MMP-9, uPA, collagen XVIII, and VEGF were reduced. Notably, GeneMANIA analysis indicated that VEGFA emerged as the pivotal angiogenesis-related protein among the identified proteins secreted by health iPSC-RGCs but reduced in the secretomes from Rot-iPSC-RGCs. Quantitative real-time PCR and western blots confirmed the reduction of VEGFA at both transcription and translation levels, respectively. Our study reveals that Rot-iPSC-RGCs establish a microenvironment to diminish the angiogenic potential of vascular cells nearby, shedding light on the paracrine regulation of LHON-affected RGCs on retinal vasculature.
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Affiliation(s)
- Shih-Yuan Peng
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC
| | - Chih-Ying Chen
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC
| | - Hsin Chen
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC; Institute of Molecular Medicine, National Tsing Hua University, Hsinchu 300044, Taiwan, ROC
| | - Yi-Ping Yang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC; Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang-Ming Chiao Tung University, Taipei 11221, Taiwan, ROC
| | - Mong-Lien Wang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC; Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang-Ming Chiao Tung University, Taipei 11221, Taiwan, ROC
| | - Fu-Ting Tsai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC
| | - Chian-Shiu Chien
- Institute of Physiology, National Yang Ming Chiao Tung University, Taiwan, ROC
| | - Pei-Yu Weng
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC
| | - En-Tung Tsai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC
| | - I-Chieh Wang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC
| | - Chih-Chien Hsu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan, ROC
| | - Tai-Chi Lin
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan, ROC
| | - De-Kuang Hwang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan, ROC
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan, ROC
| | - Shih-Hwa Chiou
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC; Institute of Pharmacology, School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan, ROC; Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan, ROC; Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan, ROC.
| | - Chuan-Chin Chiao
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu 300044, Taiwan, ROC.
| | - Yueh Chien
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan, ROC.
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Hawlina M, Kovač L, Breciková K, Žigmond J, Rogalewicz V, Tichopád A, Višňanský M, Šarkanová I. Leber hereditary optic neuropathy in Slovenia: quality of life and costs from patient perspective. Orphanet J Rare Dis 2024; 19:318. [PMID: 39215330 PMCID: PMC11365147 DOI: 10.1186/s13023-024-03329-0] [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: 05/30/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024] Open
Abstract
INTRODUCTION Leber hereditary optic neuropathy (LHON) is the most commonly diagnosed mitochondrial disorder, resulting in colour vision abnormalities and rapid but painless deterioration of central vision. While numerous studies have assessed the impact of LHON on the quality of life (QoL) of LHON patients, the financial impact of the disease remains unexplored. This study attempts to calculate both the direct non-medical costs and the indirect costs associated with productivity losses experienced by people with LHON and their unpaid caregivers in Slovenia, in addition to assessing their QoL. Due to the rarity of the disease, the study involved a small sample size, which is important to note for interpreting the results. METHODS The analysis was conducted on nine adult participants diagnosed with LHON, representing one-third of the total number of known Slovenian patients with this condition. To thoroughly assess the economic and social impact of LHON, tailored questionnaires were designed to collect information on demographics, socioeconomic status, LHON severity, and associated non-medical and indirect costs. RESULTS The mean age of the study participants was 48.8 years (SD 13.3; n = 9). The annual productivity loss attributable to LHON, taking both absenteeism and relative presenteeism into account, was calculated to be EUR 11,608 per person affected. The mean VFQ-25 score, a measure of vision-related quality of life, for adult LHON patients was 30.4 (SD 12.9). CONCLUSION The findings highlight the significant economic and social burden of LHON on patients and their families. Ensuring prompt, accurate diagnosis, access to treatment, financial support, and psychological counselling and services are critical to helping individuals cope with and mitigate the profound challenges of vision loss and living with LHON.
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Affiliation(s)
- Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Lea Kovač
- Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | | | - Jan Žigmond
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University Prague, Kladno, Czechia
| | - Vladimír Rogalewicz
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University Prague, Kladno, Czechia
| | - Aleš Tichopád
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University Prague, Kladno, Czechia
| | - Martin Višňanský
- Department of Pharmacy and Social Pharmacy, University of Veterinary Medicine and Pharmacy Košice, Košice, Slovakia
- Department of Public Economics, Faculty of Economics and Administration, Masaryk University Brno, Brno, Czechia
| | - Ivana Šarkanová
- CEEOR s.r.o., Prague, Czechia
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University Prague, Kladno, Czechia
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Yang TH, Kang EYC, Lin PH, Yu BBC, Wang JHH, Chen V, Wang NK. Mitochondria in Retinal Ganglion Cells: Unraveling the Metabolic Nexus and Oxidative Stress. Int J Mol Sci 2024; 25:8626. [PMID: 39201313 PMCID: PMC11354650 DOI: 10.3390/ijms25168626] [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: 05/31/2024] [Revised: 07/29/2024] [Accepted: 07/29/2024] [Indexed: 09/02/2024] Open
Abstract
This review explored the role of mitochondria in retinal ganglion cells (RGCs), which are essential for visual processing. Mitochondrial dysfunction is a key factor in the pathogenesis of various vision-related disorders, including glaucoma, hereditary optic neuropathy, and age-related macular degeneration. This review highlighted the critical role of mitochondria in RGCs, which provide metabolic support, regulate cellular health, and respond to cellular stress while also producing reactive oxygen species (ROS) that can damage cellular components. Maintaining mitochondrial function is essential for meeting RGCs' high metabolic demands and ensuring redox homeostasis, which is crucial for their proper function and visual health. Oxidative stress, exacerbated by factors like elevated intraocular pressure and environmental factors, contributes to diseases such as glaucoma and age-related vision loss by triggering cellular damage pathways. Strategies targeting mitochondrial function or bolstering antioxidant defenses include mitochondrial-based therapies, gene therapies, and mitochondrial transplantation. These advances can offer potential strategies for addressing mitochondrial dysfunction in the retina, with implications that extend beyond ocular diseases.
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Affiliation(s)
- Tsai-Hsuan Yang
- Department of Education, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 33305, Taiwan;
- College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Eugene Yu-Chuan Kang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 33305, Taiwan;
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-H.L.); (J.H.-H.W.); (V.C.)
| | - Pei-Hsuan Lin
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-H.L.); (J.H.-H.W.); (V.C.)
- National Taiwan University Hospital, Yunlin 640203, Taiwan
| | - Benjamin Ben-Chi Yu
- Fu Foundation School of Engineering & Applied Science, Columbia University, New York, NY 10027, USA;
| | - Jason Hung-Hsuan Wang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-H.L.); (J.H.-H.W.); (V.C.)
- Columbian College of Arts and Sciences, George Washington University, Washington, DC 20052, USA
| | - Vincent Chen
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-H.L.); (J.H.-H.W.); (V.C.)
- Faculty of Health Sciences, Queen’s University, Kingston, ON K7L 3N9, Canada
| | - Nan-Kai Wang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 33305, Taiwan;
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA
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Chapelle AC, Rakic JM, Plant GT. Utility of ganglion cells for the evaluation of anterior visual pathway pathology: a review. Acta Neurol Belg 2024; 124:1113-1123. [PMID: 38538906 DOI: 10.1007/s13760-024-02522-z] [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: 11/29/2023] [Accepted: 03/01/2024] [Indexed: 07/25/2024]
Abstract
The management of optic neuropathy is fundamental to neuro-ophthalmic practice. Following the invention of the ophthalmoscope, clinicians, for a century or more, relied upon fundus examination in the evaluation of optic neuropathy. However, the advent of optical coherence tomography, based on the principle of backscattering of light and interferometry, has revolutionized the analysis of optic nerve and retinal disorders. Optical coherence tomography has proven of particular value in the measurement, at the micron level, of the peripapillary retinal nerve fibre layer and the ganglion cell layer. These measurements have proven critical in the differential diagnosis and monitoring of optic neuropathy. Specifically, thinning of the peripapillary nerve fibre layer provides evidence of axonal loss affecting any sector of the optic nerve. Thinning of the macular ganglion cell layer, on the other hand, shows a more precise correlation with visual deficits due to retrograde degeneration following optic nerve damage, although limited to central retina. In daily practise, optical coherence tomography is of great value in assessing the diagnosis, prognosis and response to treatment in optic neuropathy. Particular advances have been made, for example, in the assessment of optic neuritis, papilloedema and chiasmal compression which have translated to everyday practice. As with any other imaging technology the clinician must have a clear understanding of acquisition artefacts. A further issue is the relatively limited normative database in sub-populations such as the young and individuals with a refractive error > + 5 or < -5 dioptres.
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Affiliation(s)
- Anne-Catherine Chapelle
- Department of Ophthalmology, Central University Hospital of Liège, University of Liège, Avenue de L'hôpital, 4000, Liège, Belgium.
| | - Jean-Marie Rakic
- Department of Ophthalmology, Central University Hospital of Liège, University of Liège, Avenue de L'hôpital, 4000, Liège, Belgium
| | - Gordon Terence Plant
- Department of Neurodegeneration and Rehabilitation, Faculty of Brain Sciences, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK
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Alorainy J, Alorfi Y, Karanjia R, Badeeb N. A Comprehensive Review of Leber Hereditary Optic Neuropathy and Its Association with Multiple Sclerosis-Like Phenotypes Known as Harding's Disease. Eye Brain 2024; 16:17-24. [PMID: 39100385 PMCID: PMC11296356 DOI: 10.2147/eb.s470184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Accepted: 07/23/2024] [Indexed: 08/06/2024] Open
Abstract
Leber Hereditary Optic Neuropathy (LHON) stands as a distinctive maternally inherited mitochondrial disorder marked by painless, subacute central vision loss, primarily affecting young males. This review covers the possible relationship between LHON and multiple sclerosis (MS), covering genetic mutations, clinical presentations, imaging findings, and treatment options. LHON is associated with mutations in mitochondrial DNA (mtDNA), notably m.11778G>A, m.3460G>A, and m.14484T>C, affecting complex I subunits. Beyond ocular manifestations, LHON can go beyond the eye into a multi-systemic disorder, showcasing extraocular abnormalities. Clinical presentations, varying in gender prevalence and outcomes, underscore the nature of mitochondrial optic neuropathies. Hypotheses exploring the connection between LHON and MS encompass mitochondrial DNA mutations triggering neurological diseases, immunologically mediated responses inducing demyelination, and the possibility of coincidental diseases. The research on mtDNA mutations among MS patients sheds light on potential associations with specific clinical subgroups, offering a unique perspective into the broader landscape of MS. Imaging findings, ranging from white matter alterations to cerebrospinal fluid biomarkers, further emphasize shared pathological processes between LHON-MS and classical MS. This comprehensive review contributes to the understanding of the complex relationship between LHON and MS.
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Affiliation(s)
- Jehad Alorainy
- College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Yara Alorfi
- Faculty of Medicine, University of Jeddah, Jeddah, Saudi Arabia
| | - Rustum Karanjia
- Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at UCLA, UCLA Stein Eye Institute, Los Angeles, CA, 90095-7000, USA
- Ottawa Hospital Research Institute, the Ottawa Hospital, Ottawa, Canada
- Doheny Eye Institute, Los Angeles, CA, USA
| | - Nooran Badeeb
- Department of Ophthalmology, University of Jeddah, Jeddah, Saudi Arabia
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Hao Z, Zhang Z, Jiang J, Pan L, Zhang J, Cui X, Li Y, Li J, Luo L. Complete mitochondrial genome of Melia azedarach L., reveals two conformations generated by the repeat sequence mediated recombination. BMC PLANT BIOLOGY 2024; 24:645. [PMID: 38972991 PMCID: PMC11229266 DOI: 10.1186/s12870-024-05319-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 06/21/2024] [Indexed: 07/09/2024]
Abstract
Melia azedarach is a species of enormous value of pharmaceutical industries. Although the chloroplast genome of M. azedarach has been explored, the information of mitochondrial genome (Mt genome) remains surprisingly limited. In this study, we used a hybrid assembly strategy of BGI short-reads and Nanopore long-reads to assemble the Mt genome of M. azedarach. The Mt genome of M. azedarach is characterized by two circular chromosomes with 350,142 bp and 290,387 bp in length, respectively, which encodes 35 protein-coding genes (PCGs), 23 tRNA genes, and 3 rRNA genes. A pair of direct repeats (R1 and R2) were associated with genome recombination, resulting in two conformations based on the Sanger sequencing and Oxford Nanopore sequencing. Comparative analysis identified 19 homologous fragments between Mt and chloroplast genome, with the longest fragment of 12,142 bp. The phylogenetic analysis based on PCGs were consist with the latest classification of the Angiosperm Phylogeny Group. Notably, a total of 356 potential RNA editing sites were predicted based on 35 PCGs, and the editing events lead to the formation of the stop codon in the rps10 gene and the start codons in the nad4L and atp9 genes, which were verified by PCR amplification and Sanger sequencing. Taken together, the exploration of M. azedarach gap-free Mt genome provides a new insight into the evolution research and complex mitogenome architecture.
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Affiliation(s)
- Zhigang Hao
- Sanya Institute of China Agricultural University, Sanya, Hainan, 572025, China
- Department of Plant Pathology, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
- Hainan Seed Industry Laboratory, Sanya, Hainan, 572025, China
| | - Zhiping Zhang
- Department of Pesticide Science, College of Plant Protection, State Key Laboratory for Conservation and Utilization of Bio-Resource in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
- Key Laboratory of Vegetable Biology of Yunnan Province, College of Landscape and Horticulture, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Juan Jiang
- Sanya Institute of China Agricultural University, Sanya, Hainan, 572025, China
| | - Lei Pan
- CAIQ Center for Biosafety in Sanya, Sanya, Hainan, 572000, China
| | - Jinan Zhang
- Sanya Institute of China Agricultural University, Sanya, Hainan, 572025, China
- Department of Plant Pathology, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Xiufen Cui
- Sanya Institute of China Agricultural University, Sanya, Hainan, 572025, China
- Department of Plant Pathology, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Yingbin Li
- Department of Pesticide Science, College of Plant Protection, State Key Laboratory for Conservation and Utilization of Bio-Resource in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Jianqiang Li
- Sanya Institute of China Agricultural University, Sanya, Hainan, 572025, China.
- Department of Plant Pathology, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China.
| | - Laixin Luo
- Sanya Institute of China Agricultural University, Sanya, Hainan, 572025, China.
- Department of Plant Pathology, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China.
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Piergentili R, Sechi S. Non-Coding RNAs of Mitochondrial Origin: Roles in Cell Division and Implications in Cancer. Int J Mol Sci 2024; 25:7498. [PMID: 39000605 PMCID: PMC11242419 DOI: 10.3390/ijms25137498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/01/2024] [Accepted: 07/05/2024] [Indexed: 07/16/2024] Open
Abstract
Non-coding RNAs (ncRNAs) are a heterogeneous group, in terms of structure and sequence length, consisting of RNA molecules that do not code for proteins. These ncRNAs have a central role in the regulation of gene expression and are virtually involved in every process analyzed, ensuring cellular homeostasis. Although, over the years, much research has focused on the characterization of non-coding transcripts of nuclear origin, improved bioinformatic tools and next-generation sequencing (NGS) platforms have allowed the identification of hundreds of ncRNAs transcribed from the mitochondrial genome (mt-ncRNA), including long non-coding RNA (lncRNA), circular RNA (circRNA), and microRNA (miR). Mt-ncRNAs have been described in diverse cellular processes such as mitochondrial proteome homeostasis and retrograde signaling; however, the function of the majority of mt-ncRNAs remains unknown. This review focuses on a subgroup of human mt-ncRNAs whose dysfunction is associated with both failures in cell cycle regulation, leading to defects in cell growth, cell proliferation, and apoptosis, and the development of tumor hallmarks, such as cell migration and metastasis formation, thus contributing to carcinogenesis and tumor development. Here we provide an overview of the mt-ncRNAs/cancer relationship that could help the future development of new biomedical applications in the field of oncology.
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Affiliation(s)
| | - Stefano Sechi
- Istituto di Biologia e Patologia Molecolari del Consiglio Nazionale delle Ricerche, Dipartimento di Biologia e Biotecnologie, Università Sapienza di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy;
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9
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Toshima T, Yagi M, Do Y, Hirai H, Kunisaki Y, Kang D, Uchiumi T. Mitochondrial translation failure represses cholesterol gene expression via Pyk2-Gsk3β-Srebp2 axis. Life Sci Alliance 2024; 7:e202302423. [PMID: 38719751 PMCID: PMC11079605 DOI: 10.26508/lsa.202302423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 04/27/2024] [Accepted: 04/29/2024] [Indexed: 05/12/2024] Open
Abstract
Neurodegenerative diseases and other age-related disorders are closely associated with mitochondrial dysfunction. We previously showed that mice with neuron-specific deficiency of mitochondrial translation exhibit leukoencephalopathy because of demyelination. Reduced cholesterol metabolism has been associated with demyelinating diseases of the brain such as Alzheimer's disease. However, the molecular mechanisms involved and relevance to the pathogenesis remained unknown. In this study, we show that inhibition of mitochondrial translation significantly reduced expression of the cholesterol synthase genes and degraded their sterol-regulated transcription factor, sterol regulatory element-binding protein 2 (Srebp2). Furthermore, the phosphorylation of Pyk2 and Gsk3β was increased in the white matter of p32cKO mice. We observed that Pyk2 inhibitors reduced the phosphorylation of Gsk3β and that GSK3β inhibitors suppressed degradation of the transcription factor Srebp2. The Pyk2-Gsk3β axis is involved in the ubiquitination of Srebp2 and reduced expression of cholesterol gene. These results suggest that inhibition of mitochondrial translation may be a causative mechanism of neurodegenerative diseases of aging. Improving the mitochondrial translation or effectiveness of Gsk3β inhibitors is a potential therapeutic strategy for leukoencephalopathy.
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Affiliation(s)
- Takahiro Toshima
- https://ror.org/00p4k0j84 Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan
- https://ror.org/00p4k0j84 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Mikako Yagi
- https://ror.org/00p4k0j84 Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan
- https://ror.org/00p4k0j84 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yura Do
- https://ror.org/00p4k0j84 Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan
| | - Haruka Hirai
- https://ror.org/00p4k0j84 Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan
- https://ror.org/00p4k0j84 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yuya Kunisaki
- https://ror.org/00p4k0j84 Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan
| | - Dongchon Kang
- https://ror.org/00p4k0j84 Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan
- Kashiigaoka Rehabilitation Hospital, Fukuoka, Japan
- Department of Medical Laboratory Science, Faculty of Health Sciences, Junshin Gakuen University, Fukuoka, Japan
| | - Takeshi Uchiumi
- https://ror.org/00p4k0j84 Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan
- https://ror.org/00p4k0j84 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Borrelli E, Bandello F, Boon CJF, Carelli V, Lenaers G, Reibaldi M, Sadda SR, Sadun AA, Sarraf D, Yu-Wai-Man P, Barboni P. Mitochondrial retinopathies and optic neuropathies: The impact of retinal imaging on modern understanding of pathogenesis, diagnosis, and management. Prog Retin Eye Res 2024; 101:101264. [PMID: 38703886 DOI: 10.1016/j.preteyeres.2024.101264] [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: 01/11/2024] [Revised: 03/18/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
Advancements in ocular imaging have significantly broadened our comprehension of mitochondrial retinopathies and optic neuropathies by examining the structural and pathological aspects of the retina and optic nerve in these conditions. This article aims to review the prominent imaging characteristics associated with mitochondrial retinopathies and optic neuropathies, aiming to deepen our insight into their pathogenesis and clinical features. Preceding this exploration, the article provides a detailed overview of the crucial genetic and clinical features, which is essential for the proper interpretation of in vivo imaging. More importantly, we will provide a critical analysis on how these imaging modalities could serve as biomarkers for characterization and monitoring, as well as in guiding treatment decisions. However, these imaging methods have limitations, which will be discussed along with potential strategies to mitigate them. Lastly, the article will emphasize the potential advantages and future integration of imaging techniques in evaluating patients with mitochondrial eye disorders, considering the prospects of emerging gene therapies.
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Affiliation(s)
- Enrico Borrelli
- Department of Surgical Sciences, University of Turin, Turin, Italy; Department of Ophthalmology, "City of Health and Science" Hospital, Turin, Italy.
| | - Francesco Bandello
- Vita-Salute San Raffaele University, Milan, Italy; IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Camiel J F Boon
- Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, the Netherlands; Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Valerio Carelli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Guy Lenaers
- Equipe MitoLab, Unité MitoVasc, INSERM U1083, Université d'Angers, 49933, Angers, France; Service de Neurologie, CHU d'Angers, 49100, Angers, France
| | - Michele Reibaldi
- Department of Surgical Sciences, University of Turin, Turin, Italy; Department of Ophthalmology, "City of Health and Science" Hospital, Turin, Italy
| | - Srinivas R Sadda
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - Alfredo A Sadun
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - David Sarraf
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Patrick Yu-Wai-Man
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Institute of Ophthalmology, University College London, London, UK
| | - Piero Barboni
- IRCCS San Raffaele Scientific Institute, Milan, Italy; Studio Oculistico d'Azeglio, Bologna, Italy.
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11
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Rigobello L, Lugli F, Caporali L, Bartocci A, Fadanni J, Zerbetto F, Iommarini L, Carelli V, Ghelli AM, Musiani F. A computational study to assess the pathogenicity of single or combinations of missense variants on respiratory complex I. Int J Biol Macromol 2024; 273:133086. [PMID: 38871105 DOI: 10.1016/j.ijbiomac.2024.133086] [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: 03/21/2024] [Revised: 06/07/2024] [Accepted: 06/09/2024] [Indexed: 06/15/2024]
Abstract
Variants found in the respiratory complex I (CI) subunit genes encoded by mitochondrial DNA can cause severe genetic diseases. However, it is difficult to establish a priori whether a single or a combination of CI variants may impact oxidative phosphorylation. Here we propose a computational approach based on coarse-grained molecular dynamics simulations aimed at investigating new CI variants. One of the primary CI variants associated with the Leber hereditary optic neuropathy (m.14484T>C/MT-ND6) was used as a test case and was investigated alone or in combination with two additional rare CI variants whose role remains uncertain. We found that the primary variant positioned in the E-channel region, which is fundamental for CI function, stiffens the enzyme dynamics. Moreover, a new mechanism for the transition between π- and α-conformation in the helix carrying the primary variant is proposed. This may have implications for the E-channel opening/closing mechanism. Finally, our findings show that one of the rare variants, located next to the primary one, further worsens the stiffening, while the other rare variant does not affect CI function. This approach may be extended to other variants candidate to exert a pathogenic impact on CI dynamics, or to investigate the interaction of multiple variants.
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Affiliation(s)
- Laura Rigobello
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna I-40127, Italy
| | - Francesca Lugli
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna I-40126, Italy.
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna I-40124, Italy
| | - Alessio Bartocci
- Department of Physics, University of Trento, Trento I-38123, Italy; INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, Trento I-38123, Italy
| | - Jacopo Fadanni
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna I-40126, Italy
| | - Francesco Zerbetto
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna I-40126, Italy
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna I-40127, Italy
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna I-40124, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna I-40123, Italy
| | - Anna Maria Ghelli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna I-40127, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna I-40124, Italy
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna I-40127, Italy.
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Nagy MA, Cunnane ME, Juliano AF, Wiggs JL, Caruso PA, Gaier ED. Optic Nerve T2 Signal Intensity and Caliber Reflect Clinical Severity in Genetic Optic Atrophy. J Neuroophthalmol 2024:00041327-990000000-00661. [PMID: 38880955 DOI: 10.1097/wno.0000000000002191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
BACKGROUND Genetic optic atrophies comprise phenotypically heterogenous disorders of mitochondrial function. We aimed to correlate quantitative neuroimaging findings of the optic nerves in these disorders with clinical measures. METHODS From a retrospective database of 111 patients with bilateral optic atrophy referred for genetic testing, 15 patients diagnosed with nonglaucomatous optic atrophy of genetic origin (7 patients with pathogenic variants in OPA1, 3 patients with Wolfram syndrome, and 5 patients with Leber hereditary optic neuropathy) who had accessible magnetic resonance (MR) images of the orbits and/or brain were analyzed. The primary outcome measures of T2 short Tau inversion recovery (STIR) signal and optic nerve caliber were quantified according to a standardized protocol, normalized to internal standards, and compared between cases and controls. Inter-rater reliability was assessed and clinical features were analyzed according to MRI features. RESULTS Compared with control patients, the 15 genetic optic atrophy patients demonstrated significantly increased T2 STIR signal (fold-change 1.6, P = 0.0016) and decreased optic nerve caliber (fold-change 0.72, P = 0.00012) after internal normalization. These metrics were reliable (inter-reader reliability correlation coefficients of 0.98 [P = 0.00036] and 0.74 [P = 0.0025] for normalized STIR and nerve caliber, respectively) and significantly correlated with visual acuity, cup-to-disc ratio, and visual field testing. CONCLUSION Normalized optic nerve STIR signal and optic nerve caliber significantly correlate with visual acuity, cup-to-disc ratio, and perimetric performance in patients with genetic optic atrophy. A formalized protocol to characterize these differences on MRI may help to guide accurate and expedient diagnostic evaluation.
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Affiliation(s)
- M Aurel Nagy
- Harvard Medical School (MAN, MEC, AFJ, JLW, EDG), Boston, Massachusetts; Department of Ophthalmology (MAN), University of California San Francisco, California; Departments of Radiology (MEC, AFJ) and Ophthalmology (JLW, EDG), Massachusetts Eye and Ear, Boston, Massachusetts; Neuroradiology Division (PAC), Lenox Hill Radiology and Medical Imaging Associates, RadNet, New York, New York; Department of Ophthalmology (EDG), Boston Children's Hospital, Boston, Massachusetts; and Picower Institute for Learning and Memory (EDG), Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
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13
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Bušányová B, Vajter M, Kelifová S, Lišková P, Miková H, Breciková K, Žigmond J, Rogalewicz V, Tichopád A, Višňanský M, Šarkanová I. Leber hereditary optic neuropathy in Czechia and Slovakia: Quality of life and costs from patient perspective. Heliyon 2024; 10:e32296. [PMID: 38961918 PMCID: PMC11219317 DOI: 10.1016/j.heliyon.2024.e32296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 07/05/2024] Open
Abstract
Introduction Leber hereditary optic neuropathy (LHON) is the most frequent mitochondrial disease causing dyschromatopsia and progressive central visual loss that is subacute in progression and painless. Several studies have been published assessing QoL in patients with LHON, but no estimate of the economic burden has been reported to date. This study aims to quantify direct non-medical and indirect costs (productivity loss) incurred by LHON patients and their informal caregivers in Czechia and Slovakia, as well as to assess their quality of life. Methods The study was performed in 27 adults and children with LHON. To determine the socioeconomic burden of LHON, separate questionnaires for adults, children, and their parents were developed, including demographic and socioeconomic data. The following data were collected: age, education, family size, severity of LHON, non-medical direct and indirect costs of LHON. Results The mean age of adult respondents was 36.1 years (SD 13.1; n = 21). The total cost of absenteeism was EUR 1003 per person/year in adult employees, and EUR 2711 per person/year in children's parents. The productivity loss as a consequence of LHON due to combined relative absenteeism and relative presenteeism was estimated at EUR 9840 per an adult patient/year, and EUR 6298 per a parent/year, respectively. The mean cost of informal care was estimated at EUR 4502 (SD 4772; n = 6) per person/year. The mean VFQ-25 score for adult patients with LHON was 43.47 (SD 15.86). Conclusion The results of this study clearly show that patients with LHON and their families face an extensive socioeconomic burden related to this rare disease. Early, timely and appropriate access to diagnosis, treatment, and reimbursement decisions, but also to psychological counselling and services may help the patients and their relatives adapt and cope with the challenging aspects of vision loss and life with the disease.
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Affiliation(s)
- Beáta Bušányová
- Department of Paediatric Ophthalmology of the Faculty of Medicine, Comenius University Bratislava, And the National Institute of Children's Diseases in Bratislava, Slovakia
| | - Marie Vajter
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic
| | - Silvie Kelifová
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic
| | - Petra Lišková
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic
| | - Hedviga Miková
- Ophthalmological Outpatient Clinic, University Hospital - St. Michael's Hospital, Bratislava, Slovakia
| | | | - Ján Žigmond
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Vladimír Rogalewicz
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Aleš Tichopád
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Martin Višňanský
- Department of Pharmacy and Social Pharmacy, University of Veterinary Medicine and Pharmacy in Košice, Slovakia
- Department of Public Economics, Faculty of Economics and Administration, Masaryk University in Brno, Czech Republic
| | - Ivana Šarkanová
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
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Zhang D, Deng W, Jiang T, Zhao Y, Bai D, Tian Y, Kong S, Zhang L, Wang H, Gao S, Lu Z. Maternal Ezh1/2 deficiency impairs the function of mitochondria in mouse oocytes and early embryos. J Cell Physiol 2024; 239:e31244. [PMID: 38529784 DOI: 10.1002/jcp.31244] [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: 09/06/2023] [Revised: 02/23/2024] [Accepted: 02/27/2024] [Indexed: 03/27/2024]
Abstract
Maternal histone methyltransferase is critical for epigenetic regulation and development of mammalian embryos by regulating histone and DNA modifications. Here, we reported a novel mechanism by revealing the critical effects of maternal Ezh1/2 deletion on mitochondria in MII oocytes and early embryos in mice. We found that Ezh1/2 knockout in mouse MII oocytes impaired the structure of mitochondria and decreased its number, but membrane potential and respiratory function of mitochondrion were increased. The similar effects of Ezh1/2 deletion have been observed in 2-cell and morula embryos, indicating that the effects of maternal Ezh1/2 deficiency on mitochondrion extend to early embryos. However, the loss of maternal Ezh1/2 resulted in a severe defect of morula: the number, membrane potential, respiratory function, and ATP production of mitochondrion dropped significantly. Content of reactive oxygen species was raised in both MII oocytes and early embryos, suggesting maternal Ezh1/2 knockout induced oxidative stress. In addition, maternal Ezh1/2 ablation interfered the autophagy in morula and blastocyst embryos. Finally, maternal Ezh1/2 deletion led to cell apoptosis in blastocyst embryos in mice. By analyzing the gene expression profile, we revealed that maternal Ezh1/2 knockout affected the expression of mitochondrial related genes in MII oocytes and early embryos. The chromatin immunoprecipitation-polymerase chain reaction assay demonstrated that Ezh1/2 directly regulated the expression of genes Fxyd6, Adpgk, Aurkb, Zfp521, Ehd3, Sgms2, Pygl, Slc1a1, and Chst12 by H3K27me3 modification. In conclusion, our study revealed the critical effect of maternal Ezh1/2 on the structure and function of mitochondria in oocytes and early embryos, and suggested a novel mechanism underlying maternal epigenetic regulation on early embryonic development through the modulation of mitochondrial status.
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Affiliation(s)
- Dan Zhang
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen, Fujian, China
| | - Wenbo Deng
- Fujian Provincial Key Laboratory of Reproductive Health Research, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Ting Jiang
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen, Fujian, China
| | - Yinan Zhao
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen, Fujian, China
| | - Dandan Bai
- Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yingpu Tian
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen, Fujian, China
| | - Shuangbo Kong
- Fujian Provincial Key Laboratory of Reproductive Health Research, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Leilei Zhang
- Fujian Provincial Key Laboratory of Reproductive Health Research, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Haibin Wang
- Fujian Provincial Key Laboratory of Reproductive Health Research, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Shaorong Gao
- Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhongxian Lu
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen, Fujian, China
- Fujian Provincial Key Laboratory of Reproductive Health Research, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
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15
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Zhang CJ, Mou H, Yuan J, Wang YH, Sun SN, Wang W, Xu ZH, Yu SJ, Jin K, Jin ZB. Effects of fluorescent protein tdTomato on mouse retina. Exp Eye Res 2024; 243:109910. [PMID: 38663720 DOI: 10.1016/j.exer.2024.109910] [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: 06/14/2023] [Revised: 02/26/2024] [Accepted: 04/22/2024] [Indexed: 04/30/2024]
Abstract
Fluorescent proteins (FPs) have been widely used to investigate cellular and molecular interactions and trace biological events in many applications. Some of the FPs have been demonstrated to cause undesirable cellular damage by light-induced ROS production in vivo or in vitro. However, it remains unknown if one of the most popular FPs, tdTomato, has similar effects in neuronal cells. In this study, we discovered that tdTomato expression led to unexpected retinal dysfunction and ultrastructural defects in the transgenic mouse retina. The retinal dysfunction mainly manifested in the reduced photopic electroretinogram (ERG) responses and decreased contrast sensitivity in visual acuity, caused by mitochondrial damages characterized with cellular redistribution, morphological modifications and molecular profiling alterations. Taken together, our findings for the first time demonstrated the retinal dysfunction and ultrastructural defects in the retinas of tdTomato-transgenic mice, calling for a more careful design and interpretation of experiments involved in FPs.
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Affiliation(s)
- Chang-Jun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Hao Mou
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Jing Yuan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Ya-Han Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Shu-Ning Sun
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Wen Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Ze-Hua Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Si-Jian Yu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Kangxin Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China.
| | - Zi-Bing Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China.
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Pasqualotto BA, Tegeman C, Frame AK, McPhedrain R, Halangoda K, Sheldon CA, Rintoul GL. Galactose-replacement unmasks the biochemical consequences of the G11778A mitochondrial DNA mutation of LHON in patient-derived fibroblasts. Exp Cell Res 2024; 439:114075. [PMID: 38710404 DOI: 10.1016/j.yexcr.2024.114075] [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: 11/16/2023] [Revised: 04/30/2024] [Accepted: 05/03/2024] [Indexed: 05/08/2024]
Abstract
Leber's hereditary optic neuropathy (LHON) is a visual impairment associated with mutations of mitochondrial genes encoding elements of the electron transport chain. While much is known about the genetics of LHON, the cellular pathophysiology leading to retinal ganglion cell degeneration and subsequent vision loss is poorly understood. The impacts of the G11778A mutation of LHON on bioenergetics, redox balance and cell proliferation were examined in patient-derived fibroblasts. Replacement of glucose with galactose in the culture media reveals a deficit in the proliferation of G11778A fibroblasts, imparts a reduction in ATP biosynthesis, and a reduction in capacity to accommodate exogenous oxidative stress. While steady-state ROS levels were unaffected by the LHON mutation, cell survival was diminished in response to exogenous H2O2.
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Affiliation(s)
- Bryce A Pasqualotto
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Carina Tegeman
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Ariel K Frame
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Ryan McPhedrain
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Kolitha Halangoda
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Claire A Sheldon
- Dept. of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Gordon L Rintoul
- Department of Biological Sciences and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada.
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17
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Esteban-Vasallo MD, Domínguez-Berjón MF, Chalco-Orrego JP, González Martín-Moro J. Prevalence of Leber hereditary optic neuropathy in the Community of Madrid (Spain), estimation with a capture-recapture method. Orphanet J Rare Dis 2024; 19:220. [PMID: 38811977 PMCID: PMC11137926 DOI: 10.1186/s13023-024-03225-7] [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: 12/20/2023] [Accepted: 05/19/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND Leber hereditary optic neuropathy (LHON) typically presents in young adults as bilateral painless subacute visual loss. Prevalence data are scarce. The aim of this study was to examine the validity of different ascertainment sources used in population-based rare diseases registries to detect cases, and to explore the impact of a capture-recapture method in the estimation of the prevalence of LHON in the Autonomous Community of Madrid (ACM) in 2022. METHODS Descriptive cross-sectional population-based study. Potential LHON cases were detected by automatic capture from the healthcare information sources usually explored for the Regional Registry for Rare Diseases (SIERMA). Ophthalmologists provided data from their clinical registry. Positive predictive values (PPV) and sensitivity with 95% confidence intervals (CI) were estimated. Global and by sex prevalences were calculated with confimed cases and with those estimated by the capture-recapture method. RESULTS A total of 102 potential LHON cases were captured from healthcare information sources, 25 of them (24.5%) finally were confirmed after revision, with an overall PPV of 24.5% (95%CI 17.2-33.7). By source, the electronic clinical records of primary care had the highest PPV (51.2, 95%CI 36.7-65.4). The ophthalmologists clinical registry provided 22 cases, 12 of them not detected in the automatic capture sources. The clinical registry reached a sensitivity of 59.5% (95%CI 43.5-73.6) and the combination of automatic capture sources reached a 67.6% (95%CI: 51.5-80.4). The total confirmed cases were 37, with a mean age of 48.9 years, and a men: women ratio of 2.4:1. Genetic information was recovered in 27 cases, with the m.3460 mutation being the most frequent (12 cases). The global prevalence was 0.55 cases/100,000 inhabitants (95%CI 0.40-0.75), and with the capture-recapture method reached 0.79 cases/100,000 (95%CI 0.60-1.03), a 43.6% higher, 1.15 cases/100,000 (95%CI 0.83-1.58) in men and 0.43 cases/100,000 (95%CI 0.26-0.70) in women. CONCLUSIONS The prevalence of LHON estimated in the ACM was lower than in other European countries. Population-based registries of rare diseases require the incorporation of confirmed cases provided by clinicians to asure the best completeness of data. The use of more specific coding for rare diseases in healthcare information systems would facilitate the detection of cases. Further epidemiologic studies are needed to assess potential factors that may influence the penetrance of LHON.
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Affiliation(s)
| | | | | | - Julio González Martín-Moro
- Department of Ophthalmology, University Hospital of Henares. Coslada, Madrid, Spain
- Faculty of Medicine, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
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18
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Guo L, Lao G, He L, Xiao D, Zhan J, Wang A. De Novo Assembly and Comparative Analysis of Mitochondrial Genomes of Two Pueraria montana Varieties. Int J Mol Sci 2024; 25:5656. [PMID: 38891844 PMCID: PMC11171644 DOI: 10.3390/ijms25115656] [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: 03/07/2024] [Revised: 05/10/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024] Open
Abstract
Pueraria montana is a species with important medicinal value and a complex genetic background. In this study, we sequenced and assembled the mitochondrial (mt) genomes of two varieties of P. montana. The mt genome lengths of P. montana var. thomsonii and P. montana var. montana were 457,390 bp and 456,731 bp, respectively. Both P. montana mitogenomes showed a multi-branched structure consisting of two circular molecules, with 56 genes annotated, comprising 33 protein-coding genes, 18 tRNA genes (trnC-GCA and trnM-CAU are multi-copy genes), and 3 rRNA genes. Then, 207 pairs of long repeats and 96 simple sequence repeats (SSRs) were detected in the mt genomes of P. montana, and 484 potential RNA-editing sites were found across the 33 mitochondrial protein-coding genes of each variety. Additionally, a syntenic sequence analysis showed a high collinearity between the two mt genomes. This work is the first to analyze the mt genomes of P. montana. It can provide information that can be used to analyze the structure of mt genomes of higher plants and provide a foundation for future comparative genomic studies and evolutionary biology research in related species.
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Affiliation(s)
- Lijun Guo
- National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China; (L.G.); (G.L.); (D.X.); (J.Z.)
| | - Guoren Lao
- National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China; (L.G.); (G.L.); (D.X.); (J.Z.)
| | - Longfei He
- Agricultural and Animal Husbandry Industry Development Research Institute, Guangxi University, Nanning 530004, China;
- Key Laboratory for Agro-Environment and Agro-Product Safety, Guangxi University, Nanning 530004, China
- Key Laboratory of Crop Cultivation and Tillage, Guangxi University, Nanning 530004, China
| | - Dong Xiao
- National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China; (L.G.); (G.L.); (D.X.); (J.Z.)
- Key Laboratory for Agro-Environment and Agro-Product Safety, Guangxi University, Nanning 530004, China
- Key Laboratory of Crop Cultivation and Tillage, Guangxi University, Nanning 530004, China
| | - Jie Zhan
- National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China; (L.G.); (G.L.); (D.X.); (J.Z.)
- Key Laboratory for Agro-Environment and Agro-Product Safety, Guangxi University, Nanning 530004, China
- Key Laboratory of Crop Cultivation and Tillage, Guangxi University, Nanning 530004, China
| | - Aiqin Wang
- National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China; (L.G.); (G.L.); (D.X.); (J.Z.)
- Key Laboratory for Agro-Environment and Agro-Product Safety, Guangxi University, Nanning 530004, China
- Key Laboratory of Crop Cultivation and Tillage, Guangxi University, Nanning 530004, China
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19
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Burr SP, Chinnery PF. Origins of tissue and cell-type specificity in mitochondrial DNA (mtDNA) disease. Hum Mol Genet 2024; 33:R3-R11. [PMID: 38779777 PMCID: PMC11112380 DOI: 10.1093/hmg/ddae059] [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: 12/21/2023] [Revised: 12/21/2023] [Accepted: 02/05/2024] [Indexed: 05/25/2024] Open
Abstract
Mutations of mitochondrial (mt)DNA are a major cause of morbidity and mortality in humans, accounting for approximately two thirds of diagnosed mitochondrial disease. However, despite significant advances in technology since the discovery of the first disease-causing mtDNA mutations in 1988, the comprehensive diagnosis and treatment of mtDNA disease remains challenging. This is partly due to the highly variable clinical presentation linked to tissue-specific vulnerability that determines which organs are affected. Organ involvement can vary between different mtDNA mutations, and also between patients carrying the same disease-causing variant. The clinical features frequently overlap with other non-mitochondrial diseases, both rare and common, adding to the diagnostic challenge. Building on previous findings, recent technological advances have cast further light on the mechanisms which underpin the organ vulnerability in mtDNA diseases, but our understanding is far from complete. In this review we explore the origins, current knowledge, and future directions of research in this area.
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Affiliation(s)
- Stephen P Burr
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0QQ, United Kingdom
| | - Patrick F Chinnery
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
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20
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Zong Y, Li H, Liao P, Chen L, Pan Y, Zheng Y, Zhang C, Liu D, Zheng M, Gao J. Mitochondrial dysfunction: mechanisms and advances in therapy. Signal Transduct Target Ther 2024; 9:124. [PMID: 38744846 PMCID: PMC11094169 DOI: 10.1038/s41392-024-01839-8] [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: 02/13/2023] [Revised: 12/05/2023] [Accepted: 04/21/2024] [Indexed: 05/16/2024] Open
Abstract
Mitochondria, with their intricate networks of functions and information processing, are pivotal in both health regulation and disease progression. Particularly, mitochondrial dysfunctions are identified in many common pathologies, including cardiovascular diseases, neurodegeneration, metabolic syndrome, and cancer. However, the multifaceted nature and elusive phenotypic threshold of mitochondrial dysfunction complicate our understanding of their contributions to diseases. Nonetheless, these complexities do not prevent mitochondria from being among the most important therapeutic targets. In recent years, strategies targeting mitochondrial dysfunction have continuously emerged and transitioned to clinical trials. Advanced intervention such as using healthy mitochondria to replenish or replace damaged mitochondria, has shown promise in preclinical trials of various diseases. Mitochondrial components, including mtDNA, mitochondria-located microRNA, and associated proteins can be potential therapeutic agents to augment mitochondrial function in immunometabolic diseases and tissue injuries. Here, we review current knowledge of mitochondrial pathophysiology in concrete examples of common diseases. We also summarize current strategies to treat mitochondrial dysfunction from the perspective of dietary supplements and targeted therapies, as well as the clinical translational situation of related pharmacology agents. Finally, this review discusses the innovations and potential applications of mitochondrial transplantation as an advanced and promising treatment.
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Affiliation(s)
- Yao Zong
- Centre for Orthopaedic Research, Medical School, The University of Western Australia, Nedlands, WA, 6009, Australia
| | - Hao Li
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
- Institute of Microsurgery on Extremities, and Department of Orthopedic Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Peng Liao
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
- Institute of Microsurgery on Extremities, and Department of Orthopedic Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Long Chen
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yao Pan
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Yongqiang Zheng
- Sixth People's Hospital Fujian, No. 16, Luoshan Section, Jinguang Road, Luoshan Street, Jinjiang City, Quanzhou, Fujian, China
| | - Changqing Zhang
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Delin Liu
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
- Institute of Microsurgery on Extremities, and Department of Orthopedic Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
| | - Minghao Zheng
- Centre for Orthopaedic Research, Medical School, The University of Western Australia, Nedlands, WA, 6009, Australia.
| | - Junjie Gao
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
- Institute of Microsurgery on Extremities, and Department of Orthopedic Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
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21
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Pasqualotto BA, Nelson A, Deheshi S, Sheldon CA, Vogl AW, Rintoul GL. Impaired mitochondrial morphological plasticity and failure of mitophagy associated with the G11778A mutation of LHON. Biochem Biophys Res Commun 2024; 721:150119. [PMID: 38768545 DOI: 10.1016/j.bbrc.2024.150119] [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: 03/04/2024] [Revised: 05/07/2024] [Accepted: 05/13/2024] [Indexed: 05/22/2024]
Abstract
Mitochondrial dynamics were examined in human dermal fibroblasts biopsied from a confirmed Leber's Hereditary Optic Neuropathy (LHON) patient with a homoplasmic G11778A mutation of the mitochondrial genome. Expression of the G11778A mutation did not impart any discernible difference in mitochondrial network morphology using widefield fluorescence microscopy. However, at the ultrastructural level, cells expressing this mutation exhibited an impairment of mitochondrial morphological plasticity when forced to utilize oxidative phosphorylation (OXPHOS) by transition to glucose-free, galactose-containing media. LHON fibroblasts also displayed a transient increase in mitophagy upon transition to galactose media. These results provide new insights into the consequences of the G11778A mutation of LHON and the pathological mechanisms underlying this disease.
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Affiliation(s)
- Bryce A Pasqualotto
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada
| | - Alexa Nelson
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada
| | - Samineh Deheshi
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada
| | - Claire A Sheldon
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Canada
| | - A Wayne Vogl
- Life Sciences Institute and the Department of Cellular & Physiological Sciences, University of British Columbia, Canada
| | - Gordon L Rintoul
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada.
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22
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Gilkerson R, Kaur H, Carrillo O, Ramos I. OMA1-Mediated Mitochondrial Dynamics Balance Organellar Homeostasis Upstream of Cellular Stress Responses. Int J Mol Sci 2024; 25:4566. [PMID: 38674151 PMCID: PMC11049825 DOI: 10.3390/ijms25084566] [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: 03/29/2024] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024] Open
Abstract
In response to cellular metabolic and signaling cues, the mitochondrial network employs distinct sets of membrane-shaping factors to dynamically modulate organellar structures through a balance of fission and fusion. While these organellar dynamics mediate mitochondrial structure/function homeostasis, they also directly impact critical cell-wide signaling pathways such as apoptosis, autophagy, and the integrated stress response (ISR). Mitochondrial fission is driven by the recruitment of the cytosolic dynamin-related protein-1 (DRP1), while fusion is carried out by mitofusins 1 and 2 (in the outer membrane) and optic atrophy-1 (OPA1) in the inner membrane. This dynamic balance is highly sensitive to cellular stress; when the transmembrane potential across the inner membrane (Δψm) is lost, fusion-active OPA1 is cleaved by the overlapping activity with m-AAA protease-1 (OMA1 metalloprotease, disrupting mitochondrial fusion and leaving dynamin-related protein-1 (DRP1)-mediated fission unopposed, thus causing the collapse of the mitochondrial network to a fragmented state. OMA1 is a unique regulator of stress-sensitive homeostatic mitochondrial balance, acting as a key upstream sensor capable of priming the cell for apoptosis, autophagy, or ISR signaling cascades. Recent evidence indicates that higher-order macromolecular associations within the mitochondrial inner membrane allow these specialized domains to mediate crucial organellar functionalities.
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Affiliation(s)
- Robert Gilkerson
- School of Integrative Biological & Chemical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA; (H.K.); (O.C.)
- Department of Health & Biomedical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA
| | - Harpreet Kaur
- School of Integrative Biological & Chemical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA; (H.K.); (O.C.)
| | - Omar Carrillo
- School of Integrative Biological & Chemical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA; (H.K.); (O.C.)
| | - Isaiah Ramos
- School of Integrative Biological & Chemical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA; (H.K.); (O.C.)
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23
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Chen L, Dong X, Huang H, Xu H, Rono PC, Cai X, Hu G. Assembly and comparative analysis of the initial complete mitochondrial genome of Primulina hunanensis (Gesneriaceae): a cave-dwelling endangered plant. BMC Genomics 2024; 25:322. [PMID: 38561677 PMCID: PMC10983754 DOI: 10.1186/s12864-024-10247-9] [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: 12/30/2023] [Accepted: 03/22/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Primulina hunanensis, a troglobitic plant within the Primulina genus of Gesneriaceae family, exhibits robust resilience to arid conditions and holds great horticultural potential as an ornamental plant. The work of chloroplast genome (cpDNA) has been recently accomplished, however, the mitochondrial genome (mtDNA) that is crucial for plant evolution has not been reported. RESULTS In this study, we sequenced and assembled the P. hunanensis complete mtDNA, and elucidated its evolutionary and phylogenetic relationships. The assembled mtDNA spans 575,242 bp with 43.54% GC content, encompassing 60 genes, including 37 protein-coding genes (PCGs), 20 tRNA genes, and 3 rRNA genes. Notably, high number of repetitive sequences in the mtDNA and substantial sequence translocation from chloroplasts to mitochondria were observed. To determine the evolutionary and taxonomic positioning of P. hunanensis, a phylogenetic tree was constructed using mitochondrial PCGs from P. hunanensis and 32 other taxa. Furthermore, an exploration of PCGs relative synonymous codon usage, identification of RNA editing events, and an investigation of collinearity with closely related species were conducted. CONCLUSIONS This study reports the initial assembly and annotation of P. hunanensis mtDNA, contributing to the limited mtDNA repository for Gesneriaceae plants and advancing our understanding of their evolution for improved utilization and conservation.
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Affiliation(s)
- Lingling Chen
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Xiang Dong
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hang Huang
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Haixia Xu
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Peninah Cheptoo Rono
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Xiuzhen Cai
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
| | - Guangwan Hu
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Hubei Jiangxia Laboratory, Wuhan, 430200, China.
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24
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Karanjia R, Sadun AA. Elamipretide Topical Ophthalmic Solution for the Treatment of Subjects with Leber Hereditary Optic Neuropathy: A Randomized Trial. Ophthalmology 2024; 131:422-433. [PMID: 37923251 DOI: 10.1016/j.ophtha.2023.10.033] [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: 08/03/2023] [Revised: 10/03/2023] [Accepted: 10/17/2023] [Indexed: 11/07/2023] Open
Abstract
PURPOSE This study aimed to assess the safety, tolerability, and potential efficacy of topical elamipretide in patients affected with Leber hereditary optic neuropathy (LHON). DESIGN This phase II, prospective, randomized, vehicle-controlled, single-center clinical trial involved administration of elamipretide 1% topical ophthalmic solution to patients with LHON over a 52-week double-masked treatment period, followed by an open-label extension (OLE) for up to 108 additional weeks of treatment. PARTICIPANTS Twelve patients with LHON were included in this study. Patients aged 18 to 50 years with decreased vision for at least ≥ 1 year and ≤ 10 years, and a genetically confirmed diagnosis of m.11778G>A LHON were eligible for this trial. METHODS For the first 52 weeks of the study, patients were randomized to 1 of 3 groups: elamipretide in both eyes or elamipretide in 1 eye (left eye and right eye were considered separate groups) and vehicle in the other eye, followed by an OLE in which both eyes were treated with elamipretide. MAIN OUTCOME MEASURES The primary outcome measure was assessment of adverse events (AEs) from the administration of topical elamipretide, and the primary efficacy end point was change in best-corrected visual acuity (BCVA). Secondary outcome measures included changes in color vision, visual field mean deviation, and electrophysiological outcomes. RESULTS Elamipretide was well tolerated with the majority of AEs being mild to moderate and resolving spontaneously. The change from baseline in BCVA in elamipretide-treated eyes was not significantly different from the vehicle eyes at any time point. Six of 12 subjects met the criteria for clinically relevant benefit (CRB). In the post hoc analysis, change from baseline in mean deviation in the central visual field was significantly greater in elamipretide-treated eyes versus the vehicle eyes. Compared with baseline, both treatment groups showed improvement in color discrimination and contrast sensitivity in the OLE. CONCLUSIONS Elamipretide treatment was generally well tolerated, with no serious AEs reported. Although this study did not meet its primary BCVA efficacy end point, improvements across assessments on visual function during the OLE and the post hoc findings of the Humphrey automated visual field central region were encouraging and require further exploration. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
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Affiliation(s)
- Rustum Karanjia
- Doheny Eye Centers UCLA, Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California; Doheny Eye Institute, Los Angeles, California; Department of Ophthalmology, Universtiy of Ottawa, Ottawa, Canada; Ottawa Eye Institute, The Otawa Hospital, Ottawa, Canada.
| | - Alfredo A Sadun
- Doheny Eye Centers UCLA, Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California; Doheny Eye Institute, Los Angeles, California
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25
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Edmands S. Mother's Curse effects on lifespan and aging. FRONTIERS IN AGING 2024; 5:1361396. [PMID: 38523670 PMCID: PMC10957651 DOI: 10.3389/fragi.2024.1361396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Accepted: 02/20/2024] [Indexed: 03/26/2024]
Abstract
The Mother's Curse hypothesis posits that mothers curse their sons with harmful mitochondria, because maternal mitochondrial inheritance makes selection blind to mitochondrial mutations that harm only males. As a result, mitochondrial function may be evolutionarily optimized for females. This is an attractive explanation for ubiquitous sex differences in lifespan and aging, given the prevalence of maternal mitochondrial inheritance and the established relationship between mitochondria and aging. This review outlines patterns expected under the hypothesis, and traits most likely to be affected, chiefly those that are sexually dimorphic and energy intensive. A survey of the literature shows that evidence for Mother's Curse is limited to a few taxonomic groups, with the strongest support coming from experimental crosses in Drosophila. Much of the evidence comes from studies of fertility, which is expected to be particularly vulnerable to male-harming mitochondrial mutations, but studies of lifespan and aging also show evidence of Mother's Curse effects. Despite some very compelling studies supporting the hypothesis, the evidence is quite patchy overall, with contradictory results even found for the same traits in the same taxa. Reasons for this scarcity of evidence are discussed, including nuclear compensation, factors opposing male-specific mutation load, effects of interspecific hybridization, context dependency and demographic effects. Mother's Curse effects may indeed contribute to sex differences, but the complexity of other contributing factors make Mother's Curse a poor general predictor of sex-specific lifespan and aging.
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Affiliation(s)
- Suzanne Edmands
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
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26
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Yi Z, Zhang X, Tang W, Yu Y, Wei X, Zhang X, Wei W. Strand-selective base editing of human mitochondrial DNA using mitoBEs. Nat Biotechnol 2024; 42:498-509. [PMID: 37217751 PMCID: PMC10940147 DOI: 10.1038/s41587-023-01791-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 04/13/2023] [Indexed: 05/24/2023]
Abstract
A number of mitochondrial diseases in humans are caused by point mutations that could be corrected by base editors, but delivery of CRISPR guide RNAs into the mitochondria is difficult. In this study, we present mitochondrial DNA base editors (mitoBEs), which combine a transcription activator-like effector (TALE)-fused nickase and a deaminase for precise base editing in mitochondrial DNA. Combining mitochondria-localized, programmable TALE binding proteins with the nickase MutH or Nt.BspD6I(C) and either the single-stranded DNA-specific adenine deaminase TadA8e or the cytosine deaminase ABOBEC1 and UGI, we achieve A-to-G or C-to-T base editing with up to 77% efficiency and high specificity. We find that mitoBEs are DNA strand-selective mitochondrial base editors, with editing results more likely to be retained on the nonnicked DNA strand. Furthermore, we correct pathogenic mitochondrial DNA mutations in patient-derived cells by delivering mitoBEs encoded in circular RNAs. mitoBEs offer a precise, efficient DNA editing tool with broad applicability for therapy in mitochondrial genetic diseases.
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Affiliation(s)
- Zongyi Yi
- Biomedical Pioneering Innovation Center, Peking-Tsinghua Center for Life Sciences, Peking University Genome Editing Research Center, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China
- Changping Laboratory, Beijing, P.R. China
| | - Xiaoxue Zhang
- Biomedical Pioneering Innovation Center, Peking-Tsinghua Center for Life Sciences, Peking University Genome Editing Research Center, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, P.R. China
| | - Wei Tang
- Biomedical Pioneering Innovation Center, Peking-Tsinghua Center for Life Sciences, Peking University Genome Editing Research Center, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, P.R. China
| | - Ying Yu
- Biomedical Pioneering Innovation Center, Peking-Tsinghua Center for Life Sciences, Peking University Genome Editing Research Center, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China
| | - Xiaoxu Wei
- Biomedical Pioneering Innovation Center, Peking-Tsinghua Center for Life Sciences, Peking University Genome Editing Research Center, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, P.R. China
| | - Xue Zhang
- Changping Laboratory, Beijing, P.R. China
| | - Wensheng Wei
- Biomedical Pioneering Innovation Center, Peking-Tsinghua Center for Life Sciences, Peking University Genome Editing Research Center, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China.
- Changping Laboratory, Beijing, P.R. China.
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27
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Spinazzola A, Perez-Rodriguez D, Ježek J, Holt IJ. Mitochondrial DNA competition: starving out the mutant genome. Trends Pharmacol Sci 2024; 45:225-242. [PMID: 38402076 DOI: 10.1016/j.tips.2024.01.011] [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: 09/24/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 02/26/2024]
Abstract
High levels of pathogenic mitochondrial DNA (mtDNA) variants lead to severe genetic diseases, and the accumulation of such mutants may also contribute to common disorders. Thus, selecting against these mutants is a major goal in mitochondrial medicine. Although mutant mtDNA can drift randomly, mounting evidence indicates that active forces play a role in the selection for and against mtDNA variants. The underlying mechanisms are beginning to be clarified, and recent studies suggest that metabolic cues, including fuel availability, contribute to shaping mtDNA heteroplasmy. In the context of pathological mtDNAs, remodeling of nutrient metabolism supports mitochondria with deleterious mtDNAs and enables them to outcompete functional variants owing to a replicative advantage. The elevated nutrient requirement represents a mutant Achilles' heel because small molecules that restrict nutrient consumption or interfere with nutrient sensing can purge cells of deleterious mtDNAs and restore mitochondrial respiration. These advances herald the dawn of a new era of small-molecule therapies to counteract pathological mtDNAs.
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Affiliation(s)
- Antonella Spinazzola
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK.
| | - Diego Perez-Rodriguez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| | - Jan Ježek
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| | - Ian J Holt
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK; Biodonostia Health Research Institute, 20014 San Sebastián, Spain; IKERBASQUE (Basque Foundation for Science), 48013 Bilbao, Spain; CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), 28031 Madrid, Spain; Universidad de País Vasco, Barrio Sarriena s/n, 48940 Leioa, Bilbao, Spain.
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28
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Nogueira C, Pereira C, Silva L, Laranjeira M, Lopes A, Neiva R, Rodrigues E, Campos T, Martins E, Bandeira A, Coelho M, Magalhães M, Damásio J, Gaspar A, Janeiro P, Gomes AL, Ferreira AC, Jacinto S, Vieira JP, Diogo L, Santos H, Mendonça C, Vilarinho L. The genetic landscape of mitochondrial diseases in the next-generation sequencing era: a Portuguese cohort study. Front Cell Dev Biol 2024; 12:1331351. [PMID: 38465286 PMCID: PMC10920333 DOI: 10.3389/fcell.2024.1331351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/30/2024] [Indexed: 03/12/2024] Open
Abstract
Introduction: Rare disorders that are genetically and clinically heterogeneous, such as mitochondrial diseases (MDs), have a challenging diagnosis. Nuclear genes codify most proteins involved in mitochondrial biogenesis, despite all mitochondria having their own DNA. The development of next-generation sequencing (NGS) technologies has revolutionized the understanding of many genes involved in the pathogenesis of MDs. In this new genetic era, using the NGS approach, we aimed to identify the genetic etiology for a suspected MD in a cohort of 450 Portuguese patients. Methods: We examined 450 patients using a combined NGS strategy, starting with the analysis of a targeted mitochondrial panel of 213 nuclear genes, and then proceeding to analyze the whole mitochondrial DNA. Results and Discussion: In this study, we identified disease-related variants in 134 (30%) analyzed patients, 88 with nuclear DNA (nDNA) and 46 with mitochondrial DNA (mtDNA) variants, most of them being pediatric patients (66%), of which 77% were identified in nDNA and 23% in mtDNA. The molecular analysis of this cohort revealed 72 already described pathogenic and 20 novel, probably pathogenic, variants, as well as 62 variants of unknown significance. For this cohort of patients with suspected MDs, the use of a customized gene panel provided a molecular diagnosis in a timely and cost-effective manner. Patients who cannot be diagnosed after this initial approach will be further selected for whole-exome sequencing. Conclusion: As a national laboratory for the study and research of MDs, we demonstrated the power of NGS to achieve a molecular etiology, expanding the mutational spectrum and proposing accurate genetic counseling in this group of heterogeneous diseases without therapeutic options.
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Affiliation(s)
- C. Nogueira
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - C. Pereira
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - L. Silva
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - Mateus Laranjeira
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - A. Lopes
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - R. Neiva
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
| | - E. Rodrigues
- Inherited Metabolic Diseases Reference Centre, São João Hospital University Centre, Porto, Portugal
| | - T. Campos
- Inherited Metabolic Diseases Reference Centre, São João Hospital University Centre, Porto, Portugal
| | - E. Martins
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - A. Bandeira
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - M. Coelho
- Inherited Metabolic Diseases Reference Centre, Santo António Hospital University Centre, Porto, Portugal
| | - M. Magalhães
- Neurology Department, Santo António Hospital University Centre, Porto, Portugal
| | - J. Damásio
- Neurology Department, Santo António Hospital University Centre, Porto, Portugal
| | - A. Gaspar
- Inherited Metabolic Diseases Reference Centre, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - P Janeiro
- Inherited Metabolic Diseases Reference Centre, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - A. Levy Gomes
- Neurology Department, Lisboa Norte Hospital University Centre, Lisboa, Portugal
| | - A. C. Ferreira
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - S. Jacinto
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - J. P. Vieira
- Inherited Metabolic Diseases Reference Centre, Lisboa Central Hospital Centre, Lisboa, Portugal
| | - L. Diogo
- Inherited Metabolic Diseases Reference Centre, Coimbra Hospital and University Centre, Coimbra, Portugal
| | - H. Santos
- Inherited Metabolic Diseases Reference Centre, Vila Nova de Gaia Hospital Centre, Vila Nova de Gaia, Portugal
| | - C. Mendonça
- Pediatric Department, Faro Hospital and University Centre, Faro, Portugal
| | - L. Vilarinho
- Research & Development Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
- Newborn Screening, Metabolism & Genetics Unit, Human Genetics Department, National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal
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Omidsalar AA, McCullough CG, Xu L, Boedijono S, Gerke D, Webb MG, Manojlovic Z, Sequeira A, Lew MF, Santorelli M, Serrano GE, Beach TG, Limon A, Vawter MP, Hjelm BE. Common mitochondrial deletions in RNA-Seq: evaluation of bulk, single-cell, and spatial transcriptomic datasets. Commun Biol 2024; 7:200. [PMID: 38368460 PMCID: PMC10874445 DOI: 10.1038/s42003-024-05877-4] [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: 03/15/2023] [Accepted: 01/31/2024] [Indexed: 02/19/2024] Open
Abstract
Common mitochondrial DNA (mtDNA) deletions are large structural variants in the mitochondrial genome that accumulate in metabolically active tissues with age and have been investigated in various diseases. We applied the Splice-Break2 pipeline (designed for high-throughput quantification of mtDNA deletions) to human RNA-Seq datasets and describe the methodological considerations for evaluating common deletions in bulk, single-cell, and spatial transcriptomics datasets. A robust evaluation of 1570 samples from 14 RNA-Seq studies showed: (i) the abundance of some common deletions detected in PCR-amplified mtDNA correlates with levels observed in RNA-Seq data; (ii) RNA-Seq library preparation method has a strong effect on deletion detection; (iii) deletions had a significant, positive correlation with age in brain and muscle; (iv) deletions were enriched in cortical grey matter, specifically in layers 3 and 5; and (v) brain regions with dopaminergic neurons (i.e., substantia nigra, ventral tegmental area, and caudate nucleus) had remarkable enrichment of common mtDNA deletions.
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Affiliation(s)
- Audrey A Omidsalar
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Carmel G McCullough
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Lili Xu
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Stanley Boedijono
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Daniel Gerke
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Michelle G Webb
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Zarko Manojlovic
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Adolfo Sequeira
- Department of Psychiatry and Human Behavior, University of California - Irvine (UCI) School of Medicine, Irvine, CA, USA
| | - Mark F Lew
- Department of Neurology, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Marco Santorelli
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Geidy E Serrano
- Banner Sun Health Research Institute (BSHRI), Sun City, AZ, USA
| | - Thomas G Beach
- Banner Sun Health Research Institute (BSHRI), Sun City, AZ, USA
| | - Agenor Limon
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, School of Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Marquis P Vawter
- Department of Psychiatry and Human Behavior, University of California - Irvine (UCI) School of Medicine, Irvine, CA, USA
| | - Brooke E Hjelm
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA.
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30
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Beecher G, Gavrilova RH, Mandrekar J, Naddaf E. Mitochondrial myopathies diagnosed in adulthood: clinico-genetic spectrum and long-term outcomes. Brain Commun 2024; 6:fcae041. [PMID: 38434220 PMCID: PMC10906953 DOI: 10.1093/braincomms/fcae041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 12/14/2023] [Accepted: 02/12/2024] [Indexed: 03/05/2024] Open
Abstract
Mitochondrial myopathies are frequently recognized in childhood as part of a broader multisystem disorder and often overlooked in adulthood. Herein, we describe the phenotypic and genotypic spectrum and long-term outcomes of mitochondrial myopathies diagnosed in adulthood, focusing on neuromuscular features, electrodiagnostic and myopathological findings and survival. We performed a retrospective chart review of adult patients diagnosed with mitochondrial myopathy at Mayo Clinic (2005-21). We identified 94 patients. Median time from symptom onset to diagnosis was 11 years (interquartile range 4-21 years). Median age at diagnosis was 48 years (32-63 years). Primary genetic defects were identified in mitochondrial DNA in 48 patients (10 with single large deletion, 38 with point mutations) and nuclear DNA in 29. Five patients had multiple mitochondrial DNA deletions or depletion without nuclear DNA variants. Twelve patients had histopathological features of mitochondrial myopathy without molecular diagnosis. The most common phenotypes included multisystem disorder (n = 30); mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (14); limb myopathy (13); chronic progressive external ophthalmoplegia (12); and chronic progressive external ophthalmoplegia-plus (12). Isolated skeletal muscle manifestations occurred in 27%. Sixty-nine per cent had CNS and 21% had cardiac involvement. Mutations most frequently involved MT-TL1 (27) and POLG (17); however, a wide spectrum of established and novel molecular defects, with overlapping phenotypes, was identified. Electrodiagnostic studies identified myopathy (77%), fibrillation potentials (27%) and axonal peripheral neuropathy (42%, most common with nuclear DNA variants). Among 42 muscle biopsies available, median percentage counts were highest for cytochrome C oxidase negative fibres (5.1%) then ragged blue (1.4%) and ragged red fibres (0.5%). Skeletal muscle weakness was mild and slowly progressive (decline in strength summated score of 0.01/year). Median time to gait assistance was 5.5 years from diagnosis and 17 years from symptom onset. Thirty patients died, with median survival of 33.4 years from symptom onset and 10.9 years from diagnosis. Median age at death was 55 years. Cardiac involvement was associated with increased mortality [hazard ratio 2.36 (1.05, 5.29)]. There was no difference in survival based on genotype or phenotype. Despite the wide phenotypic and genotypic spectrum, mitochondrial myopathies in adults share similar features with slowly progressive limb weakness, contrasting with common multiorgan involvement and high mortality.
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Affiliation(s)
- Grayson Beecher
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Ralitza H Gavrilova
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Jay Mandrekar
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Elie Naddaf
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
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31
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Aguilar K, Canal C, Comes G, Díaz-Clavero S, Llanos MA, Quintana A, Sanz E, Hidalgo J. Interleukin-6-elicited chronic neuroinflammation may decrease survival but is not sufficient to drive disease progression in a mouse model of Leigh syndrome. J Inflamm (Lond) 2024; 21:1. [PMID: 38212783 PMCID: PMC10782699 DOI: 10.1186/s12950-023-00369-4] [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: 08/10/2023] [Accepted: 12/01/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND Mitochondrial diseases (MDs) are genetic disorders characterized by dysfunctions in mitochondria. Clinical data suggest that additional factors, beyond genetics, contribute to the onset and progression of this group of diseases, but these influencing factors remain largely unknown. Mounting evidence indicates that immune dysregulation or distress could play a role. Clinical observations have described the co-incidence of infection and the onset of the disease as well as the worsening of symptoms following infection. These findings highlight the complex interactions between MDs and immunity and underscore the need to better understand their underlying relationships. RESULTS We used Ndufs4 KO mice, a well-established mouse model of Leigh syndrome (one of the most relevant MDs), to test whether chronic induction of a neuroinflammatory state in the central nervous system before the development of neurological symptoms would affect both the onset and progression of the disease in Ndufs4 KO mice. To this aim, we took advantage of the GFAP-IL6 mouse, which overexpresses interleukin-6 (IL-6) in astrocytes and produces chronic glial reactivity, by generating a mouse line with IL-6 overexpression and NDUFS4 deficiency. IL-6 overexpression aggravated the mortality of female Ndufs4 KO mice but did not alter the main motor and respiratory phenotypes measured in any sex. Interestingly, an abnormal region-dependent microglial response to IL-6 overexpression was observed in Ndufs4 KO mice compared to controls. CONCLUSION Overall, our data indicate that chronic neuroinflammation may worsen the disease in Ndufs4 KO female mice, but not in males, and uncovers an abnormal microglial response due to OXPHOS dysfunction, which may have implications for our understanding of the effect of OXPHOS dysfunction in microglia.
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Affiliation(s)
- Kevin Aguilar
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
- Present address: Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
| | - Carla Canal
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Gemma Comes
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Sandra Díaz-Clavero
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
- Present address: Dementia Research Institute, Imperial College London, London, UK
| | - Maria Angeles Llanos
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Albert Quintana
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Elisenda Sanz
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193.
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
| | - Juan Hidalgo
- Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain, 08193.
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
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32
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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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33
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Wang D, Teng J, Ning C, Wang W, Liu S, Zhang Q, Tang H. Mitogenome-wide association study on body measurement traits of Wenshang Barred chickens. Anim Biotechnol 2023; 34:3154-3161. [PMID: 36282276 DOI: 10.1080/10495398.2022.2137035] [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] [Indexed: 11/01/2022]
Abstract
Mitochondria are best known for synthesizing ATP through the tricarboxylic acid cycle and oxidative phosphorylation. The cytoplasmic mitochondrial DNA (mtDNA) is important for maintaining the function. This study was designed to reveal the effect of mtDNA on chicken body measurement traits (BMTs). A population of 605 Wenshang Barred chickens were recorded BMTs, including body slope length, keel length, chest width, etc. The single-nucleotide polymorphisms (SNPs) of their mitogenomes were detected by PCR amplification and DNA sequencing. Totally 69 mutations in mitogenome were discovered, including 18 in noncoding region and 51 in coding region. By multi-sequence alignment and haplotype construction, the chickens were clustered into eight haplotypes and further three haplogroups. The association between BMTs and mtDNA SNPs, haplotypes and haplogroups were analyzed in the linear model by ASReml, respectively. Among them, the SNP mt11086 T/C in ND3 was found to significantly affect chest dept (p < .05) and was highly conservative by phylogenetic conservation analyses, which reflected the genetic effect on body size and growth of chickens. No significant association between the mitochondrial haplotypes or haplogroups and BMTs was found. The polymorphic site reflecting body size could be put into chicken breeding programs as the genetic marker.
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Affiliation(s)
- Dan Wang
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Jun Teng
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Chao Ning
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Wenwen Wang
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Shuai Liu
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Qin Zhang
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Hui Tang
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, China
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34
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Burke PJ. How defective mitochondrial electrical activity leads to inherited blindness. Proc Natl Acad Sci U S A 2023; 120:e2315649120. [PMID: 37878684 PMCID: PMC10636301 DOI: 10.1073/pnas.2315649120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023] Open
Affiliation(s)
- Peter J. Burke
- Department of Electrical Engineering and Computer Science, University of California, Irvine, CA92697
- Department of Biomedical Engineering, University of California, Irvine, CA92697
- Department of Chemical and Biomolecular Engineering, University of California, Irvine, CA92697
- Department of Materials Science and Engineering, University of California, Irvine, CA92697
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35
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Nieto-Panqueva F, Rubalcava-Gracia D, Hamel PP, González-Halphen D. The constraints of allotopic expression. Mitochondrion 2023; 73:30-50. [PMID: 37739243 DOI: 10.1016/j.mito.2023.09.004] [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: 01/19/2023] [Revised: 08/28/2023] [Accepted: 09/18/2023] [Indexed: 09/24/2023]
Abstract
Allotopic expression is the functional transfer of an organellar gene to the nucleus, followed by synthesis of the gene product in the cytosol and import into the appropriate organellar sub compartment. Here, we focus on mitochondrial genes encoding OXPHOS subunits that were naturally transferred to the nucleus, and critically review experimental evidence that claim their allotopic expression. We emphasize aspects that may have been overlooked before, i.e., when modifying a mitochondrial gene for allotopic expression━besides adapting the codon usage and including sequences encoding mitochondrial targeting signals━three additional constraints should be considered: (i) the average apparent free energy of membrane insertion (μΔGapp) of the transmembrane stretches (TMS) in proteins earmarked for the inner mitochondrial membrane, (ii) the final, functional topology attained by each membrane-bound OXPHOS subunit; and (iii) the defined mechanism by which the protein translocator TIM23 sorts cytosol-synthesized precursors. The mechanistic constraints imposed by TIM23 dictate the operation of two pathways through which alpha-helices in TMS are sorted, that eventually determine the final topology of membrane proteins. We used the biological hydrophobicity scale to assign an average apparent free energy of membrane insertion (μΔGapp) and a "traffic light" color code to all TMS of OXPHOS membrane proteins, thereby predicting which are more likely to be internalized into mitochondria if allotopically produced. We propose that the design of proteins for allotopic expression must make allowance for μΔGapp maximization of highly hydrophobic TMS in polypeptides whose corresponding genes have not been transferred to the nucleus in some organisms.
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Affiliation(s)
- Felipe Nieto-Panqueva
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Diana Rubalcava-Gracia
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico; Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Patrice P Hamel
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH, USA; Vellore Institute of Technology (VIT), School of BioScience and Technology, Vellore, Tamil Nadu, India
| | - Diego González-Halphen
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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36
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Chermakani P, Gowri P, Mahesh Kumar S, Sundaresan P. Exploring mito-nuclear genetic factors in Leber's hereditary optic neuropathy: insights from comprehensive profiling of unique cases. EXCLI JOURNAL 2023; 22:1077-1091. [PMID: 38054206 PMCID: PMC10694345 DOI: 10.17179/excli2023-6297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/06/2023] [Indexed: 12/07/2023]
Abstract
Leber's hereditary optic neuropathy (LHON) is a mitochondrial complex I disorder and causes inexorable painless vision loss. Recent studies from India reported that a significant proportion of LHON patients lack primary mitochondrial DNA mutations, suggesting that alternative genetic factors contribute to disease development. Therefore, this study investigated the genetic profile of LHON-affected individuals in order to understand the role of mito-nuclear genetic factors in LHON. A total of thirty probands displaying symptoms consistent with LHON have undergone whole mitochondrial and whole exome sequencing. Interestingly, whole mtDNA sequencing revealed primary mtDNA mutations in 30 % of the probands (n=9), secondary mtDNA mutations in 40 % of the probands (n=12) and no mitochondrial changes in 30 % of individuals (n=9). Further, WES analysis determined pathogenic mutations in 11 different nuclear genes, especially in cases with secondary mtDNA mutations (n=6) or no mtDNA mutations (n=6). These findings provide valuable insight into LHON genetic predisposition, particularly in cases lacking primary mtDNA mutations. See also Figure 1(Fig. 1).
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Affiliation(s)
- Prakash Chermakani
- Department of Molecular Genetics, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
- Department of Molecular Biology, Aravind Medical Research Foundation - Affiliated to Alagappa University, Karaikudi, Tamil Nadu, India
| | - Poigaialwar Gowri
- Department of Molecular Genetics, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
- Department of Molecular Biology, Aravind Medical Research Foundation - Affiliated to Alagappa University, Karaikudi, Tamil Nadu, India
| | | | - Periasamy Sundaresan
- Department of Molecular Genetics, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
- Department of Molecular Biology, Aravind Medical Research Foundation - Affiliated to Alagappa University, Karaikudi, Tamil Nadu, India
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37
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Hong YS, Battle SL, Shi W, Puiu D, Pillalamarri V, Xie J, Pankratz N, Lake NJ, Lek M, Rotter JI, Rich SS, Kooperberg C, Reiner AP, Auer PL, Heard-Costa N, Liu C, Lai M, Murabito JM, Levy D, Grove ML, Alonso A, Gibbs R, Dugan-Perez S, Gondek LP, Guallar E, Arking DE. Deleterious heteroplasmic mitochondrial mutations are associated with an increased risk of overall and cancer-specific mortality. Nat Commun 2023; 14:6113. [PMID: 37777527 PMCID: PMC10542802 DOI: 10.1038/s41467-023-41785-7] [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: 05/14/2023] [Accepted: 09/14/2023] [Indexed: 10/02/2023] Open
Abstract
Mitochondria carry their own circular genome and disruption of the mitochondrial genome is associated with various aging-related diseases. Unlike the nuclear genome, mitochondrial DNA (mtDNA) can be present at 1000 s to 10,000 s copies in somatic cells and variants may exist in a state of heteroplasmy, where only a fraction of the DNA molecules harbors a particular variant. We quantify mtDNA heteroplasmy in 194,871 participants in the UK Biobank and find that heteroplasmy is associated with a 1.5-fold increased risk of all-cause mortality. Additionally, we functionally characterize mtDNA single nucleotide variants (SNVs) using a constraint-based score, mitochondrial local constraint score sum (MSS) and find it associated with all-cause mortality, and with the prevalence and incidence of cancer and cancer-related mortality, particularly leukemia. These results indicate that mitochondria may have a functional role in certain cancers, and mitochondrial heteroplasmic SNVs may serve as a prognostic marker for cancer, especially for leukemia.
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Affiliation(s)
- Yun Soo Hong
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Stephanie L Battle
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Natural Sciences, College of Arts and Sciences, Bowie State University, Bowie, MD, USA
| | - Wen Shi
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniela Puiu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Vamsee Pillalamarri
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jiaqi Xie
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nathan Pankratz
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | - Nicole J Lake
- Department of Genetics, Yale School of Medicine, New Haven, CT, USA
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia
| | - Monkol Lek
- Department of Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Jerome I Rotter
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Stephen S Rich
- Center for Public Health Genomics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
| | - Charles Kooperberg
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Alex P Reiner
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Paul L Auer
- Division of Biostatistics, Institute for Health & Equity, and Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Nancy Heard-Costa
- Departments of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
- Framingham Heart Study, Framingham, MA, USA
| | - Chunyu Liu
- Framingham Heart Study, Framingham, MA, USA
- Department of Biostatistics, School of Public Health, Boston University, Boston, MA, USA
| | - Meng Lai
- Department of Biostatistics, School of Public Health, Boston University, Boston, MA, USA
| | - Joanne M Murabito
- Section of General Internal Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Daniel Levy
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Megan L Grove
- Human Genetics Center; Department of Epidemiology, Human Genetics, and Environmental Sciences; School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Alvaro Alonso
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Richard Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Shannon Dugan-Perez
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Lukasz P Gondek
- Division of Hematological Malignancies, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, USA
| | - Eliseo Guallar
- Department of Epidemiology and Medicine, and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Dan E Arking
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Baltă G, Cristache G, Barac AD, Anton N, Barac IR. Leber's Hereditary Optic Neuropathy (LHON): Clinical Experience and Outcomes after Long-Term Idebenone Treatment. Life (Basel) 2023; 13:2000. [PMID: 37895381 PMCID: PMC10608457 DOI: 10.3390/life13102000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) is a rare disease. Large studies are difficult to conduct; therefore, case reports provide valuable data. Since 2015, patients have been treated with Idebenone. The aim of this paper is to share our experience with diagnosing and managing patients in different stages of LHON. METHODS We designed a case series study, including four patients undergoing genetic testing and ophthalmologic examination. Criteria for Idebenone administration and follow-up were presented. RESULTS All patients had mutation 11778G>A in MT-ND4. The first patient, an 82-year-old man, with long history of vision loss, had no indication for Idebenone. Two additional cases emerged within the same family: a 40-year-old brother and a 31-year-old sister. Both received Idebenone, with good outcomes only for the female. After a one-year regimen, they were lost to follow-up. The fourth patient, a 46-year-old man, was diagnosed in the subacute stage. Idebenone administration was deferred, allowing progression of visual field defects. After 17 months of treatment, visual improvement appeared. The treatment was continued for 36 months, with short interruptions, resulting in good outcomes. CONCLUSIONS Our study demonstrated positive results with long-term Idebenone use. Contrary to medical literature, our female patient had a favorable evolution, despite the delayed diagnosis.
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Affiliation(s)
- George Baltă
- Doctoral School, University of Medicine and Pharmacy “Carol Davila” Bucharest, 050474 Bucharest, Romania;
| | - Georgiana Cristache
- Doctoral School, University of Medicine and Pharmacy “Carol Davila” Bucharest, 050474 Bucharest, Romania;
| | - Andreea Diana Barac
- Faculty of Medicine, University of Medicine and Pharmacy “Carol Davila” Bucharest, 050474 Bucharest, Romania;
| | - Nicoleta Anton
- Department of Ophthalmology, University of Medicine and Pharmacy “Grigore T. Popa” Iasi, 700115 Iasi, Romania;
| | - Ileana Ramona Barac
- Department of Ophthalmology, University of Medicine and Pharmacy “Carol Davila” Bucharest, 050474 Bucharest, Romania;
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Czarny P, Ziółkowska S, Kołodziej Ł, Watała C, Wigner-Jeziorska P, Bliźniewska-Kowalska K, Wachowska K, Gałecka M, Synowiec E, Gałecki P, Bijak M, Szemraj J, Śliwiński T. Single-Nucleotide Polymorphisms in Genes Maintaining the Stability of Mitochondrial DNA Affect the Occurrence, Onset, Severity and Treatment of Major Depressive Disorder. Int J Mol Sci 2023; 24:14752. [PMID: 37834200 PMCID: PMC10573273 DOI: 10.3390/ijms241914752] [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: 09/02/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
One of the key features of major depressive disorder (MDD, depression) is increased oxidative stress manifested by elevated levels of mtROS, a hallmark of mitochondrial dysfunction, which can arise from mitochondrial DNA (mtDNA) damage. Thus, the current study explores possibility that the single-nucleotide polymorphisms (SNPs) of genes encoding the three enzymes that are thought to be implicated in the replication, repair or degradation of mtDNA, i.e., POLG, ENDOG and EXOG, have an impact on the occurrence, onset, severity and treatment of MDD. Five SNPs were selected: EXOG c.-188T > G (rs9838614), EXOG c.*627G > A (rs1065800), POLG c.-1370T > A (rs1054875), ENDOG c.-394T > C (rs2977998) and ENDOG c.-220C > T (rs2997922), while genotyping was performed on 538 DNA samples (277 cases and 261 controls) using TaqMan probes. All SNPs of EXOG and ENDOG modulated the risk of depression, but the strongest effect was observed for rs1065800, while rs9838614 and rs2977998 indicate that they might influence the severity of symptoms, and, to a lesser extent, treatment effectiveness. Although the SNP located in POLG did not affect occurrence of the disease, the result suggests that it may influence the onset and treatment outcome. These findings further support the hypothesis that mtDNA damage and impairment in its metabolism play a crucial role not only in the development, but also in the treatment of depression.
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Affiliation(s)
- Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (S.Z.); (J.S.)
| | - Sylwia Ziółkowska
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (S.Z.); (J.S.)
| | - Łukasz Kołodziej
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 92-215 Lodz, Poland; (Ł.K.)
| | - Cezary Watała
- Department of Haemostatic Disorders, Medical University of Lodz, 92-215 Lodz, Poland;
| | - Paulina Wigner-Jeziorska
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 90-136 Lodz, Poland;
| | | | - Katarzyna Wachowska
- Department of Adult Psychiatry, Medical University of Lodz, 91-229 Lodz, Poland; (K.B.-K.); (K.W.); (P.G.)
| | - Małgorzata Gałecka
- Department of Psychotherapy, Medical University of Lodz, 91-229 Lodz, Poland;
| | - Ewelina Synowiec
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 92-215 Lodz, Poland; (Ł.K.)
| | - Piotr Gałecki
- Department of Adult Psychiatry, Medical University of Lodz, 91-229 Lodz, Poland; (K.B.-K.); (K.W.); (P.G.)
| | - Michał Bijak
- Biohazard Prevention Centre, Faculty of Biology and Environmental Protection, University of Lodz, 90-136 Lodz, Poland;
| | - Janusz Szemraj
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (S.Z.); (J.S.)
| | - Tomasz Śliwiński
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 92-215 Lodz, Poland; (Ł.K.)
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Fuller JT, Barnes S, Sadun LA, Ajmera P, Alexandrova AN, Sadun AA. Coenzyme Q10 trapping in mitochondrial complex I underlies Leber's hereditary optic neuropathy. Proc Natl Acad Sci U S A 2023; 120:e2304884120. [PMID: 37733737 PMCID: PMC10523484 DOI: 10.1073/pnas.2304884120] [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: 03/27/2023] [Accepted: 06/21/2023] [Indexed: 09/23/2023] Open
Abstract
How does a single amino acid mutation occurring in the blinding disease, Leber's hereditary optic neuropathy (LHON), impair electron shuttling in mitochondria? We investigated changes induced by the m.3460 G>A mutation in mitochondrial protein ND1 using the tools of Molecular Dynamics and Free Energy Perturbation simulations, with the goal of determining the mechanism by which this mutation affects mitochondrial function. A recent analysis suggested that the mutation's replacement of alanine A52 with a threonine perturbs the stability of a region where binding of the electron shuttling protein, Coenzyme Q10, occurs. We found two functionally opposing changes involving the role of Coenzyme Q10. The first showed that quantum electron transfer from the terminal Fe/S complex, N2, to the Coenzyme Q10 headgroup, docked in its binding pocket, is enhanced. However, this positive adjustment is overshadowed by our finding that the mobility of Coenzyme Q10 in its oxidized and reduced states, entering and exiting its binding pocket, is disrupted by the mutation in a manner that leads to conditions promoting the generation of reactive oxygen species. An increase in reactive oxygen species caused by the LHON mutation has been proposed to be responsible for this optic neuropathy.
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Affiliation(s)
- Jack T. Fuller
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Steven Barnes
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Doheny Eye Institute, Pasadena, CA91103
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Lorenzo A. Sadun
- Department of Mathematics, University of Texas at Austin, Austin, TX78712
| | - Pujan Ajmera
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | | | - Alfredo A. Sadun
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Doheny Eye Institute, Pasadena, CA91103
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McDonald HM, Sadikovic B, Sheldon CA, Bursztyn LLCD. Leber Hereditary Optic Neuropathy in Southwestern Ontario: A Growing List of Mutations. Can J Neurol Sci 2023; 50:738-744. [PMID: 35892476 DOI: 10.1017/cjn.2022.279] [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] [Indexed: 11/07/2022]
Abstract
BACKGROUND Leber hereditary optic neuropathy (LHON) is a rare but bilaterally blinding disease. Three characteristic disease-causing point mutations, and other less common mutations, are most often found on the mitochondrially encoded genes of NADH-ubiquinone oxidoreductase core subunits (MT-ND). The purpose of this study is to provide an overview of LHON mutations in Southwestern Ontario and to describe the associated demographic and clinical characteristics. METHODS A retrospective genetic and clinical chart review was performed from January 2015 to 2020. Patients were identified within a mitochondrial mutation database and included if a mutation was detected on the MT-ND1, -ND4, or -ND6 genes. A clinical chart review was done on all available patients. RESULTS Forty-five of 63 patients identified had classic disease-causing mutations (6.7% m.3460G>A, 44.4% m.11778G>A, and 48.9% m.14484T>C). Several of the remaining 18 patients had rare mutations previously documented in association with LHON. Of the 14 patients with clinical charts accessible for review, 12 had symptomatic disease, and all but one had bilateral optic neuropathies. Nine patients had classic LHON mutations and 3 had possible novel mutations; 7 were males; 9 had final visual acuity ≤ 20/200 in at least one eye; and 6 of those had ≤20/400 in both eyes. CONCLUSIONS This study adds to the literature on LHON in Canada, and specifically Southwestern Ontario. The demographic and clinical data regarding LHON in this geographic location, as well as possible novel disease-causing mutations, provide important information to aid clinicians in recognizing cases of LHON that may otherwise be disregarded.
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Affiliation(s)
- Heather M McDonald
- Department of Ophthalmology, University of Western Ontario, London, Ontario, Canada
| | - Bekim Sadikovic
- Pathology and Laboratory Medicine, University of Western Ontario, London, Ontario, Canada
| | - Claire A Sheldon
- Department of Ophthalmology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lulu L C D Bursztyn
- Department of Ophthalmology, University of Western Ontario, London, Ontario, Canada
- Centre for Neuroscience Studies, University of Western Ontario, London, Ontario, Canada
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Battista M, Cascavilla ML, Borrelli E, Barresi C, Lari G, Caporali L, Viganò C, Berni A, Carelli V, Bandello F, Barboni P. Choroidal vascularity index in hereditary optic neuropathies. Eye (Lond) 2023; 37:2679-2684. [PMID: 36747110 PMCID: PMC10482917 DOI: 10.1038/s41433-023-02383-5] [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: 05/05/2022] [Revised: 12/04/2022] [Accepted: 01/10/2023] [Indexed: 02/08/2023] Open
Abstract
PURPOSE To assess the choroidal vascularity index (CVI) in patients affected by Leber hereditary optic neuropathy (LHON) compared to patients affected by dominant optic atrophy (DOA) and healthy subjects. METHODS In this retrospective study, we considered three cohorts: LHON eyes (48), DOA eyes (48) and healthy subjects' eyes (48). All patients underwent a complete ophthalmologic examination, including best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) acquisition. OCT parameters as subfoveal choroidal thickness (Sub-F ChT), mean choroidal thickness (ChT), total choroidal area (TCA), luminal choroidal area (LCA) were calculated. CVI was obtained as the ratio of LCA and TCA. RESULTS Subfoveal ChT in LHON patients did not show statistically significant differences compared to controls, while in DOA a reduction in choroidal thickness was observed (p = 0.344 and p = 0.045, respectively). Mean ChT was reduced in both LHON and DOA subjects, although this difference reached statistical significance only in DOA (p = 0.365 and p = 0.044, respectively). TCA showed no significant differences among the 3 cohorts (p = 0.832). No changes were detected in LCA among the cohorts (p = 0.389), as well as in the stromal choroidal area (SCA, p = 0.279). The CVI showed no differences among groups (p = 0.898): LHON group was characterized by a similar CVI in comparison to controls (p = 0.911) and DOA group (p = 0.818); the DOA group was characterized by a similar CVI in comparison to controls (p = 1.0). CONCLUSION CVI is preserved in DOA and LHON patients, suggesting that even in the chronic phase of the neuropathy the choroidal structure is not irreversibly compromised.
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Affiliation(s)
- Marco Battista
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Lucia Cascavilla
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Enrico Borrelli
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Costanza Barresi
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giorgio Lari
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Chiara Viganò
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessandro Berni
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Francesco Bandello
- Vita-Salute San Raffaele University Milan, Milan, Italy
- IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Piero Barboni
- Vita-Salute San Raffaele University Milan, Milan, Italy.
- IRCCS San Raffaele Scientific Institute, Milan, Italy.
- Studio Oculistico d'Azeglio, Bologna, Italy.
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Shamsnajafabadi H, MacLaren RE, Cehajic-Kapetanovic J. Current and Future Landscape in Genetic Therapies for Leber Hereditary Optic Neuropathy. Cells 2023; 12:2013. [PMID: 37566092 PMCID: PMC10416882 DOI: 10.3390/cells12152013] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023] Open
Abstract
Leber hereditary optic neuropathy (LHON) is the most common primary mitochondrial genetic disease that causes blindness in young adults. Over 50 inherited mitochondrial DNA (mtDNA) variations are associated with LHON; however, more than 95% of cases are caused by one of three missense variations (m.11778 G > A, m.3460 G > A, and m.14484 T > C) encoding for subunits ND4, ND1, and ND6 of the respiration complex I, respectively. These variants remain silent until further and currently poorly understood genetic and environmental factors precipitate the visual loss. The clinical course that ensues is variable, and a convincing treatment for LHON has yet to emerge. In 2015, an antioxidant idebenone (Raxone) received European marketing authorisation to treat visual impairment in patients with LHON, and since then it was introduced into clinical practice in several European countries. Alternative therapeutic strategies, including gene therapy and gene editing, antioxidant and neurotrophic agents, mitochondrial biogenesis, mitochondrial replacement, and stem cell therapies are being investigated in how effective they might be in altering the course of the disease. Allotopic gene therapies are in the most advanced stage of development (phase III clinical trials) whilst most other agents are in phase I or II trials or at pre-clinical stages. This manuscript discusses the phenotype and genotype of the LHON disease with complexities and peculiarities such as incomplete penetrance and gender bias, which have challenged the therapies in development emphasising the most recent use of gene therapy. Furthermore, we review the latest results of the three clinical trials based on adeno-associated viral (AAV) vector-mediated delivery of NADH dehydrogenase subunit 4 (ND4) with mitochondrial targeting sequence, highlighting the differences in the vector design and the rationale behind their use in the allotopic transfer.
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Affiliation(s)
- Hoda Shamsnajafabadi
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, Oxford University, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, Oxford University, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, Oxford University, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
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Wang J, Ji Y, Ai C, Chen JR, Gan D, Zhang J, Mo JQ, Guan MX. Optimized allotopic expression of mitochondrial ND6 transgene restored complex I and apoptosis deficiencies caused by LHON-linked ND6 14484T > C mutation. J Biomed Sci 2023; 30:63. [PMID: 37537557 PMCID: PMC10399063 DOI: 10.1186/s12929-023-00951-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/11/2023] [Indexed: 08/05/2023] Open
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) is a maternally inherited eye disease due to mutations in mitochondrial DNA. However, there is no effective treatment for this disease. LHON-linked ND6 14484T > C (p.M64V) mutation caused complex I deficiency, diminished ATP production, increased production of reactive oxygen species (ROS), elevated apoptosis, and impaired mitophagy. Here, we investigated if the allotopic expression of human mitochondrial ND6 transgene corrected the mitochondrial dysfunctions due to LHON-associated m.14484T > C mutation. METHODS Nucleus-versions of ND6 was generated by changing 6 non-universal codons with universal codons and added to mitochondrial targeting sequence of COX8. Stable transfectants were generated by transferring human ND6 cDNA expressed in a pCDH-puro vector into mutant cybrids carrying the m.14484T > C mutation and control cybrids. The effect of allotopic expression of ND6 on oxidative phosphorylation (OXPHOS) was evaluated using Blue Native gel electrophoresis and extracellular flux analyzer. Assessment of ROS production in cell lines was performed by flow cytometry with MitoSOX Red reagent. Analyses for apoptosis and mitophagy were undertaken via flow cytometry, TUNEL and immunofluorescence assays. RESULTS The transfer of human ND6 into the cybrids carrying the m.14484T > C mutation raised the levels of ND6, ND1 and ND4L but did not change the levels of other mitochondrial proteins. The overexpression of ND6 led to 20~23% increases in the assembly and activity of complex I, and ~ 53% and ~ 33% increases in the levels of mitochondrial ATP and ΔΨm in the mutant cybrids bearing m.14484T > C mutation. Furthermore, mutant cybrids with overexpression of ND6 exhibited marked reductions in the levels of mitochondrial ROS. Strikingly, ND6 overexpression markedly inhibited the apoptosis process and restored impaired mitophagy in the cells carrying m.14484T > C mutation. However, overexpression of ND6 did not affect the ND6 level and mitochondrial functions in the wild-type cybrids, indicating that this ND6 level appeared to be the maximum threshold level to maintain the normal cell function. CONCLUSION We demonstrated that allotopic expression of nucleus-versions of ND6 restored complex I, apoptosis and mitophagy deficiencies caused by the m.14484T > C mutation. The restoration of m.14484T > C mutation-induced mitochondrial dysfunctions by overexpression of ND6 is a step toward therapeutic interventions for LHON and mitochondrial diseases.
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Affiliation(s)
- Jing Wang
- Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang, China
| | - Cheng Ai
- Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang, China
| | - Jia-Rong Chen
- Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang, China
| | - Dingyi Gan
- Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang, China
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jun Q Mo
- Department of Pathology, Rady Children's Hospital, University of California at San Diego School of Medicine, San Diego, California, USA
| | - Min-Xin Guan
- Center for Mitochondrial Biomedicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China.
- Institute of Genetics, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang, China.
- Zhejiang Provincial Key Laboratory of Genetic and Developmental Disorders, Hangzhou, Zhejiang, China.
- Key Lab of Reproductive Genetics, Ministry of Education of PRC, Zhejiang University, Hangzhou, Zhejiang, China.
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Wan X, Chen J, Wu Y, Chen Z, Liu Y, Li T, Sun J, Zhang T, Zhou F, Huang X, Li Y, Wang X, Sun X. Rapid and Sensitive Diagnosis of Leber Hereditary Optic Neuropathy Variants Using CRISPR/Cas12a Detection. J Mol Diagn 2023; 25:540-554. [PMID: 37517824 DOI: 10.1016/j.jmoldx.2023.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 12/08/2022] [Accepted: 04/05/2023] [Indexed: 08/01/2023] Open
Abstract
Leber hereditary optic neuropathy (LHON) is the most common maternally inherited mitochondrial disease, with >90% of cases harboring one of three point variants (m.3460G>A, m.11778G>A, and m.14484T>C). Rapid and sensitive diagnosis of LHON variants is urgently needed for early diagnosis and timely treatment after onset, which is currently limited. Herein, we adapted the Cas12a-based DNA detection platform for LHON mitochondrial variant diagnosis. Single-strand guide CRISPR RNAs and enzymatic recombinase amplification primers were first screened, the CRISPR/Cas12a system was then optimized with restriction enzymes, and finally compared with Sanger sequencing and next-generation sequencing (NGS) in multicenter clinical samples. This approach can be completed within 30 minutes using only one drop of blood and could reach a sensitivity of 1% of heteroplasmy. Among the 182 multicenter clinical samples, the CRISPR/Cas12a detection system showed high consistency with Sanger sequencing and NGS in both specificity and sensitivity. Notably, a sample harboring a de novo 3.78% m.11778G>A variant detected by NGS, but not by Sanger sequencing, was successfully confirmed using the CRISPR/Cas12a assay, which proved the effectiveness of our method. Overall, our CRISPR/Cas12a detection system provides an alternative for rapid, convenient, and sensitive detection of LHON variants, exhibiting great potential for clinical practice.
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Affiliation(s)
- Xiaoling Wan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jieqiong Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yidong Wu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Zhixuan Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yin Liu
- Department of Hematology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Tong Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Junran Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Ting Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Fuling Zhou
- Department of Hematology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xingxu Huang
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yang Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Xinjie Wang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rula Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
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46
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Gupta R, Kanai M, Durham TJ, Tsuo K, McCoy JG, Kotrys AV, Zhou W, Chinnery PF, Karczewski KJ, Calvo SE, Neale BM, Mootha VK. Nuclear genetic control of mtDNA copy number and heteroplasmy in humans. Nature 2023; 620:839-848. [PMID: 37587338 PMCID: PMC10447254 DOI: 10.1038/s41586-023-06426-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 07/11/2023] [Indexed: 08/18/2023]
Abstract
Mitochondrial DNA (mtDNA) is a maternally inherited, high-copy-number genome required for oxidative phosphorylation1. Heteroplasmy refers to the presence of a mixture of mtDNA alleles in an individual and has been associated with disease and ageing. Mechanisms underlying common variation in human heteroplasmy, and the influence of the nuclear genome on this variation, remain insufficiently explored. Here we quantify mtDNA copy number (mtCN) and heteroplasmy using blood-derived whole-genome sequences from 274,832 individuals and perform genome-wide association studies to identify associated nuclear loci. Following blood cell composition correction, we find that mtCN declines linearly with age and is associated with variants at 92 nuclear loci. We observe that nearly everyone harbours heteroplasmic mtDNA variants obeying two principles: (1) heteroplasmic single nucleotide variants tend to arise somatically and accumulate sharply after the age of 70 years, whereas (2) heteroplasmic indels are maternally inherited as mixtures with relative levels associated with 42 nuclear loci involved in mtDNA replication, maintenance and novel pathways. These loci may act by conferring a replicative advantage to certain mtDNA alleles. As an illustrative example, we identify a length variant carried by more than 50% of humans at position chrM:302 within a G-quadruplex previously proposed to mediate mtDNA transcription/replication switching2,3. We find that this variant exerts cis-acting genetic control over mtDNA abundance and is itself associated in-trans with nuclear loci encoding machinery for this regulatory switch. Our study suggests that common variation in the nuclear genome can shape variation in mtCN and heteroplasmy dynamics across the human population.
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Affiliation(s)
- Rahul Gupta
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.
| | - Masahiro Kanai
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Timothy J Durham
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Kristin Tsuo
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Jason G McCoy
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Anna V Kotrys
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Wei Zhou
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Konrad J Karczewski
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Sarah E Calvo
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Benjamin M Neale
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
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47
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Jacobs HT. A century of mitochondrial research, 1922-2022. Enzymes 2023; 54:37-70. [PMID: 37945177 DOI: 10.1016/bs.enz.2023.07.002] [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] [Indexed: 11/12/2023]
Abstract
Although recognized earlier as subcellular entities by microscopists, mitochondria have been the subject of functional studies since 1922, when their biochemical similarities with bacteria were first noted. In this overview I trace the history of research on mitochondria from that time up to the present day, focussing on the major milestones of the overlapping eras of mitochondrial biochemistry, genetics, pathology and cell biology, and its explosion into new areas in the past 25 years. Nowadays, mitochondria are considered to be fully integrated into cell physiology, rather than serving specific functions in isolation.
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Affiliation(s)
- Howard T Jacobs
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Department of Environment and Genetics, La Trobe University, Melbourne, VIC, Australia.
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48
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Hernández CL. Mitochondrial DNA in Human Diversity and Health: From the Golden Age to the Omics Era. Genes (Basel) 2023; 14:1534. [PMID: 37628587 PMCID: PMC10453943 DOI: 10.3390/genes14081534] [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: 06/19/2023] [Revised: 07/21/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Mitochondrial DNA (mtDNA) is a small fraction of our hereditary material. However, this molecule has had an overwhelming presence in scientific research for decades until the arrival of high-throughput studies. Several appealing properties justify the application of mtDNA to understand how human populations are-from a genetic perspective-and how individuals exhibit phenotypes of biomedical importance. Here, I review the basics of mitochondrial studies with a focus on the dawn of the field, analysis methods and the connection between two sides of mitochondrial genetics: anthropological and biomedical. The particularities of mtDNA, with respect to inheritance pattern, evolutionary rate and dependence on the nuclear genome, explain the challenges of associating mtDNA composition and diseases. Finally, I consider the relevance of this single locus in the context of omics research. The present work may serve as a tribute to a tool that has provided important insights into the past and present of humankind.
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Affiliation(s)
- Candela L Hernández
- Department of Biodiversity, Ecology and Evolution, Faculty of Biological Sciences, Complutense University of Madrid, 28040 Madrid, Spain
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49
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Del Giudice L, Pontieri P, Aletta M, Calcagnile M. Mitochondrial Neurodegenerative Diseases: Three Mitochondrial Ribosomal Proteins as Intermediate Stage in the Pathway That Associates Damaged Genes with Alzheimer's and Parkinson's. BIOLOGY 2023; 12:972. [PMID: 37508402 PMCID: PMC10376763 DOI: 10.3390/biology12070972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 07/30/2023]
Abstract
Currently, numerous research endeavors are dedicated to unraveling the intricate nature of neurodegenerative diseases. These conditions are characterized by the gradual and progressive impairment of specific neuronal systems that exhibit anatomical or physiological connections. In particular, in the last twenty years, remarkable efforts have been made to elucidate neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, despite extensive research endeavors, no cure or effective treatment has been discovered thus far. With the emergence of studies shedding light on the contribution of mitochondria to the onset and advancement of mitochondrial neurodegenerative disorders, researchers are now directing their investigations toward the development of therapies. These therapies include molecules designed to protect mitochondria and neurons from the detrimental effects of aging, as well as mutant proteins. Our objective is to discuss and evaluate the recent discovery of three mitochondrial ribosomal proteins linked to Alzheimer's and Parkinson's diseases. These proteins represent an intermediate stage in the pathway connecting damaged genes to the two mitochondrial neurological pathologies. This discovery potentially could open new avenues for the production of medicinal substances with curative potential for the treatment of these diseases.
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Affiliation(s)
- Luigi Del Giudice
- Istituto di Bioscienze e BioRisorse-UOS Napoli-CNR c/o Dipartimento di Biologia, Sezione di Igiene, 80134 Napoli, Italy
| | - Paola Pontieri
- Istituto di Bioscienze e BioRisorse-UOS Napoli-CNR c/o Dipartimento di Biologia, Sezione di Igiene, 80134 Napoli, Italy
| | | | - Matteo Calcagnile
- Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Università del Salento, 73100 Lecce, Italy
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50
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McGrady NR, Boal AM, Risner ML, Taiel M, Sahel JA, Calkins DJ. Ocular stress enhances contralateral transfer of lenadogene nolparvovec gene therapy through astrocyte networks. Mol Ther 2023; 31:2005-2013. [PMID: 37016579 PMCID: PMC10362393 DOI: 10.1016/j.ymthe.2023.03.035] [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: 10/21/2022] [Revised: 02/10/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
Lenadogene nolparvovec (GS010) was developed to treat a point mutation in mitochondrial ND4 that causes Leber hereditary optic neuropathy. GS010 delivers human cDNA encoding wild-type ND4 packaged into an rAAV2/2 vector that transduces retinal ganglion cells, to induce allotopic expression of hybrid mitochondrial ND4. GS010 clinical trials improved best-corrected visual acuity (BCVA) up to 5 years after treatment. Interestingly, unilateral treatment improved BCVA bilaterally. Subsequent studies revealed GS010 DNA in visual tissues contralateral to the injected eye, suggesting migration. Here we tested whether unilateral intraocular pressure (IOP) elevation could influence the transfer of viral ND4 RNA in contralateral tissues after GS010 delivery to the IOP-elevated eye and probed a potential mechanism mediating translocation in mice. We found IOP elevation enhanced viral ND4 RNA transcripts in contralateral visual tissues, including retinas. Using conditional transgenic mice, we depleted astrocytic gap junction connexin 43 (Cx43), required for distant redistribution of metabolic resources between astrocytes during stress. After unilateral IOP elevation and GS010 injection, Cx43 knockdown eradicated ND4 RNA transcript detection in contralateral retinal tissues, while transcript was still detectable in optic nerves. Overall, our study indicates long-range migration of GS010 product to contralateral visual tissues is enhanced by Cx43-linked astrocyte networks.
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Affiliation(s)
- Nolan R McGrady
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Andrew M Boal
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Michael L Risner
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Jose A Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; Fondation Ophtalmologique A. de Rothschild, Paris, France; Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; CHNO des Quinze-Vingts, Institut Hospitalo-Universitaire FOReSIGHT, INSERM-DGOS CIC, Paris, France
| | - David J Calkins
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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