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Bernardino Gomes TM, Vincent AE, Menger KE, Stewart JB, Nicholls TJ. Mechanisms and pathologies of human mitochondrial DNA replication and deletion formation. Biochem J 2024; 481:683-715. [PMID: 38804971 DOI: 10.1042/bcj20230262] [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: 03/22/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024]
Abstract
Human mitochondria possess a multi-copy circular genome, mitochondrial DNA (mtDNA), that is essential for cellular energy metabolism. The number of copies of mtDNA per cell, and their integrity, are maintained by nuclear-encoded mtDNA replication and repair machineries. Aberrant mtDNA replication and mtDNA breakage are believed to cause deletions within mtDNA. The genomic location and breakpoint sequences of these deletions show similar patterns across various inherited and acquired diseases, and are also observed during normal ageing, suggesting a common mechanism of deletion formation. However, an ongoing debate over the mechanism by which mtDNA replicates has made it difficult to develop clear and testable models for how mtDNA rearrangements arise and propagate at a molecular and cellular level. These deletions may impair energy metabolism if present in a high proportion of the mtDNA copies within the cell, and can be seen in primary mitochondrial diseases, either in sporadic cases or caused by autosomal variants in nuclear-encoded mtDNA maintenance genes. These mitochondrial diseases have diverse genetic causes and multiple modes of inheritance, and show notoriously broad clinical heterogeneity with complex tissue specificities, which further makes establishing genotype-phenotype relationships challenging. In this review, we aim to cover our current understanding of how the human mitochondrial genome is replicated, the mechanisms by which mtDNA replication and repair can lead to mtDNA instability in the form of large-scale rearrangements, how rearranged mtDNAs subsequently accumulate within cells, and the pathological consequences when this occurs.
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Affiliation(s)
- Tiago M Bernardino Gomes
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- NHS England Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
| | - Amy E Vincent
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Katja E Menger
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - James B Stewart
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
| | - Thomas J Nicholls
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K
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Ramesh R, Amanmahanya C, Krishnamoorthy V, Krishnan V, Palani S, Narasimhan Ranganathan L. Oculomasticatory rhythmic movements, insomnia and stroke-like episodes in a patient with POLG mutation. BMJ Case Rep 2024; 17:e259426. [PMID: 38684350 PMCID: PMC11146406 DOI: 10.1136/bcr-2023-259426] [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] [Accepted: 04/19/2024] [Indexed: 05/02/2024] Open
Abstract
The POLG mutation, a leading cause of mitochondrial diseases, exhibits a wide-ranging age of onset and a complex clinical presentation. We encountered an atypical clinical profile in an elderly man with a POLG mutation, characterised by a stroke-like episode, chronic insomnia and transient oculomasticatory rhythmic movement. History revealed chronic constipation since his 50s and progressive bilateral ophthalmoplegia since his early 60s. Subsequently, he had experienced acute encephalopathy and later developed chronic insomnia. The present neurological examination showed bilateral complete ophthalmoplegia, ptosis, and rhythmic ocular and jaw movements. Imaging indicated findings suggestive of a stroke-like episode and eventual genetic analysis revealed a homozygous missense mutation in the POLG gene. This case expands the clinical spectrum of POLG mutations in individuals over 60 years, showcasing the rare combination of a stroke-like episode, chronic insomnia and oculomasticatory rhythmic movement.
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Affiliation(s)
- Rithvik Ramesh
- Neurology, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, Tamil Nadu, India
| | - Chitneni Amanmahanya
- Neurology, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, Tamil Nadu, India
| | - Vengadakrishnan Krishnamoorthy
- Internal Medicine, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, Tamil Nadu, India
| | - Vasanthan Krishnan
- Internal Medicine, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, Tamil Nadu, India
| | - Sathyamoorthy Palani
- Internal Medicine, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, Tamil Nadu, India
| | - Lakshmi Narasimhan Ranganathan
- Neurology, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, Tamil Nadu, India
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Gilea AI, Magistrati M, Notaroberto I, Tiso N, Dallabona C, Baruffini E. The Saccharomyces cerevisiae mitochondrial DNA polymerase and its contribution to the knowledge about human POLG-related disorders. IUBMB Life 2023; 75:983-1002. [PMID: 37470284 DOI: 10.1002/iub.2770] [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: 05/31/2023] [Accepted: 07/05/2023] [Indexed: 07/21/2023]
Abstract
Most eukaryotes possess a mitochondrial genome, called mtDNA. In animals and fungi, the replication of mtDNA is entrusted by the DNA polymerase γ, or Pol γ. The yeast Pol γ is composed only of a catalytic subunit encoded by MIP1. In humans, Pol γ is a heterotrimer composed of a catalytic subunit homolog to Mip1, encoded by POLG, and two accessory subunits. In the last 25 years, more than 300 pathological mutations in POLG have been identified as the cause of several mitochondrial diseases, called POLG-related disorders, which are characterized by multiple mtDNA deletions and/or depletion in affected tissues. In this review, at first, we summarize the biochemical properties of yeast Mip1, and how mutations, especially those introduced recently in the N-terminal and C-terminal regions of the enzyme, affect the in vitro activity of the enzyme and the in vivo phenotype connected to the mtDNA stability and to the mtDNA extended and point mutability. Then, we focus on the use of yeast harboring Mip1 mutations equivalent to the human ones to confirm their pathogenicity, identify the phenotypic defects caused by these mutations, and find both mechanisms and molecular compounds able to rescue the detrimental phenotype. A closing chapter will be dedicated to other polymerases found in yeast mitochondria, namely Pol ζ, Rev1 and Pol η, and to their genetic interactions with Mip1 necessary to maintain mtDNA stability and to avoid the accumulation of spontaneous or induced point mutations.
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Affiliation(s)
- Alexandru Ionut Gilea
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Martina Magistrati
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Ilenia Notaroberto
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Natascia Tiso
- Department of Biology, University of Padova, Padova, Italy
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
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Li X, Li C, Zhang W, Wang Y, Qian P, Huang H. Inflammation and aging: signaling pathways and intervention therapies. Signal Transduct Target Ther 2023; 8:239. [PMID: 37291105 PMCID: PMC10248351 DOI: 10.1038/s41392-023-01502-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 04/26/2023] [Accepted: 05/15/2023] [Indexed: 06/10/2023] Open
Abstract
Aging is characterized by systemic chronic inflammation, which is accompanied by cellular senescence, immunosenescence, organ dysfunction, and age-related diseases. Given the multidimensional complexity of aging, there is an urgent need for a systematic organization of inflammaging through dimensionality reduction. Factors secreted by senescent cells, known as the senescence-associated secretory phenotype (SASP), promote chronic inflammation and can induce senescence in normal cells. At the same time, chronic inflammation accelerates the senescence of immune cells, resulting in weakened immune function and an inability to clear senescent cells and inflammatory factors, which creates a vicious cycle of inflammation and senescence. Persistently elevated inflammation levels in organs such as the bone marrow, liver, and lungs cannot be eliminated in time, leading to organ damage and aging-related diseases. Therefore, inflammation has been recognized as an endogenous factor in aging, and the elimination of inflammation could be a potential strategy for anti-aging. Here we discuss inflammaging at the molecular, cellular, organ, and disease levels, and review current aging models, the implications of cutting-edge single cell technologies, as well as anti-aging strategies. Since preventing and alleviating aging-related diseases and improving the overall quality of life are the ultimate goals of aging research, our review highlights the critical features and potential mechanisms of inflammation and aging, along with the latest developments and future directions in aging research, providing a theoretical foundation for novel and practical anti-aging strategies.
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Affiliation(s)
- Xia Li
- Bone Marrow Transplantation Center, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, 310058, China
- Zhejiang Province Engineering Laboratory for Stem Cell and Immunity Therapy, Hangzhou, 310058, China
| | - Chentao Li
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Wanying Zhang
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Yanan Wang
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Pengxu Qian
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China.
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, 310058, China.
- Zhejiang Province Engineering Laboratory for Stem Cell and Immunity Therapy, Hangzhou, 310058, China.
- Center for Stem Cell and Regenerative Medicine and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - He Huang
- Bone Marrow Transplantation Center, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China.
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, 310058, China.
- Zhejiang Province Engineering Laboratory for Stem Cell and Immunity Therapy, Hangzhou, 310058, China.
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Borgione E, Lo Giudice M, Santa Paola S, Giuliano M, Lanza G, Cantone M, Ferri R, Scuderi C. The Y831C Mutation of the POLG Gene in Dementia. Biomedicines 2023; 11:biomedicines11041172. [PMID: 37189790 DOI: 10.3390/biomedicines11041172] [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: 01/27/2023] [Revised: 03/28/2023] [Accepted: 04/11/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND The POLG gene encodes the catalytic subunit of DNA polymerase γ, which is crucial for mitochondrial DNA (mtDNA) repair and replication. Gene mutation alters the stability of mtDNA and is associated with several clinical presentations, such as dysarthria and ophthalmoplegia (SANDO), progressive external ophthalmoplegia (PEO), spinocerebellar ataxia and epilepsy (SCAE), Alpers syndrome, and sensory ataxic neuropathy. Recent evidence has also indicated that POLG mutations may be involved in some neurodegenerative disorders, although systematic screening is currently lacking. METHODS To investigate the frequency of POLG gene mutations in neurodegenerative disorders, we screened a group of 33 patients affected by neurodegenerative diseases, including Parkinson's disease, some atypical parkinsonisms, and dementia of different types. RESULTS Mutational analysis revealed the presence of the heterozygous Y831C mutation in two patients, one with frontotemporal dementia and one with Lewy body dementia. The allele frequency of this mutation reported by the 1000 Genomes Project in the healthy population is 0.22%, while in our group of patients, it was 3.03%, thus showing a statistically significant difference between the two groups. CONCLUSIONS Our results may expand the genotype-phenotype spectrum associated with mutations in the POLG gene and strengthen the hypothesis of a pathogenic role of the Y831C mutation in neurodegeneration.
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Affiliation(s)
| | | | | | | | - Giuseppe Lanza
- Oasi Research Institute-IRCCS, 94018 Troina, Italy
- Department of Surgery and Medical-Surgical Specialties, University of Catania, 95123 Catania, Italy
| | - Mariagiovanna Cantone
- Neurology Unit, University Hospital Policlinico "G. Rodolico-San Marco", 95123 Catania, Italy
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Salahi M, Parsa S, Nourmohammadi D, Razmkhah Z, Salimi O, Rahmani M, Zivary S, Askarzadeh M, Tapak MA, Vaezi A, Sadeghsalehi H, Yaghoobpoor S, Mottahedi M, Garousi S, Deravi N. Immunologic aspects of migraine: A review of literature. Front Neurol 2022; 13:944791. [PMID: 36247795 PMCID: PMC9554313 DOI: 10.3389/fneur.2022.944791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 08/29/2022] [Indexed: 12/02/2022] Open
Abstract
Migraine headaches are highly prevalent, affecting 15% of the population. However, despite many studies to determine this disease's mechanism and efficient management, its pathophysiology has not been fully elucidated. There are suggested hypotheses about the possible mediating role of mast cells, immunoglobulin E, histamine, and cytokines in this disease. A higher incidence of this disease in allergic and asthma patients, reported by several studies, indicates the possible role of brain mast cells located around the brain vessels in this disease. The mast cells are more specifically within the dura and can affect the trigeminal nerve and cervical or sphenopalatine ganglion, triggering the secretion of substances that cause migraine. Neuropeptides such as calcitonin gene-related peptide (CGRP), neurokinin-A, neurotensin (NT), pituitary adenylate-cyclase-activating peptide (PACAP), and substance P (SP) trigger mast cells, and in response, they secrete pro-inflammatory and vasodilatory molecules such as interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) as a selective result of corticotropin-releasing hormone (CRH) secretion. This stress hormone contributes to migraine or intensifies it. Blocking these pathways using immunologic agents such as CGRP antibody, anti-CGRP receptor antibody, and interleukin-1 beta (IL-1β)/interleukin 1 receptor type 1 (IL-1R1) axis-related agents may be promising as potential prophylactic migraine treatments. This review is going to summarize the immunological aspects of migraine.
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Affiliation(s)
- Mehrnaz Salahi
- Student Research Committee, School of Pharmacy and Pharmaceutical Science, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sina Parsa
- Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Delaram Nourmohammadi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zahra Razmkhah
- Student Research Committee, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Omid Salimi
- Student Research Committee, Faculty of Medicine, Islamic Azad University of Najafabad, Isfahan, Iran
| | | | - Saeid Zivary
- Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran
| | - Monireh Askarzadeh
- Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Amin Tapak
- Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Ali Vaezi
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Sadeghsalehi
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shirin Yaghoobpoor
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehran Mottahedi
- Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Setareh Garousi
- Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Niloofar Deravi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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7
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Movement disorders and neuropathies: overlaps and mimics in clinical practice. J Neurol 2022; 269:4646-4662. [PMID: 35657406 DOI: 10.1007/s00415-022-11200-0] [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: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 10/18/2022]
Abstract
Movement disorders as well as peripheral neuropathies are extremely frequent in the general population; therefore, it is not uncommon to encounter patients with both these conditions. Often, the coexistence is coincidental, due to the high incidence of common causes of peripheral neuropathy, such as diabetes and other age-related disorders, as well as of Parkinson disease (PD), which has a typical late onset. Nonetheless, there is broad evidence that PD patients may commonly develop a sensory and/or autonomic polyneuropathy, triggered by intrinsic and/or extrinsic mechanisms. Similarly, some peripheral neuropathies may develop some movement disorders in the long run, such as tremor, and rarely dystonia and myoclonus, suggesting that central mechanisms may ensue in the pathogenesis of these diseases. Although rare, several acquired or hereditary causes may be responsible for the combination of movement and peripheral nerve disorders as a unique entity, some of which are potentially treatable, including paraneoplastic, autoimmune and nutritional aetiologies. Finally, genetic causes should be pursued in case of positive family history, young onset or multisystemic involvement, and examined for neuroacanthocytosis, spinocerebellar ataxias, mitochondrial disorders and less common causes of adult-onset cerebellar ataxias and spastic paraparesis. Deep phenotyping in terms of neurological and general examination, as well as laboratory tests, neuroimaging, neurophysiology, and next-generation genetic analysis, may guide the clinician toward the correct diagnosis and management.
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Hou Y, Zhao X, Xie Z, Yu M, Lv H, Zhang W, Yuan Y, Wang Z. Novel and recurrent nuclear gene variations in a cohort of Chinese progressive external ophthalmoplegia patients with multiple mtDNA deletions. Mol Genet Genomic Med 2022; 10:e1921. [PMID: 35289132 PMCID: PMC9034679 DOI: 10.1002/mgg3.1921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/30/2021] [Accepted: 02/25/2022] [Indexed: 11/07/2022] Open
Abstract
Objectives This study aimed to investigate the clinical and genetic spectrum in Chinese patients with multiple mtDNA deletions presenting with autosomal‐inherited mitochondrial progressive external ophthalmoplegia (PEO). Methods Long‐range polymerase chain reaction and massively parallel sequencing of the mitochondrial genome were performed to detect deletions in muscle mtDNA of 274 unrelated families. Then, targeted next generation sequencing was used to detect nuclear gene variations in patients with multiple mtDNA deletions. Results A total of 40 Chinese PEO patients (10 males and 30 females) from 20 families were found to have multiple mtDNA deletions in this study, and the median age at onset was 35 (1–70) years. PEO and positive family history were the two prominent features of these patients, and ataxia, neuropathy, and hypogonadism were also present as onset symptoms in some patients. Fifteen of 20 probands with multiple mtDNA deletions were identified to carry nuclear gene variants; eight (40.0%) probands had variants within POLG, two (10.0%) within TWNK, two (10.0%) within RRM2B, two (10.0%) within TK2, and one (5.0%) within POLG2. A total of 24 variants were found in these five nuclear genes, of which 19 were novel. The causal nuclear genetic factors in five pedigrees remain undetermined. Conclusions The POLG gene is the most common disease‐causing gene in this group of PEO patients with multiple mtDNA deletions. While inherited PEO is the most prominent symptoms in these patients, genotypic and phenotypic heterogeneity still exist, for example in onset age, initial symptoms, and accompanying manifestations.
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Affiliation(s)
- Yue Hou
- Department of Neurology, Peking University First Hospital, Beijing, China.,Department of Geriatrics, Peking University First Hospital, Beijing, China
| | - Xutong Zhao
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhiying Xie
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - He Lv
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing, China
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Kursun O, Yemisci M, van den Maagdenberg AMJM, Karatas H. Migraine and neuroinflammation: the inflammasome perspective. J Headache Pain 2021; 22:55. [PMID: 34112082 PMCID: PMC8192049 DOI: 10.1186/s10194-021-01271-1] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/01/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Neuroinflammation has an important role in the pathophysiology of migraine, which is a complex neuro-glio-vascular disorder. The main aim of this review is to highlight findings of cortical spreading depolarization (CSD)-induced neuroinflammatory signaling in brain parenchyma from the inflammasome perspective. In addition, we discuss the limited data of the contribution of inflammasomes to other aspects of migraine pathophysiology, foremost the activation of the trigeminovascular system and thereby the generation of migraine pain. MAIN BODY Inflammasomes are signaling multiprotein complexes and key components of the innate immune system. Their activation causes the production of inflammatory cytokines that can stimulate trigeminal neurons and are thus relevant to the generation of migraine pain. The contribution of inflammasome activation to pain signaling has attracted considerable attention in recent years. Nucleotide-binding domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) is the best characterized inflammasome and there is emerging evidence of its role in a variety of inflammatory pain conditions, including migraine. In this review, we discuss, from an inflammasome point of view, cortical spreading depolarization (CSD)-induced neuroinflammatory signaling in brain parenchyma, the connection with genetic factors that make the brain vulnerable to CSD, and the relation of the inflammasome with diseases that are co-morbid with migraine, including stroke, epilepsy, and the possible links with COVID-19 infection. CONCLUSION Neuroinflammatory pathways, specifically those involving inflammasome proteins, seem promising candidates as treatment targets, and perhaps even biomarkers, in migraine.
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Affiliation(s)
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Arn M J M van den Maagdenberg
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands.,Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Hulya Karatas
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
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Ptosis, ophthalmoplegia and corneal endothelial disease - ocular manifestations of mitochondrial disease. Am J Ophthalmol Case Rep 2021; 22:101073. [PMID: 33869891 PMCID: PMC8041719 DOI: 10.1016/j.ajoc.2021.101073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 02/03/2021] [Accepted: 03/07/2021] [Indexed: 11/20/2022] Open
Abstract
Purpose To describe two patients with bilateral ptosis, ophthalmoplegia, cataracts and corneal endothelial disease requiring corneal transplantation. Observations Histopathological analysis of muscle biopsy samples from both patients identified features consistent with a mitochondrial cytopathy. A single multigenic mitochondrial deoxyribonucleic acid (DNA) deletion was detected in the first patient. Pathogenic mutations in the POLG gene which codes for mitochondrial DNA polymerase, tasked with replicating the mitochondrial genome were identified in the second patient. Conclusion The collection of clinical features present in both cases described can be explained by a diagnosis of mitochondrial disease. Importance Corneal endothelial disease, in addition to ptosis, ophthalmoplegia, cataract, pigmentary retinopathy and optic atrophy should be recognised as a feature of mitochondrial disease.
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Key Words
- ATP, Adenosine triphosphate
- CHED, Congenital hereditary endothelial dystrophy
- COX, Cytochrome oxidase
- CPEO, Chronic progressive external ophthalmoplegia
- Corneal endothelial disease
- DNA, Deoxyribonucleic acid
- DSAEK, Descemet's stripping automated endothelial keratoplasty
- FECD, Fuchs endothelial corneal dystrophy
- LF, Levator palpebrae superioris function
- MELAS syndrome, Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke
- MRD1, Margin reflex 1 distance
- MT-ATP6, Mitochondrially encoded adenosine triphosphate synthase membrane subunit 6
- MT-TP, Mitochondrially encoded transfer ribonucleic acid proline
- Mitochondrial disease
- Ophthalmoplegia
- Ptosis
- RNA, Ribonucleic acid
- SDH, Succinic dehydrogenase
- TRNA, Transfer ribonucleic acid
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Clinical characteristics and diagnostic clues to Neurometabolic causes of dystonia. J Neurol Sci 2020; 419:117167. [DOI: 10.1016/j.jns.2020.117167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/22/2020] [Accepted: 09/29/2020] [Indexed: 12/30/2022]
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POLG1-Related Epilepsy: Review of Diagnostic and Therapeutic Findings. Brain Sci 2020; 10:brainsci10110768. [PMID: 33113942 PMCID: PMC7690674 DOI: 10.3390/brainsci10110768] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/14/2020] [Accepted: 10/20/2020] [Indexed: 11/30/2022] Open
Abstract
Background: The clinical spectrum associated with POLG1 gene mutations ranges from non-syndromic epilepsy or mild isolated neurological signs to neurodegenerative disorders. Our aim was to review diagnostic findings, therapeutic approaches and outcomes of reported cases of epilepsy related to POLG1 mutation. Methods: The articles for review were identified through a systematic research on PubMed and EMBASE databases from January 2003 to April 2020, searching for the terms “Epilepsy AND POLG OR polymerase gamma,” OR “POLG1”. Results: Forty-eight articles were selected for review, which included 195 patients. Two main peaks of age at epilepsy onset were found: at ages 1 and 13 years. The most frequent seizure type was myoclonic. The occurrence of Status Epilepticus was reported in 46.4% of cases. Epileptiform and slow abnormalities were most frequently seen over occipital regions. Brain Magnetic Resonance Imaging (MRI) revealed increased T2 signal intensities in thalamic regions. Genetic analysis revealed a prevalence of A467T, W748S and G848S (74.2% of patients) mutations. Survival at 5 years was estimated at very low levels (30.2% of patients). Conclusion: In this review, we included cases with both pediatric and adult epilepsy onset. The analysis of data regarding prognosis showed that survival is related to age at onset of epilepsy.
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Khan YA, Jungreis I, Wright JC, Mudge JM, Choudhary JS, Firth AE, Kellis M. Evidence for a novel overlapping coding sequence in POLG initiated at a CUG start codon. BMC Genet 2020; 21:25. [PMID: 32138667 PMCID: PMC7059407 DOI: 10.1186/s12863-020-0828-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 02/19/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND POLG, located on nuclear chromosome 15, encodes the DNA polymerase γ(Pol γ). Pol γ is responsible for the replication and repair of mitochondrial DNA (mtDNA). Pol γ is the only DNA polymerase found in mitochondria for most animal cells. Mutations in POLG are the most common single-gene cause of diseases of mitochondria and have been mapped over the coding region of the POLG ORF. RESULTS Using PhyloCSF to survey alternative reading frames, we found a conserved coding signature in an alternative frame in exons 2 and 3 of POLG, herein referred to as ORF-Y that arose de novo in placental mammals. Using the synplot2 program, synonymous site conservation was found among mammals in the region of the POLG ORF that is overlapped by ORF-Y. Ribosome profiling data revealed that ORF-Y is translated and that initiation likely occurs at a CUG codon. Inspection of an alignment of mammalian sequences containing ORF-Y revealed that the CUG codon has a strong initiation context and that a well-conserved predicted RNA stem-loop begins 14 nucleotides downstream. Such features are associated with enhanced initiation at near-cognate non-AUG codons. Reanalysis of the Kim et al. (2014) draft human proteome dataset yielded two unique peptides that map unambiguously to ORF-Y. An additional conserved uORF, herein referred to as ORF-Z, was also found in exon 2 of POLG. Lastly, we surveyed Clinvar variants that are synonymous with respect to the POLG ORF and found that most of these variants cause amino acid changes in ORF-Y or ORF-Z. CONCLUSIONS We provide evidence for a novel coding sequence, ORF-Y, that overlaps the POLG ORF. Ribosome profiling and mass spectrometry data show that ORF-Y is expressed. PhyloCSF and synplot2 analysis show that ORF-Y is subject to strong purifying selection. An abundance of disease-correlated mutations that map to exons 2 and 3 of POLG but also affect ORF-Y provides potential clinical significance to this finding.
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Affiliation(s)
- Yousuf A Khan
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
| | - Irwin Jungreis
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
| | - James C Wright
- Functional Proteomics, Division of Cancer Biology, Institute of Cancer Research, 123 Old Brompton Road, London, SW7 3RP, UK
| | - Jonathan M Mudge
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | | | - Andrew E Firth
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Manolis Kellis
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
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Abstract
The POLG gene encodes the mitochondrial DNA polymerase that is responsible for replication of the mitochondrial genome. Mutations in POLG can cause early childhood mitochondrial DNA (mtDNA) depletion syndromes or later-onset syndromes arising from mtDNA deletions. POLG mutations are the most common cause of inherited mitochondrial disorders, with as many as 2% of the population carrying these mutations. POLG-related disorders comprise a continuum of overlapping phenotypes with onset from infancy to late adulthood. The six leading disorders caused by POLG mutations are Alpers-Huttenlocher syndrome, which is one of the most severe phenotypes; childhood myocerebrohepatopathy spectrum, which presents within the first 3 years of life; myoclonic epilepsy myopathy sensory ataxia; ataxia neuropathy spectrum; autosomal recessive progressive external ophthalmoplegia; and autosomal dominant progressive external ophthalmoplegia. This Review describes the clinical features, pathophysiology, natural history and treatment of POLG-related disorders, focusing particularly on the neurological manifestations of these conditions.
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De Marchis ML, Guadagni F, Silvestris E, Lovero D, Della-Morte D, Ferroni P, Barbanti P, Palmirotta R. Genetic bases of the nutritional approach to migraine. Crit Rev Food Sci Nutr 2018. [PMID: 29517920 DOI: 10.1080/10408398.2018.1450215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Migraine is a common multifactorial and polygenic neurological disabling disorder characterized by a genetic background and associated to environmental, hormonal and food stimulations. A large series of evidence suggest a strong correlation between nutrition and migraine and indicates several commonly foods, food additives and beverages that may be involved in the mechanisms triggering the headache attack in migraine-susceptible persons. There are foods and drinks, or ingredients of the same, that can trigger the migraine crisis as well as some foods play a protective function depending on the specific genetic sensitivity of the subject. The recent biotechnological advances have enhanced the identification of some genetic factors involved in onset diseases and the identification of sequence variants of genes responsible for the individual sensitivity to migraine trigger-foods. Therefore many studies are aimed at the analysis of polymorphisms of genes coding for the enzymes involved in the metabolism of food factors in order to clarify the different ways in which people respond to foods based on their genetic constitution. This review discusses the latest knowledge and scientific evidence of the role of gene variants and nutrients, food additives and nutraceuticals interactions in migraine.
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Affiliation(s)
- Maria Laura De Marchis
- a Biobanca InterIstituzionale Multidisciplinare, IRCCS San Raffaele Pisana , Rome , Italy.,b Biotechnology Unit, Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri' , Rome , Italy
| | - Fiorella Guadagni
- a Biobanca InterIstituzionale Multidisciplinare, IRCCS San Raffaele Pisana , Rome , Italy.,c Department of Human Sciences and Quality of Life Promotion, San Raffaele Roma Open University , Rome , Italy
| | - Erica Silvestris
- d Department of Biomedical Sciences & Human Oncology, University of Bari 'Aldo Moro' , Bari , Italy
| | - Domenica Lovero
- d Department of Biomedical Sciences & Human Oncology, University of Bari 'Aldo Moro' , Bari , Italy
| | - David Della-Morte
- c Department of Human Sciences and Quality of Life Promotion, San Raffaele Roma Open University , Rome , Italy.,e Department of Systems Medicine University of Rome "Tor Vergata" , Rome , Italy
| | - Patrizia Ferroni
- a Biobanca InterIstituzionale Multidisciplinare, IRCCS San Raffaele Pisana , Rome , Italy.,c Department of Human Sciences and Quality of Life Promotion, San Raffaele Roma Open University , Rome , Italy
| | - Piero Barbanti
- f Headache and Pain Unit, Department of Neurological, Motor and Sensorial Sciences, IRCCS San Raffaele Pisana , Rome , Italy
| | - Raffaele Palmirotta
- d Department of Biomedical Sciences & Human Oncology, University of Bari 'Aldo Moro' , Bari , Italy
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17
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Vogel AP, Rommel N, Oettinger A, Horger M, Krumm P, Kraus EM, Schöls L, Synofzik M. Speech and swallowing abnormalities in adults with POLG associated ataxia (POLG-A). Mitochondrion 2017. [PMID: 28634151 DOI: 10.1016/j.mito.2017.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Mutations in the nuclear-encoded mitochondrial DNA polymerase gamma (POLG) can result in a wide spectrum of neurological deficits. A common presentation is progressive ataxia (POLG-A) which includes impaired speech and swallowing. The nature, severity and impact of these deficits in POLG-A is not known. A comprehensive quantitative and qualitative characterization of dysarthria and dysphagia in this recurrent ataxia disorder will assist in diagnostics, provide insights into the underlying pathology, and establish the foundation for future therapy trials. METHODS 14 consecutive patients with POLG (9 females, mean age=50.1y, SD=11.2) and 34 healthy controls were enrolled. Comprehensive assessments of motor speech and swallowing function, acoustic analysis of speech, videofluoroscopy and measures of quality of life were conducted. RESULTS The speech profile of individuals with POLG-A was characterized by poor control of pitch and strain-strangled voice quality, reduced rate of speech and longer variable silences between words, and articulatory breakdown including imprecise consonants and vowel distortions. Swallowing deficits included slower initiation of the swallow reflex, poor control of bolus and late epiglottic closure. Speech and swallowing related quality of life was worse than healthy controls. CONCLUSIONS The dysarthria and dysphagia profiles in POLG-A are largely symptomatic of impaired timing, indicating a mainly spinocerebellar deficit. Dysarthria and dysphagia contribute to a significant impairment in functional quality of life, and progress distinctly from other POLG-A dysfunctions like ataxia or cognitive impairment. Our assessments establish meaningful patient focused outcome measures that will be suitable for use in natural history studies and clinical trials.
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Affiliation(s)
- Adam P Vogel
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany & Center for Neurology, University Hospital Tübingen, Germany; Centre for Neuroscience of Speech, The University of Melbourne, Victoria, Australia; Redenlab, Melbourne, Australia.
| | - Natalie Rommel
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany & Center for Neurology, University Hospital Tübingen, Germany; Therapiezentrum, University Hospital Tübingen, Germany
| | - Andreas Oettinger
- Neurology and Rehabilitation, Kliniken Schmieder, Gailingen am Hochrhein, Germany
| | - Marius Horger
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Germany
| | - Patrick Krumm
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Germany
| | - Eva-Maria Kraus
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany & Center for Neurology, University Hospital Tübingen, Germany
| | - Ludger Schöls
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany & Center for Neurology, University Hospital Tübingen, Germany; Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Matthis Synofzik
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany & Center for Neurology, University Hospital Tübingen, Germany; Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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Da Pozzo P, Cardaioli E, Rubegni A, Gallus GN, Malandrini A, Rufa A, Battisti C, Carluccio MA, Rocchi R, Giannini F, Bianchi A, Mancuso M, Siciliano G, Dotti MT, Federico A. Novel POLG mutations and variable clinical phenotypes in 13 Italian patients. Neurol Sci 2017; 38:563-570. [DOI: 10.1007/s10072-016-2734-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/07/2016] [Indexed: 11/29/2022]
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Abstract
Mitochondrial disorders (MIDs) due to respiratory-chain defects or nonrespiratory chain defects are usually multisystem conditions [mitochondrial multiorgan disorder syndrome (MIMODS)] affecting the central nervous system (CNS), peripheral nervous system, eyes, ears, endocrine organs, heart, kidneys, bone marrow, lungs, arteries, and also the intestinal tract. Frequent gastrointestinal (GI) manifestations of MIDs include poor appetite, gastroesophageal sphincter dysfunction, constipation, dysphagia, vomiting, gastroparesis, GI pseudo-obstruction, diarrhea, or pancreatitis and hepatopathy. Rare GI manifestations of MIDs include dry mouth, paradontosis, tracheoesophageal fistula, stenosis of the duodeno-jejunal junction, atresia or imperforate anus, liver cysts, pancreas lipomatosis, pancreatic cysts, congenital stenosis or obstruction of the GI tract, recurrent bowel perforations with intra-abdominal abscesses, postprandial abdominal pain, diverticulosis, or pneumatosis coli. Diagnosing GI involvement in MIDs is not at variance from diagnosing GI disorders due to other causes. Treatment of mitochondrial GI disease includes noninvasive or invasive measures. Therapy is usually symptomatic. Only for myo-neuro-gastro-intestinal encephalopathy is a causal therapy with autologous stem-cell transplantation available. It is concluded that GI manifestations of MIDs are more widespread than so far anticipated and that they must be recognized as early as possible to initiate appropriate diagnostic work-up and avoid any mitochondrion-toxic treatment.
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Affiliation(s)
| | - Marlies Frank
- First Medical Department, Krankenanstalt Rudolfstiftung, Vienna, Austria
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20
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Anagnostou ME, Ng YS, Taylor RW, McFarland R. Epilepsy due to mutations in the mitochondrial polymerase gamma (POLG)
gene: A clinical and molecular genetic review. Epilepsia 2016; 57:1531-1545. [DOI: 10.1111/epi.13508] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Maria-Eleni Anagnostou
- Wellcome Trust Centre for Mitochondrial Research; Institute of Neuroscience; Newcastle University; Newcastle upon Tyne United Kingdom
| | - Yi Shiau Ng
- Wellcome Trust Centre for Mitochondrial Research; Institute of Neuroscience; Newcastle University; Newcastle upon Tyne United Kingdom
| | - Robert W. Taylor
- Wellcome Trust Centre for Mitochondrial Research; Institute of Neuroscience; Newcastle University; Newcastle upon Tyne United Kingdom
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research; Institute of Neuroscience; Newcastle University; Newcastle upon Tyne United Kingdom
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21
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Legati A, Reyes A, Nasca A, Invernizzi F, Lamantea E, Tiranti V, Garavaglia B, Lamperti C, Ardissone A, Moroni I, Robinson A, Ghezzi D, Zeviani M. New genes and pathomechanisms in mitochondrial disorders unraveled by NGS technologies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1326-1335. [PMID: 26968897 DOI: 10.1016/j.bbabio.2016.02.022] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 02/17/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Abstract
Next Generation Sequencing (NGS) technologies are revolutionizing the diagnostic screening for rare disease entities, including primary mitochondrial disorders, particularly those caused by nuclear gene defects. NGS approaches are able to identify the causative gene defects in small families and even single individuals, unsuitable for investigation by traditional linkage analysis. These technologies are contributing to fill the gap between mitochondrial disease cases defined on the basis of clinical, neuroimaging and biochemical readouts, which still outnumber by approximately 50% the cases for which a molecular-genetic diagnosis is attained. We have been using a combined, two-step strategy, based on targeted genes panel as a first NGS screening, followed by whole exome sequencing (WES) in still unsolved cases, to analyze a large cohort of subjects, that failed to show mutations in mtDNA and in ad hoc sets of specific nuclear genes, sequenced by the Sanger's method. Not only this approach has allowed us to reach molecular diagnosis in a significant fraction (20%) of these difficult cases, but it has also revealed unexpected and conceptually new findings. These include the possibility of marked variable penetrance of recessive mutations, the identification of large-scale DNA rearrangements, which explain spuriously heterozygous cases, and the association of mutations in known genes with unusual, previously unreported clinical phenotypes. Importantly, WES on selected cases has unraveled the presence of pathogenic mutations in genes encoding non-mitochondrial proteins (e.g. the transcription factor E4F1), an observation that further expands the intricate genetics of mitochondrial disease and suggests a new area of investigation in mitochondrial medicine. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Andrea Legati
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy
| | - Aurelio Reyes
- Mitochondrial Biology Unit, Medical Research Council, Cambridge CB2 0XY, UK
| | - Alessia Nasca
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy
| | - Federica Invernizzi
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy
| | - Eleonora Lamantea
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy
| | - Valeria Tiranti
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy
| | - Barbara Garavaglia
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy
| | - Costanza Lamperti
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy
| | - Anna Ardissone
- Unit of Child Neurology, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20133 Milan, Italy
| | - Isabella Moroni
- Unit of Child Neurology, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20133 Milan, Italy
| | - Alan Robinson
- Mitochondrial Biology Unit, Medical Research Council, Cambridge CB2 0XY, UK
| | - Daniele Ghezzi
- Unit of Molecular Neurogenetics, Fondazione IRCCS Istituto Neurologico 'Carlo Besta', 20126 Milan, Italy.
| | - Massimo Zeviani
- Mitochondrial Biology Unit, Medical Research Council, Cambridge CB2 0XY, UK.
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Kim DM, Kim H, Yeon JH, Lee JH, Park HO. Identification of a Mitochondrial DNA Polymerase Affecting Cardiotoxicity of Sunitinib Using a Genome-Wide Screening on S. pombe Deletion Library. Toxicol Sci 2015; 149:4-14. [PMID: 26385865 DOI: 10.1093/toxsci/kfv210] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Drug toxicity is a key issue for drug R&D, a fundamental challenge of which is to screen for the targets genome-wide. The anticancer tyrosine kinase inhibitor sunitinib is known to induce cardiotoxicity. Here, to understand the molecular insights of cardiotoxicity by sunitinib at the genome level, we used a genome-wide drug target screening technology (GPScreen) that measures drug-induced haploinsufficiency (DIH) in the fission yeast Schizosaccharomyces pombe genome-wide deletion library and found a mitochondrial DNA polymerase (POG1). In the results, sunitinib induced more severe cytotoxicity and mitochondrial damage in POG1-deleted heterozygous mutants compared to wild type (WT) of S. pombe. Furthermore, knockdown of the human ortholog POLG of S. pombe POG1 in human cells significantly increased the cytotoxicity of sunitinib. Notably, sunitinib dramatically decreased the levels of POLG mRNAs and proteins, of which downregulation was already known to induce mitochondrial damage of cardiomyocytes, causing cardiotoxicity. These results indicate that POLG might play a crucial role in mitochondrial damage as a gene of which expressional pathway is targeted by sunitinib for cardiotoxicity, and that genome-wide drug target screening with GPScreen can be applied to drug toxicity target discovery to understand the molecular insights regarding drug toxicity.
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Affiliation(s)
- Dong-Myung Kim
- GPScreen Team, Bioneer Corporation, Daejeon 306-220, Republic of Korea
| | - Hanna Kim
- GPScreen Team, Bioneer Corporation, Daejeon 306-220, Republic of Korea
| | - Ji-Hyun Yeon
- GPScreen Team, Bioneer Corporation, Daejeon 306-220, Republic of Korea
| | - Ju-Hee Lee
- GPScreen Team, Bioneer Corporation, Daejeon 306-220, Republic of Korea
| | - Han-Oh Park
- GPScreen Team, Bioneer Corporation, Daejeon 306-220, Republic of Korea
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23
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Linkowska K, Jawień A, Marszałek A, Malyarchuk BA, Tońska K, Bartnik E, Skonieczna K, Grzybowski T. Mitochondrial DNA Polymerase γ Mutations and Their Implications in mtDNA Alterations in Colorectal Cancer. Ann Hum Genet 2015; 79:320-328. [PMID: 25850945 DOI: 10.1111/ahg.12111] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 01/26/2015] [Indexed: 01/16/2023]
Abstract
Mitochondrial DNA was found to be highly mutated in colorectal cancer cells. One of the key molecules involved in the maintenance of the mitochondrial genome is the nuclear-encoded polymerase gamma. The aim of our study was to determine if there is a link between polymorphisms within the polymerase gamma gene (POLG) and somatic mutations within the mitochondrial genome in cancer cells. We investigated POLG sequence variability in 50 colorectal cancer patients whose complete mitochondrial genome sequences were determined. Relative mtDNA copy number was also determined. We identified 251 sequence variants in the POLG gene. Most of them were germline-specific (∼92%). Twenty-one somatic changes in POLG were found in 10 colorectal cancer patients. We have found no association between the occurrence of mtDNA somatic mutations and the somatically occurring variants in POLG. MtDNA content was reduced in patients carrying somatic variants in POLG or germline nucleotide variants located in the region encoding the POLG polymerase domain, but the difference did not reach statistical significance. Our findings suggest that somatic mtDNA mutations occurring in colorectal cancer are not a consequence of somatic mutations in POLG. Nevertheless, POLG nucleotide variants may lead to a decrease in mtDNA content, and consequently result in mitochondrial dysfunction.
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Affiliation(s)
- Katarzyna Linkowska
- Department of Molecular and Forensic Genetics, Institute of Forensic Medicine, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Arkadiusz Jawień
- Chair of Vascular Surgery and Angiology, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Andrzej Marszałek
- Chair & Department of Clinical Pathomorphology, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Boris A Malyarchuk
- Institute of Biological Problems of the North, Far-East Branch of the Russian Academy of Sciences, Magadan, Russia
| | - Katarzyna Tońska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Ewa Bartnik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland.,Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Katarzyna Skonieczna
- Department of Molecular and Forensic Genetics, Institute of Forensic Medicine, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Tomasz Grzybowski
- Department of Molecular and Forensic Genetics, Institute of Forensic Medicine, Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
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Zabalza R, Nurminen A, Kaguni LS, Garesse R, Gallardo ME, Bornstein B. Co-occurrence of four nucleotide changes associated with an adult mitochondrial ataxia phenotype. BMC Res Notes 2014; 7:883. [PMID: 25488682 PMCID: PMC4295309 DOI: 10.1186/1756-0500-7-883] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 11/18/2014] [Indexed: 11/19/2022] Open
Abstract
Background Mitochondrial DNA maintenance disorders are an important cause of hereditary ataxia syndrome, and the majority are associated with mutations in the gene encoding the catalytic subunit of the mitochondrial DNA polymerase (DNA polymerase gamma), POLG. Mutations resulting in the amino acid substitutions A467T and W748S are the most common genetic causes of inherited cerebellar ataxia in Europe. Methods We report here a POLG mutational screening in a family with a mitochondrial ataxia phenotype. To evaluate the likely pathogenicity of each of the identified changes, a 3D structural analysis of the PolG protein was carried out, using the Alpers mutation clustering tool reported previously. Results Three novel nucleotide changes and the p.Q1236H polymorphism have been identified in the affected members of the pedigree. Computational analysis suggests that the p.K601E mutation is likely the major contributing factor to the pathogenic phenotype. Conclusions Computational analysis of the PolG protein suggests that the p.K601E mutation is likely the most significant contributing factor to a pathogenic phenotype. However, the co-occurrence of multiple POLG alleles may be necessary in the development an adult-onset mitochondrial ataxia phenotype.
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Affiliation(s)
| | | | | | | | - M Esther Gallardo
- Departamento de Bioquímica, Facultad de Medicina, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red (CIBERER), Madrid, Spain.
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25
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Abstract
Migraine is the most frequent type of headache in children. In the 1980s, scientists first hypothesized a connection between migraine and mitochondrial (mt) disorders. More recent studies have suggested that at least some subtypes of migraine may be related to a mt defect. Different types of evidence support a relationship between mitochondria (mt) and migraine: (1) Biochemical evidence: Abnormal mt function translates into high intracellular penetration of Ca(2+), excessive production of free radicals, and deficient oxidative phosphorylation, which ultimately causes energy failure in neurons and astrocytes, thus triggering migraine mechanisms, including spreading depression. The mt markers of these events are low activity of superoxide dismutase, activation of cytochrome-c oxidase and nitric oxide, high levels of lactate and pyruvate, and low ratios of phosphocreatine-inorganic phosphate and N-acetylaspartate-choline. (2) Morphologic evidence: mt abnormalities have been shown in migraine sufferers, the most characteristic ones being direct observation in muscle biopsy of ragged red and cytochrome-c oxidase-negative fibers, accumulation of subsarcolemmal mt, and demonstration of giant mt with paracrystalline inclusions. (3) Genetic evidence: Recent studies have identified specific mutations responsible for migraine susceptibility. However, the investigation of the mtDNA mutations found in classic mt disorders (mt encephalomyopathy with lactic acidosis and stroke-like episodes, myoclonus epilepsy with ragged red fibers, Kearns-Sayre syndrome, and Leber hereditary optic neuropathy) has not demonstrated any association. Recently, 2 common mtDNA polymorphisms (16519C→T and 3010G→A) have been associated with pediatric cyclic vomiting syndrome and migraine. Also, POLG mutations (eg, p.T851 A, p.N468D, p.Y831C, p.G517V, and p.P163S) can cause disease through impaired replication of mtDNA, including migraine. Further studies to investigate the relationship between mtDNA and migraine will require very large sample sizes to obtain statistically significant results. (4) Therapeutic evidence: Several agents that have a positive effect on mt metabolism have shown to be effective in the treatment of migraines. The agents include riboflavin (B2), coenzyme Q10, magnesium, niacin, carnitine, topiramate, and lipoic acid. Further study is warranted to learn how mt interact with other factors to cause migraines. This will facilitate the development of new and more specific treatments that will reduce the frequency or severity or both of this disease.
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Affiliation(s)
- William R Yorns
- Section of Neurology, St. Christopher's Hospital for Children, Philadelphia, PA; Departments of Pediatrics and Neurology, Drexel University College of Medicine, Philadelphia, PA
| | - H Huntley Hardison
- Section of Neurology, St. Christopher's Hospital for Children, Philadelphia, PA; Departments of Pediatrics and Neurology, Drexel University College of Medicine, Philadelphia, PA.
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Swett RJ, Elias A, Miller JA, Dyson GE, Andrés Cisneros G. Hypothesis driven single nucleotide polymorphism search (HyDn-SNP-S). DNA Repair (Amst) 2013; 12:733-40. [PMID: 23830898 DOI: 10.1016/j.dnarep.2013.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/27/2013] [Accepted: 06/11/2013] [Indexed: 12/28/2022]
Abstract
The advent of complete-genome genotyping across phenotype cohorts has provided a rich source of information for bioinformaticians. However the search for SNPs from this data is generally performed on a study-by-study case without any specific hypothesis of the location for SNPs that are predictive for the phenotype. We have designed a method whereby very large SNP lists (several gigabytes in size), combining several genotyping studies at once, can be sorted and traced back to their ultimate consequence in protein structure. Given a working hypothesis, researchers are able to easily search whole genome genotyping data for SNPs that link genetic locations to phenotypes. This allows a targeted search for correlations between phenotypes and potentially relevant systems, rather than utilizing statistical methods only. HyDn-SNP-S returns results that are less data dense, allowing more thorough analysis, including haplotype analysis. We have applied our method to correlate DNA polymerases to cancer phenotypes using four of the available cancer databases in dbGaP. Logistic regression and derived haplotype analysis indicates that ~80SNPs, previously overlooked, are statistically significant. Derived haplotypes from this work link POLL to breast cancer and POLG to prostate cancer with an increase in incidence of 3.01- and 9.6-fold, respectively. Molecular dynamics simulations on wild-type and one of the SNP mutants from the haplotype of POLL provide insights at the atomic level on the functional impact of this cancer related SNP. Furthermore, HyDn-SNP-S has been designed to allow application to any system. The program is available upon request from the authors.
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Affiliation(s)
- Rebecca J Swett
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA
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