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Mascia E, Nale V, Ferrè L, Sorosina M, Clarelli F, Chiodi A, Santoro S, Giordano A, Misra K, Cannizzaro M, Moiola L, Martinelli V, Milanesi L, Filippi M, Mosca E, Esposito F. Genetic Contribution to Medium-Term Disease Activity in Multiple Sclerosis. Mol Neurobiol 2024:10.1007/s12035-024-04264-8. [PMID: 38850349 DOI: 10.1007/s12035-024-04264-8] [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: 03/12/2024] [Accepted: 05/25/2024] [Indexed: 06/10/2024]
Abstract
Multiple sclerosis (MS) is a complex disorder characterized by high heterogeneity in terms of phenotypic expression, prognosis and treatment response. In the present study, we aimed to explore the genetic contribution to MS disease activity at different levels: genes, pathways and tissue-specific networks. Two cohorts of relapsing-remitting MS patients who started a first-line treatment (n = 1294) were enrolled to evaluate the genetic association with disease activity after 4 years of follow-up. The analyses were performed at whole-genome SNP and gene level, followed by the construction of gene-gene interaction networks specific for brain and lymphocytes. The resulting gene modules were evaluated to highlight key players from a topological and functional perspective. We identified 23 variants and 223 genes with suggestive association to 4-years disease activity, highlighting genes like PON2 involved in oxidative stress and in mitochondria functions and other genes, like ILRUN, involved in the modulation of the immune system. Network analyses led to the identification of a brain module composed of 228 genes and a lymphocytes module composed of 287 genes. The network analysis allowed us to prioritize genes relevant for their topological properties; among them, there are MPHOSPH9 (connector hub in both brain and lymphocyte module) and OPA1 (in brain module), two genes already implicated in MS. Modules showed the enrichment of both shared and tissue-specific pathways, mainly implicated in inflammation. In conclusion, our results suggest that the processes underlying disease activity act on shared mechanisms across brain and lymphocyte tissues.
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Affiliation(s)
- Elisabetta Mascia
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Valentina Nale
- Institute of Biomedical Technologies, National Research Council, Segrate, Italy
| | - Laura Ferrè
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology and Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Melissa Sorosina
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Ferdinando Clarelli
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alice Chiodi
- Institute of Biomedical Technologies, National Research Council, Segrate, Italy
| | - Silvia Santoro
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Antonino Giordano
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology and Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Kaalindi Misra
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Miryam Cannizzaro
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology and Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Lucia Moiola
- Neurology and Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Vittorio Martinelli
- Neurology and Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Luciano Milanesi
- Institute of Biomedical Technologies, National Research Council, Segrate, Italy
| | - Massimo Filippi
- Neurology and Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
- Neurophysiology Service, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Ettore Mosca
- Institute of Biomedical Technologies, National Research Council, Segrate, Italy
| | - Federica Esposito
- Laboratory of Human Genetics of Neurological Disorders, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.
- Neurology and Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy.
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2
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Takai Y, Yamagami A, Ishikawa H. [Leber's hereditary optic neuropathy]. Rinsho Shinkeigaku 2024; 64:326-332. [PMID: 38644210 DOI: 10.5692/clinicalneurol.cn-001924] [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: 04/23/2024]
Abstract
Leber's hereditary optic atrophy (LHON) is a genetic optic neuropathy that is more prevalent in young males but can occur from childhood to old age. The primary cause is mitochondrial genetic mutations, which are associated with dysfunction of mitochondrial electron transport chain complex I. It manifests as acute to subacute visual impairment, often starting unilaterally but progressing to involve both eyes within weeks to months. Visual loss is severe, with many patients having corrected visual acuity below 0.1. The differential diagnosis of optic neuritis is essential, and assessments such as pupillary light reflex, fluorescein fundus angiography, and magnetic resonance imaging can be useful for differentiation. LHON should be considered as one of the differential diagnoses for optic neuritis, and collaboration between neurologists and ophthalmologists is crucial for accurate diagnosis and appropriate treatment.
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Affiliation(s)
| | | | - Hitoshi Ishikawa
- Department of Orthoptics and Visual Science, School of Allied Health Sciences, Kitazato University
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Shi Y, Zhang K, Dong G, Pan H, Chen B, Wang A, Niu S, Wang X, Zhang Z. Dystonia, spastic tetraplegia, and ataxia due to a novel mutation in the dynamin domain of OPA1. Ann Clin Transl Neurol 2024; 11:800-805. [PMID: 38148580 DOI: 10.1002/acn3.51981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 11/09/2023] [Accepted: 12/07/2023] [Indexed: 12/28/2023] Open
Abstract
Movement disorders manifest in various hereditary neurodegenerative diseases. We reported a young man who presented with progressive upper limb dystonia, spastic tetraplegia, and ataxia. Whole-exome sequencing (WES) revealed a novel variant, c.2357A > G, in the dynamin domain of OPA1. No mtDNA deletion was detected in muscle by long-range PCR. Atrophy and decreased glucose metabolism of the basal ganglia were discovered. Decreased mtDNA copy number, fragmented mitochondria, slightly impaired oxidative phosphorylation, and increased autophagy were detected in mutant fibroblasts. Evident oxidative phosphorylation impairment and mtDNA deletions were not involved in the pathogenicity of this mutation unlike mutations in the GTPase domain of OPA1.
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Affiliation(s)
- YuZhi Shi
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kang Zhang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - GeHong Dong
- Department of Pathology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Hua Pan
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- China National Clinical Research Center for Neurological Disease, Beijing, China
| | - Bin Chen
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - An Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - SongTao Niu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - XinGao Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - ZaiQiang Zhang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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Atkinson KC, Osunde M, Tiwari-Woodruff SK. The complexities of investigating mitochondria dynamics in multiple sclerosis and mouse models of MS. Front Neurosci 2023; 17:1144896. [PMID: 37559701 PMCID: PMC10409489 DOI: 10.3389/fnins.2023.1144896] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 06/23/2023] [Indexed: 08/11/2023] Open
Abstract
Multiple sclerosis (MS) is a demyelinating, degenerating disorder of the central nervous system (CNS) that is accompanied by mitochondria energy production failure. A loss of myelin paired with a deficit in energy production can contribute to further neurodegeneration and disability in patients in MS. Mitochondria are essential organelles that produce adenosine triphosphate (ATP) via oxidative phosphorylation in all cells in the CNS, including neurons, oligodendrocytes, astrocytes, and immune cells. In the context of demyelinating diseases, mitochondria have been shown to alter their morphology and undergo an initial increase in metabolic demand. This is followed by mitochondrial respiratory chain deficiency and abnormalities in mitochondrial transport that contribute to progressive neurodegeneration and irreversible disability. The current methodologies to study mitochondria are limiting and are capable of providing only a partial snapshot of the true mitochondria activity at a particular timepoint during disease. Mitochondrial functional studies are mostly performed in cell culture or whole brain tissue, which prevents understanding of mitochondrial pathology in distinct cell types in vivo. A true understanding of cell-specific mitochondrial pathophysiology of MS in mouse models is required. Cell-specific mitochondria morphology, mitochondria motility, and ATP production studies in animal models of MS will help us understand the role of mitochondria in the normal and diseased CNS. In this review, we present currently used methods to investigate mitochondria function in MS mouse models and discuss the current advantages and caveats with using each technique. In addition, we present recently developed mitochondria transgenic mouse lines expressing Cre under the control of CNS specific promoters to relate mitochondria to disease in vivo.
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Affiliation(s)
| | | | - Seema K. Tiwari-Woodruff
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
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5
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Abstract
Mitochondrial optic neuropathies have a leading role in the field of mitochondrial medicine ever since 1988, when the first mutation in mitochondrial DNA was associated with Leber's hereditary optic neuropathy (LHON). Autosomal dominant optic atrophy (DOA) was subsequently associated in 2000 with mutations in the nuclear DNA affecting the OPA1 gene. LHON and DOA are both characterized by selective neurodegeneration of retinal ganglion cells (RGCs) triggered by mitochondrial dysfunction. This is centered on respiratory complex I impairment in LHON and defective mitochondrial dynamics in OPA1-related DOA, leading to distinct clinical phenotypes. LHON is a subacute, rapid, severe loss of central vision involving both eyes within weeks or months, with age of onset between 15 and 35 years old. DOA is a more slowly progressive optic neuropathy, usually apparent in early childhood. LHON is characterized by marked incomplete penetrance and a clear male predilection. The introduction of next-generation sequencing has greatly expanded the genetic causes for other rare forms of mitochondrial optic neuropathies, including recessive and X-linked, further emphasizing the exquisite sensitivity of RGCs to compromised mitochondrial function. All forms of mitochondrial optic neuropathies, including LHON and DOA, can manifest either as pure optic atrophy or as a more severe multisystemic syndrome. Mitochondrial optic neuropathies are currently at the forefront of a number of therapeutic programs, including gene therapy, with idebenone being the only approved drug for a mitochondrial disorder.
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Affiliation(s)
- Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy.
| | - Chiara La Morgia
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Patrick Yu-Wai-Man
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom; Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom
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6
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Hametner S, Silvaieh S, Thurnher M, Dal-Bianco A, Cetin H, Ponleitner M, Zebenholzer K, Pemp B, Trattnig S, Rössler K, Berger T, Lassmann H, Hainfellner JA, Bsteh G. A case of primary optic pathway demyelination caused by oncocytic oligodendrogliopathy of unknown origin. Acta Neuropathol Commun 2022; 10:160. [DOI: 10.1186/s40478-022-01462-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/13/2022] [Indexed: 11/11/2022] Open
Abstract
AbstractWe report the case of a 22-year-old woman presenting with an acute onset of dizziness, gait dysbalance and blurred vision. Magnetic resonance imaging included 3 Tesla and 7 Tesla imaging and revealed a T2-hyperintense, T1-hypointense, non-contrast-enhancing lesion strictly confined to the white matter affecting the right optic radiation. An extensive ophthalmologic examination yielded mild quadrantanopia but no signs of optic neuropathy. The lesion was biopsied. The neuropathological evaluation revealed a demyelinating lesion with marked tissue vacuolization and granular myelin disintegration accompanied by mild T cell infiltration and a notable absence of myelin uptake by macrophages. Oligodendrocytes were strikingly enlarged, displaying oncocytic characteristics and showed cytoplasmic accumulation of mitochondria, which had mildly abnormal morphology on electron microscopy. The diagnosis of multiple sclerosis was excluded. Harding's disease, a variant of Leber's hereditary optic neuropathy, was then suspected. However, neither PCR for relevant mutations nor whole exome sequencing yielded known pathogenetic mutations in the patient's genome. We present a pattern of demyelinating tissue injury of unknown etiology with an oncocytic change of oligodendrocytes and a lack of adequate phagocytic response by macrophages, which to the best of our knowledge, has not been described before.
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Harvey JP, Yu-Wai-Man P, Cheetham ME. Characterisation of a novel OPA1 splice variant resulting in cryptic splice site activation and mitochondrial dysfunction. Eur J Hum Genet 2022; 30:848-855. [PMID: 35534703 PMCID: PMC9259687 DOI: 10.1038/s41431-022-01102-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/01/2022] [Accepted: 04/12/2022] [Indexed: 12/13/2022] Open
Abstract
Autosomal dominant optic atrophy (DOA) is an inherited optic neuropathy that results in progressive, bilateral visual acuity loss and field defects. OPA1 is the causative gene in around 60% of cases of DOA. The majority of patients have a pure ocular phenotype, but 20% have extra-ocular features (DOA +). We report on a patient with DOA + manifesting as bilateral optic atrophy, spastic paraparesis, urinary incontinence and white matter changes in the central nervous system associated with a novel heterozygous splice variant NM_015560.2(OPA1):c.2356-1 G > T. Further characterisation, which was performed using fibroblasts obtained from a skin biopsy, demonstrated that this variant altered mRNA splicing of the OPA1 transcript, specifically a 21 base pair deletion at the start of exon 24, NM_015560.2(OPA1):p.Cys786_Lys792del. The majority of variant transcripts were shown to escape nonsense-mediated decay and modelling of the predicted protein structure suggests that the in-frame 7 amino acid deletion may affect OPA1 oligomerisation. Fibroblasts carrying the c.2356-1 G > T variant demonstrated impaired mitochondrial bioenergetics, membrane potential, increased cell death, and disrupted and fragmented mitochondrial networks in comparison to WT cells. This study suggests that the c.2356-1 G > T OPA1 splice site variant leads to a cryptic splice site activation and may manifest in a dominant-negative manner, which could account for the patient's severe syndromic phenotype.
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Affiliation(s)
- Joshua Paul Harvey
- UCL Institute of Ophthalmology, London, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.
| | - Patrick Yu-Wai-Man
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
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Zeviani M, Carelli V. Mitochondrial Retinopathies. Int J Mol Sci 2021; 23:210. [PMID: 35008635 PMCID: PMC8745158 DOI: 10.3390/ijms23010210] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/14/2021] [Accepted: 12/18/2021] [Indexed: 12/13/2022] Open
Abstract
The retina is an exquisite target for defects of oxidative phosphorylation (OXPHOS) associated with mitochondrial impairment. Retinal involvement occurs in two ways, retinal dystrophy (retinitis pigmentosa) and subacute or chronic optic atrophy, which are the most common clinical entities. Both can present as isolated or virtually exclusive conditions, or as part of more complex, frequently multisystem syndromes. In most cases, mutations of mtDNA have been found in association with mitochondrial retinopathy. The main genetic abnormalities of mtDNA include mutations associated with neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) sometimes with earlier onset and increased severity (maternally inherited Leigh syndrome, MILS), single large-scale deletions determining Kearns-Sayre syndrome (KSS, of which retinal dystrophy is a cardinal symptom), and mutations, particularly in mtDNA-encoded ND genes, associated with Leber hereditary optic neuropathy (LHON). However, mutations in nuclear genes can also cause mitochondrial retinopathy, including autosomal recessive phenocopies of LHON, and slowly progressive optic atrophy caused by dominant or, more rarely, recessive, mutations in the fusion/mitochondrial shaping protein OPA1, encoded by a nuclear gene on chromosome 3q29.
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Affiliation(s)
- Massimo Zeviani
- Department of Neurosciences, The Clinical School, University of Padova, 35128 Padova, Italy
- Veneto Institute of Molecular Medicine, Via Orus 2, 35128 Padova, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40139 Bologna, Italy
- Programma di Neurogenetica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura 6, 40139 Bologna, Italy
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9
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Del Dotto V, Carelli V. Dominant Optic Atrophy (DOA): Modeling the Kaleidoscopic Roles of OPA1 in Mitochondrial Homeostasis. Front Neurol 2021; 12:681326. [PMID: 34177786 PMCID: PMC8220150 DOI: 10.3389/fneur.2021.681326] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/22/2021] [Indexed: 02/05/2023] Open
Abstract
In the year 2000, the discovery of OPA1 mutations as causative for dominant optic atrophy (DOA) was pivotal to rapidly expand the field of mitochondrial dynamics and describe the complex machinery governing this pathway, with a multitude of other genes and encoded proteins involved in neurodegenerative disorders of the optic nerve. OPA1 turned out to be a much more complex protein than initially envisaged, connecting multiple pathways beyond its strict role in mitochondrial fusion, such as sensing of OXPHOS needs and mitochondrial DNA maintenance. As a consequence, an increasing need to investigate OPA1 functions at multiple levels has imposed the development of multiple tools and models that are here reviewed. Translational mitochondrial medicine, with the ultimate objective of translating basic science necessary to understand pathogenic mechanisms into therapeutic strategies, requires disease modeling at multiple levels: from the simplest, like in yeast, to cell models, including the increasing use of reprogrammed stem cells (iPSCs) from patients, to animal models. In the present review, we thoroughly examine and provide the state of the art of all these approaches.
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Affiliation(s)
- Valentina Del Dotto
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
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Cretin E, Lopes P, Vimont E, Tatsuta T, Langer T, Gazi A, Sachse M, Yu‐Wai‐Man P, Reynier P, Wai T. High-throughput screening identifies suppressors of mitochondrial fragmentation in OPA1 fibroblasts. EMBO Mol Med 2021; 13:e13579. [PMID: 34014035 PMCID: PMC8185549 DOI: 10.15252/emmm.202013579] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 12/22/2022] Open
Abstract
Mutations in OPA1 cause autosomal dominant optic atrophy (DOA) as well as DOA+, a phenotype characterized by more severe neurological deficits. OPA1 deficiency causes mitochondrial fragmentation and also disrupts cristae, respiration, mitochondrial DNA (mtDNA) maintenance, and cell viability. It has not yet been established whether phenotypic severity can be modulated by genetic modifiers of OPA1. We screened the entire known mitochondrial proteome (1,531 genes) to identify genes that control mitochondrial morphology using a first-in-kind imaging pipeline. We identified 145 known and novel candidate genes whose depletion promoted elongation or fragmentation of the mitochondrial network in control fibroblasts and 91 in DOA+ patient fibroblasts that prevented mitochondrial fragmentation, including phosphatidyl glycerophosphate synthase (PGS1). PGS1 depletion reduces CL content in mitochondria and rebalances mitochondrial dynamics in OPA1-deficient fibroblasts by inhibiting mitochondrial fission, which improves defective respiration, but does not rescue mtDNA depletion, cristae dysmorphology, or apoptotic sensitivity. Our data reveal that the multifaceted roles of OPA1 in mitochondria can be functionally uncoupled by modulating mitochondrial lipid metabolism, providing novel insights into the cellular relevance of mitochondrial fragmentation.
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Affiliation(s)
- Emma Cretin
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
- Université de ParisParisFrance
| | - Priscilla Lopes
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
| | - Elodie Vimont
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
| | | | - Thomas Langer
- Max‐Planck‐Institute for Biology of AgeingCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Anastasia Gazi
- UTechS Ultrastructural Bio ImagingInstitut PasteurParisFrance
| | - Martin Sachse
- UTechS Ultrastructural Bio ImagingInstitut PasteurParisFrance
| | - Patrick Yu‐Wai‐Man
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology UnitDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Cambridge Eye UnitAddenbrooke's HospitalCambridge University HospitalsCambridgeUK
- Moorfields Eye HospitalLondonUK
- UCL Institute of OphthalmologyUniversity College LondonLondonUK
| | - Pascal Reynier
- Laboratoire de Biochimie et biologie moléculaireCentre Hospitalier UniversitaireAngersFrance
- Unité Mixte de Recherche MITOVASCCNRS 6015INSERM U1083Université d'AngersAngersFrance
| | - Timothy Wai
- Mitochondrial Biology GroupInstitut PasteurCNRS UMR 3691ParisFrance
- Université de ParisParisFrance
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11
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Mitochondria, Oxidative Stress, cAMP Signalling and Apoptosis: A Crossroads in Lymphocytes of Multiple Sclerosis, a Possible Role of Nutraceutics. Antioxidants (Basel) 2020; 10:antiox10010021. [PMID: 33379309 PMCID: PMC7823468 DOI: 10.3390/antiox10010021] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 12/11/2022] Open
Abstract
Multiple sclerosis (MS) is a complex inflammatory and neurodegenerative chronic disease that involves the immune and central nervous systems (CNS). The pathogenesis involves the loss of blood–brain barrier integrity, resulting in the invasion of lymphocytes into the CNS with consequent tissue damage. The MS etiology is probably a combination of immunological, genetic, and environmental factors. It has been proposed that T lymphocytes have a main role in the onset and propagation of MS, leading to the inflammation of white matter and myelin sheath destruction. Cyclic AMP (cAMP), mitochondrial dysfunction, and oxidative stress exert a role in the alteration of T lymphocytes homeostasis and are involved in the apoptosis resistance of immune cells with the consequent development of autoimmune diseases. The defective apoptosis of autoreactive lymphocytes in patients with MS, allows these cells to perpetuate, within the CNS, a continuous cycle of inflammation. In this review, we discuss the involvement in MS of cAMP pathway, mitochondria, reactive oxygen species (ROS), apoptosis, and their interaction in the alteration of T lymphocytes homeostasis. In addition, we discuss a series of nutraceutical compounds that could influence these aspects.
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12
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De Rasmo D, Ferretta A, Russo S, Ruggieri M, Lasorella P, Paolicelli D, Trojano M, Signorile A. PBMC of Multiple Sclerosis Patients Show Deregulation of OPA1 Processing Associated with Increased ROS and PHB2 Protein Levels. Biomedicines 2020; 8:biomedicines8040085. [PMID: 32290388 PMCID: PMC7235786 DOI: 10.3390/biomedicines8040085] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/08/2020] [Accepted: 04/10/2020] [Indexed: 02/06/2023] Open
Abstract
Multiple sclerosis (MS) is an autoimmune disease in which activated lymphocytes affect the central nervous system. Increase of reactive oxygen species (ROS), impairment of mitochondria-mediated apoptosis and mitochondrial alterations have been reported in peripheral lymphocytes of MS patients. Mitochondria-mediated apoptosis is regulated by several mechanisms and proteins. Among others, optic atrophy 1 (OPA1) protein plays a key role in the regulating mitochondrial dynamics, cristae architecture and release of pro-apoptotic factors. Very interesting, mutations in OPA1 gene, have been associated with multiple sclerosis-like disorder. We have analyzed OPA1 and some factors involved in its regulation. Fifteen patients with MS and fifteen healthy control subjects (HC) were enrolled into the study and peripheral blood mononuclear cells (PBMCs) were isolated. H2O2 level was measured spectrofluorimetrically, OPA1, PHB2, SIRT3, and OMA1 were analyzed by western blotting. Statistical analysis was performed using Student's t-test. The results showed that PBMC of MS patients were characterized by a deregulation of OPA1 processing associated with increased H2O2 production, inactivation of OMA1 and increase of PHB2 protein level. The presented data suggest that the alteration of PHB2, OMA1, and OPA1 processing could be involved in resistance towards apoptosis. These molecular parameters could also be useful to assess disease activity.
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Affiliation(s)
- Domenico De Rasmo
- CNR-Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, 70126 Bari, Italy
- Correspondence: (D.D.R.); (A.S.); Tel.: +39-080-547-8529 (D.D.R. & A.S.)
| | - Anna Ferretta
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy; (A.F.); (S.R.); (M.R.); (P.L.); (D.P.); (M.T.)
| | - Silvia Russo
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy; (A.F.); (S.R.); (M.R.); (P.L.); (D.P.); (M.T.)
| | - Maddalena Ruggieri
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy; (A.F.); (S.R.); (M.R.); (P.L.); (D.P.); (M.T.)
| | - Piergiorgio Lasorella
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy; (A.F.); (S.R.); (M.R.); (P.L.); (D.P.); (M.T.)
| | - Damiano Paolicelli
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy; (A.F.); (S.R.); (M.R.); (P.L.); (D.P.); (M.T.)
| | - Maria Trojano
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy; (A.F.); (S.R.); (M.R.); (P.L.); (D.P.); (M.T.)
| | - Anna Signorile
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy; (A.F.); (S.R.); (M.R.); (P.L.); (D.P.); (M.T.)
- Correspondence: (D.D.R.); (A.S.); Tel.: +39-080-547-8529 (D.D.R. & A.S.)
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13
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An evaluation of genetic causes and environmental risks for bilateral optic atrophy. PLoS One 2019; 14:e0225656. [PMID: 31765440 PMCID: PMC6876833 DOI: 10.1371/journal.pone.0225656] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 11/08/2019] [Indexed: 12/15/2022] Open
Abstract
Purpose To assess the clinical utility of next-generation sequencing (NGS) for the diagnosis of patients with optic atrophy (OA). Design Retrospective cohort study. Methods 97 patients were referred to the McMaster University Medical Center (Hamilton, Ontario) for evaluation of bilateral OA. All patients were sent for NGS including a 22 nuclear gene panel and/or complete mitochondrial DNA (mtDNA) sequencing. Positive genetic test results and abnormal vibration sensation were compared in patients +/- environmental exposures or a family history. Results 19/94 (20.2%) had a positive nuclear variant, of which 15/19 (78.9%) were in the OPA1 gene. No positive mtDNA variants were identified. The detection of a positive genetic variant was significantly different in patients who reported excessive ethanol use, but not in patients who smoke (0/19 (0%) vs. 19/78 (24.4%), P = 0.0164 and 4/22 (18.2%) vs. 15/74 (20.3%), P = 0.829, respectively). Patients with a positive family history were more likely to have a positive genetic variant compared to patients with a negative family history (P = 0.0112). There were significantly more excessive drinkers with an abnormal vibration sensation (P = 0.026), and with a similar trend in smokers (P = 0.074). Conclusions All positive genetic variants were identified in nuclear genes. We identified a potential independent pathophysiological link between a history of excessive ethanol consumption and bilateral OA. Further investigations should evaluate and identify potential environmental risk factors for OA.
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14
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Bargiela D, Chinnery PF. Mitochondria in neuroinflammation – Multiple sclerosis (MS), leber hereditary optic neuropathy (LHON) and LHON-MS. Neurosci Lett 2019; 710:132932. [DOI: 10.1016/j.neulet.2017.06.051] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 06/27/2017] [Indexed: 01/12/2023]
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15
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Marelli C, Salsano E, Politi LS, Labauge P. Spinal cord involvement in adult-onset metabolic and genetic diseases. J Neurol Neurosurg Psychiatry 2019; 90:211-218. [PMID: 30150321 DOI: 10.1136/jnnp-2018-318666] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 07/23/2018] [Accepted: 07/23/2018] [Indexed: 12/11/2022]
Abstract
In adulthood, spinal cord MRI abnormalities such as T2-weighted hyperintensities and atrophy are commonly associated with a large variety of causes (inflammation, infections, neoplasms, vascular and spondylotic diseases). Occasionally, they can be due to rare metabolic or genetic diseases, in which the spinal cord involvement can be a prominent or even predominant feature, or a secondary one. This review focuses on these rare diseases and associated spinal cord abnormalities, which can provide important but over-ridden clues for the diagnosis. The review was based on a PubMed search (search terms: 'spinal cord' AND 'leukoencephalopathy' OR 'leukodystrophy'; 'spinal cord' AND 'vitamin'), further integrated according to the authors' personal experience and knowledge. The genetic and metabolic diseases of adulthood causing spinal cord signal alterations were identified and classified into four groups: (1) leukodystrophies; (2) deficiency-related metabolic diseases; (3) genetic and acquired toxic/metabolic causes; and (4) mitochondrial diseases. A number of genetic and metabolic diseases of adulthood causing spinal cord atrophy without signal alterations were also identified. Finally, a classification based on spinal MRI findings is presented, as well as indications about the diagnostic work-up and differential diagnosis. Some of these diseases are potentially treatable (especially if promptly recognised), while others are inherited as autosomal dominant trait. Therefore, a timely diagnosis is needed for a timely therapy and genetic counselling. In addition, spinal cord may be the main site of pathology in many of these diseases, suggesting a tempting role for spinal cord abnormalities as surrogate MRI biomarkers.
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Affiliation(s)
- Cecilia Marelli
- Department of Neurology, Gui de Chauliac University Hospital, Montpellier, France .,Expert Center for Neurogenetic Diseases and Adult Mitochondrial and Metabolic Diseases, Gui de Chauliac University Hospital, Montpellier, France.,EA7402 Institut Universitaire de Recherche Clinique and Laboratoire de Genetique Moleculaire, Gui de Chauliac University Hospital, Montpellier, France.,MMDN, Université de Montpellier, EPHE, Inserm UMR-S1198, Montpellier, France
| | - Ettore Salsano
- Unit of Neurodegenerative and Neurometabolic Rare Diseases, RCCS Foundation 'Carlo Besta' Neurological Institute, Milan, Italy
| | - Letterio S Politi
- Advanced MRI Centre, University of Massachusetts Medical School, Worcester, USA.,Neuroimaging Research, Boston Children's Hospital, Boston, MA, USA
| | - Pierre Labauge
- Department of Neurology, Gui de Chauliac University Hospital, Montpellier, France.,Reference Centre for Adult Leukodystrophies, Gui de Chauliac University Hospital, Montpellier, France
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16
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Patel KR, Karaa A, Mateen FJ. Relapsing remitting multiple sclerosis in progressive external ophthalmoplegia: A report of two cases. Mult Scler 2018; 25:879-882. [DOI: 10.1177/1352458518800794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Evidence from genetic and pathologic studies suggests that mitochondrial dysfunction occurs in multiple sclerosis (MS). Furthermore, cases of MS have been reported in patients with mitochondrial disease. The phenotypic range of mitochondrial illness associating with MS is not yet well defined. In this report, we highlight two cases of patients with confirmed genetic mutations responsible for progressive external ophthalmoplegia who independently meet McDonald criteria for MS. Better characterization of the range of mitochondrial disease associated with MS may improve our understanding of MS disease pathophysiology.
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Affiliation(s)
- Kevin R Patel
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Amel Karaa
- Department of Genetics, Massachusetts General Hospital, Boston, MA, USA
| | - Farrah J Mateen
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA/ Harvard Medical School, Boston, MA, USA
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17
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Ham M, Han J, Osann K, Smith M, Kimonis V. Meta-analysis of genotype-phenotype analysis of OPA1 mutations in autosomal dominant optic atrophy. Mitochondrion 2018; 46:262-269. [PMID: 30165240 DOI: 10.1016/j.mito.2018.07.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 05/20/2018] [Accepted: 07/31/2018] [Indexed: 01/21/2023]
Abstract
Autosomal Dominant Optic Atrophy (ADOA) is a neuro-ophthalmic disease characterized by progressive bilateral vision loss, pallor of the optic disc, central vision loss, and impairment of color vision. Additionally, a small percentage of patients experience hearing loss and ataxia, while recent studies suggest disruption of cardiac and neuromuscular functions. In order to obtain a better understanding of the genotype-phenotype correlation of the various mutations in the optic atrophy 1 (OPA1) gene, we obtained both clinical and genetic information of ADOA patients from published reports. We conducted a systematic review of published OPA1 literature and identified 408 individuals with confirmed OPA1 mutations, 120 of whom reported extra-ocular (ADOA 'plus') manifestations through their descriptions of visual and multi-systemic symptoms. Our results show that there is a significant variation in frequency of the specific exons involved between the ADOA classic and ADOA 'plus' patients. Classic ADOA groups were more likely to have mutations in exon 8 and 9, while ADOA 'plus' groups were more likely to have mutations in exons 14, 15 and 17. Additional comparisons revealed significant differences between mutation types/domains and specific ADOA 'plus' manifestations. We also found that individuals with maternally inherited OPA1 mutations were significantly more likely to develop 'plus' manifestations than those with paternally inherited mutations. Overall, this study provides novel information regarding genotype-phenotype correlations of ADOA which warrants additional recommendations added to the current clinical management of ADOA patients.
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Affiliation(s)
- Michelle Ham
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Julia Han
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Kathryn Osann
- Department of Medicine, Division of Hematology-Oncology, University of California, Irvine, CA, USA
| | - Moyra Smith
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA
| | - Virginia Kimonis
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, CA, USA.
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18
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Del Dotto V, Fogazza M, Musiani F, Maresca A, Aleo SJ, Caporali L, La Morgia C, Nolli C, Lodi T, Goffrini P, Chan D, Carelli V, Rugolo M, Baruffini E, Zanna C. Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3496-3514. [PMID: 30293569 DOI: 10.1016/j.bbadis.2018.08.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 07/24/2018] [Accepted: 08/01/2018] [Indexed: 11/19/2022]
Abstract
OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA "plus". Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two "ad hoc" generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1-/- MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA "plus" phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions.
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Affiliation(s)
- Valentina Del Dotto
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy
| | - Mario Fogazza
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Alessandra Maresca
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Serena J Aleo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Leonardo Caporali
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Chiara La Morgia
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Cecilia Nolli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - David Chan
- Division of Biology and Biological Engineering, California Institute of Technology (CALTECH), Pasadena, CA 91125, USA
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, 40139 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, 40139 Bologna, Italy
| | - Michela Rugolo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy.
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19
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Ng YS, Lax NZ, Maddison P, Alston CL, Blakely EL, Hepplewhite PD, Riordan G, Meldau S, Chinnery PF, Pierre G, Chronopoulou E, Du A, Hughes I, Morris AA, Kamakari S, Chrousos G, Rodenburg RJ, Saris CGJ, Feeney C, Hardy SA, Sakakibara T, Sudo A, Okazaki Y, Murayama K, Mundy H, Hanna MG, Ohtake A, Schaefer AM, Champion MP, Turnbull DM, Taylor RW, Pitceathly RDS, McFarland R, Gorman GS. MT-ND5 Mutation Exhibits Highly Variable Neurological Manifestations at Low Mutant Load. EBioMedicine 2018; 30:86-93. [PMID: 29506874 PMCID: PMC5952215 DOI: 10.1016/j.ebiom.2018.02.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/03/2018] [Accepted: 02/12/2018] [Indexed: 01/06/2023] Open
Abstract
Mutations in the m.13094T>C MT-ND5 gene have been previously described in three cases of Leigh Syndrome (LS). In this retrospective, international cohort study we identified 20 clinically affected individuals (13 families) and four asymptomatic carriers. Ten patients were deceased at the time of analysis (median age of death was 10years (range: 5·4months-37years, IQR=17·9years). Nine patients manifested with LS, one with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), and one with Leber hereditary optic neuropathy. The remaining nine patients presented with either overlapping syndromes or isolated neurological symptoms. Mitochondrial respiratory chain activity analysis was normal in five out of ten muscle biopsies. We confirmed maternal inheritance in six families, and demonstrated marked variability in tissue segregation, and phenotypic expression at relatively low blood mutant loads. Neuropathological studies of two patients manifesting with LS/MELAS showed prominent capillary proliferation, microvacuolation and severe neuronal cell loss in the brainstem and cerebellum, with conspicuous absence of basal ganglia involvement. These findings suggest that whole mtDNA genome sequencing should be considered in patients with suspected mitochondrial disease presenting with complex neurological manifestations, which would identify over 300 known pathogenic variants including the m.13094T>C.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Nichola Z Lax
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Paul Maddison
- Department of Neurology, Queen's Medical Centre, Nottingham, UK
| | - Charlotte L Alston
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Emma L Blakely
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Philippa D Hepplewhite
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Gillian Riordan
- Paediatric Neurology Department, Red Cross War Memorial Children's Hospital, Cape Town, South Africa
| | - Surita Meldau
- Division of Chemical Pathology, Faculty of Health Sciences, University of Cape Town, South Africa; National Health Laboratory Service, Cape Town, South Africa
| | - Patrick F Chinnery
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK; Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Cambridge, UK
| | - Germaine Pierre
- Department of Inherited Metabolic Disease, Division of Women's and Children's Services, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Efstathia Chronopoulou
- Department of Inherited Metabolic Disease, Division of Women's and Children's Services, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Ailian Du
- Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Imelda Hughes
- Royal Manchester Children's Hospital, Central Manchester University Hospitals NHS Foundation Trust, UK
| | - Andrew A Morris
- Institute of Human Development, University of Manchester, Manchester M13 9WL, UK; Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Smaragda Kamakari
- Ophthalmic Genetics Unit, OMMA, Institute of Ophthalmology, Athens, Greece
| | - Georgia Chrousos
- Pediatric Ophthalmology Department, MITERA Children's Hospital, Athens, Greece
| | - Richard J Rodenburg
- Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christiaan G J Saris
- Department of Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Catherine Feeney
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Steven A Hardy
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Takafumi Sakakibara
- Department of Pediatrics, Nara Medical University Hospital, Nara 634-8522, Japan
| | - Akira Sudo
- Department of Pediatrics, Sapporo City General Hospital, Sapporo 060-8604, Japan
| | - Yasushi Okazaki
- Diagnostics and Therapeutics of Intractable Diseases, Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Tokyo 113-8421, Japan
| | - Kei Murayama
- Department of Metabolism, Chiba Children's Hospital, Chiba 266-0007, Japan
| | - Helen Mundy
- Evelina London Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Akira Ohtake
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, Saitama 350-0495, Japan
| | - Andrew M Schaefer
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Mike P Champion
- Evelina London Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Robert D S Pitceathly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.
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20
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Carelli V, La Morgia C, Ross-Cisneros FN, Sadun AA. Optic neuropathies: the tip of the neurodegeneration iceberg. Hum Mol Genet 2018; 26:R139-R150. [PMID: 28977448 PMCID: PMC5886475 DOI: 10.1093/hmg/ddx273] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 07/10/2017] [Indexed: 01/06/2023] Open
Abstract
The optic nerve and the cells that give origin to its 1.2 million axons, the retinal ganglion cells (RGCs), are particularly vulnerable to neurodegeneration related to mitochondrial dysfunction. Optic neuropathies may range from non-syndromic genetic entities, to rare syndromic multisystem diseases with optic atrophy such as mitochondrial encephalomyopathies, to age-related neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease where optic nerve involvement has, until recently, been a relatively overlooked feature. New tools are available to thoroughly investigate optic nerve function, allowing unparalleled access to this part of the central nervous system. Understanding the molecular pathophysiology of RGC neurodegeneration and optic atrophy, is key to broadly understanding the pathogenesis of neurodegenerative disorders, for monitoring their progression in describing the natural history, and ultimately as outcome measures to evaluate therapies. In this review, the different layers, from molecular to anatomical, that may contribute to RGC neurodegeneration and optic atrophy are tackled in an integrated way, considering all relevant players. These include RGC dendrites, cell bodies and axons, the unmyelinated retinal nerve fiber layer and the myelinated post-laminar axons, as well as olygodendrocytes and astrocytes, looked for unconventional functions. Dysfunctional mitochondrial dynamics, transport, homeostatic control of mitobiogenesis and mitophagic removal, as well as specific propensity to apoptosis may target differently cell types and anatomical settings. Ultimately, we can envisage new investigative approaches and therapeutic options that will speed the early diagnosis of neurodegenerative diseases and their cure.
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Affiliation(s)
- Valerio Carelli
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | | | - Alfredo A Sadun
- Doheny Eye Institute, Los Angeles, CA 90033, USA.,Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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21
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OPA1: How much do we know to approach therapy? Pharmacol Res 2018; 131:199-210. [PMID: 29454676 DOI: 10.1016/j.phrs.2018.02.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/12/2018] [Accepted: 02/12/2018] [Indexed: 01/01/2023]
Abstract
OPA1 is a GTPase that controls several functions, such as mitochondrial dynamics and energetics, mtDNA maintenance and cristae integrity. In the last years, there have been described other cellular pathways and mechanisms involving OPA1 directly or through its interaction. All this new information, by implementing our knowledge on OPA1 is instrumental to elucidating the pathogenic mechanisms of OPA1 mutations. Indeed, these are associated with dominant optic atrophy (DOA), one of the most common inherited optic neuropathies, and with an increasing number of heterogeneous neurodegenerative disorders. In this review, we overview all recent findings on OPA1 protein functions, on its dysfunction and related clinical phenotypes, focusing on the current therapeutic options and future perspectives to treat DOA and the other associated neurological disorders due to OPA1 mutations.
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22
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Finsterer J, Zarrouk-Mahjoub S. Leigh-like syndrome due to OPA1 mutations. Eur J Paediatr Neurol 2017; 21:921-922. [PMID: 28711503 DOI: 10.1016/j.ejpn.2017.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/29/2017] [Indexed: 10/19/2022]
Affiliation(s)
| | - Sinda Zarrouk-Mahjoub
- University of Tunis El Manar and Genomics Platform, Pasteur Institute of Tunis, Tunisia
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23
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Abstract
The report in 1988 that Leber Hereditary Optic Neuropathy (LHON) was the product of mitochondrial DNA (mtDNA) mutations provided the first demonstration of the clinical relevance of inherited mtDNA variation. From LHON studies, the medical importance was demonstrated for the mtDNA showing its coding for the most important energy genes, its maternal inheritance, its high mutation rate, its presence in hundreds to thousands of copies per cell, its quantitatively segregation of biallelic genotypes during both mitosis and meiosis, its preferential effect on the most energetic tissues including the eye and brain, its wide range of functional polymorphisms that predispose to common diseases, and its accumulation of mutations within somatic tissues providing the aging clock. These features of mtDNA genetics, in combination with the genetics of the 1-2000 nuclear DNA (nDNA) coded mitochondrial genes, is not only explaining the genetics of LHON but also providing a model for understanding the complexity of many common diseases. With the maturation of LHON biology and genetics, novel animal models for complex disease have been developed and new therapeutic targets and strategies envisioned, both pharmacological and genetic. Multiple somatic gene therapy approaches are being developed for LHON which are applicable to other mtDNA diseases. Moreover, the unique cytoplasmic genetics of the mtDNA has permitted the first successful human germline gene therapy via spindle nDNA transfer from mtDNA mutant oocytes to enucleated normal mtDNA oocytes. Such LHON lessons are actively being applied to common ophthalmological diseases like glaucoma and neurological diseases like Parkinsonism.
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24
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A neurodegenerative perspective on mitochondrial optic neuropathies. Acta Neuropathol 2016; 132:789-806. [PMID: 27696015 PMCID: PMC5106504 DOI: 10.1007/s00401-016-1625-2] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 09/24/2016] [Accepted: 09/25/2016] [Indexed: 12/15/2022]
Abstract
Mitochondrial optic neuropathies constitute an important cause of chronic visual morbidity and registrable blindness in both the paediatric and adult population. It is a genetically heterogeneous group of disorders caused by both mitochondrial DNA (mtDNA) mutations and a growing list of nuclear genetic defects that invariably affect a critical component of the mitochondrial machinery. The two classical paradigms are Leber hereditary optic neuropathy (LHON), which is a primary mtDNA disorder, and autosomal dominant optic atrophy (DOA) secondary to pathogenic mutations within the nuclear gene OPA1 that encodes for a mitochondrial inner membrane protein. The defining neuropathological feature is the preferential loss of retinal ganglion cells (RGCs) within the inner retina but, rather strikingly, the smaller calibre RGCs that constitute the papillomacular bundle are particularly vulnerable, whereas melanopsin-containing RGCs are relatively spared. Although the majority of patients with LHON and DOA will present with isolated optic nerve involvement, some individuals will also develop additional neurological complications pointing towards a greater vulnerability of the central nervous system (CNS) in susceptible mutation carriers. These so-called “plus” phenotypes are mechanistically important as they put the loss of RGCs within the broader perspective of neuronal loss and mitochondrial dysfunction, highlighting common pathways that could be modulated to halt progressive neurodegeneration in other related CNS disorders. The management of patients with mitochondrial optic neuropathies still remains largely supportive, but the development of effective disease-modifying treatments is now within tantalising reach helped by major advances in drug discovery and delivery, and targeted genetic manipulation.
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