1
|
Ladero M, Reche-Sainz JA, Gallardo ME. Hereditary Optic Neuropathies: A Systematic Review on the Interplay between Biomaterials and Induced Pluripotent Stem Cells. Bioengineering (Basel) 2024; 11:52. [PMID: 38247929 PMCID: PMC10813088 DOI: 10.3390/bioengineering11010052] [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: 11/27/2023] [Revised: 12/29/2023] [Accepted: 12/30/2023] [Indexed: 01/23/2024] Open
Abstract
Hereditary optic neuropathies (HONs) such as dominant optic atrophy (DOA) and Leber Hereditary Optic Neuropathy (LHON) are mitochondrial diseases characterized by a degenerative loss of retinal ganglion cells (RGCs) and are a cause of blindness worldwide. To date, there are only limited disease-modifying treatments for these disorders. The discovery of induced pluripotent stem cell (iPSC) technology has opened several promising opportunities in the field of HON research and the search for therapeutic approaches. This systematic review is focused on the two most frequent HONs (LHON and DOA) and on the recent studies related to the application of human iPSC technology in combination with biomaterials technology for their potential use in the development of RGC replacement therapies with the final aim of the improvement or even the restoration of the vision of HON patients. To this purpose, the combination of natural and synthetic biomaterials modified with peptides, neurotrophic factors, and other low- to medium-molecular weight compounds, mimicking the ocular extracellular matrices, with human iPSC or iPSC-derived cell retinal progenitors holds enormous potential to be exploited in the near future for the generation of transplantable RGC populations.
Collapse
Affiliation(s)
- Miguel Ladero
- FQPIMA Group, Materials and Chemical Engineering Department, Chemical Sciences School, Complutense University of Madrid, 28040 Madrid, Spain
| | - Jose Alberto Reche-Sainz
- Ophthalmology Unit, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
- Translational Research with iPS Cells Group, Research Institute of Hospital 12 de Octubre, imas12, 28041 Madrid, Spain
| | - M. Esther Gallardo
- Translational Research with iPS Cells Group, Research Institute of Hospital 12 de Octubre, imas12, 28041 Madrid, Spain
| |
Collapse
|
2
|
Del Negro I, Pauletto G, Verriello L, Spadea L, Salati C, Ius T, Zeppieri M. Uncovering the Genetics and Physiology behind Optic Neuritis. Genes (Basel) 2023; 14:2192. [PMID: 38137014 PMCID: PMC10742654 DOI: 10.3390/genes14122192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
Optic neuritis (ON) is an inflammatory condition affecting the optic nerve, leading to vision impairment and potential vision loss. This manuscript aims to provide a comprehensive review of the current understanding of ON, including its definition, epidemiology, physiology, genetics, molecular pathways, therapy, ongoing clinical studies, and future perspectives. ON is characterized by inflammation of the optic nerve, often resulting from an autoimmune response. Epidemiological studies have shown a higher incidence in females and an association with certain genetic factors. The physiology of ON involves an immune-mediated attack on the myelin sheath surrounding the optic nerve, leading to demyelination and subsequent impairment of nerve signal transmission. This inflammatory process involves various molecular pathways, including the activation of immune cells and the release of pro-inflammatory cytokines. Genetic factors play a significant role in the susceptibility to ON. Several genes involved in immune regulation and myelin maintenance have been implicated in the disease pathogenesis. Understanding the genetic basis can provide insights into disease mechanisms and potential therapeutic targets. Therapy for ON focuses on reducing inflammation and promoting nerve regeneration. Future perspectives involve personalized medicine approaches based on genetic profiling, regenerative therapies to repair damaged myelin, and the development of neuroprotective strategies. Advancements in understanding molecular pathways, genetics, and diagnostic tools offer new opportunities for targeted therapies and improved patient outcomes in the future.
Collapse
Affiliation(s)
- Ilaria Del Negro
- Clinical Neurology Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, 33100 Udine, Italy;
| | - Giada Pauletto
- Neurology Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, 33100 Udine, Italy; (G.P.)
| | - Lorenzo Verriello
- Neurology Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, 33100 Udine, Italy; (G.P.)
| | - Leopoldo Spadea
- Eye Clinic, Policlinico Umberto I, “Sapienza” University of Rome, 00142 Rome, Italy
| | - Carlo Salati
- Department of Ophthalmology, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, 33100 Udine, Italy
| | - Tamara Ius
- Neurosurgery Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital of Udine, 33100 Udine, Italy
| | - Marco Zeppieri
- Department of Ophthalmology, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, 33100 Udine, Italy
| |
Collapse
|
3
|
Pohl KA, Zhang X, Pham AH, Chan JW, Sadun AA, Yang XJ. Establishing induced pluripotent stem cell lines from two dominant optic atrophy patients with distinct OPA1 mutations and clinical pathologies. Front Genet 2023; 14:1251216. [PMID: 37745862 PMCID: PMC10513078 DOI: 10.3389/fgene.2023.1251216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 08/17/2023] [Indexed: 09/26/2023] Open
Abstract
Dominant optic atrophy (DOA) is an inherited disease that leads to the loss of retinal ganglion cells (RGCs), the projection neurons that relay visual information from the retina to the brain through the optic nerve. The majority of DOA cases can be attributed to mutations in optic atrophy 1 (OPA1), a nuclear gene encoding a mitochondrial-targeted protein that plays important roles in maintaining mitochondrial structure, dynamics, and bioenergetics. Although OPA1 is ubiquitously expressed in all human tissues, RGCs appear to be the primary cell type affected by OPA1 mutations. DOA has not been extensively studied in human RGCs due to the general unavailability of retinal tissues. However, recent advances in stem cell biology have made it possible to produce human RGCs from pluripotent stem cells (PSCs). To aid in establishing DOA disease models based on human PSC-derived RGCs, we have generated iPSC lines from two DOA patients who carry distinct OPA1 mutations and present very different disease symptoms. Studies using these OPA1 mutant RGCs can be correlated with clinical features in the patients to provide insights into DOA disease mechanisms.
Collapse
Affiliation(s)
- Katherine A. Pohl
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Xiangmei Zhang
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Anh H. Pham
- Department of Ophthalmology, Doheny Eye Institute, University of California, Los Angeles, Pasadena, CA, United States
| | - Jane W. Chan
- Department of Ophthalmology, Doheny Eye Institute, University of California, Los Angeles, Pasadena, CA, United States
| | - Alfredo A. Sadun
- Department of Ophthalmology, Doheny Eye Institute, University of California, Los Angeles, Pasadena, CA, United States
| | - Xian-Jie Yang
- Department of Ophthalmology, Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
4
|
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.
Collapse
Affiliation(s)
| | | | - Seema K. Tiwari-Woodruff
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| |
Collapse
|
5
|
Ju WK, Perkins GA, Kim KY, Bastola T, Choi WY, Choi SH. Glaucomatous optic neuropathy: Mitochondrial dynamics, dysfunction and protection in retinal ganglion cells. Prog Retin Eye Res 2023; 95:101136. [PMID: 36400670 DOI: 10.1016/j.preteyeres.2022.101136] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/04/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022]
Abstract
Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by a slow, progressive, and multifactorial degeneration of retinal ganglion cells (RGCs) and their axons, resulting in vision loss. Despite its high prevalence in individuals 60 years of age and older, the causing factors contributing to glaucoma progression are currently not well characterized. Intraocular pressure (IOP) is the only proven treatable risk factor. However, lowering IOP is insufficient for preventing disease progression. One of the significant interests in glaucoma pathogenesis is understanding the structural and functional impairment of mitochondria in RGCs and their axons and synapses. Glaucomatous risk factors such as IOP elevation, aging, genetic variation, neuroinflammation, neurotrophic factor deprivation, and vascular dysregulation, are potential inducers for mitochondrial dysfunction in glaucoma. Because oxidative phosphorylation stress-mediated mitochondrial dysfunction is associated with structural and functional impairment of mitochondria in glaucomatous RGCs, understanding the underlying mechanisms and relationship between structural and functional alterations in mitochondria would be beneficial to developing mitochondria-related neuroprotection in RGCs and their axons and synapses against glaucomatous neurodegeneration. Here, we review the current studies focusing on mitochondrial dynamics-based structural and functional alterations in the mitochondria of glaucomatous RGCs and therapeutic strategies to protect RGCs against glaucomatous neurodegeneration.
Collapse
Affiliation(s)
- Won-Kyu Ju
- Hamilton Glaucoma Center and Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, CA, 92093, USA.
| | - Guy A Perkins
- National Center for Microscopy and Imaging Research, Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Keun-Young Kim
- National Center for Microscopy and Imaging Research, Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Tonking Bastola
- Hamilton Glaucoma Center and Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, CA, 92093, USA
| | - Woo-Young Choi
- Hamilton Glaucoma Center and Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, CA, 92093, USA; Department of Plastic Surgery, College of Medicine, Chosun University, Gwang-ju, South Korea
| | - Soo-Ho Choi
- Department of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| |
Collapse
|
6
|
Douglas VP, Douglas KAA, Torun N. Optical coherence tomography angiography in neuro-ophthalmology. Curr Opin Ophthalmol 2023; 34:354-360. [PMID: 37070535 DOI: 10.1097/icu.0000000000000955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
PURPOSE OF REVIEW Optical coherence tomography angiography (OCTA) is a novel, noninvasive imaging technique, which provides depth resolved visualization of microvasculature of the retina and choroid. Although OCTA has been widely used for the evaluation of a number of retinal diseases, its use in the field of neuro-ophthalmology has been less studied. In this review, we provide an update on the utility of OCTA in neuro-ophthalmic conditions. RECENT FINDINGS Peripapillary and macular microvasculature analyses have indicated that OCTA can be a promising tool for early detection of a number of neuro-ophthalmic diseases, differential diagnosis, and monitoring of disease progression. Recent studies have demonstrated that structural and functional impairment can develop at early stages in some conditions such as in multiple sclerosis and Alzheimer's disease even in the absence of overt clinical symptoms. Furthermore, this dye-less technique can be a valuable adjunct tool in the detection of complications commonly seen in some congenital entities such optic disc drusen. SUMMARY Since its introduction, OCTA has emerged as an important imaging approach shedding light on unrevealed pathophysiological mechanisms of several ocular diseases. The use of OCTA as a biomarker in the field of neuro-ophthalmology has recently gained considerable attention with studies supporting its role in clinical setting while larger studies are warranted for correlating these findings with traditional diagnostic procedures and clinical features and outcomes.
Collapse
Affiliation(s)
| | | | - Nurhan Torun
- Division of Ophthalmology, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
7
|
Evaluation of a Less Invasive Cochlear Implant Surgery in OPA1 Mutations Provoking Deafblindness. Genes (Basel) 2023; 14:genes14030627. [PMID: 36980899 PMCID: PMC10048538 DOI: 10.3390/genes14030627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/10/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
Cochlear implantation (CI) for deafblindness may have more impact than for non-syndromic hearing loss. Deafblind patients have a double handicap in a society that is more and more empowered by fast communication. CI is a remedy for deafness, but requires revision surgery every 20 to 25 years, and thus placement should be minimally invasive. Furthermore, failed reimplantation surgery will have more impact on a deafblind person. In this context, we assessed the safety of minimally invasive robotically assisted cochlear implant surgery (RACIS) for the first time in a deafblind patient. Standard pure tone audiometry and speech audiometry were performed in a patient with deafblindness as part of this robotic-assisted CI study before and after surgery. This patient, with an optic atrophy 1 (OPA1) (OMIM#165500) mutation consented to RACIS for the second (contralateral) CI. The applicability and safety of RACIS were evaluated as well as her subjective opinion on her disability. RACIS was uneventful with successful surgical and auditory outcomes in this case of deafblindness due to the OPA1 mutation. RACIS appears to be a safe and beneficial intervention to increase communication skills in the cases of deafblindness due to an OPA1 mutation. The use of RACIS use should be widespread in deafblindness as it minimizes surgical trauma and possible failures.
Collapse
|
8
|
Soldatov VO, Kubekina MV, Skorkina MY, Belykh AE, Egorova TV, Korokin MV, Pokrovskiy MV, Deykin AV, Angelova PR. Current advances in gene therapy of mitochondrial diseases. J Transl Med 2022; 20:562. [PMID: 36471396 PMCID: PMC9724384 DOI: 10.1186/s12967-022-03685-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/04/2022] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial diseases (MD) are a heterogeneous group of multisystem disorders involving metabolic errors. MD are characterized by extremely heterogeneous symptoms, ranging from organ-specific to multisystem dysfunction with different clinical courses. Most primary MD are autosomal recessive but maternal inheritance (from mtDNA), autosomal dominant, and X-linked inheritance is also known. Mitochondria are unique energy-generating cellular organelles designed to survive and contain their own unique genetic coding material, a circular mtDNA fragment of approximately 16,000 base pairs. The mitochondrial genetic system incorporates closely interacting bi-genomic factors encoded by the nuclear and mitochondrial genomes. Understanding the dynamics of mitochondrial genetics supporting mitochondrial biogenesis is especially important for the development of strategies for the treatment of rare and difficult-to-diagnose diseases. Gene therapy is one of the methods for correcting mitochondrial disorders.
Collapse
Affiliation(s)
- Vladislav O. Soldatov
- grid.4886.20000 0001 2192 9124Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia ,grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia ,grid.445984.00000 0001 2224 0652Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia ,grid.465470.4Laboratory of Biophysics of Cell Membranes under Critical State, V.A. Negovsky Scientific Research Institute of General Reanimatology, Russian Academy of Sciences, Moscow, Russia
| | - Marina V. Kubekina
- grid.4886.20000 0001 2192 9124Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Marina Yu. Skorkina
- grid.445984.00000 0001 2224 0652Department of Biochemistry, Belgorod State National Research University, Belgorod, Russia ,grid.445984.00000 0001 2224 0652Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia
| | - Andrei E. Belykh
- grid.419305.a0000 0001 1943 2944Dioscuri Centre for Metabolic Diseases, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Tatiana V. Egorova
- grid.4886.20000 0001 2192 9124Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail V. Korokin
- grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Mikhail V. Pokrovskiy
- grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Alexey V. Deykin
- grid.445984.00000 0001 2224 0652Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia ,grid.445984.00000 0001 2224 0652Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia
| | - Plamena R. Angelova
- grid.83440.3b0000000121901201Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| |
Collapse
|
9
|
Green A, Hossain T, Eckmann DM. Mitochondrial dynamics involves molecular and mechanical events in motility, fusion and fission. Front Cell Dev Biol 2022; 10:1010232. [PMID: 36340034 PMCID: PMC9626967 DOI: 10.3389/fcell.2022.1010232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/06/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondria are cell organelles that play pivotal roles in maintaining cell survival, cellular metabolic homeostasis, and cell death. Mitochondria are highly dynamic entities which undergo fusion and fission, and have been shown to be very motile in vivo in neurons and in vitro in multiple cell lines. Fusion and fission are essential for maintaining mitochondrial homeostasis through control of morphology, content exchange, inheritance of mitochondria, maintenance of mitochondrial DNA, and removal of damaged mitochondria by autophagy. Mitochondrial motility occurs through mechanical and molecular mechanisms which translocate mitochondria to sites of high energy demand. Motility also plays an important role in intracellular signaling. Here, we review key features that mediate mitochondrial dynamics and explore methods to advance the study of mitochondrial motility as well as mitochondrial dynamics-related diseases and mitochondrial-targeted therapeutics.
Collapse
Affiliation(s)
- Adam Green
- Department of Anesthesiology, The Ohio State University, Columbus, OH, United States
| | - Tanvir Hossain
- Department of Anesthesiology, The Ohio State University, Columbus, OH, United States
| | - David M. Eckmann
- Department of Anesthesiology, The Ohio State University, Columbus, OH, United States
- Center for Medical and Engineering Innovation, The Ohio State University, Columbus, OH, United States
- *Correspondence: David M. Eckmann,
| |
Collapse
|
10
|
Charif M, Chevrollier A, Gueguen N, Kane S, Bris C, Goudenège D, Desquiret-Dumas V, Meunier I, Mochel F, Jeanjean L, Varenne F, Procaccio V, Reynier P, Bonneau D, Amati-Bonneau P, Lenaers G. Next-Generation Sequencing Identifies Novel PMPCA Variants in Patients with Late-Onset Dominant Optic Atrophy. Genes (Basel) 2022; 13:1202. [PMID: 35885985 PMCID: PMC9320445 DOI: 10.3390/genes13071202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/11/2022] [Accepted: 07/01/2022] [Indexed: 02/01/2023] Open
Abstract
Dominant Optic Atrophy (DOA) is one of the most common inherited mitochondrial diseases, leading to blindness. It is caused by the chronic degeneration of the retinal ganglion cells (RGCs) and their axons forming the optic nerve. Until now, DOA has been mainly associated with genes encoding proteins involved in mitochondrial network dynamics. Using next-generation and exome sequencing, we identified for the first time heterozygous PMPCA variants having a causative role in the pathology of late-onset primary DOA in five patients. PMPCA encodes an α subunit of the mitochondrial peptidase (MPP), responsible for the cleavage and maturation of the mitochondrial precursor proteins imported from the cytoplasm into mitochondria. Recently, PMPCA has been identified as the gene responsible for Autosomal Recessive Cerebellar Ataxia type 2 (SCAR2) and another severe recessive mitochondrial disease. In this study, four PMPCA variants were identified, two are frameshifts (c.309delA and c.820delG) classified as pathogenic and two are missenses (c.1363G>A and c.1547G>A) classified with uncertain pathological significance. Functional assays on patients’ fibroblasts show a hyperconnection of the mitochondrial network and revealed that frameshift variants reduced α-MPP levels, while not significantly affecting the respiratory machinery. These results suggest that alterations in mitochondrial peptidase function can affect the fusion-fission balance, a key element in maintaining the physiology of retinal ganglion cells, and consequently lead to their progressive degeneration.
Collapse
Affiliation(s)
- Majida Charif
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Genetics and Immuno-Cell Therapy Team, Mohammed First University, Oujda 60000, Morocco
| | - Arnaud Chevrollier
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
| | - Naïg Gueguen
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Biochemistry and Molecular Biology, University Hospital Angers, 49933 Angers, France
| | - Selma Kane
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
| | - Céline Bris
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Biochemistry and Molecular Biology, University Hospital Angers, 49933 Angers, France
| | - David Goudenège
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Biochemistry and Molecular Biology, University Hospital Angers, 49933 Angers, France
| | - Valerie Desquiret-Dumas
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Biochemistry and Molecular Biology, University Hospital Angers, 49933 Angers, France
| | - Isabelle Meunier
- National Reference Centre for Inherited Sensory Diseases, University Hospital of Montpellier, University of Montpellier, 34000 Montpellier, France;
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34000 Montpellier, France
| | - Fanny Mochel
- Department of Genetics, AP-HP, Pitié-Salpêtrière University Hospital, 75013 Paris, France;
| | - Luc Jeanjean
- Department of Ophthalmology, Nîmes University Hospital, CEDEX 9, 30900 Nîmes, France;
| | - Fanny Varenne
- Department of Ophthalmology, Hôpital Pierre Paul Riquet CHU Purpan, 31300 Toulouse, France;
| | - Vincent Procaccio
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Genetics, University Hospital Angers, 49933 Angers, France
| | - Pascal Reynier
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Biochemistry and Molecular Biology, University Hospital Angers, 49933 Angers, France
| | - Dominique Bonneau
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Genetics, University Hospital Angers, 49933 Angers, France
| | - Patrizia Amati-Bonneau
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Departments of Biochemistry and Molecular Biology, University Hospital Angers, 49933 Angers, France
| | - Guy Lenaers
- MitoLab Team, UMR CNRS 6015-INSERM U1083, Institut MitoVasc, SFR ICAT, Université d’Angers, 49933 Angers, France; (M.C.); (A.C.); (N.G.); (S.K.); (C.B.); (D.G.); (V.D.-D.); (V.P.); (P.R.); (D.B.); (P.A.-B.)
- Service de Neurologie, University Hospital Angers, 49933 Angers, France
| |
Collapse
|
11
|
Zehden JA, Raviskanthan S, Mortensen PW, Ferré M, Reynier P, Milea D, Lee AG. Dominant Optic Atrophy: How to Determine the Pathogenicity of Novel Variants? J Neuroophthalmol 2022; 42:149-153. [PMID: 34629404 DOI: 10.1097/wno.0000000000001352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Jason A Zehden
- Baylor College of Medicine (JZ), Houston, Texas, US; Department of Ophthalmology (SR, PWM, AGL), Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas; MITOVASC Institute (MF, PR, DM), CNRS 6015, INSERM U1083, University of Angers, France ; Singapore National Eye Center (DM), Singapore, Singapore ; Singapore Eye Research Institute (DM), Singapore, Singapore ; Duke-NUS Medical School (DM), Singapore, Singapore ; Copenhagen University Hospital Denmark (DM), Copenhagen, Denmark; Departments of Ophthalmology (AGL), Neurology, and Neurosurgery, Weill Cornell Medicine, New York, New York; Department of Ophthalmology (AGL), University of Texas Medical Branch, Galveston, Texas; University of Texas MD Anderson Cancer Center (AGL), Houston, Texas; Texas A and M College of Medicine (AGL), Bryan, Texas; and Department of Ophthalmology (AGL), The University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | | | | | | | | | | | | |
Collapse
|
12
|
First Description of Inheritance of a Postzygotic OPA1 Mosaic Variant. Genes (Basel) 2022; 13:genes13030478. [PMID: 35328032 PMCID: PMC8948733 DOI: 10.3390/genes13030478] [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: 12/21/2021] [Revised: 02/08/2022] [Accepted: 03/04/2022] [Indexed: 12/02/2022] Open
Abstract
Optic atrophy 1 (MIM #165500) is caused by pathogenic variants in the gene OPA1 (OPA1 MITOCHONDRIAL DYNAMIN-LIKE GTPase, MIM *605290) and is inherited in an autosomal dominant manner. We describe a 6-year-old male patient with severe early onset manifestation of optic atrophy, whose parents are subjectively asymptomatic. OPA1-sequence analysis revealed the heterozygous missense variant NM_015560.3:c.806C>T, p.(Ser269Phe) in the patient. Segregation analysis of the parents showed that the mother carried a low-grade postzygotic mosaic of this variant, which apparently also involves germline cells. In line with this, ophthalmological investigation of the mother showed subclinical manifestation of optic atrophy 1. This is the first report of an OPA1 postzygotic mosaic that was inherited to offspring.
Collapse
|
13
|
Ying P, Huang C, Wang Y, Guo X, Cao Y, Zhang Y, Fu S, Chen L, Yi G, Fu M. Single-Cell RNA Sequencing of Retina:New Looks for Gene Marker and Old Diseases. Front Mol Biosci 2021; 8:699906. [PMID: 34395530 PMCID: PMC8362665 DOI: 10.3389/fmolb.2021.699906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 07/01/2021] [Indexed: 01/20/2023] Open
Abstract
The retina is composed of 11 types of cells, including neurons, glial cells and vascular bed cells. It contains five types of neurons, each with specific physiological, morphological, and molecular definitions. Currently, single-cell RNA sequencing (sRNA-seq) is emerging as one of the most powerful tools to reveal the complexity of the retina. The continuous discovery of retina-related gene targets plays an important role in helping us understand the nature of diseases. The revelation of new cell subpopulations can focus the occurrence and development of diseases on specific biological activities of specific cells. In addition, sRNA-seq performs high-throughput sequencing analysis of epigenetics, transcriptome and genome at the single-cell level, with the advantages of high-throughput and high-resolution. In this paper, we systematically review the development history of sRNA-seq technology, and summarize the new subtypes of retinal cells and some specific gene markers discovered by this technology. The progress in the diagnosis of retinal related diseases is also discussed.
Collapse
Affiliation(s)
- Peixi Ying
- The Second Clinical School, Southern Medical University, Guangzhou, China
| | - Chang Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Yan Wang
- Department of Ophthalmology, South China Hospital, Health Science Center, Shenzhen University, Shenzhen, China
| | - Xi Guo
- Medical College of Rehabiliation, Southern Medical University, Guangzhou, China
| | - Yuchen Cao
- The Second Clinical School, Southern Medical University, Guangzhou, China
| | - Yuxi Zhang
- The Second Clinical School, Southern Medical University, Guangzhou, China
| | - Sheng Fu
- The University of South China, Hengyang, China
| | - Lin Chen
- Department of Anesthesiology, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Guoguo Yi
- Department of Ophthalmology, the Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Min Fu
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| |
Collapse
|
14
|
Lenaers G, Neutzner A, Le Dantec Y, Jüschke C, Xiao T, Decembrini S, Swirski S, Kieninger S, Agca C, Kim US, Reynier P, Yu-Wai-Man P, Neidhardt J, Wissinger B. Dominant optic atrophy: Culprit mitochondria in the optic nerve. Prog Retin Eye Res 2021; 83:100935. [PMID: 33340656 DOI: 10.1016/j.preteyeres.2020.100935] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 12/05/2020] [Accepted: 12/09/2020] [Indexed: 12/14/2022]
Abstract
Dominant optic atrophy (DOA) is an inherited mitochondrial disease leading to specific degeneration of retinal ganglion cells (RGCs), thus compromising transmission of visual information from the retina to the brain. Usually, DOA starts during childhood and evolves to poor vision or legal blindness, affecting the central vision, whilst sparing the peripheral visual field. In 20% of cases, DOA presents as syndromic disorder, with secondary symptoms affecting neuronal and muscular functions. Twenty years ago, we demonstrated that heterozygous mutations in OPA1 are the most frequent molecular cause of DOA. Since then, variants in additional genes, whose functions in many instances converge with those of OPA1, have been identified by next generation sequencing. OPA1 encodes a dynamin-related GTPase imported into mitochondria and located to the inner membrane and intermembrane space. The many OPA1 isoforms, resulting from alternative splicing of three exons, form complex homopolymers that structure mitochondrial cristae, and contribute to fusion of the outer membrane, thus shaping the whole mitochondrial network. Moreover, OPA1 is required for oxidative phosphorylation, maintenance of mitochondrial genome, calcium homeostasis and regulation of apoptosis, thus making OPA1 the Swiss army-knife of mitochondria. Understanding DOA pathophysiology requires the understanding of RGC peculiarities with respect to OPA1 functions. Besides the tremendous energy requirements of RGCs to relay visual information from the eye to the brain, these neurons present unique features related to their differential environments in the retina, and to the anatomical transition occurring at the lamina cribrosa, which parallel major adaptations of mitochondrial physiology and shape, in the pre- and post-laminar segments of the optic nerve. Three DOA mouse models, with different Opa1 mutations, have been generated to study intrinsic mechanisms responsible for RGC degeneration, and these have further revealed secondary symptoms related to mitochondrial dysfunctions, mirroring the more severe syndromic phenotypes seen in a subgroup of patients. Metabolomics analyses of cells, mouse organs and patient plasma mutated for OPA1 revealed new unexpected pathophysiological mechanisms related to mitochondrial dysfunction, and biomarkers correlated quantitatively to the severity of the disease. Here, we review and synthesize these data, and propose different approaches for embracing possible therapies to fulfil the unmet clinical needs of this disease, and provide hope to affected DOA patients.
Collapse
Affiliation(s)
- Guy Lenaers
- MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, Angers University and Hospital, Angers, France.
| | - Albert Neutzner
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Department of Ophthalmology University Hospital Basel, University of Basel, Basel, Switzerland.
| | - Yannick Le Dantec
- MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, Angers University and Hospital, Angers, France
| | - Christoph Jüschke
- Human Genetics, Faculty VI - School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Ting Xiao
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Sarah Decembrini
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Department of Ophthalmology University Hospital Basel, University of Basel, Basel, Switzerland
| | - Sebastian Swirski
- Human Genetics, Faculty VI - School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Sinja Kieninger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Cavit Agca
- Molecular Biology, Genetics and Bioengineering Program, Sabanci University, Istanbul, Turkey; Nanotechnology Research and Application Center (SUNUM), Sabanci University, Istanbul, Turkey
| | - Ungsoo S Kim
- Kim's Eye Hospital, Seoul, South Korea; Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital, London, UK
| | - Pascal Reynier
- MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, Angers University and Hospital, Angers, France; Department of Biochemistry, University Hospital of Angers, Angers, France
| | - Patrick Yu-Wai-Man
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital, London, UK; UCL Institute of Ophthalmology, University College London, London, UK
| | - John Neidhardt
- Human Genetics, Faculty VI - School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany; Research Center Neurosensory Science, University Oldenburg, Oldenburg, Germany.
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany.
| |
Collapse
|
15
|
Soldatov VO, Kukharsky MS, Belykh AE, Sobolev AM, Deykin AV. Retinal Damage in Amyotrophic Lateral Sclerosis: Underlying Mechanisms. Eye Brain 2021; 13:131-146. [PMID: 34012311 PMCID: PMC8128130 DOI: 10.2147/eb.s299423] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/04/2021] [Indexed: 01/04/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease resulting in a gradual loss of motor neuron function. Although ophthalmic complaints are not presently considered a classic symptom of ALS, retinal changes such as thinning, axonal degeneration and inclusion bodies have been found in many patients. Retinal abnormalities observed in postmortem human tissues and animal models are similar to spinal cord changes in ALS. These findings are not dramatically unexpected because retina shares an ontogenetic relationship with the brain, and many genes are associated both with neurodegeneration and retinal diseases. Experimental studies have demonstrated that ALS affects many “vulnerable points” of the retina. Aggregate deposition, impaired nuclear protein import, endoplasmic reticulum stress, glutamate excitotoxicity, vascular regression, and mitochondrial dysfunction are factors suspected as being the main cause of motor neuron damage in ALS. Herein, we show that all of these pathways can affect retinal cells in the same way as motor neurons. Furthermore, we suppose that understanding the patterns of neuro-ophthalmic interaction in ALS can help in the diagnosis and treatment of this disease.
Collapse
Affiliation(s)
- Vladislav O Soldatov
- Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Michail S Kukharsky
- Department of General and Cell Biology, Faculty of Medical Biology, Pirogov Russian National Research Medical University, Moscow, Russia.,Laboratory of Genetic Modelling of Neurodegenerative Processes, Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Russia
| | - Andrey E Belykh
- Department of Pathophysiology, Kursk State Medical University, Kursk, Russia
| | - Andrey M Sobolev
- Laboratory of Genetic Modelling of Neurodegenerative Processes, Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Russia
| | - Alexey V Deykin
- Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
16
|
Hereditary Optic Neuropathies: Induced Pluripotent Stem Cell-Based 2D/3D Approaches. Genes (Basel) 2021; 12:genes12010112. [PMID: 33477675 PMCID: PMC7831942 DOI: 10.3390/genes12010112] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/10/2021] [Accepted: 01/14/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited optic neuropathies share visual impairment due to the degeneration of retinal ganglion cells (RGCs) as the hallmark of the disease. This group of genetic disorders are caused by mutations in nuclear genes or in the mitochondrial DNA (mtDNA). An impaired mitochondrial function is the underlying mechanism of these diseases. Currently, optic neuropathies lack an effective treatment, and the implementation of induced pluripotent stem cell (iPSC) technology would entail a huge step forward. The generation of iPSC-derived RGCs would allow faithfully modeling these disorders, and these RGCs would represent an appealing platform for drug screening as well, paving the way for a proper therapy. Here, we review the ongoing two-dimensional (2D) and three-dimensional (3D) approaches based on iPSCs and their applications, taking into account the more innovative technologies, which include tissue engineering or microfluidics.
Collapse
|
17
|
Bottani E, Lamperti C, Prigione A, Tiranti V, Persico N, Brunetti D. Therapeutic Approaches to Treat Mitochondrial Diseases: "One-Size-Fits-All" and "Precision Medicine" Strategies. Pharmaceutics 2020; 12:E1083. [PMID: 33187380 PMCID: PMC7696526 DOI: 10.3390/pharmaceutics12111083] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Primary mitochondrial diseases (PMD) refer to a group of severe, often inherited genetic conditions due to mutations in the mitochondrial genome or in the nuclear genes encoding for proteins involved in oxidative phosphorylation (OXPHOS). The mutations hamper the last step of aerobic metabolism, affecting the primary source of cellular ATP synthesis. Mitochondrial diseases are characterized by extremely heterogeneous symptoms, ranging from organ-specific to multisystemic dysfunction with different clinical courses. The limited information of the natural history, the limitations of currently available preclinical models, coupled with the large variability of phenotypical presentations of PMD patients, have strongly penalized the development of effective therapies. However, new therapeutic strategies have been emerging, often with promising preclinical and clinical results. Here we review the state of the art on experimental treatments for mitochondrial diseases, presenting "one-size-fits-all" approaches and precision medicine strategies. Finally, we propose novel perspective therapeutic plans, either based on preclinical studies or currently used for other genetic or metabolic diseases that could be transferred to PMD.
Collapse
Affiliation(s)
- Emanuela Bottani
- Department of Diagnostics and Public Health, Section of Pharmacology, University of Verona, 37134 Verona, Italy
| | - Costanza Lamperti
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico C. Besta, 20126 Milan, Italy; (C.L.); (V.T.)
| | - Alessandro Prigione
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, University Clinic Düsseldorf (UKD), Heinrich Heine University (HHU), 40225 Dusseldorf, Germany;
| | - Valeria Tiranti
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico C. Besta, 20126 Milan, Italy; (C.L.); (V.T.)
| | - Nicola Persico
- Department of Clinical Science and Community Health, University of Milan, 20122 Milan, Italy;
- Fetal Medicine and Surgery Service, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Dario Brunetti
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico C. Besta, 20126 Milan, Italy; (C.L.); (V.T.)
- Department of Medical Biotechnology and Translational Medicine, University of Milan, 20129 Milan, Italy
| |
Collapse
|
18
|
Yan W, Peng YR, van Zyl T, Regev A, Shekhar K, Juric D, Sanes JR. Cell Atlas of The Human Fovea and Peripheral Retina. Sci Rep 2020; 10:9802. [PMID: 32555229 PMCID: PMC7299956 DOI: 10.1038/s41598-020-66092-9] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/12/2020] [Indexed: 01/28/2023] Open
Abstract
Most irreversible blindness results from retinal disease. To advance our understanding of the etiology of blinding diseases, we used single-cell RNA-sequencing (scRNA-seq) to analyze the transcriptomes of ~85,000 cells from the fovea and peripheral retina of seven adult human donors. Utilizing computational methods, we identified 58 cell types within 6 classes: photoreceptor, horizontal, bipolar, amacrine, retinal ganglion and non-neuronal cells. Nearly all types are shared between the two retinal regions, but there are notable differences in gene expression and proportions between foveal and peripheral cohorts of shared types. We then used the human retinal atlas to map expression of 636 genes implicated as causes of or risk factors for blinding diseases. Many are expressed in striking cell class-, type-, or region-specific patterns. Finally, we compared gene expression signatures of cell types between human and the cynomolgus macaque monkey, Macaca fascicularis. We show that over 90% of human types correspond transcriptomically to those previously identified in macaque, and that expression of disease-related genes is largely conserved between the two species. These results validate the use of the macaque for modeling blinding disease, and provide a foundation for investigating molecular mechanisms underlying visual processing.
Collapse
Affiliation(s)
- Wenjun Yan
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA
| | - Yi-Rong Peng
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA
- Department of Ophthalmology, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Tavé van Zyl
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear, Boston, MA, 02114, USA
| | - Aviv Regev
- Howard Hughes Medical Institute, Koch Institute of Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02140; and Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Karthik Shekhar
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA
- Howard Hughes Medical Institute, Koch Institute of Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02140; and Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
- Department of Chemical and Biomolecular Engineering and Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Dejan Juric
- Massachusetts General Hospital Cancer Center, Department of Medicine, Harvard Medical School, Boston, USA
| | - Joshua R Sanes
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA.
| |
Collapse
|
19
|
Le Roux B, Lenaers G, Zanlonghi X, Amati-Bonneau P, Chabrun F, Foulonneau T, Caignard A, Leruez S, Gohier P, Procaccio V, Milea D, den Dunnen JT, Reynier P, Ferré M. OPA1: 516 unique variants and 831 patients registered in an updated centralized Variome database. Orphanet J Rare Dis 2019; 14:214. [PMID: 31500643 PMCID: PMC6734442 DOI: 10.1186/s13023-019-1187-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The dysfunction of OPA1, a dynamin GTPase involved in mitochondrial fusion, is responsible for a large spectrum of neurological disorders, each of which includes optic neuropathy. The database dedicated to OPA1 ( https://www.lovd.nl/OPA1 ), created in 2005, has now evolved towards a centralized and more reliable database using the Global Variome shared Leiden Open-source Variation Database (LOVD) installation. RESULTS The updated OPA1 database, which registers all the patients from our center as well as those reported in the literature, now covers a total of 831 patients: 697 with isolated dominant optic atrophy (DOA), 47 with DOA "plus", and 83 with asymptomatic or unclassified DOA. It comprises 516 unique OPA1 variants, of which more than 80% (414) are considered pathogenic. Full clinical data for 118 patients are documented using the Human Phenotype Ontology, a standard vocabulary for referencing phenotypic abnormalities. Contributors may now make online submissions of phenotypes related to OPA1 mutations, giving clinical and molecular descriptions together with detailed ophthalmological and neurological data, according to an international thesaurus. CONCLUSIONS The evolution of the OPA1 database towards the LOVD, using unified nomenclature, should ensure its interoperability with other databases and prove useful for molecular diagnoses based on gene-panel sequencing, large-scale mutation statistics, and genotype-phenotype correlations.
Collapse
Affiliation(s)
- Bastien Le Roux
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Guy Lenaers
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France
| | - Xavier Zanlonghi
- Centre de Compétence Maladie Rare, Clinique Jules Verne, Nantes, France
| | - Patrizia Amati-Bonneau
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Floris Chabrun
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Thomas Foulonneau
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France
| | - Angélique Caignard
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Stéphanie Leruez
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Philippe Gohier
- Département d'Ophtalmologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Vincent Procaccio
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Dan Milea
- Singapore National Eye Center, Singapore Eye Research Institute, Duke-NUS, Singapore, Singapore
| | - Johan T den Dunnen
- Human Genetics and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Pascal Reynier
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Marc Ferré
- Unité Mixte de Recherche MITOVASC, CNRS 6015/INSERM 1083, Université d'Angers, Angers, France.
| |
Collapse
|
20
|
Hou H, Wang Y, Li Q, Li Z, Teng Y, Li J, Wang X, Chen J, Huang N. The role of RIP3 in cardiomyocyte necrosis induced by mitochondrial damage of myocardial ischemia-reperfusion. Acta Biochim Biophys Sin (Shanghai) 2018; 50:1131-1140. [PMID: 30215665 DOI: 10.1093/abbs/gmy108] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Indexed: 11/13/2022] Open
Abstract
Myocardial damage caused by myocardial ischemia-reperfusion injury (MIRI) is difficult to be alleviated because cardiomyocyte necrosis is an irreversible and unregulated death form. Recently, necroptosis, a necrosis form caused by tumor necrosis factor-α (TNF-α) and Fas ligand (FasL), was found to be regulated by receptor interacting protein 3 (RIP3) and RIP3-receptor interacting protein 1 (RIP1)-mixed lineage kinase domain like protein (MLKL) pathway. But it is unclear whether they also play a regulatory role in MIRI-induced necroptosis. Our previous results showed that in rat MIRI, RIP3 could translocate and express highly in mitochondria. Therefore, it is important to explore proteins that interact with RIP3 which was translocated to mitochondria. The aim of this study was to explore the role of RIP3 in cardiomyocyte necrosis induced by mitochondrial damage of hypoxia/reoxygenation (H/R). Our results showed that H/R could cause RIP3-depended mitochondrial fragmentation and necrosis-based death; and RIP3-promoted H/R-induced necroptosis in H9c2 cells through increasing lactate dehydrogenase release and inhibiting cell viability. This process did not require RIP1 or MLKL but dynamin-related protein 1 (Drp1), which was related to Drp1 activation, reactive oxygen species elevation, and ΔΨm decline. This study provides novel insights into the role of RIP3 in cardiomyocyte injury during H/R. RIP3 may serve as a potential target for the treatment of MIRI.
Collapse
Affiliation(s)
- Huifang Hou
- Department of Pathophysiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
- Department of Pathophysiology, Xinxiang Medical University, Xinxiang, China
| | - Yongling Wang
- Department of Pathophysiology, Xinxiang Medical University, Xinxiang, China
| | - Qiong Li
- School of Nursing, Xinxiang Medical University, Xinxiang, China
| | - Zaibing Li
- Department of Pathophysiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Yan Teng
- Department of Pathophysiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Jingyu Li
- Department of Pathophysiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Xiaoying Wang
- Department of Pathophysiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Junli Chen
- Department of Pathophysiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Ning Huang
- Department of Pathophysiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| |
Collapse
|
21
|
Parisi V, Oddone F, Ziccardi L, Roberti G, Coppola G, Manni G. Citicoline and Retinal Ganglion Cells: Effects on Morphology and Function. Curr Neuropharmacol 2018; 16:919-932. [PMID: 28676014 PMCID: PMC6120106 DOI: 10.2174/1570159x15666170703111729] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/07/2017] [Accepted: 06/22/2017] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Retinal ganglion cells (RGCs) are the nervous retinal elements which connect the visual receptors to the brain forming the nervous visual system. Functional and/or morphological involvement of RGCs occurs in several ocular and neurological disorders and therefore these cells are targeted in neuroprotective strategies. Cytidine 5-diphosphocholine or Citicoline is an endogenous compound that acts in the biosynthesis of phospholipids of cell membranes and increases neurotransmitters' levels in the Central Nervous System. Experimental studies suggested the neuromodulator effect and the protective role of Citicoline on RGCs. This review aims to present evidence of the effects of Citicoline in experimental models of RGCs degeneration and in human neurodegenerative disorders involving RGCs. METHODS All published papers containing experimental or clinical studies about the effects of Citicoline on RGCs morphology and function were reviewed. RESULTS In rodent retinal cultures and animal models, Citicoline induces antiapoptotic effects, increases the dopamine retinal level, and counteracts retinal nerve fibers layer thinning. Human studies in neurodegenerative visual pathologies such as glaucoma or non-arteritic ischemic neuropathy showed a reduction of the RGCs impairment after Citicoline administration. By reducing the RGCs' dysfunction, a better neural conduction along the post-retinal visual pathways with an improvement of the visual field defects was observed. CONCLUSION Citicoline, with a solid history of experimental and clinical studies, could be considered a very promising molecule for neuroprotective strategies in those pathologies (i.e. Glaucoma) in which morpho-functional changes of RGCc occurs.
Collapse
Affiliation(s)
- Vincenzo Parisi
- IRCCS-Fondazione GB Bietti, Via Livenza, 3, 00198 Rome, Italy
| | | | - Lucia Ziccardi
- IRCCS-Fondazione GB Bietti, Via Livenza, 3, 00198 Rome, Italy
| | - Gloria Roberti
- IRCCS-Fondazione GB Bietti, Via Livenza, 3, 00198 Rome, Italy
| | | | - Gianluca Manni
- IRCCS-Fondazione GB Bietti, Via Livenza, 3, 00198 Rome, Italy.,DSCMT, Università di Roma Tor Vergata, Viale Oxford 81, 00133 Rome, Italy
| |
Collapse
|
22
|
Abrams AJ, Fontanesi F, Tan NBL, Buglo E, Campeanu IJ, Rebelo AP, Kornberg AJ, Phelan DG, Stark Z, Zuchner S. Insights into the genotype-phenotype correlation and molecular function of SLC25A46. Hum Mutat 2018; 39:1995-2007. [PMID: 30178502 DOI: 10.1002/humu.23639] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 01/08/2023]
Abstract
Recessive SLC25A46 mutations cause a spectrum of neurodegenerative disorders with optic atrophy as a core feature. We report a patient with optic atrophy, peripheral neuropathy, ataxia, but not cerebellar atrophy, who is on the mildest end of the phenotypic spectrum. By studying seven different nontruncating mutations, we found that the stability of the SLC25A46 protein inversely correlates with the severity of the disease and the patient's variant does not markedly destabilize the protein. SLC25A46 belongs to the mitochondrial transporter family, but it is not known to have transport function. Apart from this possible function, SLC25A46 forms molecular complexes with proteins involved in mitochondrial dynamics and cristae remodeling. We demonstrate that the patient's mutation directly affects the SLC25A46 interaction with MIC60. Furthermore, we mapped all of the reported substitutions in the protein onto a 3D model and found that half of them fall outside of the signature carrier motifs associated with transport function. We thus suggest that there are two distinct molecular mechanisms in SLC25A46-associated pathogenesis, one that destabilizes the protein while the other alters the molecular interactions of the protein. These results have the potential to inform clinical prognosis of such patients and indicate a pathway to drug target development.
Collapse
Affiliation(s)
- Alexander J Abrams
- John P. Hussman Institute for Human Genomics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, Florida, USA
| | - Flavia Fontanesi
- Department of Biochemistry and Molecular Biology, University of Miami, Miami, Florida, USA
| | - Natalie B L Tan
- Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Elena Buglo
- John P. Hussman Institute for Human Genomics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, Florida, USA
| | - Ion J Campeanu
- Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Adriana P Rebelo
- John P. Hussman Institute for Human Genomics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, Florida, USA
| | - Andrew J Kornberg
- Department of Neurology, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Dean G Phelan
- Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Zornitza Stark
- Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Stephan Zuchner
- John P. Hussman Institute for Human Genomics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, Florida, USA
| |
Collapse
|
23
|
Martín-Jiménez R, Faccenda D, Allen E, Reichel HB, Arcos L, Ferraina C, Strobbe D, Russell C, Campanella M. Reduction of the ATPase inhibitory factor 1 (IF 1) leads to visual impairment in vertebrates. Cell Death Dis 2018; 9:669. [PMID: 29867190 PMCID: PMC5986772 DOI: 10.1038/s41419-018-0578-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/21/2018] [Accepted: 03/27/2018] [Indexed: 12/12/2022]
Abstract
In vertebrates, mitochondria are tightly preserved energy producing organelles, which sustain nervous system development and function. The understanding of proteins that regulate their homoeostasis in complex animals is therefore critical and doing so via means of systemic analysis pivotal to inform pathophysiological conditions associated with mitochondrial deficiency. With the goal to decipher the role of the ATPase inhibitory factor 1 (IF1) in brain development, we employed the zebrafish as elected model reporting that the Atpif1a-/- zebrafish mutant, pinotage (pnt tq209 ), which lacks one of the two IF1 paralogous, exhibits visual impairment alongside increased apoptotic bodies and neuroinflammation in both brain and retina. This associates with increased processing of the dynamin-like GTPase optic atrophy 1 (OPA1), whose ablation is a direct cause of inherited optic atrophy. Defects in vision associated with the processing of OPA1 are specular in Atpif1-/- mice thus confirming a regulatory axis, which interlinks IF1 and OPA1 in the definition of mitochondrial fitness and specialised brain functions. This study unveils a functional relay between IF1 and OPA1 in central nervous system besides representing an example of how the zebrafish model could be harnessed to infer the activity of mitochondrial proteins during development.
Collapse
Affiliation(s)
- Rebeca Martín-Jiménez
- Department of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, London, United Kingdom
| | - Danilo Faccenda
- Department of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, London, United Kingdom
- Department of Biology, University of Rome Tor Vergata, 00144, Rome, Italy
| | - Emma Allen
- Department of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, London, United Kingdom
| | - Holly Beatrice Reichel
- Department of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, London, United Kingdom
| | - Laura Arcos
- Department of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, London, United Kingdom
| | - Caterina Ferraina
- Department of Biology, University of Rome Tor Vergata, 00144, Rome, Italy
- IRCCS- Regina Elena, National Cancer Institute, 00133, Rome, Italy
| | - Daniela Strobbe
- Department of Biology, University of Rome Tor Vergata, 00144, Rome, Italy
| | - Claire Russell
- Department of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, London, United Kingdom
| | - Michelangelo Campanella
- Department of Comparative Biomedical Sciences, Royal Veterinary College, NW1 0TU, London, United Kingdom.
- IRCCS- Regina Elena, National Cancer Institute, 00133, Rome, Italy.
- University College London Consortium for Mitochondrial Research, University College London, WC1 6BT, London, United Kingdom.
| |
Collapse
|
24
|
Corajevic N, Larsen M, Rönnbäck C. Thickness mapping of individual retinal layers and sectors by Spectralis SD-OCT in Autosomal Dominant Optic Atrophy. Acta Ophthalmol 2018; 96:251-256. [PMID: 29091347 DOI: 10.1111/aos.13588] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 08/11/2017] [Indexed: 01/06/2023]
Abstract
PURPOSE To assess layer- and location-specific retinal thickness deficits in autosomal dominant optic atrophy (ADOA) using Spectralis SD-OCT. METHODS This cross-sectional study included 41 ADOA patients with OPA1 exon 28 (2826delT) mutation [age, 8.6-83.5 years; best-corrected visual acuity (BCVA), 8-89 Early Treatment Diabetic Retinopathy Study (ETDRS) letters] and 55 mutation-free first-degree relatives as healthy controls (age, 8.9-68.7; BCVA, 80-99). Participants underwent routine examination and optical coherence tomography (OCT) with segmentation of the whole retina, inner retinal layers (IRL) and outer retinal layers (ORL). Individual segmentation was performed of the perifoveal retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigment epithelium (RPE) and the peripapillary RNFL. Combinations of layers and sectors were tested for their diagnostic significance. Only right eye data are presented. Statistical analysis was adjusted for age, gender, spherical equivalent, axial length and family clustering in a mixed model analysis. RESULTS The perifoveal RNFL, GCL, IPL and the peripapillary RNFL were all significantly thinner in ADOA patients than in healthy controls (p < 0.0001). No statistical difference was found for other layers. The most prominent and diagnostically most valuable deficit was found in the GCL (-49.9%) in the 'nasal inner macula' (NIM) sector (-63%). Attenuation of the peripapillary RNFL was most significant in the temporal sector (-58.4%). CONCLUSION In ADOA, retinal ganglion cells are most prominently reduced in the nasal perifoveal area of the GCL, which together with the temporal peripapillary RNFL area serves as the strongest diagnostic OCT marker.
Collapse
Affiliation(s)
- Nihada Corajevic
- Department of Ophthalmology; Glostrup Hospital; Copenhagen Denmark
| | - Michael Larsen
- Department of Ophthalmology; Glostrup Hospital; Copenhagen Denmark
| | - Cecilia Rönnbäck
- Department of Ophthalmology; Glostrup Hospital; Copenhagen Denmark
| |
Collapse
|
25
|
Jackson JG, Robinson MB. Regulation of mitochondrial dynamics in astrocytes: Mechanisms, consequences, and unknowns. Glia 2017; 66:1213-1234. [PMID: 29098734 DOI: 10.1002/glia.23252] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 09/20/2017] [Accepted: 10/09/2017] [Indexed: 12/15/2022]
Abstract
Astrocytes are the major glial cell in the central nervous system. These polarized cells possess numerous processes that ensheath the vasculature and contact synapses. Astrocytes play important roles in synaptic signaling, neurotransmitter synthesis and recycling, control of nutrient uptake, and control of local blood flow. Many of these processes depend on local metabolism and/or energy utilization. While astrocytes respond to increases in neuronal activity and metabolic demand by upregulating glycolysis and glycogenolysis, astrocytes also possess significant capacity for oxidative (mitochondrial) metabolism. Mitochondria mediate energy supply and metabolism, cellular survival, ionic homeostasis, and proliferation. These organelles are dynamic structures undergoing extensive fission and fusion, directed movement along cytoskeletal tracts, and degradation. While many of the mechanisms underlying the dynamics of these organelles and their physiologic roles have been characterized in neurons and other cells, the roles that mitochondrial dynamics play in glial physiology is less well understood. Recent work from several laboratories has demonstrated that mitochondria are present within the fine processes of astrocytes, that their movement is regulated, and that they contribute to local Ca2+ signaling within the astrocyte. They likely play a role in local ATP production and metabolism, particularly that of glutamate. Here we will review these and other findings describing the mechanism by which mitochondrial dynamics are regulated in astrocytes, how mitochondrial dynamics might influence astrocyte and brain metabolism, and draw parallels to mitochondrial dynamics in neurons. Additionally, we present new analyses of the size, distribution, and dynamics of mitochondria in astrocytes performed using in vivo using 2-photon microscopy.
Collapse
Affiliation(s)
- Joshua G Jackson
- Children's Hospital of Philadelphia Research Institute, University of Pennsylvania, Philadelphia, PA, 19104.,Departments of Pediatrics, University of Pennsylvania, Philadelphia, PA, 19104
| | - Michael B Robinson
- Children's Hospital of Philadelphia Research Institute, University of Pennsylvania, Philadelphia, PA, 19104.,Departments of Pediatrics, University of Pennsylvania, Philadelphia, PA, 19104.,Department of Pharmacology, University of Pennsylvania, Philadelphia, PA, 19104
| |
Collapse
|
26
|
Neuro-Ophthalmic Manifestations of Pediatric Neurodegenerative Disease. J Neuroophthalmol 2017; 37 Suppl 1:S4-S13. [DOI: 10.1097/wno.0000000000000549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
27
|
Abstract
The kidney requires a large number of mitochondria to remove waste from the blood and regulate fluid and electrolyte balance. Mitochondria provide the energy to drive these important functions and can adapt to different metabolic conditions through a number of signalling pathways (for example, mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) pathways) that activate the transcriptional co-activator peroxisome proliferator-activated receptor-γ co-activator 1α (PGC1α), and by balancing mitochondrial dynamics and energetics to maintain mitochondrial homeostasis. Mitochondrial dysfunction leads to a decrease in ATP production, alterations in cellular functions and structure, and the loss of renal function. Persistent mitochondrial dysfunction has a role in the early stages and progression of renal diseases, such as acute kidney injury (AKI) and diabetic nephropathy, as it disrupts mitochondrial homeostasis and thus normal kidney function. Improving mitochondrial homeostasis and function has the potential to restore renal function, and administering compounds that stimulate mitochondrial biogenesis can restore mitochondrial and renal function in mouse models of AKI and diabetes mellitus. Furthermore, inhibiting the fission protein dynamin 1-like protein (DRP1) might ameliorate ischaemic renal injury by blocking mitochondrial fission.
Collapse
|
28
|
Assessment of the retinal posterior pole in dominant optic atrophy by spectral-domain optical coherence tomography and microperimetry. PLoS One 2017; 12:e0174560. [PMID: 28358911 PMCID: PMC5373574 DOI: 10.1371/journal.pone.0174560] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/11/2017] [Indexed: 11/24/2022] Open
Abstract
Background To assess posterior pole (PP) retinal structure in patients with genetically confirmed autosomal dominant optic atrophy (ADOA) using new spectral domain optical coherence tomography (SD-OCT) segmentation technology. To analyze retinal PP thickness in relation to retinal sensitivity data from microperimetry (MP) in ADOA patients. Methods and findings This prospective cross-sectional study included 11 patients with ADOA and 11 age-matched healthy subjects. All participants underwent both a “Posterior Pole” and “peripapillary RNFL (pRNFL)” scanning protocol using SD-OCT. Functional mapping of the PP was also performed using MP. A customized program was implemented in order to achieve accurate superimposition of MP sensitivity map onto SD-OCT map. The thickness of the PP different retinal layers and pRNFL was obtained and measured for each eye. Mean retinal sensitivity values and fixation stability were obtained and compared between ADOA patients and healthy subjects. Correlation analysis was performed on a point-to-point basis to evaluate the association between mean thickness and retinal sensitivity of each retinal layer. Total retinal thickness (TRT), Retinal Nerve Fiber Layer (RNFL), Ganglion Cell Layer (GCL), Inner Plexiform Layer (IPL), Inner Nuclear Layer (INL) and Inner Retinal Layers (IRL) at the posterior pole as well as pRNFL were significantly thinner in ADOA patients (P < 0.0001). On the contrary, the Outer Plexiform Layer (OPL) and the Outer Nuclear Layer (ONL) were significantly thicker in the ADOA group (P < 0.001). No significant differences were found in Retinal Pigment Epithelium (RPE) and Outer Retinal Layers (ORL) thickness between ADOA and controls. The average PP retinal sensitivity was significantly reduced in ADOA patients compared with controls (P < 0.001), as measured by microperimeter Nidek MP-1 (MP1). Fixation stability was significantly worse in the ADOA group (P = 0.01). The most severe sensitivity defects in ADOA patients were found at the level of the papillo-macular bundle (PMB). Conclusions Inner retinal layers showed pathological changes in ADOA patients. In addition, the whole retinal PP (not only the PMB) was significantly altered in ADOA, both in terms of retinal thickness and sensitivity.
Collapse
|
29
|
Characterization of two novel intronic OPA1 mutations resulting in aberrant pre-mRNA splicing. BMC MEDICAL GENETICS 2017; 18:22. [PMID: 28245802 PMCID: PMC5331656 DOI: 10.1186/s12881-017-0383-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/17/2017] [Indexed: 12/24/2022]
Abstract
BACKGROUND We report two novel splice region mutations in OPA1 in two unrelated families presenting with autosomal-dominant optic atrophy type 1 (ADOA1) (ADOA or Kjer type optic atrophy). Mutations in OPA1 encoding a mitochondrial inner membrane protein are a major cause of ADOA. METHODS We analyzed two unrelated families including four affected individuals clinically suspicious of ADOA. Standard ocular examinations were performed in affected individuals of both families. All coding exons, as well as exon-intron boundaries of the OPA1 gene were sequenced. In addition, multiplex ligation-dependent probe amplification (MLPA) was performed to uncover copy number variations in OPA1. mRNA processing was monitored using RT-PCR and subsequent cDNA analysis. RESULTS We report two novel splice region mutations in OPA1 in two unrelated individuals and their affected relatives, which were previously not described in the literature. In one family the heterozygous insertion and deletion c.[611-37_611-38insACTGGAGAATGTAAAGGGCTTT;611-6_611-16delCATATTTATCT] was found in all investigated family members leading to the activation of an intronic cryptic splice site. In the second family sequencing of OPA1 disclosed a de novo heterozygous deletion c.2012+4_2012+7delAGTA resulting in exon 18 and 19 skipping, which was not detected in healthy family members. CONCLUSION We identified two novel intronic mutations in OPA1 affecting the correct OPA1 pre-mRNA splicing, which was confirmed by OPA1 cDNA analysis. This study shows the importance of transcript analysis to determine the consequences of unclear intronic mutations in OPA1 in proximity to the intron-exon boundaries.
Collapse
|
30
|
Yu-Wai-Man P, Spyropoulos A, Duncan HJ, Guadagno JV, Chinnery PF. A multiple sclerosis-like disorder in patients with OPA1 mutations. Ann Clin Transl Neurol 2016; 3:723-9. [PMID: 27656661 PMCID: PMC5018584 DOI: 10.1002/acn3.323] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 03/23/2016] [Accepted: 04/10/2016] [Indexed: 12/12/2022] Open
Abstract
We describe three unrelated patients presenting with a spinal cord syndrome and neuroimaging features consistent with multiple sclerosis (MS). All harbored a pathogenic OPA1 mutation. Although the neurological phenotype resembled neuromyelitis optica (NMO), anti‐aquaporin 4 antibodies were not detected and the disorder followed a slow progressive course. The coincidental occurrence of OPA1 mutations and an MS‐like disorder is likely to have modulated the phenotypic manifestations of both disorders, but unlike the previously reported association of Leber hereditary optic neuropathy and MS (Harding disease), the optic neuropathy in patients with OPA1 mutations and an MS‐like disorder can be mild with a good visual prognosis.
Collapse
Affiliation(s)
- Patrick Yu-Wai-Man
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine Newcastle University Newcastle upon Tyne NE1 3BZ United Kingdom; Newcastle Eye Centre Royal Victoria Infirmary Newcastle upon Tyne NE1 3BZ United Kingdom; NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology London EC1V 2PD United Kingdom
| | - Achillefs Spyropoulos
- Department of Neurology Royal Victoria Infirmary Newcastle upon Tyne NE1 4LP United Kingdom
| | - Holly J Duncan
- Newcastle Eye Centre Royal Victoria Infirmary Newcastle upon Tyne NE1 3BZ United Kingdom
| | - Joseph V Guadagno
- Department of Neurology Royal Victoria Infirmary Newcastle upon Tyne NE1 4LP United Kingdom
| | - Patrick F Chinnery
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine Newcastle University Newcastle upon Tyne NE1 3BZ United Kingdom; MRC-Mitochondrial Biology Unit Cambridge Biomedical Campus Cambridge CB2 0XY United Kingdom; Department of Clinical Neurosciences Cambridge Biomedical Campus University of Cambridge Cambridge CB2 0QQ United Kingdom
| |
Collapse
|
31
|
Mishra P, Chan DC. Metabolic regulation of mitochondrial dynamics. J Cell Biol 2016; 212:379-87. [PMID: 26858267 PMCID: PMC4754720 DOI: 10.1083/jcb.201511036] [Citation(s) in RCA: 751] [Impact Index Per Article: 93.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/06/2016] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are renowned for their central bioenergetic role in eukaryotic cells, where they act as powerhouses to generate adenosine triphosphate from oxidation of nutrients. At the same time, these organelles are highly dynamic and undergo fusion, fission, transport, and degradation. Each of these dynamic processes is critical for maintaining a healthy mitochondrial population. Given the central metabolic function of mitochondria, it is not surprising that mitochondrial dynamics and bioenergetics reciprocally influence each other. We review the dynamic properties of mitochondria, with an emphasis on how these processes respond to cellular signaling events and how they affect metabolism.
Collapse
Affiliation(s)
- Prashant Mishra
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - David C Chan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| |
Collapse
|
32
|
Mutations in SLC25A46, encoding a UGO1-like protein, cause an optic atrophy spectrum disorder. Nat Genet 2015; 47:926-32. [PMID: 26168012 PMCID: PMC4520737 DOI: 10.1038/ng.3354] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 06/18/2015] [Indexed: 01/11/2023]
Abstract
Dominant optic atrophy (DOA)1,2 and axonal peripheral neuropathy (Charcot-Marie-Tooth Type 2 or CMT2)3 are hereditary neurodegenerative disorders most commonly caused by mutations in the canonical mitochondrial fusion genes OPA1 and MFN2, respectively4. In yeast, homologs of OPA1(Mgm1) and MFN2(Fzo1) work in concert with Ugo15,6, which has no human equivalent to date7. By whole exome sequencing patients with optic atrophy and CMT2, we identified four families with recessive mutations in SLC25A46. We demonstrate that SLC25A46, like Ugo1, is a modified carrier protein that has been recruited to the outer mitochondrial membrane and interacts with the inner membrane remodeling protein, mitofilin(Fcj1). Loss-of-function in cultured cells and in zebrafish unexpectedly leads to increased mitochondrial connectivity, while severely affecting the development and maintenance of neurons in the fish. The discovery of SLC25A46 strengthens the genetic overlap between optic atrophy and CMT2, while exemplifying a novel class of modified solute transporters linked to mitochondrial dynamics.
Collapse
|
33
|
Formichi P, Radi E, Giorgi E, Gallus GN, Brunetti J, Battisti C, Rufa A, Dotti MT, Franceschini R, Bracci L, Federico A. Analysis of opa1 isoforms expression and apoptosis regulation in autosomal dominant optic atrophy (ADOA) patients with mutations in the opa1 gene. J Neurol Sci 2015; 351:99-108. [DOI: 10.1016/j.jns.2015.02.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 11/29/2022]
|
34
|
Agarwal N, Hanumunthadu D, Afrasiabi M, Malaguarnera G, Cordeiro MF. Clinical update in optic nerve disorders. EXPERT REVIEW OF OPHTHALMOLOGY 2015. [DOI: 10.1586/17469899.2015.1003544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
35
|
Ramkumar HL, Savino PJ. A novel mutation in a case of dominant optic atrophy? Indian J Ophthalmol 2014; 62:1034-6. [PMID: 25449945 PMCID: PMC4278120 DOI: 10.4103/0301-4738.146043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A 39-year-old healthy woman presented for decreased vision at distance and near for 4 years. She also noted a decrease in her color vision. Her best-corrected visual acuities were 20/70 in each eye. Her visual fields were abnormal, and she had bilateral sluggish pupils, impaired color vision, and optic disc pallor. The magnetic resonance imaging of the brain, heavy metal screen, autoimmune work-up, B12, B6, folate, erythrocyte sedimentation rate, rapid plasma reagin, and Lyme titer were all normal. Optical coherence tomography of the macula and electroretinogram were normal; the visual evoked potential was unrecordable in both eyes. She denied a family history of similar ocular issues, and genotyping of the OPA1 gene revealed a novel previously unreported mutation at IVS12+10T >C.
Collapse
Affiliation(s)
| | - Peter J Savino
- Department of Ophthalmology, Shiley Eye Center, University of California-San Diego, La Jolla, CA, USA
| |
Collapse
|
36
|
Ferré M, Caignard A, Milea D, Leruez S, Cassereau J, Chevrollier A, Amati-Bonneau P, Verny C, Bonneau D, Procaccio V, Reynier P. Improved Locus-Specific Database forOPA1Mutations Allows Inclusion of Advanced Clinical Data. Hum Mutat 2014; 36:20-5. [DOI: 10.1002/humu.22703] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/12/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Marc Ferré
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Angélique Caignard
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Ophthalmology; University Hospital; Angers France
| | - Dan Milea
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Ophthalmology; University Hospital; Angers France
- Singapore National Eye Centre, Singapore Eye Research Institute; Duke-NUS Singapore
| | - Stéphanie Leruez
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Ophthalmology; University Hospital; Angers France
| | - Julien Cassereau
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Neurology; University Hospital; Angers France
| | | | - Patrizia Amati-Bonneau
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Christophe Verny
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Neurology; University Hospital; Angers France
| | - Dominique Bonneau
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Vincent Procaccio
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| | - Pascal Reynier
- CNRS 6214/INSERM 1083; Angers University; Angers France
- Department of Biochemistry and Genetics; University Hospital; Angers France
| |
Collapse
|
37
|
Rönnbäck C, Grønskov K, Larsen M. Retinal vessel diameters decrease with macular ganglion cell layer thickness in autosomal dominant optic atrophy and in healthy subjects. Acta Ophthalmol 2014; 92:670-4. [PMID: 24612963 DOI: 10.1111/aos.12378] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 01/29/2014] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate retinal trunk vessel diameters in subjects with autosomal dominant optic atrophy (ADOA) and mutation-free healthy relatives. METHODS This cross-sectional study included 52 ADOA patients with the optic atrophy 1 (OPA1) exon 28 (c.2826_2836delinsGGATGCTCCA) mutation (age 8.6-83.5 years) (best-corrected visual acuity (BCVA) 8-94 Early Treatment Diabetic Retinopathy Study (ETDRS) letters) and 55 mutation-free first-degree healthy relatives (age 8.9-68.7 years, BCVA 80-99). Analysis of fundus photographs provided integrated magnification-corrected measures of retinal vessel diameters (central retinal artery equivalent, CRAE, and central retinal vein equivalent, CRVE). Statistical analysis was corrected for age, gender, spherical equivalent refraction, axial length and mean arterial blood pressure (MABP) in a mixed model analysis. RESULTS Retinal arteries and veins were thinner in ADOA than in healthy controls (CRAE (mean ± 2 standard deviations (SD)) 153.9 ± 41.0 μm and CRVE 236.1 ± 42.0 μm in ADOA, CRAE 172.5 ± 25.0 μm (p = 0.0004) and CRVE 254.2 ± 37.6 μm (p = 0.0019) in healthy controls). MABP was comparable in the two groups (p = 0.18), and in both groups, CRAE decreased with increasing MABP (p = 0.01 and p < 0.0001, respectively). In ADOA, CRAE and CRVE decreased with age (p = 0.011 and p = 0.020, respectively) and CRAE decreased with decreasing BCVA (p = 0.011). In patients with ADOA and in healthy controls, CRAE decreased with decreasing average macular ganglion cell-inner plexiform layer (GC-IPL) thickness (p = 0.0017 and p = 0.0057, respectively). CONCLUSION Narrow retinal arteries and veins were associated not only with the severity of ADOA but with ganglion cell volume in patients with ADOA and in healthy subjects. This suggests that narrow vessels are a consequence rather than the cause of inner retinal hypoplasia or atrophy, although longitudinal studies are needed to confirm this hypothesis.
Collapse
Affiliation(s)
- Cecilia Rönnbäck
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
| | - Karen Grønskov
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- Applied Human Molecular Genetics; Kennedy Center; Rigshospitalet; Copenhagen Denmark
| | - Michael Larsen
- Department of Ophthalmology; Glostrup Hospital; Glostrup Denmark
- Faculty of Health Sciences; University of Copenhagen; Copenhagen Denmark
- National Eye Clinic; Kennedy Center; Rigshospitalet; Copenhagen Denmark
| |
Collapse
|
38
|
Abstract
SIGNIFICANCE Mitochondrial dynamics describes the continuous change in the position, size, and shape of mitochondria within cells. The morphological and functional complexity of neurons, the remarkable length of their processes, and the rapid changes in metabolic requirements arising from their intrinsic excitability render these cells particularly dependent on effective mitochondrial function and positioning. The rules that govern these changes and their functional significance are not fully understood, yet the dysfunction of mitochondrial dynamics has been implicated as a pathogenetic factor in a number of diseases, including disorders of the central and peripheral nervous systems. RECENT ADVANCES In recent years, a number of mutations of genes encoding proteins that play important roles in mitochondrial dynamics and function have been discovered in patients with Charcot-Marie-Tooth (CMT) disease, a hereditary peripheral neuropathy. These findings have directly linked mitochondrial pathology to the pathology of peripheral nerve and have identified certain aspects of mitochondrial dynamics as potential early events in the pathogenesis of CMT. In addition, mitochondrial dysfunction has now been implicated in the pathogenesis of noninherited neuropathies, including diabetic and inflammatory neuropathies. CRITICAL ISSUES The role of mitochondria in peripheral nerve diseases has been mostly examined in vitro, and less so in animal models. FUTURE DIRECTIONS This review examines available evidence for the role of mitochondrial dynamics in the pathogenesis of peripheral neuropathies, their relevance in human diseases, and future challenges for research in this field.
Collapse
Affiliation(s)
- Marija Sajic
- Department of Neuroinflammation, UCL Institute of Neurology , Queen Square, London, United Kingdom
| |
Collapse
|
39
|
Chan EYL, McQuibban GA. The mitochondrial rhomboid protease: its rise from obscurity to the pinnacle of disease-relevant genes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2916-25. [PMID: 24099009 DOI: 10.1016/j.bbamem.2013.05.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 05/08/2013] [Accepted: 05/10/2013] [Indexed: 12/15/2022]
Abstract
The Rhomboid proteases belong to a highly conserved family of proteins that are present in all branches of life. In Drosophila, the secretory pathway-localized rhomboid proteases are crucial for epidermal growth factor (EGF) signaling. The identification of a mitochondrial-localized rhomboid protease shed light on other functions of rhomboid proteases including the maintenance of mitochondrial morphology and the regulation of apoptosis. More recent work has revealed other functions of the mitochondrial rhomboid protease in mitochondrial and cellular biology, failure of which have been implicated in human diseases. In this review, we will summarize the current knowledge and disease relevance of the mitochondrial-localized rhomboid protease. This article is part of a Special Issue entitled: Intramembrane Proteases.
Collapse
Affiliation(s)
- Eliana Y L Chan
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
| | | |
Collapse
|
40
|
High-resolution en face images of microcystic macular edema in patients with autosomal dominant optic atrophy. BIOMED RESEARCH INTERNATIONAL 2013; 2013:676803. [PMID: 24369534 PMCID: PMC3863472 DOI: 10.1155/2013/676803] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 10/21/2013] [Accepted: 11/04/2013] [Indexed: 11/24/2022]
Abstract
The purpose of this study was to investigate the characteristics of microcystic macular edema (MME) determined from the en face images obtained by an adaptive optics (AO) fundus camera in patients with autosomal dominant optic atrophy (ADOA) and to try to determine the mechanisms underlying the degeneration of the inner retinal cells and RNFL by using the advantage of AO. Six patients from 4 families with ADOA underwent detailed ophthalmic examinations including spectral domain optical coherence tomography (SD-OCT). Mutational screening of all coding and flanking intron sequences of the OPA1 gene was performed by DNA sequencing. SD-OCT showed a severe reduction in the retinal nerve fiber layer (RNFL) thickness in all patients. A new splicing defect and two new frameshift mutations with premature termination of the Opa1 protein were identified in three families. A reported nonsense mutation was identified in one family. SD-OCT of one patient showed MME in the inner nuclear layer (INL) of the retina. AO images showed microcysts in the en face images of the INL. Our data indicate that AO is a useful method to identify MME in neurodegenerative diseases and may also help determine the mechanisms underlying the degeneration of the inner retinal cells and RNFL.
Collapse
|
41
|
Zhang B, Davidson MM, Zhou H, Wang C, Walker WF, Hei TK. Cytoplasmic irradiation results in mitochondrial dysfunction and DRP1-dependent mitochondrial fission. Cancer Res 2013; 73:6700-10. [PMID: 24080278 PMCID: PMC3934017 DOI: 10.1158/0008-5472.can-13-1411] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Direct DNA damage is often considered the primary cause of cancer in patients exposed to ionizing radiation or environmental carcinogens. Although mitochondria are known to play an important role in radiation-induced cellular response, the mechanisms by which cytoplasmic stimuli modulate mitochondrial dynamics and functions are largely unknown. In the present study, we examined changes in mitochondrial dynamics and functions triggered by α particle damage to the mitochondria in human small airway epithelial cells, using a precision microbeam irradiator with a beam width of 1 μm. Targeted cytoplasmic irradiation using this device resulted in mitochondrial fragmentation and a reduction of cytochrome c oxidase and succinate dehydrogenase activity, when compared with nonirradiated controls, suggesting a reduction in respiratory chain function. In addition, mitochondrial fragmentation or fission was associated with increased expression of the dynamin-like protein DRP1, which promotes mitochondrial fission. DRP1 inhibition by the drug mdivi-1 prevented radiation-induced mitochondrial fission, but respiratory chain function in mitochondria inhibited by radiation persisted for 12 hours. Irradiated cells also showed an increase in mitochondria-derived superoxide that could be quenched by dimethyl sulfoxide. Taken together, our results provide a mechanistic explanation for the extranuclear, nontargeted effects of ionizing radiation.
Collapse
Affiliation(s)
- Bo Zhang
- Center for Radiological Research, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, VC 11-205/218, New York, N.Y. 10032
| | - Mercy M. Davidson
- Department of Radiation Oncology, Columbia University, 630 West 168th Street, P&S 11-451, New York, N.Y. 10032
| | - Hongning Zhou
- Center for Radiological Research, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, VC 11-205/218, New York, N.Y. 10032
| | - Chunxin Wang
- Biochemistry Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Winsome F. Walker
- Department of Radiation Oncology, Columbia University, 630 West 168th Street, P&S 11-451, New York, N.Y. 10032
| | - Tom K. Hei
- Center for Radiological Research, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, VC 11-205/218, New York, N.Y. 10032
| |
Collapse
|
42
|
Liskova P, Ulmanova O, Tesina P, Melsova H, Diblik P, Hansikova H, Tesarova M, Votruba M. Novel OPA1 missense mutation in a family with optic atrophy and severe widespread neurological disorder. Acta Ophthalmol 2013; 91:e225-31. [PMID: 23387428 DOI: 10.1111/aos.12038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To identify the underlying molecular genetic cause in a Czech family with optic atrophy, deafness, ptosis, ophthalmoplegia, polyneuropathy and ataxia transmitted as an autosomal dominant trait. METHODS Ophthalmological and neurological examination followed by molecular genetic analyses. RESULTS Seven family members were clinically affected. There was a variable but progressive visual, hearing and neurological disability across the family as a whole. The majority of subjects presented with impairment of visual function and a variable degree of ptosis and/or ophthalmoplegia from the first to the third decade of life. Deafness, neuropathy and ataxia appeared later, in the third and fourth decade. Migraine, tachycardia, intention tremor, nystagmus and cervical dystonia were observed in isolated individuals. A significant overall feature was the high level of neurological disability leading to 3 of 4 members being unable to walk or stand unaided before the age of 60 years. A novel missense mutation c.1345A>C (p.Thr449Pro) in OPA1 segregating with the disease phenotype over three generations was detected. In silico analysis supported pathogenicity of the identified sequence variant. CONCLUSION Our work expands the spectrum of mutation in OPA1, which may lead to severe multisystem neurological disorder. The molecular genetic cause of dominant optic atrophy in the Czech population is reported for the first time. We propose that regular cardiac follow-up in patients diagnosed with dominant optic atrophy and widespread neurological disease should be considered.
Collapse
Affiliation(s)
- Petra Liskova
- Laboratory of the Biology and Pathology of the Eye, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague, Czech Republic
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Mitochondrial biogenesis and dynamics in neurodegeneration: a causative relationship. Neurochem Res 2013; 39:542-5. [PMID: 23397288 DOI: 10.1007/s11064-013-0997-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/30/2013] [Accepted: 02/01/2013] [Indexed: 01/29/2023]
|
44
|
Masson-Le Guen É, Cochard-Marianowski C, Macarez R, Charlin JF, Cochener B. Bilans neuro-ophtalmologiques dans le service d’ophtalmologie du CHU de Brest : étude rétrospective sur 269 patients (janvier 2004–octobre 2009). J Fr Ophtalmol 2012; 35:768-75. [DOI: 10.1016/j.jfo.2011.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 08/03/2011] [Accepted: 08/08/2011] [Indexed: 10/27/2022]
|
45
|
Abstract
Mitochondria are dynamic organelles that continually undergo fusion and fission. These opposing processes work in concert to maintain the shape, size, and number of mitochondria and their physiological function. Some of the major molecules mediating mitochondrial fusion and fission in mammals have been discovered, but the underlying molecular mechanisms are only partially unraveled. In particular, the cast of characters involved in mitochondrial fission needs to be clarified. By enabling content mixing between mitochondria, fusion and fission serve to maintain a homogeneous and healthy mitochondrial population. Mitochondrial dynamics has been linked to multiple mitochondrial functions, including mitochondrial DNA stability, respiratory capacity, apoptosis, response to cellular stress, and mitophagy. Because of these important functions, mitochondrial fusion and fission are essential in mammals, and even mild defects in mitochondrial dynamics are associated with disease. A better understanding of these processes likely will ultimately lead to improvements in human health.
Collapse
Affiliation(s)
- David C Chan
- Division of Biology and the Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125, USA.
| |
Collapse
|
46
|
Lee S, Sterky FH, Mourier A, Terzioglu M, Cullheim S, Olson L, Larsson NG. Mitofusin 2 is necessary for striatal axonal projections of midbrain dopamine neurons. Hum Mol Genet 2012; 21:4827-35. [PMID: 22914740 DOI: 10.1093/hmg/dds352] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mitochondrial dysfunction is implicated in aging and degenerative disorders such as Parkinson's disease (PD). Continuous fission and fusion of mitochondria shapes their morphology and is essential to maintain oxidative phosphorylation. Loss-of-function mutations in PTEN-induced kinase1 (PINK1) or Parkin cause a recessive form of PD and have been linked to altered regulation of mitochondrial dynamics. More specifically, the E3 ubiquitin ligase Parkin has been shown to directly regulate the levels of mitofusin 1 (Mfn1) and Mfn2, two homologous outer membrane large GTPases that govern mitochondrial fusion, but it is not known whether this is of relevance for disease pathophysiology. Here, we address the importance of Mfn1 and Mfn2 in midbrain dopamine (DA) neurons in vivo by characterizing mice with DA neuron-specific knockout of Mfn1 or Mfn2. We find that Mfn1 is dispensable for DA neuron survival and motor function. In contrast, Mfn2 DA neuron-specific knockouts develop a fatal phenotype with reduced weight, locomotor disturbances and death by 7 weeks of age. Mfn2 knockout DA neurons have spherical and enlarged mitochondria with abnormal cristae and impaired respiratory chain function. Parkin does not translocate to these defective mitochondria. Surprisingly, Mfn2 DA neuron-specific knockout mice have normal numbers of midbrain DA neurons, whereas there is a severe loss of DA nerve terminals in the striatum, accompanied by depletion of striatal DA levels. These results show that Mfn2, but not Mfn1, is required for axonal projections of DA neurons in vivo.
Collapse
Affiliation(s)
- Seungmin Lee
- Department of Laboratory Medicine, and 2Department of Neuroscience, Karolinska Institutet, Retzius väg 8, Stockholm, Sweden
| | | | | | | | | | | | | |
Collapse
|
47
|
Lenaers G, Hamel C, Delettre C, Amati-Bonneau P, Procaccio V, Bonneau D, Reynier P, Milea D. Dominant optic atrophy. Orphanet J Rare Dis 2012; 7:46. [PMID: 22776096 PMCID: PMC3526509 DOI: 10.1186/1750-1172-7-46] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 03/15/2012] [Indexed: 11/18/2022] Open
Abstract
Definition of the disease Dominant Optic Atrophy (DOA) is a neuro-ophthalmic condition characterized by a bilateral degeneration of the optic nerves, causing insidious visual loss, typically starting during the first decade of life. The disease affects primary the retinal ganglion cells (RGC) and their axons forming the optic nerve, which transfer the visual information from the photoreceptors to the lateral geniculus in the brain. Epidemiology The prevalence of the disease varies from 1/10000 in Denmark due to a founder effect, to 1/30000 in the rest of the world. Clinical description DOA patients usually suffer of moderate visual loss, associated with central or paracentral visual field deficits and color vision defects. The severity of the disease is highly variable, the visual acuity ranging from normal to legal blindness. The ophthalmic examination discloses on fundoscopy isolated optic disc pallor or atrophy, related to the RGC death. About 20% of DOA patients harbour extraocular multi-systemic features, including neurosensory hearing loss, or less commonly chronic progressive external ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like illness, spastic paraplegia or cataracts. Aetiology Two genes (OPA1, OPA3) encoding inner mitochondrial membrane proteins and three loci (OPA4, OPA5, OPA8) are currently known for DOA. Additional loci and genes (OPA2, OPA6 and OPA7) are responsible for X-linked or recessive optic atrophy. All OPA genes yet identified encode mitochondrial proteins embedded in the inner membrane and ubiquitously expressed, as are the proteins mutated in the Leber Hereditary Optic Neuropathy. OPA1 mutations affect mitochondrial fusion, energy metabolism, control of apoptosis, calcium clearance and maintenance of mitochondrial genome integrity. OPA3 mutations only affect the energy metabolism and the control of apoptosis. Diagnosis Patients are usually diagnosed during their early childhood, because of bilateral, mild, otherwise unexplained visual loss related to optic discs pallor or atrophy, and typically occurring in the context of a family history of DOA. Optical Coherence Tomography further discloses non-specific thinning of retinal nerve fiber layer, but a normal morphology of the photoreceptors layers. Abnormal visual evoked potentials and pattern ERG may also reflect the dysfunction of the RGCs and their axons. Molecular diagnosis is provided by the identification of a mutation in the OPA1 gene (75% of DOA patients) or in the OPA3 gene (1% of patients). Prognosis Visual loss in DOA may progress during puberty until adulthood, with very slow subsequent chronic progression in most of the cases. On the opposite, in DOA patients with associated extra-ocular features, the visual loss may be more severe over time. Management To date, there is no preventative or curative treatment in DOA; severely visually impaired patients may benefit from low vision aids. Genetic counseling is commonly offered and patients are advised to avoid alcohol and tobacco consumption, as well as the use of medications that may interfere with mitochondrial metabolism. Gene and pharmacological therapies for DOA are currently under investigation.
Collapse
Affiliation(s)
- Guy Lenaers
- Institut des Neurosciences de Montpellier, U1051 de l'INSERM, Université de Montpellier I et II, BP 74103, F-34091 Montpellier cedex 05, France.
| | | | | | | | | | | | | | | |
Collapse
|
48
|
The Rhodadyns, a New Class of Small Molecule Inhibitors of Dynamin GTPase Activity. ACS Med Chem Lett 2012; 3:352-6. [PMID: 24900478 DOI: 10.1021/ml200284s] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 03/26/2012] [Indexed: 02/04/2023] Open
Abstract
Six focused rhodanine-based libraries, 60 compounds in total, were synthesized and evaluated as potential dynamin I GTPase inhibitors. Twenty-six were more potent than the lead compound with 13 returning IC50 values ≤10 μM, making the Rhodadyn series among the most active dynamin inhibitors reported. Two analogues were highly effective at blocking receptor-mediated endocytosis: C10 and D10 with IC50(RME) = 7.0 ± 2.2 and 5.9 ± 1.0 μM, respectively. These compounds are equipotent with the best reported in-cell dynamin inhibitors.
Collapse
|
49
|
Lax NZ, Turnbull DM, Reeve AK. Mitochondrial mutations: newly discovered players in neuronal degeneration. Neuroscientist 2012; 17:645-58. [PMID: 22130639 PMCID: PMC3757997 DOI: 10.1177/1073858411385469] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mutations in mitochondrial DNA cause a number of neurological diseases with defined neuropathology; however, mutations in this genome have also been found to be important in a number of more common neurodegenerative diseases. In this review, the authors discuss the importance of mitochondrial DNA mutations in a number of different diseases and speculate how such mutations could lead to cell loss. Increasing our understanding of how mitochondrial DNA mutations affect mitochondrial metabolism and subsequently result in neurodegenerative disease will prove vital to the development of targeted therapies and treatments.
Collapse
Affiliation(s)
- Nichola Z Lax
- Centre for Brain Ageing and Vitality, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | | |
Collapse
|
50
|
Zhang J, Yuan Y, Lin B, Feng H, Li Y, Dai X, Zhou H, Dong X, Liu XL, Guan MX. A novel OPA1 mutation in a Chinese family with autosomal dominant optic atrophy. Biochem Biophys Res Commun 2012; 419:670-5. [PMID: 22382025 DOI: 10.1016/j.bbrc.2012.02.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Accepted: 02/13/2012] [Indexed: 12/01/2022]
Abstract
A large four-generation Chinese family with autosomal dominant optic atrophy (ADOA) was investigated in the present study. Eight of the family members were affected in this pedigree. The affected family members exhibited early-onset and progressive visual impairment, resulting in mild to profound loss of visual acuity. The average age-at-onset was 15.9years. A new heterozygous mutation c.C1198G was identified by sequence analysis of the 12th exon of the OPA1 gene. This mutation resulted in a proline to alanine substitution at codon 400, which was located in an evolutionarily conserved region. This missense mutation in the GTPase domain was supposed to result in a loss of function for the encoded protein and act through a dominant negative effect. No other mutations associated with optic atrophy were found in our present study. The c.C1198G heterozygous mutation in the OPA1 gene may be a novel key pathogenic mutation in this pedigree with ADOA. Furthermore, additional nuclear modifier genes, environmental factors, and psychological factors may also contribute to the phenotypic variability of ADOA in this pedigree.
Collapse
Affiliation(s)
- Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|