1
|
Nitta Y, Osaka J, Maki R, Hakeda-Suzuki S, Suzuki E, Ueki S, Suzuki T, Sugie A. Drosophila model to clarify the pathological significance of OPA1 in autosomal dominant optic atrophy. eLife 2024; 12:RP87880. [PMID: 39177028 PMCID: PMC11343565 DOI: 10.7554/elife.87880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2024] Open
Abstract
Autosomal dominant optic atrophy (DOA) is a progressive form of blindness caused by degeneration of retinal ganglion cells and their axons, mainly caused by mutations in the OPA1 mitochondrial dynamin like GTPase (OPA1) gene. OPA1 encodes a dynamin-like GTPase present in the mitochondrial inner membrane. When associated with OPA1 mutations, DOA can present not only ocular symptoms but also multi-organ symptoms (DOA plus). DOA plus often results from point mutations in the GTPase domain, which are assumed to have dominant-negative effects. However, the presence of mutations in the GTPase domain does not always result in DOA plus. Therefore, an experimental system to distinguish between DOA and DOA plus is needed. In this study, we found that loss-of-function mutations of the dOPA1 gene in Drosophila can imitate the pathology of optic nerve degeneration observed in DOA. We successfully rescued this degeneration by expressing the human OPA1 (hOPA1) gene, indicating that hOPA1 is functionally interchangeable with dOPA1 in the fly system. However, mutations previously identified did not ameliorate the dOPA1 deficiency phenotype. By expressing both WT and DOA plus mutant hOPA1 forms in the optic nerve of dOPA1 mutants, we observed that DOA plus mutations suppressed the rescue, facilitating the distinction between loss-of-function and dominant-negative mutations in hOPA1. This fly model aids in distinguishing DOA from DOA plus and guides initial hOPA1 mutation treatment strategies.
Collapse
Affiliation(s)
- Yohei Nitta
- Brain Research Institute, Niigata UniversityNiigataJapan
| | - Jiro Osaka
- Brain Research Institute, Niigata UniversityNiigataJapan
- School of Life Science and Technology, Tokyo Institute of TechnologyYokohamaJapan
| | - Ryuto Maki
- School of Life Science and Technology, Tokyo Institute of TechnologyYokohamaJapan
| | - Satoko Hakeda-Suzuki
- School of Life Science and Technology, Tokyo Institute of TechnologyYokohamaJapan
- Research Initiatives and Promotion Organization, Yokohama National UniversityYokohamaJapan
| | - Emiko Suzuki
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan UniversityHachiojiJapan
- Department of Gene Function and Phenomics, National Institute of GeneticsMishimaJapan
| | - Satoshi Ueki
- Division of Ophthalmology and Visual Science, Graduate School of Medical and Dental Sciences, Niigata UniversityNiigataJapan
| | - Takashi Suzuki
- School of Life Science and Technology, Tokyo Institute of TechnologyYokohamaJapan
| | - Atsushi Sugie
- Brain Research Institute, Niigata UniversityNiigataJapan
| |
Collapse
|
2
|
Liu YF, Luo XY, Zhao ZC, Zheng W, Lv HY, Luo WM. Association between optic atrophy 1 polymorphisms and primary open angle glaucoma risk: Based on a meta-analysis. Eur J Ophthalmol 2024; 34:708-718. [PMID: 37872653 DOI: 10.1177/11206721231208244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
BACKGROUND Emerging evidence suggested a significant association between optic atrophy 1 (OPA1) polymorphisms and primary open angle glaucoma (POAG) risk. However, the current data are inconsistent or even contradictory. Given these, we conducted a meta-analysis to examine the precise association between OPA1 polymorphisms and POAG risk. MATERIALS AND METHODS Online databases were retrieved, and the related studies were reviewed from inception to December 1, 2022. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to examine the statistical power of each genetic model. In addition, heterogeneity, sensitivity, cumulative analysis, and publication bias were analyzed to guarantee statistical power. RESULT Overall, 14 studies within 11 publications (involving 2,413 POAG patients and 1,904 controls) were included and some significant association between OPA1 rs166850 C/T (T vs. C: OR = 1.24, 95%CI = 1.06-1.45, P = 0.01, I2 = 39.0%; CT vs. CC: OR = 1.37, 95%CI = 1.05-1.79, P = 0.02, I2 = 41.6%; CT + TT vs. CC: 1.37, 95%CI = 1.06-1.77, P = 0.02, I2 = 41.6%), rs10451941T/C (TC + CC vs. TT: OR = 1.79, 95%CI = 1.41-2.28, P < 0.01, I2 = 71.9%) polymorphisms and POAG susceptibility. In addition, further significant associations were also observed in the stratified analysis, especially in normal tension glaucoma groups and Caucasian descendants. CONCLUSION The observed evidences suggest that OPA1 polymorphisms may be associate with POAG susceptibility significantly.
Collapse
Affiliation(s)
- Yue-Feng Liu
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Xiang-Yu Luo
- Department of Cardiothoracic Surgery, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Zhi-Cai Zhao
- Department of Pulmonary and Critical Care Medicine, Wudang Mountain Campus of Taihe Hospital Shiyan, Shiyan, Hubei, China
| | - Wu Zheng
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Hai-Yang Lv
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Wei-Min Luo
- Department of Cardiothoracic Surgery, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| |
Collapse
|
3
|
Pan L, Wu J, Wang N. Association of Gene Polymorphisms with Normal Tension Glaucoma: A Systematic Review and Meta-Analysis. Genes (Basel) 2024; 15:491. [PMID: 38674425 PMCID: PMC11050218 DOI: 10.3390/genes15040491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Normal tension glaucoma (NTG) is becoming a more and more serious problem, especially in Asia. But the pathological mechanisms are still not illustrated clearly. We carried out this research to uncover the gene polymorphisms with NTG. METHODS We searched in Web of Science, Embase, Pubmed and Cochrane databases for qualified case-control studies investigating the association between single nucleotide polymorphisms (SNPs) and NTG risk. Odds ratios (ORs) and 95% confidence intervals (CIs) for each SNP were estimated by fixed- or random-effect models. Sensitivity analysis was also performed to strengthen the reliability of the results. RESULTS Fifty-six studies involving 33 candidate SNPs in 14 genetic loci were verified to be eligible for our meta-analysis. Significant associations were found between 16 SNPs (rs166850 of OPA1; rs10451941 of OPA1; rs735860 of ELOVL5; rs678350 of HK2; c.603T>A/Met98Lys of OPTN; c.412G>A/Thr34Thr of OPTN; rs10759930 of TLR4; rs1927914 of TLR4; rs1927911 of TLR4; c.*70C>G of EDNRA; rs1042522/-Arg72Pro of P53; rs10483727 of SIX1-SIX6; rs33912345 of SIX1-SIX6; rs2033008 of NCK2; rs3213787 of SRBD1 and c.231G>A of EDNRA) with increased or decreased risk of NTG. CONCLUSIONS In this study, we confirmed 16 genetic polymorphisms in 10 genes (OPA1, ELOVL5, HK2, OPTN, TLR4, EDNRA, P53, NCK2, SRBD1 and SIX1-SIX6) were associated with NTG.
Collapse
Affiliation(s)
- Lijie Pan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, No. 1 Dong Jiao Min Xiang Street, Dongcheng District, Beijing 100730, China;
| | - Jian Wu
- School of Life Sciences, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871, China
- Henan Academy of Innovations in Medical Science, No. 2 Biotechnology Street, Hangkonggang District, Zhengzhou 450000, China
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, No. 1 Dong Jiao Min Xiang Street, Dongcheng District, Beijing 100730, China;
| |
Collapse
|
4
|
Rombaut A, Brautaset R, Williams PA, Tribble JR. Glial metabolic alterations during glaucoma pathogenesis. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1290465. [PMID: 38983068 PMCID: PMC11182098 DOI: 10.3389/fopht.2023.1290465] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/10/2023] [Indexed: 07/11/2024]
Abstract
Glaucoma is the leading cause of irreversible blindness. Current treatment options are limited and often only slow disease progression. Metabolic dysfunction has recently been recognized as a key early and persistent mechanism in glaucoma pathophysiology. Several intrinsic metabolic dysfunctions have been identified and treated in retinal ganglion cells to provide neuroprotection. Growing pre-clinical and clinical evidence has confirmed that metabolic alterations in glaucoma are widespread, occurring across visual system tissues, in ocular fluids, in blood/serum, and at the level of genomic and mitochondrial DNA. This suggests that metabolic dysfunction is not constrained to retinal ganglion cells and that metabolic alterations extrinsic to retinal ganglion cells may contribute to their metabolic compromise. Retinal ganglion cells are reliant on glial metabolic support under normal physiological conditions, but the implications of metabolic dysfunction in glia are underexplored. We highlight emerging evidence that has demonstrated metabolic alterations occurring within glia in glaucoma, and how this may affect neuro-glial metabolic coupling and the metabolic vulnerability of retinal ganglion cells. In other neurodegenerative diseases which share features with glaucoma, several other glial metabolic alterations have been identified, suggesting that similar mechanisms and therapeutic targets may exist in glaucoma.
Collapse
Affiliation(s)
| | | | - Pete A. Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - James R. Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
5
|
Fox AR, Fingert JH. Familial normal tension glaucoma genetics. Prog Retin Eye Res 2023; 96:101191. [PMID: 37353142 DOI: 10.1016/j.preteyeres.2023.101191] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/25/2023]
Abstract
Glaucoma is defined by characteristic optic nerve damage and corresponding visual field defects and is the leading cause of irreversible blindness in the world. Elevated intraocular pressure (IOP) is a strong risk factor for developing glaucoma. However, glaucoma can occur at any IOP. Normal tension glaucoma (NTG) arises with IOPs that are within what has been defined as a normal range, i.e., 21 mm Hg or less, which may present challenges in its diagnosis and management. Identifying inheritance patterns and genetic mutations in families with NTG has helped elucidate mechanisms of NTG, however the pathophysiology is complex and not fully understood. Approximately 2% of NTG cases are caused primarily by mutations in single genes, optineurin (OPTN), TANK binding kinase 1 (TKB1), or myocilin (MYOC). Herein, we review pedigree studies of NTG and autosomal dominant NTG caused by OPTN, TBK1, and MYOC mutations. We review identified mutations and resulting clinical features of OPTN-associated and TBK1-associated NTG, including long-term follow up of these patients with NTG. In addition, we report a new four-generation pedigree of NTG caused by a Glu50Lys OPTN mutation, including six family members with a mean follow up of 17 years. Common features of OPTN -associated NTG due to Glu50Lys mutation included early onset of disease with an IOP <21 mm Hg, marked optic disc cupping, and progressive visual field loss which appeared to stabilize once an IOP of less than 10 mm Hg was achieved. Lastly, we review risk factor genes which have been identified to contribute to the complex inheritance of NTG.
Collapse
Affiliation(s)
- Austin R Fox
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | - John H Fingert
- Institute for Vision Research, University of Iowa, Iowa City, IA, USA; Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
| |
Collapse
|
6
|
Tribble JR, Hui F, Quintero H, El Hajji S, Bell K, Di Polo A, Williams PA. Neuroprotection in glaucoma: Mechanisms beyond intraocular pressure lowering. Mol Aspects Med 2023; 92:101193. [PMID: 37331129 DOI: 10.1016/j.mam.2023.101193] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/25/2023] [Accepted: 06/04/2023] [Indexed: 06/20/2023]
Abstract
Glaucoma is a common, complex, multifactorial neurodegenerative disease characterized by progressive dysfunction and then loss of retinal ganglion cells, the output neurons of the retina. Glaucoma is the most common cause of irreversible blindness and affects ∼80 million people worldwide with many more undiagnosed. The major risk factors for glaucoma are genetics, age, and elevated intraocular pressure. Current strategies only target intraocular pressure management and do not directly target the neurodegenerative processes occurring at the level of the retinal ganglion cell. Despite strategies to manage intraocular pressure, as many as 40% of glaucoma patients progress to blindness in at least one eye during their lifetime. As such, neuroprotective strategies that target the retinal ganglion cell and these neurodegenerative processes directly are of great therapeutic need. This review will cover the recent advances from basic biology to on-going clinical trials for neuroprotection in glaucoma covering degenerative mechanisms, metabolism, insulin signaling, mTOR, axon transport, apoptosis, autophagy, and neuroinflammation. With an increased understanding of both the basic and clinical mechanisms of the disease, we are closer than ever to a neuroprotective strategy for glaucoma.
Collapse
Affiliation(s)
- James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia; Department of Optometry & Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Heberto Quintero
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Sana El Hajji
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Katharina Bell
- NHMRC Clinical Trials Centre, University of Sydney, Australia; Eye ACP Duke-NUS, Singapore
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
7
|
Stavropoulos D, Grewal MK, Petriti B, Chau KY, Hammond CJ, Garway-Heath DF, Lascaratos G. The Role of Mitophagy in Glaucomatous Neurodegeneration. Cells 2023; 12:1969. [PMID: 37566048 PMCID: PMC10417839 DOI: 10.3390/cells12151969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/15/2023] [Accepted: 07/19/2023] [Indexed: 08/12/2023] Open
Abstract
This review aims to provide a better understanding of the emerging role of mitophagy in glaucomatous neurodegeneration, which is the primary cause of irreversible blindness worldwide. Increasing evidence from genetic and other experimental studies suggests that mitophagy-related genes are implicated in the pathogenesis of glaucoma in various populations. The association between polymorphisms in these genes and increased risk of glaucoma is presented. Reduction in intraocular pressure (IOP) is currently the only modifiable risk factor for glaucoma, while clinical trials highlight the inadequacy of IOP-lowering therapeutic approaches to prevent sight loss in many glaucoma patients. Mitochondrial dysfunction is thought to increase the susceptibility of retinal ganglion cells (RGCs) to other risk factors and is implicated in glaucomatous degeneration. Mitophagy holds a vital role in mitochondrial quality control processes, and the current review explores the mitophagy-related pathways which may be linked to glaucoma and their therapeutic potential.
Collapse
Affiliation(s)
- Dimitrios Stavropoulos
- Department of Ophthalmology, King’s College Hospital, London SE5 9RS, UK;
- Department of Ophthalmology, 417 Veterans Army Hospital (NIMTS), 11521 Athens, Greece
| | - Manjot K. Grewal
- NIHR Biomedical Research Center, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Division of Optometry and Visual Science, School of Health Sciences, City, University of London, London EC1V 0HB, UK
| | - Bledi Petriti
- NIHR Biomedical Research Center, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Department of Clinical & Movement Neurosciences, UCL Queens Square Institute of Neurology, London NW3 2PF, UK
| | - Kai-Yin Chau
- Department of Clinical & Movement Neurosciences, UCL Queens Square Institute of Neurology, London NW3 2PF, UK
| | - Christopher J. Hammond
- Section of Ophthalmology, School of Life Course Sciences, King’s College London, London SE1 7EH, UK
- Department of Ophthalmology, St Thomas’ Hospital, London SE1 7EH, UK
| | - David F. Garway-Heath
- NIHR Biomedical Research Center, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Gerassimos Lascaratos
- Department of Ophthalmology, King’s College Hospital, London SE5 9RS, UK;
- Section of Ophthalmology, School of Life Course Sciences, King’s College London, London SE1 7EH, UK
| |
Collapse
|
8
|
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: 36] [Impact Index Per Article: 36.0] [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
|
9
|
Al Ojaimi M, Salah A, El-Hattab AW. Mitochondrial Fission and Fusion: Molecular Mechanisms, Biological Functions, and Related Disorders. MEMBRANES 2022; 12:membranes12090893. [PMID: 36135912 PMCID: PMC9502208 DOI: 10.3390/membranes12090893] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/04/2022] [Accepted: 09/11/2022] [Indexed: 05/13/2023]
Abstract
Mitochondria are dynamic organelles that undergo fusion and fission. These active processes occur continuously and simultaneously and are mediated by nuclear-DNA-encoded proteins that act on mitochondrial membranes. The balance between fusion and fission determines the mitochondrial morphology and adapts it to the metabolic needs of the cells. Therefore, these two processes are crucial to optimize mitochondrial function and its bioenergetics abilities. Defects in mitochondrial proteins involved in fission and fusion due to pathogenic variants in the genes encoding them result in disruption of the equilibrium between fission and fusion, leading to a group of mitochondrial diseases termed disorders of mitochondrial dynamics. In this review, the molecular mechanisms and biological functions of mitochondrial fusion and fission are first discussed. Then, mitochondrial disorders caused by defects in fission and fusion are summarized, including disorders related to MFN2, MSTO1, OPA1, YME1L1, FBXL4, DNM1L, and MFF genes.
Collapse
Affiliation(s)
- Mode Al Ojaimi
- College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
- Pediatrics Department, University Hospital Sharjah, Sharjah 72772, United Arab Emirates
| | - Azza Salah
- Pediatrics Department, University Hospital Sharjah, Sharjah 72772, United Arab Emirates
| | - Ayman W. El-Hattab
- College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
- Pediatrics Department, University Hospital Sharjah, Sharjah 72772, United Arab Emirates
- Genetics and Metabolic Department, KidsHeart Medical Center, Abu Dhabi 505193, United Arab Emirates
- Correspondence: ; Tel.: +971-508875123
| |
Collapse
|
10
|
Amin D, Kuwajima T. Differential Retinal Ganglion Cell Vulnerability, A Critical Clue for the Identification of Neuroprotective Genes in Glaucoma. FRONTIERS IN OPHTHALMOLOGY 2022; 2:905352. [PMID: 38983528 PMCID: PMC11182220 DOI: 10.3389/fopht.2022.905352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 05/05/2022] [Indexed: 07/11/2024]
Abstract
Retinal ganglion cells (RGCs) are the neurons in the retina which directly project to the brain and transmit visual information along the optic nerve. Glaucoma, one of the leading causes of blindness, is characterized by elevated intraocular pressure (IOP) and degeneration of the optic nerve, which is followed by RGC death. Currently, there are no clinical therapeutic drugs or molecular interventions that prevent RGC death outside of IOP reduction. In order to overcome these major barriers, an increased number of studies have utilized the following combined analytical methods: well-established rodent models of glaucoma including optic nerve injury models and transcriptomic gene expression profiling, resulting in the successful identification of molecules and signaling pathways relevant to RGC protection. In this review, we present a comprehensive overview of pathological features in a variety of animal models of glaucoma and top differentially expressed genes (DEGs) depending on disease progression, RGC subtypes, retinal regions or animal species. By comparing top DEGs among those different transcriptome profiles, we discuss whether commonly listed DEGs could be defined as potential novel therapeutic targets in glaucoma, which will facilitate development of future therapeutic neuroprotective strategies for treatments of human patients in glaucoma.
Collapse
Affiliation(s)
- Dwarkesh Amin
- Department of Ophthalmology, The Louis J. Fox Center for Vision Restoration, The University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Takaaki Kuwajima
- Department of Ophthalmology, The Louis J. Fox Center for Vision Restoration, The University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| |
Collapse
|
11
|
Milanowski P, Kosior-Jarecka E, Łukasik U, Wróbel-Dudzińska D, Milanowska J, Khor CC, Aung T, Kocki J, Żarnowski T. Associations between OPA1, MFN1, and MFN2 polymorphisms and primary open angle glaucoma in Polish participants of European ancestry. Ophthalmic Genet 2021; 43:42-47. [PMID: 34425738 DOI: 10.1080/13816810.2021.1970197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Glaucomatous optic nerve damage is caused by selective death of retinal ganglion cells (RGCs). Another condition with underlying loss of RGCs is autosomal dominant optic atrophy (ADOA). Majority of ADOA patients have mutations in OPA1, gene responsible for mitochondrial fusion final steps. Clinical resemblance between the two diseases make genes involved in mitochondrial fusion good candidates as glaucoma genes. In this study, we investigated if selected polymorphisms of OPA1, MFN1, and MFN2 were associated with glaucoma in Polish population. METHODS Four OPA1 (rs166850, rs10451941, rs7624750, rs9851685), one MFN1 (rs2111534), and two MFN2 (rs873458, rs2295281) single nucleotide polymorphisms were investigated in 304 primary open angle glaucoma patients (204 with normal tension glaucoma, 100 with high-tension glaucoma) and 258 control subjects using RT-PCR method. RESULTS There was a significant difference in genotype frequencies of rs9851685 and rs2111534 polymorphisms between glaucoma patients and control subjects. Several genotype combinations comprising SNPs at OPA1 and MFN1 were significantly differently distributed in a three-way comparison between controls, patients with NTG and patients with HTG. None of the studied MFN2 polymorphisms was significantly associated with HTG or NTG. CONCLUSIONS In studied population, genotype CC and allele C of rs9851685 OPA1 polymorphism are NTG risk factors, whereas TT genotype and T allele of this polymorphism are protective factors against NTG. Genotype GA of rs2111534 MFN1 polymorphism is an HTG risk factor and AA genotype of this polymorphism is a protective factor against HTG. Several OPA1 and MFN2 genotype combinations are significantly associated with either increased or decreased risk of glaucoma in this population.
Collapse
Affiliation(s)
- Piotr Milanowski
- Department of Diagnostics and Microsurgery of Glaucoma, Medical University of Lublin, Lublin, Poland
| | - Ewa Kosior-Jarecka
- Department of Diagnostics and Microsurgery of Glaucoma, Medical University of Lublin, Lublin, Poland
| | - Urszula Łukasik
- Department of Diagnostics and Microsurgery of Glaucoma, Medical University of Lublin, Lublin, Poland
| | - Dominika Wróbel-Dudzińska
- Department of Diagnostics and Microsurgery of Glaucoma, Medical University of Lublin, Lublin, Poland
| | - Joanna Milanowska
- Department of Applied Psychology, Medical University of Lublin, Lublin, Poland
| | - Chiea Chuen Khor
- Laboratory of Complex Disease Genetics, Genome Institute of Singapore, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Center, Singapore
| | - Janusz Kocki
- Department of Clinical Genetics, Medical University of Lublin, Lublin, Poland
| | - Tomasz Żarnowski
- Department of Diagnostics and Microsurgery of Glaucoma, Medical University of Lublin, Lublin, Poland
| |
Collapse
|
12
|
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: 42] [Impact Index Per Article: 14.0] [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
|
13
|
Muench NA, Patel S, Maes ME, Donahue RJ, Ikeda A, Nickells RW. The Influence of Mitochondrial Dynamics and Function on Retinal Ganglion Cell Susceptibility in Optic Nerve Disease. Cells 2021; 10:cells10071593. [PMID: 34201955 PMCID: PMC8306483 DOI: 10.3390/cells10071593] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/15/2021] [Accepted: 06/17/2021] [Indexed: 12/30/2022] Open
Abstract
The important roles of mitochondrial function and dysfunction in the process of neurodegeneration are widely acknowledged. Retinal ganglion cells (RGCs) appear to be a highly vulnerable neuronal cell type in the central nervous system with respect to mitochondrial dysfunction but the actual reasons for this are still incompletely understood. These cells have a unique circumstance where unmyelinated axons must bend nearly 90° to exit the eye and then cross a translaminar pressure gradient before becoming myelinated in the optic nerve. This region, the optic nerve head, contains some of the highest density of mitochondria present in these cells. Glaucoma represents a perfect storm of events occurring at this location, with a combination of changes in the translaminar pressure gradient and reassignment of the metabolic support functions of supporting glia, which appears to apply increased metabolic stress to the RGC axons leading to a failure of axonal transport mechanisms. However, RGCs themselves are also extremely sensitive to genetic mutations, particularly in genes affecting mitochondrial dynamics and mitochondrial clearance. These mutations, which systemically affect the mitochondria in every cell, often lead to an optic neuropathy as the sole pathologic defect in affected patients. This review summarizes knowledge of mitochondrial structure and function, the known energy demands of neurons in general, and places these in the context of normal and pathological characteristics of mitochondria attributed to RGCs.
Collapse
Affiliation(s)
- Nicole A. Muench
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
| | - Sonia Patel
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
| | - Margaret E. Maes
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria;
| | - Ryan J. Donahue
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
- Boston Children’s Hospital, Harvard Medical School, Harvard University, Boston, MA 02115, USA
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA;
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Robert W. Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
- Correspondence:
| |
Collapse
|
14
|
Carrella S, Massa F, Indrieri A. The Role of MicroRNAs in Mitochondria-Mediated Eye Diseases. Front Cell Dev Biol 2021; 9:653522. [PMID: 34222230 PMCID: PMC8249810 DOI: 10.3389/fcell.2021.653522] [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: 01/14/2021] [Accepted: 05/20/2021] [Indexed: 12/15/2022] Open
Abstract
The retina is among the most metabolically active tissues with high-energy demands. The peculiar distribution of mitochondria in cells of retinal layers is necessary to assure the appropriate energy supply for the transmission of the light signal. Photoreceptor cells (PRs), retinal pigment epithelium (RPE), and retinal ganglion cells (RGCs) present a great concentration of mitochondria, which makes them particularly sensitive to mitochondrial dysfunction. To date, visual loss has been extensively correlated to defective mitochondrial functions. Many mitochondrial diseases (MDs) show indeed neuro-ophthalmic manifestations, including retinal and optic nerve phenotypes. Moreover, abnormal mitochondrial functions are frequently found in the most common retinal pathologies, i.e., glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR), that share clinical similarities with the hereditary primary MDs. MicroRNAs (miRNAs) are established as key regulators of several developmental, physiological, and pathological processes. Dysregulated miRNA expression profiles in retinal degeneration models and in patients underline the potentiality of miRNA modulation as a possible gene/mutation-independent strategy in retinal diseases and highlight their promising role as disease predictive or prognostic biomarkers. In this review, we will summarize the current knowledge about the participation of miRNAs in both rare and common mitochondria-mediated eye diseases. Definitely, given the involvement of miRNAs in retina pathologies and therapy as well as their use as molecular biomarkers, they represent a determining target for clinical applications.
Collapse
Affiliation(s)
| | - Filomena Massa
- Telethon Institute of Genetics and Medicine, Naples, Italy
| | - Alessia Indrieri
- Telethon Institute of Genetics and Medicine, Naples, Italy.,Institute for Genetic and Biomedical Research, National Research Council (CNR), Milan, Italy
| |
Collapse
|
15
|
Neuroprotection in Glaucoma: NAD +/NADH Redox State as a Potential Biomarker and Therapeutic Target. Cells 2021; 10:cells10061402. [PMID: 34198948 PMCID: PMC8226607 DOI: 10.3390/cells10061402] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/24/2021] [Accepted: 05/27/2021] [Indexed: 02/07/2023] Open
Abstract
Glaucoma is the leading cause of irreversible blindness worldwide. Its prevalence and incidence increase exponentially with age and the level of intraocular pressure (IOP). IOP reduction is currently the only therapeutic modality shown to slow glaucoma progression. However, patients still lose vision despite best treatment, suggesting that other factors confer susceptibility. Several studies indicate that mitochondrial function may underlie both susceptibility and resistance to developing glaucoma. Mitochondria meet high energy demand, in the form of ATP, that is required for the maintenance of optimum retinal ganglion cell (RGC) function. Reduced nicotinamide adenine dinucleotide (NAD+) levels have been closely correlated to mitochondrial dysfunction and have been implicated in several neurodegenerative diseases including glaucoma. NAD+ is at the centre of various metabolic reactions culminating in ATP production—essential for RGC function. In this review we present various pathways that influence the NAD+(H) redox state, affecting mitochondrial function and making RGCs susceptible to degeneration. Such disruptions of the NAD+(H) redox state are generalised and not solely induced in RGCs because of high IOP. This places the NAD+(H) redox state as a potential systemic biomarker for glaucoma susceptibility and progression; a hypothesis which may be tested in clinical trials and then translated to clinical practice.
Collapse
|
16
|
Abstract
This review focuses on recent progress in understanding the role of mitochondrial markers in the context of mitochondrial dysfunction in glaucoma and discussing new therapeutic approaches to modulate mitochondrial function and potentially lead to improved outcomes in glaucoma.
Collapse
|
17
|
Chen M, Yu X, Xu J, Ma J, Chen X, Chen B, Gu Y, Wang K. Association of Gene Polymorphisms With Primary Open Angle Glaucoma: A Systematic Review and Meta-Analysis. ACTA ACUST UNITED AC 2019; 60:1105-1121. [PMID: 30901387 DOI: 10.1167/iovs.18-25922] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Min Chen
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| | - Xiaoning Yu
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| | - Jia Xu
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| | - Jian Ma
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| | - Xinyi Chen
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| | - Binbin Chen
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| | - Yuxiang Gu
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| | - Kaijun Wang
- Eye Center, the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, China
| |
Collapse
|
18
|
Martins A, Rodrigues TM, Soares M, Dolan MJ, Murta JN, Silva R, Marques JP. Peripapillary and macular morpho-vascular changes in patients with genetic or clinical diagnosis of autosomal dominant optic atrophy: a case-control study. Graefes Arch Clin Exp Ophthalmol 2019; 257:1019-1027. [DOI: 10.1007/s00417-019-04267-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/22/2018] [Accepted: 02/09/2019] [Indexed: 12/14/2022] Open
|
19
|
Trivli A, Koliarakis I, Terzidou C, Goulielmos GN, Siganos CS, Spandidos DA, Dalianis G, Detorakis ET. Normal-tension glaucoma: Pathogenesis and genetics. Exp Ther Med 2018; 17:563-574. [PMID: 30651837 PMCID: PMC6307418 DOI: 10.3892/etm.2018.7011] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/21/2018] [Indexed: 12/27/2022] Open
Abstract
Normal-tension glaucoma (NTG) is a multifactorial optic neuropathy which, similar to open-angle glaucomas, is characterized by progressive retinal ganglion cell death and glaucomatous visual field loss. The major distinction of NTG from open-angle glaucomas is that the intraocular pressure (IOP) does not exceed the normal range. Missing the major risk factor and target of therapy, the elevated IOP, NTG poses a clinical challenge. Several insightful reviews have been published on the pathophysiology of NTG describing the possible underlying mechanisms. The current literature available also suggests that a significant percentage of patients with NTG (as high as 21%) have a family history of glaucoma, indicating a genetic predisposition to the disease. These facts strengthen the indication that NTG remains an enigmatic process. The aim of this review was to summarize the vascular, mechanical and genetic components considered to be responsible for NTG development and to discuss the mechanisms through which they are involved in the pathogenesis of NTG.
Collapse
Affiliation(s)
- Alexandra Trivli
- Department of Ophthalmology, Konstantopouleio-Patission General Hospital, 14233 Athens, Greece.,Section of Molecular Pathology and Human Genetics, Department of Internal Medicine, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Ioannis Koliarakis
- Laboratory of Anatomy-Histology-Embryology, Medical School, University of Crete, 71003 Heraklion, Greece
| | - Chryssa Terzidou
- Department of Ophthalmology, Konstantopouleio-Patission General Hospital, 14233 Athens, Greece
| | - George N Goulielmos
- Section of Molecular Pathology and Human Genetics, Department of Internal Medicine, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Charalambos S Siganos
- Department of Ophthalmology, University Hospital of Heraklion, 71110 Heraklion, Greece
| | - Demetrios A Spandidos
- Laboratory of Clinical Virology, Medical School, University of Crete, 71003 Heraklion, Greece
| | - Georgios Dalianis
- Department of Ophthalmology, Konstantopouleio-Patission General Hospital, 14233 Athens, Greece
| | | |
Collapse
|
20
|
Wang HW, Sun P, Chen Y, Jiang LP, Wu HP, Zhang W, Gao F. Research progress on human genes involved in the pathogenesis of glaucoma (Review). Mol Med Rep 2018; 18:656-674. [PMID: 29845210 PMCID: PMC6059695 DOI: 10.3892/mmr.2018.9071] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/12/2018] [Indexed: 12/20/2022] Open
Abstract
Glaucoma is the leading cause of irreversible blindness globally. It is known that the incidence of glaucoma is closely associated with inheritance. A large number of studies have suggested that genetic factors are involved in the occurrence and development of glaucoma, and even affect the drug sensitivity and prognosis of glaucoma. In the present review, 22 loci of glaucoma are presented, including the relevant genes (myocilin, interleukin 20 receptor subunit B, optineurin, ankyrin repeat- and SOCS box-containing protein 10, WD repeat-containing protein 36, EGF-containing fibulin-like extracellular matrix protein 1, neurotrophin 4, TANK-binding kinase 1, cytochrome P450 subfamily I polypeptide 1, latent transforming growth factor β binding protein 2 and TEK tyrosine kinase endothelial) and 74 other genes (including toll-like receptor 4, sine oculis homeobox Drosophila homolog of 1, doublecortin-like kinase 1, RE repeats-encoding gene, retinitis pigmentosa GTPase regulator-interacting protein, lysyl oxidase-like protein 1, heat-shock 70-kDa protein 1A, baculoviral IAP repeat-containing protein 6, 5,10-methylenetetrahydrofolate reductase and nitric oxide synthase 3 and nanophthalmos 1) that are more closely associated with glaucoma. The pathogenesis of these glaucoma-associated genes, glaucomatous genetics and genetic approaches, as well as glaucomatous risk factors, including increasing age, glaucoma family history, high myopia, diabetes, ocular trauma, smoking, intraocular pressure increase and/or fluctuation were also discussed.
Collapse
Affiliation(s)
- Hong-Wei Wang
- Department of Ophthalmology, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Peng Sun
- Department of Ophthalmology, Longgang District People's Hospital, Shenzhen, Guangdong 518172, P.R. China
| | - Yao Chen
- Department of Ophthalmology, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Li-Ping Jiang
- Department of Ophthalmology, The First Affiliated Hospital of Qiqihar Medical University, Qiqihar, Heilongjiang 161041, P.R. China
| | - Hui-Ping Wu
- Department of The Scientific Research, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Wen Zhang
- Medical School, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Feng Gao
- Department of Hospital Administration, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| |
Collapse
|
21
|
Williams PA, Harder JM, John SWM. Glaucoma as a Metabolic Optic Neuropathy: Making the Case for Nicotinamide Treatment in Glaucoma. J Glaucoma 2017; 26:1161-1168. [PMID: 28858158 PMCID: PMC5854489 DOI: 10.1097/ijg.0000000000000767] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mitochondrial dysfunction may be an important, if not essential, component of human glaucoma. Using transcriptomics followed by molecular and neurobiological techniques, we have recently demonstrated that mitochondrial dysfunction within retinal ganglion cells is an early feature in the DBA/2J mouse model of inherited glaucoma. Guided by these findings, we discovered that the retinal level of nicotinamide adenine dinucleotide (NAD, a key molecule for mitochondrial health) declines in an age-dependent manner. We hypothesized that this decline in NAD renders retinal ganglion cells susceptible to damage during periods of elevated intraocular pressure. To replete NAD levels in this glaucoma, we administered nicotinamide (the amide of vitamin B3). At the lowest dose tested, nicotinamide robustly protected from glaucoma (~70% of eyes had no detectable glaucomatous neurodegeneration). At this dose, nicotinamide had no influence on intraocular pressure and so its effect was neuroprotective. At the highest dose tested, 93% of eyes had no detectable glaucoma. This represents a ~10-fold decrease in the risk of developing glaucoma. At this dose, intraocular pressure still became elevated but there was a reduction in the degree of elevation showing an additional benefit. Thus, nicotinamide is unexpectedly potent at preventing this glaucoma and is an attractive option for glaucoma therapeutics. Our findings demonstrate the promise for both preventing and treating glaucoma by interventions that bolster metabolism during increasing age and during periods of elevated intraocular pressure. Nicotinamide prevents age-related declines in NAD (a decline that occurs in different genetic contexts and species). NAD precursors are reported to protect from a variety of neurodegenerative conditions. Thus, nicotinamide may provide a much needed neuroprotective treatment against human glaucoma. This manuscript summarizes human data implicating mitochondria in glaucoma, and argues for studies to further assess the safety and efficacy of nicotinamide in human glaucoma care.
Collapse
Affiliation(s)
- Pete A Williams
- The Howard Hughes Medical Institute, The Jackson Laboratory, Bar Harbor, ME, USA
| | - Jeffrey M Harder
- The Howard Hughes Medical Institute, The Jackson Laboratory, Bar Harbor, ME, USA
| | - Simon W M John
- The Howard Hughes Medical Institute, The Jackson Laboratory, Bar Harbor, ME, USA
- Department of Ophthalmology, Tufts University of Medicine, Boston, MA, USA
| |
Collapse
|
22
|
Pretegiani E, Rosini F, Rufa A, Gallus G, Cardaioli E, Da Pozzo P, Bianchi S, Serchi V, Collura M, Franceschini R, Bianchi Marzoli S, Dotti M, Federico A. Genotype-phenotype and OCT correlations in Autosomal Dominant Optic Atrophy related to OPA1 gene mutations: Report of 13 Italian families. J Neurol Sci 2017; 382:29-35. [DOI: 10.1016/j.jns.2017.09.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 09/09/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
|
23
|
Wang J, Qu D, An J, Yuan G, Liu Y. Integrated microarray analysis provided novel insights to the pathogenesis of glaucoma. Mol Med Rep 2017; 16:8735-8746. [PMID: 28990066 PMCID: PMC5779953 DOI: 10.3892/mmr.2017.7711] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 08/15/2017] [Indexed: 11/10/2022] Open
Abstract
Glaucoma is characterized as a visual field defect, which is the second most common cause of blindness. The present study performed an integrated analysis of microarray studies of glaucoma derived from Gene Expression Omnibus (GEO). Following the identification of the differentially expressed genes (DEGs) in glaucoma compared with normal control (NC) tissues, the functional annotation, glaucoma-specific protein-protein interaction (PPI) network and transcriptional regulatory network constructions were performed. The acute intraocular pressure (IOP) elevation rat models were established and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed for DEGs expression confirmation. Three datasets were downloaded from GEO. A total of 97 DEGs, 82 upregulated and 15 downregulated were identified in glaucoma compared with NC groups with false discovery rate <0.05. Response to virus and immune response were two significantly enriched GO terms in glaucoma. Valine, leucine and isoleucine degradation was a significantly enriched pathway of DEGs in glaucoma. According to the PPI network, HDAC1, HBN, UBR4 and PDK1 were hub proteins in glaucoma. FOXD3, HNF-4 and AP-1 were the three transcription factors (TFs) derived from top 10 TFs which covered the majority of downstream DEGs in glaucoma. Based on the RT-qPCR results, the expression levels of 3 DEGs, raftlin, lipid raft linker 1 (RFTN1), PBX homeobox 1 (PBX1), HDAC1 were significantly upregulated and the expression of GEM was significantly downregulated in acute IOP elevation rat model at the first and fifth day. These four DEGs had the same expression pattern with our integrated analysis. Therefore, the current study concluded that 6 DEGs, including HEPH, SELENBP1, RFTN1, ID1, HDAC-1 and PBX1 and three TFs, including FOXD3, HNF-4 and AP-1 may be involved with the pathogenesis of glaucoma. The findings of the current study may improve diagnosis and drug design for glaucoma.
Collapse
Affiliation(s)
- Jinhui Wang
- Department of Clinical Laboratory, The First Hospital of Harbin, Harbin, Heilongjiang 150001, P.R. China
| | - Daofei Qu
- Department of Ophthalmology, The First Hospital of Harbin, Harbin, Heilongjiang 150001, P.R. China
| | - Jinghong An
- Department of Clinical Laboratory, The First Hospital of Harbin, Harbin, Heilongjiang 150001, P.R. China
| | - Guoming Yuan
- Department of Clinical Laboratory, The First Hospital of Harbin, Harbin, Heilongjiang 150001, P.R. China
| | - Yufu Liu
- Department of Ophthalmology, The First Hospital of Harbin, Harbin, Heilongjiang 150001, P.R. China
| |
Collapse
|
24
|
Pilz YL, Bass SJ, Sherman J. A Review of Mitochondrial Optic Neuropathies: From Inherited to Acquired Forms. JOURNAL OF OPTOMETRY 2017; 10:205-214. [PMID: 28040497 PMCID: PMC5595256 DOI: 10.1016/j.optom.2016.09.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 09/02/2016] [Accepted: 09/22/2016] [Indexed: 05/28/2023]
Abstract
In recent years, the term mitochondrial optic neuropathy (MON) has increasingly been used within the literature to describe a group of optic neuropathies that exhibit mitochondrial dysfunction in retinal ganglion cells (RGCs). Interestingly, MONs include genetic aetiologies, such as Leber hereditary optic neuropathy (LHON) and dominant optic atrophy (DOA), as well as acquired aetiologies resulting from drugs, nutritional deficiencies, and mixed aetiologies. Regardless of an inherited or acquired cause, patients exhibit the same clinical manifestations with selective loss of the RGCs due to mitochondrial dysfunction. Various novel therapies are being explored to reverse or limit damage to the RGCs. Here we review the pathophysiology, clinical manifestations, differential diagnosis, current treatment, and promising therapeutic targets of MON.
Collapse
MESH Headings
- DNA, Mitochondrial
- Diagnosis, Differential
- Humans
- Mitochondrial Diseases/diagnosis
- Mitochondrial Diseases/genetics
- Mitochondrial Diseases/physiopathology
- Mitochondrial Diseases/therapy
- Optic Atrophy, Autosomal Dominant/diagnosis
- Optic Atrophy, Autosomal Dominant/genetics
- Optic Atrophy, Autosomal Dominant/physiopathology
- Optic Atrophy, Autosomal Dominant/therapy
- Optic Atrophy, Hereditary, Leber/diagnosis
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/physiopathology
- Optic Atrophy, Hereditary, Leber/therapy
- Optic Nerve Diseases/diagnosis
- Optic Nerve Diseases/genetics
- Optic Nerve Diseases/physiopathology
- Optic Nerve Diseases/therapy
- Retinal Ganglion Cells/pathology
Collapse
Affiliation(s)
- Yasmine L Pilz
- State University New York, College of Optometry, New York, USA.
| | - Sherry J Bass
- State University New York, College of Optometry, New York, USA
| | - Jerome Sherman
- State University New York, College of Optometry, New York, USA
| |
Collapse
|
25
|
Maes ME, Schlamp CL, Nickells RW. BAX to basics: How the BCL2 gene family controls the death of retinal ganglion cells. Prog Retin Eye Res 2017; 57:1-25. [PMID: 28064040 DOI: 10.1016/j.preteyeres.2017.01.002] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 12/19/2022]
Abstract
Retinal ganglion cell (RGC) death is the principal consequence of injury to the optic nerve. For several decades, we have understood that the RGC death process was executed by apoptosis, suggesting that there may be ways to therapeutically intervene in this cell death program and provide a more direct treatment to the cells and tissues affected in diseases like glaucoma. A major part of this endeavor has been to elucidate the molecular biological pathways active in RGCs from the point of axonal injury to the point of irreversible cell death. A major component of this process is the complex interaction of members of the BCL2 gene family. Three distinct family members of proteins orchestrate the most critical junction in the apoptotic program of RGCs, culminating in the activation of pro-apoptotic BAX. Once active, BAX causes irreparable damage to mitochondria, while precipitating downstream events that finish off a dying ganglion cell. This review is divided into two major parts. First, we summarize the extent of knowledge of how BCL2 gene family proteins interact to facilitate the activation and function of BAX. This area of investigation has rapidly changed over the last few years and has yielded a dramatically different mechanistic understanding of how the intrinsic apoptotic program is run in mammalian cells. Second, we provided a comprehensive analysis of nearly two decades of investigation of the role of BAX in the process of RGC death, much of which has provided many important insights into the overall pathophysiology of diseases like glaucoma.
Collapse
Affiliation(s)
- Margaret E Maes
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Cassandra L Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA.
| |
Collapse
|
26
|
Finsterer J, Zarrouk-Mahjoub S, Daruich A. The Eye on Mitochondrial Disorders. J Child Neurol 2016; 31:652-62. [PMID: 26275973 DOI: 10.1177/0883073815599263] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 07/08/2015] [Indexed: 11/16/2022]
Abstract
Ophthalmologic manifestations of mitochondrial disorders are frequently neglected or overlooked because they are often not regarded as part of the phenotype. This review aims at summarizing and discussing the etiology, pathogenesis, diagnosis, and treatment of ophthalmologic manifestations of mitochondrial disorders. Review of publications about ophthalmologic involvement in mitochondrial disorders by search of Medline applying appropriate search terms. The eye is frequently affected by syndromic as well as nonsyndromic mitochondrial disorders. Primary and secondary ophthalmologic manifestations can be differentiated. The most frequent ophthalmologic manifestations of mitochondrial disorders include ptosis, progressive external ophthalmoplegia, optic atrophy, retinopathy, and cataract. More rarely occurring are nystagmus and abnormalities of the cornea, ciliary body, intraocular pressure, the choroidea, or the brain secondarily affecting the eyes. It is important to recognize and diagnose ophthalmologic manifestations of mitochondrial disorders as early as possible because most are accessible to symptomatic treatment with partial or complete short-term or long-term beneficial effect. Ophthalmologic manifestations of mitochondrial disorders need to be appropriately diagnosed to initiate the most effective management and guarantee optimal outcome.
Collapse
Affiliation(s)
| | | | - Alejandra Daruich
- Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Switzerland
| |
Collapse
|
27
|
Zhang AM, Bi R, Hu QX, Fan Y, Zhang Q, Yao YG. The OPA1 Gene Mutations Are Frequent in Han Chinese Patients with Suspected Optic Neuropathy. Mol Neurobiol 2016; 54:1622-1630. [DOI: 10.1007/s12035-016-9771-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/02/2016] [Indexed: 12/24/2022]
|
28
|
Abstract
Mitochondrial dysfunction underlies many human disorders, including those that affect the visual system. The retinal ganglion cells, whose axons form the optic nerve, are often damaged by mitochondrial-related diseases which result in blindness. Both mitochondrial DNA (mtDNA) and nuclear gene mutations impacting many different mitochondrial processes can result in optic nerve disease. Of particular importance are mutations that impair mitochondrial network dynamics (fusion and fission), oxidative phosphorylation (OXPHOS), and formation of iron-sulfur complexes. Current genetic knowledge can inform genetic counseling and suggest strategies for novel gene-based therapies. Identifying new optic neuropathy-causing genes and defining the role of current and novel genes in disease will be important steps toward the development of effective and potentially neuroprotective therapies.
Collapse
Affiliation(s)
- Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear, Boston, Massachusetts 02114;
| |
Collapse
|
29
|
Kim KY, Perkins GA, Shim MS, Bushong E, Alcasid N, Ju S, Ellisman MH, Weinreb RN, Ju WK. DRP1 inhibition rescues retinal ganglion cells and their axons by preserving mitochondrial integrity in a mouse model of glaucoma. Cell Death Dis 2015; 6:e1839. [PMID: 26247724 PMCID: PMC4558491 DOI: 10.1038/cddis.2015.180] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/13/2015] [Accepted: 05/18/2015] [Indexed: 11/09/2022]
Abstract
Glaucoma is the leading cause of irreversible blindness and is characterized by slow and progressive degeneration of the optic nerve head axons and retinal ganglion cell (RGC), leading to loss of visual function. Although oxidative stress and/or alteration of mitochondrial (mt) dynamics induced by elevated intraocular pressure (IOP) are associated with this neurodegenerative disease, the mechanisms that regulate mt dysfunction-mediated glaucomatous neurodegeneration are poorly understood. Using a mouse model of glaucoma, DBA/2J (D2), which spontaneously develops elevated IOP, as well as an in vitro RGC culture system, we show here that oxidative stress, as evidenced by increasing superoxide dismutase 2 (SOD2) and mt transcription factor A (Tfam) protein expression, triggers mt fission and loss by increasing dynamin-related protein 1 (DRP1) in the retina of glaucomatous D2 mice as well as in cultured RGCs exposed to elevated hydrostatic pressure in vitro. DRP1 inhibition by overexpressing DRP1 K38A mutant blocks mt fission and triggers a subsequent reduction of oxidative stress, as evidenced by decreasing SOD2 and Tfam protein expression. DRP1 inhibition promotes RGC survival by increasing phosphorylation of Bad at serine 112 in the retina and preserves RGC axons by maintaining mt integrity in the glial lamina of glaucomatous D2 mice. These findings demonstrate an important vicious cycle involved in glaucomatous neurodegeneration that starts with elevated IOP producing oxidative stress; the oxidative stress then leads to mt fission and a specific form of mt dysfunction that generates further oxidative stress, thus perpetuating the cycle. Our findings suggest that DRP1 is a potential therapeutic target for ameliorating oxidative stress-mediated mt fission and dysfunction in RGC and its axons during glaucomatous neurodegeneration. Thus, DRP1 inhibition may provide a new therapeutic strategy for protecting both RGCs and their axons in glaucoma and other optic neuropathies.
Collapse
Affiliation(s)
- K-Y Kim
- Department of Neuroscience, Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - G A Perkins
- Department of Neuroscience, Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - M S Shim
- Laboratory for Optic Nerve Biology, Department of Ophthalmology, Hamilton Glaucoma Center, University of California, San Diego, La Jolla, CA, USA
| | - E Bushong
- Department of Neuroscience, Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - N Alcasid
- Department of Neuroscience, Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - S Ju
- Department of Neuroscience, Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - M H Ellisman
- Department of Neuroscience, Center for Research in Biological Systems, National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - R N Weinreb
- Laboratory for Optic Nerve Biology, Department of Ophthalmology, Hamilton Glaucoma Center, University of California, San Diego, La Jolla, CA, USA
| | - W-K Ju
- Laboratory for Optic Nerve Biology, Department of Ophthalmology, Hamilton Glaucoma Center, University of California, San Diego, La Jolla, CA, USA
| |
Collapse
|
30
|
Sakurada Y, Mabuchi F. Advances in glaucoma genetics. PROGRESS IN BRAIN RESEARCH 2015; 220:107-26. [DOI: 10.1016/bs.pbr.2015.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
31
|
Chandra A, Mitry D, Wright A, Campbell H, Charteris DG. Genome-wide association studies: applications and insights gained in Ophthalmology. Eye (Lond) 2014; 28:1066-79. [PMID: 24971990 DOI: 10.1038/eye.2014.145] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 05/18/2014] [Indexed: 12/20/2022] Open
Abstract
Genome-wide association studies (GWAS) use high-throughput genotyping technologies to genotype thousands of single-nucleotide polymorphisms (SNPs) and relate them to the development of clinical and quantitative traits. Their use has been highly successful in the field of ophthalmology, and since the advent of GWAS in 2005, many genes not previously suspected of having a role in disease have been identified and the findings replicated. We conducted an extensive literature review and describe the concept, design, advantages, and limitations of GWAS and provide a detailed description of the applications and discoveries of GWAS in the field of eye disease to date. There have been many novel findings revealing previously unknown biological insights in a diverse range of common ocular conditions. GWAS have been a highly successful modality for investigating the pathogenesis of a wide variety of ophthalmic conditions. The insights gained into the pathogenesis of disease provide not only a better understanding of underlying disease mechanism but also offer a rationale for targeted treatment and preventative strategies. Expansive international collaboration and standardised phenotyping will permit the continued success of this investigative technique.
Collapse
Affiliation(s)
- A Chandra
- 1] Department of Ophthalmology, Moorfields Eye Hospital, London, UK [2] UCL Institute of Ophthalmology, London, UK
| | - D Mitry
- 1] Department of Ophthalmology, Moorfields Eye Hospital, London, UK [2] Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - A Wright
- Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, UK
| | - H Campbell
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - D G Charteris
- Department of Ophthalmology, Moorfields Eye Hospital, London, UK
| |
Collapse
|
32
|
Takamoto M, Araie M. Genetics of primary open angle glaucoma. Jpn J Ophthalmol 2013; 58:1-15. [DOI: 10.1007/s10384-013-0286-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/17/2013] [Indexed: 04/21/2023]
|
33
|
Janssen SF, Gorgels TG, Ramdas WD, Klaver CC, van Duijn CM, Jansonius NM, Bergen AA. The vast complexity of primary open angle glaucoma: Disease genes, risks, molecular mechanisms and pathobiology. Prog Retin Eye Res 2013; 37:31-67. [DOI: 10.1016/j.preteyeres.2013.09.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 07/26/2013] [Accepted: 09/03/2013] [Indexed: 12/21/2022]
|
34
|
Quirós PM, Ramsay AJ, López-Otín C. New roles for OMA1 metalloprotease: From mitochondrial proteostasis to metabolic homeostasis. Adipocyte 2013; 2:7-11. [PMID: 23700547 PMCID: PMC3661128 DOI: 10.4161/adip.21999] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The mitochondrial quality control system is essential for the preservation and regulation of mitochondrial function. This system is formed by a complex machinery that controls and maintains protein function and regulates mitochondrial morphology through a coordinated system of continual fusion and fission events. Impairments in the mitochondrial quality control system through either mutation or deficiency in any of its components, can lead to mitochondrial dysfunction. However, the physiological consequences of these deficiencies remain unknown in most cases. Here, we briefly review the role of the OPA1-OMA1 system in mitochondrial biology, and summarize our recent report on the generation and phenotypic characterization of a model deficient in OMA1, an ATP-independent mitochondrial metalloprotease that participates in mitochondrial quality control. Interestingly, Oma1-deficient mice display an obesity phenotype, characterized by hepatic steatosis, decrease in energy expenditure and defective thermogenic regulation. In addition, our study has provided in vivo evidence of OMA1 function as a mitochondrial quality control protease, inactivating OPA1 under stress conditions and inhibiting mitochondrial fusion. Further, we have demonstrated the essential role of the OMA1-OPA1 system for brown adipose function and how this system regulates metabolic homeostasis in mice.
Collapse
|
35
|
Association of OPA1 polymorphisms with NTG and HTG: a meta-analysis. PLoS One 2012; 7:e42387. [PMID: 22879959 PMCID: PMC3411762 DOI: 10.1371/journal.pone.0042387] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 07/04/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Genetic polymorphisms of the Optic atrophy 1 gene have been implicated in altering the risk of primary open angle glaucoma (POAG), especially the susceptibility to normal tension glaucoma (NTG), but the results remain controversial. METHODS Multiple electronic databases (up to January 20, 2012) were searched independently by two investigators. A meta-analysis was performed on the association between Optic atrophy 1 polymorphisms (rs 166850 and rs 10451941) and normal tension glaucoma (NTG)/high tension glaucoma (HTG). Summary odds ratios (ORs) and 95% confidence intervals (CI) were estimated. RESULTS Seven studies of 713 cases and 964 controls for NTG and five studies of 1200 cases and 971 controls for HTG on IVS8+4C>T (rs 166850) and IVS8+32T>C (rs10451941) were identified. There were significant associations between the OPA1 rs10451941polymorphism and NTG susceptibility for all genetic models(C vs. T OR = 1.26, 95% CI 1.09-1.47, p = 0.002; CC vs. TT: OR = 1.52, 95% CI 1.04-2.20, p = 0.029; CC vs. CT+TT: OR = 1.64, 95% CI 1.16-2.33, p = 0.005; CC+CT vs. TT: OR = 1.21, 95% CI 1.02-1.44, p = 0.032). However, no evidence of associations was detected between the OPA1 IVS8+32C>T polymorphism and POAG susceptibility to HTG. Similarly, clear associations between the rs 166850 variant and NTG were observed in allelic and dominant models (T vs. C OR = 1.52, 95% CI 1.16-1.99, p = 0.002; TT+TC vs. CC OR = 1.50, 95% CI 1.13-2.01, p = 0.006) but not to HTG. In subgroup analyses by ethnicity, we detected an association between both OPA1 polymorphisms and risk for NTG in Caucasians but not in Asians. By contrast, no significant findings were noted between OPA1 variants for HTG, either in Caucasians or in Asians. CONCLUSIONS Both the IVS8+4C>T and IVS8+32T>C variants may affect individual susceptibility to NTG. Moreover, stratified analyses for NTG detecting the effects of both OPA1 polymorphisms seemed to vary with ethnicity. Further investigations are needed to validate the association.
Collapse
|
36
|
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: 178] [Impact Index Per Article: 14.8] [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
|
37
|
Mitochondrial dysfunction in glaucoma: Understanding genetic influences. Mitochondrion 2012; 12:202-12. [DOI: 10.1016/j.mito.2011.11.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 11/11/2011] [Indexed: 12/27/2022]
|
38
|
Sitarz KS, Yu-Wai-Man P, Hudson G, Jacob A, Boggild M, Horvath R, Chinnery PF. Genetic variations within the OPA1 gene are not associated with neuromyelitis optica. Mult Scler 2012; 18:240-3. [PMID: 21828197 PMCID: PMC4040403 DOI: 10.1177/1352458511416838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Neuromyelitis optica (NMO) is an idiopathic demyelinating disease which predominantly affects the optic nerve and spinal cord. Multiplex NMO pedigrees have been reported but the genetic risk factors conferring this increased familial susceptibility have not yet been determined. OPA1 mutations have recently been identified in families with progressive visual failure and spastic paraparesis, raising the possibility that OPA1 genetic variants could contribute to the aetiology of NMO. We therefore screened for OPA1 in 32 patients with NMO. No pathogenic mutations were found, and none of the 13 single-nucleotide polymorphisms identified were associated with an increased risk of developing NMO.
Collapse
Affiliation(s)
- Kamil S Sitarz
- Mitochondrial Research Group, Institute of Genetic Medicine, Newcastle University, UK
| | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
PURPOSE OF REVIEW To provide an overview of the genetics of the primary open-angle glaucomas with particular attention to congenital, infantile, and juvenile forms. RECENT FINDINGS Mutations in CYP1B1, in addition to being the most common identifiable cause of autosomal recessive primary congenital/infantile glaucoma, can infrequently underlie juvenile and even primary adult-onset open-angle glaucoma, particularly in certain consanguineous populations. In 2009, patients diagnosed with congenital/infantile glaucoma were found to have recessive mutations in a second gene, LTBP2, with a phenotypic spectrum that includes primary megalocornea, spherophakia with ectopia lentis, and lens-related glaucoma. The most common identifiable cause of primary juvenile open-angle glaucoma across most populations remains heterozygous (autosomal dominant) MYOC mutation, underlying up to one-third of cases and possibly sometimes involved in earlier and later onset glaucomas Although primary adult-onset open-angle glaucoma usually does not follow simple Mendelian genetics and is etiologically complex, genome-wide association studies are uncovering genetic susceptibility factors. In some cases, primary adult-onset open-angle glaucoma can be caused by heterozygous mutation in MYOC, OPTN, or WDR36. In addition, in 2009, heterozygous NTF4 mutation was associated with the phenotype in a small percentage of patients from a German cohort. SUMMARY Seemingly unaffected siblings of children with CYP1B1-related primary congenital/infantile glaucoma should undergo genetic testing because of variable expressivity for the phenotype; such testing should also be considered for other asymptomatic relatives, especially in consanguineous families. In western populations, dominant MYOC mutation remains a common cause of primary open-angle juvenile glaucoma and infrequently can be implicated in congenital/infantile or adult-onset forms; identified families should undergo genetic counseling. Primary adult-onset open-angle glaucoma rarely follows simple Mendelian genetics, but genomic studies in different populations are revealing potential genetic risk factors for the phenotype.
Collapse
|
40
|
Bosley TM, Hellani A, Spaeth GL, Myers J, Katz LJ, Moster MR, Milcarek B, Abu-Amero KK. Down-regulation of OPA1 in patients with primary open angle glaucoma. Mol Vis 2011; 17:1074-9. [PMID: 21552501 PMCID: PMC3086630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/18/2011] [Indexed: 11/14/2022] Open
Abstract
PURPOSE Heterozygous optic atrophy type1 (OPA1) mutations are responsible for dominant optic atrophy, and the down regulation of OPA1 expression in patients with Leber hereditary optic neuropathy may imply that Opa1 protein levels in mitochondria play a role in other spontaneous optic neuropathies as well. Mitochondrial and metabolic abnormalities may put the optic nerve at risk in primary open angle glaucoma (POAG), and this preliminary study was designed to investigate whether altered OPA1 expression might be present in the progressive optic neuropathy of POAG. METHODS Patients were eligible for inclusion if they met standard clinical criteria for POAG, including age greater than 40 years, intraocular pressure ≥ 21 mmHg in at least one eye before treatment, normal-appearing anterior chamber angles bilaterally on gonioscopy, and optic nerve injury characteristic of POAG. RNA was extracted from leukocytes and converted to cDNA by reverse transcriptase enzyme, and real time PCR was used to assess expression levels of OPA1 and the β-globulin (HBB) housekeeping gene. The ratio of OPA1 expression to HBB expression (OPA1/HBB) for POAG patients was compared to that of controls and to clinical characteristics of POAG patients. RESULTS Forty-three POAG patients and 27 controls were completely phenotyped with a full ophthalmologic examination and static perimetry. Mean age (POAG 67.9 years; controls 61.8 years) and sex (POAG 26 males/17 females; controls 11/16) were similar for the two groups. Mean OPA1/HBB of POAG patients (1.16, SD 0.26) was 18% lower than controls (1.41, SD 0.50), and this difference was statistically significant (p≤0.021). OPA1 expression differed between the groups (p≤0.037), but HBB expression did not differ (p≤0.24). OPA1/HBB was not correlated with any clinical feature of POAG patients. CONCLUSIONS Transcriptional analysis of peripheral blood leucocytes is a limited model system for studying the consequences of mitochondrial abnormalities in the optic nerve. Nevertheless, OPA1 is known to affect mitochondrial stability and has now been implicated in several spontaneous optic neuropathies. Decreased OPA1 expression in POAG patients is another indication that mitochondrial function, and possibly mitochondrially-induced apoptosis, may play a role in the development of POAG.
Collapse
Affiliation(s)
- Thomas M. Bosley
- Ophthalmic Genetics Laboratory and Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia,Division of Neurology, Cooper University Hospital, Camden, NJ
| | - Ali Hellani
- PGD Laboratory, Saad Specialist Hospital, Al-Khobar, Saudi Arabia
| | - George L. Spaeth
- William and Anna Goldberg Glaucoma Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA
| | - Jonathan Myers
- William and Anna Goldberg Glaucoma Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA
| | - L. Jay Katz
- William and Anna Goldberg Glaucoma Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA
| | - Marlene R. Moster
- William and Anna Goldberg Glaucoma Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA
| | - Barry Milcarek
- Research Department, Cooper University Hospital, Camden, NJ
| | - Khaled K. Abu-Amero
- Ophthalmic Genetics Laboratory and Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia,Department of Ophthalmology, University of Florida-College of Medicine, Jacksonville, FL
| |
Collapse
|
41
|
Rao KN, Nagireddy S, Chakrabarti S. Complex genetic mechanisms in glaucoma: an overview. Indian J Ophthalmol 2011; 59 Suppl:S31-42. [PMID: 21150032 PMCID: PMC3038510 DOI: 10.4103/0301-4738.73685] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Glaucomas comprise a group of hereditary optic neuropathies characterized by progressive and irreversible visual field loss and damage to the optic nerve head. It is a complex disease with multiple molecular mechanisms underlying its pathogenesis. Genetic heterogeneity is the hallmark of all glaucomas and multiple chromosomal loci have been linked to the disease, but only a few genes have been characterized, viz. myocilin (MYOC), optineurin (OPTN), WDR36 and neurotrophin-4 (NTF4) in primary open angle glaucoma (POAG) and CYP1B1 and LTBP2 in congenital and developmental glaucomas. Case-control-based association studies on candidate genes involved in different stages of glaucoma pathophysiology have indicated a very limited involvement. The complex mechanisms leading to glaucoma pathogenesis indicate that it could be attributed to multiple genes with varying magnitudes of effect. In this review, we provide an appraisal of the various efforts in unraveling the molecular mystery in glaucoma and also some future directions based on the available scientific knowledge and technological developments.
Collapse
Affiliation(s)
- Kollu N Rao
- Kallam Anji Reddy Molecular Genetics Laboratory, Prof Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
| | | | | |
Collapse
|
42
|
Yu-Wai-Man P, Griffiths PG, Chinnery PF. Mitochondrial optic neuropathies - disease mechanisms and therapeutic strategies. Prog Retin Eye Res 2011; 30:81-114. [PMID: 21112411 PMCID: PMC3081075 DOI: 10.1016/j.preteyeres.2010.11.002] [Citation(s) in RCA: 440] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leber hereditary optic neuropathy (LHON) and autosomal-dominant optic atrophy (DOA) are the two most common inherited optic neuropathies in the general population. Both disorders share striking pathological similarities, marked by the selective loss of retinal ganglion cells (RGCs) and the early involvement of the papillomacular bundle. Three mitochondrial DNA (mtDNA) point mutations; m.3460G>A, m.11778G>A, and m.14484T>C account for over 90% of LHON cases, and in DOA, the majority of affected families harbour mutations in the OPA1 gene, which codes for a mitochondrial inner membrane protein. Optic nerve degeneration in LHON and DOA is therefore due to disturbed mitochondrial function and a predominantly complex I respiratory chain defect has been identified using both in vitro and in vivo biochemical assays. However, the trigger for RGC loss is much more complex than a simple bioenergetic crisis and other important disease mechanisms have emerged relating to mitochondrial network dynamics, mtDNA maintenance, axonal transport, and the involvement of the cytoskeleton in maintaining a differential mitochondrial gradient at sites such as the lamina cribosa. The downstream consequences of these mitochondrial disturbances are likely to be influenced by the local cellular milieu. The vulnerability of RGCs in LHON and DOA could derive not only from tissue-specific, genetically-determined biological factors, but also from an increased susceptibility to exogenous influences such as light exposure, smoking, and pharmacological agents with putative mitochondrial toxic effects. Our concept of inherited mitochondrial optic neuropathies has evolved over the past decade, with the observation that patients with LHON and DOA can manifest a much broader phenotypic spectrum than pure optic nerve involvement. Interestingly, these phenotypes are sometimes clinically indistinguishable from other neurodegenerative disorders such as Charcot-Marie-Tooth disease, hereditary spastic paraplegia, and multiple sclerosis, where mitochondrial dysfunction is also thought to be an important pathophysiological player. A number of vertebrate and invertebrate disease models has recently been established to circumvent the lack of human tissues, and these have already provided considerable insight by allowing direct RGC experimentation. The ultimate goal is to translate these research advances into clinical practice and new treatment strategies are currently being investigated to improve the visual prognosis for patients with mitochondrial optic neuropathies.
Collapse
MESH Headings
- Animals
- DNA, Mitochondrial/genetics
- Disease Models, Animal
- Humans
- Optic Atrophy, Autosomal Dominant/pathology
- Optic Atrophy, Autosomal Dominant/physiopathology
- Optic Atrophy, Autosomal Dominant/therapy
- Optic Atrophy, Hereditary, Leber/pathology
- Optic Atrophy, Hereditary, Leber/physiopathology
- Optic Atrophy, Hereditary, Leber/therapy
- Optic Nerve/pathology
- Phenotype
- Point Mutation
- Retinal Ganglion Cells/pathology
Collapse
Affiliation(s)
- Patrick Yu-Wai-Man
- Mitochondrial Research Group, Institute for Ageing and Health, The Medical School, Newcastle University, UK.
| | | | | |
Collapse
|
43
|
Hudson G, Yu-Wai-Man P, Griffiths PG, Caporali L, Salomao SS, Berezovsky A, Carelli V, Zeviani M, Chinnery PF. Variation in OPA1 does not explain the incomplete penetrance of Leber hereditary optic neuropathy. Mol Vis 2010; 16:2760-4. [PMID: 21203403 PMCID: PMC3012648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 12/11/2010] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Leber hereditary optic neuropathy (LHON) is a common cause of inherited blindness, primarily due to one of three mitochondrial DNA (mtDNA) mutations. These mtDNA pathogenic mutations have variable clinical penetrance. Recent linkage evidence raised the possibility that the nuclear gene optic atrophy 1 (OPA1) determines whether mtDNA mutation carriers develop blindness. To validate these findings we studied OPA1 in three independent LHON cohorts: sequencing the gene in discordant male sib pairs, carrying out a family-based association study of common functional genetic variants, and carrying out a population-based association study of the same genetic variants. METHODS We tested 3 hypothesis in three separate study groups. Study group 1: Direct sequencing of OPA1 coding regions was performed using sequencing methodologies (Applied Biosystems, Foster City, CA). Chromatograms were compared with the GenBank reference sequence NM_015560.1. Splice-site prediction was performed using GeneSplicer. Study group 2: Genotyping for rs166850 and rs10451941 was performed by restriction fragment length polymorphism (RFLP) analysis with specific primers for both genotypes, using The restriction enzymes RsaI and FspBI to discriminate genotypes. Study group 3: Genotyping for rs166850 and rs10451941 was performed by primer extension of allele-specific extensions products by matrix-associated laser desorption/ionisation time-of-flight (MALDI-TOF, Seqeunom, San Diego, CA) mass spectrometry. Allele and genotype frequencies were compared using Pearson's chi-square test. Multiple logistic regression was performed to look for interactions between the variables. All analyses were performed using SPSS software version 17.0 (SPSS Inc.). RESULTS In all three groups we were unable to find an association between OPA1 genetic variation and visual failure in LHON mtDNA mutation carriers. CONCLUSIONS Our findings suggest that genetic variation in OPA1 is unlikely to make a major contribution to the risk of blindness in LHON mutation carriers.
Collapse
Affiliation(s)
- Gavin Hudson
- Institute for Human Genetics, Newcastle University, Newcastle upon Tyne, UK
| | - Patrick Yu-Wai-Man
- Institute for Human Genetics, Newcastle University, Newcastle upon Tyne, UK
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | | | - Leonardo Caporali
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
| | - Solange S. Salomao
- Departamento de Oftalmologia, Universidade Federal de Sao Paulo, UNIFESP, Sao Paulo, Brazil
| | - Adriana Berezovsky
- Departamento de Oftalmologia, Universidade Federal de Sao Paulo, UNIFESP, Sao Paulo, Brazil
| | - Valerio Carelli
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
| | - Massimo Zeviani
- Foundation Neurological Institue C. Besta, Unit of Molecular Neurogenetics, Milan, Italy
| | | |
Collapse
|
44
|
Abstract
Glaucoma, a leading cause of blindness worldwide, is characterized by progressive optic nerve damage, usually associated with intraocular pressure. Although the clinical progression of the disease is well defined, the molecular events responsible for glaucoma are currently poorly understood and current therapeutic strategies are not curative. This review summarizes the human genetics and genomic approaches that have shed light on the complex inheritance of glaucoma genes and the potential for gene-based and cellular therapies that this research makes possible.
Collapse
Affiliation(s)
- Bao Jian Fan
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | | |
Collapse
|
45
|
Barboni P, Carbonelli M, Savini G, Foscarini B, Parisi V, Valentino ML, Carta A, Negri AD, Sadun F, Zeviani M, Sadun AA, Schimpf S, Wissinger B, Carelli V. OPA1 Mutations Associated with Dominant Optic Atrophy Influence Optic Nerve Head Size. Ophthalmology 2010; 117:1547-53. [DOI: 10.1016/j.ophtha.2009.12.042] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 12/28/2009] [Accepted: 12/29/2009] [Indexed: 10/19/2022] Open
|