1
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Giordano L, Deceglie S, d'Adamo P, Valentino ML, La Morgia C, Fracasso F, Roberti M, Cappellari M, Petrosillo G, Ciaravolo S, Parente D, Giordano C, Maresca A, Iommarini L, Del Dotto V, Ghelli AM, Salomao SR, Berezovsky A, Belfort R, Sadun AA, Carelli V, Loguercio Polosa P, Cantatore P. Cigarette toxicity triggers Leber's hereditary optic neuropathy by affecting mtDNA copy number, oxidative phosphorylation and ROS detoxification pathways. Cell Death Dis 2015; 6:e2021. [PMID: 26673666 PMCID: PMC4720897 DOI: 10.1038/cddis.2015.364] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 01/15/2023]
Abstract
Leber's hereditary optic neuropathy (LHON), the most frequent mitochondrial disease, is associated with mitochondrial DNA (mtDNA) point mutations affecting Complex I subunits, usually homoplasmic. This blinding disorder is characterized by incomplete penetrance, possibly related to several genetic modifying factors. We recently reported that increased mitochondrial biogenesis in unaffected mutation carriers is a compensatory mechanism, which reduces penetrance. Also, environmental factors such as cigarette smoking have been implicated as disease triggers. To investigate this issue further, we first assessed the relationship between cigarette smoke and mtDNA copy number in blood cells from large cohorts of LHON families, finding that smoking was significantly associated with the lowest mtDNA content in affected individuals. To unwrap the mechanism of tobacco toxicity in LHON, we exposed fibroblasts from affected individuals, unaffected mutation carriers and controls to cigarette smoke condensate (CSC). CSC decreased mtDNA copy number in all cells; moreover, it caused significant reduction of ATP level only in mutated cells including carriers. This implies that the bioenergetic compensation in carriers is hampered by exposure to smoke derivatives. We also observed that in untreated cells the level of carbonylated proteins was highest in affected individuals, whereas the level of several detoxifying enzymes was highest in carriers. Thus, carriers are particularly successful in reactive oxygen species (ROS) scavenging capacity. After CSC exposure, the amount of detoxifying enzymes increased in all cells, but carbonylated proteins increased only in LHON mutant cells, mostly from affected individuals. All considered, it appears that exposure to smoke derivatives has a more deleterious effect in affected individuals, whereas carriers are the most efficient in mitigating ROS rather than recovering bioenergetics. Therefore, the identification of genetic modifiers that modulate LHON penetrance must take into account also the exposure to environmental triggers such as tobacco smoke.
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MESH Headings
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/metabolism
- Female
- Humans
- Male
- Optic Atrophy, Hereditary, Leber/etiology
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/metabolism
- Optic Atrophy, Hereditary, Leber/pathology
- Oxidative Phosphorylation
- Reactive Oxygen Species/metabolism
- Smoking/adverse effects
- Smoking/genetics
- Smoking/metabolism
- Smoking/pathology
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Affiliation(s)
- L Giordano
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - S Deceglie
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - P d'Adamo
- Department of Reproductive Sciences, Medical Genetics, Development and Public Health, University of Trieste, Trieste, Italy
- IRCCS-Burlo Garofolo Children Hospital, Trieste, Italy
| | - M L Valentino
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), Neurology Unit, University of Bologna, Bologna, Italy
| | - C La Morgia
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), Neurology Unit, University of Bologna, Bologna, Italy
| | - F Fracasso
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - M Roberti
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - M Cappellari
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - G Petrosillo
- Institute of Biomembranes and Bioenergetics (IBBE) National Research Council (CNR), Bari, Italy
| | - S Ciaravolo
- Vectis s.r.l. Cava dei Tirreni (Salerno), Italy
| | - D Parente
- Vectis s.r.l. Cava dei Tirreni (Salerno), Italy
| | - C Giordano
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Rome, Italy
| | - A Maresca
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), Neurology Unit, University of Bologna, Bologna, Italy
| | - L Iommarini
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), Neurology Unit, University of Bologna, Bologna, Italy
| | - V Del Dotto
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - A M Ghelli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - S R Salomao
- Department of Ophthalmology, and Visual Sciences, Paulista School of Medicine Federal University of Sao Paulo—UNIFESP, Sao Paulo, Brazil
| | - A Berezovsky
- Department of Ophthalmology, and Visual Sciences, Paulista School of Medicine Federal University of Sao Paulo—UNIFESP, Sao Paulo, Brazil
| | - R Belfort
- Department of Ophthalmology, and Visual Sciences, Paulista School of Medicine Federal University of Sao Paulo—UNIFESP, Sao Paulo, Brazil
| | - A A Sadun
- Doheny Eye Institute, University of California Los Angeles (UCLA), Los Angeles, CA, USA
| | - V Carelli
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), Neurology Unit, University of Bologna, Bologna, Italy
| | - P Loguercio Polosa
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - P Cantatore
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
- Institute of Biomembranes and Bioenergetics (IBBE) National Research Council (CNR), Bari, Italy
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Carelli V, d'Adamo P, Valentino ML, La Morgia C, Ross-Cisneros FN, Caporali L, Maresca A, Loguercio Polosa P, Barboni P, De Negri A, Sadun F, Karanjia R, Salomao SR, Berezovsky A, Chicani F, Moraes M, Moraes Filho M, Belfort R, Sadun AA. Parsing the differences in affected with LHON: genetic versus environmental triggers of disease conversion. Brain 2015; 139:e17. [PMID: 26657166 DOI: 10.1093/brain/awv339] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Valerio Carelli
- 1 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy 2 Neurology Unit, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Pio d'Adamo
- 3 Medical Genetics, Department of Reproductive Sciences, Development and Public Health, University of Trieste, Trieste, Italy 4 IRCCS-Burlo Garofolo Children Hospital, Trieste, Italy
| | - Maria Lucia Valentino
- 1 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy 2 Neurology Unit, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- 1 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy 2 Neurology Unit, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | | | - Leonardo Caporali
- 1 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
| | - Alessandra Maresca
- 1 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy 2 Neurology Unit, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Paola Loguercio Polosa
- 6 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Piero Barboni
- 7 IRCCS Istituto Scientifico San Raffaele, Milan, Italy
| | | | | | - Rustum Karanjia
- 10 Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Solange R Salomao
- 11 Department of Ophthalmology, Federal University of Sao Paulo (UNIFESP) and IPEPO (Instituto da Visão), Sao Paulo, Brazil
| | - Adriana Berezovsky
- 11 Department of Ophthalmology, Federal University of Sao Paulo (UNIFESP) and IPEPO (Instituto da Visão), Sao Paulo, Brazil
| | - Filipe Chicani
- 11 Department of Ophthalmology, Federal University of Sao Paulo (UNIFESP) and IPEPO (Instituto da Visão), Sao Paulo, Brazil
| | | | | | - Rubens Belfort
- 11 Department of Ophthalmology, Federal University of Sao Paulo (UNIFESP) and IPEPO (Instituto da Visão), Sao Paulo, Brazil
| | - Alfredo A Sadun
- 5 Doheny Eye Institute, Los Angeles, CA, USA 10 Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA
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Carbonelli M, La Morgia C, Savini G, Cascavilla ML, Borrelli E, Chicani F, do V. F. Ramos C, Salomao SR, Parisi V, Sebag J, Bandello F, Sadun AA, Carelli V, Barboni P. Macular Microcysts in Mitochondrial Optic Neuropathies: Prevalence and Retinal Layer Thickness Measurements. PLoS One 2015; 10:e0127906. [PMID: 26047507 PMCID: PMC4457906 DOI: 10.1371/journal.pone.0127906] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 04/20/2015] [Indexed: 01/10/2023] Open
Abstract
PURPOSE To investigate the thickness of the retinal layers and to assess the prevalence of macular microcysts (MM) in the inner nuclear layer (INL) of patients with mitochondrial optic neuropathies (MON). METHODS All patients with molecularly confirmed MON, i.e. Leber's Hereditary Optic Neuropathy (LHON) and Dominant Optic Atrophy (DOA), referred between 2010 and 2012 were enrolled. Eight patients with MM were compared with two control groups: MON patients without MM matched by age, peripapillary retinal nerve fiber layer (RNFL) thickness, and visual acuity, as well as age-matched controls. Retinal segmentation was performed using specific Optical coherence tomography (OCT) software (Carl Zeiss Meditec). Macular segmentation thickness values of the three groups were compared by one-way analysis of variance with Bonferroni post hoc corrections. RESULTS MM were identified in 5/90 (5.6%) patients with LHON and 3/58 (5.2%) with DOA. The INL was thicker in patients with MON compared to controls regardless of the presence of MM [133.1±7μm vs 122.3±9μm in MM patients (p<0.01) and 128.5±8μm vs. 122.3±9μm in no-MM patients (p<0.05)], however the outer nuclear layer (ONL) was thicker in patients with MM (101.4±1mμ) compared to patients without MM [77.5±8mμ (p<0.001)] and controls [78.4±7mμ (p<0.001)]. ONL thickness did not significantly differ between patients without MM and controls. CONCLUSION The prevalence of MM in MON is low (5-6%), but associated with ONL thickening. We speculate that in MON patients with MM, vitreo-retinal traction contributes to the thickening of ONL as well as to the production of cystic spaces.
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Affiliation(s)
- Michele Carbonelli
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
| | - Chiara La Morgia
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
- Neurology Unit, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | | | | | | | - Filipe Chicani
- Department of Ophthalmology, Federal University of São Paulo, UNIFESP, São Paulo, Brazil
| | | | - Solange R. Salomao
- Department of Ophthalmology, Federal University of São Paulo, UNIFESP, São Paulo, Brazil
| | | | - Jerry Sebag
- Doheny Eye Institute, Los Angeles, University of California Los Angeles, Los Angeles, California, United States of America
- VMR Institute for Vitreous Macula Retina, Huntington Beach, California, United States of America
| | | | - Alfredo A. Sadun
- Doheny Eye Institute, Los Angeles, University of California Los Angeles, Los Angeles, California, United States of America
| | - Valerio Carelli
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
- Neurology Unit, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Piero Barboni
- San Raffaele Scientific Institute, Milan, Italy
- Studio Oculistico d’Azeglio, Bologna, Italy
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4
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Mitsuhiro MH, Berezovsky A, Belfort R, Ellwein LB, Salomao SR. Uptake, Barriers and Outcomes in the Follow-up of Patients Referred for Free-of-Cost Cataract Surgery in the Sao Paulo Eye Study. Ophthalmic Epidemiol 2014; 22:253-9. [PMID: 25310584 DOI: 10.3109/09286586.2014.966849] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE To determine uptake, barriers and outcomes in the follow-up of patients referred for free-of-charge, expedited cataract surgery in the Sao Paulo Eye Study (SPES). METHODS SPES was a population-based study of urban, low-middle income residents aged ≥50 years. Presenting visual acuity (PVA), best-corrected visual acuity, refraction, and slit-lamp examination were performed in 3677 participants. For subjects with cataract as a principal cause of best-corrected visual acuity ≤20/40, surgery was offered free of charge. Two years after the baseline study, surgery uptake, barriers to surgery, and visual outcomes were analyzed. RESULTS Among 210 (5.71%) participants who had a cataract surgery indication at baseline, 164 (78.1%) were successfully contacted and 55 (33.5%) reported being operated on for cataract, with 51 agreeing to be re-examined. In a multiple logistic regression model, age, sex, schooling, previous cataract surgery, and PVA at baseline were not significantly associated with surgery uptake. Co-existing health conditions (20.4%), fear of surgery (12.2%) and fear of losing eyesight (11.6%) were the most frequent barriers to cataract surgery adherence. Among the 69 eyes operated on in the interval between baseline and follow-up, PVA ≥20/63 was observed in 50 (72.6%, 95% confidence interval, CI, 62.2-82.3%), PVA <20/63-20/200 in 11 (15.8%, 95% CI 8.9-22.9%) and PVA <20/200 in 8 (11.6%, 95% CI 5.3-17.9%). CONCLUSIONS Quality of surgery is an increasing determinant of uptake rates. Although free-of-charge and expedited cataract surgery was offered, surgical outcomes might have influenced the low uptake. Aside from cataract surgery campaigns, improvement of surgeon skills, accurate biometry, treatment of ocular comorbidities, postoperative follow-up and eye-care education are needed.
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Affiliation(s)
- Marcia H Mitsuhiro
- Departamento de Oftalmologia, Escola Paulista de Medicina, Universidade Federal de Sao Paulo , Sao Paulo, SP , Brasil and
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Giordano C, Iommarini L, Giordano L, Maresca A, Pisano A, Valentino ML, Caporali L, Liguori R, Deceglie S, Roberti M, Fanelli F, Fracasso F, Ross-Cisneros FN, D’Adamo P, Hudson G, Pyle A, Yu-Wai-Man P, Chinnery PF, Zeviani M, Salomao SR, Berezovsky A, Belfort R, Ventura DF, Moraes M, Moraes Filho M, Barboni P, Sadun F, De Negri A, Sadun AA, Tancredi A, Mancini M, d’Amati G, Loguercio Polosa P, Cantatore P, Carelli V. Efficient mitochondrial biogenesis drives incomplete penetrance in Leber's hereditary optic neuropathy. Brain 2014; 137:335-53. [PMID: 24369379 PMCID: PMC3914475 DOI: 10.1093/brain/awt343] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 09/06/2013] [Accepted: 10/21/2013] [Indexed: 12/16/2022] Open
Abstract
Leber's hereditary optic neuropathy is a maternally inherited blinding disease caused as a result of homoplasmic point mutations in complex I subunit genes of mitochondrial DNA. It is characterized by incomplete penetrance, as only some mutation carriers become affected. Thus, the mitochondrial DNA mutation is necessary but not sufficient to cause optic neuropathy. Environmental triggers and genetic modifying factors have been considered to explain its variable penetrance. We measured the mitochondrial DNA copy number and mitochondrial mass indicators in blood cells from affected and carrier individuals, screening three large pedigrees and 39 independently collected smaller families with Leber's hereditary optic neuropathy, as well as muscle biopsies and cells isolated by laser capturing from post-mortem specimens of retina and optic nerves, the latter being the disease targets. We show that unaffected mutation carriers have a significantly higher mitochondrial DNA copy number and mitochondrial mass compared with their affected relatives and control individuals. Comparative studies of fibroblasts from affected, carriers and controls, under different paradigms of metabolic demand, show that carriers display the highest capacity for activating mitochondrial biogenesis. Therefore we postulate that the increased mitochondrial biogenesis in carriers may overcome some of the pathogenic effect of mitochondrial DNA mutations. Screening of a few selected genetic variants in candidate genes involved in mitochondrial biogenesis failed to reveal any significant association. Our study provides a valuable mechanism to explain variability of penetrance in Leber's hereditary optic neuropathy and clues for high throughput genetic screening to identify the nuclear modifying gene(s), opening an avenue to develop predictive genetic tests on disease risk and therapeutic strategies.
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Affiliation(s)
- Carla Giordano
- 1 Department of Radiology, Oncology and Pathology, Sapienza, University of Rome, Rome, Italy
| | - Luisa Iommarini
- 2 Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Luca Giordano
- 3 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Alessandra Maresca
- 2 Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- 4 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
| | - Annalinda Pisano
- 1 Department of Radiology, Oncology and Pathology, Sapienza, University of Rome, Rome, Italy
| | - Maria Lucia Valentino
- 2 Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- 4 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
| | - Leonardo Caporali
- 2 Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- 4 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
| | - Rocco Liguori
- 2 Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- 4 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
| | - Stefania Deceglie
- 3 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Marina Roberti
- 3 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Francesca Fanelli
- 3 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Flavio Fracasso
- 3 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Fred N. Ross-Cisneros
- 5 Departments of Ophthalmology and Neurosurgery, Keck School of Medicine at USC, Los Angeles, CA, USA
| | - Pio D’Adamo
- 6 Medical Genetics, Department of Reproductive Sciences, Development and Public Health
- 7 IRCCS-Burlo Garofolo Children Hospital, University of Trieste, Trieste, Italy
| | - Gavin Hudson
- 8 Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Angela Pyle
- 8 Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Patrick Yu-Wai-Man
- 8 Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Patrick F. Chinnery
- 8 Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Massimo Zeviani
- 9 Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico “Carlo Besta” - IRCCS, Milano, Italy
- 10 MRC-Mitochondrial Biology Unit, Cambridge, UK
| | - Solange R. Salomao
- 11 Department of Ophthalmology, Federal University of Sao Paulo – UNIFESP, Sao Paulo, Brazil
| | - Adriana Berezovsky
- 11 Department of Ophthalmology, Federal University of Sao Paulo – UNIFESP, Sao Paulo, Brazil
| | - Rubens Belfort
- 11 Department of Ophthalmology, Federal University of Sao Paulo – UNIFESP, Sao Paulo, Brazil
| | - Dora Fix Ventura
- 12 Department of Experimental Psychology, Institute of Psychology, University of Sao Paulo, Sao Paulo, Brazil
| | - Milton Moraes
- 11 Department of Ophthalmology, Federal University of Sao Paulo – UNIFESP, Sao Paulo, Brazil
| | - Milton Moraes Filho
- 11 Department of Ophthalmology, Federal University of Sao Paulo – UNIFESP, Sao Paulo, Brazil
| | | | | | | | - Alfredo A. Sadun
- 5 Departments of Ophthalmology and Neurosurgery, Keck School of Medicine at USC, Los Angeles, CA, USA
| | - Andrea Tancredi
- 16 Dipartimento di Metodi e Modelli per l’Economia la Finanza e il Territorio, Sapienza, Università di Roma, Roma, Italy
| | - Massimiliano Mancini
- 1 Department of Radiology, Oncology and Pathology, Sapienza, University of Rome, Rome, Italy
- 17 Department of Molecular Medicine, Sapienza, University of Rome
| | - Giulia d’Amati
- 1 Department of Radiology, Oncology and Pathology, Sapienza, University of Rome, Rome, Italy
| | - Paola Loguercio Polosa
- 3 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Palmiro Cantatore
- 3 Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Valerio Carelli
- 2 Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- 4 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Bologna, Italy
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Pan BX, Ross-Cisneros FN, Carelli V, Rue KS, Salomao SR, Moraes-Filho MN, Moraes MN, Berezovsky A, Belfort R, Sadun AA. Mathematically modeling the involvement of axons in Leber's hereditary optic neuropathy. Invest Ophthalmol Vis Sci 2012; 53:7608-17. [PMID: 23060142 DOI: 10.1167/iovs.12-10452] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Leber's hereditary optic neuropathy (LHON), a mitochondrial disease, has clinical manifestations that reflect the initial preferential involvement of the papillomacular bundle (PMB). The present study seeks to predict the order of axonal loss in LHON optic nerves using the Nerve Fiber Layer Stress Index (NFL-S(I)), which is a novel mathematical model. METHODS Optic nerves were obtained postmortem from four molecularly characterized LHON patients with varying degrees of neurodegenerative changes and three age-matched controls. Tissues were cut in cross-section and stained with p-phenylenediamine to visualize myelin. Light microscopic images were captured in 32 regions of each optic nerve. Control and LHON tissues were evaluated by measuring axonal dimensions to generate an axonal diameter distribution map. LHON tissues were further evaluated by determining regions of total axonal depletion. RESULTS A size gradient was evident in the control optic nerves, with average axonal diameter increasing progressively from the temporal to nasal borders. LHON optic nerves showed an orderly loss of axons, starting inferotemporally, progressing centrally, and sparing the superonasal region until the end. Values generated from the NFL-S(I) equation fit a linear regression curve (R(2) = 0.97; P < 0.001). CONCLUSIONS The quantitative histopathologic data from this study revealed that the PMB is most susceptible in LHON, supporting clinical findings seen early in the course of disease onset. The present study also showed that the subsequent progression of axonal loss within the optic nerve can be predicted precisely with the NFL-S(I) equation. The results presented provided further insight into the pathophysiology of LHON.
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Affiliation(s)
- Billy X Pan
- Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
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7
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Yee KM, Ross-Cisneros FN, Lee JG, Da Rosa AB, Salomao SR, Berezovsky A, Belfort R, Chicani F, Moraes-Filho M, Sebag J, Carelli V, Sadun AA. Neuron-specific enolase is elevated in asymptomatic carriers of Leber's hereditary optic neuropathy. Invest Ophthalmol Vis Sci 2012; 53:6389-92. [PMID: 22893673 DOI: 10.1167/iovs.12-9677] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Neuron-specific enolase (NSE) is a biomarker for neuronal stress. Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease affecting retinal ganglion cells (RGC). These RGCs and their axons in the retinal nerve fiber layer (RNFL) and optic nerve head may show subclinical pathology in unaffected mutation carriers, or undergo cell death in affected patients. We hypothesize that increased levels of blood NSE may characterize LHON carriers as a biomarker of ongoing RGC stress. METHODS Serum was obtained from 74 members of a Brazilian pedigree with LHON carrying the homoplasmic 11778/ND4 mitochondrial DNA mutation. Classified by symptoms and psychophysical metrics, 46/74 patients were unaffected mutation "carriers," 14/74 were "affected," and 14/74 were "off-pedigree" controls. Serum NSE levels were determined by ELISA specific for the γ subunit of NSE. RESULTS Serum NSE concentrations in carriers (27.17 ± 39.82 μg/L) were significantly higher than affected (5.66 ± 4.19 μg/L; P = 0.050) and off-pedigree controls (6.20 ± 2.35 μg/L; P = 0.047). Of the 14/46 (30.4 %) carriers with significantly elevated NSE levels (mean = 75.8 ± 42.3 μg/L), 9/14 (64.3%) were male. Furthermore, NSE levels were nearly three times greater in asymptomatic male carriers (40.65 ± 51.21 μg/L) than in asymptomatic female carriers (15.85 ± 22.27 μg/L; P = 0.034). CONCLUSIONS Serum NSE levels are higher in LHON carriers compared with affected and off-pedigree individuals. A subgroup of mostly male carriers had significantly elevated serum NSE levels. Thus, male carriers are at higher risk for LHON-related neuronal stress.
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Affiliation(s)
- Kenneth M Yee
- Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
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Caporali L, Giordano C, Iommarini L, Maresca A, D'adamo P, Salomao SR, Belfort R, Sadun A, Carelli V. Searching for genetic modifiers of Leber's hereditary optic neuropathy penetrance. Mitochondrion 2012. [DOI: 10.1016/j.mito.2012.07.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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La Morgia C, Ross-Cisneros FN, Sadun AA, Hannibal J, Munarini A, Mantovani V, Barboni P, Cantalupo G, Tozer KR, Sancisi E, Salomao SR, Moraes MN, Moraes-Filho MN, Heegaard S, Milea D, Kjer P, Montagna P, Carelli V. Melanopsin retinal ganglion cells are resistant to neurodegeneration in mitochondrial optic neuropathies. ACTA ACUST UNITED AC 2010; 133:2426-38. [PMID: 20659957 DOI: 10.1093/brain/awq155] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Mitochondrial optic neuropathies, that is, Leber hereditary optic neuropathy and dominant optic atrophy, selectively affect retinal ganglion cells, causing visual loss with relatively preserved pupillary light reflex. The mammalian eye contains a light detection system based on a subset of retinal ganglion cells containing the photopigment melanopsin. These cells give origin to the retinohypothalamic tract and support the non-image-forming visual functions of the eye, which include the photoentrainment of circadian rhythms, light-induced suppression of melatonin secretion and pupillary light reflex. We studied the integrity of the retinohypothalamic tract in five patients with Leber hereditary optic neuropathy, in four with dominant optic atrophy and in nine controls by testing the light-induced suppression of nocturnal melatonin secretion. This response was maintained in optic neuropathy subjects as in controls, indicating that the retinohypothalamic tract is sufficiently preserved to drive light information detected by melanopsin retinal ganglion cells. We then investigated the histology of post-mortem eyes from two patients with Leber hereditary optic neuropathy and one case with dominant optic atrophy, compared with three age-matched controls. On these retinas, melanopsin retinal ganglion cells were characterized by immunohistochemistry and their number and distribution evaluated by a new protocol. In control retinas, we show that melanopsin retinal ganglion cells are lost with age and are more represented in the parafoveal region. In patients, we demonstrate a relative sparing of these cells compared with the massive loss of total retinal ganglion cells, even in the most affected areas of the retina. Our results demonstrate that melanopsin retinal ganglion cells resist neurodegeneration due to mitochondrial dysfunction and maintain non-image-forming functions of the eye in these visually impaired patients. We also show that in normal human retinas, these cells are more concentrated around the fovea and are lost with ageing. The current results provide a plausible explanation for the preservation of pupillary light reaction despite profound visual loss in patients with mitochondrial optic neuropathy, revealing the robustness of melanopsin retinal ganglion cells to a metabolic insult and opening the question of mechanisms that might protect these cells.
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Affiliation(s)
- Chiara La Morgia
- Department of Neurological Sciences, University of Bologna, Bologna, Italy
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Barboni P, Carbonelli M, Savini G, Ramos CDVF, Carta A, Berezovsky A, Salomao SR, Carelli V, Sadun AA. Natural history of Leber's hereditary optic neuropathy: longitudinal analysis of the retinal nerve fiber layer by optical coherence tomography. Ophthalmology 2010; 117:623-7. [PMID: 20031228 DOI: 10.1016/j.ophtha.2009.07.026] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Revised: 07/09/2009] [Accepted: 07/21/2009] [Indexed: 02/03/2023] Open
Abstract
PURPOSE To investigate by optical coherence tomography (OCT) the topographic pattern and temporal sequence of fiber loss in the peripapillary retinal nerve fiber layer (RNFL) of patients with Leber's hereditary optic neuropathy (LHON) in a longitudinal follow-up. DESIGN Cohort study. PARTICIPANTS Six eyes of 4 patients with molecularly defined LHON were enrolled before the subacute period of visual loss. METHODS Subjects were studied by StratusOCT (Carl Zeiss Meditec, Inc., Dublin, CA) during a 9-month follow-up starting from the presymptomatic stage of the disease. Examinations were carried out at 4 different time points: presymptomatic stage, time of visual loss, and 3 and 9 months later. MAIN OUTCOME MEASURES Peripapillary RNFL thickness for each quadrant of the optic nerve. Statistical comparisons were performed by ordinary analysis of variance with Dunnett's post-test. RESULTS A significant increase of RNFL thickness was detected in the temporal and inferior quadrants between the presymptomatic stage and the disease onset (P<0.05). The 360-degree average and the superior and nasal quadrants showed a nonstatistically significant increase of thickness at this time. In the 360-degree average (P<0.01), superior (P<0.01), nasal (P<0.05), and inferior (P<0.01) quadrants, RNFL thickening showed statistically significant changes between the presymptomatic stage and the 3-month follow-up. At 3 months, a nonsignificant reduction of RNFL thickness was detected in the temporal quadrant. A significant reduction of RNFL was detected in all but the nasal quadrants between the presymptomatic stage and the 9-month Follow-up. CONCLUSIONS The RNFL thickness increase first appeared at the temporal and inferior quadrants. Conversely, at 3 months the thickening fibers were more evident in the superior and nasal quadrants. These findings are consistent with the established preferential early involvement of the papillomacular bundle in LHON. We also demonstrated the previously unrecognized simultaneous early involvement of the inferior quadrant. The late involvement of both superior and nasal quadrants suggests a dynamic evolution of the acute stage that continues for 3 months and may represent a therapeutic window of opportunity.
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Ramos CDVF, Bellusci C, Savini G, Carbonelli M, Berezovsky A, Tamaki C, Cinoto R, Sacai PY, Moraes-Filho MN, Miura HMPP, Valentino ML, Iommarini L, De Negri AM, Sadun F, Cortelli P, Montagna P, Salomao SR, Sadun AA, Carelli V, Barboni P. Association of Optic Disc Size with Development and Prognosis of Leber’s Hereditary Optic Neuropathy. ACTA ACUST UNITED AC 2009; 50:1666-74. [DOI: 10.1167/iovs.08-2695] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Carolina do V. F. Ramos
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | | | - Giacomo Savini
- Fondazione G. B. Bietti-IRCCS (Istituto Ricerca e Cura a Carattere Scientifico), Roma, Italy
| | | | - Adriana Berezovsky
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | - Celina Tamaki
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | - Rafael Cinoto
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | - Paula Y. Sacai
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | - Milton N. Moraes-Filho
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | - Hevillin M. P. P. Miura
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | | | - Luisa Iommarini
- Fondazione G. B. Bietti-IRCCS (Istituto Ricerca e Cura a Carattere Scientifico), Roma, Italy
| | | | | | - Pietro Cortelli
- Dipartimento di Scienze Neurologiche, Universita` di Bologna, Bologna, Italy
| | - Pasquale Montagna
- Dipartimento di Scienze Neurologiche, Universita` di Bologna, Bologna, Italy
| | - Solange R. Salomao
- From the Department of Ophthalmology, Federal University of Sa~o Paulo (UNIFESP), Sa~o Paulo, Brazil
| | - Alfredo A. Sadun
- Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine of the University of the Southern California, Los Angeles, California
| | - Valerio Carelli
- Dipartimento di Scienze Neurologiche, Universita` di Bologna, Bologna, Italy
| | - Piero Barboni
- Studio Oculistico d’Azeglio, Bologna, Italy;5Dipartimento di Scienze Neurologiche, Universita` di Bologna, Bologna, Italy
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Guy J, Shaw G, Ross-Cisneros FN, Quiros P, Salomao SR, Berezovsky A, Carelli V, Feuer WJ, Sadun AA. Phosphorylated neurofilament heavy chain is a marker of neurodegeneration in Leber hereditary optic neuropathy (LHON). Mol Vis 2008; 14:2443-50. [PMID: 19104679 PMCID: PMC2605731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Accepted: 12/09/2008] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To determine the profile of neurodegeneration in Leber hereditary optic neuropathy (LHON). METHODS We quantitated serum levels of phosphorylated neurofilament heavy chain (pNF-H) in a Brazilian pedigree of 16 affected patients and 59 carriers with LHON, both molecularly characterized as harboring the G to A mutation at nucleotide 11,778 of the mitochondrial genome. The association of subject characteristics to pNF-H levels was studied with multiple regression; pNF-H data were square-root transformed to effect normality of distribution of residuals. Relationships between the square-root of pNF-H and age and sex were investigated within groups with Pearson correlation and the two-sample t-test. Linear regression was used to assess the difference between groups and to determine if the relationship of age was different between affected individuals and carriers. Results of plotting pNF-H levels by age suggested a nonlinear, quadratic association so age squared was used in the statistical analysis. ANCOVA was used to assess the influence of age and group on pNF-H levels. RESULTS In the carrier group, there was a significant correlation of square-root pNF-H (mean=0.24 ng/ml(2)) with age (r=0.30, p=0.022) and a stronger correlation with quadratic age (r=0.37, p=0.003). With a higher mean pNF-H (0.33 ng/ml(2)) for the affected group, correlations were of similar magnitude, although they were not statistically significant: age (r=0.22, p=0.42), quadratic age (r=0.22, p=0.45). There was no correlation between age and pNF-H levels (mean=0.34 ng/ml(2)) in the off-pedigree group: age (r=0.03, p=0.87), quadratic age (r=0.04, p=0.84). There was no difference between sexes and pNF-H levels in any of the groups (affected, p=0.65; carriers, p=0.19; off-pedigree, p=0.93). CONCLUSIONS Elevated pNF-H released into the serum of some affected LHON patients may suggest that axonal degeneration occurs at some point after loss of visual function. Increases in pNF-H levels of carriers with increasing age, not seen in off-pedigree controls, may suggest subtle subclinical optic nerve degeneration.
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Affiliation(s)
- John Guy
- Bascom Palmer Eye Institute, McKnight Vision Research Center, Miami, FL 33136, USA.
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Salomao SR, Cinoto RW, Berezovsky A, Araujo-Filho A, Mitsuhiro MRKH, Mendieta L, Morales PHA, Pokharel GP, Belfort R, Ellwein LB. Prevalence and causes of vision impairment and blindness in older adults in Brazil: the Sao Paulo Eye Study. Ophthalmic Epidemiol 2008; 15:167-75. [PMID: 18569812 DOI: 10.1080/09286580701843812] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE Investigate prevalence and causes of vision impairment/blindness in older adults in a low-middle income area of Sao Paulo, Brazil. METHODS Cluster sampling, based on geographically defined census sectors, was used in randomly selecting cross-sectionally persons 50 years of age or older. Subjects were enumerated through a door-to-door survey and invited for measurement of presenting and best-corrected visual acuity and an ocular examination. The principal cause was identified for eyes with presenting visual acuity less than 20/32. RESULTS A total of 4,224 eligible persons in 2,870 households were enumerated, and 3,678 (87.1%) examined. The prevalence of presenting visual acuity > or = 20/32 in both eyes was 61.6% (95% confidence interval [CI]: 59.4%-63.9%), and 80.4% (95% CI: 78.8%-82.1%) with best correction. The prevalence of visual impairment (< 20/63 to > or =20/200) in the better eye was 4.74% (95% CI: 3.97%-5.53%), and 2.00% (95% CI: 1.52%-2.49%) with best correction. The prevalence of presenting bilateral blindness (< 20/200) was 1.51% (95% CI: 1.20%-1.82%), and 1.07% (95% CI: 0.79%-1.35%) with best correction. Presenting blindness was associated with older age and lack of schooling. Retinal disorders (35.3%) and cataract (28.3%) were the most common causes of blind eyes. Cataract (33.2%), refractive error (32.3%), and retinal disorders (20.3%) were the main causes of vision impairment < 20/63 to > or = 20/200, with refractive error (76.8%) and cataract (12.2%) as main causes for eyes with acuity < 20/32 to > or = 20/63. CONCLUSIONS Vision impairment is a significant problem in older Brazilians reinforcing the need to implement prevention of blindness programs for elderly people with emphasis on those without schooling.
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Affiliation(s)
- Solange R Salomao
- Vision Institute, Department of Ophthalmology, Federal University of Sao Paulo (UNIFESP-Paulista School of Medicine), Sao Paulo, SP, Brazil.
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Shankar SP, Fingert JH, Carelli V, Valentino ML, King TM, Daiger SP, Salomao SR, Berezovsky A, Belfort R, Braun TA, Sheffield VC, Sadun AA, Stone EM. Evidence for a novel x-linked modifier locus for leber hereditary optic neuropathy. Ophthalmic Genet 2008; 29:17-24. [PMID: 18363168 DOI: 10.1080/13816810701867607] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Leber Hereditary Optic Neuropathy (LHON) is a maternally inherited blinding disease caused by missense mutations in the mitochondrial DNA (mtDNA). However, incomplete penetrance and a predominance of male patients presenting with vision loss suggest that modifying factors play an important role in the development of the disease. Evidence from several studies suggests that both nuclear modifier genes and environmental factors may be necessary to trigger the optic neuropathy in individuals harboring an LHON-causing mtDNA mutation. Recently, an optic neuropathy susceptibility locus at Xp21-Xq21 has been reported. In this study, we performed X-chromosomal linkage analysis in a large Brazilian family harboring a homoplasmic G11778A mtDNA mutation on a haplogroup J background. We report the identification of a novel LHON susceptibility locus on chromosome Xq25-27.2, with multipoint non-parametric linkage scores of > 5.00 (P = 0.005) and a maximum two-point non-parametric linkage score of 10.12, (P = 0.003) for marker DXS984 (Xq27.1). These results suggest genetic heterogeneity for X-linked modifiers of LHON.
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Affiliation(s)
- Suma P Shankar
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
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Hudson G, Carelli V, Spruijt L, Gerards M, Mowbray C, Achilli A, Pyle A, Elson J, Howell N, La Morgia C, Valentino ML, Huoponen K, Savontaus ML, Nikoskelainen E, Sadun AA, Salomao SR, Belfort R, Griffiths P, Yu-Wai-Man P, de Coo RFM, Horvath R, Zeviani M, Smeets HJT, Torroni A, Chinnery PF. Clinical expression of Leber hereditary optic neuropathy is affected by the mitochondrial DNA-haplogroup background. Am J Hum Genet 2007; 81:228-33. [PMID: 17668373 PMCID: PMC1950812 DOI: 10.1086/519394] [Citation(s) in RCA: 270] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Accepted: 04/24/2007] [Indexed: 12/16/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is due primarily to one of three common point mutations of mitochondrial DNA (mtDNA), but the incomplete penetrance implicates additional genetic or environmental factors in the pathophysiology of the disorder. Both the 11778G-->A and 14484T-->C LHON mutations are preferentially found on a specific mtDNA genetic background, but 3460G-->A is not. However, there is no clear evidence that any background influences clinical penetrance in any of these mutations. By studying 3,613 subjects from 159 LHON-affected pedigrees, we show that the risk of visual failure is greater when the 11778G-->A or 14484T-->C mutations are present in specific subgroups of haplogroup J (J2 for 11778G-->A and J1 for 14484T-->C) and when the 3460G-->A mutation is present in haplogroup K. By contrast, the risk of visual failure is significantly less when 11778G-->A occurs in haplogroup H. Substitutions on MTCYB provide an explanation for these findings, which demonstrate that common genetic variants have a marked effect on the expression of an ostensibly monogenic mtDNA disorder.
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Affiliation(s)
- Gavin Hudson
- Mitochondrial Research Group, Department of Ophthalmology and Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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Sadun AA, Salomao SR, Berezovsky A, Sadun F, Denegri AM, Quiros PA, Chicani F, Ventura D, Barboni P, Sherman J, Sutter E, Belfort R, Carelli V. Subclinical carriers and conversions in Leber hereditary optic neuropathy: a prospective psychophysical study. Trans Am Ophthalmol Soc 2006; 104:51-61. [PMID: 17471325 PMCID: PMC1809912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
PURPOSE The authors previously presented the results of their 2001 field investigation to rural Brazil to investigate a 336-member pedigree of Leber hereditary optic neuropathy (LHON). The present work describes the yearly field investigations 2001 to 2005, utilizing a variety of highly sophisticated psychophysical and electrophysiologic procedures, in asymptomatic LHON carriers, some of whom converted to affected status. METHODS Careful, repeated examinations of 75 carriers of homoplasmic 11778 LHON mtDNA J-haplogroup mutants were performed as part of the field investigation of this pedigree. All subjects underwent a detailed neuro-ophthalmologic investigation, including formal visual fields (Humphrey; HVF) and fundus photography. In addition, many subjects underwent rigorous psychophysical examination, including Cambridge Research Systems color vision and contrast sensitivity testing, OCT, GDx, and multifocal visual evoked response (mfVER) and multifocal electroretinogram (mfERG). Two patients followed as nonsymptomatic LHON carriers converted to affected status. RESULTS Many LHON carriers did, in fact, show subclinical or occult abnormalities. Focal edema was often seen involving the arcuate nerve fiber bundles, and this corresponded with areas of relative paracentral or arcuate scotomas on HVF testing. Compared to controls, LHON carriers had significant losses in color vision affecting mostly the red-green system and reduction in spatial but not temporal contrast sensitivity. The mfVER and mfERG data showed that most carriers had depressed central responses and abnormal interocular asymmetries. CONCLUSIONS In this very large pedigree of 11778 LHON, the carriers frequently showed manifestations of optic nerve impairments. Their occult disease reflected low-grade compromise that waxed and waned. In two cases, these changes led to a crescendo of dramatic impairments that characterize conversion to affected status.
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Affiliation(s)
- Alfredo A Sadun
- Keck-USC School of Medicine/Doheny Eye Institute, Los Angeles, California, USA
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Sadun F, De Negri AM, Carelli V, Salomao SR, Berezovsky A, Andrade R, Moraes M, Passos A, Belfort R, da Rosa AB, Quiros P, Sadun AA. Ophthalmologic findings in a large pedigree of 11778/Haplogroup J Leber hereditary optic neuropathy. Am J Ophthalmol 2004; 137:271-7. [PMID: 14962416 DOI: 10.1016/j.ajo.2003.08.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2003] [Indexed: 02/07/2023]
Abstract
PURPOSE To report the ophthalmologic characteristics of a newly identified seven-generation pedigree of 11778/Haplogroup J Leber hereditary optic neuropathy consisting of 328 living individuals, 111 of whom are maternally related. DESIGN Observational population cohort study. METHODS This prospective study of a large Brazilian Leber hereditary optic neuropathy pedigree was carried out as a field investigation in Brazil. We describe the ophthalmologic findings of 192 eyes from 96 maternally related individuals of this pedigree. Spouses were used as control subjects. We conducted comprehensive neuro-ophthalmologic examinations with psychophysical tests, Humphrey visual fields, and fundus photographs. We also correlated the ophthalmologic findings with the previously published epidemiologic assessment of risk factors. RESULTS We examined 76 carriers and 20 affected individuals. The affected individuals showed severe disease with a mean visual acuity of 2.04 logarithm of the minimal angle of resolution and without evidence of recovery. All the affected individuals showed diffuse optic atrophy with a cup-to-disk ratio greater than 0.5 in 55% of cases. Moreover, among Affected individuals, smokers had a poorer visual acuity (P =.002). Among carriers there were several subclinical abnormalities, including microangiopathy, swelling of nerve fibers, and visual field abnormalities that did not correlate with tobacco or alcohol consumption. CONCLUSIONS Our results demonstrate a significant influence of environmental risk factors, particularly smoking, for developing Leber hereditary optic neuropathy and for the severity of its clinical expression. However, smoking did not correlate with the subclinical abnormalities detected in carriers. Moreover, subclinical abnormalities were equally distributed between gender.
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Sadun AA, Carelli V, Salomao SR, Berezovsky A, Quiros PA, Sadun F, DeNegri AM, Andrade R, Moraes M, Passos A, Kjaer P, Pereira J, Valentino ML, Schein S, Belfort R. Extensive investigation of a large Brazilian pedigree of 11778/haplogroup J Leber hereditary optic neuropathy. Am J Ophthalmol 2003; 136:231-8. [PMID: 12888043 DOI: 10.1016/s0002-9394(03)00099-0] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To conduct systematic epidemiologic, neuro-ophthalmologic, psychophysical, and mitochondrial DNA (mtDNA) genetic examinations on a newly identified pedigree with Leber hereditary optic neuropathy (LHON). DESIGN Observational population cohort study. METHODS A prospective investigation of an entire Brazilian LHON family. SETTING A field investigation by an international team conducted in a remote part of Brazil. STUDY POPULATION We evaluated 265 (both eyes) of the 328 living family members of this LHON pedigree. Only members of this pedigree were studied. Those entering the pedigree as spouses were used as controls. OBSERVATION PROCEDURES We conducted epidemiologic interviews emphasizing possible environmental risk factors, comprehensive neuro-ophthalmologic examinations, psychophysical tests, Humphrey visual field studies, fundus photography, and blood testing for mitochondrial genetic analysis. RESULTS We reconstructed a seven-generation maternal lineage descended from a common ancestor dating to the 1870s. All maternally related family members were invariably homoplasmic 11778 with a haplogroup J mtDNA, 33 being affected, of which 22 are still living. With each subsequent generation, there was a progressive decrease of penetrance, and only males were affected in the last two generations. A significant exposure (greater than 95% confidence intervals) to a variety of environmental risk factors characterized the affected individuals, with smoking as the most common (P <.01). Both affected and carriers (95% confidence intervals) presented with a significantly lower incidence of hypertension and high cholesterol compared with the control group (P <.05). CONCLUSIONS Almost 95% of a 328-living-member pedigree with LHON 11778/J haplogroup was comprehensively studied. Our initial results indicate the strong influence of environmental risk factors. The remarkably reduced incidence of cardiovascular risk in the maternal lineage is discussed. Further genetic analysis may reveal a role for the nuclear genome.
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Affiliation(s)
- Alfredo A Sadun
- Keck-University of Southern California School of Medicine/Doheny Eye Institute, Los Angeles, CA 90033, USA.
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Sadun AA, Carelli V, Salomao SR, Berezovsky A, Quiros P, Sadun F, DeNegri AM, Andrade R, Schein S, Belfort R. A very large Brazilian pedigree with 11778 Leber's hereditary optic neuropathy. Trans Am Ophthalmol Soc 2002; 100:169-78; discussion 178-9. [PMID: 12545691 PMCID: PMC1358960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
PURPOSE We conducted extensive epidemiological, neuro-ophthalmological, psychophysical, and blood examinations on a newly discovered, very large pedigree with molecular analysis showing mtDNA mutation for Leber's hereditary optic neuropathy (LHON). METHODS Four patients representing four index cases from a remote area of Brazil were sent to Sao Paulo, where complete ophthalmological examinations strongly suggested LHON. Molecular analysis of their blood demonstrated that they were LHON, homoplasmic 11778, J-haplogroup. They had an extensive family that all lived in one rural area in Brazil. To investigate this family, we drew on a number of international experts to form a team that traveled to Brazil. This field team also included several members of the Federal University of Sao Paulo, and together we evaluated 273 of the 295 family members that were still alive. We conducted epidemiological interviews emphasizing possible environmental risk factors, comprehensive neuro-ophthalmological examinations, psychophysical tests, Humphrey visual field studies, fundus photography, and blood testing for both mitochondrial genetic analysis and nuclear gene linkage analysis. RESULTS The person representing the first-generation case immigrated from Verona, Italy, to Colatina. Subsequent generations demonstrated penetrance rates of 71%, 60%, 34%, 15%, and 9%. The percentages of males were 60%, 50%, 64%, 100%, and 100%. Age at onset varied from 10 to 64 years, and current visual acuities varied from LP to 20/400. CONCLUSIONS Almost 95% of a nearly 300-member pedigree with LHON 11778 were comprehensively studied. Analysis of environmental risk factors and a nuclear modifying factor from this group may help address the perplexing mystery of LHON: Why do only some of the genetically affected individuals manifest the disease? This fully described database may also provide an excellent opportunity for future clinical trials of any purported neuroprotective agent.
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Affiliation(s)
- Alfredo A Sadun
- University of Southern California-Keck School of Medicine/Doheny Eye Institute, Los Angeles, USA
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