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Werner S, Okenve-Ramos P, Hehlert P, Zitouni S, Priya P, Mendonça S, Sporbert A, Spalthoff C, Göpfert MC, Jana SC, Bettencourt-Dias M. IFT88 maintains sensory function by localising signalling proteins along Drosophila cilia. Life Sci Alliance 2024; 7:e202302289. [PMID: 38373798 PMCID: PMC10876440 DOI: 10.26508/lsa.202302289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/21/2024] Open
Abstract
Ciliary defects cause several ciliopathies, some of which have late onset, suggesting cilia are actively maintained. Still, we have a poor understanding of the mechanisms underlying their maintenance. Here, we show Drosophila melanogaster IFT88 (DmIFT88/nompB) continues to move along fully formed sensory cilia. We further identify Inactive, a TRPV channel subunit involved in Drosophila hearing and negative-gravitaxis behaviour, and a yet uncharacterised Drosophila Guanylyl Cyclase 2d (DmGucy2d/CG34357) as DmIFT88 cargoes. We also show DmIFT88 binding to the cyclase´s intracellular part, which is evolutionarily conserved and mutated in several degenerative retinal diseases, is important for the ciliary localisation of DmGucy2d. Finally, acute knockdown of both DmIFT88 and DmGucy2d in ciliated neurons of adult flies caused defects in the maintenance of cilium function, impairing hearing and negative-gravitaxis behaviour, but did not significantly affect ciliary ultrastructure. We conclude that the sensory ciliary function underlying hearing in the adult fly requires an active maintenance program which involves DmIFT88 and at least two of its signalling transmembrane cargoes, DmGucy2d and Inactive.
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Affiliation(s)
- Sascha Werner
- https://ror.org/04b08hq31 Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Pilar Okenve-Ramos
- https://ror.org/04b08hq31 Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Philip Hehlert
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Sihem Zitouni
- https://ror.org/04b08hq31 Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Institut de Génétique Humaine (IGH), UMR, 9002 CNRS, Montpellier, France
| | - Pranjali Priya
- National Centre for Biological Sciences- TIFR, Bangalore, India
| | - Susana Mendonça
- https://ror.org/04b08hq31 Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Anje Sporbert
- Advanced Light Microscopy, Max Delbrück Centrum for Molecular Medicine Berlin in the Helmholtz Association, Berlin, Germany
| | - Christian Spalthoff
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Martin C Göpfert
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Swadhin Chandra Jana
- https://ror.org/04b08hq31 Instituto Gulbenkian de Ciência, Oeiras, Portugal
- National Centre for Biological Sciences- TIFR, Bangalore, India
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2
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Jolly JK, Rodda BM, Edwards TL, Ayton LN, Ruddle JB. Optical coherence tomography in children with inherited retinal disease. Clin Exp Optom 2024; 107:255-266. [PMID: 38252959 DOI: 10.1080/08164622.2023.2294807] [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: 02/13/2023] [Accepted: 12/06/2023] [Indexed: 01/24/2024] Open
Abstract
Recent advances have led to therapeutic options becoming available for people with inherited retinal disease. In particular, gene therapy has been shown to hold great promise for slowing vision loss from inherited retinal disease. Recent studies suggest that gene therapy is likely to be most effective when implemented early in the disease process, making consideration of paediatric populations important. It is therefore necessary to have a comprehensive understanding of retinal imaging in children with inherited retinal diseases, in order to monitor disease progression and to determine which early retinal biomarkers may be used as outcome measures in future clinical trials. In addition, as many optometrists will review children with an inherited retinal disease, an understanding of the expected imaging outcomes can improve clinical care. This review focuses on the most common imaging modality used in research assessment of paediatric inherited retinal diseases: optical coherence tomography. Optical coherence tomography findings can be used in both the clinical and research setting. In particular, the review discusses current knowledge of optical coherence tomography findings in eight paediatric inherited retinal diseases - Stargardt disease, Bests disease, Leber's congenital amaurosis, choroideremia, RPGR related retinitis pigmentosa, Usher syndrome, X-linked retinoschisis and, Batten disease.
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Affiliation(s)
- Jasleen K Jolly
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Brent M Rodda
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia
| | - Thomas L Edwards
- Ophthalmology, Department of Surgery, The University of Melbourne, East Melbourne, Victoria, Australia
- Centre for Eye Research Australia, The Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Lauren N Ayton
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia
- Ophthalmology, Department of Surgery, The University of Melbourne, East Melbourne, Victoria, Australia
- Centre for Eye Research Australia, The Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Jonathan B Ruddle
- Centre for Eye Research Australia, The Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Department of Ophthalmology, Royal Children's Hospital, Parkville, Victoria, Australia
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3
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Sather R, Ihinger J, Simmons M, Lobo GP, Montezuma SR. The Clinical Findings, Pathogenic Variants, and Gene Therapy Qualifications Found in a Leber Congenital Amaurosis Phenotypic Spectrum Patient Cohort. Int J Mol Sci 2024; 25:1253. [PMID: 38279252 PMCID: PMC10816538 DOI: 10.3390/ijms25021253] [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: 12/15/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
This retrospective study examines the clinical characteristics and underlying genetic variants that exist in a Leber congenital amaurosis (LCA) patient cohort evaluated at the inherited retinal disease (IRD) clinic at the University of Minnesota (UMN)/M Health System. Our LCA cohort consisted of 33 non-syndromic patients and one patient with Joubert syndrome. We report their relevant history, clinical findings, and genetic testing results. We monitored disease presentation utilizing ocular coherence tomography (OCT) and fundus autofluorescence (FAF). Electroretinogram testing (ERG) was performed in patients when clinically indicated. Next-generation sequencing (NGS) and genetic counseling was offered to all evaluated patients. Advanced photoreceptor loss was noted in 85.7% of the subjects. All patients who underwent FAF had findings of either a ring of macular hypo/hyper AF or peripheral hypo-AF. All patients had abnormal ERG findings. A diagnostic genetic test result was identified in 74.2% of the patients via NGS single-gene testing or panel testing. Two patients in our cohort qualified for Luxturna® and both received treatment at the time of this study. These data will help IRD specialists to understand the genetic variants and clinical presentations that characterize our patient population in the Midwest region of the United States.
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Affiliation(s)
| | | | | | | | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, MN 55455, USA; (R.S.III); (J.I.); (G.P.L.)
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4
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Shi LF, Hall AJ, Thompson DA. Full-field stimulus threshold testing: a scoping review of current practice. Eye (Lond) 2024; 38:33-53. [PMID: 37443335 PMCID: PMC10764876 DOI: 10.1038/s41433-023-02636-3] [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: 01/07/2023] [Revised: 04/21/2023] [Accepted: 06/13/2023] [Indexed: 07/15/2023] Open
Abstract
The full-field stimulus threshold (FST) is a psychophysical measure of whole-field retinal light sensitivity. It can assess residual visual function in patients with severe retinal disease and is increasingly being adopted as an endpoint in clinical trials. FST applications in routine ophthalmology clinics are also growing, but as yet there is no formalised standard guidance for measuring FST. This scoping review explored current variability in FST conduct and reporting, with an aim to inform further evidence synthesis and consensus guidance. A comprehensive electronic search and review of the literature was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis Extension for Scoping Reviews (PRISMA-ScR) checklist. Key source, participant, methodology and outcomes data from 85 included sources were qualitatively and quantitatively compared and summarised. Data from 85 sources highlight how the variability and insufficient reporting of FST methodology, including parameters such as units of flash luminance, colour, duration, test strategy and dark adaptation, can hinder comparison and interpretation of clinical significance across centres. The review also highlights an unmet need for paediatric-specific considerations for test optimisation. Further evidence synthesis, empirical research or structured panel consultation may be required to establish coherent standardised guidance on FST methodology and context or condition dependent modifications. Consistent reporting of core elements, most crucially the flash luminance equivalence to 0 dB reference level is a first step. The development of criteria for quality assurance, calibration and age-appropriate reference data generation may further strengthen rigour of measurement.
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Affiliation(s)
- Linda F Shi
- Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- College of Health and Life Sciences, Aston University, Birmingham, UK
| | - Amanda J Hall
- College of Health and Life Sciences, Aston University, Birmingham, UK
| | - Dorothy A Thompson
- Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
- UCL Great Ormond Street Institute for Child Health, University College London, London, UK.
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5
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Li S, Ma H, Yang F, Ding X. cGMP Signaling in Photoreceptor Degeneration. Int J Mol Sci 2023; 24:11200. [PMID: 37446378 PMCID: PMC10342299 DOI: 10.3390/ijms241311200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Photoreceptors in the retina are highly specialized neurons with photosensitive molecules in the outer segment that transform light into chemical and electrical signals, and these signals are ultimately relayed to the visual cortex in the brain to form vision. Photoreceptors are composed of rods and cones. Rods are responsible for dim light vision, whereas cones are responsible for bright light, color vision, and visual acuity. Photoreceptors undergo progressive degeneration over time in many hereditary and age-related retinal diseases. Despite the remarkable heterogeneity of disease-causing genes, environmental factors, and pathogenesis, the progressive death of rod and cone photoreceptors ultimately leads to loss of vision/blindness. There are currently no treatments available for retinal degeneration. Cyclic guanosine 3', 5'-monophosphate (cGMP) plays a pivotal role in phototransduction. cGMP governs the cyclic nucleotide-gated (CNG) channels on the plasma membrane of the photoreceptor outer segments, thereby regulating membrane potential and signal transmission. By gating the CNG channels, cGMP regulates cellular Ca2+ homeostasis and signal transduction. As a second messenger, cGMP activates the cGMP-dependent protein kinase G (PKG), which regulates numerous targets/cellular events. The dysregulation of cGMP signaling is observed in varieties of photoreceptor/retinal degenerative diseases. Abnormally elevated cGMP signaling interferes with various cellular events, which ultimately leads to photoreceptor degeneration. In line with this, strategies to reduce cellular cGMP signaling result in photoreceptor protection in mouse models of retinal degeneration. The potential mechanisms underlying cGMP signaling-induced photoreceptor degeneration involve the activation of PKG and impaired Ca2+ homeostasis/Ca2+ overload, resulting from overactivation of the CNG channels, as well as the subsequent activation of the downstream cellular stress/death pathways. Thus, targeting the cellular cGMP/PKG signaling and the Ca2+-regulating pathways represents a significant strategy for photoreceptor protection in retinal degenerative diseases.
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Affiliation(s)
| | | | | | - Xiqin Ding
- Department of Cell Biology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.L.); (H.M.); (F.Y.)
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6
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Boye SL, O’Riordan C, Morris J, Lukason M, Compton D, Baek R, Elmore DM, Peterson J, Fajardo D, McCullough KT, Scaria A, McVie-Wylie A, Boye SE. Preclinical studies in support of phase I/II clinical trials to treat GUCY2D-associated Leber congenital amaurosis. Mol Ther Methods Clin Dev 2023; 28:129-145. [PMID: 36654798 PMCID: PMC9830033 DOI: 10.1016/j.omtm.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Mutations in GUCY2D are associated with severe early-onset retinal dystrophy, Leber congenital amaurosis type 1 (LCA1), a leading cause of blindness in children. Despite a high degree of visual disturbance stemming from photoreceptor dysfunction, patients with LCA1 largely retain normal photoreceptor structure, suggesting that they are good candidates for gene replacement therapy. The purpose of this study was to conduct the preclinical and IND-enabling experiments required to support clinical application of AAV5-hGRK1-GUCY2D in patients harboring biallelic recessive mutations in GUCY2D. Preclinical studies were conducted in mice to evaluate the effect of vector manufacturing platforms and transgene species on the therapeutic response. Dose-ranging studies were conducted in cynomolgus monkeys to establish the minimum dose required for efficient photoreceptor transduction. Good laboratory practice (GLP) studies evaluated systemic biodistribution in rats and toxicology in non-human primates (NHPs). These results expanded our knowledge of dose response for an AAV5-vectored transgene under control of the human rhodopsin kinase (hGRK1) promoter in NHPs with respect to photoreceptor transduction and safety and, in combination with the rat biodistribution and mouse efficacy studies, informed the design of a first-in-human clinical study in patients with LCA1.
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Affiliation(s)
- Sanford L. Boye
- Powell Gene Therapy Center, Department of Pediatrics, University of Florida, Gainesville, FL 32610, USA
| | | | | | | | | | | | | | | | | | | | | | | | - Shannon E. Boye
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida, PO Box 100296, Gainesville, FL 32610, USA
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7
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Aleman TS, O'Neil EC, Uyhazi KE, Parchinski KM, Santos AJ, Weber ML, Colclough SP, Billek AS, Zhu X, Leroy BP, Bedoukian EC. Fleck-like lesions in CEP290-associated leber congenital amaurosis: a case series. Ophthalmic Genet 2022; 43:824-833. [PMID: 36469661 DOI: 10.1080/13816810.2022.2147960] [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: 12/12/2022]
Abstract
PURPOSE To provide a detailed ophthalmic phenotype of a small cohort of patients with Leber Congenital Amaurosis (LCA) caused by mutations in CEP290 (CEP290-LCA) with a focus on elucidating the origin of yellow-white lesions observed in 30% of patients with this condition. METHODS This is a retrospective review of records of five patients with CEP290-LCA. Patients had comprehensive ophthalmic evaluations. Visual function was assessed with full-field electroretinograms (ffERGs) and full-field sensitivity testing (FST). Multimodal imaging was performed with spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) with short- (SW) and near-infrared (NIR) excitation wavelengths. RESULTS All patients showed relative structural preservation of the foveal and near midperipheral retina separated by a pericentral area of photoreceptor loss. Yellow-white, fleck-like lesions in an annular distribution around the near midperiphery co-localized with hyperreflective lesions on SD-OCT. The lesions located between the inner segment ellipsoid signal and the apical retinal pigment epithelium (RPE). The inner retina was normal. Longitudinal observations in one of the patients indicates the abnormalities may represent an intermediate stage in the degenerative process between the near normal appearing retina previously documented in young CEP290-LCA patients and the pigmentary retinopathy observed along the same region in older individuals. CONCLUSIONS We speculate that fleck-like lesions in CEP290-LCA correspond to malformed, rudimentary or degenerated, including shed, photoreceptor outer segments. The topography and possible origin of the abnormalities may inform the planning of evolving genetic therapies for this disease.
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Affiliation(s)
- Tomas S Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Erin C O'Neil
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katherine E Uyhazi
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kelsey M Parchinski
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Arlene J Santos
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mariejel L Weber
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sherice P Colclough
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrew S Billek
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xiaosong Zhu
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bart P Leroy
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Head & Skin, Ghent University, Ghent, Belgium.,Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Emma C Bedoukian
- The Division of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Individualized Medical Genetics Center of the Children's Hospital of Philadelphia, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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8
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Jacobson SG, Cideciyan AV, Ho AC, Roman AJ, Wu V, Garafalo AV, Sumaroka A, Krishnan AK, Swider M, Mascio AA, Kay CN, Yoon D, Fujita KP, Boye SL, Peshenko IV, Dizhoor AM, Boye SE. Night vision restored in days after decades of congenital blindness. iScience 2022; 25:105274. [PMID: 36274938 PMCID: PMC9579015 DOI: 10.1016/j.isci.2022.105274] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/29/2022] [Accepted: 09/30/2022] [Indexed: 11/29/2022] Open
Abstract
Signaling of vision to the brain starts with the retinal phototransduction cascade which converts visible light from the environment into chemical changes. Vision impairment results when mutations inactivate proteins of the phototransduction cascade. A severe monogenically inherited blindness, Leber congenital amaurosis (LCA), is caused by mutations in the GUCY2D gene, leading to a molecular defect in the production of cyclic GMP, the second messenger of phototransduction. We studied two patients with GUCY2D-LCA who were undergoing gene augmentation therapy. Both patients had large deficits in rod photoreceptor-based night vision before intervention. Within days of therapy, rod vision in both patients changed dramatically; improvements in visual function and functional vision in these hyper-responding patients reached more than 3 log10 units (1000-fold), nearing healthy rod vision. Quick activation of the complex molecular pathways from retinal photoreceptor to visual cortex and behavior is thus possible in patients even after being disabled and dormant for decades.
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Affiliation(s)
- Samuel G. Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Artur V. Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Allen C. Ho
- Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Alejandro J. Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vivian Wu
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexandra V. Garafalo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Arun K. Krishnan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Malgorzata Swider
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Abraham A. Mascio
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Dan Yoon
- Atsena Therapeutics, Inc., Durham, NC 27709, USA
| | | | - Sanford L. Boye
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL 32601, USA
| | - Igor V. Peshenko
- Pennsylvania College of Optometry, Salus University, Elkins Park, PA 19027, USA
| | | | - Shannon E. Boye
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL 32611, USA
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9
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Mobility test to assess functional vision in dark-adapted patients with Leber congenital amaurosis. BMC Ophthalmol 2022; 22:266. [PMID: 35701753 PMCID: PMC9195222 DOI: 10.1186/s12886-022-02475-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 06/01/2022] [Indexed: 11/30/2022] Open
Abstract
Background Inherited retinal degenerations (IRDs) affect daylight and night vision to different degrees. In the current work, we devise a method to quantify mobility under dark-adapted conditions in patients with severe childhood blindness due to Leber congenital amaurosis (LCA). Mobility thresholds from two different LCA genotypes are compared to dark-adapted vision measurements using the full-field stimulus test (FST), a conventional desktop outcome measure of rod vision. Methods A device consisting of vertical LED strips on a plane resembling a beaded curtain was programmed to produce a rectangular pattern target defining a ‘door’ of varying luminance that could appear at one of three positions. Mobility performance was evaluated by letting the subject walk from a fixed starting position ~ 4 m away from the device with instructions to touch the door. Success was defined as the subject touching within the ‘door’ area. Ten runs were performed and the process was repeated for different levels of luminance. Tests were performed monocularly in dark-adapted and dilated eyes. Results from LCA patients with the GUCY2D and CEP290 genotypes and normal subjects were analyzed using logistic regression to estimate the mobility threshold for successful navigation. The relation of thresholds for mobility, FST and visual acuity were quantified using linear regression. Results Normal subjects had mobility thresholds near limits of dark-adapted rod vision. GUCY2D-LCA patients had a wide range of mobility thresholds from within 1 log of normal to greater than 8 log abnormal. CEP290-LCA patients had abnormal mobility thresholds that were between 5 and 6 log from normal. Sensitivity loss estimates using FST related linearly to the mobility thresholds which were not correlated with visual acuity. Conclusions The mobility task we developed can quantify functional vision in severely disabled patients with LCA. Taken together with other outcome measures of rod and cone photoreceptor-mediated vision, dark-adapted functional vision should provide a more complete understanding of the natural history and effects of treatment in patients with LCA. Supplementary Information The online version contains supplementary material available at 10.1186/s12886-022-02475-y.
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10
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Gesemann M, Neuhauss SCF. Selective Gene Loss of Visual and Olfactory Guanylyl Cyclase Genes Following the Two Rounds of Vertebrate-Specific Whole-Genome Duplications. Genome Biol Evol 2021; 12:2153-2167. [PMID: 32915957 PMCID: PMC7674705 DOI: 10.1093/gbe/evaa192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2020] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors convey visual information and come in two flavors; dim-light and bright-light dedicated rod and cones. Both cell types feature highly specialized phototransduction cascades that convert photonic energy into intracellular signals. Although a substantial amount of phototransduction gene ohnologs are expressed either in rods or cones, visual guanylyl cyclases (GCs) involved in the calcium (Ca2+) dependent feedback regulation of phototransduction are neither rod nor cone specific. The co-existence of visual GCs in both photoreceptor types suggests that specialization of these ohnologs occurred despite their overlapping expression. Here, we analyze gene retention and inactivation patterns of vertebrate visual and closely related olfactory GCs following two rounds (2R) of vertebrate-specific whole-genome duplication events (2R WGD). Although eutherians generally use two visual and one olfactory GC, independent inactivation occurred in some lineages. Sauropsids (birds, lizards, snakes, turtles, and crocodiles) generally have only one visual GC (GC-E). Additionally, turtles (testodes) also lost the olfactory GC (GC-D). Pseudogenization in mammals occurred in specific species/families likely according to functional needs (i.e., many species with reduced vision only have GC-E). Likewise, some species not relying on scent marks lack GC-D, the olfactory GC enzyme. Interestingly, in the case of fish, no species can be found with fewer than three (two visual and one olfactory) genes and the teleost-specific 3R WGD can increase this number to up to five. This suggests that vision in fish now requires at least two visual GCs.
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Affiliation(s)
- Matthias Gesemann
- Institute of Molecular Life Sciences, University of Zurich, Switzerland
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11
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Krishnan AK, Roman AJ, Swider M, Jacobson SG, Cideciyan AV. Macular Rod Function in Retinitis Pigmentosa Measured With Scotopic Microperimetry. Transl Vis Sci Technol 2021; 10:3. [PMID: 34473224 PMCID: PMC8419874 DOI: 10.1167/tvst.10.11.3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Purpose To investigate the validity and reliability of macular rod photoreceptor function measurement with a microperimeter. Methods Macular sensitivity in dark-adapted retinitis pigmentosa (RP) patients (22 eyes; 9–67 years of age) and controls (five eyes; 22–55 years of age) was assessed with a modified Humphrey field analyzer (mHFA), as well as a scotopic microperimeter (Nidek MP-1S). Sensitivity loss (SL) was estimated at rod-mediated locations. All RP eyes were re-evaluated at a second visit 6 months later. The dynamic range of the MP-1S was expanded with a range of neutral-density filters (NDFs). Results In controls, a 4 NDF was used at all macular locations tested. In patients with RP, 0 to 3 NDFs were used, depending on the local disease severity. At rod-mediated locations (n = 281), SL estimates obtained with the MP-1S were highly correlated (r = 0.80) with those of the mHFA. The inter-perimeter difference of SL averaged less than 3 decibels (dB) with all NDFs, except those with most severe locations evaluated with a 0 NDF, where the difference averaged more than 6 dB. The results were similar on the second visit. Conclusions The MP-1S estimates of SL are highly correlated with those of the mHFA over a wide range of disease severity replicated at two visits; however, there was an unexplained bias in the magnitude of SL estimated by the MP-1S especially at loci with severe disease. Translational Relevance MP-1S scotopic microperimetry can be used to evaluate changes to macular rod function, but evaluation of treatment potential by quantitative comparison of SL to retinal structure will be more challenging.
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Affiliation(s)
- Arun K Krishnan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alejandro J Roman
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Malgorzata Swider
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Roman AJ, Cideciyan AV, Wu V, Garafalo AV, Jacobson SG. Full-field stimulus testing: Role in the clinic and as an outcome measure in clinical trials of severe childhood retinal disease. Prog Retin Eye Res 2021; 87:101000. [PMID: 34464742 DOI: 10.1016/j.preteyeres.2021.101000] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 12/27/2022]
Abstract
Disease mechanisms have become better understood in previously incurable forms of early-onset severe retinal dystrophy, such as Leber congenital amaurosis (LCA). This has led to novel treatments and clinical trials that have shown some success. Standard methods to measure vision were difficult if not impossible to perform in severely affected patients with low vision and nystagmus. To meet the need for visual assays, we devised a psychophysical method, which we named full-field stimulus testing (FST). From early versions based on an automated perimeter, we advanced FST to a more available light-emitting diode platform. The journey from invention to use of such a technique in our inherited retinal degeneration clinic is reviewed and many of the lessons learned over the 15 years of application of FST are explained. Although the original purpose and application of FST was to quantify visual thresholds in LCA, there are rare opportunities for FST also to be used beyond LCA to measure aspects of vision in other inherited retinal degenerations; examples are given. The main goal of the current review, however, remains to enable investigators studying and treating LCA to understand how to best use FST and how to reduce artefact and confounding complexities so the test results become more valuable to the understanding of LCA diseases and results of novel interventions.
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Affiliation(s)
- Alejandro J Roman
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Vivian Wu
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alexandra V Garafalo
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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13
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Huang CH, Yang CM, Yang CH, Hou YC, Chen TC. Leber's Congenital Amaurosis: Current Concepts of Genotype-Phenotype Correlations. Genes (Basel) 2021; 12:genes12081261. [PMID: 34440435 PMCID: PMC8392113 DOI: 10.3390/genes12081261] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Leber’s congenital amaurosis (LCA), one of the most severe inherited retinal dystrophies, is typically associated with extremely early onset of visual loss, nystagmus, and amaurotic pupils, and is responsible for 20% of childhood blindness. With advances in molecular diagnostic technology, the knowledge about the genetic background of LCA has expanded widely, while disease-causing variants have been identified in 38 genes. Different pathogenetic mechanisms have been found among these varieties of genetic mutations, all of which result in the dysfunction or absence of their encoded proteins participating in the visual cycle. Hence, the clinical phenotypes also exhibit extensive heterogenicity, including the course of visual impairment, involvement of the macular area, alteration in retinal structure, and residual function of the diseased photoreceptor. By reviewing the clinical course, fundoscopic images, optical coherent tomography examination, and electroretinogram, genotype-phenotype correlations could be established for common genetic mutations in LCA, which would benefit the timing of the diagnosis and thus promote early intervention. Gene therapy is promising in the management of LCA, while several clinical trials are ongoing and preliminary success has been announced, focusing on RPE65 and other common disease-causing genes. This review provides an update on the genetics, clinical examination findings, and genotype-phenotype correlations in the most well-established causative genetic mutations of LCA.
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Affiliation(s)
- Chu-Hsuan Huang
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Yu-Chih Hou
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Correspondence: ; Tel.: +886-2-23123456
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14
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Cideciyan AV, Krishnan AK, Roman AJ, Sumaroka A, Swider M, Jacobson SG. Measures of Function and Structure to Determine Phenotypic Features, Natural History, and Treatment Outcomes in Inherited Retinal Diseases. Annu Rev Vis Sci 2021; 7:747-772. [PMID: 34255540 DOI: 10.1146/annurev-vision-032321-091738] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Inherited retinal diseases (IRDs) are at the forefront of innovative gene-specific treatments because of the causation by single genes, the availability of microsurgical access for treatment delivery, and the relative ease of quantitative imaging and vision measurement. However, it is not always easy to choose a priori, from scores of potential measures, an appropriate subset to evaluate efficacy outcomes considering the wide range of disease stages with different phenotypic features. This article reviews measurements of visual function and retinal structure that our group has used over the past three decades to understand the natural history of IRDs. We include measures of light sensitivity, retinal structure, mapping of natural fluorophores, evaluation of pupillary light reflex, and oculomotor control. We provide historical context and examples of applicability. We also review treatment trial outcomes using these measures of function and structure. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Artur V Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Arun K Krishnan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Alejandro J Roman
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Alexander Sumaroka
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Malgorzata Swider
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
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15
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Jacobson SG, Cideciyan AV, Ho AC, Peshenko IV, Garafalo AV, Roman AJ, Sumaroka A, Wu V, Krishnan AK, Sheplock R, Boye SL, Dizhoor AM, Boye SE. Safety and improved efficacy signals following gene therapy in childhood blindness caused by GUCY2D mutations. iScience 2021; 24:102409. [PMID: 33997691 PMCID: PMC8099775 DOI: 10.1016/j.isci.2021.102409] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/04/2021] [Accepted: 04/06/2021] [Indexed: 12/11/2022] Open
Abstract
A first-in-human clinical trial of gene therapy in Leber congenital amaurosis due to mutations in the GUCY2D gene is underway, and early results are summarized. A recombinant adeno-associated virus serotype 5 (rAAV5) vector carrying the human GUCY2D gene was delivered by subretinal injection to one eye in three adult patients with severe visual loss, nystagmus, but preserved retinal structure. Safety and efficacy parameters were monitored for 9 months post-operatively. No systemic toxicity was detected; there were no serious adverse events, and ocular adverse events resolved. P1 and P2 showed statistically significant rod photoreceptor vision improvement by full-field stimulus testing in the treated eye. P1 also showed improvement in pupillary responses. Visual acuity remained stable from baseline in P1 and P2. P3, however, showed a gain of 0.3 logMAR in the treated eye, indicating greater cone-photoreceptor function. The results show safety and both rod- and cone-mediated efficacy of this therapy.
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Affiliation(s)
- Samuel G. Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Artur V. Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Allen C. Ho
- Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA, USA
| | - Igor V. Peshenko
- Pennsylvania College of Optometry, Salus University, Elkins Park, PA, USA
| | - Alexandra V. Garafalo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alejandro J. Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Vivian Wu
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Arun K. Krishnan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Rebecca Sheplock
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sanford L. Boye
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | | | - Shannon E. Boye
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
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16
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Cideciyan AV, Jacobson SG, Ho AC, Garafalo AV, Roman AJ, Sumaroka A, Krishnan AK, Swider M, Schwartz MR, Girach A. Durable vision improvement after a single treatment with antisense oligonucleotide sepofarsen: a case report. Nat Med 2021; 27:785-789. [PMID: 33795869 PMCID: PMC8127404 DOI: 10.1038/s41591-021-01297-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/01/2021] [Indexed: 12/21/2022]
Abstract
Leber congenital amaurosis due to CEP290 ciliopathy is being explored by treatment with the antisense oligonucleotide (AON) sepofarsen. One patient who was part of a larger cohort (ClinicalTrials.gov NCT03140969 ) was studied for 15 months after a single intravitreal sepofarsen injection. Concordant measures of visual function and retinal structure reached a substantial efficacy peak near 3 months after injection. At 15 months, there was sustained efficacy, even though there was evidence of reduction from peak response. Efficacy kinetics can be explained by the balance of AON-driven new CEP290 protein synthesis and a slow natural rate of CEP290 protein degradation in human foveal cone photoreceptors.
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Affiliation(s)
- Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Allen C Ho
- Wills Eye Hospital, Thomas Jefferson University, Philadelphia PA, USA
| | - Alexandra V Garafalo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alejandro J Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Arun K Krishnan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Malgorzata Swider
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Aleman TS, Miller AJ, Maguire KH, Aleman EM, Serrano LW, O'Connor KB, Bedoukian EC, Leroy BP, Maguire AM, Bennett J. A Virtual Reality Orientation and Mobility Test for Inherited Retinal Degenerations: Testing a Proof-of-Concept After Gene Therapy. Clin Ophthalmol 2021; 15:939-952. [PMID: 33688162 PMCID: PMC7936670 DOI: 10.2147/opth.s292527] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/22/2021] [Indexed: 12/19/2022] Open
Abstract
Purpose To test the ability of a virtual reality (VR) orientation and mobility (O&M) protocol to serve a measure of functional vision for patients with inherited retinal degenerations (IRDs). Methods A VR-O&M protocol designed using a commercially available VR hardware was tested in normally sighted control subjects (n=7; ages 10–35yo; Average 22.5yo) and patients with RPE65-associated Leber Congenital Amaurosis (n=3; ages 7–18yo; Average 12.7yo), in two of them before and after gene therapy. Patients underwent perimetry and full-field sensitivity testing. VR-O&M parameters correlated with the visual dysfunction. Results Visual acuities in RPE65 patients were on average worse than 20/200, dark-adapted sensitivity losses >5 log units, and fields constricted between 20° and 40°. Before treatment, patients required ~1000-fold brighter environment to navigate, had at least x4 more collisions, and were slower both to orient and navigate compared to control subjects. Improvements in cone- (by 1–2 L.u.) and rod-mediated (by >4 L.u.) sensitivities post-treatment led to fewer collisions (at least by half) at ~100-fold dimmer luminances, and to x4 times faster navigation times. Conclusion This study provides proof-of-concept data in support for the use of VR-O&M systems to quantify the impact that the visual dysfunction and improvement of vision following treatments has on functional vision in IRDs. The VR-O&M was useful in potentially challenging scenarios such as in pediatric patients with severe IRDs. Translational Relevance A VR-O&M test will provide much needed flexibility, both in its deployment as well as in the possibility to test various attributes of vision that may be impacted by gene therapy in the setting of translational studies. Precis This study provides proof-of-concept data in support for the use of a virtual reality orientation and mobility test to quantify the impact of the disease and of treatments thereof on functional vision in inherited retinal degenerations.
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Affiliation(s)
- Tomas S Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA.,Division of Ophthalmology at the Children's Hospital of Philadelphia of the Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander J Miller
- Neurology Virtual Reality Laboratory of the Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Katherine H Maguire
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Elena M Aleman
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Leona W Serrano
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Keli B O'Connor
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Emma C Bedoukian
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Bart P Leroy
- Division of Ophthalmology at the Children's Hospital of Philadelphia of the Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA.,Department of Pediatrics, Ghent University, Ghent, Belgium.,Department of Ophthalmology, Ghent University, Ghent, Belgium.,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Albert M Maguire
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA.,Division of Ophthalmology at the Children's Hospital of Philadelphia of the Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jean Bennett
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
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18
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Leber Congenital Amaurosis Due to GUCY2D Mutations: Longitudinal Analysis of Retinal Structure and Visual Function. Int J Mol Sci 2021; 22:ijms22042031. [PMID: 33670772 PMCID: PMC7922686 DOI: 10.3390/ijms22042031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 12/22/2022] Open
Abstract
Gene augmentation therapy is being planned for GUCY2D-associated Leber congenital amaurosis (LCA). To increase our understanding of the natural history of GUCY2D-LCA, patients were evaluated twice with an interval of 4 to 7 years between visits using safety and efficacy outcome measures previously determined to be useful for monitoring this disorder. In this group of molecularly-identified LCA patients (n = 10; ages 7–37 years at first visit), optical coherence tomography (OCT) was used to measure foveal cone outer nuclear layer (ONL) thickness and rod ONL at a superior retinal locus. Full-field stimulus testing (FST) with chromatic stimuli in dark- and light-adapted states was used to assay rod and cone vision. Changes in OCT and FST over the interval were mostly attributable to inter-visit variability. There were no major negative changes in structure or function across the cohort and over the intervals studied. Variation in severity of disease expression between patients occurs; however, despite difficulties in quantifying structure and function in such seriously visually impaired individuals with nystagmus, the present work supports the use of OCT as a safety outcome and FST as an efficacy outcome in a clinical trial of GUCY2D-LCA. A wide age spectrum for therapy was confirmed, and there was relative stability of structure and function during a typical time interval for clinical trials.
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19
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Regulation of retinal membrane guanylyl cyclase (RetGC) by negative calcium feedback and RD3 protein. Pflugers Arch 2021; 473:1393-1410. [PMID: 33537894 PMCID: PMC8329130 DOI: 10.1007/s00424-021-02523-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 11/07/2022]
Abstract
This article presents a brief overview of the main biochemical and cellular processes involved in regulation of cyclic GMP production in photoreceptors. The main focus is on how the fluctuations of free calcium concentrations in photoreceptors between light and dark regulate the activity of retinal membrane guanylyl cyclase (RetGC) via calcium sensor proteins. The emphasis of the review is on the structure of RetGC and guanylyl cyclase activating proteins (GCAPs) in relation to their functional role in photoreceptors and congenital diseases of photoreceptors. In addition to that, the structure and function of retinal degeneration-3 protein (RD3), which regulates RetGC in a calcium-independent manner, is discussed in detail in connections with its role in photoreceptor biology and inherited retinal blindness.
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20
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Peshenko IV, Olshevskaya EV, Dizhoor AM. GUCY2D mutations in retinal guanylyl cyclase 1 provide biochemical reasons for dominant cone-rod dystrophy but not for stationary night blindness. J Biol Chem 2020; 295:18301-18315. [PMID: 33109612 PMCID: PMC7939455 DOI: 10.1074/jbc.ra120.015553] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/23/2020] [Indexed: 11/07/2022] Open
Abstract
Mutations in the GUCY2D gene coding for the dimeric human retinal membrane guanylyl cyclase (RetGC) isozyme RetGC1 cause various forms of blindness, ranging from rod dysfunction to rod and cone degeneration. We tested how the mutations causing recessive congenital stationary night blindness (CSNB), recessive Leber's congenital amaurosis (LCA1), and dominant cone-rod dystrophy-6 (CORD6) affected RetGC1 activity and regulation by RetGC-activating proteins (GCAPs) and retinal degeneration-3 protein (RD3). CSNB mutations R666W, R761W, and L911F, as well as LCA1 mutations R768W and G982VfsX39, disabled RetGC1 activation by human GCAP1, -2, and -3. The R666W and R761W substitutions compromised binding of GCAP1 with RetGC1 in HEK293 cells. In contrast, G982VfsX39 and L911F RetGC1 retained the ability to bind GCAP1 in cyto but failed to effectively bind RD3. R768W RetGC1 did not bind either GCAP1 or RD3. The co-expression of GUCY2D allelic combinations linked to CSNB did not restore RetGC1 activity in vitro The CORD6 mutation R838S in the RetGC1 dimerization domain strongly dominated the Ca2+ sensitivity of cyclase regulation by GCAP1 in RetGC1 heterodimer produced by co-expression of WT and the R838S subunits. It required higher Ca2+ concentrations to decelerate GCAP-activated RetGC1 heterodimer-6-fold higher than WT and 2-fold higher than the Ser838-harboring homodimer. The heterodimer was also more resistant than homodimers to inhibition by RD3. The observed biochemical changes can explain the dominant CORD6 blindness and recessive LCA1 blindness, both of which affect rods and cones, but they cannot explain the selective loss of rod function in recessive CSNB.
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Affiliation(s)
- Igor V Peshenko
- Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania, USA
| | - Elena V Olshevskaya
- Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania, USA
| | - Alexander M Dizhoor
- Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania, USA.
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21
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Mendell JR, Al-Zaidy SA, Rodino-Klapac LR, Goodspeed K, Gray SJ, Kay CN, Boye SL, Boye SE, George LA, Salabarria S, Corti M, Byrne BJ, Tremblay JP. Current Clinical Applications of In Vivo Gene Therapy with AAVs. Mol Ther 2020; 29:464-488. [PMID: 33309881 PMCID: PMC7854298 DOI: 10.1016/j.ymthe.2020.12.007] [Citation(s) in RCA: 339] [Impact Index Per Article: 84.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/16/2020] [Accepted: 12/05/2020] [Indexed: 02/07/2023] Open
Abstract
Hereditary diseases are caused by mutations in genes, and more than 7,000 rare diseases affect over 30 million Americans. For more than 30 years, hundreds of researchers have maintained that genetic modifications would provide effective treatments for many inherited human diseases, offering durable and possibly curative clinical benefit with a single treatment. This review is limited to gene therapy using adeno-associated virus (AAV) because the gene delivered by this vector does not integrate into the patient genome and has a low immunogenicity. There are now five treatments approved for commercialization and currently available, i.e., Luxturna, Zolgensma, the two chimeric antigen receptor T cell (CAR-T) therapies (Yescarta and Kymriah), and Strimvelis (the gammaretrovirus approved for adenosine deaminase-severe combined immunodeficiency [ADA-SCID] in Europe). Dozens of other treatments are under clinical trials. The review article presents a broad overview of the field of therapy by in vivo gene transfer. We review gene therapy for neuromuscular disorders (spinal muscular atrophy [SMA]; Duchenne muscular dystrophy [DMD]; X-linked myotubular myopathy [XLMTM]; and diseases of the central nervous system, including Alzheimer’s disease, Parkinson’s disease, Canavan disease, aromatic l-amino acid decarboxylase [AADC] deficiency, and giant axonal neuropathy), ocular disorders (Leber congenital amaurosis, age-related macular degeneration [AMD], choroideremia, achromatopsia, retinitis pigmentosa, and X-linked retinoschisis), the bleeding disorder hemophilia, and lysosomal storage disorders.
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Affiliation(s)
- Jerry R Mendell
- Center of Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics and Neurology, The Ohio State University, Columbus, OH, USA
| | | | | | - Kimberly Goodspeed
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Sanford L Boye
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
| | - Shannon E Boye
- Division of Cellular and Molecular Therapeutics, University of Florida, Gainesville, FL, USA
| | - Lindsey A George
- Division of Hematology and the Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA, USA; Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Stephanie Salabarria
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Manuela Corti
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
| | - Barry J Byrne
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
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22
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Padhy SK, Takkar B, Narayanan R, Venkatesh P, Jalali S. Voretigene Neparvovec and Gene Therapy for Leber's Congenital Amaurosis: Review of Evidence to Date. APPLICATION OF CLINICAL GENETICS 2020; 13:179-208. [PMID: 33268999 PMCID: PMC7701157 DOI: 10.2147/tacg.s230720] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/06/2020] [Indexed: 12/13/2022]
Abstract
Gene therapy has now evolved as the upcoming modality for management of many disorders, both inheritable and non-inheritable. Knowledge of genetics pertaining to a disease has therefore become paramount for physicians across most specialities. Inheritable retinal dystrophies (IRDs) are notorious for progressive and relentless vision loss, frequently culminating in complete blindness in both eyes. Leber’s congenital amaurosis (LCA) is a typical example of an IRD that manifests very early in childhood. Research in gene therapy has led to the development and approval of voretigene neparvovec (VN) for use in patients of LCA with a deficient biallelic RPE65 gene. The procedure involves delivery of a recombinant virus vector that carries the RPE65 gene in the subretinal space. This comprehensive review reports the evidence thus far in support of gene therapy for LCA. We explore and compare the various gene targets including but not limited to RPE65, and discuss the choice of vector and method for ocular delivery. The review details the evolution of gene therapy with VN in a phased manner, concluding with the challenges that lie ahead for its translation for use in communities that differ much both genetically and economically.
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Affiliation(s)
- Srikanta Kumar Padhy
- Vitreoretina and Uveitis Services, L V Prasad Eye Institute, Mithu Tulsi Chanrai Campus, Bhubaneswar, India
| | - Brijesh Takkar
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, India.,Center of Excellence for Rare Eye Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India
| | - Raja Narayanan
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, India
| | - Pradeep Venkatesh
- Dr RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Subhadra Jalali
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, India.,Jasti V. Ramanamma Childrens' Eye Care Centre, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India
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Cameron MA, Morley JW, Pérez-Fernández V. Seeing the light: different photoreceptor classes work together to drive adaptation in the mammalian retina. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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24
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Krishnan AK, Jacobson SG, Roman AJ, Iyer BS, Garafalo AV, Héon E, Cideciyan AV. Transient pupillary light reflex in CEP290- or NPHP5-associated Leber congenital amaurosis: Latency as a potential outcome measure of cone function. Vision Res 2020; 168:53-63. [PMID: 32088401 PMCID: PMC7068155 DOI: 10.1016/j.visres.2020.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/08/2020] [Accepted: 01/13/2020] [Indexed: 12/16/2022]
Abstract
Mutations in photoreceptor cilium genes CEP290 and NPHP5 cause a form of Leber congenital amaurosis (LCA) which typically lacks rods but retains central cones. The current study evaluated the transient pupillary light reflex (TPLR) as an objective outcome measure to assess efficacy of ongoing and future therapies. Eleven eyes of six patients selected for retained cone function were tested with TPLR using full-field stimuli in the dark-adapted state. Stimuli were red or blue with 1 s duration and spanned a 6-log unit dynamic range. TPLR response amplitude was quantified at fixed times of 0.9 and 2 s after stimulus onset and TPLR latency was defined as the time to reach 0.3 mm constriction. Full-field stimulus testing (FST) and static perimetry were used to correlate subjective perception with objective TPLR parameters. TPLR and FST thresholds with both red and blue stimuli were abnormally elevated in patients to near -1.25 log phot-cd·m-2 consistent with the lack of rods. TPLR latencies were delayed on average but showed some differences among patients. Remnant extrafoveal vision was correlated with faster TPLR latencies. Our results support the use of a short TPLR protocol with full-field red stimuli of 0.7 log phot-cd·m-2 or brighter as an objective and convenient outcome measure of cone function in CEP290- and NPHP5-LCA. The latency parameter of the TPLR would be expected to show a detectable change when an intervention modifies cone sensitivity in the extrafoveal region.
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Affiliation(s)
- Arun K Krishnan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Alejandro J Roman
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Bhavya S Iyer
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Alexandra V Garafalo
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
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Bouzia Z, Georgiou M, Hull S, Robson AG, Fujinami K, Rotsos T, Pontikos N, Arno G, Webster AR, Hardcastle AJ, Fiorentino A, Michaelides M. GUCY2D-Associated Leber Congenital Amaurosis: A Retrospective Natural History Study in Preparation for Trials of Novel Therapies. Am J Ophthalmol 2020; 210:59-70. [PMID: 31704230 PMCID: PMC7013380 DOI: 10.1016/j.ajo.2019.10.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/21/2019] [Accepted: 10/23/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE To describe the natural history of Leber congenital amaurosis (LCA) associated with GUCY2D variants (GUCY2D-LCA) in a cohort of children and adults, in preparation for trials of novel therapies. DESIGN Retrospective case series. METHODS Participants: Patients with GUCY2D-LCA at a single referral center. PROCEDURES Review of clinical notes, retinal imaging including fundus autofluorescence (FAF) and optical coherence tomography (OCT), electroretinography (ERG), and molecular genetic testing. MAIN OUTCOME MEASURES Demographic data, symptoms at presentation, visual acuity, evidence of progression, OCT and FAF findings, ERG assessment, and molecular genetics. RESULTS Twenty-one subjects with GUCY2D-LCA were included, with a mean follow-up ± standard deviation (SD) of 10 ± 11.85 years. Marked reduction in visual acuity (VA) and nystagmus was documented in all patients within the first 3 years of life. Fifty-seven percent (n = 12) exhibited photophobia and 38% (n = 8) had nyctalopia. VA was worse than hand motion in 71% of the patients (n = 15). Longitudinal assessment of VA showed stability in all patients, except 1 patient who experienced deterioration over a follow-up of 44 years. Hyperopia was reported in 13 of the 17 subjects (71%) with available refraction data. Eighteen subjects had either normal fundus appearance (n = 14) or a blond fundus (n = 3), while only 4 of the eldest subjects had mild retinal pigment epithelium (RPE) atrophy (mean, 49 years; range 40-54 years). OCT data were available for 11 subjects and 4 different grades of ellipsoid zone (EZ) integrity were identified: (1) continuous/intact EZ (n = 6), (2) focally disrupted EZ (n = 2), (3) focally disrupted with RPE changes (n = 2), and (4) diffuse EZ disruption with RPE changes (n = 1). All examined subjects had stable OCT findings over the long follow-up period. Full-field ERGs showed evidence of a severe cone-rod dystrophy in 5 of 6 patients and undetectable ERGs in 1 subject. Novel genotype-phenotype correlations are also reported. CONCLUSION GUCY2D-LCA is a severe early-onset retinal dystrophy associated with very poor VA from birth. Despite the severely affected photoreceptor function, the relatively preserved photoreceptor structure based on EZ integrity until late in the disease in the majority of subjects suggests a wide therapeutic window for gene therapy trials.
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GCAP neuronal calcium sensor proteins mediate photoreceptor cell death in the rd3 mouse model of LCA12 congenital blindness by involving endoplasmic reticulum stress. Cell Death Dis 2020; 11:62. [PMID: 31980596 PMCID: PMC6981271 DOI: 10.1038/s41419-020-2255-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 01/01/2023]
Abstract
Loss-of-function mutations in the retinal degeneration 3 (RD3) gene cause inherited retinopathy with impaired rod and cone function and fast retinal degeneration in patients and in the natural strain of rd3 mice. The underlying physiopathology mechanisms are not well understood. We previously proposed that guanylate cyclase-activating proteins (GCAPs) might be key Ca2+-sensors mediating the physiopathology of this disorder, based on the demonstrated toxicity of GCAP2 when blocked in its Ca2+-free form at photoreceptor inner segments. We here show that the retinal degeneration in rd3 mice is substantially delayed by GCAPs ablation. While the number of retinal photoreceptor cells is halved in 6 weeks in rd3 mice, it takes 8 months to halve in rd3/rd3 GCAPs-/- mice. Although this substantial morphological rescue does not correlate with recovery of visual function due to very diminished guanylate cyclase activity in rd3 mice, it is very informative of the mechanisms underlying photoreceptor cell death. By showing that GCAP2 is mostly in its Ca2+-free-phosphorylated state in rd3 mice, we infer that the [Ca2+]i at rod inner segments is permanently low. GCAPs are therefore retained at the inner segment in their Ca2+-free, guanylate cyclase activator state. We show that in this conformational state GCAPs induce endoplasmic reticulum (ER) stress, mitochondrial swelling, and cell death. ER stress and mitochondrial swelling are early hallmarks of rd3 retinas preceding photoreceptor cell death, that are substantially rescued by GCAPs ablation. By revealing the involvement of GCAPs-induced ER stress in the physiopathology of Leber's congenital amaurosis 12 (LCA12), this work will aid to guide novel therapies to preserve retinal integrity in LCA12 patients to expand the window for gene therapy intervention to restore vision.
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Leber congenital amaurosis: Current genetic basis, scope for genetic testing and personalized medicine. Exp Eye Res 2019; 189:107834. [PMID: 31639339 DOI: 10.1016/j.exer.2019.107834] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 10/06/2019] [Accepted: 10/10/2019] [Indexed: 02/07/2023]
Abstract
Retinal dystrophies are one of the leading causes of pediatric congenital blindness. Leber's congenital amaurosis (LCA) encompasses one of the most severe forms of inherited retinal dystrophy responsible for early-onset childhood blindness in infancy. These are clinically characterized by nystagmus, amaurotic pupil response and markedly reduced or in most instances completely absent full-field electroretinogram. LCA exhibits immense genetic heterogeneity. With advances in next-generation genetic technologies, tremendous progress has been achieved over the last two decades in discovering genes and genetic defects leading to retinal dystrophies. Currently, 28 genes have been implicated in the pathogenesis of LCA and with initial reports of success in management with targeted gene therapy the disease has attracted a lot of research attention in the recent time. The review provides an update on genetic basis of LCA, scope for genetic testing and pharmacogenetic medicine in diagnosis and treatment of these diseases.
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28
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Cideciyan AV, Jacobson SG. Leber Congenital Amaurosis (LCA): Potential for Improvement of Vision. Invest Ophthalmol Vis Sci 2019; 60:1680-1695. [PMID: 31009524 PMCID: PMC6892385 DOI: 10.1167/iovs.19-26672] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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29
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McCullough KT, Boye SL, Fajardo D, Calabro K, Peterson JJ, Strang CE, Chakraborty D, Gloskowski S, Haskett S, Samuelsson S, Jiang H, Witherspoon CD, Gamlin PD, Maeder ML, Boye SE. Somatic Gene Editing of GUCY2D by AAV-CRISPR/Cas9 Alters Retinal Structure and Function in Mouse and Macaque. Hum Gene Ther 2019; 30:571-589. [PMID: 30358434 PMCID: PMC6534089 DOI: 10.1089/hum.2018.193] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 10/23/2018] [Indexed: 12/15/2022] Open
Abstract
Mutations in GUCY2D, the gene encoding retinal guanylate cyclase-1 (retGC1), are the leading cause of autosomal dominant cone-rod dystrophy (CORD6). Significant progress toward clinical application of gene replacement therapy for Leber congenital amaurosis (LCA) due to recessive mutations in GUCY2D (LCA1) has been made, but a different approach is needed to treat CORD6 where gain of function mutations cause dysfunction and dystrophy. The CRISPR/Cas9 gene editing system efficiently disrupts genes at desired loci, enabling complete gene knockout or homology directed repair. Here, adeno-associated virus (AAV)-delivered CRISPR/Cas9 was used specifically to edit/disrupt this gene's early coding sequence in mouse and macaque photoreceptors in vivo, thereby knocking out retGC1 expression and demonstrably altering retinal function and structure. Neither preexisting nor induced Cas9-specific T-cell responses resulted in ocular inflammation in macaques, nor did it limit GUCY2D editing. The results show, for the first time, the ability to perform somatic gene editing in primates using AAV-CRISPR/Cas9 and demonstrate the viability this approach for treating inherited retinal diseases in general and CORD6 in particular.
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Affiliation(s)
| | - Sanford L. Boye
- Department of Ophthalmology, University of Florida, Gainesville, Florida
| | - Diego Fajardo
- Department of Ophthalmology, University of Florida, Gainesville, Florida
| | - Kaitlyn Calabro
- Department of Ophthalmology, University of Florida, Gainesville, Florida
| | - James J. Peterson
- Department of Ophthalmology, University of Florida, Gainesville, Florida
| | - Christianne E. Strang
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Dibyendu Chakraborty
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama
| | | | | | | | | | | | - Paul D. Gamlin
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama
| | | | - Shannon E. Boye
- Department of Ophthalmology, University of Florida, Gainesville, Florida
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30
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Peshenko IV, Yu Q, Lim S, Cudia D, Dizhoor AM, Ames JB. Retinal degeneration 3 (RD3) protein, a retinal guanylyl cyclase regulator, forms a monomeric and elongated four-helix bundle. J Biol Chem 2019; 294:2318-2328. [PMID: 30559291 PMCID: PMC6378972 DOI: 10.1074/jbc.ra118.006106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 12/07/2018] [Indexed: 12/20/2022] Open
Abstract
Retinal degeneration 3 (RD3) protein promotes accumulation of retinal membrane guanylyl cyclase (RetGC) in the photoreceptor outer segment and suppresses RetGC activation by guanylyl cyclase-activating proteins (GCAPs). Mutations truncating RD3 cause severe congenital blindness by preventing the inhibitory binding of RD3 to the cyclase. The high propensity of RD3 to aggregate in solution has prevented structural analysis. Here, we produced a highly soluble variant of human RD3 (residues 18-160) that is monomeric and can still bind and negatively regulate RetGC. The NMR solution structure of RD3 revealed an elongated backbone structure (70 Å long and 30 Å wide) consisting of a four-helix bundle with a long unstructured loop between helices 1 and 2. The structure reveals that RD3 residues previously implicated in the RetGC binding map to a localized and contiguous area on the structure, involving a loop between helices 2 and 3 and adjacent parts of helices 3 and 4. The NMR structure of RD3 was validated by mutagenesis. Introducing Trp85 or Phe29 to replace Cys or Leu, respectively, disrupts packing in the hydrophobic core and lowers RD3's apparent affinity for RetGC1. Introducing a positive charge at the interface (Glu32 to Lys) also lowered the affinity. Conversely, introducing Val in place of Cys93 stabilized the hydrophobic core and increased the RD3 affinity for the cyclase. The NMR structure of RD3 presented here provides a structural basis for elucidating RD3-RetGC interactions relevant for normal vision or blindness.
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Affiliation(s)
- Igor V Peshenko
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027 and
| | - Qinhong Yu
- the Department of Chemistry, University of California, Davis, California 95616
| | - Sunghyuk Lim
- the Department of Chemistry, University of California, Davis, California 95616
| | - Diana Cudia
- the Department of Chemistry, University of California, Davis, California 95616
| | - Alexander M Dizhoor
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027 and
| | - James B Ames
- the Department of Chemistry, University of California, Davis, California 95616
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31
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Peshenko IV, Cideciyan AV, Sumaroka A, Olshevskaya EV, Scholten A, Abbas S, Koch KW, Jacobson SG, Dizhoor AM. A G86R mutation in the calcium-sensor protein GCAP1 alters regulation of retinal guanylyl cyclase and causes dominant cone-rod degeneration. J Biol Chem 2019; 294:3476-3488. [PMID: 30622141 DOI: 10.1074/jbc.ra118.006180] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 01/04/2019] [Indexed: 11/06/2022] Open
Abstract
The guanylyl cyclase-activating protein, GCAP1, activates photoreceptor membrane guanylyl cyclase (RetGC) in the light, when free Ca2+ concentrations decline, and decelerates the cyclase in the dark, when Ca2+ concentrations rise. Here, we report a novel mutation, G86R, in the GCAP1 (GUCA1A) gene in a family with a dominant retinopathy. The G86R substitution in a "hinge" region connecting EF-hand domains 2 and 3 in GCAP1 strongly interfered with its Ca2+-dependent activator-to-inhibitor conformational transition. The G86R-GCAP1 variant activated RetGC at low Ca2+ concentrations with higher affinity than did the WT GCAP1, but failed to decelerate the cyclase at the Ca2+ concentrations characteristic of dark-adapted photoreceptors. Ca2+-dependent increase in Trp94 fluorescence, indicative of the GCAP1 transition to its RetGC inhibiting state, was suppressed and shifted to a higher Ca2+ range. Conformational changes in G86R GCAP1 detectable by isothermal titration calorimetry (ITC) also became less sensitive to Ca2+, and the dose dependence of the G86R GCAP1-RetGC1 complex inhibition by retinal degeneration 3 (RD3) protein was shifted toward higher than normal concentrations. Our results indicate that the flexibility of the hinge region between EF-hands 2 and 3 is required for placing GCAP1-regulated Ca2+ sensitivity of the cyclase within the physiological range of intracellular Ca2+ at the expense of reducing GCAP1 affinity for the target enzyme. The disease-linked mutation of the hinge Gly86, leading to abnormally high affinity for the target enzyme and reduced Ca2+ sensitivity of GCAP1, is predicted to abnormally elevate cGMP production and Ca2+ influx in photoreceptors in the dark.
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Affiliation(s)
- Igor V Peshenko
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027
| | - Artur V Cideciyan
- the Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and
| | - Alexander Sumaroka
- the Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and
| | - Elena V Olshevskaya
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027
| | - Alexander Scholten
- the Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
| | - Seher Abbas
- the Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
| | - Karl-Wilhelm Koch
- the Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
| | - Samuel G Jacobson
- the Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and
| | - Alexander M Dizhoor
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027,
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32
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Cideciyan AV, Jacobson SG, Drack AV, Ho AC, Charng J, Garafalo AV, Roman AJ, Sumaroka A, Han IC, Hochstedler MD, Pfeifer WL, Sohn EH, Taiel M, Schwartz MR, Biasutto P, Wit WD, Cheetham ME, Adamson P, Rodman DM, Platenburg G, Tome MD, Balikova I, Nerinckx F, Zaeytijd JD, Van Cauwenbergh C, Leroy BP, Russell SR. Effect of an intravitreal antisense oligonucleotide on vision in Leber congenital amaurosis due to a photoreceptor cilium defect. Nat Med 2018; 25:225-228. [PMID: 30559420 DOI: 10.1038/s41591-018-0295-0] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/02/2018] [Indexed: 11/09/2022]
Abstract
Photoreceptor ciliopathies constitute the most common molecular mechanism of the childhood blindness Leber congenital amaurosis. Ten patients with Leber congenital amaurosis carrying the c.2991+1655A>G allele in the ciliopathy gene centrosomal protein 290 (CEP290) were treated (ClinicalTrials.gov no. NCT03140969 ) with intravitreal injections of an antisense oligonucleotide to restore correct splicing. There were no serious adverse events, and vision improved at 3 months. The visual acuity of one exceptional responder improved from light perception to 20/400.
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Affiliation(s)
- Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Arlene V Drack
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Allen C Ho
- Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jason Charng
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexandra V Garafalo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alejandro J Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ian C Han
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Maria D Hochstedler
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Wanda L Pfeifer
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Elliott H Sohn
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | | | | | | | | | | | - Peter Adamson
- ProQR Therapeutics, Leiden, the Netherlands.,UCL Institute of Ophthalmology, London, UK
| | | | | | | | - Irina Balikova
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Fanny Nerinckx
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Julie De Zaeytijd
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | | | - Bart P Leroy
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Stephen R Russell
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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33
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The regulatory role of the kinase-homology domain in receptor guanylyl cyclases: nothing 'pseudo' about it! Biochem Soc Trans 2018; 46:1729-1742. [PMID: 30420416 DOI: 10.1042/bst20180472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/08/2018] [Accepted: 10/11/2018] [Indexed: 01/05/2023]
Abstract
The availability of genome sequence information and a large number of protein structures has allowed the cataloging of genes into various families, based on their function and predicted biochemical activity. Intriguingly, a number of proteins harbor changes in the amino acid sequence at residues, that from structural elucidation, are critical for catalytic activity. Such proteins have been categorized as 'pseudoenzymes'. Here, we review the role of the pseudokinase (or kinase-homology) domain in receptor guanylyl cyclases. These are multidomain single-pass, transmembrane proteins harboring an extracellular ligand-binding domain, and an intracellular domain composed of a kinase-homology domain that regulates the activity of the associated guanylyl cyclase domain. Mutations that lie in the kinase-homology domain of these receptors are associated with human disease, and either abolish or enhance cGMP production by these receptors to alter downstream signaling events. This raises the interesting possibility that one could identify molecules that bind to the pseudokinase domain and regulate the activities of these receptors, in order to alleviate symptoms in patients harboring these mutations.
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34
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Wimberg H, Lev D, Yosovich K, Namburi P, Banin E, Sharon D, Koch KW. Photoreceptor Guanylate Cyclase ( GUCY2D) Mutations Cause Retinal Dystrophies by Severe Malfunction of Ca 2+-Dependent Cyclic GMP Synthesis. Front Mol Neurosci 2018; 11:348. [PMID: 30319355 PMCID: PMC6167591 DOI: 10.3389/fnmol.2018.00348] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/06/2018] [Indexed: 12/12/2022] Open
Abstract
Over 100 mutations in GUCY2D that encodes the photoreceptor guanylate cyclase GC-E are known to cause two major diseases: autosomal recessive Leber congenital amaurosis (arLCA) or autosomal dominant cone-rod dystrophy (adCRD) with a poorly understood mechanism at the molecular level in most cases. Only few mutations were further characterized for their enzymatic and molecular properties. GC-E activity is under control of neuronal Ca2+-sensor proteins, which is often a possible route to dysfunction. We investigated five recently-identified GC-E mutants that have been reported in patients suffering from arLCA (one large family) and adCRD/maculopathy (four families). Microsatellite analysis revealed that one of the mutations, c.2538G > C (p.K846N), occurred de novo. To better understand the mechanism by which mutations that are located in different GC-E domains develop different phenotypes, we investigated the molecular consequences of these mutations by expressing wildtype and mutant GC-E variants in HEK293 cells. Analyzing their general enzymatic behavior, their regulation by Ca2+ sensor proteins and retinal degeneration protein 3 (RD3) dimerization domain mutants (p.E841K and p.K846N) showed a shift in Ca2+-sensitive regulation by guanylate cyclase-activating proteins (GCAPs). Mutations in the cyclase catalytic domain led to a loss of enzyme function in the mutant p.P873R, but not in p.V902L. Instead, the p.V902L mutation increased the guanylate cyclase activity more than 20-fold showing a high GCAP independent activity and leading to a constitutively active mutant. This is the first mutation to be described affecting the GC-E catalytic core in a complete opposite way.
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Affiliation(s)
- Hanna Wimberg
- Department of Neuroscience, Biochemistry Group, University of Oldenburg, Oldenburg, Germany
| | - Dorit Lev
- The Rina Mor Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Keren Yosovich
- The Rina Mor Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Prasanthi Namburi
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Karl-Wilhelm Koch
- Department of Neuroscience, Biochemistry Group, University of Oldenburg, Oldenburg, Germany
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Teo KYC, Lee SY, Barathi AV, Tun SBB, Tan L, Constable IJ. Surgical Removal of Internal Limiting Membrane and Layering of AAV Vector on the Retina Under Air Enhances Gene Transfection in a Nonhuman Primate. ACTA ACUST UNITED AC 2018; 59:3574-3583. [DOI: 10.1167/iovs.18-24333] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Kelvin Yi Chong Teo
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Shu Yen Lee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Amutha Veluchamy Barathi
- Translational Pre-clinical Model Platform, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Sai Bo Bo Tun
- Translational Pre-clinical Model Platform, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Licia Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Ian Jeffery Constable
- Centre of Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Perth, Western Australia
- Department of Ophthalmology, Sir Charles Gairdner Hospital, Perth, Western Australia
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Stunkel ML, Brodie SE, Cideciyan AV, Pfeifer WL, Kennedy EL, Stone EM, Jacobson SG, Drack AV. Expanded Retinal Disease Spectrum Associated With Autosomal Recessive Mutations in GUCY2D. Am J Ophthalmol 2018; 190:58-68. [PMID: 29559409 DOI: 10.1016/j.ajo.2018.03.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 03/06/2018] [Accepted: 03/11/2018] [Indexed: 11/17/2022]
Abstract
PURPOSE GUCY2D has been associated with autosomal recessive Leber congenital amaurosis and autosomal dominant cone-rod dystrophy. This report expands the phenotype of autosomal recessive mutations to congenital night blindness, which may slowly progress to mild retinitis pigmentosa. DESIGN Retrospective case series. METHODS Multicenter study of 5 patients (3 male, 2 female). RESULTS All patients presented with night blindness since childhood. Age at referral was 9-45 years. Length of follow-up was 1-7 years. Best-corrected visual acuity at presentation ranged from 20/15 to 20/30 and at most recent visit averaged 20/25. No patient had nystagmus or high refractive error. ISCEV standard electroretinography revealed nondetectable dark-adapted dim flash responses and reduced amplitude but not electronegative dark-adapted bright flash responses with similar waveforms to the reduced-amplitude light-adapted single flash responses. The 30 Hz flicker responses were relatively preserved. Macular optical coherence tomography revealed normal lamination in 3 patients, with abnormalities in 2. Goldmann visual fields were normal at presentation in children but constricted in 1 adult. One child showed loss of midperipheral fields over time. Fundus appearance was normal in childhood; the adult had sparse bone spicule-like pigmentation. Full-field stimulus testing (FST) revealed markedly decreased retinal sensitivity to light. Dark adaptation demonstrated lack of rod-cone break. Two patients had tritanopia. All 5 had compound heterozygous mutations in GUCY2D. Three of the 5 patients harbor the Arg768Trp mutation reported in GUCY2D-associated Leber congenital amaurosis. CONCLUSIONS Autosomal recessive GUCY2D mutations may cause congenital night blindness with normal acuity and refraction, and unique electroretinography. Progression to mild retinitis pigmentosa may occur.
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Affiliation(s)
- Maria L Stunkel
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Scott E Brodie
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wanda L Pfeifer
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Elizabeth L Kennedy
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Edwin M Stone
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Arlene V Drack
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA.
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Miraldi Utz V, Pfeifer W, Longmuir SQ, Olson RJ, Wang K, Drack AV. Presentation of TRPM1-Associated Congenital Stationary Night Blindness in Children. JAMA Ophthalmol 2018; 136. [PMID: 29522070 PMCID: PMC5876850 DOI: 10.1001/jamaophthalmol.2018.0185] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
IMPORTANCE Congenital stationary night blindness (CSNB) implies a stable condition, with the major symptom being nyctalopia present at birth. Pediatric clinical presentation and the course of different genetic subtypes of CSNB have not, to our knowledge, been well described in the era of molecular genetic diagnosis. OBJECTIVE To describe the presentation and longitudinal clinical characteristics of pediatric patients with molecularly confirmed TRPM1-associated complete CSNB (cCSNB). DESIGN, SETTING, PARTICIPANTS This study was conducted at the University of Iowa from January 1, 1990, to July 1, 2015, and was a retrospective, longitudinal case series of 7 children (5 [71.4%] female) with TRPM1-associated cCSNB followed up for a mean (SD) of 11.1 (2.8) years. MAIN OUTCOMES AND MEASURES History, ophthalmologic examination findings, full-field electroretinogram (ffERG) results, full-field stimulus threshold testing results, Goldmann visual field results, optical coherence tomography results, and molecular genetic results were evaluated. Presenting symptoms and signs, the correlation of refractive error with electroretinography, and clinical evolution were analyzed. RESULTS Seven patients (5 [71.4%] female) presented early in childhood with strabismus (n = 6 [86%]), myopia (n = 5 [71%]), and/or nystagmus (n = 3 [43%]). The mean (SD) age at presentation was 8 (4) months and for receiving a diagnosis by ffERG was 7.3 years, with molecular diagnosis at 9.7 years. The mean (SD) length of follow-up was 11 (2.8) years. The best-corrected visual acuity at the most recent visit averaged 20/30 in the better-seeing eye (range, 20/20-20/60). The mean (SD) initial refraction was -2.80 (4.42) diopters (D) and the mean refraction at the most recent visit was -8.75 (3.53) D (range, -4.00 to -13.75 D), with the greatest rate of myopic shift before age 5 years. Full-field electroretinogram results were electronegative, consistent with cCSNB, without a significant change in amplitude over time. No patient or parent noted night blindness at presentation; however, subjective nyctalopia was eventually reported in 5 of 7 patients (71%). The full-field stimulus threshold testing results were moderately subnormal (-29.7 [3.8] dB; normal -59.8 [4.0] dB). Goldmann visual field results were significant for full I-4e, but constricted I-2e isopter. Eight different mutations or rare variants in TRPM1 predicted to be pathogenic were detected, with 3 novel variants. CONCLUSIONS AND RELEVANCE Children with TRPM1-associated cCSNB presented before school age with progressive myopia as well as strabismus and nystagmus (but not nyctalopia), with stable, electronegative ffERG results, mildly subnormal full-field stimulus threshold testing results, and a constricted I2e isopter on perimetry. These findings suggest that ffERG and cCSNB genetic testing should be considered for children who present with early-onset myopia, especially in the presence of strabismus and/or nystagmus, and that TRPM1-associated cCSNB is a channelopathy that may present without complaints of night blindness in childhood.
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Affiliation(s)
- Virginia Miraldi Utz
- Abrahamson Pediatric Eye Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
- Department of Ophthalmology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Wanda Pfeifer
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
- University of Iowa Institute for Vision Research, Iowa City
| | - Susannah Q. Longmuir
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
- Private practice, Nashville, Tennessee
| | - Richard John Olson
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
| | - Kai Wang
- University of Iowa Institute for Vision Research, Iowa City
- Department of Biostatistics, University of Iowa, Iowa City
| | - Arlene V. Drack
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
- University of Iowa Institute for Vision Research, Iowa City
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Sharon D, Wimberg H, Kinarty Y, Koch KW. Genotype-functional-phenotype correlations in photoreceptor guanylate cyclase (GC-E) encoded by GUCY2D. Prog Retin Eye Res 2018; 63:69-91. [DOI: 10.1016/j.preteyeres.2017.10.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/16/2017] [Accepted: 10/16/2017] [Indexed: 01/09/2023]
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Li Y, Pan Q, Gu YS. Phenotype-genotype correlation with Sanger sequencing identified retinol dehydrogenase 12 (RDH12) compound heterozygous variants in a Chinese family with Leber congenital amaurosis. J Zhejiang Univ Sci B 2018; 18:421-429. [PMID: 28471114 DOI: 10.1631/jzus.b1600156] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Leber congenital amaurosis (LCA) is a group of clinically and genetically heterogeneous retinal dystrophy. To date, 22 genes are known to be responsible for LCA, and some specific phenotypic features could provide significant prognostic information for a potential genetic etiology. This study is to identify gene variants responsible for LCA in a Chinese family using direct Sanger sequencing, with the help of phenotype-genotype correlations. METHODS A Chinese family with six members including two individuals affected with LCA was studied. All patients underwent a complete ophthalmic examination. Based on phenotype-genotype correlation, direct Sanger sequencing was performed to identify the candidate gene on all family members and normal controls. Targeted next-generation sequencing was used to exclude other known LCA genes. RESULTS By Sanger sequencing, we identified two novel missense variants in the retinol dehydrogenase 12 (RDH12) gene: a c.164C>A transversion predicting a p.T55K substitution, and a c.535C>G transversion predicting a p.H179D substitution. The two affected subjects carried both RDH12 variants, while their parents and offspring carried only one of heterozygous variants, showing complete cosegregation of the variants. The compound heterozygous variants were not present in 600 normal controls. Besides, the RDH12 variants were confirmed by targeted next-generation sequencing. CONCLUSIONS The RDH12 compound heterozygous variants might be the cause of the LCA family. Our study adds to the molecular spectrum of RDH12-related retinopathy and offers an effective example of the power of phenotype-genotype correlations in molecular diagnosis of LCA.
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Affiliation(s)
- Yun Li
- Department of Ophthalmology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Qing Pan
- Department of Ophthalmology, Zhejiang Provincial People's Hospital, Hangzhou 310014, China
| | - Yang-Shun Gu
- Department of Ophthalmology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China
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40
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López-Begines S, Plana-Bonamaisó A, Méndez A. Molecular determinants of Guanylate Cyclase Activating Protein subcellular distribution in photoreceptor cells of the retina. Sci Rep 2018; 8:2903. [PMID: 29440717 PMCID: PMC5811540 DOI: 10.1038/s41598-018-20893-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/26/2018] [Indexed: 11/10/2022] Open
Abstract
Retinal guanylate cyclase (RetGC) and guanylate cyclase activating proteins (GCAPs) play an important role during the light response in photoreceptor cells. Mutations in these proteins are linked to distinct forms of blindness. RetGC and GCAPs exert their role at the ciliary outer segment where phototransduction takes place. We investigated the mechanisms governing GCAP1 and GCAP2 distribution to rod outer segments by expressing selected GCAP1 and GCAP2 mutants as transient transgenes in the rods of GCAP1/2 double knockout mice. We show that precluding GCAP1 direct binding to RetGC (K23D/GCAP1) prevented its distribution to rod outer segments, while preventing GCAP1 activation of RetGC post-binding (W94A/GCAP1) did not. We infer that GCAP1 translocation to the outer segment strongly depends on GCAP1 binding affinity for RetGC, which points to GCAP1 requirement to bind to RetGC to be transported. We gain further insight into the distinctive regulatory steps of GCAP2 distribution, by showing that a phosphomimic at position 201 is sufficient to retain GCAP2 at proximal compartments; and that the bovine equivalent to blindness-causative mutation G157R/GCAP2 results in enhanced phosphorylation in vitro and significant retention at the inner segment in vivo, as likely contributing factors to the pathophysiology.
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Affiliation(s)
- Santiago López-Begines
- Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.,Department of Physiology, University of Barcelona School of Medicine-Bellvitge Health Science Campus, Barcelona, Spain
| | - Anna Plana-Bonamaisó
- Department of Physiology, University of Barcelona School of Medicine-Bellvitge Health Science Campus, Barcelona, Spain
| | - Ana Méndez
- Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain. .,Department of Physiology, University of Barcelona School of Medicine-Bellvitge Health Science Campus, Barcelona, Spain.
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GUCY2D Cone-Rod Dystrophy-6 Is a "Phototransduction Disease" Triggered by Abnormal Calcium Feedback on Retinal Membrane Guanylyl Cyclase 1. J Neurosci 2018; 38:2990-3000. [PMID: 29440533 DOI: 10.1523/jneurosci.2985-17.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/19/2018] [Accepted: 01/24/2018] [Indexed: 12/24/2022] Open
Abstract
The Arg838Ser mutation in retinal membrane guanylyl cyclase 1 (RetGC1) has been linked to autosomal dominant cone-rod dystrophy type 6 (CORD6). It is believed that photoreceptor degeneration is caused by the altered sensitivity of RetGC1 to calcium regulation via guanylyl cyclase activating proteins (GCAPs). To determine the mechanism by which this mutation leads to degeneration, we investigated the structure and function of rod photoreceptors in two transgenic mouse lines, 362 and 379, expressing R838S RetGC1. In both lines, rod outer segments became shorter than in their nontransgenic siblings by 3-4 weeks of age, before the eventual photoreceptor degeneration. Despite the shortening of their outer segments, the dark current of transgenic rods was 1.5-2.2-fold higher than in nontransgenic controls. Similarly, the dim flash response amplitude in R838S+ rods was larger, time to peak was delayed, and flash sensitivity was increased, all suggesting elevated dark-adapted free cGMP in transgenic rods. In rods expressing R838S RetGC1, dark-current noise increased and the exchange current, detected after a saturating flash, became more pronounced. These results suggest disrupted Ca2+ phototransduction feedback and abnormally high free-Ca2+ concentration in the outer segments. Notably, photoreceptor degeneration, which typically occurred after 3 months of age in R838S RetGC1 transgenic mice in GCAP1,2+/+ or GCAP1,2+/- backgrounds, was prevented in GCAP1,2-/- mice lacking Ca2+ feedback to guanylyl cyclase. In summary, the dysregulation of guanylyl cyclase in RetGC1-linked CORD6 is a "phototransduction disease," which means it is associated with increased free-cGMP and Ca2+ levels in photoreceptors.SIGNIFICANCE STATEMENT In a mouse model expressing human membrane guanylyl cyclase 1 (RetGC1, GUCY2D), a mutation associated with early progressing congenital blindness, cone-rod dystrophy type 6 (CORD6), deregulates calcium-sensitive feedback of phototransduction to the cyclase mediated by guanylyl cyclase activating proteins (GCAPs), which are calcium-sensor proteins. The abnormal calcium sensitivity of the cyclase increases cGMP-gated dark current in the rod outer segments, reshapes rod photoresponses, and triggers photoreceptor death. This work is the first to demonstrate a direct physiological effect of GUCY2D CORD6-linked mutation on photoreceptor physiology in vivo It also identifies the abnormal regulation of the cyclase by calcium-sensor proteins as the main trigger for the photoreceptor death.
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Tikidji-Hamburyan A, Reinhard K, Storchi R, Dietter J, Seitter H, Davis KE, Idrees S, Mutter M, Walmsley L, Bedford RA, Ueffing M, Ala-Laurila P, Brown TM, Lucas RJ, Münch TA. Rods progressively escape saturation to drive visual responses in daylight conditions. Nat Commun 2017; 8:1813. [PMID: 29180667 PMCID: PMC5703729 DOI: 10.1038/s41467-017-01816-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 10/18/2017] [Indexed: 12/21/2022] Open
Abstract
Rod and cone photoreceptors support vision across large light intensity ranges. Rods, active under dim illumination, are thought to saturate at higher (photopic) irradiances. The extent of rod saturation is not well defined; some studies report rod activity well into the photopic range. Using electrophysiological recordings from retina and dorsal lateral geniculate nucleus of cone-deficient and visually intact mice, we describe stimulus and physiological factors that influence photopic rod-driven responses. We find that rod contrast sensitivity is initially strongly reduced at high irradiances, but progressively recovers to allow responses to moderate contrast stimuli. Surprisingly, rods recover faster at higher light levels. A model of rod phototransduction suggests that phototransduction gain adjustments and bleaching adaptation underlie rod recovery. Consistently, exogenous chromophore reduces rod responses at bright background. Thus, bleaching adaptation renders mouse rods responsive to modest contrast at any irradiance. Paradoxically, raising irradiance across the photopic range increases the robustness of rod responses. Rod photoreceptors are thought to be saturated under bright light. Here, the authors describe the physiological parameters that mediate response saturation of rod photoreceptors in mouse retina, and show that rods can drive visual responses in photopic conditions.
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Affiliation(s)
- Alexandra Tikidji-Hamburyan
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany.,Department of Neurosurgery and Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, 94305-4085, USA
| | - Katja Reinhard
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany.,Visual Circuits Laboratory, Neuro-Electronics Research Flanders, IMEC, KU Leuven and VIB, 3001, Leuven, Belgium
| | - Riccardo Storchi
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Johannes Dietter
- Institute for Ophthalmic Research, Department of Ophthalmology, University of Tübingen, 72076, Tübingen, Germany
| | - Hartwig Seitter
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany.,Institute of Pharmacy, Department of Pharmacology and Toxicology, University of Innsbruck, A-6020, Innsbruck, Austria
| | - Katherine E Davis
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Saad Idrees
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany
| | - Marion Mutter
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany.,International Max Planck Research School, University of Tübingen, 72074, Tübingen, Germany
| | - Lauren Walmsley
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Robert A Bedford
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.,Stryker Imorphics, Worthington House, Towers Business Park, Wilmslow Road, Manchester, M20 2HJ, UK
| | - Marius Ueffing
- Institute for Ophthalmic Research, Department of Ophthalmology, University of Tübingen, 72076, Tübingen, Germany
| | - Petri Ala-Laurila
- Department of Biosciences, University of Helsinki, 00014, Helsinki, Finland.,Department of Neuroscience and Biomedical Engineering (NBE), Aalto University School of Science and Technology, 00076, Espoo, Finland
| | - Timothy M Brown
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Robert J Lucas
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.
| | - Thomas A Münch
- Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, 72076, Tübingen, Germany. .,Institute for Ophthalmic Research, Department of Ophthalmology, University of Tübingen, 72076, Tübingen, Germany.
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Thompson JA, De Roach JN, McLaren TL, Montgomery HE, Hoffmann LH, Campbell IR, Chen FK, Mackey DA, Lamey TM. The genetic profile of Leber congenital amaurosis in an Australian cohort. Mol Genet Genomic Med 2017; 5:652-667. [PMID: 29178642 PMCID: PMC5702575 DOI: 10.1002/mgg3.321] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 12/21/2022] Open
Abstract
Background Leber congenital amaurosis (LCA) is a severe visual impairment responsible for infantile blindness, representing ~5% of all inherited retinal dystrophies. LCA encompasses a group of heterogeneous disorders, with 24 genes currently implicated in pathogenesis. Such clinical and genetic heterogeneity poses great challenges for treatment, with personalized therapies anticipated to be the best treatment candidates. Unraveling the individual genetic etiology of disease is a prerequisite for personalized therapies, and could identify potential treatment candidates, inform patient management, and discriminate syndromic forms of disease. Methods We have genetically analyzed 45 affected and 82 unaffected individuals from 34 unrelated LCA pedigrees using predominantly next‐generation sequencing and Array CGH technology. Results We present the molecular findings for an Australian LCA cohort, sourced from the Australian Inherited Retinal Disease Registry & DNA Bank. CEP290 and GUCY2D mutations, each represent 19% of unrelated LCA cases, followed by NMNAT1 (12%). Genetic subtypes were consistent with other reports, and were resolved in 90% of this cohort. Conclusion The high resolution rate achieved, equivalent to recent findings using whole exome/genome sequencing, reflects the progression from hypothesis (LCA Panel) to non‐hypothesis (RD Panel) testing and, coupled with Array CGH analysis, is a highly effective first‐tier test for LCA.
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Affiliation(s)
- Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - John N De Roach
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia, Australia
| | - Terri L McLaren
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Hannah E Montgomery
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Ling H Hoffmann
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Isabella R Campbell
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Fred K Chen
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia, Australia.,Lions Eye Institute, Nedlands, Western Australia, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - David A Mackey
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia, Australia.,Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Tina M Lamey
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia, Australia
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Charng J, Jacobson SG, Heon E, Roman AJ, McGuigan DB, Sheplock R, Kosyk MS, Swider M, Cideciyan AV. Pupillary Light Reflexes in Severe Photoreceptor Blindness Isolate the Melanopic Component of Intrinsically Photosensitive Retinal Ganglion Cells. Invest Ophthalmol Vis Sci 2017; 58:3215-3224. [PMID: 28660274 PMCID: PMC5490362 DOI: 10.1167/iovs.17-21909] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose Pupillary light reflex (PLR) is driven by outer retinal photoreceptors and by melanopsin-expressing intrinsically photosensitive retinal ganglion cells of the inner retina. To isolate the melanopic component, we studied patients with severe vision loss due to Leber congenital amaurosis (LCA) caused by gene mutations acting on the outer retina. Methods Direct PLR was recorded in LCA patients (n = 21) with known molecular causation and severe vision loss. Standard stimuli (2.5 log scot-cd.m−2; ∼13 log quanta.cm−2.s−1; achromatic full-field) with 0.1- or 5-second duration were used in all patients. Additional recordings were performed with higher luminance (3.9 log scot-cd.m−2) in a subset of patients. Results The LCA patients showed no detectable PLR to the standard stimulus with short duration. With longer-duration stimuli, a PLR was detectable in the majority (18/21) of patients. The latency of the PLR was 2.8 ± 1.3 seconds, whereas normal latency was 0.19 ± 0.02 seconds. Peak contraction amplitude in patients was 1.1 ± 0.9 mm at 6.2 ± 2.3 seconds, considerably different from normal amplitude of 4.2 ± 0.4 mm at 3.0 ± 0.4 seconds. Recordings with higher luminance demonstrated that PLRs in severe LCA could also be evoked with short-duration stimuli. Conclusions The PLR in severe LCA patients likely represents the activation of the melanopic circuit in isolation from rod and cone input. Knowledge of the properties of the human melanopic PLR allows not only comparison to those in animal models but also serves to define the fidelity of postretinal transmission in clinical trials targeting patients with no outer retinal function.
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Affiliation(s)
- Jason Charng
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Alejandro J Roman
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - David B McGuigan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Rebecca Sheplock
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Mychajlo S Kosyk
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Malgorzata Swider
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Kumaran N, Moore AT, Weleber RG, Michaelides M. Leber congenital amaurosis/early-onset severe retinal dystrophy: clinical features, molecular genetics and therapeutic interventions. Br J Ophthalmol 2017; 101:1147-1154. [PMID: 28689169 PMCID: PMC5574398 DOI: 10.1136/bjophthalmol-2016-309975] [Citation(s) in RCA: 195] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/26/2017] [Accepted: 04/30/2017] [Indexed: 12/29/2022]
Abstract
Leber congenital amaurosis (LCA) and early-onset severe retinal dystrophy (EOSRD) are both genetically and phenotypically heterogeneous, and characterised clinically by severe congenital/early infancy visual loss, nystagmus, amaurotic pupils and markedly reduced/absent full-field electroretinograms. The vast genetic heterogeneity of inherited retinal disease has been established over the last 10 - 20 years, with disease-causing variants identified in 25 genes to date associated with LCA/EOSRD, accounting for 70–80% of cases, with thereby more genes yet to be identified. There is now far greater understanding of the structural and functional associations seen in the various LCA/EOSRD genotypes. Subsequent development/characterisation of LCA/EOSRD animal models has shed light on the underlying pathogenesis and allowed the demonstration of successful rescue with gene replacement therapy and pharmacological intervention in multiple models. These advancements have culminated in more than 12 completed, ongoing and anticipated phase I/II and phase III gene therapy and pharmacological human clinical trials. This review describes the clinical and genetic characteristics of LCA/EOSRD and the differential diagnoses to be considered. We discuss in further detail the diagnostic clinical features, pathophysiology, animal models and human treatment studies and trials, in the more common genetic subtypes and/or those closest to intervention.
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Affiliation(s)
- Neruban Kumaran
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,University of California San Francisco, San Francisco CA, California, USA
| | - Richard G Weleber
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Jacobson SG, Cideciyan AV, Sumaroka A, Roman AJ, Charng J, Lu M, Choudhury S, Schwartz SB, Heon E, Fishman GA, Boye SE. Defining Outcomes for Clinical Trials of Leber Congenital Amaurosis Caused by GUCY2D Mutations. Am J Ophthalmol 2017; 177:44-57. [PMID: 28212877 DOI: 10.1016/j.ajo.2017.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 11/19/2022]
Abstract
PURPOSE To determine outcome measures for a clinical trial of Leber congenital amaurosis (LCA) associated with mutations in the GUCY2D gene. DESIGN Retrospective observational case series. METHODS Twenty-eight patients with GUCY2D-LCA (aged 2-59 years) were studied clinically and with chromatic full-field sensitivity testing (FST), optical coherence tomography (OCT), pupillometry, and the NEI Visual Function Questionnaire (VFQ). RESULTS FST permitted quantitation of cone and rod sensitivity in these patients with severe visual impairment. For most patients, the degree of rod and cone sensitivity losses showed a relationship, thereby providing an opportunity to divide patients into cohorts by severity of rod and cone dysfunction. OCT analyses indicated that retinal structure could be used not only as an objective safety measure but also as an exploratory efficacy outcome. A foveal bulge was not present in 67% of patients. The intensity of inner segment/outer segment (ellipsoid zone line) reflectivity was reduced significantly at the fovea and in the rod-dense superior retina. Based on OCT and FST parameters, most patients had dissociation of structure and function. Abnormal pupillometry sensitivity in the majority of GUCY2D-LCA patients provided another objective efficacy outcome. NEI VFQ scores showed a similar range of findings to those of other severe retinal diseases. CONCLUSION Conventional outcome measures, such as visual acuity and the NEI VFQ, will need to be complemented by methods more specific to this GUCY2D-LCA population. Any therapeutic strategy should determine if there is an effect on rod as well as cone function and structure. FST provides a photoreceptor-based subjective outcome; and OCT in 2 retinal regions, fovea and superior retina, can assess photoreceptor structure. A change in the relationship of structure and function away from baseline becomes evidence of efficacy.
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Affiliation(s)
- Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Alejandro J Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jason Charng
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Monica Lu
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Shreyasi Choudhury
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Sharon B Schwartz
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, Program of Genetics and Genomic Biology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Gerald A Fishman
- Pangere Center for Hereditary Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois
| | - Shannon E Boye
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
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Diagnostic and Therapeutic Challenges. Retina 2017; 37:1008-1017. [DOI: 10.1097/iae.0000000000001212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Aguirre GK, Butt OH, Datta R, Roman AJ, Sumaroka A, Schwartz SB, Cideciyan AV, Jacobson SG. Postretinal Structure and Function in Severe Congenital Photoreceptor Blindness Caused by Mutations in the GUCY2D Gene. Invest Ophthalmol Vis Sci 2017; 58:959-973. [PMID: 28403437 PMCID: PMC5308769 DOI: 10.1167/iovs.16-20413] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose To examine how severe congenital blindness resulting from mutations of the GUCY2D gene alters brain structure and function, and to relate these findings to the notable preservation of retinal architecture in this form of Leber congenital amaurosis (LCA). Methods Six GUCY2D-LCA patients (ages 20–46) were studied with optical coherence tomography of the retina and multimodal magnetic resonance imaging (MRI) of the brain. Measurements from this group were compared to those obtained from populations of normally sighted controls and people with congenital blindness of a variety of causes. Results Patients with GUCY2D-LCA had preservation of the photoreceptors, ganglion cells, and nerve fiber layer. Despite this, visual function in these patients ranged from 20/160 acuity to no light perception, and functional MRI responses to light stimulation were attenuated and restricted. This severe visual impairment was reflected in substantial thickening of the gray matter layer of area V1, accompanied by an alteration of resting-state correlations within the occipital lobe, similar to a comparison group of congenitally blind people with structural damage to the retina. In contrast to the comparison blind population, however, the GUCY2D-LCA group had preservation of the size of the optic chiasm, and the fractional anisotropy of the optic radiations as measured with diffusion tensor imaging was also normal. Conclusions These results identify dissociable effects of blindness upon the visual pathway. Further, the relatively intact postgeniculate white matter pathway in GUCY2D-LCA is encouraging for the prospect of recovery of visual function with gene augmentation therapy.
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Affiliation(s)
- Geoffrey K Aguirre
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Omar H Butt
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Ritobrato Datta
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alejandro J Roman
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alexander Sumaroka
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Sharon B Schwartz
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Artur V Cideciyan
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Samuel G Jacobson
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Correction of Monogenic and Common Retinal Disorders with Gene Therapy. Genes (Basel) 2017; 8:genes8020053. [PMID: 28134823 PMCID: PMC5333042 DOI: 10.3390/genes8020053] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/19/2017] [Indexed: 11/16/2022] Open
Abstract
The past decade has seen major advances in gene-based therapies, many of which show promise for translation to human disease. At the forefront of research in this field is ocular disease, as the eye lends itself to gene-based interventions due to its accessibility, relatively immune-privileged status, and ability to be non-invasively monitored. A landmark study in 2001 demonstrating successful gene therapy in a large-animal model for Leber congenital amaurosis set the stage for translation of these strategies from the bench to the bedside. Multiple clinical trials have since initiated for various retinal diseases, and further improvements in gene therapy techniques have engendered optimism for alleviating inherited blinding disorders. This article provides an overview of gene-based strategies for retinal disease, current clinical trials that engage these strategies, and the latest techniques in genome engineering, which could serve as the next frontline of therapeutic interventions.
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Boye SL, Olshevskaya EV, Peshenko IV, McCullough KT, Boye SE, Dizhoor AM. Functional study of two biochemically unusual mutations in GUCY2D Leber congenital amaurosis expressed via adenoassociated virus vector in mouse retinas. Mol Vis 2016; 22:1342-1351. [PMID: 27881908 PMCID: PMC5108460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/08/2016] [Indexed: 11/03/2022] Open
Abstract
PURPOSE To test, in living photoreceptors, two mutations, S248W and R1091x, in the GUCY2D gene linked to Leber congenital amaurosis 1 (LCA1) that fail to inactivate the catalytic activity of a heterologously expressed retinal membrane guanylyl cyclase 1 (RetGC1). METHODS GUC2YD cDNA constructs coding for wild-type human (hWT), R1091x, and S248W GUCY2D under the control of the human rhodopsin kinase promoter were expressed in Gucy2e-/-Gucy2f-/- knockout (GCdKO) mouse retinas, which lack endogenous RetGC activity. The constructs were delivered via subretinally injected adenoassociated virus (AAV) vector in one eye, leaving the opposite eye as the non-injected negative control. After testing with electroretinography (ERG), the retinas extracted from the AAV-treated and control eyes were used in guanylyl cyclase activity assays, immunoblotting, and anti-RetGC1 immunofluorescence staining. RESULTS Cyclase activity in retinas treated with either hWT or R1091x GUCY2D transgenes was similar but was undetectable in the S248W GUCY2D-treated retinas, which starkly contrasts their relative activities when heterologously expressed in human embryonic kidney (HEK293) cells. Rod and cone ERGs, absent in GCdKO, appeared in the hWT and R1091x GUCY2D-injected eyes, while the S248W mutant failed to restore scotopic ERG response and enabled only rudimentary photopic ERG response. The hWT and R1091x GUCY2D immunofluorescence was robust in the rod and cone outer segments, whereas the S248W was detectable only in the sparse cone outer segments and sporadic photoreceptor cell bodies. Robust RetGC1 expression was detected with immunoblotting in the hWT and R1091x-treated retinas but was marginal at best in the S248W GUCY2D retinas, despite the confirmed presence of the S248W GUCY2D transcripts. CONCLUSIONS The phenotype of S248W GUCY2D in living retinas did not correlate with the previously described normal biochemical activity of this mutant when heterologously expressed in non-photoreceptor cell culture. This result suggests that the S248W mutation contributes to LCA1 by hampering the expression, processing, and/or cellular transport of GUCY2D, rather than its enzymatic properties. In contrast, the effective restoration of rod and cone function by R1091x GUCY2D is paradoxical and does not explain the severe loss of vision typical for LCA1 associated with that mutant allele.
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Affiliation(s)
- Sanford L. Boye
- Department of Ophthalmology, University of Florida, Gainesville, FL
| | | | - Igor V. Peshenko
- Pennsylvania College of Optometry, Salus University, Elkins Park, PA
| | | | - Shannon E. Boye
- Department of Ophthalmology, University of Florida, Gainesville, FL
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