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Kwan JT, Ramsey DJ. Multimodal image alignment aids in the evaluation and monitoring of sector retinitis pigmentosa. Ophthalmic Genet 2023; 44:93-102. [PMID: 35769018 DOI: 10.1080/13816810.2022.2092755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE To present a semi-automated method of image alignment to aid in monitoring the progression of inherited retinal degenerations (IRDs). RESULTS A 22-year-old woman presented with nyctalopia and a family history of retinitis pigmentosa (RP), but with no prior genetic testing. Fundus examination showed a sectoral retinal degeneration involving the inferior and nasal retina with rare, pigmented deposits. Goldmann kinetic perimetry demonstrated corresponding superotemporal visual field defects. The best-corrected visual acuity was 20/20 in both eyes. Multimodal imaging delineated geographically restricted peripheral retinal degeneration extending to the inferior edge of the macula. Central visual function remained intact with normal multifocal electroretinography findings. Optical coherence tomography (OCT) through the leading edge of the retinal degeneration confirmed loss of the photoreceptor layer and associated retinal pigment epithelium. In the region of retinal degeneration, loss of vascular flow density was noted on optical coherence tomography angiography (OCTA). Genetic testing identified a pathologic sequence variant in RHO (c.68C>A, p.Pro23His), confirming autosomal dominant sector retinitis pigmentosa (SRP). Image alignment allowed for precise measurement of the progression of SRP over a period of 18 months. CONCLUSION SRP is a rare subtype of RP characterized by focal, typically inferior and nasal, retinal degeneration of the peripheral retina. Although the onset and extent of peripheral retinal degeneration varies, compared with RP, SRP typically progresses more slowly to involve the macula. In this report, we highlight the utility of image registration and alignment to aid in monitoring disease progression in IRDs by means of multimodal imaging.
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Affiliation(s)
- James T Kwan
- Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, USA.,Department of Surgery, Division of Ophthalmology, Lahey Hospital & Medical Center, Burlington, Massachusetts, USA
| | - David J Ramsey
- Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, USA.,Department of Surgery, Division of Ophthalmology, Lahey Hospital & Medical Center, Burlington, Massachusetts, USA
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2
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Fitzpatrick MJ, Kerschensteiner D. Homeostatic plasticity in the retina. Prog Retin Eye Res 2022; 94:101131. [PMID: 36244950 DOI: 10.1016/j.preteyeres.2022.101131] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 02/07/2023]
Abstract
Vision begins in the retina, whose intricate neural circuits extract salient features of the environment from the light entering our eyes. Neurodegenerative diseases of the retina (e.g., inherited retinal degenerations, age-related macular degeneration, and glaucoma) impair vision and cause blindness in a growing number of people worldwide. Increasing evidence indicates that homeostatic plasticity (i.e., the drive of a neural system to stabilize its function) can, in principle, preserve retinal function in the face of major perturbations, including neurodegeneration. Here, we review the circumstances and events that trigger homeostatic plasticity in the retina during development, sensory experience, and disease. We discuss the diverse mechanisms that cooperate to compensate and the set points and outcomes that homeostatic retinal plasticity stabilizes. Finally, we summarize the opportunities and challenges for unlocking the therapeutic potential of homeostatic plasticity. Homeostatic plasticity is fundamental to understanding retinal development and function and could be an important tool in the fight to preserve and restore vision.
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3
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Lewin AS, Smith WC. Gene Therapy for Rhodopsin Mutations. Cold Spring Harb Perspect Med 2022; 12:a041283. [PMID: 35940643 PMCID: PMC9435570 DOI: 10.1101/cshperspect.a041283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mutations in RHO, the gene for rhodopsin, account for a large fraction of autosomal-dominant retinitis pigmentosa (adRP). Patients fall into two clinical classes, those with early onset, pan retinal photoreceptor degeneration, and those who experience slowly progressive disease. The latter class of patients are candidates for photoreceptor-directed gene therapy, while former may be candidates for delivery of light-responsive proteins to interneurons or retinal ganglion cells. Gene therapy for RHO adRP may be targeted to the mutant gene at the DNA or RNA level, while other therapies preserve the viability of photoreceptors without addressing the underlying mutation. Correcting the RHO gene and replacing the mutant RNA show promise in animal models, while sustaining viable photoreceptors has the potential to delay the loss of central vision and may preserve photoreceptors for gene-directed treatments.
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Affiliation(s)
- Alfred S Lewin
- Departments of Molecular Genetics and Microbiology and Ophthalmology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
| | - W Clay Smith
- Departments of Molecular Genetics and Microbiology and Ophthalmology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
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Picarazzi F, Manetti F, Marigo V, Mori M. Conformational insights into the C-terminal mutations of human rhodopsin in retinitispigmentosa. J Mol Graph Model 2021; 110:108076. [PMID: 34798368 DOI: 10.1016/j.jmgm.2021.108076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 10/19/2022]
Abstract
Rhodopsin is a light-sensitive transmembrane receptor involved in the visual transduction cascade. Among the several rhodopsin mutations related to retinitis pigmentosa (RP), those affecting the C-terminal VAPA-COOH motif that is implicated in rhodopsin trafficking from the Golgi to the rod outer segment are notably associated with more aggressive RP forms. However, molecular reasons for defective rhodopsin signaling due to VAPA-COOH mutations, which might include steric hindrance, physicochemical features and structural determinants, are yet unknown, thus limiting further drug design approaches. In this work, clinically relevant rhodopsin mutations at the P347 site within the VAPA-COOH motif were investigated by molecular dynamics (MD) simulations and compared to the wild-type (WT) system. In agreement with experimental evidence, conformational fluctuations of the intrinsically disordered C-terminal tail of WT and mutant rhodopsin were found not to affect the overall structure of the transmembrane domain, including binding to the retinal cofactor. The WT VAPA-COOH motif adopts a unique conformation that is not found in pathological mutants, suggesting that structural features could better explain the pathogenicity of P347 rhodopsin mutants than physicochemical or steric determinants. These results were confirmed by MD simulations in both membrane-embedded full-length opsin and membrane-free C-terminal deca-peptides, these latter becoming very useful and small-size model systems for further investigations of rhodopsin C-terminal mutations. Structural details elucidated in this work might facilitate the understanding of the pathological mechanisms of this class of rhodopsin mutants, which will be instrumental to the development of new therapeutic strategies.
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Affiliation(s)
- Francesca Picarazzi
- Department of Biotechnology, Chemistry and Pharmacy, "Department of Excellence 2018-2022", University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Fabrizio Manetti
- Department of Biotechnology, Chemistry and Pharmacy, "Department of Excellence 2018-2022", University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi, 287, 41125 Modena, Italy
| | - Mattia Mori
- Department of Biotechnology, Chemistry and Pharmacy, "Department of Excellence 2018-2022", University of Siena, Via Aldo Moro 2, 53100 Siena, Italy.
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5
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Massengill MT, Lewin AS. Gene Therapy for Rhodopsin-associated Autosomal Dominant Retinitis Pigmentosa. Int Ophthalmol Clin 2021; 61:79-96. [PMID: 34584046 PMCID: PMC8478325 DOI: 10.1097/iio.0000000000000383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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6
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Metabolic and Redox Signaling of the Nucleoredoxin-Like-1 Gene for the Treatment of Genetic Retinal Diseases. Int J Mol Sci 2020; 21:ijms21051625. [PMID: 32120883 PMCID: PMC7084304 DOI: 10.3390/ijms21051625] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
The loss of cone photoreceptor function in retinitis pigmentosa (RP) severely impacts the central and daily vision and quality of life of patients affected by this disease. The loss of cones follows the degeneration of rods, in a manner independent of the causing mutations in numerous genes associated with RP. We have explored this phenomenon and proposed that the loss of rods triggers a reduction in the expression of rod-derived cone viability factor (RdCVF) encoded by the nucleoredoxin-like 1 (NXNL1) gene which interrupts the metabolic and redox signaling between rods and cones. After providing scientific evidence supporting this mechanism, we propose a way to restore this lost signaling and prevent the cone vision loss in animal models of RP. We also explain how we could restore this signaling to prevent cone vision loss in animal models of the disease and how we plan to apply this therapeutic strategy by the administration of both products of NXNL1 encoding the trophic factor RdCVF and the thioredoxin enzyme RdCVFL using an adeno-associated viral vector. We describe in detail all the steps of this translational program, from the design of the drug, its production, biological validation, and analytical and preclinical qualification required for a future clinical trial that would, if successful, provide a treatment for this incurable disease.
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Sun LW, Johnson RD, Langlo CS, Cooper RF, Razeen MM, Russillo MC, Dubra A, Connor TB, Han DP, Pennesi ME, Kay CN, Weinberg DV, Stepien KE, Carroll J. Assessing Photoreceptor Structure in Retinitis Pigmentosa and Usher Syndrome. Invest Ophthalmol Vis Sci 2017; 57:2428-42. [PMID: 27145477 PMCID: PMC5089122 DOI: 10.1167/iovs.15-18246] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose The purpose of this study was to examine cone photoreceptor structure in retinitis pigmentosa (RP) and Usher syndrome using confocal and nonconfocal split-detector adaptive optics scanning light ophthalmoscopy (AOSLO). Methods Nineteen subjects (11 RP, 8 Usher syndrome) underwent ophthalmic and genetic testing, spectral-domain optical coherence tomography (SD-OCT), and AOSLO imaging. Split-detector images obtained in 11 subjects (7 RP, 4 Usher syndrome) were used to assess remnant cone structure in areas of altered cone reflectivity on confocal AOSLO. Results Despite normal interdigitation zone and ellipsoid zone appearance on OCT, foveal and parafoveal cone densities derived from confocal AOSLO images were significantly lower in Usher syndrome compared with RP. This was due in large part to an increased prevalence of non-waveguiding cones in the Usher syndrome retina. Although significantly correlated to best-corrected visual acuity and foveal sensitivity, cone density can decrease by nearly 38% before visual acuity becomes abnormal. Aberrantly waveguiding cones were noted within the transition zone of all eyes and corresponded to intact inner segment structures. These remnant cones decreased in density and increased in diameter across the transition zone and disappeared with external limiting membrane collapse. Conclusions Foveal cone density can be decreased in RP and Usher syndrome before visible changes on OCT or a decline in visual function. Thus, AOSLO imaging may allow more sensitive monitoring of disease than current methods. However, confocal AOSLO is limited by dependence on cone waveguiding, whereas split-detector AOSLO offers unambiguous and quantifiable visualization of remnant cone inner segment structure. Confocal and split-detector thus offer complementary insights into retinal pathology.
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Affiliation(s)
- Lynn W Sun
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Ryan D Johnson
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Christopher S Langlo
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Robert F Cooper
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin, United States
| | - Moataz M Razeen
- Alexandria Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Madia C Russillo
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Alfredo Dubra
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 2Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 3Department of Biomedical Engineering, Ma
| | - Thomas B Connor
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Dennis P Han
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Christine N Kay
- Vitreo Retinal Associates, Gainesville, Florida, United States
| | - David V Weinberg
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Kimberly E Stepien
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Joseph Carroll
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 2Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 3Department of Biomedical Engineering, Ma
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Funatogawa C, Szundi I, Kliger DS. A Comparison between the Photoactivation Kinetics of Human and Bovine Rhodopsins. Biochemistry 2016; 55:7005-7013. [DOI: 10.1021/acs.biochem.6b00953] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chie Funatogawa
- Department of Chemistry and
Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Istvan Szundi
- Department of Chemistry and
Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - David S. Kliger
- Department of Chemistry and
Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
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Jacobson SG, McGuigan DB, Sumaroka A, Roman AJ, Gruzensky ML, Sheplock R, Palma J, Schwartz SB, Aleman TS, Cideciyan AV. Complexity of the Class B Phenotype in Autosomal Dominant Retinitis Pigmentosa Due to Rhodopsin Mutations. Invest Ophthalmol Vis Sci 2016; 57:4847-4858. [PMID: 27654411 PMCID: PMC5032913 DOI: 10.1167/iovs.16-19890] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose Previously, patients with RHO mutations and a class A phenotype were found to have severe early-onset loss of rod function, whereas patients with a class B phenotype retained rod function at least in certain retinal regions. Here class B patients were studied at different disease stages to understand the topographic details of the phenotype in preparation for therapies of this regionalized retinopathy. Methods A cohort of patients with RHO mutations and class B phenotype (n = 28; ages 10–80 years) were studied with rod and cone perimetry and optical coherence tomography (OCT). Results At least three components of the phenotype were identified in these cross-sectional studies. Patients could have hemifield dysfunction, pericentral loss of function, or a diffuse rod sensitivity loss across the visual field. Combinations of these different patterns were also found. Colocalized photoreceptor layer thicknesses were in agreement with the psychophysical results. Conclusions These disorders with regional retinal variation of severity require pre-evaluations before enrollment into clinical trials to seek answers to questions about where in the retina would be appropriate to deliver focal treatments, and, for retina-wide treatment strategies, where in the retina should be monitored for therapeutic efficacy (or safety).
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Affiliation(s)
- Samuel G Jacobson
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - David B McGuigan
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alexander Sumaroka
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alejandro J Roman
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Michaela L Gruzensky
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Rebecca Sheplock
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Judy Palma
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Sharon B Schwartz
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Tomas S Aleman
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Artur V Cideciyan
- Scheie Eye Institute Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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