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Li X. lncRNA MALAT1 promotes diabetic retinopathy by upregulating PDE6G via miR-378a-3p. Arch Physiol Biochem 2024; 130:119-127. [PMID: 34674599 DOI: 10.1080/13813455.2021.1985144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/06/2021] [Accepted: 09/20/2021] [Indexed: 10/20/2022]
Abstract
Diabetic retinopathy (DR) is the main cause of adult insomnia, which causes certain social and economic pressure. This research was to investigate the role and regulatory mechanisms of MALAT1, miR-378a-3p and PDE6g in retinal microvascular endothelial cells (RMECs) under high glucose (HG). MALAT1, Mir-378a-3p and PDE6G expressions level were detected by qRT-PCR and Western blot. The proliferation, Bax and Bcl-2 protein expression of RMECs were detected by CCK-8 and western blot. The target relationships of MALAT1, miR-378a-3p and PDE6G were determined by bioinformatics analysis, dual-luciferase reporter gene, RIP and RNA pull-down assay. HG enhanced the expression of MALAT1 and PDE6G, and inhibited the expression of miR-378a-3p. Overexpression of MALAT1 promotes the proliferation of RMECs and inhibits apoptosis under HG condition. MALAT1 competitively adsorbed miR-378a-3p, which targeted PDE6G. Data reveal that MALAT1/miR-378a-3p/PDE6G signal axis restrain the apoptosis of RMECs under HG. This finding may help to delay the development of DR.
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Affiliation(s)
- Xiaoxia Li
- Department of Ophthalmology, Wuhan Third Hospital, Wuhan, Hubei, China
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2
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Sukkar B, Oktay L, Sahaboglu A, Moayedi A, Zenouri S, Al-Maghout T, Cantó A, Miranda M, Durdagi S, Hosseinzadeh Z. Inhibition of altered Orai1 channels in Müller cells protects photoreceptors in retinal degeneration. Glia 2023; 71:2511-2526. [PMID: 37533369 DOI: 10.1002/glia.24429] [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: 12/23/2022] [Revised: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 08/04/2023]
Abstract
The expressions of ion channels by Müller glial cells (MGCs) may change in response to various retinal pathophysiological conditions. There remains a gap in our understanding of MGCs' responses to photoreceptor degeneration towards finding therapies. The study explores how an inhibition of store-operated Ca2+ entry (SOCE) and its major component, Orai1 channel, in MGCs protects photoreceptors from degeneration. The study revealed increased Orai1 expression in the MGCs of retinal degeneration 10 (rd10) mice. Enhanced expression of oxidative stress markers was confirmed as a crucial pathological mechanism in rd10 retina. Inducing oxidative stress in rat MGCs resulted in increasing SOCE and Ca2+ release-activated Ca2+ (CRAC) currents. SOCE inhibition by 2-Aminoethoxydiphenyl borate (2-APB) protected photoreceptors in degenerated retinas. Finally, molecular simulations proved the structural and dynamical features of 2-APB to the target structure Orai1. Our results provide new insights into the physiology of MGCs regarding retinal degeneration and shed a light on SOCE and Orai1 as new therapeutic targets.
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Affiliation(s)
- Basma Sukkar
- Paul Flechsig Institute, Centre of Neuropathology and Brain Research, University of Leipzig, Leipzig, Germany
| | - Lalehan Oktay
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University, Istanbul, Turkey
| | - Ayse Sahaboglu
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University, Tübingen, Germany
| | - Aylin Moayedi
- Paul Flechsig Institute, Centre of Neuropathology and Brain Research, University of Leipzig, Leipzig, Germany
| | - Shima Zenouri
- Paul Flechsig Institute, Centre of Neuropathology and Brain Research, University of Leipzig, Leipzig, Germany
| | - Tamer Al-Maghout
- Department of Cardiology and Vascular Medicine and Physiology, University of Tübingen, Tübingen, Germany
| | - Antolin Cantó
- Departamento Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain
| | - María Miranda
- Departamento Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain
| | - Serdar Durdagi
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University, Istanbul, Turkey
- Molecular Therapy Laboratory, School of Pharmacy, Bahcesehir University, Istanbul, Turkey
| | - Zohreh Hosseinzadeh
- Paul Flechsig Institute, Centre of Neuropathology and Brain Research, University of Leipzig, Leipzig, Germany
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
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3
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Gulati S, Palczewski K. Structural view of G protein-coupled receptor signaling in the retinal rod outer segment. Trends Biochem Sci 2023; 48:172-186. [PMID: 36163145 PMCID: PMC9868064 DOI: 10.1016/j.tibs.2022.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 01/26/2023]
Abstract
Visual phototransduction is the most extensively studied G protein-coupled receptor (GPCR) signaling pathway because of its quantifiable stimulus, non-redundancy of genes, and immense importance in vision. We summarize recent discoveries that have advanced our understanding of rod outer segment (ROS) morphology and the pathological basis of retinal diseases. We have combined recently published cryo-electron tomography (cryo-ET) data on the ROS with structural knowledge on individual proteins to define the precise spatial limitations under which phototransduction occurs. Although hypothetical, the reconstruction of the rod phototransduction system highlights the potential roles of phosphodiesterase 6 (PDE6) and guanylate cyclases (GCs) in maintaining the spacing between ROS discs, suggesting a plausible mechanism by which intrinsic optical signals are generated in the retina.
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Affiliation(s)
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute and the Department of Ophthalmology, Center for Translational Vision Research, Department of Physiology and Biophysics, Department of Chemistry, Molecular Biology, and Biochemistry, University of California Irvine, 850 Health Sciences Road, Irvine, CA 92697-4375, USA.
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4
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Occelli LM, Sun K, Winkler PA, Morgan BJ, Petersen-Jones SM. Elevated retinal cGMP is not associated with elevated circulating cGMP levels in a canine model of retinitis pigmentosa. PLoS One 2022; 17:e0279437. [PMID: 36584140 PMCID: PMC9803105 DOI: 10.1371/journal.pone.0279437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/21/2022] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To investigate whether raised levels of retinal cyclic guanosine monophosphate (cGMP) was reflected in plasma levels in PDE6A-/- dogs. MATERIALS AND METHODS Retina was collected from 2-month-old wildtype dogs (PDE6A+/+, N = 6), heterozygous dogs (PDE6A+/-, N = 4) and affected dogs (PDE6A-/-, N = 3) and plasma was collected from 2-month-old wildtype dogs (PDE6A+/+, N = 5), heterozygous dogs (PDE6A+/-, N = 5) and affected dogs (PDE6A-/-, N = 5). Retina and plasma samples were measured by ELISA. RESULTS cGMP levels in retinal samples of PDE6A-/- dogs at 2 months of age were significantly elevated. There was no significant difference in plasma cGMP levels between wildtype and PDE6A-/- or PDE6A+/- puppies. However, the plasma cGMP levels of the PDE6A-/- puppies were significantly lower than that of PDE6A+/- puppies. CONCLUSION cGMP levels in the plasma from PDE6A-/- was not elevated when compared to control dogs. At the 2-month timepoint, cGMP plasma levels would not be a useful biomarker for disease.
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Affiliation(s)
- Laurence M. Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
| | - Kelian Sun
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
| | - Paige A. Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
| | - Brandy J. Morgan
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
| | - Simon M. Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail:
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5
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Preclinical Models of Retinitis Pigmentosa. Methods Mol Biol 2022; 2560:181-215. [PMID: 36481897 DOI: 10.1007/978-1-0716-2651-1_19] [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: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is the name for a group of phenotypically-related heritable retinal degenerative disorders. Many genes have been implicated as causing variants of RP, and while the clinical phenotypes are remarkably similar, they may differ in age of onset, progression, and severity. Common inheritance patterns for specific genes connected with the development of the disorder include autosomal dominant, autosomal recessive, and X-linked. Modeling the disease in animals and other preclinical systems offers a cost-conscious, ethical, and time-efficient method for studying the disease subtypes. The history of RP models is briefly examined, and both naturally occurring and transgenic preclinical models of RP in many different organisms are discussed. Syndromic forms of RP and models thereof are reviewed as well.
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6
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Kuehlewein L, Straßer T, Blumenstock G, Stingl K, Fischer MD, Wilhelm B, Zrenner E, Wissinger B, Kohl S, Weisschuh N, Zobor D. Central Visual Function and Genotype-Phenotype Correlations in PDE6A-Associated Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2022; 63:9. [PMID: 35533076 PMCID: PMC9106976 DOI: 10.1167/iovs.63.5.9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Autosomal recessive retinitis pigmentosa (arRP) can be caused by mutations in the phosphodiesterase 6A (PDE6A) gene. Here, we describe the natural course of disease progression with respect to central retinal function (i.e., visual acuity, contrast sensitivity, and color vision) and establish a detailed genotype-–phenotype correlation. Methods Forty-four patients (26 females; mean age ± SD, 43 ± 13 years) with a confirmed genetic diagnosis of PDE6A-associated arRP underwent comprehensive ophthalmological examinations including best-corrected visual acuity (BCVA) with Early Treatment Diabetic Retinopathy Study charts, contrast sensitivity (CS) with Pelli–Robson charts at distances of 3 m and 1 m, and color vision testing using Roth 28-Hue and Panel D-15 saturated color cups. Results The most frequently observed variants were c.998+1G>A/p.?, c.304C>A/p.R102S, and c.2053G>A/p.V685M. Central retinal function in patients homozygous for variant c.304C>A/p.R102S was better when compared to patients homozygous for variant c.998+1G>A/p.?, although the former were older at baseline. Central retinal function was similar in patients homozygous for variant c.304C>A/p.R102S and patients heterozygous for variants c.304C>A/p.R102S and c.2053G>A/p.V685M, although the latter were younger at baseline. Annual decline rates in central retinal function were small. Conclusions We conclude that the severity of the different disease-causing PDE6A mutations in humans with respect to central visual function may be ranked as follows: c.2053G>A/p.V685M in homozygous state (most severe) > c.998+1G>A/p.? in homozygous state > c.304C>A/p.R102S and c.2053G>A/p.V685M in compound-heterozygous state > c.304C>A/p.R102S in homozygous state (mildest). The assessment of treatment efficacy in interventional trials will remain challenging due to small annual decline rates in central retinal function.
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Affiliation(s)
- Laura Kuehlewein
- University Eye Hospital, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Torsten Straßer
- University Eye Hospital, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Gunnar Blumenstock
- Department of Clinical Epidemiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - M Dominik Fischer
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Barbara Wilhelm
- STZ eyetrial at the Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Eberhart Zrenner
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Ditta Zobor
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen, Germany.,Department of Ophthalmology, Semmelweis University, Budapest, Hungary
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7
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Lyu Y, Zauhar R, Dana N, Strang CE, Hu J, Wang K, Liu S, Pan N, Gamlin P, Kimble JA, Messinger JD, Curcio CA, Stambolian D, Li M. Implication of specific retinal cell-type involvement and gene expression changes in AMD progression using integrative analysis of single-cell and bulk RNA-seq profiling. Sci Rep 2021; 11:15612. [PMID: 34341398 PMCID: PMC8329233 DOI: 10.1038/s41598-021-95122-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
Age-related macular degeneration (AMD) is a blinding eye disease with no unifying theme for its etiology. We used single-cell RNA sequencing to analyze the transcriptomes of ~ 93,000 cells from the macula and peripheral retina from two adult human donors and bulk RNA sequencing from fifteen adult human donors with and without AMD. Analysis of our single-cell data identified 267 cell-type-specific genes. Comparison of macula and peripheral retinal regions found no cell-type differences but did identify 50 differentially expressed genes (DEGs) with about 1/3 expressed in cones. Integration of our single-cell data with bulk RNA sequencing data from normal and AMD donors showed compositional changes more pronounced in macula in rods, microglia, endothelium, Müller glia, and astrocytes in the transition from normal to advanced AMD. KEGG pathway analysis of our normal vs. advanced AMD eyes identified enrichment in complement and coagulation pathways, antigen presentation, tissue remodeling, and signaling pathways including PI3K-Akt, NOD-like, Toll-like, and Rap1. These results showcase the use of single-cell RNA sequencing to infer cell-type compositional and cell-type-specific gene expression changes in intact bulk tissue and provide a foundation for investigating molecular mechanisms of retinal disease that lead to new therapeutic targets.
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Affiliation(s)
- Yafei Lyu
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Randy Zauhar
- Department of Chemistry and Biochemistry, The University of the Sciences in Philadelphia, Philadelphia, PA, 19104, USA
| | - Nicholas Dana
- Departments of Ophthalmology and Human Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Christianne E Strang
- Department of Psychology, University of Alabama At Birmingham, Birmingham, AL, 35294, USA
| | - Jian Hu
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Kui Wang
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- Department of Information Theory and Data Science, School of Mathematical Sciences and LPMC, Nankai University, Tianjin, 30071, China
| | - Shanrun Liu
- Department of Biochemistry and Molecular Genetics, University of Alabama At Birmingham, Birmingham, AL, 35294, USA
| | - Naifei Pan
- Department of Computer and Information Science, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Paul Gamlin
- Department of Ophthalmology and Visual Sciences, University of Alabama At Birmingham, Birmingham, AL, 35294, USA
| | - James A Kimble
- Department of Ophthalmology and Visual Sciences, University of Alabama At Birmingham, Birmingham, AL, 35294, USA
| | - Jeffrey D Messinger
- Department of Ophthalmology and Visual Sciences, University of Alabama At Birmingham, Birmingham, AL, 35294, USA
| | - Christine A Curcio
- Department of Ophthalmology and Visual Sciences, University of Alabama At Birmingham, Birmingham, AL, 35294, USA
| | - Dwight Stambolian
- Departments of Ophthalmology and Human Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
| | - Mingyao Li
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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8
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Abstract
Inherited retinal diseases (IRDs) are an important cause of blindness worldwide. Over 270 genes have been associated with IRD. Genetic testing can determine the cause of the clinical disease in the majority of patients. However, at least 25-50% of patients with clinical diagnosis of IRD remain unsolved even after whole genome sequencing. Animal models of IRD can be useful for expanding the set of established IRD genes, to gain biological understanding of the function of these genes in the retina, and to test advanced therapeutics prior to human clinical trials. In this chapter some small and large animal models of IRD are discussed including some of the advantages and limitations of each for various forms of retinopathy.
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9
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Kuehlewein L, Zobor D, Andreasson SO, Ayuso C, Banfi S, Bocquet B, Bernd AS, Biskup S, Boon CJF, Downes SM, Fischer MD, Holz FG, Kellner U, Leroy BP, Meunier I, Nasser F, Rosenberg T, Rudolph G, Stingl K, Thiadens AAHJ, Wilhelm B, Wissinger B, Zrenner E, Kohl S, Weisschuh N. Clinical Phenotype and Course of PDE6A-Associated Retinitis Pigmentosa Disease, Characterized in Preparation for a Gene Supplementation Trial. JAMA Ophthalmol 2021; 138:1241-1250. [PMID: 33057649 DOI: 10.1001/jamaophthalmol.2020.4206] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Importance Treatment trials require sound knowledge on the natural course of disease. Objective To assess clinical features, genetic findings, and genotype-phenotype correlations in patients with retinitis pigmentosa (RP) associated with biallelic sequence variations in the PDE6A gene in preparation for a gene supplementation trial. Design, Setting, and Participants This prospective, longitudinal, observational cohort study was conducted from January 2001 to December 2019 in a single center (Centre for Ophthalmology of the University of Tübingen, Germany) with patients recruited multinationally from 12 collaborating European tertiary referral centers. Patients with retinitis pigmentosa, sequence variants in PDE6A, and the ability to provide informed consent were included. Exposures Comprehensive ophthalmological examinations; validation of compound heterozygosity and biallelism by familial segregation analysis, allelic cloning, or assessment of next-generation sequencing-read data, where possible. Main Outcomes and Measures Genetic findings and clinical features describing the entire cohort and comparing patients harboring the 2 most common disease-causing variants in a homozygous state (c.304C>A;p.(R102S) and c.998 + 1G>A;p.?). Results Fifty-seven patients (32 female patients [56%]; mean [SD], 40 [14] years) from 44 families were included. All patients completed the study. Thirty patients were homozygous for disease-causing alleles. Twenty-seven patients were heterozygous for 2 different PDE6A variants each. The most frequently observed alleles were c.304C>A;p.(R102S), c.998 + 1G>A;p.?, and c.2053G>A;p.(V685M). The mean (SD) best-corrected visual acuity was 0.43 (0.48) logMAR (Snellen equivalent, 20/50). The median visual field area with object III4e was 660 square degrees (5th and 95th percentiles, 76 and 11 019 square degrees; 25th and 75th percentiles, 255 and 3923 square degrees). Dark-adapted and light-adapted full-field electroretinography showed no responses in 88 of 108 eyes (81.5%). Sixty-nine of 108 eyes (62.9%) showed additional findings on optical coherence tomography imaging (eg, cystoid macular edema or macular atrophy). The variant c.998 + 1G>A;p.? led to a more severe phenotype when compared with the variant c.304C>A;p.(R102S). Conclusions and Relevance Seventeen of the PDE6A variants found in these patients appeared to be novel. Regarding the clinical findings, disease was highly symmetrical between the right and left eyes and visual impairment was mild or moderate in 90% of patients, providing a window of opportunity for gene therapy.
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Affiliation(s)
- Laura Kuehlewein
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany.,University Eye Hospital, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany
| | - Ditta Zobor
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany
| | - Sten Olof Andreasson
- Lund University, Skane University Hospital, Department of Ophthalmology, Lund, Sweden
| | - Carmen Ayuso
- Department of Genetics, IIS-Fundación Jiménez Díaz-University Hospital; Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Research on Rare Diseases, Madrid, Spain
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Pozzuoli (NA) and Medical Genetics, Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Beatrice Bocquet
- Institute for Neurosciences of Montpellier Unité 1051, University of Montpellier, Montpellier, France.,National Center for Rare Diseases, Genetics of Sensory Diseases, University Hospital, Montpellier, France
| | - Antje S Bernd
- University Eye Hospital, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany
| | | | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden University, Leiden, the Netherlands.,Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Susan M Downes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, United Kingdom
| | - M Dominik Fischer
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany.,University Eye Hospital, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany
| | - Frank G Holz
- Department of Ophthalmology, University of Bonn, Germany
| | - Ulrich Kellner
- Rare Retinal Disease Center, AugenZentrum Siegburg, MVZ Augenärztliches Diagnostik- und Therapiecentrum GmbH, Siegburg, Germany.,RetinaScience, Bonn, Germany
| | - Bart P Leroy
- Department of Ophthalmology Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Division of Ophthalmology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Center for Cellular & Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier Unité 1051, University of Montpellier, Montpellier, France.,National Center for Rare Diseases, Genetics of Sensory Diseases, University Hospital, Montpellier, France
| | - Fadi Nasser
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany
| | - Thomas Rosenberg
- Department of Ophthalmology, Kennedy Center, Rigshospitalet, Copenhagen, Denmark
| | - Günther Rudolph
- Ophthalmogenetik, Augenklinik, Klinikum der Universität München, Munich, Germany
| | - Katarina Stingl
- University Eye Hospital, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany
| | | | - Barbara Wilhelm
- STZ Eyetrial, Centre for Ophthalmology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Eberhart Zrenner
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University Tübingen, Tübingen, Germany
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10
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Crouzier L, Diez C, Richard EM, Cubedo N, Barbereau C, Rossel M, Delaunay T, Maurice T, Delprat B. Loss of Pde6a Induces Rod Outer Segment Shrinkage and Visual Alterations in pde6aQ70X Mutant Zebrafish, a Relevant Model of Retinal Dystrophy. Front Cell Dev Biol 2021; 9:675517. [PMID: 34095146 PMCID: PMC8173125 DOI: 10.3389/fcell.2021.675517] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/26/2021] [Indexed: 11/13/2022] Open
Abstract
Retinitis pigmentosa (RP) is one of the most common forms of inherited retinal degeneration with 1/4,000 people being affected. The vision alteration primarily begins with rod photoreceptor degeneration, then the degenerative process continues with cone photoreceptor death. Variants in 71 genes have been linked to RP. One of these genes, PDE6a is responsible for RP43. To date no treatment is available and patients suffer from pronounced visual impairment in early childhood. We used the novel zebrafish pde6aQ70X mutant, generated by N-ethyl-N-nitrosourea at the European Zebrafish Resource Centre, to better understand how PDE6a loss of function leads to photoreceptor alteration. Interestingly, zebrafish pde6aQ70X mutants exhibited impaired visual function at 5 dpf as evidenced by the decrease in their visual motor response (VMR) compared to pde6aWT larvae. This impaired visual function progressed with time and was more severe at 21 dpf. These modifications were associated with an alteration of rod outer segment length at 5 and 21 dpf. In summary, these findings suggest that rod outer segment shrinkage due to Pde6a deficiency begins very early in zebrafish, progresses with time. The zebrafish pde6aQ70X mutant represents an ideal model of RP to screen relevant active small molecules that will block the progression of the disease.
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Affiliation(s)
- Lucie Crouzier
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | - Camille Diez
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | | | - Nicolas Cubedo
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | | | | | | | - Tangui Maurice
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
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11
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Crane R, Conley SM, Al-Ubaidi MR, Naash MI. Gene Therapy to the Retina and the Cochlea. Front Neurosci 2021; 15:652215. [PMID: 33815052 PMCID: PMC8010260 DOI: 10.3389/fnins.2021.652215] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/22/2021] [Indexed: 12/20/2022] Open
Abstract
Vision and hearing disorders comprise the most common sensory disorders found in people. Many forms of vision and hearing loss are inherited and current treatments only provide patients with temporary or partial relief. As a result, developing genetic therapies for any of the several hundred known causative genes underlying inherited retinal and cochlear disorders has been of great interest. Recent exciting advances in gene therapy have shown promise for the clinical treatment of inherited retinal diseases, and while clinical gene therapies for cochlear disease are not yet available, research in the last several years has resulted in significant advancement in preclinical development for gene delivery to the cochlea. Furthermore, the development of somatic targeted genome editing using CRISPR/Cas9 has brought new possibilities for the treatment of dominant or gain-of-function disease. Here we discuss the current state of gene therapy for inherited diseases of the retina and cochlea with an eye toward areas that still need additional development.
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Affiliation(s)
- Ryan Crane
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
| | - Shannon M. Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Neurosciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Muayyad R. Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
- College of Optometry, University of Houston, Houston, TX, United States
- Depatment of Biology and Biochemistry, University of Houston, Houston, TX, United States
| | - Muna I. Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
- College of Optometry, University of Houston, Houston, TX, United States
- Depatment of Biology and Biochemistry, University of Houston, Houston, TX, United States
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12
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A new PDE6A missense variant p.Arg544Gln in rod-cone dystrophy. Doc Ophthalmol 2021; 143:107-114. [PMID: 33611760 DOI: 10.1007/s10633-021-09826-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 02/05/2021] [Indexed: 10/22/2022]
Abstract
PURPOSE Thus far, only one Japanese patient with autosomal recessive rod-cone dystrophy (AR-RCD) associated with the phosphodiesterase 6A gene (PDE6A) has been reported. The purpose of this study was to analyze the clinical features of a Japanese female patient with AR-RCD with a novel missense variant in PDE6A. METHODS We performed whole-exome sequencing (WES) to identify the disease-causing variant and a comprehensive ophthalmic examination including full-field electroretinography (ERG). RESULTS WES analysis revealed that the patient carried a novel homozygous missense variant (c.1631G > A; p.Arg544Gln) in PDE6A. Her unaffected parents carried the heterozygous variant. The patient reported night blindness in her early 20 s. At the age of 25 years, she underwent a comprehensive ophthalmic examination. Her corrected visual acuity was 20/13 in the right and 20/10 in the left eyes. Fundus images showed degenerative changes with bone spicule pigmentation in the mid-peripheral retina, and peripheral retinal vessels were not attenuated. Ultra-wide-field fundus autofluorescence images demonstrated large hypoautofluorescent regions corresponding to the degenerative changes, surrounded by hyperautofluorescence. Cross-sectional optical coherence tomography demonstrated a preserved ellipsoid zone and retinal thickness in the center of the macula, with perifoveal atrophy. ERG responses were subnormal, revealing that rod-mediated responses were more affected than cone-mediated responses, consistent with findings observed in RCD. CONCLUSIONS This is the second case of a patient with AR-RCD associated with PDE6A in the Japanese population. These findings will contribute to a better clinical understanding of PDE6A-associated RCD and valuable insights for gene therapy trials.
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13
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Collin GB, Gogna N, Chang B, Damkham N, Pinkney J, Hyde LF, Stone L, Naggert JK, Nishina PM, Krebs MP. Mouse Models of Inherited Retinal Degeneration with Photoreceptor Cell Loss. Cells 2020; 9:cells9040931. [PMID: 32290105 PMCID: PMC7227028 DOI: 10.3390/cells9040931] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degeneration (RD) leads to the impairment or loss of vision in millions of individuals worldwide, most frequently due to the loss of photoreceptor (PR) cells. Animal models, particularly the laboratory mouse, have been used to understand the pathogenic mechanisms that underlie PR cell loss and to explore therapies that may prevent, delay, or reverse RD. Here, we reviewed entries in the Mouse Genome Informatics and PubMed databases to compile a comprehensive list of monogenic mouse models in which PR cell loss is demonstrated. The progression of PR cell loss with postnatal age was documented in mutant alleles of genes grouped by biological function. As anticipated, a wide range in the onset and rate of cell loss was observed among the reported models. The analysis underscored relationships between RD genes and ciliary function, transcription-coupled DNA damage repair, and cellular chloride homeostasis. Comparing the mouse gene list to human RD genes identified in the RetNet database revealed that mouse models are available for 40% of the known human diseases, suggesting opportunities for future research. This work may provide insight into the molecular players and pathways through which PR degenerative disease occurs and may be useful for planning translational studies.
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Affiliation(s)
- Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Navdeep Gogna
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Nattaya Damkham
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Jai Pinkney
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lillian F. Hyde
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Jürgen K. Naggert
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
| | - Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
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14
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Retinal Organoids derived from hiPSCs of an AIPL1-LCA Patient Maintain Cytoarchitecture despite Reduced levels of Mutant AIPL1. Sci Rep 2020; 10:5426. [PMID: 32214115 PMCID: PMC7096529 DOI: 10.1038/s41598-020-62047-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 03/02/2020] [Indexed: 12/22/2022] Open
Abstract
Aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1) is a photoreceptor-specific chaperone that stabilizes the effector enzyme of phototransduction, cGMP phosphodiesterase 6 (PDE6). Mutations in the AIPL1 gene cause a severe inherited retinal dystrophy, Leber congenital amaurosis type 4 (LCA4), that manifests as the loss of vision during the first year of life. In this study, we generated three-dimensional (3D) retinal organoids (ROs) from human induced pluripotent stem cells (hiPSCs) derived from an LCA4 patient carrying a Cys89Arg mutation in AIPL1. This study aimed to (i) explore whether the patient hiPSC-derived ROs recapitulate LCA4 disease phenotype, and (ii) generate a clinically relevant resource to investigate the molecular mechanism of disease and safely test novel therapies for LCA4 in vitro. We demonstrate reduced levels of the mutant AIPL1 and PDE6 proteins in patient organoids, corroborating the findings in animal models; however, patient-derived organoids maintained retinal cell cytoarchitecture despite significantly reduced levels of AIPL1.
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15
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Khateb S, Nassisi M, Bujakowska KM, Méjécase C, Condroyer C, Antonio A, Foussard M, Démontant V, Mohand-Saïd S, Sahel JA, Zeitz C, Audo I. Longitudinal Clinical Follow-up and Genetic Spectrum of Patients With Rod-Cone Dystrophy Associated With Mutations in PDE6A and PDE6B. JAMA Ophthalmol 2020; 137:669-679. [PMID: 30998820 DOI: 10.1001/jamaophthalmol.2018.6367] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Importance A precise phenotypic characterization of retinal dystrophies is needed for disease modeling as a basis for future therapeutic interventions. Objective To compare genotype, phenotype, and structural changes in patients with rod-cone dystrophy (RCD) associated with mutations in PDE6A or PDE6B. Design, Setting, and Participants In a retrospective cohort study conducted in Paris, France, from January 2007 to September 2017, 54 patients from a cohort of 1095 index patients with RCD underwent clinical examination, including personal and familial history, best-corrected visual acuity (BCVA), color vision, slitlamp examination, full-field electroretinography, kinetic visual fields (VFs), retinophotography, optical coherence tomography, near-infrared fundus autofluorescence, and short-wavelength fundus autofluorescence imaging. Genotyping was performed using microarray analysis, targeted next-generation sequencing, and Sanger sequencing validation with familial segregation when possible. Data were analyzed from September 1, 2017, to February 1, 2018. Clinical variables were subsequently analyzed in 2018. Main Outcomes and Measures Phenotype and genotype comparison of patients carrying mutations in PDE6A or PDE6B. Results Of the 54 patients included in the study, 19 patients of 17 families (11 women [58%]; mean [SD] age at diagnosis, 14.83 [10.63] years) carried pathogenic mutations in PDE6A, and 35 patients of 26 families (17 women [49%]; mean [SD] age at diagnosis, 21.10 [11.56] years) had mutations in PDE6B, accounting for prevalences of 1.6% and 2.4%, respectively. Among 49 identified genetic variants, 14 in PDE6A and 15 in PDE6B were novel. Overall, phenotypic analysis revealed no substantial differences between the 2 groups except for night blindness as a presenting symptom that was noted to be more prevalent in the PDE6A than PDE6B group (80% vs 37%, respectively; P = .005). The mean binocular BCVA and VF decrease over time (measured as mean individual slopes coefficients) was comparable between patients with PDE6A and PDE6B mutations: 0.04 (0.12) vs 0.02 (0.05) for BCVA (P = .89) and 14.33 (7.12) vs 13.27 (6.77) for VF (P = .48). Conclusions and Relevance Mutations in PDE6A and PDE6B accounted for 1.6% and 2.4%, respectively, in a cohort of French patients with RCD. The functional and structural findings reported may constitute the basis of disease modeling that might be used for better prognostic estimation and candidate selection for photoreceptor therapeutic rescue.
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Affiliation(s)
- Samer Khateb
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France.,Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Marco Nassisi
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France
| | - Kinga M Bujakowska
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Cécile Méjécase
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Christel Condroyer
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Aline Antonio
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France
| | - Marine Foussard
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Vanessa Démontant
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Saddek Mohand-Saïd
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France
| | - José-Alain Sahel
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France.,Fondation Ophtalmologique Adolphe de Rothschild, Paris, France.,Department of Ophthalmology, The University of Pittsburgh Medical School, Pittsburgh, Pennsylvania.,Académie des Sciences-Institut de France, Paris, France
| | - Christina Zeitz
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Isabelle Audo
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France.,Institute of Ophthalmology, University College London, London, United Kingdom
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16
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Petersen-Jones SM, Occelli LM, Biel M, Michalakis S. Advancing Gene Therapy for PDE6A Retinitis Pigmentosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1185:103-107. [PMID: 31884596 DOI: 10.1007/978-3-030-27378-1_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Mutations in the gene encoding the phosphodiesterase 6 alpha subunit (PDE6A) account for 3-4% of autosomal recessive retinitis pigmentosa (RP), and currently no treatment is available. There are four animal models for PDE6A-RP: a dog with a frameshift truncating mutation (p.Asn616ThrfsTer39) and three mouse models with missense mutations (Val685Met, Asp562Trp, and Asp670Gly) showing a range of phenotype severities. Initial proof-of-concept gene augmentation studies in the Asp670Gly mouse model and dog model used a subretinally delivered adeno-associated virus serotype 8 with a 733 tyrosine capsid mutation delivering species-specific Pde6a cDNAs. These restored some rod-mediated function and preserved retinal structure. Subsequently, a translatable vector (AAV8 with a human rhodopsin promoter and human PDE6A cDNA) was tested in the dog and the Asp670Gly mouse model. In the dog, there was restoration of rod function, a robust rod-mediated ERG, and introduction of dim-light vision. Treatment improved morphology of the photoreceptor layer, and the retina was preserved in the treated region. In the Asp670Gly mouse, therapy also preserved photoreceptors with cone survival being reflected by maintenance of cone-mediated ERG responses. These studies are an important step toward a translatable therapy for PDE6A-RP.
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Affiliation(s)
- Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, Veterinary Medical Center, Michigan State University, East Lansing, MI, USA.
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, Veterinary Medical Center, Michigan State University, East Lansing, MI, USA
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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17
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Blond F, Léveillard T. Functional Genomics of the Retina to Elucidate its Construction and Deconstruction. Int J Mol Sci 2019; 20:E4922. [PMID: 31590277 PMCID: PMC6801968 DOI: 10.3390/ijms20194922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/01/2019] [Indexed: 12/20/2022] Open
Abstract
The retina is the light sensitive part of the eye and nervous tissue that have been used extensively to characterize the function of the central nervous system. The retina has a central position both in fundamental biology and in the physiopathology of neurodegenerative diseases. We address the contribution of functional genomics to the understanding of retinal biology by reviewing key events in their historical perspective as an introduction to major findings that were obtained through the study of the retina using genomics, transcriptomics and proteomics. We illustrate our purpose by showing that most of the genes of interest for retinal development and those involved in inherited retinal degenerations have a restricted expression to the retina and most particularly to photoreceptors cells. We show that the exponential growth of data generated by functional genomics is a future challenge not only in terms of storage but also in terms of accessibility to the scientific community of retinal biologists in the future. Finally, we emphasize on novel perspectives that emerge from the development of redox-proteomics, the new frontier in retinal biology.
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Affiliation(s)
- Frédéric Blond
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
| | - Thierry Léveillard
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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18
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Power M, Das S, Schütze K, Marigo V, Ekström P, Paquet-Durand F. Cellular mechanisms of hereditary photoreceptor degeneration - Focus on cGMP. Prog Retin Eye Res 2019; 74:100772. [PMID: 31374251 DOI: 10.1016/j.preteyeres.2019.07.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022]
Abstract
The cellular mechanisms underlying hereditary photoreceptor degeneration are still poorly understood, a problem that is exacerbated by the enormous genetic heterogeneity of this disease group. However, the last decade has yielded a wealth of new knowledge on degenerative pathways and their diversity. Notably, a central role of cGMP-signalling has surfaced for photoreceptor cell death triggered by a subset of disease-causing mutations. In this review, we examine key aspects relevant for photoreceptor degeneration of hereditary origin. The topics covered include energy metabolism, epigenetics, protein quality control, as well as cGMP- and Ca2+-signalling, and how the related molecular and metabolic processes may trigger photoreceptor demise. We compare and integrate evidence on different cell death mechanisms that have been associated with photoreceptor degeneration, including apoptosis, necrosis, necroptosis, and PARthanatos. A special focus is then put on the mechanisms of cGMP-dependent cell death and how exceedingly high photoreceptor cGMP levels may cause activation of Ca2+-dependent calpain-type proteases, histone deacetylases and poly-ADP-ribose polymerase. An evaluation of the available literature reveals that a large group of patients suffering from hereditary photoreceptor degeneration carry mutations that are likely to trigger cGMP-dependent cell death, making this pathway a prime target for future therapy development. Finally, an outlook is given into technological and methodological developments that will with time likely contribute to a comprehensive overview over the entire metabolic complexity of photoreceptor cell death. Building on such developments, new imaging technology and novel biomarkers may be used to develop clinical test strategies, that fully consider the genetic heterogeneity of hereditary retinal degenerations, in order to facilitate clinical testing of novel treatment approaches.
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Affiliation(s)
- Michael Power
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Centre for Integrative Neurosciences (CIN), University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | - Soumyaparna Das
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | | | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Sweden
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany.
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19
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Sakamoto K, Mori A, Ishii K, Nakahara T. [Selective neuronal cell death in retinal degenerative diseases]. Nihon Yakurigaku Zasshi 2018; 152:58-63. [PMID: 30101861 DOI: 10.1254/fpj.152.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Retinal degenerative diseases, such as glaucoma and retinitis pigmentosa (RP), are the leading causes of blindness in adults. In Japan, glaucoma is a leading cause, and RP is third major cause of acquired blindness. Specific types of neurons are injured in the patients of glaucoma and RP. Retinal ganglion cells (RGC) are specifically degenerated in glaucoma. Excitotoxicity caused by excess glutamate in the retinal extracellular space is thought to be one of the mechanisms of RGC death induced by glaucoma and retinal central artery occlusion. Retinal ischemia-reperfusion, intravitreal NMDA injection, intravitreal NO donor injection and knock out of glutamate aspartate transporter, which are used as the experimental models of glaucoma, are known to induce RGC death. RGCs are vulnerable for excess glutamate and oxidative stress related to NO, and this vulnerability may be involved in pathogenesis of glaucomatous optic neuropathy. RP, which is characterized by progressive photoreceptor-selective degeneration, is caused by mutation of the genes related to the function of photoreceptor and retinal pigment epithelium. It has not been thoroughly clarified how the mutations induce specific photoreceptor death. Tunicamycin is widely known to induce ER stress, and intravitreal tunicamycin cause photoreceptor-specific degeneration. Therefore, ER stress may cause photoreceptor-selective degeneration in RP.
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Affiliation(s)
- Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Kunio Ishii
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences.,Pharmaceutical Education Center, Yokohama University of Pharmacy
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
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20
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Takahashi VKL, Takiuti JT, Jauregui R, Tsang SH. Gene therapy in inherited retinal degenerative diseases, a review. Ophthalmic Genet 2018; 39:560-568. [PMID: 30040511 DOI: 10.1080/13816810.2018.1495745] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hereditary diseases of the retina represent a group of diseases with several heterogeneous mutations that have the common end result of progressive photoreceptor death leading to blindness. Retinal degenerations encompass multifactorial diseases such as age-related macular degeneration, Leber congenital amaurosis, Stargardt disease, and retinitis pigmentosa. Although there is currently no cure for degenerative retinal diseases, ophthalmology has been at the forefront of the development of gene therapy, which offers hope for the treatment of these conditions. This article will explore an overview of the clinical trials of gene supplementation therapy for retinal diseases that are underway or planned for the near future.
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Affiliation(s)
- Vitor K L Takahashi
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,c Department of Ophthalmology , Federal University of São Paulo , São Paulo , Brazil
| | - Júlia T Takiuti
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,d Division of Ophthalmology , University of São Paulo Medical School , São Paulo , Brazil
| | - Ruben Jauregui
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,e Weill Cornell Medical College , New York , NY , USA
| | - Stephen H Tsang
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,f Department of Pathology & Cell Biology, Stem Cell Initiative (CSCI), Institute of Human Nutrition, College of Physicians and Surgeons , Columbia University , New York , NY , USA
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21
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Petit L, Ma S, Cheng SY, Gao G, Punzo C. Rod Outer Segment Development Influences AAV-Mediated Photoreceptor Transduction After Subretinal Injection. Hum Gene Ther 2018; 28:464-481. [PMID: 28510482 PMCID: PMC5488363 DOI: 10.1089/hum.2017.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Vectors based on the adeno-associated virus (AAV) are currently the preferred tools for delivering genes to photoreceptors (PR) in small and large animals. AAVs have been applied successfully in various models of PR dystrophies. However, unknown barriers still limit AAV's efficient application in several forms of severe PR degenerations due to insufficient transgene expression and/or treated cells at the time of injection. Optimizations of PR gene therapy strategies will likely benefit from the identification of the cellular factors that influence PR transduction. Interestingly, recent studies have shown that the AAV transduction profile of PRs differs significantly between neonatal and adult mouse retinas after subretinal injection. This phenomenon may provide clues to identify host factors that influence the efficiency of AAV-mediated PR transduction. This study demonstrates that rod outer segments are critical modulators of efficient AAV-mediated rod transduction. During retinal development, rod transduction correlated temporally and spatially with the differentiation order of PRs when vectors were introduced subretinally but not when introduced intravitreally. All subretinally injected vectors had an initial preference to transduce cones in the absence of formed rod outer segments and then displayed a preference for rods as the cells matured, independently of the expression cassette or AAV serotype. Consistent with this observation, altered development of rod outer segments was associated with a strong reduction of rod transduction and an increase in the percentage of transduced cones by 2- to 2.8-fold. A similar increase of cone transduction was observed in the adult retinal degeneration 1 (rd1) retina compared to wild-type mice. These results suggest that the loss of rod outer segments in diseased retinas could markedly affect gene transfer efficiency of AAV vectors by limiting the ability of AAVs to infect dying rods efficiently. This information could be exploited for the development of more efficient AAV-based PR gene delivery procedures.
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Affiliation(s)
- Lolita Petit
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Shan Ma
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Shun-Yun Cheng
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Guangping Gao
- 3 Department of Microbiology and Physiological Systems and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Claudio Punzo
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts.,2 Department of Neurobiology, University of Massachusetts Medical School , Worcester, Massachusetts
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22
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Combination of cGMP analogue and drug delivery system provides functional protection in hereditary retinal degeneration. Proc Natl Acad Sci U S A 2018. [PMID: 29531030 PMCID: PMC5879685 DOI: 10.1073/pnas.1718792115] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Development of treatments for hereditary degeneration of the retina (RD) is hampered by the vast genetic heterogeneity of this group of diseases and by the delivery of the drug to an organ protected by the blood–retina barrier. Here, we present an approach for the treatment of different types of RD, combining an innovative drug therapy with a liposomal system that facilitates drug delivery into the retina. Using different animal models of RD we show that this pharmacological treatment preserved both the viability of cells in the retina as well as retinal function. Thus, our study provides an avenue for the development of therapies for hereditary diseases which cause blindness, an unmet medical need. Inherited retinal degeneration (RD) is a devastating and currently untreatable neurodegenerative condition that leads to loss of photoreceptor cells and blindness. The vast genetic heterogeneity of RD, the lack of “druggable” targets, and the access-limiting blood–retinal barrier (BRB) present major hurdles toward effective therapy development. Here, we address these challenges (i) by targeting cGMP (cyclic guanosine- 3′,5′-monophosphate) signaling, a disease driver common to different types of RD, and (ii) by combining inhibitory cGMP analogs with a nanosized liposomal drug delivery system designed to facilitate transport across the BRB. Based on a screen of several cGMP analogs we identified an inhibitory cGMP analog that interferes with activation of photoreceptor cell death pathways. Moreover, we found liposomal encapsulation of the analog to achieve efficient drug targeting to the neuroretina. This pharmacological treatment markedly preserved in vivo retinal function and counteracted photoreceptor degeneration in three different in vivo RD models. Taken together, we show that a defined class of compounds for RD treatment in combination with an innovative drug delivery method may enable a single type of treatment to address genetically divergent RD-type diseases.
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23
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Abstract
Genetic mouse models mimicking human diseases have been developed and utilized for retinal research in various topics, involving anatomy, physiology, biochemistry, and pathology. The main reasons why mouse models are important for retinal research include that rodents share a key retinal homology with humans and that genetic manipulation is relatively easily applicable for mice. Here, we describe genetic mouse models, which are categorized with functions in the retina and relationship with human diseases.
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Affiliation(s)
- Akiko Maeda
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Tadao Maeda
- Research Division, Kobe Research Institute, HEALIOS K.K., Kobe, Japan.
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24
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Schön C, Sothilingam V, Mühlfriedel R, Garcia Garrido M, Beck SC, Tanimoto N, Wissinger B, Paquet-Durand F, Biel M, Michalakis S, Seeliger MW. Gene Therapy Successfully Delays Degeneration in a Mouse Model of PDE6A-Linked Retinitis Pigmentosa (RP43). Hum Gene Ther 2017; 28:1180-1188. [PMID: 29212391 DOI: 10.1089/hum.2017.156] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Retinitis pigmentosa type 43 (RP43) is a blinding disease caused by mutations in the gene for rod phosphodiesterase 6 alpha (PDE6A). The disease process begins with a dysfunction of rod photoreceptors, subsequently followed by a currently untreatable progressive degeneration of the entire outer retina. Aiming at a curative approach via PDE6A gene supplementation, a novel adeno-associated viral (AAV) vector was developed for expression of the human PDE6A cDNA under control of the human rhodopsin promotor (rAAV8.PDE6A). This study assessed the therapeutic efficacy of rAAV8.PDE6A in the Pde6anmf363/nmf363-mutant mouse model of RP43. All mice included in this study were treated with sub-retinal injections of the vector at 2 weeks after birth. The therapeutic effect was monitored at 1 month and 6 months post injection. Biological function of the transgene was assessed in vivo by means of electroretinography. The degree of morphological rescue was investigated both in vivo using optical coherence tomography and ex vivo by immunohistological staining. It was found that the novel rAAV8.PDE6A vector resulted in a stable and efficient expression of PDE6A protein in rod photoreceptors of Pde6anmf363/nmf363 mice following treatment at both the short- and long-term time points. The treatment led to a substantial morphological preservation of outer nuclear layer thickness, rod outer segment structure, and prolonged survival of cone photoreceptors for at least 6 months. Additionally, the ERG analysis confirmed a restoration of retinal function in a group of treated mice. Taken together, this study provides successful proof-of-concept for the cross-species efficacy of the rAAV8.PDE6A vector developed for use in human patients. Importantly, the data show stable expression and rescue effects for a prolonged period of time, raising hope for future translational studies based on this approach.
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Affiliation(s)
- Christian Schön
- Center for Integrated Protein Science Munich CiPSM at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Regine Mühlfriedel
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Marina Garcia Garrido
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Susanne C Beck
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Naoyuki Tanimoto
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Eberhard Karls University, Tuebingen, Germany
| | - François Paquet-Durand
- Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University, Tuebingen, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPSM at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich CiPSM at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mathias W Seeliger
- Divisions of Ocular Neurodegeneration, Eberhard Karls University, Tuebingen, Germany
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25
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Occelli LM, Schön C, Seeliger MW, Biel M, Michalakis S, Petersen-Jones SM. Gene Supplementation Rescues Rod Function and Preserves Photoreceptor and Retinal Morphology in Dogs, Leading the Way Toward Treating Human PDE6A-Retinitis Pigmentosa. Hum Gene Ther 2017; 28:1189-1201. [PMID: 29212382 DOI: 10.1089/hum.2017.155] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutations in the phosphodiesterase 6A gene (PDE6A) result in retinitis pigmentosa (RP) type 43 (RP43) and are responsible for about 4% of autosomal recessive RP. There is currently no treatment for this blinding condition. The aim of this project was to use a large-animal model to test a gene supplementation viral vector designed to be translated for use in a clinical trial for the treatment of RP43. Seven Pde6a-/- puppies were given sub-retinal injections of an adeno-associated viral vector (AAV) serotype 2/8 delivering human PDE6A cDNA under control of a short rhodopsin promoter (AAV8-PDE6A). Three puppies received ∼1 × 1011 vg in one eye and four puppies ∼5 × 1011 vg/per eye, with both eyes being injected in two animals. In vivo outcome measures included vision testing and electroretinography (ERG), as well as fundus and spectral domain-optical coherence tomography imaging. Some puppies were euthanized and their eyes processed for immunohistochemistry. All puppies had improved rod-mediated vision in the treated eye. ERGs showed improved rod-mediated responses in the higher-dose group but in only one of the lower-dose group animals. Receptor+ thickness was preserved and photoreceptor morphology improved in the treated retinal regions in all puppies. Treatment resulted in PDE6A transgene expression, accompanied by much increased levels of Pde6b, in rod outer segments in the injected retinal regions. There were several indications of improved retinal health in the PDE6A-expressing regions, including lack of abnormal cyclic guanosine monophosphate accumulation, appropriate rod opsin localization to the outer segments with a large reduction in mislocalization to other regions of the rod cell, and reduced Müller cell activation. Additionally, cone photoreceptors showed morphological improvement in the treated region, with normal-appearing inner and outer segments. AAV8-PDE6A gene supplementation therapy restored rod vision in Pde6a-/- puppies and preserved retinal morphology. These positive outcomes are an important step toward a human clinical trial to treat PDE6A-RP.
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Affiliation(s)
- Laurence M Occelli
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan
| | - Christian Schön
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University, Tuebingen, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan
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26
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Mowat FM, Occelli LM, Bartoe JT, Gervais KJ, Bruewer AR, Querubin J, Dinculescu A, Boye SL, Hauswirth WW, Petersen-Jones SM. Gene Therapy in a Large Animal Model of PDE6A-Retinitis Pigmentosa. Front Neurosci 2017; 11:342. [PMID: 28676737 PMCID: PMC5476745 DOI: 10.3389/fnins.2017.00342] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/01/2017] [Indexed: 12/13/2022] Open
Abstract
Despite mutations in the rod phosphodiesterase 6-alpha (PDE6A) gene being well-recognized as a cause of human retinitis pigmentosa, no definitive treatments have been developed to treat this blinding disease. We performed a trial of retinal gene augmentation in the Pde6a mutant dog using Pde6a delivery by capsid-mutant adeno-associated virus serotype 8, previously shown to have a rapid onset of transgene expression in the canine retina. Subretinal injections were performed in 10 dogs at 29–44 days of age, and electroretinography and vision testing were performed to assess functional outcome. Retinal structure was assessed using color fundus photography, spectral domain optical coherence tomography, and histology. Immunohistochemistry was performed to examine transgene expression and expression of other retinal genes. Treatment resulted in improvement in dim light vision and evidence of rod function on electroretinographic examination. Photoreceptor layer thickness in the treated area was preserved compared with the contralateral control vector treated or uninjected eye. Improved rod and cone photoreceptor survival, rhodopsin localization, cyclic GMP levels and bipolar cell dendrite distribution was observed in treated areas. Some adverse effects including foci of retinal separation, foci of retinal degeneration and rosette formation were identified in both AAV-Pde6a and control vector injected regions. This is the first description of successful gene augmentation for Pde6a retinitis pigmentosa in a large animal model. Further studies will be necessary to optimize visual outcomes and minimize complications before translation to human studies.
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Affiliation(s)
- Freya M Mowat
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State UniversityRaleigh, NC, United States
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Joshua T Bartoe
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Kristen J Gervais
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Ashlee R Bruewer
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Janice Querubin
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Astra Dinculescu
- Department of Ophthalmology, University of Florida College of MedicineGainesville, FL, United States
| | - Sanford L Boye
- Department of Ophthalmology, University of Florida College of MedicineGainesville, FL, United States
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida College of MedicineGainesville, FL, United States
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
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27
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Butler MR, Ma H, Yang F, Belcher J, Le YZ, Mikoshiba K, Biel M, Michalakis S, Iuso A, Križaj D, Ding XQ. Endoplasmic reticulum (ER) Ca 2+-channel activity contributes to ER stress and cone death in cyclic nucleotide-gated channel deficiency. J Biol Chem 2017; 292:11189-11205. [PMID: 28495882 DOI: 10.1074/jbc.m117.782326] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/01/2017] [Indexed: 02/05/2023] Open
Abstract
Endoplasmic reticulum (ER) stress and mislocalization of improperly folded proteins have been shown to contribute to photoreceptor death in models of inherited retinal degenerative diseases. In particular, mice with cone cyclic nucleotide-gated (CNG) channel deficiency, a model for achromatopsia, display both early-onset ER stress and opsin mistrafficking. By 2 weeks of age, these mice show elevated signaling from all three arms of the ER-stress pathway, and by 1 month, cone opsin is improperly distributed away from its normal outer segment location to other retinal layers. This work investigated the role of Ca2+-release channels in ER stress, protein mislocalization, and cone death in a mouse model of CNG-channel deficiency. We examined whether preservation of luminal Ca2+ stores through pharmacological and genetic suppression of ER Ca2+ efflux protects cones by attenuating ER stress. We demonstrated that the inhibition of ER Ca2+-efflux channels reduced all three arms of ER-stress signaling while improving opsin trafficking to cone outer segments and decreasing cone death by 20-35%. Cone-specific gene deletion of the inositol-1,4,5-trisphosphate receptor type I (IP3R1) also significantly increased cone density in the CNG-channel-deficient mice, suggesting that IP3R1 signaling contributes to Ca2+ homeostasis and cone survival. Consistent with the important contribution of organellar Ca2+ signaling in this achromatopsia mouse model, significant differences in dynamic intraorganellar Ca2+ levels were detected in CNG-channel-deficient cones. These results thus identify a novel molecular link between Ca2+ homeostasis and cone degeneration, thereby revealing novel therapeutic targets to preserve cones in inherited retinal degenerative diseases.
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Affiliation(s)
| | | | - Fan Yang
- From the Departments of Cell Biology
| | | | - Yun-Zheng Le
- From the Departments of Cell Biology.,Internal Medicine, and.,Ophthalmology and.,the Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Katsuhiko Mikoshiba
- the Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Hirosawa Wako-shi, Saitama 351-0198, Japan
| | - Martin Biel
- the Center for Integrated Protein Science Munich (CIPSM) and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany, and
| | - Stylianos Michalakis
- the Center for Integrated Protein Science Munich (CIPSM) and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany, and
| | - Anthony Iuso
- the John A. Moran Eye Center, University of Utah, Salt Lake City, Utah 84132
| | - David Križaj
- the John A. Moran Eye Center, University of Utah, Salt Lake City, Utah 84132
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28
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Taking Stock of Retinal Gene Therapy: Looking Back and Moving Forward. Mol Ther 2017; 25:1076-1094. [PMID: 28391961 DOI: 10.1016/j.ymthe.2017.03.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/04/2017] [Accepted: 03/04/2017] [Indexed: 11/23/2022] Open
Abstract
Over the past 20 years, there has been tremendous progress in retinal gene therapy. The safety and efficacy results in one early-onset severe blinding disease may lead to the first gene therapy drug approval in the United States. Here, we review how far the field has come over the past two decades and speculate on the directions that the field will take in the future.
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29
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Jiao K, Sahaboglu A, Zrenner E, Ueffing M, Ekström PAR, Paquet-Durand F. Efficacy of PARP inhibition in Pde6a mutant mouse models for retinitis pigmentosa depends on the quality and composition of individual human mutations. Cell Death Discov 2016; 2:16040. [PMID: 27551530 PMCID: PMC4979439 DOI: 10.1038/cddiscovery.2016.40] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 04/28/2016] [Indexed: 11/09/2022] Open
Abstract
Retinitis pigmentosa (RP), an inherited blinding disease, is caused by a variety of different mutations that affect retinal photoreceptor function and survival. So far there is neither effective treatment nor cure. We have previously shown that poly(ADP-ribose)polymerase (PARP) acts as a common and critical denominator of cell death in photoreceptors, qualifying it as a potential target for future therapeutic intervention. A significant fraction of RP-causing mutations affect the genes for the rod photoreceptor phosphodiesterase 6A (PDE6A) subunit, but it is not known whether they all engage the same death pathway. Analysing three homozygous point mutations (Pde6a R562W, D670G, and V685M) and one compound heterozygous Pde6aV685M/R562W mutation in mouse models that match human RP patients, we demonstrate excessive activation of PARP, which correlated in time with the progression of photoreceptor degeneration. The causal involvement of PARP activity in the neurodegenerative process was confirmed in organotypic retinal explant cultures treated with the PARP-selective inhibitor PJ34, using different treatment time-points and durations. Remarkably, the neuroprotective efficacy of PARP inhibition correlated inversely with the strength of the genetically induced insult, with the D670G mutant showing the best treatment effects. Our results highlight PARP as a target for neuroprotective interventions in RP caused by PDE6A mutations and are a first attempt towards personalized, genotype-matched therapy development for RP. In addition, for each of the different mutant situations, our work identifies windows of opportunity for an optimal treatment regimen for further in vivo experimentation and possibly clinical studies.
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Affiliation(s)
- K Jiao
- Cell Death Mechanisms Group, Division of Experimental Ophthalmology, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany; Centre for Ophthalmology, The Second People's Hospital of Yunnan Province and The Fourth Affiliated Hospital of Kunming Medical University, Qingnian 176, Kunming 650021, China
| | - A Sahaboglu
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tuebingen , Tuebingen 72076, Germany
| | - E Zrenner
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tuebingen, Tuebingen 72076, Germany; Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tuebingen, Tuebingen, Germany
| | - M Ueffing
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tuebingen , Tuebingen 72076, Germany
| | - P A R Ekström
- Division of Ophthalmology, Department of Clinical Sciences, Lund, University of Lund , Lund 22184, Sweden
| | - F Paquet-Durand
- Cell Death Mechanisms Group, Division of Experimental Ophthalmology, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tuebingen , Roentgenweg 11, Tuebingen 72076, Germany
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30
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Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity. Nat Genet 2015; 48:144-51. [PMID: 26691986 PMCID: PMC4787620 DOI: 10.1038/ng.3474] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 11/25/2015] [Indexed: 11/11/2022]
Abstract
Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here, we report the identification of heterozygous missense mutations in the α-catenin 1 (CTNNA1) gene in three families with butterfly-shaped pigment dystrophy. In addition, we identified a Ctnna1 missense mutation in a chemically induced mouse mutant, tvrm5. Parallel clinical phenotypes were observed in the retinal pigment epithelium (RPE) of individuals with butterfly-shaped pigment dystrophy and in tvrm5 mice, including pigmentary abnormalities, focal thickening and elevated lesions, and decreased light-activated responses. Morphological studies in tvrm5 mice revealed increased cell shedding and large multinucleated RPE cells, suggesting defects in intercellular adhesion and cytokinesis. This study identifies CTNNA1 gene variants as a cause of macular dystrophy, suggests that CTNNA1 is involved in maintaining RPE integrity, and suggests that other components that participate in intercellular adhesion may be implicated in macular disease.
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31
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Furukawa A, Koriyama Y. A role of Heat Shock Protein 70 in Photoreceptor Cell Death: Potential as a Novel Therapeutic Target in Retinal Degeneration. CNS Neurosci Ther 2015; 22:7-14. [PMID: 26507240 DOI: 10.1111/cns.12471] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 01/17/2023] Open
Abstract
Retinal degenerative diseases (RDs) such as retinitis pigmentosa (RP) are a genetically heterogeneous group of disorders characterized by night blindness and peripheral vision loss, which caused by the dysfunction and death of photoreceptor cells. Although many causative gene mutations have been reported, the final common end stage is photoreceptor cell death. Unfortunately, no effective treatments or therapeutic agents have been discovered. Heat shock protein 70 (HSP70) is highly conserved and has antiapoptotic activities. A few reports have shown that HSP70 plays a role in RDs. Thus, we focused on the role of HSP70 in photoreceptor cell death. Using the N-methyl-N-nitrosourea (MNU)-induced photoreceptor cell death model in mice, we could examine two stages of the novel cell death mechanism; the early stage, including HSP70 cleavage through protein carbonylation by production of reactive oxygen species, lipid peroxidation and Ca(2+) influx/calpain activation, and the late stage of cathepsin and/or caspase activation. The upregulation of intact HSP70 expression by its inducer is likely to protect photoreceptor cells. In this review, we focus on the role of HSP70 and the novel cell death signaling process in RDs. We also describe candidate therapeutic agents for RDs.
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Affiliation(s)
- Ayako Furukawa
- Graduate School and Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan
| | - Yoshiki Koriyama
- Graduate School and Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan
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32
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Veleri S, Lazar CH, Chang B, Sieving PA, Banin E, Swaroop A. Biology and therapy of inherited retinal degenerative disease: insights from mouse models. Dis Model Mech 2015; 8:109-29. [PMID: 25650393 PMCID: PMC4314777 DOI: 10.1242/dmm.017913] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases.
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Affiliation(s)
- Shobi Veleri
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Csilla H Lazar
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano Sciences, Babes-Bolyai-University, Cluj-Napoca, 400271, Romania
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eyal Banin
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Center for Retinal and Macular Degenerations, Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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33
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The pros and cons of vertebrate animal models for functional and therapeutic research on inherited retinal dystrophies. Prog Retin Eye Res 2015; 48:137-59. [DOI: 10.1016/j.preteyeres.2015.04.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/12/2015] [Accepted: 04/16/2015] [Indexed: 01/19/2023]
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Sothilingam V, Garcia Garrido M, Jiao K, Buena-Atienza E, Sahaboglu A, Trifunović D, Balendran S, Koepfli T, Mühlfriedel R, Schön C, Biel M, Heckmann A, Beck SC, Michalakis S, Wissinger B, Seeliger MW, Paquet-Durand F. Retinitis pigmentosa: impact of different Pde6a point mutations on the disease phenotype. Hum Mol Genet 2015; 24:5486-99. [PMID: 26188004 DOI: 10.1093/hmg/ddv275] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/09/2015] [Indexed: 11/13/2022] Open
Abstract
Mutations in the PDE6A gene can cause rod photoreceptors degeneration and the blinding disease retinitis pigmentosa (RP). While a number of pathogenic PDE6A mutations have been described, little is known about their impact on compound heterozygous situations and potential interactions of different disease-causing alleles. Here, we used a novel mouse model for the Pde6a R562W mutation in combination with an existing line carrying the V685M mutation to generate compound heterozygous Pde6a V685M/R562W animals, exactly homologous to a case of human RP. We compared the progression of photoreceptor degeneration in these compound heterozygous mice with the homozygous V685M and R562W mutants, and additionally with the D670G line that is known for a relatively mild phenotype. We investigated PDE6A expression, cyclic guanosine mono-phosphate accumulation, calpain and caspase activity, in vivo retinal function and morphology, as well as photoreceptor cell death and survival. This analysis confirms the severity of different Pde6a mutations and indicates that compound heterozygous mutants behave like intermediates of the respective homozygous situations. Specifically, the severity of the four different Pde6a situations may be categorized by the pace of photoreceptor degeneration: V685M (fastest) > V685M/R562W > R562W > D670G (slowest). While calpain activity was strongly increased in all four mutants, caspase activity was not. This points to the execution of non-apoptotic cell death and may lead to the identification of new targets for therapeutic interventions. For individual RP patients, our study may help to predict time-courses for Pde6a-related retinal degeneration and thereby facilitate the definition of a window-of-opportunity for clinical interventions.
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Affiliation(s)
- Vithiyanjali Sothilingam
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Schleichstr.4/3, Tuebingen 72076, Germany
| | - Marina Garcia Garrido
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Schleichstr.4/3, Tuebingen 72076, Germany
| | - Kangwei Jiao
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany, Second People's Hospital of Yunnan Province and Fourth Affiliated Hospital of Kunming Medical University, 176 Qingnian Road, Wuhua, Kunming, Yunnan 650021, China
| | - Elena Buena-Atienza
- Molecular Genetics Laboratory, Centre for Ophthalmology, University Clinics Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany
| | - Ayse Sahaboglu
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany
| | - Dragana Trifunović
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany
| | - Sukirthini Balendran
- Molecular Genetics Laboratory, Centre for Ophthalmology, University Clinics Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany
| | - Tanja Koepfli
- Molecular Genetics Laboratory, Centre for Ophthalmology, University Clinics Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany
| | - Regine Mühlfriedel
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Schleichstr.4/3, Tuebingen 72076, Germany
| | - Christian Schön
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich 81377, Germany and
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich 81377, Germany and
| | | | - Susanne C Beck
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Schleichstr.4/3, Tuebingen 72076, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich 81377, Germany and
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Centre for Ophthalmology, University Clinics Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Schleichstr.4/3, Tuebingen 72076, Germany
| | - François Paquet-Durand
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Roentgenweg 11, Tuebingen 72076, Germany,
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Abstract
Despite remarkable progress in the identification of mutations that drive genetic disorders, progress in understanding the effect of genetic background on the penetrance and expressivity of causal alleles has been modest, in part because of the methodological challenges in identifying genetic modifiers. Nonetheless, the progressive discovery of modifier alleles has improved both our interpretative ability and our analytical tools to dissect such phenomena. In this review, we analyze the genetic properties and behaviors of modifiers as derived from studies in patient populations and model organisms and we highlight conceptual and technological tools used to overcome some of the challenges inherent in modifier mapping and cloning. Finally, we discuss how the identification of these modifiers has facilitated the elucidation of biological pathways and holds the potential to improve the clinical predictive value of primary causal mutations and to develop novel drug targets.
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Affiliation(s)
- Maria Kousi
- Center for Human Disease Modeling, Duke University, Durham, North Carolina 27710
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University, Durham, North Carolina 27710
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Sakamoto K, Mori A, Nakahara T, Morita M, Ishii K. Effect of Long-Term Treatment of L-Ornithine on Visual Function and Retinal Histology in the Rats. Biol Pharm Bull 2015; 38:139-43. [DOI: 10.1248/bpb.b14-00491] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Masahiko Morita
- Healthcare Products Development Center, Kyowa Hakko Bio Co., Ltd
| | - Kunio Ishii
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
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Azevedo MF, Faucz FR, Bimpaki E, Horvath A, Levy I, de Alexandre RB, Ahmad F, Manganiello V, Stratakis CA. Clinical and molecular genetics of the phosphodiesterases (PDEs). Endocr Rev 2014; 35:195-233. [PMID: 24311737 PMCID: PMC3963262 DOI: 10.1210/er.2013-1053] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 11/06/2013] [Indexed: 12/31/2022]
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) are enzymes that have the unique function of terminating cyclic nucleotide signaling by catalyzing the hydrolysis of cAMP and GMP. They are critical regulators of the intracellular concentrations of cAMP and cGMP as well as of their signaling pathways and downstream biological effects. PDEs have been exploited pharmacologically for more than half a century, and some of the most successful drugs worldwide today affect PDE function. Recently, mutations in PDE genes have been identified as causative of certain human genetic diseases; even more recently, functional variants of PDE genes have been suggested to play a potential role in predisposition to tumors and/or cancer, especially in cAMP-sensitive tissues. Mouse models have been developed that point to wide developmental effects of PDEs from heart function to reproduction, to tumors, and beyond. This review brings together knowledge from a variety of disciplines (biochemistry and pharmacology, oncology, endocrinology, and reproductive sciences) with emphasis on recent research on PDEs, how PDEs affect cAMP and cGMP signaling in health and disease, and what pharmacological exploitations of PDEs may be useful in modulating cyclic nucleotide signaling in a way that prevents or treats certain human diseases.
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Affiliation(s)
- Monalisa F Azevedo
- Section on Endocrinology Genetics (M.F.A., F.R.F., E.B., A.H., I.L., R.B.d.A., C.A.S.), Program on Developmental Endocrinology Genetics, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland 20892; Section of Endocrinology (M.F.A.), University Hospital of Brasilia, Faculty of Medicine, University of Brasilia, Brasilia 70840-901, Brazil; Group for Advanced Molecular Investigation (F.R.F., R.B.d.A.), Graduate Program in Health Science, Medical School, Pontificia Universidade Catolica do Paraná, Curitiba 80215-901, Brazil; Cardiovascular Pulmonary Branch (F.A., V.M.), National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland 20892; and Pediatric Endocrinology Inter-Institute Training Program (C.A.S.), NICHD, NIH, Bethesda, Maryland 20892
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Wert KJ, Sancho-Pelluz J, Tsang SH. Mid-stage intervention achieves similar efficacy as conventional early-stage treatment using gene therapy in a pre-clinical model of retinitis pigmentosa. Hum Mol Genet 2013; 23:514-23. [PMID: 24101599 DOI: 10.1093/hmg/ddt452] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Deficiencies in rod-specific cyclic guanosine monophosphate (cGMP) phosphodiesterase-6 (PDE6) are the third most common cause of autosomal recessive retinitis pigmentosa (RP). Previously, viral gene therapy approaches on pre-clinical models with mutations in PDE6 have demonstrated that the photoreceptor cell survival and visual function can be rescued when the gene therapy virus is delivered into the subretinal space before the onset of disease. However, no studies have currently been published that analyze rescue effects after disease onset, a time when human RP patients are diagnosed by a clinician and would receive the treatment. We utilized the AAV2/8(Y733F)-Rho-Pde6α gene therapy virus and injected it into a pre-clinical model of RP with a mutation within the alpha subunit of PDE6: Pde6α(D670G). These mice were previously shown to have long-term photoreceptor cell rescue when this gene therapy virus was delivered before the onset of disease. Now, we have determined that subretinal transduction of this rod-specific transgene at post-natal day (P) 21, when approximately half of the photoreceptor cells have undergone degeneration, is more efficient in rescuing cone than rod photoreceptor function long term. Therefore, AAV2/8(Y733F)-Rho-Pde6α is an effective gene therapy treatment that can be utilized in the clinical setting, in human patients who have lost portions of their peripheral visual field and are in the mid-stage of disease when they first present to an eye-care professional.
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Affiliation(s)
- Katherine J Wert
- Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology
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39
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Chang B, Hurd R, Wang J, Nishina P. Survey of common eye diseases in laboratory mouse strains. Invest Ophthalmol Vis Sci 2013; 54:4974-81. [PMID: 23800770 DOI: 10.1167/iovs.13-12289] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE As in human populations, in which founder mutations have been identified in groups of families, a number of founder mutations have been observed across strains in mice. In this report, we provide a phenotype and genotype survey of three common eye diseases in the collection of JAX mice strains at The Jackson Laboratory (JAX). These eye diseases are retinal degeneration 1 (Pde6b(rd1)), retinal degeneration 8 (Crb1(rd8)), and cone photoreceptor function loss 3 (Gnat2(cpfl3)). METHODS Ocular lesions for rd1 and rd8 were evaluated by fundus examination and fundus photography, and the abnormal retinal function observed in mice homozygous for cpfl3 was assessed by ERG. Genotyping protocols for rd1, rd8, and cpfl3 mutations were performed by PCR with appropriate primers. RESULTS We have actively screened retired breeders for surface dysmorphologies, and for intraocular defects by indirect ophthalmoscopy, slit-lamp biomicroscopy, and ERG to discover new spontaneous mutations in strains from the Genetic Resource Science (GRS) production colony. Through this process, we have found that of the strains screened, 99 strains carried the rd1 mutation, 85 strains carried the rd8 mutation, and 20 strains carried the cpfl3 mutation. CONCLUSIONS Of the 1000 of strains screened during this study, 204 carried one of three founder mutations in Pde6b, Crb1, or Gnat2. Since these three retinal mutations occur commonly in various mouse strains, genotyping for these mutations, and/or avoiding mouse strains or stocks carrying these mutant alleles when studying new retinal disorders is recommended. The robust PCR genotyping protocols to test for these common alleles are described herein.
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Affiliation(s)
- Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine 04609, USA.
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40
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Martínez-Fernández de la Cámara C, Sequedo MD, Gómez-Pinedo U, Jaijo T, Aller E, García-Tárraga P, García-Verdugo JM, Millán JM, Rodrigo R. Phosphodiesterase inhibition induces retinal degeneration, oxidative stress and inflammation in cone-enriched cultures of porcine retina. Exp Eye Res 2013; 111:122-33. [PMID: 23578797 DOI: 10.1016/j.exer.2013.03.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 03/15/2013] [Accepted: 03/19/2013] [Indexed: 10/27/2022]
Abstract
Inherited retinal degenerations affecting both rod and cone photoreceptors constitute one of the causes of incurable blindness in the developed world. Cyclic guanosine monophosphate (cGMP) is crucial in the phototransduction and, mutations in genes related to its metabolism are responsible for different retinal dystrophies. cGMP-degrading phosphodiesterase 6 (PDE6) mutations cause around 4-5% of the retinitis pigmentosa, a rare form of retinal degeneration. The aim of this study was to evaluate whether pharmacological PDE6 inhibition induced retinal degeneration in cone-enriched cultures of porcine retina similar to that found in murine models. PDE6 inhibition was induced in cone-enriched retinal explants from pigs by Zaprinast. PDE6 inhibition induced cGMP accumulation and triggered retinal degeneration, as determined by TUNEL assay. Western blot analysis and immunostaining indicated that degeneration was accompanied by caspase-3, calpain-2 activation and poly (ADP-ribose) accumulation. Oxidative stress markers, total antioxidant capacity, thiobarbituric acid reactive substances (TBARS) and nitric oxide measurements revealed the presence of oxidative damage. Elevated TNF-alpha and IL-6, as determined by enzyme immunoassay, were also found in cone-enriched retinal explants treated with Zaprinast. Our study suggests that this ex vivo model of retinal degeneration in porcine retina could be an alternative model for therapeutic research into the mechanisms of photoreceptor death in cone-related diseases, thus replacing or reducing animal experiments.
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41
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A novel mouse Dscam mutation inhibits localization and shedding of DSCAM. PLoS One 2012; 7:e52652. [PMID: 23300735 PMCID: PMC3530462 DOI: 10.1371/journal.pone.0052652] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 11/19/2012] [Indexed: 11/25/2022] Open
Abstract
The differential adhesion hypothesis of development states that patterning of organisms, organs and tissues is mediated in large part by expression of cell adhesion molecules. The cues provided by cell adhesion molecules are also hypothesized to facilitate specific connectivity within the nervous system. In this study we characterize a novel mouse mutation in the gene Dscam (Down Syndrome Cell Adhesion Molecule). Vertebrate DSCAM is required for normal development of the central nervous system and has been best characterized in the visual system. In the visual system DSCAM is required for regulation of cell number, mosaic formation, laminar specificity, and refinement of retinal-tectal projections. We have identified a novel mutation in Dscam that results in a single amino acid substitution, R1018P, in the extracellular domain of the DSCAM protein. Mice homozygous for the R1018P mutation develop a subset of defects observed in Dscam null mice. In vitro analysis identified defects in DSCAMR1018P localization to filopodia. We also find that wild type DSCAM protein is constitutively cleaved and shed from transfected cells. This secretion is inhibited by the R1018P mutation. We also characterized a novel splice isoform of Dscam and identified defects in lamination of type 2 and type 6 cone bipolar cells in Dscam mutant mice. The identification and characterization of partial loss of function mutations in genes such as Dscam will be helpful in predicting signs and symptoms that may be observed in human patients with partial loss of DSCAM function.
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42
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Wert KJ, Davis RJ, Sancho-Pelluz J, Nishina PM, Tsang SH. Gene therapy provides long-term visual function in a pre-clinical model of retinitis pigmentosa. Hum Mol Genet 2012; 22:558-67. [PMID: 23108158 DOI: 10.1093/hmg/dds466] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Approximately 36 000 cases of simplex and familial retinitis pigmentosa (RP) worldwide are caused by a loss in phosphodiesterase (PDE6) function. In the preclinical Pde6α(nmf363) mouse model of this disease, defects in the α-subunit of PDE6 result in a progressive loss of photoreceptors and neuronal function. We hypothesized that increasing PDE6α levels using an AAV2/8 gene therapy vector could improve photoreceptor survival and retinal function. We utilized a vector with the cell-type-specific rhodopsin (RHO) promoter: AAV2/8(Y733F)-Rho-Pde6α, to transduce Pde6α(nmf363) retinas and monitored its effects over a 6-month period (a quarter of the mouse lifespan). We found that a single injection enhanced survival of photoreceptors and improved retinal function. At 6 months of age, the treated eyes retained photoreceptor cell bodies, while there were no detectable photoreceptors remaining in the untreated eyes. More importantly, the treated eyes demonstrated functional visual responses even after the untreated eyes had lost all vision. Despite focal rescue of the retinal structure adjacent to the injection site, global functional rescue of the entire retina was observed. These results suggest that RP due to PDE6α deficiency in humans, in addition to PDE6β deficiency, is also likely to be treatable by gene therapy.
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Affiliation(s)
- Katherine J Wert
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Columbia University, New York, NY 10032, USA
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43
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Atypical retinal degeneration 3 in mice is caused by defective PDE6B pre-mRNA splicing. Vision Res 2012; 57:1-8. [PMID: 22326271 DOI: 10.1016/j.visres.2012.01.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/20/2012] [Accepted: 01/26/2012] [Indexed: 01/23/2023]
Abstract
Mutations in the key rod phototransduction enzyme phosphodiesterase 6 (PDE6) are known to cause recessive retinitis pigmentosa in humans. Mouse models of mutant PDE6 represent a common approach to understanding the mechanisms of visual disorders related to PDE6 defects. Mutation N605S in the PDE6B subunit is linked to atypical retinal degeneration 3 (atrd3) in mice. We examined PDE6 in atrd3 mice and an atrd3 mutant counterpart of human cone PDE6C expressed in rods of transgenic Xenopus laevis. These animal models revealed remarkably different phenotypes. In contrast to dramatic downregulation of the mutant rod PDE6 protein and activity levels in mice, expression and localization of the cone PDE6C in X. laevis were essentially unaffected by this mutation. Examination of the PDE6B mRNA in atrd3 retina showed that the mutation-carrying exon 14 was spliced-out in the majority of the transcript. Thus, retinal degeneration in atrd3 mice is caused by low levels of PDE6 protein due to defective processing of PDE6B pre-mRNA rather than by deleterious effects of the N605S mutation on PDE6 folding, stability or function.
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44
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Won J, Shi LY, Hicks W, Wang J, Naggert JK, Nishina PM. Translational vision research models program. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 723:391-7. [PMID: 22183357 DOI: 10.1007/978-1-4614-0631-0_50] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
ENU mutagenesis is an efficient method to identify new animal models of ocular disease. The new alleles described herein will be a useful resource to further examine the role of the affected molecules and the effects of their disruption within the retina.
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Affiliation(s)
- Jungyeon Won
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
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45
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Kolandaivelu S, Chang B, Ramamurthy V. Rod phosphodiesterase-6 (PDE6) catalytic subunits restore cone function in a mouse model lacking cone PDE6 catalytic subunit. J Biol Chem 2011; 286:33252-9. [PMID: 21799013 DOI: 10.1074/jbc.m111.259101] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Rod and cone photoreceptor neurons utilize discrete PDE6 enzymes that are crucial for phototransduction. Rod PDE6 is composed of heterodimeric catalytic subunits (αβ), while the catalytic core of cone PDE6 (α') is a homodimer. It is not known if variations between PDE6 subunits preclude rod PDE6 catalytic subunits from coupling to the cone phototransduction pathway. To study this issue, we generated a cone-dominated mouse model lacking cone PDE6 (Nrl(-/-) cpfl1). In this animal model, using several independent experimental approaches, we demonstrated the expression of rod PDE6 (αβ) and the absence of cone PDE6 (α') catalytic subunits. The rod PDE6 enzyme expressed in cone cells is active and contributes to the hydrolysis of cGMP in response to light. In addition, rod PDE6 expressed in cone cells couples to the light signaling pathway to produce S-cone responses. However, S-cone responses and light-dependent cGMP hydrolysis were eliminated when the β-subunit of rod PDE6 was removed (Nrl(-/-) cpfl1 rd). We conclude that either rod or cone PDE6 can effectively couple to the cone phototransduction pathway to mediate visual signaling. Interestingly, we also found that functional PDE6 is required for trafficking of M-opsin to cone outer segments.
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Affiliation(s)
- Saravanan Kolandaivelu
- Departments of Ophthalmology and Biochemistry, Center for Neuroscience, West Virginia University, Morgantown, West Virginia 26506, USA
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46
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Peiró AM, Tang CM, Murray F, Zhang L, Brown LM, Chou D, Rassenti L, Kipps TJ, Kipps TA, Insel PA. Genetic variation in phosphodiesterase (PDE) 7B in chronic lymphocytic leukemia: overview of genetic variants of cyclic nucleotide PDEs in human disease. J Hum Genet 2011; 56:676-81. [PMID: 21796143 DOI: 10.1038/jhg.2011.80] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Expression of cyclic adenosine monophosphate-specific phosphodiesterase 7B (PDE7B) mRNA is increased in patients with chronic lymphocytic leukemia (CLL), thus suggesting that variation may occur in the PDE7B gene in CLL. As genetic variation in other PDE family members has been shown to associate with numerous clinical disorders (reviewed in this manuscript), we sought to identify single-nucleotide polymorphisms (SNPs) in the PDE7B gene promoter and coding region of 93 control subjects and 154 CLL patients. We found that the PDE7B gene has a 5' non-coding region SNP -347C>T that occurs with similar frequency in CLL patients (1.9%) and controls (2.7%). Tested in vitro, -347C>T has less promoter activity than a wild-type construct. The low frequency of this 5' untranslated region variant indicates that it does not explain the higher PDE7B expression in patients with CLL but it has the potential to influence other settings that involve a role for PDE7B.
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Affiliation(s)
- Ana M Peiró
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093-0636, USA
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47
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Fuerst PG, Harris BS, Johnson KR, Burgess RW. A novel null allele of mouse DSCAM survives to adulthood on an inbred C3H background with reduced phenotypic variability. Genesis 2011; 48:578-84. [PMID: 20715164 DOI: 10.1002/dvg.20662] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
DSCAMs are cell adhesion molecules that play several important roles in neurodevelopment. Mouse alleles of Dscam identified to date do not survive on an inbred C57BL/6 background, complicating analysis of DSCAM-dependent developmental processes because of phenotypic variability related to the segregating backgrounds needed for postnatal survival. A novel spontaneous allele of Dscam, hereafter referred to as Dscam²(J), has been identified. This allele contains a four base pair duplication in exon 19, leading to a frameshift and truncation of the open reading frame. Mice homozygous for the Dscam²(J) mutant allele survive into adulthood on the C3H/HeJ background on which the mutation was identified. Using the Dscam²(J) allele, retinal phenotypes that have variable severity on a segregating background were examined. A neurite lamination defect similar to that described in chick was discovered in mice. These results indicate that, in the retina, additional DSCAM-dependent processes can be found by analysis of mutations on different genetic backgrounds.
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48
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Fletcher EL, Jobling AI, Vessey KA, Luu C, Guymer RH, Baird PN. Animal models of retinal disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 100:211-86. [PMID: 21377628 DOI: 10.1016/b978-0-12-384878-9.00006-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Diseases of the retina are the leading causes of blindness in the industrialized world. The recognition that animals develop retinal diseases with similar traits to humans has led to not only a dramatic improvement in our understanding of the pathogenesis of retinal disease but also provided a means for testing possible treatment regimes and successful gene therapy trials. With the advent of genetic and molecular biological tools, the association between specific gene mutations and retinal signs has been made. Animals carrying natural mutations usually in one gene now provide well-established models for a host of inherited retinal diseases, including retinitis pigmentosa, Leber congenital amaurosis, inherited macular degeneration, and optic nerve diseases. In addition, the development of transgenic technologies has provided a means by which to study the effects of these and novel induced mutations on retinal structure and function. Despite these advances, there is a paucity of suitable animal models for complex diseases, including age-related macular degeneration (AMD) and diabetic retinopathy, largely because these diseases are not caused by single gene defects, but involve complex genetics and/or exacerbation through environmental factors, epigenetic, or other modes of genetic influence. In this review, we outline in detail the available animal models for inherited retinal diseases and how this information has furthered our understanding of retinal diseases. We also examine how transgenic technologies have helped to develop our understanding of the role of isolated genes or pathways in complex diseases like AMD, diabetes, and glaucoma.
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Affiliation(s)
- Erica L Fletcher
- Department of Anatomy and Cell Biology, The University of Melbourne, Parkville, Victoria, Australia
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49
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Sakamoto K, Mori A, Nakahara T, Ishii K. [Cause of retinitis pigmentosa and new therapeutics under development]. Nihon Yakurigaku Zasshi 2011; 137:22-26. [PMID: 21233585 DOI: 10.1254/fpj.137.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Won J, Marín de Evsikova C, Smith RS, Hicks WL, Edwards MM, Longo-Guess C, Li T, Naggert JK, Nishina PM. NPHP4 is necessary for normal photoreceptor ribbon synapse maintenance and outer segment formation, and for sperm development. Hum Mol Genet 2010; 20:482-96. [PMID: 21078623 DOI: 10.1093/hmg/ddq494] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Nephronophthisis (NPHP) is an autosomal recessive kidney disease that is often associated with vision and/or brain defects. To date, 11 genes are known to cause NPHP. The gene products, while structurally unrelated, all localize to cilia or centrosomes. Although mouse models of NPHP are available for 9 of the 11 genes, none has been described for nephronophthisis 4 (Nphp4). Here we report a novel, chemically induced mutant, nmf192, that bears a nonsense mutation in exon 4 of Nphp4. Homozygous mutant Nphp4(nmf192/nmf192) mice do not exhibit renal defects, phenotypes observed in human patients bearing mutations in NPHP4, but they do develop severe photoreceptor degeneration and extinguished rod and cone ERG responses by 9 weeks of age. Photoreceptor outer segments (OS) fail to develop properly, and some OS markers mislocalize to the inner segments and outer nuclear layer in the Nphp4(nmf192/nmf192) mutant retina. Despite NPHP4 localization to the transition zone in the connecting cilia (CC), the CC appear to be normal in structure and ciliary transport function is partially retained. Likewise, synaptic ribbons develop normally but then rapidly degenerate by P14. Finally, Nphp4(nmf192/nmf192) male mutants are sterile and show reduced sperm motility and epididymal sperm counts. Although Nphp4(nmf192/nmf192) mice fail to recapitulate the kidney phenotype of NPHP, they will provide a valuable tool to further elucidate how NPHP4 functions in the retina and male reproductive organs.
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Affiliation(s)
- Jungyeon Won
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
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