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Hashem SA, Georgiou M, Wright G, Fujinami-Yokokawa Y, Laich Y, Varela MD, de Guimaraes TAC, Mahroo OA, Webster AR, Fujinami K, Michaelides M. PDE6A-Associated Retinitis Pigmentosa, Clinical Characteristics, Genetics and Natural History. Ophthalmol Retina 2024:S2468-6530(24)00405-6. [PMID: 39218074 DOI: 10.1016/j.oret.2024.08.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 08/09/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024]
Abstract
PURPOSE To analyze the genetics, clinical characteristics, and natural history of PDE6A-associated retinitis pigmentosa. DESIGN Retrospective, longitudinal, observational cohort study. PARTICIPANTS Patients with molecularly confirmed PDE6A-associated retinal dystrophy in a single tertiary referral center. METHODS Review of medical records and retinal imaging, including fundus autofluorescence (FAF) imaging and spectral-domain optical coherence tomography (SD-OCT). Genetic results were reviewed, and the detected variants were assessed. RESULTS Sixteen patients (32 eyes) were identified and evaluated longitudinally. Genetic analysis identified 14 variants in the PDE6A gene, including 8 novel variants. The mean age (±SD, range) was 34.8 years (± 17.4, 12 - 76) at baseline, with a mean follow-up time of 4.8 years. Best-corrected visual acuity (BCVA) was 0.45 ± 0.45 LogMAR (range 0.0 - 1.6) at baseline and 0.65 ± 0.7 LogMAR (range 0.0 - 2.3) at the last visit. BCVA was similar among eyes in 88% of patients. A hyperautofluorescent ring was observed on FAF in 50% and 44% of the eyes at baseline and follow up visit respectively, with a mean area of 9.7 ± 4.5mm2 at baseline and mean of 8.6 ± 4.8 mm2 at the follow-up visit. Mean horizontal ellipsoid zone width (EZW) at baseline was 1765 ± 1093 μm, which decreased to 1580 ± 1077 μm at follow up. Eighteen eyes exhibited cystoid macular oedema at baseline (56%), and 17 eyes (53%) at follow-up. There were statistically significant changes during the follow-up period in terms of BCVA, hyperautoflouroscent ring area and the EZW. CONCLUSIONS This study highlights the natural history of PDE6A-retinopathy. The majority of the patients in this cohort had mild BCVA loss, and slowly progressive disease, based on FAF and OCT measurements.
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Affiliation(s)
- Shaima Awadh Hashem
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
| | - Genevieve Wright
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Yannik Laich
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Eye Center, Faculty of Medicine, University Freiburg, Germany.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Thales A C de Guimaraes
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King's College London, London, UK; Department of Twin Research and Genetic Epidemiology, King's College London; Eye Department, St Thomas' Hospital, London, UK; Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo, Japan.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Rajala A, Rajala R, Bhat MA, Eminhizer M, Hao J, Du J, Rajala RVS. Age-related retinal degeneration resulting from the deletion of Shp2 tyrosine phosphatase in photoreceptor neurons. Cell Death Dis 2024; 15:577. [PMID: 39117618 PMCID: PMC11310310 DOI: 10.1038/s41419-024-06924-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 06/28/2024] [Accepted: 07/18/2024] [Indexed: 08/10/2024]
Abstract
Shp2, a critical SH2-domain-containing tyrosine phosphatase, is essential for cellular regulation and implicated in metabolic disruptions, obesity, diabetes, Noonan syndrome, LEOPARD syndrome, and cancers. This study focuses on Shp2 in rod photoreceptor cells, revealing its enrichment, particularly in rods. Deletion of Shp2 in rods leads to age-dependent photoreceptor degeneration. Shp2 targets occludin (OCLN), a tight junction protein, and its deletion reduces OCLN expression in the retina and retinal pigment epithelium (RPE). The isolation of actively translating mRNAs from rods lacking Shp2, followed by RNA sequencing, reveals alterations in cell cycle regulation. Additionally, altered retinal metabolism is observed in retinal cells lacking Shp2. Our studies indicate that Shp2 is crucial for maintaining the structure and function of photoreceptors.
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Affiliation(s)
- Ammaji Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Dean McGee Eye Institute, Oklahoma City, OK, 73104, USA
| | - Rahul Rajala
- Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Mohd A Bhat
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Dean McGee Eye Institute, Oklahoma City, OK, 73104, USA
| | - Mark Eminhizer
- Departments of Ophthalmology and Visual Sciences and Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV, 26505, USA
| | - Jeff Hao
- Departments of Ophthalmology and Visual Sciences and Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV, 26505, USA
| | - Jianhai Du
- Departments of Ophthalmology and Visual Sciences and Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV, 26505, USA
| | - Raju V S Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
- Dean McGee Eye Institute, Oklahoma City, OK, 73104, USA.
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
- Department of Biochemistry and Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
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Liu Y, Zong X, Cao W, Zhang W, Zhang N, Yang N. Gene Therapy for Retinitis Pigmentosa: Current Challenges and New Progress. Biomolecules 2024; 14:903. [PMID: 39199291 PMCID: PMC11352491 DOI: 10.3390/biom14080903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/14/2024] [Accepted: 07/23/2024] [Indexed: 09/01/2024] Open
Abstract
Retinitis pigmentosa (RP) poses a significant threat to eye health worldwide, with prevalence rates of 1 in 5000 worldwide. This genetically diverse retinopathy is characterized by the loss of photoreceptor cells and atrophy of the retinal pigment epithelium. Despite the involvement of more than 3000 mutations across approximately 90 genes in its onset, finding an effective treatment has been challenging for a considerable time. However, advancements in scientific research, especially in gene therapy, are significantly expanding treatment options for this most prevalent inherited eye disease, with the discovery of new compounds, gene-editing techniques, and gene loci offering hope for more effective treatments. Gene therapy, a promising technology, utilizes viral or non-viral vectors to correct genetic defects by either replacing or silencing disease-causing genes, potentially leading to complete recovery. In this review, we primarily focus on the latest applications of gene editing research in RP. We delve into the most prevalent genes associated with RP and discuss advancements in genome-editing strategies currently employed to correct various disease-causing mutations.
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Affiliation(s)
| | | | | | | | - Ningzhi Zhang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China; (Y.L.); (X.Z.); (W.C.); (W.Z.)
| | - Ning Yang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China; (Y.L.); (X.Z.); (W.C.); (W.Z.)
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Jentzsch MC, Tsang SH, Koch SF. A New Preclinical Model of Retinitis Pigmentosa Due to Pde6g Deficiency. OPHTHALMOLOGY SCIENCE 2023; 3:100332. [PMID: 37363133 PMCID: PMC10285708 DOI: 10.1016/j.xops.2023.100332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 06/28/2023]
Abstract
Purpose Retinitis pigmentosa (RP) is the most common cause of inherited blindness, with onset occurring as early as 4 years of age in certain rare but severe forms caused by mutations in the gamma subunit of phosphodiesterase 6 (PDE6). Studies in humans and mice have shown that RP pathology begins with progressive photoreceptor death, which then drives changes in downstream neurons, neighboring retinal pigment epithelium (RPE), and vasculature. Here, we present the first detailed analysis of RP disease progression in Pde6g-deficient mice. Design Experimental study of an RP mouse model. Subjects We studied Pde6g-/- and Pde6g+/- mice at the age of 7, 16, 30, 44, and 56 days with n = 2 to 5 per group and time point. Methods Photoreceptor degeneration and retinal remodeling were analyzed in retinal sections by immunofluorescence. Retinal blood vessel degradation was analyzed in flat-mounted retinas immunolabeled for isolectin GS-IB4. Protein expression was measured by immunoblot. Acellular capillaries were assessed in trypsin-digested and hematoxylin-eosin-stained retinas at postnatal day (P) 44. Retinal pigment epithelium cells were delineated in flat-mounted RPE-choroid-sclera by immunolabeling for the cell-adhesion protein β-catenin. Main Outcome Measures Immunofluorescence and morphometry (quantitative analysis of outer nuclear layer, dendrite area, vessel area, acellular vessels, RPE cell size, number of nuclei per RPE cell, RPE cell eccentricity, and RPE cell solidity). Results This novel RP model exhibits early onset and rapid rod degeneration, with the vast majority gone by P16. This pathology leads to retinal remodeling, including changes of inner retinal neurons, early activation of glia cells, degradation of retinal vasculature, and structural abnormalities of the RPE. Conclusions The pathology in our Pde6g-/- mouse model precisely mirrors human RP progression. The results demonstrate the significant role of the gamma subunit in maintaining phosphodiesterase activity and provide new insights into the disease progression due to Pde6g deficiency. Financial Disclosures Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Michelle Carmen Jentzsch
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stephen H. Tsang
- Jonas Children’s Vision Care, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York
| | - Susanne Friederike Koch
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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Siles L, Gaudó P, Pomares E. High-Efficiency CRISPR/Cas9-Mediated Correction of a Homozygous Mutation in Achromatopsia-Patient-Derived iPSCs. Int J Mol Sci 2023; 24:ijms24043655. [PMID: 36835061 PMCID: PMC9964936 DOI: 10.3390/ijms24043655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/03/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
Achromatopsia is an autosomal recessive disorder, in which cone photoreceptors undergo progressive degeneration, causing color blindness and poor visual acuity, among other significant eye affectations. It belongs to a group of inherited retinal dystrophies that currently have no treatment. Although functional improvements have been reported in several ongoing gene therapy studies, more efforts and research should be carried out to enhance their clinical application. In recent years, genome editing has arisen as one of the most promising tools for personalized medicine. In this study, we aimed to correct a homozygous PDE6C pathogenic variant in hiPSCs derived from a patient affected by achromatopsia through CRISPR/Cas9 and TALENs technologies. Here, we demonstrate high efficiency in gene editing by CRISPR/Cas9 but not with TALENs approximation. Despite a few of the edited clones displaying heterozygous on-target defects, the proportion of corrected clones with a potentially restored wild-type PDE6C protein was more than half of the total clones analyzed. In addition, none of them presented off-target aberrations. These results significantly contribute to advances in single-nucleotide gene editing and the development of future strategies for the treatment of achromatopsia.
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Affiliation(s)
- Laura Siles
- Fundació de Recerca de l’Institut de Microcirurgia Ocular, 08035 Barcelona, Spain
- Departament de Genètica, IMO Grupo Miranza, 08035 Barcelona, Spain
| | - Paula Gaudó
- Fundació de Recerca de l’Institut de Microcirurgia Ocular, 08035 Barcelona, Spain
- Departament de Genètica, IMO Grupo Miranza, 08035 Barcelona, Spain
| | - Esther Pomares
- Fundació de Recerca de l’Institut de Microcirurgia Ocular, 08035 Barcelona, Spain
- Departament de Genètica, IMO Grupo Miranza, 08035 Barcelona, Spain
- Correspondence:
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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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Jaffal L, Ibrahim M, El Shamieh S. Analysis of rod-cone dystrophy genes reveals unique mutational patterns. BMJ OPEN SCIENCE 2022; 6:e100291. [PMID: 36618607 PMCID: PMC9812813 DOI: 10.1136/bmjos-2022-100291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Background Rod-cone dystrophy (RCD) is the most common inherited retinal disease that is characterised by the progressive degeneration of retinal photoreceptors. RCD genes classification is based exclusively on gene mutations' prevalence and does not consider the implication of the same gene in different phenotypes. Therefore, we first investigated the mutations occurrence in autosomal recessive RCD (arRCD) and non-arRCD conditions. Then, finally, we identified arRCD enriched mutational patterns in specific genes and coding exons. Methods and results The mutations patterns differed according to arRCD (p=0.001). Specifically, When compared with missense; insertions/deletions (OR=1.2, p=0.007), nonsense (OR=1.2, p=0.014) and splice-site mutations (OR=1.6, p=0.038) increased the OR of arRCD by 20%-60% versus non-arRCD conditions. The gene-based analysis identified that EYS, IMPG2, RP1L1 and USH2A mutations were enriched in arRCD (p<0.05). The exon-based analysis revealed specific mutation patterns in exons of CRB1, RP1L1 and exons 12, 60 and 62 coding for Lamin EGF and FTIII domains of USH2A. Conclusion The current analysis showed that many aRCD genes have unique mutational patterns.
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Affiliation(s)
- Lama Jaffal
- Department of Biological and Chemical Sciences, School of Arts and Sciences, Lebanese International University, Nabatyeh, Lebanon,Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatyeh, Lebanon
| | - Mariam Ibrahim
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatyeh, Lebanon
| | - Said El Shamieh
- Department of Medical Laboratory Technology, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
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Inhibition of the MAPK/c-Jun-EGR1 Pathway Decreases Photoreceptor Cell Death in the rd1 Mouse Model for Inherited Retinal Degeneration. Int J Mol Sci 2022; 23:ijms232314600. [PMID: 36498926 PMCID: PMC9740268 DOI: 10.3390/ijms232314600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/17/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies that typically results in photoreceptor cell death and vision loss. Here, we explored the effect of early growth response-1 (EGR1) expression on photoreceptor cell death in Pde6brd1 (rd1) mice and its mechanism of action. To this end, single-cell RNA-seq (scRNA-seq) was used to identify differentially expressed genes in rd1 and congenic wild-type (WT) mice. Chromatin immunoprecipitation (ChIP), the dual-luciferase reporter gene assay, and western blotting were used to verify the relationship between EGR1 and poly (ADP-ribose) polymerase-1 (PARP1). Immunofluorescence staining was used to assess PARP1 expression after silencing or overexpression of EGR1. Photoreceptor cell death was assessed using the TUNEL assay following silencing/overexpression of EGR1 or administration of MAPK/c-Jun pathway inhibitors tanzisertib and PD98059. Our results showed differential expression of ERG1 in rd1 and WT mice via scRNA-seq analysis. The ChIP assay demonstrated EGR1 binding to the PARP1 promoter region. The dual-luciferase reporter gene assay and western blotting results revealed that EGR1 upregulated PARP1 expression. Additionally, the TUNEL assay showed that silencing EGR1 effectively reduced photoreceptor cell death. Similarly, the addition of tanzisertib and PD98059 reduced the expression of c-Jun and EGR1 and decreased photoreceptor cell death. Our study revealed that inhibition of the MAPK/c-Jun pathway reduced the expression of EGR1 and PARP1 and prevented photoreceptor cell death. These results highlight the importance of EGR1 for photoreceptor cell death and identify a new avenue for therapeutic interventions in RP.
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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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Calpains as mechanistic drivers and therapeutic targets for ocular disease. Trends Mol Med 2022; 28:644-661. [PMID: 35641420 PMCID: PMC9345745 DOI: 10.1016/j.molmed.2022.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/03/2022] [Accepted: 05/09/2022] [Indexed: 11/18/2022]
Abstract
Ophthalmic neurodegenerative diseases encompass a wide array of molecular pathologies unified by calpain dysregulation. Calpains are calcium-dependent proteases that perpetuate cellular death and inflammation when hyperactivated. Calpain inhibition trials in other organs have faced pharmacological challenges, but the eye offers many advantages for the development and testing of targeted molecular therapeutics, including small molecules, peptides, engineered proteins, drug implants, and gene-based therapies. This review highlights structural mechanisms underlying calpain activation, distinct cellular expression patterns, and in vivo models that link calpain hyperactivity to human retinal and developmental disease. Optimizing therapeutic approaches for calpain-mediated eye diseases can help accelerate clinically feasible strategies for treating calpain dysregulation in other diseased tissues.
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11
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Xu W, Li Y, Dong Y, Xiao L, Li L, Jiao K. Integrative RNA-seq and ATAC-seq analyses of phosphodiesterase 6 mutation-induced retinitis pigmentosa. Int Ophthalmol 2022; 42:2385-2395. [PMID: 35147831 DOI: 10.1007/s10792-022-02238-0] [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: 07/20/2021] [Accepted: 01/13/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE Inhibition of poly-ADP-ribose polymerase 1 (PARP1) could relieve phosphodiesterase 6 mutation-induced retinitis pigmentosa (RP). However, the mechanism related to PARP1 overexpression in the RP has not been clarified. We attempted to explore the potential mechanism related to PARP1 regulating RP. METHODS ATAC-seq and RNA-seq were performed for retina tissues of C3H and rd1 mice. The differentially expressed genes (DEGs) were identified, followed by the construction of PARP1-DEG co-expression and protein-protein interaction (PPI) networks. Gene ontology-biological process and pathway enrichment of DEGs were performed by clusterProfiler software. The overlapped genes that might play regulatory roles in PARP1 expression were mined by integrated analysis of RNA-seq and ATAC-seq data. RESULTS A total of 1061 DEGs were identified between C3H and rd1 group. Co-expression network was constructed with 313 PARP1-gene co-expression pairs. The down-regulated DEGs were closely related to visual perception and light stimulus-related biological process, while the up-regulated DEGs were significantly enriched in phototransduction and PPAR signaling pathway. PPI network was constructed with 202 nodes and 375 edges, which was clustered into 3 modules. Module 1 genes were closely related to detection of light stimulus, visual perception related biological process and phototransduction pathway (involved with Gnat1/Guca1b/Gnat2/Sag/Pde6g). By integrated analysis of the RNA-seq and ATAC-seq, the overlapped up-regulated genes were Asxl3 and Nyap2, while the down-regulated genes were Tmem136 and Susd3. CONCLUSION Gnat1 may play a key role in RP development by interacting with PARP1. Susd3 may play a regulatory role in PARP1 expression and affect RP formation.
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Affiliation(s)
- Wenrong Xu
- Kunming Medical University, Kunming, 650500, Yunnan, China
- Department of Ophthalmology, The Affiliated Calmette Hospital of Kunming Medical University, 650024, Kunming, Yunnan, China
| | - Yan Li
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Yujie Dong
- Kunming Medical University, Kunming, 650500, Yunnan, China
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Libo Xiao
- Kunming Medical University, Kunming, 650500, Yunnan, China
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Lan Li
- Kunming Medical University, Kunming, 650500, Yunnan, China.
- Department of Ophthalmology, The Affiliated Calmette Hospital of Kunming Medical University, 650024, Kunming, Yunnan, China.
| | - Kangwei Jiao
- Kunming Medical University, Kunming, 650500, Yunnan, China.
- Department of Ophthalmology, Affiliated Hospital of Yunnan University, Yunnan University, 650021, Kunming, China.
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Yunnan University, 176 Qingnian, Kunming, 650021, China.
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12
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Das S, Popp V, Power M, Groeneveld K, Yan J, Melle C, Rogerson L, Achury M, Schwede F, Strasser T, Euler T, Paquet-Durand F, Nache V. Redefining the role of Ca 2+-permeable channels in photoreceptor degeneration using diltiazem. Cell Death Dis 2022; 13:47. [PMID: 35013127 PMCID: PMC8748460 DOI: 10.1038/s41419-021-04482-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 10/07/2021] [Accepted: 11/23/2021] [Indexed: 12/18/2022]
Abstract
Hereditary degeneration of photoreceptors has been linked to over-activation of Ca2+-permeable channels, excessive Ca2+-influx, and downstream activation of Ca2+-dependent calpain-type proteases. Unfortunately, after more than 20 years of pertinent research, unequivocal evidence proving significant and reproducible photoreceptor protection with Ca2+-channel blockers is still lacking. Here, we show that both D- and L-cis enantiomers of the anti-hypertensive drug diltiazem were very effective at blocking photoreceptor Ca2+-influx, most probably by blocking the pore of Ca2+-permeable channels. Yet, unexpectedly, this block neither reduced the activity of calpain-type proteases, nor did it result in photoreceptor protection. Remarkably, application of the L-cis enantiomer of diltiazem even led to a strong increase in photoreceptor cell death. These findings shed doubt on the previously proposed links between Ca2+ and retinal degeneration and are highly relevant for future therapy development as they may serve to refocus research efforts towards alternative, Ca2+-independent degenerative mechanisms.
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Affiliation(s)
- Soumyaparna Das
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Valerie Popp
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Michael Power
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076, Tübingen, Germany
| | - Kathrin Groeneveld
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany.,Biomolecular Photonics Group, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Jie Yan
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Christian Melle
- Biomolecular Photonics Group, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Luke Rogerson
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076, Tübingen, Germany
| | - Marlly Achury
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Frank Schwede
- BIOLOG Life Science Institute GmbH & Co KG, 28199, Bremen, Germany
| | - Torsten Strasser
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Thomas Euler
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076, Tübingen, Germany
| | | | - Vasilica Nache
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany.
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13
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Sherpa RD, Hui SP. An insight on established retinal injury mechanisms and prevalent retinal stem cell activation pathways in vertebrate models. Animal Model Exp Med 2021; 4:189-203. [PMID: 34557646 PMCID: PMC8446703 DOI: 10.1002/ame2.12177] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 06/09/2021] [Indexed: 12/22/2022] Open
Abstract
Implementing different tools and injury mechanisms in multiple animal models of retina regeneration, researchers have discovered the existence of retinal stem/progenitor cells. Although they appear to be distributed uniformly across the vertebrate lineage, the reparative potential of the retina is mainly restricted to lower vertebrates. Regenerative repair post-injury requires the creation of a proliferative niche, vital for proper stem cell activation, propagation, and lineage differentiation. This seems to be lacking in mammals. Hence, in this review, we first discuss the many forms of retinal injuries that have been generated using animal models. Next, we discuss how they are utilized to stimulate regeneration and mimic eye disease pathologies. The key to driving stem cell activation in mammals relies on the information we can gather from these models. Lastly, we present a brief update about the genes, growth factors, and signaling pathways that have been brought to light using these models.
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Affiliation(s)
| | - Subhra Prakash Hui
- S. N. Pradhan Centre for NeurosciencesUniversity of CalcuttaKolkataIndia
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14
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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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15
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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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16
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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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17
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Splicing mutations in inherited retinal diseases. Prog Retin Eye Res 2021. [DOI: 10.1016/j.preteyeres.2020.100874
expr 921883647 + 833887994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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18
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Sacristan-Reviriego A, Le HM, Georgiou M, Meunier I, Bocquet B, Roux AF, Prodromou C, Bainbridge J, Michaelides M, van der Spuy J. Clinical and functional analyses of AIPL1 variants reveal mechanisms of pathogenicity linked to different forms of retinal degeneration. Sci Rep 2020; 10:17520. [PMID: 33067476 PMCID: PMC7567831 DOI: 10.1038/s41598-020-74516-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/21/2020] [Indexed: 12/18/2022] Open
Abstract
Disease-causing sequence variants in the highly polymorphic AIPL1 gene are associated with a broad spectrum of inherited retinal diseases ranging from severe autosomal recessive Leber congenital amaurosis to later onset retinitis pigmentosa. AIPL1 is a photoreceptor-specific co-chaperone that interacts with HSP90 to facilitate the stable assembly of retinal cGMP phosphodiesterase, PDE6. In this report, we establish unequivocal correlations between patient clinical phenotypes and in vitro functional assays of uncharacterized AIPL1 variants. We confirm that missense and nonsense variants in the FKBP-like and tetratricopeptide repeat domains of AIPL1 lead to the loss of both HSP90 interaction and PDE6 activity, confirming these variants cause LCA. In contrast, we report the association of p.G122R with milder forms of retinal degeneration, and show that while p.G122R had no effect on HSP90 binding, the modulation of PDE6 cGMP levels was impaired. The clinical history of these patients together with our functional assays suggest that the p.G122R variant is a rare hypomorphic allele with a later disease onset, amenable to therapeutic intervention. Finally, we report the primate-specific proline-rich domain to be dispensable for both HSP90 interaction and PDE6 activity. We conclude that variants investigated in this domain do not cause disease, with the exception of p.A352_P355del associated with autosomal dominant cone-rod dystrophy.
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Affiliation(s)
| | - Hoang Mai Le
- UCL Institute of Ophthalmology, University College London, 11 - 43 Bath Street, London, EC1V 9EL, UK
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, 11 - 43 Bath Street, London, EC1V 9EL, UK.,Moorfields Eye Hospital, City Road, London, EC1V 2PD, UK
| | - Isabelle Meunier
- Centre National de Référence Maladies Sensorielles Génétiques, Service Ophtalmologie Hôpital Gui de Chauliac - CHRU de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
| | - Beatrice Bocquet
- Centre National de Référence Maladies Sensorielles Génétiques, Service Ophtalmologie Hôpital Gui de Chauliac - CHRU de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
| | - Anne-Françoise Roux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | | | - James Bainbridge
- UCL Institute of Ophthalmology, University College London, 11 - 43 Bath Street, London, EC1V 9EL, UK.,Moorfields Eye Hospital, City Road, London, EC1V 2PD, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, 11 - 43 Bath Street, London, EC1V 9EL, UK.,Moorfields Eye Hospital, City Road, London, EC1V 2PD, UK
| | - Jacqueline van der Spuy
- UCL Institute of Ophthalmology, University College London, 11 - 43 Bath Street, London, EC1V 9EL, UK.
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19
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Identification of Key Genes and Pathways Associated with Age-Related Macular Degeneration. J Ophthalmol 2020; 2020:2714746. [PMID: 32904543 PMCID: PMC7456487 DOI: 10.1155/2020/2714746] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 07/16/2020] [Accepted: 07/28/2020] [Indexed: 01/27/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of severe, permanent vision loss among the elderly in the developed world. The cellular and molecular pathogenesis of initiation and development of AMD remain poorly delineated. The limited resources of the human AMD RPE/choroid tissues impeded the extensive study of the disease. To better understand the molecular and pathway changes in human AMD RPE/choroid tissues, we searched the literature and found three independent studies using high-throughput technology to analyze gene expression in 54 human AMD RPE/choroid tissues and 46 age-matched healthy controls. We downloaded these data, pooled them together, and reanalyzed the difference between molecular and pathways by the Ingenuity Pathway Analysis (IPA) database. Totally, 353 differentially expressed genes (DEGs) were identified, among which 181 genes were downregulated and 172 genes were upregulated in RPE/choroid of AMD patients. Furthermore, several significantly enriched biological processes, including cancer, organismal injury and abnormalities, and ophthalmic disease, were identified associated with these DEGs. By analysis of canonical pathway, the phototransduction pathway and atherosclerosis signaling were the top two significant canonical pathways altered in RPE/choroid tissues in human AMD. As expected, several ophthalmic disease-related molecules, including RHO, PDE6A, 3',5'-cyclic-GMP phosphodiesterase, and G protein alpha, were in the central nodes of disease network. The bioinformatics technology combined with the existing high-throughput data was applied to evaluate the underlying key genes and pathways in human AMD tissues, which may predict downstream and upstream biological processes and identify potential therapeutic intervention targets in human AMD.
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20
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Splicing mutations in inherited retinal diseases. Prog Retin Eye Res 2020; 80:100874. [PMID: 32553897 DOI: 10.1016/j.preteyeres.2020.100874] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 05/30/2020] [Accepted: 05/31/2020] [Indexed: 12/15/2022]
Abstract
Mutations which induce aberrant transcript splicing represent a distinct class of disease-causing genetic variants in retinal disease genes. Such mutations may either weaken or erase regular splice sites or create novel splice sites which alter exon recognition. While mutations affecting the canonical GU-AG dinucleotides at the splice donor and splice acceptor site are highly predictive to cause a splicing defect, other variants in the vicinity of the canonical splice sites or those affecting additional cis-acting regulatory sequences within exons or introns are much more difficult to assess or even to recognize and require additional experimental validation. Splicing mutations are unique in that the actual outcome for the transcript (e.g. exon skipping, pseudoexon inclusion, intron retention) and the encoded protein can be quite different depending on the individual mutation. In this article, we present an overview on the current knowledge about and impact of splicing mutations in inherited retinal diseases. We introduce the most common sub-classes of splicing mutations including examples from our own work and others and discuss current strategies for the identification and validation of splicing mutations, as well as therapeutic approaches, open questions, and future perspectives in this field of research.
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21
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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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Pontikos N, Murphy C, Moghul I, Arno G, Fujinami K, Fujinami Y, Sumodhee D, Downes S, Webster A, Yu J. Phenogenon: Gene to phenotype associations for rare genetic diseases. PLoS One 2020; 15:e0230587. [PMID: 32271766 PMCID: PMC7144978 DOI: 10.1371/journal.pone.0230587] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/03/2020] [Indexed: 11/30/2022] Open
Abstract
As high-throughput sequencing is increasingly applied to the molecular diagnosis of rare Mendelian disorders, a large number of patients with diverse phenotypes have their genetic and phenotypic data pooled together to uncover new gene-phenotype relations. We introduce Phenogenon, a statistical tool that combines, Human Phenotype Ontology (HPO) annotated patient phenotypes, gnomAD allele population frequency, and Combined Annotation Dependent Depletion (CADD) score for variant pathogenicity, in order to jointly predict the mode of inheritance and gene-phenotype associations. We ran Phenogenon on our cohort of 3,290 patients who had undergone whole exome sequencing. Among the top associations, we recapitulated previously known, such as "SRD5A3—Abnormal full-field electroretinogram—recessive" and "GRHL2 –Nail dystrophy—recessive", and discovered one potentially novel, “RRAGA–Abnormality of the skin—dominant”. We also developed an interactive web interface available at https://phenogenon.phenopolis.org to visualise and explore the results.
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Affiliation(s)
- Nikolas Pontikos
- UCL Genetics Institute, University College London, London, United Kingdom
- Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Cian Murphy
- UCL Genetics Institute, University College London, London, United Kingdom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Ismail Moghul
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Gavin Arno
- Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Kaoru Fujinami
- Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Yu Fujinami
- Graduate School of Health Management, Keio University, Tokyo, Japan
- Division of Public Health, Yokokawa Clinic, Osaka, Japan
| | - Dayyanah Sumodhee
- Queen Mary University, Mile End Road, Bethnal Green, London, United Kingdom
| | - Susan Downes
- Oxford Eye Hospital, West Wing, John Radcliffe Hospital, Oxford, United Kingdom
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Andrew Webster
- Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Jing Yu
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
- * E-mail:
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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: 36] [Impact Index Per Article: 9.0] [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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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: 27] [Impact Index Per Article: 6.8] [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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25
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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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26
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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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27
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Maryam A, Vedithi SC, Khalid RR, Alsulami AF, Torres PHM, Siddiqi AR, Blundell TL. The Molecular Organization of Human cGMP Specific Phosphodiesterase 6 (PDE6): Structural Implications of Somatic Mutations in Cancer and Retinitis Pigmentosa. Comput Struct Biotechnol J 2019; 17:378-389. [PMID: 30962868 PMCID: PMC6434069 DOI: 10.1016/j.csbj.2019.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/24/2019] [Accepted: 03/03/2019] [Indexed: 01/12/2023] Open
Abstract
In the cyclic guanosine monophosphate (cGMP) signaling pathway, phosphodiesterase 6 (PDE6) maintains a critical balance of the intracellular concentration of cGMP by catalyzing it to 5′ guanosine monophosphate (5′-GMP). To gain insight into the mechanistic impacts of the PDE6 somatic mutations that are implicated in cancer and retinitis pigmentosa, we first defined the structure and organization of the human PDE6 heterodimer using computational comparative modelling. Each subunit of PDE6αβ possesses three domains connected through long α-helices. The heterodimer model indicates that the two chains are likely related by a pseudo two-fold axis. The N-terminal region of each subunit is comprised of two allosteric cGMP-binding domains (Gaf-A & Gaf-B), oriented in the same way and interacting with the catalytic domain present at the C-terminal in a way that would allow the allosteric cGMP-binding domains to influence catalytic activity. Subsequently, we applied an integrated knowledge-driven in silico mutation analysis approach to understand the structural and functional implications of experimentally identified mutations that cause various cancers and retinitis pigmentosa, as well as computational saturation mutagenesis of the dimer interface and cGMP-binding residues of both Gaf-A, and the catalytic domains. We studied the impact of mutations on the stability of PDE6αβ structure, subunit-interfaces and Gaf-cGMP interactions. Further, we discussed the changes in interatomic interactions of mutations that are destabilizing in Gaf-A (R93L, V141 M, F162 L), catalytic domain (D600N, F742 L, F776 L) and at the dimer interface (F426A, F248G, F424 N). This study establishes a possible link of change in PDE6αβ structural stability to the experimentally observed disease phenotypes.
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Affiliation(s)
- Arooma Maryam
- Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Islamabad, Pakistan.,Department of Biochemistry, University of Cambridge, 80 Tennis Court Rd, Cambridge CB2 1GA, UK
| | | | - Rana Rehan Khalid
- Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Islamabad, Pakistan
| | - Ali F Alsulami
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Rd, Cambridge CB2 1GA, UK
| | | | - Abdul Rauf Siddiqi
- Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Islamabad, Pakistan
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Rd, Cambridge CB2 1GA, UK
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Abstract
Malaria is a causative factor in about 500.000 deaths each year world-wide. Cerebral malaria is a particularly severe complication of this disease and thus associated with an exceedingly high mortality. Malaria retinopathy is an ocular manifestation often associated with cerebral malaria, and presumably shares a substantial part of its pathophysiology. Here, we describe that indeed murine malaria retinopathy reproduced the main hallmarks of the corresponding human disease. In the living animal, we were able to follow the circulation and cellular localization of malaria parasites transgenically labelled with GFP via non-invasive in vivo retinal imaging. We found that malaria parasites cross the blood-retinal-barrier and infiltrate the neuroretina, concomitant with an extensive, irreversible, and long-lasting retinal neurodegeneration. Furthermore, anti-malarial treatment with dihydroartemisinin strongly diminished the load of circulating parasites but resolved the symptoms of the retinopathy only in part. In summary, we introduce here a novel preclinical model for human cerebral malaria that is much more directly accessible for studies into disease pathophysiology and development of novel treatment approaches. In vivo retinal imaging may furthermore serve as a valuable tool for the early diagnosis of the human disease.
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29
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Abstract
Full-field electroretinography (ERG) belongs to the gold-standard of electrophysiological test systems in ophthalmology and reflects the sum response of the entire retina to light stimulation. The assessment of the retinal function is a fundamental diagnostic technique not only in the clinical ophthalmology it is also indispensable in the ophthalmic research, in particular, in therapeutic approaches where the in vivo follow up of the benefit after treatment is absolutely necessary. Several current therapeutic approaches have demonstrated long-lasting amelioration in respective disease models and show promise for a successful translation to human patients. In this chapter we provide electroretinography protocols of experimental data which may serve as informative features for upcoming gene therapeutic approaches and clinical trials.
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30
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Pyruvate kinase M2 regulates photoreceptor structure, function, and viability. Cell Death Dis 2018; 9:240. [PMID: 29445082 PMCID: PMC5833680 DOI: 10.1038/s41419-018-0296-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/18/2017] [Accepted: 12/27/2017] [Indexed: 01/30/2023]
Abstract
Pyruvate kinase M2 (PKM2) is a glycolytic enzyme that is expressed in cancer cells. Its role in tumor metabolism is not definitively established, but investigators have suggested that regulation of PKM2 activity can cause accumulation of glycolytic intermediates and increase flux through the pentose phosphate pathway. Recent evidence suggests that PKM2 also may have non-metabolic functions, including as a transcriptional co-activator in gene regulation. We reported previously that PKM2 is abundant in photoreceptor cells in mouse retinas. In the present study, we conditionally deleted PKM2 (rod-cre PKM2-KO) in rod photoreceptors and found that the absence of PKM2 causes increased expression of PKM1 in rods. Analysis of metabolic flux from U-13C glucose shows that rod-cre PKM2-KO retinas accumulate glycolytic intermediates, consistent with an overall reduction in the amount of pyruvate kinase activity. Rod-cre PKM2-KO mice also have an increased NADPH availability could favor lipid synthesis, but we found no difference in phospholipid synthesis between rod-cre PKM2 KO and PKM2-positive controls. As rod-cre PKM2-KO mice aged, we observed a significant loss of rod function, reduced thickness of the photoreceptor outer segment layer, and reduced expression of photoreceptor proteins, including PDE6β. The rod-cre PKM2-KO retinas showed greater TUNEL staining than wild-type retinas, indicating a slow retinal degeneration. In vitro analysis showed that PKM2 can regulate transcriptional activity from the PDE6β promoter in vitro. Our findings indicate that both the metabolic and transcriptional regulatory functions of PKM2 may contribute to photoreceptor structure, function, and viability.
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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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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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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] [Grants] [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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Nair P, Hamzeh AR, Malik EM, Oberoi D, Al-Ali MT, Bastaki F. Novel PDE6A mutation in an Emirati patient with retinitis pigmentosa. Oman J Ophthalmol 2017; 10:228-231. [PMID: 29118501 PMCID: PMC5657168 DOI: 10.4103/ojo.ojo_213_2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mutations in the PDE6A gene are known to cause a form of retinitis pigmentosa (RP43), characterized by progressive retinal degeneration. We describe an Emirati patient with RP caused by a novel mutation in PDE6A. Clinical diagnosis of RP was made based on clinical evaluation and electroretinograms. The molecular analysis involved performing whole-exome sequencing, which enabled the identification of a homozygous 2-bp deletion (c.1358_1359delAT) in PDE6A, which was predicted to result in a frameshift and premature termination (p.Ile452Serfs*7). The mutation completely removed the catalytic PDEase domain in the protein. The parents were found to be heterozygous carriers of the variant. We thus report the first known case of a pathological variant in the PDE6A gene from the Arabian Peninsula.
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Affiliation(s)
| | | | - Ethar Mustafa Malik
- Department of Pediatric, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | | | | | - Fatma Bastaki
- Department of Pediatric, Latifa Hospital, Dubai Health Authority, Dubai, UAE
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TNFa knockdown in the retina promotes cone survival in a mouse model of autosomal dominant retinitis pigmentosa. Biochim Biophys Acta Mol Basis Dis 2016; 1863:92-102. [PMID: 27750040 DOI: 10.1016/j.bbadis.2016.10.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 10/06/2016] [Accepted: 10/13/2016] [Indexed: 12/22/2022]
Abstract
Expression of T17M rhodopsin (T17M) in rods activates the Unfolded Protein Response (UPR) and leads to the development of autosomal dominant retinitis pigmentosa (adRP). The rod death occurs in adRP retinas prior to cone photoreceptor death, so the mechanism by which cone photoreceptors die remains unclear. Therefore, the goal of the study was to verify whether UPR in rods induces TNFa-mediated signaling to the cones and to determine whether the TNFa deficit could prevent adRP cone cell death. Primary rod photoreceptors and cone-derived 661W cells transfected with siRNA against TNFa were treated with tunicamycin to mimic activation of UPR in T17M retinas expressing normal and reduced TNFa levels. The 661W cells were then exposed to recombinant TNFa to evaluate cell viability. In vivo, the role of TNFa was assessed in T17M TNFa+/- mice by electroretinography, optical coherence tomography, histology, immunohistochemistry, and a cytokine enzyme-linked immunosorbent assay. Rods overexpressed and secreted TNFa in response to UPR activation. The recombinant TNFa treatment lowered the number of viable cones, inducing cell death through elevation of pro-inflammatory cytokines and caspase-3/7 activity. The TNFa deficiency significantly protected adRP retinas. The photopic ERG amplitudes and the number of surviving cones dramatically increased in T17M TNFa+/- mice. This neuroprotection was associated with a reduced level of pro-inflammatory cytokines. Our results indicate that rod photoreceptors, following UPR activation during adRP progression, secrete TNFa and signal a self-destructive program to the cones, resulting in their cell death. TNFa therefore holds promise as a therapeutic target for treatment of adRP.
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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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Comitato A, Di Salvo MT, Turchiano G, Montanari M, Sakami S, Palczewski K, Marigo V. Dominant and recessive mutations in rhodopsin activate different cell death pathways. Hum Mol Genet 2016; 25:2801-2812. [PMID: 27149983 DOI: 10.1093/hmg/ddw137] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/05/2016] [Accepted: 04/25/2016] [Indexed: 12/25/2022] Open
Abstract
Mutations in rhodopsin (RHO) are a common cause of retinal dystrophy and can be transmitted by dominant or recessive inheritance. Clinical symptoms caused by dominant and recessive mutations in patients and animal models are very similar but the molecular mechanisms leading to retinal degeneration may differ. We characterized three murine models of retina degeneration caused by either Rho loss of function or expression of the P23H dominant mutation in Rho. Rho loss of function is characterized by activation of calpains and apoptosis-inducing factor (Aif) in dying photoreceptors. Retinas bearing the P23H dominant mutations activate both the calpain-Aif cell death pathway and ER-stress responses that together contribute to photoreceptor cell demise. In vivo treatment with the calpastatin peptide, a calpain inhibitor, was strongly neuroprotective in mice lacking Rho while photoreceptor survival in retinas expressing the P23H dominant mutation was more affected by treatment with salubrinal, an inhibitor of the ER-stress pathway. The further reduction of photoreceptor cell demise by co-treatment with calpastatin and salubrinal suggests co-activation of the calpain and ER-stress death pathways in mice bearing dominant mutations in the Rho gene.
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Affiliation(s)
- Antonella Comitato
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Maria Teresa Di Salvo
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Giandomenico Turchiano
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Monica Montanari
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Sanae Sakami
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
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Schön C, Asteriti S, Koch S, Sothilingam V, Garrido MG, Tanimoto N, Herms J, Seeliger MW, Cangiano L, Biel M, Michalakis S. Loss of HCN1 enhances disease progression in mouse models of CNG channel-linked retinitis pigmentosa and achromatopsia. Hum Mol Genet 2016; 25:1165-75. [DOI: 10.1093/hmg/ddv639] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/22/2015] [Indexed: 01/24/2023] Open
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