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Nolan ND, Cui X, Robbings BM, Demirkol A, Pandey K, Wu WH, Hu HF, Jenny LA, Lin CS, Hass DT, Du J, Hurley JB, Tsang SH. CRISPR editing of anti-anemia drug target rescues independent preclinical models of retinitis pigmentosa. Cell Rep Med 2024; 5:101459. [PMID: 38518771 PMCID: PMC11031380 DOI: 10.1016/j.xcrm.2024.101459] [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: 07/07/2023] [Revised: 12/21/2023] [Accepted: 02/14/2024] [Indexed: 03/24/2024]
Abstract
Retinitis pigmentosa (RP) is one of the most common forms of hereditary neurodegeneration. It is caused by one or more of at least 3,100 mutations in over 80 genes that are primarily expressed in rod photoreceptors. In RP, the primary rod-death phase is followed by cone death, regardless of the underlying gene mutation that drove the initial rod degeneration. Dampening the oxidation of glycolytic end products in rod mitochondria enhances cone survival in divergent etiological disease models independent of the underlying rod-specific gene mutations. Therapeutic editing of the prolyl hydroxylase domain-containing protein gene (PHD2, also known as Egln1) in rod photoreceptors led to the sustained survival of both diseased rods and cones in both preclinical autosomal-recessive and dominant RP models. Adeno-associated virus-mediated CRISPR-based therapeutic reprogramming of the aerobic glycolysis node may serve as a gene-agnostic treatment for patients with various forms of RP.
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Affiliation(s)
- Nicholas D Nolan
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, Columbia Stem Cell Initiative, New York, NY 10032, USA; Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA; Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Xuan Cui
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, Columbia Stem Cell Initiative, New York, NY 10032, USA; Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Brian M Robbings
- Department of Biochemistry, The University of Washington, Seattle, WA 98195, USA; Diabetes Institute, The University of Washington, Seattle, WA 98195, USA
| | - Aykut Demirkol
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, Columbia Stem Cell Initiative, New York, NY 10032, USA; Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA; Vocational School of Health Services, Uskudar University, 34672 Istanbul, Turkey
| | - Kriti Pandey
- Department of Biochemistry, The University of Washington, Seattle, WA 98195, USA
| | - Wen-Hsuan Wu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, Columbia Stem Cell Initiative, New York, NY 10032, USA; Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Hannah F Hu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, Columbia Stem Cell Initiative, New York, NY 10032, USA; Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA; Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Laura A Jenny
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, Columbia Stem Cell Initiative, New York, NY 10032, USA; Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Chyuan-Sheng Lin
- Herbert Irving Comprehensive Cancer Center, Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Departments of Ophthalmology, Pathology & Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Daniel T Hass
- Department of Biochemistry, The University of Washington, Seattle, WA 98195, USA
| | - Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV 26506, USA; Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV 26501, USA
| | - James B Hurley
- Department of Biochemistry, The University of Washington, Seattle, WA 98195, USA.
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, Columbia Stem Cell Initiative, New York, NY 10032, USA; Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA; Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA; Departments of Ophthalmology, Pathology & Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA.
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Chien Y, Hsiao YJ, Chou SJ, Lin TY, Yarmishyn AA, Lai WY, Lee MS, Lin YY, Lin TW, Hwang DK, Lin TC, Chiou SH, Chen SJ, Yang YP. Nanoparticles-mediated CRISPR-Cas9 gene therapy in inherited retinal diseases: applications, challenges, and emerging opportunities. J Nanobiotechnology 2022; 20:511. [DOI: 10.1186/s12951-022-01717-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/23/2022] [Indexed: 12/04/2022] Open
Abstract
AbstractInherited Retinal Diseases (IRDs) are considered one of the leading causes of blindness worldwide. However, the majority of them still lack a safe and effective treatment due to their complexity and genetic heterogeneity. Recently, gene therapy is gaining importance as an efficient strategy to address IRDs which were previously considered incurable. The development of the clustered regularly-interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has strongly empowered the field of gene therapy. However, successful gene modifications rely on the efficient delivery of CRISPR-Cas9 components into the complex three-dimensional (3D) architecture of the human retinal tissue. Intriguing findings in the field of nanoparticles (NPs) meet all the criteria required for CRISPR-Cas9 delivery and have made a great contribution toward its therapeutic applications. In addition, exploiting induced pluripotent stem cell (iPSC) technology and in vitro 3D retinal organoids paved the way for prospective clinical trials of the CRISPR-Cas9 system in treating IRDs. This review highlights important advances in NP-based gene therapy, the CRISPR-Cas9 system, and iPSC-derived retinal organoids with a focus on IRDs. Collectively, these studies establish a multidisciplinary approach by integrating nanomedicine and stem cell technologies and demonstrate the utility of retina organoids in developing effective therapies for IRDs.
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Rowe AA, Chen X, Nettesheim ER, Issioui Y, Dong T, Hu Y, Messahel S, Kayani SN, Gray SJ, Wert KJ. Long-term progression of retinal degeneration in a preclinical model of CLN7 Batten disease as a baseline for testing clinical therapeutics. EBioMedicine 2022; 85:104314. [PMID: 36374771 PMCID: PMC9626557 DOI: 10.1016/j.ebiom.2022.104314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 09/22/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Batten disease is characterized by cognitive and motor impairment, retinal degeneration, and seizures leading to premature death. Recent studies have shown efficacy for a gene therapy approach for CLN7 Batten disease. This gene therapy approach is promising to treat cognitive and motor impairment, but is not likely to delay vision loss. Additionally, the natural progression of retinal degeneration in CLN7 Batten disease patients is not well-known. METHODS We performed visual examinations on five patients with CLN7 Batten disease and found that patients were far progressed in degeneration within their first five years of life. To better understand the disease progression, we characterized the retina of a preclinical mouse model of CLN7 Batten disease, through the age at which mice present with paralysis and premature death. FINDINGS We found that this preclinical model shows signs of photoreceptor to bipolar synaptic defects early, and displays rod-cone dystrophy with late loss of bipolar cells. This vision loss could be followed not only via histology, but using clinical live imaging similar to that used in human patients. INTERPRETATION Natural history studies of rare paediatric neurodegenerative conditions are complicated by the rapid degeneration and limited availability of patients. Characterization of degeneration in the preclinical model allows for future experiments to better understand the mechanisms underlying the retinal disease progression in order to find therapeutics to treat patients, as well as to evaluate these therapeutic options for future human clinical trials. FUNDING Van Sickle Family Foundation Inc., NIHP30EY030413, Morton Fichtenbaum Charitable Trust and 5T32GM131945-03.
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Affiliation(s)
- Ashley A Rowe
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xin Chen
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Peter O'Donnell Jr. Brain Institute, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Emily R Nettesheim
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Yacine Issioui
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Thomas Dong
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Yuhui Hu
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Souad Messahel
- Peter O'Donnell Jr. Brain Institute, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Saima N Kayani
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Peter O'Donnell Jr. Brain Institute, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Department of Neurology, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Children's Health, Children's Medical Center, Dallas, TX, 75390, USA
| | - Steven J Gray
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Department of Neurology, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA; McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Katherine J Wert
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Peter O'Donnell Jr. Brain Institute, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
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Wu S, Mao Y, Liu Q, Yan X, Zhang J, Wang N. Sustained Release of Gas6 via mPEG-PLGA Nanoparticles Enhances the Therapeutic Effects of MERTK Gene Therapy in RCS Rats. Front Med (Lausanne) 2022; 8:794299. [PMID: 34970569 PMCID: PMC8712650 DOI: 10.3389/fmed.2021.794299] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
Previous researches utilizing MER proto-oncogene tyrosine kinase (MERTK) gene therapy in Royal College of Surgeons (RCS) rats evidenced its effectiveness in treating MERTK-associated retinitis pigmentosa (RP). Specific ligands for receptor tyrosine kinases, such as growth arrest-specific 6 (Gas6), may enhance retinal phagocytosis via the MERTK receptor, and consequently, enhance the therapeutic effects of gene therapy. In order to overcome the short life effect of the injected Gas6 protein, we constructed a Gas6 loaded methoxy-poly (ethylene glyeol)-poly (lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles (Gas6 NPs) system which allowed for localized and sustained Gas6 protein release, and therefore, a prolonged biological effect. Our data demonstrated that Gas6 protein release from Gas6 NPs preserved the bioactivity and promoted retinal pigment epithelium (RPE) phagocytosis in vitro. In vivo studies showed that RCS rats in the hMERTK/Gas6 NPs group exhibiting the highest electroretinogram responses and more complete retinal structure than that in other groups, further demonstrating that the co-administration of AAV2-BEST1-hMERTK and Gas6 NPs could protect photoreceptors from degeneration. These findings strongly suggest that Gas6 NPs are a promising method to enable the sustained release of Gas6 protein and could therefore enhance the therapeutic effects of gene therapy for MERTK-associated RP.
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Affiliation(s)
- Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.,Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Yingyan Mao
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.,Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beijing Tongren Hospital, Beihang University, Capital Medical University, Beijing, China
| | - Qian Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.,Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Xuejing Yan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.,Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Jingxue Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.,Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China.,Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beijing Tongren Hospital, Beihang University, Capital Medical University, Beijing, China
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.,Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China.,Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beijing Tongren Hospital, Beihang University, Capital Medical University, Beijing, China
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5
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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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Bujakowska KM, Comander J. Moving Towards PDE6A Gene Supplementation Therapy. JAMA Ophthalmol 2020; 138:1251-1252. [PMID: 33057571 DOI: 10.1001/jamaophthalmol.2020.4216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Kinga M Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston
| | - Jason Comander
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston
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Zhang E, Ryu J, Levi SR, Oh JK, Hsu CW, Cui X, Lee TT, Wang NK, Lima de Carvalho JR, Tsang SH. PKM2 ablation enhanced retinal function and survival in a preclinical model of retinitis pigmentosa. Mamm Genome 2020; 31:77-85. [PMID: 32342224 DOI: 10.1007/s00335-020-09837-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/08/2020] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is a neurodegenerative disorder that causes irreversible vision loss in over 1.5 million individuals world-wide. The genetic heterogeneity of RP necessitates a broad therapy that is able to provide treatment in a gene- and mutation- non-specific manner. In this study, we identify the therapeutic benefits of metabolic reprogramming by targeting pyruvate kinase M2 (PKM2) in a Pde6β preclinical model of RP. The genetic contributions of PKM2 inhibition in retinal degeneration were evaluated through histology and electroretinogram (ERG) followed by a statistical analysis using a linear regression model. Notably, PKM2 ablation resulted in thicker retinal layers in Pde6β-mutated mice as compared to the controls, suggesting greater photoreceptor survival. Consistent with these anatomical findings, ERG analyses revealed that the maximum b-wave is on average greater in Pkm2 knockout mice than in mice with intact Pkm2, indicating enhanced photoreceptor function. These rescue phenotypes from Pkm2 ablation in a preclinical model of RP indicate that a metabolome reprogramming may be useful in treating RP.
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Affiliation(s)
- Ethan Zhang
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Joseph Ryu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Sarah R Levi
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Jin Kyun Oh
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- State University of New York At Downstate Medical Center, Brooklyn, NY, USA
| | - Chun Wei Hsu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Xuan Cui
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- The College of Optometry, Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Tianjin, China
| | - Ting-Ting Lee
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Nan-Kai Wang
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Jose Ronaldo Lima de Carvalho
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- Department of Ophthalmology, Empresa Brasileira de Servicos Hospitalares (EBSERH) - Hospital das Clinicas de Pernambuco (HCPE), Federal University of Pernambuco (UFPE), Recife, Brazil
- Department of Ophthalmology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.
- Department of Pathology & Cell Biology, Institute of Human Nutrition, and Columbia Stem Cell Initiative, Columbia University, New York, NY, USA.
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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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9
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Metabolite therapy guided by liquid biopsy proteomics delays retinal neurodegeneration. EBioMedicine 2020; 52:102636. [PMID: 32028070 PMCID: PMC7005447 DOI: 10.1016/j.ebiom.2020.102636] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/26/2019] [Accepted: 01/09/2020] [Indexed: 02/06/2023] Open
Abstract
Background Neurodegenerative diseases are incurable disorders caused by progressive neuronal cell death. Retinitis pigmentosa (RP) is a blinding neurodegenerative disease that results in photoreceptor death and progresses to the loss of the entire retinal network. We previously found that proteomic analysis of the adjacent vitreous served as way to indirectly biopsy the retina and identify changes in the retinal proteome. Methods We analyzed protein expression in liquid vitreous biopsies from autosomal recessive (ar)RP patients with PDE6A mutations and arRP mice with Pde6ɑ mutations. Proteomic analysis of retina and vitreous samples identified molecular pathways affected at the onset of photoreceptor death. Based on affected molecular pathways, arRP mice were treated with a ketogenic diet or metabolites involved in fatty-acid synthesis, oxidative phosphorylation, and the tricarboxylic acid (TCA) cycle. Findings Dietary supplementation of a single metabolite, ɑ-ketoglutarate, increased docosahexaeonic acid levels, provided neuroprotection, and enhanced visual function in arRP mice. A ketogenic diet delayed photoreceptor cell loss, while vitamin B supplementation had a limited effect. Finally, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) on ɑ-ketoglutarate-treated mice revealed restoration of metabolites that correlated with our proteomic findings: uridine, dihydrouridine, and thymidine (pyrimidine and purine metabolism), glutamine and glutamate (glutamine/glutamate conversion), and succinic and aconitic acid (TCA cycle). Interpretation This study demonstrates that replenishing TCA cycle metabolites via oral supplementation prolongs retinal function and provides a neuroprotective effect on the photoreceptor cells and inner retinal network. Funding NIH grants [R01EY026682, R01EY024665, R01EY025225, R01EY024698, R21AG050437, P30EY026877, 5P30EY019007, R01EY018213, F30EYE027986, T32GM007337, 5P30CA013696], NSF grant CHE-1734082.
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10
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Baillie GS, Tejeda GS, Kelly MP. Therapeutic targeting of 3',5'-cyclic nucleotide phosphodiesterases: inhibition and beyond. Nat Rev Drug Discov 2019; 18:770-796. [PMID: 31388135 PMCID: PMC6773486 DOI: 10.1038/s41573-019-0033-4] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2019] [Indexed: 01/24/2023]
Abstract
Phosphodiesterases (PDEs), enzymes that degrade 3',5'-cyclic nucleotides, are being pursued as therapeutic targets for several diseases, including those affecting the nervous system, the cardiovascular system, fertility, immunity, cancer and metabolism. Clinical development programmes have focused exclusively on catalytic inhibition, which continues to be a strong focus of ongoing drug discovery efforts. However, emerging evidence supports novel strategies to therapeutically target PDE function, including enhancing catalytic activity, normalizing altered compartmentalization and modulating post-translational modifications, as well as the potential use of PDEs as disease biomarkers. Importantly, a more refined appreciation of the intramolecular mechanisms regulating PDE function and trafficking is emerging, making these pioneering drug discovery efforts tractable.
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Affiliation(s)
- George S Baillie
- Institute of Cardiovascular and Medical Science, University of Glasgow, Glasgow, UK
| | - Gonzalo S Tejeda
- Institute of Cardiovascular and Medical Science, University of Glasgow, Glasgow, UK
| | - Michy P Kelly
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA.
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11
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Wert KJ, Koch SF, Velez G, Hsu CW, Mahajan M, Bassuk AG, Tsang SH, Mahajan VB. CAPN5 genetic inactivation phenotype supports therapeutic inhibition trials. Hum Mutat 2019; 40:2377-2392. [PMID: 31403230 DOI: 10.1002/humu.23894] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 07/20/2019] [Accepted: 08/09/2019] [Indexed: 01/08/2023]
Abstract
Small molecule pharmacological inhibition of dominant human genetic disease is a feasible treatment that does not rely on the development of individual, patient-specific gene therapy vectors. However, the consequences of protein inhibition as a clinical therapeutic are not well-studied. In advance of human therapeutic trials for CAPN5 vitreoretinopathy, genetic inactivation can be used to infer the effect of protein inhibition in vivo. We created a photoreceptor-specific knockout (KO) mouse for Capn5 and compared the retinal phenotype to both wild-type and an existing Capn5 KO mouse model. In humans, CAPN5 loss-of-function (LOF) gene variants were ascertained in large exome databases from 60,706 unrelated subjects without severe disease phenotypes. Ocular examination of the retina of Capn5 KO mice by histology and electroretinography showed no significant abnormalities. In humans, there were 22 LOF CAPN5 variants located throughout the gene and in all major protein domains. Structural modeling of coding variants showed these LOF variants were nearby known disease-causing variants within the proteolytic core and in regions of high homology between human CAPN5 and 150 homologs, yet the LOF of CAPN5 was tolerated as opposed to gain-of-function disease-causing variants. These results indicate that localized inhibition of CAPN5 is a viable strategy for hyperactivating disease alleles.
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Affiliation(s)
- Katherine J Wert
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California
| | - Susanne F Koch
- Department of Physiological Genomics, Biomedical Center, Ludwig Maximillian University, Munich, Germany
| | - Gabriel Velez
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California.,Department of Ophthalmology, Medical Scientist Training Program, University of Iowa, Iowa City, Iowa
| | - Chun-Wei Hsu
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York Presbyterian Hospital, New York, New York.,Departments of Ophthalmology, Pathology, and Cell Biology, Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia Stem Cell Initiative (CSCI), Columbia University, New York, New York
| | - MaryAnn Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California
| | | | - Stephen H Tsang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York Presbyterian Hospital, New York, New York.,Departments of Ophthalmology, Pathology, and Cell Biology, Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia Stem Cell Initiative (CSCI), Columbia University, New York, New York
| | - Vinit B Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California.,Department of Ophthalmology, Veterans Affairs, Palo Alto Health Care System, Palo Alto, California
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12
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Ye H, Xia XP. Visual field mean deviation and relevant factors in 928 Chinese retinitis pigmentosa patients. Int J Ophthalmol 2018; 11:1978-1983. [PMID: 30588433 DOI: 10.18240/ijo.2018.12.17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/07/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate the associations between demographic and clinical factors with the rate of visual field mean derivation (MD) decline in retinitis pigmentosa (RP) patients. METHODS Correlations of MDs with the visual acuity and retinal pigmentation were analyzed in 928 RP patients. MD decreasing rate in 10y and potential influences of gender, age, family history and retinal pigmentation on the rate were explored in 201 RP patients. RESULTS In the 928 patients, average MD and visual acuity were -14.44±8.61 dB and 0.79±0.35 respectively and when MD was lower than -9.18 dB the visual acuity would be below 1.0 (20/20). The average MD medium between eyes with or without retinal pigmentation was -14.82 dB. In 123 non-pigmented eyes, the average MD were lower than the medium but in 153 pigmented eyes it was higher than that. In the 201 patients, the average decreasing value of MD in 10 years' period was -8.01±3.66 dB and the value were correlated to retinal pigmentation but not to gender, age or RP family history. CONCLUSION The rate of MD decline in RP eyes is significantly related to retinal pigmentation. Our study demonstrates the quantitative rate of MD decline in RP patients and the value of MD could well reflect the severity of RP.
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Affiliation(s)
- Hui Ye
- Department of Ophthalmology, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province, China
| | - Xiao-Ping Xia
- Department of Ophthalmology, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province, China
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13
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Takahashi VKL, Takiuti JT, Jauregui R, Tsang SH. Gene therapy in inherited retinal degenerative diseases, a review. Ophthalmic Genet 2018; 39:560-568. [PMID: 30040511 DOI: 10.1080/13816810.2018.1495745] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hereditary diseases of the retina represent a group of diseases with several heterogeneous mutations that have the common end result of progressive photoreceptor death leading to blindness. Retinal degenerations encompass multifactorial diseases such as age-related macular degeneration, Leber congenital amaurosis, Stargardt disease, and retinitis pigmentosa. Although there is currently no cure for degenerative retinal diseases, ophthalmology has been at the forefront of the development of gene therapy, which offers hope for the treatment of these conditions. This article will explore an overview of the clinical trials of gene supplementation therapy for retinal diseases that are underway or planned for the near future.
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Affiliation(s)
- Vitor K L Takahashi
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,c Department of Ophthalmology , Federal University of São Paulo , São Paulo , Brazil
| | - Júlia T Takiuti
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,d Division of Ophthalmology , University of São Paulo Medical School , São Paulo , Brazil
| | - Ruben Jauregui
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,e Weill Cornell Medical College , New York , NY , USA
| | - Stephen H Tsang
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,f Department of Pathology & Cell Biology, Stem Cell Initiative (CSCI), Institute of Human Nutrition, College of Physicians and Surgeons , Columbia University , New York , NY , USA
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14
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Petit L, Ma S, Cheng SY, Gao G, Punzo C. Rod Outer Segment Development Influences AAV-Mediated Photoreceptor Transduction After Subretinal Injection. Hum Gene Ther 2018; 28:464-481. [PMID: 28510482 PMCID: PMC5488363 DOI: 10.1089/hum.2017.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Vectors based on the adeno-associated virus (AAV) are currently the preferred tools for delivering genes to photoreceptors (PR) in small and large animals. AAVs have been applied successfully in various models of PR dystrophies. However, unknown barriers still limit AAV's efficient application in several forms of severe PR degenerations due to insufficient transgene expression and/or treated cells at the time of injection. Optimizations of PR gene therapy strategies will likely benefit from the identification of the cellular factors that influence PR transduction. Interestingly, recent studies have shown that the AAV transduction profile of PRs differs significantly between neonatal and adult mouse retinas after subretinal injection. This phenomenon may provide clues to identify host factors that influence the efficiency of AAV-mediated PR transduction. This study demonstrates that rod outer segments are critical modulators of efficient AAV-mediated rod transduction. During retinal development, rod transduction correlated temporally and spatially with the differentiation order of PRs when vectors were introduced subretinally but not when introduced intravitreally. All subretinally injected vectors had an initial preference to transduce cones in the absence of formed rod outer segments and then displayed a preference for rods as the cells matured, independently of the expression cassette or AAV serotype. Consistent with this observation, altered development of rod outer segments was associated with a strong reduction of rod transduction and an increase in the percentage of transduced cones by 2- to 2.8-fold. A similar increase of cone transduction was observed in the adult retinal degeneration 1 (rd1) retina compared to wild-type mice. These results suggest that the loss of rod outer segments in diseased retinas could markedly affect gene transfer efficiency of AAV vectors by limiting the ability of AAVs to infect dying rods efficiently. This information could be exploited for the development of more efficient AAV-based PR gene delivery procedures.
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Affiliation(s)
- Lolita Petit
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Shan Ma
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Shun-Yun Cheng
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Guangping Gao
- 3 Department of Microbiology and Physiological Systems and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Claudio Punzo
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts.,2 Department of Neurobiology, University of Massachusetts Medical School , Worcester, Massachusetts
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15
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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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16
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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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17
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Farrar GJ, Carrigan M, Dockery A, Millington-Ward S, Palfi A, Chadderton N, Humphries M, Kiang AS, Kenna PF, Humphries P. Toward an elucidation of the molecular genetics of inherited retinal degenerations. Hum Mol Genet 2017; 26:R2-R11. [PMID: 28510639 PMCID: PMC5886474 DOI: 10.1093/hmg/ddx185] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 05/08/2017] [Indexed: 02/06/2023] Open
Abstract
While individually classed as rare diseases, hereditary retinal degenerations (IRDs) are the major cause of registered visual handicap in the developed world. Given their hereditary nature, some degree of intergenic heterogeneity was expected, with genes segregating in autosomal dominant, recessive, X-linked recessive, and more rarely in digenic or mitochondrial modes. Today, it is recognized that IRDs, as a group, represent one of the most genetically diverse of hereditary conditions - at least 260 genes having been implicated, with 70 genes identified in the most common IRD, retinitis pigmentosa (RP). However, targeted sequencing studies of exons from known IRD genes have resulted in the identification of candidate mutations in only approximately 60% of IRD cases. Given recent advances in the development of gene-based medicines, characterization of IRD patient cohorts for known IRD genes and elucidation of the molecular pathologies of disease in those remaining unresolved cases has become an endeavor of the highest priority. Here, we provide an outline of progress in this area.
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Affiliation(s)
- G Jane Farrar
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Matthew Carrigan
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Adrian Dockery
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Sophia Millington-Ward
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Arpad Palfi
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Naomi Chadderton
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Marian Humphries
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Anna Sophia Kiang
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Paul F Kenna
- Research Foundation, Royal Victoria Eye and Ear Hospital, Dublin 2, Ireland
| | - Pete Humphries
- Institute of Genetics, School of Genetics and Microbiology, University of Dublin, Trinity College, Dublin 2, Ireland
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Velez G, Tsang SH, Tsai YT, Hsu CW, Gore A, Abdelhakim AH, Mahajan M, Silverman RH, Sparrow JR, Bassuk AG, Mahajan VB. Gene Therapy Restores Mfrp and Corrects Axial Eye Length. Sci Rep 2017; 7:16151. [PMID: 29170418 PMCID: PMC5701072 DOI: 10.1038/s41598-017-16275-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 11/09/2017] [Indexed: 01/07/2023] Open
Abstract
Hyperopia (farsightedness) is a common and significant cause of visual impairment, and extreme hyperopia (nanophthalmos) is a consequence of loss-of-function MFRP mutations. MFRP deficiency causes abnormal eye growth along the visual axis and significant visual comorbidities, such as angle closure glaucoma, cystic macular edema, and exudative retinal detachment. The Mfrp rd6 /Mfrp rd6 mouse is used as a pre-clinical animal model of retinal degeneration, and we found it was also hyperopic. To test the effect of restoring Mfrp expression, we delivered a wild-type Mfrp to the retinal pigmented epithelium (RPE) of Mfrp rd6 /Mfrp rd6 mice via adeno-associated viral (AAV) gene therapy. Phenotypic rescue was evaluated using non-invasive, human clinical testing, including fundus auto-fluorescence, optical coherence tomography, electroretinography, and ultrasound. These analyses showed gene therapy restored retinal function and normalized axial length. Proteomic analysis of RPE tissue revealed rescue of specific proteins associated with eye growth and normal retinal and RPE function. The favorable response to gene therapy in Mfrp rd6 /Mfrp rd6 mice suggests hyperopia and associated refractive errors may be amenable to AAV gene therapy.
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Affiliation(s)
- Gabriel Velez
- Omics Laboratory, Stanford University, Palo Alto, CA, USA
- Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA, USA
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, USA
| | - Stephen H Tsang
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA.
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.
| | - Yi-Ting Tsai
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Chun-Wei Hsu
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Anuradha Gore
- Omics Laboratory, Stanford University, Palo Alto, CA, USA
| | - Aliaa H Abdelhakim
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | | | - Ronald H Silverman
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Janet R Sparrow
- Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Alexander G Bassuk
- Department of Pediatrics, University of Iowa, Iowa City, IA, USA.
- Department of Neurology, University of Iowa, Iowa City, IA, USA.
- Palo Alto Veterans Administration, Palo Alto, CA, USA.
| | - Vinit B Mahajan
- Omics Laboratory, Stanford University, Palo Alto, CA, USA.
- Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA, USA.
- Department of Neurology, University of Iowa, Iowa City, IA, USA.
- Palo Alto Veterans Administration, Palo Alto, CA, USA.
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19
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Hanlon KS, Chadderton N, Palfi A, Blanco Fernandez A, Humphries P, Kenna PF, Millington-Ward S, Farrar GJ. A Novel Retinal Ganglion Cell Promoter for Utility in AAV Vectors. Front Neurosci 2017; 11:521. [PMID: 28983234 PMCID: PMC5613148 DOI: 10.3389/fnins.2017.00521] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 09/04/2017] [Indexed: 12/13/2022] Open
Abstract
Significant advances in gene therapy have enabled exploration of therapies for inherited retinal disorders, many of which are in preclinical development or clinical evaluation. Gene therapy for retinal conditions has led the way in this growing field. The loss of retinal ganglion cells (RGCs) is a hallmark of a number of retinal disorders. As the field matures innovations that aid in refining therapies and optimizing efficacy are in demand. Gene therapies under development for RGC-related disorders, when delivered with recombinant adeno associated vectors (AAV), have typically been expressed from ubiquitous promoter sequences. Here we describe how a novel promoter from the murine Nefh gene was selected to drive transgene expression in RGCs. The Nefh promoter, in an AAV2/2 vector, was shown to drive preferential EGFP expression in murine RGCs in vivo following intravitreal injection. In contrast, EGFP expression from a CMV promoter was observed not only in RGCs, but throughout the inner nuclear layer and in amacrine cells located within the ganglion cell layer (GCL). Of note, the Nefh promoter sequence is sufficiently compact to be readily accommodated in AAV vectors, where transgene size represents a significant constraint. Moreover, this promoter should in principle provide a more targeted and potentially safer alternative for RGC-directed gene therapies.
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Affiliation(s)
- Killian S Hanlon
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Naomi Chadderton
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Arpad Palfi
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | | | - Peter Humphries
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Paul F Kenna
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland.,Research Foundation, Royal Victoria Eye and Ear HospitalDublin, Ireland
| | - Sophia Millington-Ward
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - G Jane Farrar
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
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20
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Mowat FM, Occelli LM, Bartoe JT, Gervais KJ, Bruewer AR, Querubin J, Dinculescu A, Boye SL, Hauswirth WW, Petersen-Jones SM. Gene Therapy in a Large Animal Model of PDE6A-Retinitis Pigmentosa. Front Neurosci 2017; 11:342. [PMID: 28676737 PMCID: PMC5476745 DOI: 10.3389/fnins.2017.00342] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/01/2017] [Indexed: 12/13/2022] Open
Abstract
Despite mutations in the rod phosphodiesterase 6-alpha (PDE6A) gene being well-recognized as a cause of human retinitis pigmentosa, no definitive treatments have been developed to treat this blinding disease. We performed a trial of retinal gene augmentation in the Pde6a mutant dog using Pde6a delivery by capsid-mutant adeno-associated virus serotype 8, previously shown to have a rapid onset of transgene expression in the canine retina. Subretinal injections were performed in 10 dogs at 29–44 days of age, and electroretinography and vision testing were performed to assess functional outcome. Retinal structure was assessed using color fundus photography, spectral domain optical coherence tomography, and histology. Immunohistochemistry was performed to examine transgene expression and expression of other retinal genes. Treatment resulted in improvement in dim light vision and evidence of rod function on electroretinographic examination. Photoreceptor layer thickness in the treated area was preserved compared with the contralateral control vector treated or uninjected eye. Improved rod and cone photoreceptor survival, rhodopsin localization, cyclic GMP levels and bipolar cell dendrite distribution was observed in treated areas. Some adverse effects including foci of retinal separation, foci of retinal degeneration and rosette formation were identified in both AAV-Pde6a and control vector injected regions. This is the first description of successful gene augmentation for Pde6a retinitis pigmentosa in a large animal model. Further studies will be necessary to optimize visual outcomes and minimize complications before translation to human studies.
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Affiliation(s)
- Freya M Mowat
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State UniversityRaleigh, NC, United States
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Joshua T Bartoe
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Kristen J Gervais
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Ashlee R Bruewer
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Janice Querubin
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
| | - Astra Dinculescu
- Department of Ophthalmology, University of Florida College of MedicineGainesville, FL, United States
| | - Sanford L Boye
- Department of Ophthalmology, University of Florida College of MedicineGainesville, FL, United States
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida College of MedicineGainesville, FL, United States
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State UniversityEast Lansing, MI, United States
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21
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Zhang L, Du J, Justus S, Hsu CW, Bonet-Ponce L, Wu WH, Tsai YT, Wu WP, Jia Y, Duong JK, Mahajan VB, Lin CS, Wang S, Hurley JB, Tsang SH. Reprogramming metabolism by targeting sirtuin 6 attenuates retinal degeneration. J Clin Invest 2016; 126:4659-4673. [PMID: 27841758 DOI: 10.1172/jci86905] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 10/06/2016] [Indexed: 12/16/2022] Open
Abstract
Retinitis pigmentosa (RP) encompasses a diverse group of Mendelian disorders leading to progressive degeneration of rods and then cones. For reasons that remain unclear, diseased RP photoreceptors begin to deteriorate, eventually leading to cell death and, consequently, loss of vision. Here, we have hypothesized that RP associated with mutations in phosphodiesterase-6 (PDE6) provokes a metabolic aberration in rod cells that promotes the pathological consequences of elevated cGMP and Ca2+, which are induced by the Pde6 mutation. Inhibition of sirtuin 6 (SIRT6), a histone deacetylase repressor of glycolytic flux, reprogrammed rods into perpetual glycolysis, thereby driving the accumulation of biosynthetic intermediates, improving outer segment (OS) length, enhancing photoreceptor survival, and preserving vision. In mouse retinae lacking Sirt6, effectors of glycolytic flux were dramatically increased, leading to upregulation of key intermediates in glycolysis, TCA cycle, and glutaminolysis. Both transgenic and AAV2/8 gene therapy-mediated ablation of Sirt6 in rods provided electrophysiological and anatomic rescue of both rod and cone photoreceptors in a preclinical model of RP. Due to the extensive network of downstream effectors of Sirt6, this study motivates further research into the role that these pathways play in retinal degeneration. Because reprogramming metabolism by enhancing glycolysis is not gene specific, this strategy may be applicable to a wide range of neurodegenerative disorders.
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Abstract
Retinitis pigmentosa is the most common form of hereditary retinal degeneration causing blindness. Great progress has been made in the identification of the causative genes. Gene diagnosis will soon become an affordable routine clinical test because of the wide application of next-generation sequencing. Gene-based therapy provides hope for curing the disease. Investigation into the molecular pathways from mutation to rod cell death may reveal targets for developing new treatment. Related progress with existing systematic review is briefly summarized so that readers may find the relevant references for in-depth reading. Future trends in the study of retinitis pigmentosa are also discussed.
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Affiliation(s)
- Qingjiong Zhang
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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23
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Abstract
Over the last few years, huge progress has been made with regard to the understanding of molecular mechanisms underlying the pathogenesis of neurodegenerative diseases of the eye. Such knowledge has led to the development of gene therapy approaches to treat these devastating disorders. Challenges regarding the efficacy and efficiency of therapeutic gene delivery have driven the development of novel therapeutic approaches, which continue to evolve the field of ocular gene therapy. In this review article, we will discuss the evolution of preclinical and clinical strategies that have improved gene therapy in the eye, showing that treatment of vision loss has a bright future.
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Affiliation(s)
- Lolita Petit
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Hemant Khanna
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts.,2 Department of Neurobiology, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Claudio Punzo
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts.,2 Department of Neurobiology, University of Massachusetts Medical School , Worcester, Massachusetts
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24
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Wert KJ, Mahajan VB, Zhang L, Yan Y, Li Y, Tosi J, Hsu CW, Nagasaki T, Janisch KM, Grant MB, Mahajan M, Bassuk AG, Tsang SH. Neuroretinal hypoxic signaling in a new preclinical murine model for proliferative diabetic retinopathy. Signal Transduct Target Ther 2016; 1. [PMID: 27195131 PMCID: PMC4868361 DOI: 10.1038/sigtrans.2016.5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Diabetic retinopathy (DR) affects approximately one-third of diabetic patients and, if left untreated, progresses to proliferative DR (PDR) with associated vitreous hemorrhage, retinal detachment, iris neovascularization, glaucoma and irreversible blindness. In vitreous samples of human patients with PDR, we found elevated levels of hypoxia inducible factor 1 alpha (HIF1α). HIFs are transcription factors that promote hypoxia adaptation and have important functional roles in a wide range of ischemic and inflammatory diseases. To recreate the human PDR phenotype for a preclinical animal model, we generated a mouse with neuroretinal-specific loss of the von Hippel Lindau tumor suppressor protein, a protein that targets HIF1α for ubiquitination. We found that the neuroretinal cells in these mice overexpressed HIF1α and developed severe, irreversible ischemic retinopathy that has features of human PDR. Rapid progression of retinopathy in these mutant mice should facilitate the evaluation of therapeutic agents for ischemic and inflammatory blinding disorders. In addition, this model system can be used to manipulate the modulation of the hypoxia signaling pathways, for the treatment of non-ocular ischemic and inflammatory disorders.
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Affiliation(s)
- Katherine J Wert
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara & Donald Jonas Laboratory of Regenerative Medicine, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA; Institute of Human Nutrition, Columbia University, New York, NY, USA
| | - Vinit B Mahajan
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA; Omics Laboratory, University of Iowa, Iowa City, IA, USA
| | - Lijuan Zhang
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara & Donald Jonas Laboratory of Regenerative Medicine, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Yuanqing Yan
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Yao Li
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara & Donald Jonas Laboratory of Regenerative Medicine, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Joaquin Tosi
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara & Donald Jonas Laboratory of Regenerative Medicine, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Chun Wei Hsu
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara & Donald Jonas Laboratory of Regenerative Medicine, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Takayuki Nagasaki
- Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Kerstin M Janisch
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara & Donald Jonas Laboratory of Regenerative Medicine, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Maria B Grant
- Eugene and Marilyn Glick Eye Institute, Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - MaryAnn Mahajan
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA; Omics Laboratory, University of Iowa, Iowa City, IA, USA
| | | | - Stephen H Tsang
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara & Donald Jonas Laboratory of Regenerative Medicine, Columbia University, New York, NY, USA; Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA; Institute of Human Nutrition, Columbia University, New York, NY, USA; New York Presbyterian Hospital/Columbia University Medical Center, New York, NY, USA; Department of Pathology and Cellular Biology, Columbia University, New York, NY, USA
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25
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Successful arrest of photoreceptor and vision loss expands the therapeutic window of retinal gene therapy to later stages of disease. Proc Natl Acad Sci U S A 2015; 112:E5844-53. [PMID: 26460017 DOI: 10.1073/pnas.1509914112] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal degenerations cause progressive loss of photoreceptor neurons with eventual blindness. Corrective or neuroprotective gene therapies under development could be delivered at a predegeneration stage to prevent the onset of disease, as well as at intermediate-degeneration stages to slow the rate of progression. Most preclinical gene therapy successes to date have been as predegeneration interventions. In many animal models, as well as in human studies, to date, retinal gene therapy administered well after the onset of degeneration was not able to modify the rate of progression even when successfully reversing dysfunction. We evaluated consequences of gene therapy delivered at intermediate stages of disease in a canine model of X-linked retinitis pigmentosa (XLRP) caused by a mutation in the Retinitis Pigmentosa GTPase Regulator (RPGR) gene. Spatiotemporal natural history of disease was defined and therapeutic dose selected based on predegeneration results. Then interventions were timed at earlier and later phases of intermediate-stage disease, and photoreceptor degeneration monitored with noninvasive imaging, electrophysiological function, and visual behavior for more than 2 y. All parameters showed substantial and significant arrest of the progressive time course of disease with treatment, which resulted in long-term improved retinal function and visual behavior compared with control eyes. Histology confirmed that the human RPGR transgene was stably expressed in photoreceptors and associated with improved structural preservation of rods, cones, and ON bipolar cells together with correction of opsin mislocalization. These findings in a clinically relevant large animal model demonstrate the long-term efficacy of RPGR gene augmentation and substantially broaden the therapeutic window for intervention in patients with RPGR-XLRP.
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26
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Veleri S, Lazar CH, Chang B, Sieving PA, Banin E, Swaroop A. Biology and therapy of inherited retinal degenerative disease: insights from mouse models. Dis Model Mech 2015; 8:109-29. [PMID: 25650393 PMCID: PMC4314777 DOI: 10.1242/dmm.017913] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases.
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Affiliation(s)
- Shobi Veleri
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Csilla H Lazar
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano Sciences, Babes-Bolyai-University, Cluj-Napoca, 400271, Romania
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eyal Banin
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Center for Retinal and Macular Degenerations, Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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27
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Koch SF, Tsai YT, Duong JK, Wu WH, Hsu CW, Wu WP, Bonet-Ponce L, Lin CS, Tsang SH. Halting progressive neurodegeneration in advanced retinitis pigmentosa. J Clin Invest 2015; 125:3704-13. [PMID: 26301813 DOI: 10.1172/jci82462] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/13/2015] [Indexed: 01/03/2023] Open
Abstract
Hereditary retinal degenerative diseases, such as retinitis pigmentosa (RP), are characterized by the progressive loss of rod photoreceptors followed by loss of cones. While retinal gene therapy clinical trials demonstrated temporary improvement in visual function, this approach has yet to achieve sustained functional and anatomical rescue after disease onset in patients. The lack of sustained benefit could be due to insufficient transduction efficiency of viral vectors ("too little") and/or because the disease is too advanced ("too late") at the time therapy is initiated. Here, we tested the latter hypothesis and developed a mouse RP model that permits restoration of the mutant gene in all diseased photoreceptor cells, thereby ensuring sufficient transduction efficiency. We then treated mice at early, mid, or late disease stages. At all 3 time points, degeneration was halted and function was rescued for at least 1 year. Not only do our results demonstrate that gene therapy effectively preserves function after the onset of degeneration, our study also demonstrates that there is a broad therapeutic time window. Moreover, these results suggest that RP patients are treatable, despite most being diagnosed after substantial photoreceptor loss, and that gene therapy research must focus on improving transduction efficiency to maximize clinical impact.
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28
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Sujirakul T, Davis R, Erol D, Zhang L, Schillizzi G, Royo-Dujardin L, Shen S, Tsang S. Bilateral Concordance of the Fundus Hyperautofluorescent Ring in Typical Retinitis Pigmentosa Patients. Ophthalmic Genet 2015; 36:113-22. [PMID: 24111858 PMCID: PMC4777350 DOI: 10.3109/13816810.2013.841962] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND It has long been assumed that in retinitis pigmentosa, disease presentation and progression are symmetrical. This study investigated whether hyperautofluorescent ring size, one known marker of disease progression, is symmetrical in typical RP patients. MATERIALS AND METHODS A total of 88 patients with typical retinitis pigmentosa were enrolled in the study. Each presented with a hyperautofluorescent ring when imaged at baseline with fundus autofluorescence (AF). Vertical and horizontal diameters were analyzed according to mode of inheritance and age group. Seven of 88 patients had data missing in one eye and were excluded from further analysis. RESULTS There was no significant relationship between hyperautofluorescent ring diameter and inheritance mode. There was a tendency toward smaller ring size with age and 3.7% of subjects displayed marked asymmetry in ring size between right and left eyes, although their electroretinogram results did not differ. Overall, when patients were considered as a group, there was a high correlation between right and left eyes' horizontal and vertical diameters (r=0.99, p<0.0001; r=0.98, p<0.0001). Comparing individual patients' eyes, and accounting for measurement error, a smaller majority of patients displayed symmetry of the hyperautofluorescent ring in both dimensions (85.7% in the vertical dimension, 87.3% in the horizontal dimension). CONCLUSION This study confirmed the highly symmetrical nature of the hyperautofluorescent ring in RP patients, except in a small subgroup. AF results, which provide less variability per image, and are consistently interpreted between different observers, may be a more sensitive and reliable method for testing symmetry than many functional tests.
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Wert KJ, Bassuk AG, Wu WH, Gakhar L, Coglan D, Mahajan M, Wu S, Yang J, Lin CS, Tsang SH, Mahajan VB. CAPN5 mutation in hereditary uveitis: the R243L mutation increases calpain catalytic activity and triggers intraocular inflammation in a mouse model. Hum Mol Genet 2015; 24:4584-98. [PMID: 25994508 DOI: 10.1093/hmg/ddv189] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 05/18/2015] [Indexed: 12/21/2022] Open
Abstract
A single amino acid mutation near the active site of the CAPN5 protease was linked to the inherited blinding disorder, autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV, OMIM #193235). In homology modeling with other calpains, this R243L CAPN5 mutation was situated in a mobile loop that gates substrate access to the calcium-regulated active site. In in vitro activity assays, the mutation increased calpain protease activity and made it far more active at low concentrations of calcium. To test whether the disease allele could yield an animal model of ADNIV, we created transgenic mice expressing human (h) CAPN5(R243L) only in the retina. The resulting hCAPN5(R243L) transgenic mice developed a phenotype consistent with human uveitis and ADNIV, at the clinical, histological and molecular levels. The fundus of hCAPN5(R243L) mice showed enhanced autofluorescence (AF) and pigment changes indicative of reactive retinal pigment epithelial cells and photoreceptor degeneration. Electroretinography showed mutant mouse eyes had a selective loss of the b-wave indicating an inner-retina signaling defect. Histological analysis of mutant mouse eyes showed protein extravasation from dilated vessels into the anterior chamber and vitreous, vitreous inflammation, vitreous and retinal fibrosis and retinal degeneration. Analysis of gene expression changes in the hCAPN5(R243L) mouse retina showed upregulation of several markers, including members of the Toll-like receptor pathway, chemokines and cytokines, indicative of both an innate and adaptive immune response. Since many forms of uveitis share phenotypic characteristics of ADNIV, this mouse offers a model with therapeutic testing utility for ADNIV and uveitis patients.
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Affiliation(s)
- Katherine J Wert
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine and Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Institute of Human Nutrition, College of Physicians and Surgeons
| | | | - Wen-Hsuan Wu
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine and Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute
| | - Lokesh Gakhar
- Department of Biochemistry, Protein Crystallography Facility
| | - Diana Coglan
- Omics Laboratory and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
| | - MaryAnn Mahajan
- Omics Laboratory and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
| | - Shu Wu
- Department of Pediatrics and Neurology
| | - Jing Yang
- Protein Crystallography Facility, Omics Laboratory and
| | | | - Stephen H Tsang
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine and Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Institute of Human Nutrition, College of Physicians and Surgeons, Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA,
| | - Vinit B Mahajan
- Omics Laboratory and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
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30
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Ben M’Barek K, Regent F, Monville C. Use of human pluripotent stem cells to study and treat retinopathies. World J Stem Cells 2015; 7:596-604. [PMID: 25914766 PMCID: PMC4404394 DOI: 10.4252/wjsc.v7.i3.596] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/13/2014] [Accepted: 12/31/2014] [Indexed: 02/06/2023] Open
Abstract
Human cell types affected by retinal diseases (such as age-related macular degeneration or retinitis pimentosa) are limited in cell number and of reduced accessibility. As a consequence, their isolation for in vitro studies of disease mechanisms or for drug screening efforts is fastidious. Human pluripotent stem cells (hPSCs), either of embryonic origin or through reprogramming of adult somatic cells, represent a new promising way to generate models of human retinopathies, explore the physiopathological mechanisms and develop novel therapeutic strategies. Disease-specific human embryonic stem cells were the first source of material to be used to study certain disease states. The recent demonstration that human somatic cells, such as fibroblasts or blood cells, can be genetically converted to induce pluripotent stem cells together with the continuous improvement of methods to differentiate these cells into disease-affected cellular subtypes opens new perspectives to model and understand a large number of human pathologies, including retinopathies. This review focuses on the added value of hPSCs for the disease modeling of human retinopathies and the study of their molecular pathological mechanisms. We also discuss the recent use of these cells for establishing the validation studies for therapeutic intervention and for the screening of large compound libraries to identify candidate drugs.
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31
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Maria M, Ajmal M, Azam M, Waheed NK, Siddiqui SN, Mustafa B, Ayub H, Ali L, Ahmad S, Micheal S, Hussain A, Shah STA, Ali SHB, Ahmed W, Khan YM, den Hollander AI, Haer-Wigman L, Collin RWJ, Khan MI, Qamar R, Cremers FPM. Homozygosity mapping and targeted sanger sequencing reveal genetic defects underlying inherited retinal disease in families from pakistan. PLoS One 2015; 10:e0119806. [PMID: 25775262 PMCID: PMC4361598 DOI: 10.1371/journal.pone.0119806] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 01/13/2015] [Indexed: 11/18/2022] Open
Abstract
Background Homozygosity mapping has facilitated the identification of the genetic causes underlying inherited diseases, particularly in consanguineous families with multiple affected individuals. This knowledge has also resulted in a mutation dataset that can be used in a cost and time effective manner to screen frequent population-specific genetic variations associated with diseases such as inherited retinal disease (IRD). Methods We genetically screened 13 families from a cohort of 81 Pakistani IRD families diagnosed with Leber congenital amaurosis (LCA), retinitis pigmentosa (RP), congenital stationary night blindness (CSNB), or cone dystrophy (CD). We employed genome-wide single nucleotide polymorphism (SNP) array analysis to identify homozygous regions shared by affected individuals and performed Sanger sequencing of IRD-associated genes located in the sizeable homozygous regions. In addition, based on population specific mutation data we performed targeted Sanger sequencing (TSS) of frequent variants in AIPL1, CEP290, CRB1, GUCY2D, LCA5, RPGRIP1 and TULP1, in probands from 28 LCA families. Results Homozygosity mapping and Sanger sequencing of IRD-associated genes revealed the underlying mutations in 10 families. TSS revealed causative variants in three families. In these 13 families four novel mutations were identified in CNGA1, CNGB1, GUCY2D, and RPGRIP1. Conclusions Homozygosity mapping and TSS revealed the underlying genetic cause in 13 IRD families, which is useful for genetic counseling as well as therapeutic interventions that are likely to become available in the near future.
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Affiliation(s)
- Maleeha Maria
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Muhammad Ajmal
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Maleeha Azam
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nadia Khalida Waheed
- Tufts University Medical School, Boston, Massachusetts, United States of America
| | | | - Bilal Mustafa
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Humaira Ayub
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Liaqat Ali
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Shakeel Ahmad
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Shazia Micheal
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alamdar Hussain
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Syed Tahir Abbas Shah
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
| | - Syeda Hafiza Benish Ali
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan
| | - Waqas Ahmed
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- University of Haripur, Haripur, Pakistan
| | - Yar Muhammad Khan
- Department of Chemistry, University of Science and Technology, Bannu, Pakistan
| | - Anneke I. den Hollander
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Rob W. J. Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Muhammad Imran Khan
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Raheel Qamar
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Al-Nafees Medical College & Hospital, Isra University, Islamabad, Pakistan
| | - Frans P. M. Cremers
- Department of Biosciences, Commission on Science and Technology for Sustainable Development in the South Institute of Information Technology, Islamabad, Pakistan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- * E-mail:
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Chen Y, Tang H. High-throughput screening assays to identify small molecules preventing photoreceptor degeneration caused by the rhodopsin P23H mutation. Methods Mol Biol 2015; 1271:369-90. [PMID: 25697536 DOI: 10.1007/978-1-4939-2330-4_24] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
High-throughput screening (HTS) is one of the major techniques for discovering promising molecules for drug development. Rhodopsin mutations cause the most common autosomal dominant form of retinitis pigmentosa, an inherited retinal degenerative disease that currently has no effective treatment. To find an optimal pharmacological treatment for rhodopsin-associated retinitis pigmentosa, we performed two cell-based HTSs with mammalian cells expressing the P23H rod opsin mutant and identified two sets of novel compounds for further validation and characterization. The first HTS screen identified pharmacological chaperones of P23H opsin that increased its translocation from the endoplasmic reticulum to the plasma membrane. The second HTS screen selected small molecules that enhanced the clearance of the mutant opsin while vision could be sustained by the healthy gene allele expressing wild-type rhodopsin. Here we describe the methodology of these two HTS assays in detail.
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Affiliation(s)
- Yuanyuan Chen
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106-4965, USA,
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Carroll SP, Jørgensen PS, Kinnison MT, Bergstrom CT, Denison RF, Gluckman P, Smith TB, Strauss SY, Tabashnik BE. Applying evolutionary biology to address global challenges. Science 2014; 346:1245993. [PMID: 25213376 PMCID: PMC4245030 DOI: 10.1126/science.1245993] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Two categories of evolutionary challenges result from escalating human impacts on the planet. The first arises from cancers, pathogens, and pests that evolve too quickly and the second, from the inability of many valued species to adapt quickly enough. Applied evolutionary biology provides a suite of strategies to address these global challenges that threaten human health, food security, and biodiversity. This Review highlights both progress and gaps in genetic, developmental, and environmental manipulations across the life sciences that either target the rate and direction of evolution or reduce the mismatch between organisms and human-altered environments. Increased development and application of these underused tools will be vital in meeting current and future targets for sustainable development.
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Affiliation(s)
- Scott P Carroll
- Department of Entomology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA. Institute for Contemporary Evolution, Davis, CA 95616, USA.
| | - Peter Søgaard Jørgensen
- Center for Macroecology, Evolution and Climate, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark. Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, 2100 Copenhagen, Denmark.
| | - Michael T Kinnison
- School of Biology and Ecology, University of Maine, Orono, ME 04469, USA
| | - Carl T Bergstrom
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - R Ford Denison
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Minneapolis, MN 55108, USA
| | - Peter Gluckman
- Centre for Human Evolution, Adaptation and Disease, Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Thomas B Smith
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA. Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, 619 Charles E. Young Drive East, Los Angeles, 90095-1496, CA
| | - Sharon Y Strauss
- Department of Evolution and Ecology and Center for Population Biology, University of California, Davis, One Shields Avenue, CA 95616, USA
| | - Bruce E Tabashnik
- Department of Entomology, University of Arizona, Tucson, AZ 85721, USA
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Nelson NG, Skeie JM, Muradov H, Rowell HA, Seo S, Mahajan VB. CAPN5 gene silencing by short hairpin RNA interference. BMC Res Notes 2014; 7:642. [PMID: 25216694 PMCID: PMC4169796 DOI: 10.1186/1756-0500-7-642] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 09/09/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The purpose of this project was to identify short hairpin RNA (shRNA) sequences that can suppress expression of human CAPN5 in which gain-of-function mutants cause autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV). We created HEK293T cells that stably express an ADNIV disease allele, CAPN5-p.R243L. Transfection protocols were optimized for neuroblastoma SHSY5Y cells. The gene silencing effect of four different shRNA plasmids that target CAPN5 was tested. RNA and protein expression was determined using quantitative RT-PCR and immunoblot analysis. FINDINGS Two of four shRNA plasmids reduced mutant CAPN5 RNA in a stable cell line. Similar knockdown was observed in SH-SY5Y cells that natively express CAPN5. Lactose dehydrogenase assays showed that down-regulation of CAPN5 was not cytotoxic. CONCLUSIONS CAPN5 expression can be suppressed by shRNA-based RNA interference. Further testing in ADNIV models will determine the potential of gene silencing as a strategy to treat, delay, or prevent blindness in ADNIV patients.
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Affiliation(s)
| | | | | | | | | | - Vinit B Mahajan
- Department of Ophthalmology and Visual Sciences, The University of Iowa Hospitals & Clinics, 200 Hawkins Drive, Iowa City, IA 52242, USA.
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Recent advances of stem cell therapy for retinitis pigmentosa. Int J Mol Sci 2014; 15:14456-74. [PMID: 25141102 PMCID: PMC4159862 DOI: 10.3390/ijms150814456] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/24/2014] [Accepted: 08/11/2014] [Indexed: 12/22/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal disorders characterized by progressive loss of photoreceptors and eventually leads to retina degeneration and atrophy. Until now, the exact pathogenesis and etiology of this disease has not been clear, and many approaches for RP therapies have been carried out in animals and in clinical trials. In recent years, stem cell transplantation-based attempts made some progress, especially the transplantation of bone marrow-derived mesenchymal stem cells (BMSCs). This review will provide an overview of stem cell-based treatment of RP and its main problems, to provide evidence for the safety and feasibility for further clinical treatment.
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Tsang SH, Chan L, Tsai YT, Wu WH, Hsu CW, Yang J, Tosi J, Wert KJ, Davis RJ, Mahajan VB. Silencing of tuberin enhances photoreceptor survival and function in a preclinical model of retinitis pigmentosa (an american ophthalmological society thesis). TRANSACTIONS OF THE AMERICAN OPHTHALMOLOGICAL SOCIETY 2014; 112:103-115. [PMID: 25646031 PMCID: PMC4311672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE To assess the functional consequences of silencing of tuberin, an inhibitor of the mTOR signaling pathway, in a preclinical model of retinitis pigmentosa (RP) in order to test the hypothesis that insufficient induction of the protein kinase B (PKB)-regulated tuberin/mTOR self-survival pathway initiates apoptosis. METHODS In an unbiased genome-scale approach, kinase peptide substrate arrays were used to analyze self-survival pathways at the onset of photoreceptor degeneration. The mutant Pde6b(H620Q)/Pde6b(H620Q) at P14 and P18 photoreceptor outer segment (OS) lysates were labeled with P-ATP and hybridized to an array of 1,164 different synthetic peptide substrates. At this stage, OS of Pde6b(H620Q)/Pde6b(H620Q) rods are morphologically normal. In vitro kinase assays and immunohistochemistry were used to validate phosphorylation. Short hairpin RNA (shRNA) gene silencing was used to validate tuberin's role in regulating survival. RESULTS At the onset of degeneration, 162 peptides were differentially phosphorylated. Protein kinases A, G, C (AGC kinases), and B exhibited increased activity in both peptide array and in vitro kinase assays. Immunohistochemical data confirmed altered phosphorylation patterns for phosphoinositide-dependent kinase-1 (PDK1), ribosomal protein S6 (RPS6), and tuberin. Tuberin gene silencing rescued photoreceptors from degeneration. CONCLUSIONS Phosphorylation of tuberin and RPS6 is due to the upregulated activity of PKB. PKB/tuberin cell growth/survival signaling is activated before the onset of degeneration. Substrates of the AGC kinases in the PKB/tuberin pathway are phosphorylated to promote cell survival. Knockdown of tuberin, the inhibitor of the mTOR pathway, increased photoreceptor survival and function in a preclinical model of RP.
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Affiliation(s)
- Stephen H Tsang
- Institute of Human Nutrition, Department of Pathology and Cell Biology and the Department of Ophthalmology, Columbia University, New York, New York
| | - Lawrence Chan
- Department of Ophthalmology, Columbia University, New York, New York
| | - Yi-Ting Tsai
- Department of Ophthalmology, Columbia University, New York, New York
| | - Wen-Hsuan Wu
- Department of Ophthalmology, Columbia University, New York, New York
| | - Chun-Wei Hsu
- Department of Ophthalmology, Columbia University, New York, New York
| | - Jin Yang
- Department of Ophthalmology, Columbia University, New York, New York; and Tianjin Medical University Eye Hospital, Tianjin, China
| | - Joaquin Tosi
- Department of Ophthalmology, Columbia University, New York, New York; and Kresge Eye Institute, Wayne State University, Detroit, Michigan
| | - Katherine J Wert
- Department of Ophthalmology, Columbia University, New York, New York; and Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Richard J Davis
- Department of Ophthalmology, Columbia University, New York, New York; and Neural Stem Cell Institute, Rensselaer, New York
| | - Vinit B Mahajan
- Omics Lab, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa
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Abstract
Significant advances have been made over the last decade or two in the elucidation of the molecular pathogenesis of inherited ocular disorders. In particular, remarkable successes have been achieved in exploration of gene-based medicines for these conditions, both in preclinical and in clinical studies. Progress in the development of gene therapies targeted toward correcting the primary genetic defect or focused on modulating secondary effects associated with retinal pathologies are discussed in the review. Likewise, the recent utilization of genes encoding light-sensing molecules to provide new functions to residual retinal cells in the degenerating retina is discussed. While a great deal has been learned over the last two decades, the next decade should result in an increasing number of preclinical studies progressing to human clinical trial, an exciting prospect for patients, those active in research and development and bystanders alike.
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Li Y, Wu WH, Hsu CW, Nguyen HV, Tsai YT, Chan L, Nagasaki T, Maumenee IH, Yannuzzi LA, Hoang QV, Hua H, Egli D, Tsang SH. Gene therapy in patient-specific stem cell lines and a preclinical model of retinitis pigmentosa with membrane frizzled-related protein defects. Mol Ther 2014; 22:1688-97. [PMID: 24895994 DOI: 10.1038/mt.2014.100] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 05/23/2014] [Indexed: 12/21/2022] Open
Abstract
Defects in Membrane Frizzled-related Protein (MFRP) cause autosomal recessive retinitis pigmentosa (RP). MFRP codes for a retinal pigment epithelium (RPE)-specific membrane receptor of unknown function. In patient-specific induced pluripotent stem (iPS)-derived RPE cells, precise levels of MFRP, and its dicistronic partner CTRP5, are critical to the regulation of actin organization. Overexpression of CTRP5 in naïve human RPE cells phenocopied behavior of MFRP-deficient patient RPE (iPS-RPE) cells. AAV8 (Y733F) vector expressing human MFRP rescued the actin disorganization phenotype and restored apical microvilli in patient-specific iPS-RPE cell lines. As a result, AAV-treated MFRP mutant iPS-RPE recovered pigmentation and transepithelial resistance. The efficacy of AAV-mediated gene therapy was also evaluated in Mfrp(rd6)/Mfrp(rd6) mice--an established preclinical model of RP--and long-term improvement in visual function was observed in AAV-Mfrp-treated mice. This report is the first to indicate the successful use of human iPS-RPE cells as a recipient for gene therapy. The observed favorable response to gene therapy in both patient-specific cell lines, and the Mfrp(rd6)/Mfrp(rd6) preclinical model suggests that this form of degeneration caused by MFRP mutations is a potential target for interventional trials.
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Affiliation(s)
- Yao Li
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA
| | - Wen-Hsuan Wu
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA
| | - Chun-Wei Hsu
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA
| | - Huy V Nguyen
- Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Yi-Ting Tsai
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA
| | - Lawrence Chan
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA
| | - Takayuki Nagasaki
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA
| | - Irene H Maumenee
- Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Lawrence A Yannuzzi
- Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA
| | - Quan V Hoang
- 1] Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine, and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, New York, USA [2] New York-Presbyterian Hospital/Columbia University Medical Center, New York, New York, USA
| | - Haiqing Hua
- 1] Division of Molecular Genetics, Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA [2] New York Stem Cell Foundation, New York, New York, USA
| | - Dieter Egli
- New York Stem Cell Foundation, New York, New York, USA
| | - Stephen H Tsang
- 1] New York-Presbyterian Hospital/Columbia University Medical Center, New York, New York, USA [2] Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
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Wert KJ, Lin JH, Tsang SH. General pathophysiology in retinal degeneration. DEVELOPMENTS IN OPHTHALMOLOGY 2014; 53:33-43. [PMID: 24732759 DOI: 10.1159/000357294] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6β) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade.
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Affiliation(s)
- Katherine J Wert
- Bernard and Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, New York, N.Y., USA
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Wert KJ, Skeie JM, Bassuk AG, Olivier AK, Tsang SH, Mahajan VB. Functional validation of a human CAPN5 exome variant by lentiviral transduction into mouse retina. Hum Mol Genet 2013; 23:2665-77. [PMID: 24381307 DOI: 10.1093/hmg/ddt661] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Exome sequencing indicated that the gene encoding the calpain-5 protease, CAPN5, is the likely cause of retinal degeneration and autoimmune uveitis in human patients with autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV, OMIM #193235). To explore the mechanism of ADNIV, a human CAPN5 disease allele was expressed in mouse retinas with a lentiviral vector created to express either the wild-type human (h) CAPN5 or the ADNIV mutant hCAPN5-R243L allele under a rhodopsin promoter with tandem green fluorescent protein (GFP) expression. Vectors were injected into the subretinal space of perinatal mice. Mouse phenotypes were analyzed using electroretinography, histology and inflammatory gene expression profiling. Mouse calpain-5 showed high homology to its human ortholog with >98% sequence identity that includes the ADNIV mutant residue. Calpain-5 protein was expressed in the inner and outer segments of the photoreceptors and in the outer plexiform layer. Expression of the hCAPN5-R243L allele caused loss of the electroretinogram b-wave, photoreceptor degeneration and induction of immune cell infiltration and inflammatory genes in the retina, recapitulating major features of the ADNIV phenotype. Intraocular neovascularization and fibrosis were not observed during the study period. Our study shows that expression of the hCAPN5-R243L disease allele elicits an ADNIV-like disease in mice. It further suggests that ADNIV is due to CAPN5 gain-of-function rather than haploinsufficiency, and retinal expression may be sufficient to generate an autoimmune response. Genetic models of ADNIV in the mouse can be used to explore protease mechanisms in retinal degeneration and inflammation as well as preclinical therapeutic testing.
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Affiliation(s)
- Katherine J Wert
- Bernard and Shirlee Brown Glaucoma Laboratory, Department of Pathology and Cell Biology, College of Physicians and Surgeons
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Petrs-Silva H, Linden R. Advances in gene therapy technologies to treat retinitis pigmentosa. Clin Ophthalmol 2013; 8:127-36. [PMID: 24391438 PMCID: PMC3878960 DOI: 10.2147/opth.s38041] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Retinitis pigmentosa (RP) is a class of diseases that leads to progressive degeneration of the retina. Experimental approaches to gene therapy for the treatment of inherited retinal dystrophies have advanced in recent years, inclusive of the safe delivery of genes to the human retina. This review is focused on the development of gene therapy for RP using recombinant adenoassociated viral vectors, which show a positive safety record and have so far been successful in several clinical trials for congenital retinal disease. Gene therapy for RP is under development in a variety of animal models, and the results raise expectations of future clinical application. Nonetheless, the translation of such strategies to the bedside requires further understanding of the mutations and mechanisms that cause visual defects, as well as thorough examination of potential adverse effects.
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Affiliation(s)
- Hilda Petrs-Silva
- Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael Linden
- Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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42
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Antoniu S. Fresh from the designation pipeline: orphan drugs recently designated in the European Union (June – August 2013). Expert Opin Orphan Drugs 2013. [DOI: 10.1517/21678707.2013.857597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
The third-most common cause of autosomal recessive retinitis pigmentosa (RP) is due to defective cGMP phosphodiesterase-6 (PDE6). Previous work using viral gene therapy on PDE6-mutant mouse models demonstrated photoreceptors can be rescued if administered before degeneration. However, whether visual function can be rescued after degeneration onset has not been addressed. This is a clinically important question, as newly diagnosed patients exhibit considerable loss of rods and cones in their peripheral retinas. We have generated and characterized a tamoxifen inducible Cre-loxP rescue allele, Pde6b(Stop), which allows us to temporally correct PDE6-deficiency. Whereas untreated mutants exhibit degeneration, activation of Cre-loxP recombination in early embryogenesis produced stable long-term rescue. Reversal at later time-points showed partial long-term or short-lived rescue. Our results suggest stable restoration of retinal function by gene therapy can be achieved if a sufficient number of rods are treated. Because patients are generally diagnosed after extensive loss of rods, the success of clinical trials may depend on identifying patients as early as possible to maximize the number of treatable rods.
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Wert KJ, Sancho-Pelluz J, Tsang SH. Mid-stage intervention achieves similar efficacy as conventional early-stage treatment using gene therapy in a pre-clinical model of retinitis pigmentosa. Hum Mol Genet 2013; 23:514-23. [PMID: 24101599 DOI: 10.1093/hmg/ddt452] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Deficiencies in rod-specific cyclic guanosine monophosphate (cGMP) phosphodiesterase-6 (PDE6) are the third most common cause of autosomal recessive retinitis pigmentosa (RP). Previously, viral gene therapy approaches on pre-clinical models with mutations in PDE6 have demonstrated that the photoreceptor cell survival and visual function can be rescued when the gene therapy virus is delivered into the subretinal space before the onset of disease. However, no studies have currently been published that analyze rescue effects after disease onset, a time when human RP patients are diagnosed by a clinician and would receive the treatment. We utilized the AAV2/8(Y733F)-Rho-Pde6α gene therapy virus and injected it into a pre-clinical model of RP with a mutation within the alpha subunit of PDE6: Pde6α(D670G). These mice were previously shown to have long-term photoreceptor cell rescue when this gene therapy virus was delivered before the onset of disease. Now, we have determined that subretinal transduction of this rod-specific transgene at post-natal day (P) 21, when approximately half of the photoreceptor cells have undergone degeneration, is more efficient in rescuing cone than rod photoreceptor function long term. Therefore, AAV2/8(Y733F)-Rho-Pde6α is an effective gene therapy treatment that can be utilized in the clinical setting, in human patients who have lost portions of their peripheral visual field and are in the mid-stage of disease when they first present to an eye-care professional.
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Affiliation(s)
- Katherine J Wert
- Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology
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