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McDonald A, Wijnholds J. Retinal Ciliopathies and Potential Gene Therapies: A Focus on Human iPSC-Derived Organoid Models. Int J Mol Sci 2024; 25:2887. [PMID: 38474133 DOI: 10.3390/ijms25052887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
The human photoreceptor function is dependent on a highly specialised cilium. Perturbation of cilial function can often lead to death of the photoreceptor and loss of vision. Retinal ciliopathies are a genetically diverse range of inherited retinal disorders affecting aspects of the photoreceptor cilium. Despite advances in the understanding of retinal ciliopathies utilising animal disease models, they can often lack the ability to accurately mimic the observed patient phenotype, possibly due to structural and functional deviations from the human retina. Human-induced pluripotent stem cells (hiPSCs) can be utilised to generate an alternative disease model, the 3D retinal organoid, which contains all major retinal cell types including photoreceptors complete with cilial structures. These retinal organoids facilitate the study of disease mechanisms and potential therapies in a human-derived system. Three-dimensional retinal organoids are still a developing technology, and despite impressive progress, several limitations remain. This review will discuss the state of hiPSC-derived retinal organoid technology for accurately modelling prominent retinal ciliopathies related to genes, including RPGR, CEP290, MYO7A, and USH2A. Additionally, we will discuss the development of novel gene therapy approaches targeting retinal ciliopathies, including the delivery of large genes and gene-editing techniques.
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Affiliation(s)
- Andrew McDonald
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
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Menger KE, Logan A, Luhmann UF, Smith AJ, Wright AF, Ali RR, Murphy MP. In vivo measurement of mitochondrial ROS production in mouse models of photoreceptor degeneration. Redox Biochem Chem 2023; 5-6:None. [PMID: 38046619 PMCID: PMC10686909 DOI: 10.1016/j.rbc.2023.100007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/18/2023] [Accepted: 07/24/2023] [Indexed: 12/05/2023]
Abstract
Retinitis pigmentosa (RP) is a disease characterised by photoreceptor cell death. It can be initiated by mutations in a number of different genes, primarily affecting rods, which will die first, resulting in loss of night vision. The secondary death of cones then leads to loss of visual acuity and blindness. We set out to investigate whether increased mitochondrial reactive oxygen species (ROS) formation, plays a role in this sequential photoreceptor degeneration. To do this we measured mitochondrial H2O2 production within mouse eyes in vivo using the mass spectrometric probe MitoB. We found higher levels of mitochondrial ROS that preceded photoreceptor loss in four mouse models of RP: Pde6brd1/rd1; Prhp2rds/rds; RPGR-/-; Cln6nclf. In contrast, there was no increase in mitochondrial ROS in loss of function models of vision loss (GNAT-/-, OGC), or where vision loss was not due to photoreceptor death (Cln3). Upregulation of Nrf2 transcriptional activity with dimethylfumarate (DMF) lowered mitochondrial ROS in RPGR-/- mice. These findings have important implications for the mechanism and treatment of RP.
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Affiliation(s)
- Katja E. Menger
- UCL Institute of Ophthalmology, Bath St, London, EC1V 9EL, UK
| | - Angela Logan
- MRC-Mitochondrial Biology Unit, The Keith Peters Building, University of Cambridge, Cambridge, CB2 0XY, UK
| | | | | | - Alan F. Wright
- MRC Human Genetics Unit, Western General Hospital, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Robin R. Ali
- UCL Institute of Ophthalmology, Bath St, London, EC1V 9EL, UK
| | - Michael P. Murphy
- MRC-Mitochondrial Biology Unit, The Keith Peters Building, University of Cambridge, Cambridge, CB2 0XY, UK
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Han RC, Taylor LJ, Martinez-Fernandez de la Camara C, Henderson RH, Thompson DA, Cehajic-Kapetanovic J, MacLaren RE. Is RPGR-related retinal dystrophy associated with systemic disease? A case series. Ophthalmic Genet 2023; 44:577-584. [PMID: 36602268 DOI: 10.1080/13816810.2022.2163405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/30/2022] [Accepted: 12/23/2022] [Indexed: 01/06/2023]
Abstract
BACKGROUND Ciliopathies responsible for retinitis pigmentosa can also cause systemic manifestations. RPGR is a ciliary gene and pathogenic variants in RPGR cause a retinal ciliopathy, the commonest cause of X-linked recessive retinitis pigmentosa. The RPGR protein interacts with numerous other ciliary proteins present in the transition zone of both motile and sensory cilia, and may play an important role in regulating ciliary protein transport. There has been a growing, putative association of RPGR variants with systemic ciliopathies: mainly sino-respiratory infections and primary ciliary dyskinesia. MATERIALS AND METHODS Retrospective case series of patients with RPGR-RP presenting to Oxford Eye Hospital with systemic disease. RESULTS We report three children with RPGR-related rod-cone dystrophy, all of whom have mutations in the N-terminus of RPGR. Two cases co-presented with confirmed diagnoses of primary ciliary dyskinesia and one case with multiple sino-respiratory symptoms strongly suggestive of primary ciliary dyskinesia. These and all previously reported RPGR co-pathologies relate to ciliopathies and have no other systemic associations. CONCLUSIONS The link between RPGR variants and a systemic ciliopathy remains plausible, but currently unproven.
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Affiliation(s)
- Ruofan Connie Han
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Laura J Taylor
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Robert H Henderson
- Department of Ophthalmology, Great Ormond Street Children's Hospital, London, UK
| | - Dorothy A Thompson
- Department of Ophthalmology, Great Ormond Street Children's Hospital, London, UK
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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Awadh Hashem S, Georgiou M, Ali RR, Michaelides M. RPGR-Related Retinopathy: Clinical Features, Molecular Genetics, and Gene Replacement Therapy. Cold Spring Harb Perspect Med 2023; 13:a041280. [PMID: 37188525 PMCID: PMC10626266 DOI: 10.1101/cshperspect.a041280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Retinitis pigmentosa GTPase regulator (RPGR) gene variants are the predominant cause of X-linked retinitis pigmentosa (XLRP) and a common cause of cone-rod dystrophy (CORD). XLRP presents as early as the first decade of life, with impaired night vision and constriction of peripheral visual field and rapid progression, eventually leading to blindness. In this review, we present RPGR gene structure and function, molecular genetics, animal models, RPGR-associated phenotypes and highlight emerging potential treatments such as gene-replacement therapy.
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Affiliation(s)
- Shaima Awadh Hashem
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, United Kingdom
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, United Kingdom
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Robin R Ali
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, United Kingdom
- Centre for Cell and Gene Therapy, King's College London, London WC2R 2LS, United Kingdom
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, United Kingdom
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Masek M, Bachmann-Gagescu R. Control of protein and lipid composition of photoreceptor outer segments-Implications for retinal disease. Curr Top Dev Biol 2023; 155:165-225. [PMID: 38043951 DOI: 10.1016/bs.ctdb.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Vision is arguably our most important sense, and its loss brings substantial limitations to daily life for affected individuals. Light is perceived in retinal photoreceptors (PRs), which are highly specialized neurons subdivided into several compartments with distinct functions. The outer segments (OSs) of photoreceptors represent highly specialized primary ciliary compartments hosting the phototransduction cascade, which transforms incoming light into a neuronal signal. Retinal disease can result from various pathomechanisms originating in distinct subcompartments of the PR cell, or in the retinal pigment epithelium which supports the PRs. Dysfunction of primary cilia causes human disorders known as "ciliopathies", in which retinal disease is a common feature. This chapter focuses on PR OSs, discussing the mechanisms controlling their complex structure and composition. A sequence of tightly regulated sorting and trafficking events, both upstream of and within this ciliary compartment, ensures the establishment and maintenance of the adequate proteome and lipidome required for signaling in response to light. We discuss in particular our current understanding of the role of ciliopathy proteins involved in multi-protein complexes at the ciliary transition zone (CC2D2A) or BBSome (BBS1) and how their dysfunction causes retinal disease. While the loss of CC2D2A prevents the fusion of vesicles and delivery of the photopigment rhodopsin to the ciliary base, leading to early OS ultrastructural defects, BBS1 deficiency results in precocious accumulation of cholesterol in mutant OSs and decreased visual function preceding morphological changes. These distinct pathomechanisms underscore the central role of ciliary proteins involved in multiple processes controlling OS protein and lipid composition.
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Affiliation(s)
- Markus Masek
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland; Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Ruxandra Bachmann-Gagescu
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland; Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland; University Research Priority Program AdaBD, University of Zurich, Zurich, Switzerland.
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Kelley RA, Wu Z. Utilization of the retinal organoid model to evaluate the feasibility of genetic strategies to ameliorate retinal disease(s). Vision Res 2023; 210:108269. [PMID: 37295270 DOI: 10.1016/j.visres.2023.108269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
Organoid models have quickly become a popular research tool to evaluate novel therapeutics on 3-D recapitulated tissue. This has enabled researchers to use physiologically relevant human tissue in vitro to augment the standard use of immortalized cells and animal models. Organoids can also provide a model when an engineered animal cannot recreate a specific disease phenotype. In particular, the retinal research field has taken advantage of this burgeoning technology to provide insight into inherited retinal disease(s) mechanisms and therapeutic intervention to ameliorate their effects. In this review we will discuss the use of both wild-type and patient-specific retinal organoids to further gene therapy research that could potentially prevent retinal disease(s) progression. Furthermore, we will discuss the pitfalls of current retinal organoid technology and present potential solutions that could overcome these hurdles in the near future.
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Affiliation(s)
- Ryan A Kelley
- PTC Therapeutics, 100 Corporate Ct #2400, South Plainfield, NJ 07080, USA.
| | - Zhijian Wu
- PTC Therapeutics, 100 Corporate Ct #2400, South Plainfield, NJ 07080, USA
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Yamoah A, Tripathi P, Guo H, Scheve L, Walter P, Johnen S, Müller F, Weis J, Goswami A. Early Alterations of RNA Binding Protein (RBP) Homeostasis and ER Stress-Mediated Autophagy Contributes to Progressive Retinal Degeneration in the rd10 Mouse Model of Retinitis Pigmentosa (RP). Cells 2023; 12:cells12071094. [PMID: 37048167 PMCID: PMC10092976 DOI: 10.3390/cells12071094] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 04/14/2023] Open
Abstract
The retinal degeneration 10 (rd10) mouse model is widely used to study retinitis pigmentosa (RP) pathomechanisms. It offers a rather unique opportunity to study trans-neuronal degeneration because the cell populations in question are separated anatomically and the mutated Pde6b gene is selectively expressed in rod photoreceptors. We hypothesized that RNA binding protein (RBP) aggregation and abnormal autophagy might serve as early pathogenic events, damaging non-photoreceptor retinal cell types that are not primarily targeted by the Pde6b gene defect. We used a combination of immunohistochemistry (DAB, immunofluorescence), electron microscopy (EM), subcellular fractionation, and Western blot analysis on the retinal preparations obtained from both rd10 and wild-type mice. We found early, robust increases in levels of the protective endoplasmic reticulum (ER) calcium (Ca2+) buffering chaperone Sigma receptor 1 (SigR1) together with other ER-Ca2+ buffering proteins in both photoreceptors and non-photoreceptor neuronal cells before any noticeable photoreceptor degeneration. In line with this, we found markedly altered expression of the autophagy proteins p62 and LC3, together with abnormal ER widening and large autophagic vacuoles as detected by EM. Interestingly, these changes were accompanied by early, prominent cytoplasmic and nuclear aggregation of the key RBPs including pTDP-43 and FET family RBPs and stress granule formation. We conclude that progressive neurodegeneration in the rd10 mouse retina is associated with early disturbances of proteostasis and autophagy, along with abnormal cytoplasmic RBP aggregation.
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Affiliation(s)
- Alfred Yamoah
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
- EURON-European Graduate School of Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Priyanka Tripathi
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
- EURON-European Graduate School of Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Haihong Guo
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Leonie Scheve
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Peter Walter
- Department of Ophthalmology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Sandra Johnen
- Department of Ophthalmology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Frank Müller
- Institute of Biological Information Processing, Molecular and Cellular Physiology, IBI-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Joachim Weis
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Anand Goswami
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
- Department of Neurology, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
- Department of Neurology, Eleanor and Lou Gehrig ALS Center, Columbia University, New York, NY 10032, USA
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von Krusenstiern L, Liu J, Liao E, Gow JA, Chen G, Ong T, Lotery AJ, Jalil A, Lam BL, MacLaren RE. Changes in Retinal Sensitivity Associated With Cotoretigene Toliparvovec in X-Linked Retinitis Pigmentosa With RPGR Gene Variations. JAMA Ophthalmol 2023; 141:275-283. [PMID: 36757689 PMCID: PMC9912164 DOI: 10.1001/jamaophthalmol.2022.6254] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 12/13/2022] [Indexed: 02/10/2023]
Abstract
Importance X-linked retinitis pigmentosa (XLRP) is a severe cause of early-onset RP in male individuals, characterized by degeneration of photoreceptors, an extinguished electroretinogram, and vision loss. Objective To assess the duration of improvements in retinal sensitivity associated with a single, subretinal injection of cotoretigene toliparvovec (BIIB112/AAV8-RPGR) gene therapy after vitrectomy surgery in the dosed eye over 12 months in part 1 of the Clinical Trial of Retinal Gene Therapy for X-linked Retinitis Pigmentosa Using BIIB112 (XIRIUS) study, compared with untreated fellow eyes and eyes from the untreated subgroup from the Natural History of the Progression of X-Linked Retinitis Pigmentosa (XOLARIS) study. Design, Setting, and Participants This was a post hoc analysis of the XIRIUS and XOLARIS studies. Part 1 of the XIRIUS study was a phase 1, dose-escalation study of 18 male participants 18 years or older enrolled between March 8, 2017, and October 16, 2018, with genetically confirmed RPGR-variant XLRP with active disease and best-corrected visual acuity better than or equal to light perception (cohort 1), 34 to 73 letters (20/40 to 20/200 Snellen equivalent; cohorts 2-3), or greater than or equal to 34 letters (better than or equal to 20/200 Snellen equivalent; cohorts 4-6). Participants from the noninterventional, multicenter, global, prospective XOLARIS clinical study who met the inclusion and exclusion criteria of part 1 of XIRIUS were included as a comparator group (n = 103). Safety assessments included all XIRIUS participants; post hoc associations of retinal sensitivity assessments in XIRIUS only included the 12 participants receiving the 4 highest doses of cotoretigene toliparvovec. Data were analyzed on June 30, 2021. Main Outcomes and Measures Incidence of dose-limiting toxicities (DLTs), treatment-emergent adverse events, changes from baseline in retinal sensitivity (as assessed by macular integrity assessment microperimetry), retinal sensitivity response (achievement of ≥7-dB improvement from baseline at ≥5 of 16 central loci), and low-luminance visual acuity were assessed over 24 months. Results A total of 18 participants (mean [SD] age, 31.9 [9.4] years; male, 100%) were enrolled and completed the XIRIUS study. A subgroup of 103 participants (mean [SD] age, 30.8 [11.4] years; male, 100%) from the XOLARIS study was included. Administration of the 4 highest doses of cotoretigene toliparvovec (n = 12) among the 18 XIRIUS participants was associated with early improvements in retinal sensitivity. One of 103 untreated participants (1%) in the XOLARIS subgroup achieved improved retinal sensitivity at month 12. No DLTs were noted at any dose, and serious adverse events of reduced visual acuity (n = 2) and noninfective retinitis (n = 1) occurred. Conclusions and Relevance Results suggest that early and sustained improvements in retinal sensitivity and low-luminance visual acuity in some participants through 12 months support consideration of additional clinical trials. Trial Registration ClinicalTrials.gov Identifier: XIRIUS: NCT03116113; XOLARIS: NCT04926129.
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Affiliation(s)
| | - Jiajun Liu
- Biogen, Cambridge, Massachusetts
- Now at Kallyope, New York, New York
| | - Eileen Liao
- Biogen, Cambridge, Massachusetts
- Now at Moderna, Cambridge, Massachusetts
| | | | - Guo Chen
- Biogen, Cambridge, Massachusetts
- Now at Beam Therapeutics, Cambridge, Massachusetts
| | - Tuyen Ong
- Biogen, Cambridge, Massachusetts
- Now at Ring Therapeutics, Cambridge, Massachusetts
| | - Andrew J. Lotery
- Clinical Neurosciences Research Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- University Hospital NHS Foundation, Southampton, United Kingdom
| | - Assad Jalil
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | | | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, NIHR Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
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Tebbe L, Mwoyosvi ML, Crane R, Makia MS, Kakakhel M, Cosgrove D, Al-Ubaidi MR, Naash MI. The usherin mutation c.2299delG leads to its mislocalization and disrupts interactions with whirlin and VLGR1. Nat Commun 2023; 14:972. [PMID: 36810733 PMCID: PMC9944904 DOI: 10.1038/s41467-023-36431-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 02/01/2023] [Indexed: 02/24/2023] Open
Abstract
Usher syndrome (USH) is the leading cause of combined deafness-blindness with type 2 A (USH2A) being the most common form. Knockout models of USH proteins, like the Ush2a-/- model that develops a late-onset retinal phenotype, failed to mimic the retinal phenotype observed in patients. Since patient's mutations result in the expression of a mutant protein and to determine the mechanism of USH2A, we generated and evaluated an usherin (USH2A) knock-in mouse expressing the common human disease-mutation, c.2299delG. This mouse exhibits retinal degeneration and expresses a truncated, glycosylated protein which is mislocalized to the photoreceptor inner segment. The degeneration is associated with a decline in retinal function, structural abnormalities in connecting cilium and outer segment and mislocaliztion of the usherin interactors very long G-protein receptor 1 and whirlin. The onset of symptoms is significantly earlier compared to Ush2a-/-, proving expression of mutated protein is required to recapitulate the patients' retinal phenotype.
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Affiliation(s)
- Lars Tebbe
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Maggie L Mwoyosvi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Ryan Crane
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Mustafa S Makia
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Mashal Kakakhel
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | | | - Muayyad R Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
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Hadalin V, Buscarino M, Sajovic J, Meglič A, Jarc-Vidmar M, Hawlina M, Volk M, Fakin A. Genetic Characteristics and Long-Term Follow-Up of Slovenian Patients with RPGR Retinal Dystrophy. Int J Mol Sci 2023; 24:ijms24043840. [PMID: 36835250 PMCID: PMC9958649 DOI: 10.3390/ijms24043840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Genetic characteristics and a long-term clinical follow-up of 18 Slovenian retinitis pigmentosa GTPase regulator (RPGR) patients from 10 families with retinitis pigmentosa (RP) or cone/cone-rod dystrophy (COD/CORD) are reported. RP (eight families) was associated with two already known (p.(Ser407Ilefs*46) and p.(Glu746Argfs*23)) and five novel variants (c.1245+704_1415-2286del, p.(Glu660*), p.(Ala153Thr), c.1506+1G>T, and p.(Arg780Serfs*54)). COD (two families) was associated with p.(Ter1153Lysext*38). The median age of onset in males with RP (N = 9) was 6 years. At the first examination (median age of 32 years), the median best corrected visual acuity (BCVA) was 0.30 logMAR, and all patients had a hyperautofluorescent ring on fundus autofluorescence (FAF) encircling preserved photoreceptors. At the last follow-up (median age of 39 years), the median BCVA was 0.48 logMAR, and FAF showed ring constriction transitioning to patch in 2/9. Among females (N = 6; median age of 40 years), two had normal/near-normal FAF, one had unilateral RP (male pattern), and three had a radial and/or focal pattern of retinal degeneration. After a median of 4 years (4-21) of follow-up, 2/6 exhibited disease progression. The median age of onset in males with COD was 25 years. At first examination (median age of 35 years), the median BCVA was 1.00 logMAR, and all patients had a hyperautofluorescent FAF ring encircling foveal photoreceptor loss. At the last follow-up (median age of 42 years), the median BCVA was 1.30 logMAR, and FAF showed ring enlargement. The majority of the identified variants (75%; 6/8) had not been previously reported in other RPGR cohorts, which suggested the presence of distinct RPGR alleles in the Slovenian population.
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Affiliation(s)
- Vlasta Hadalin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Maša Buscarino
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Andrej Meglič
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Marija Volk
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, Šlajmerjeva 4, 1000 Ljubljana, Slovenia
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
- Correspondence:
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Travor MD. Preclinical Models of Retinitis Pigmentosa. Methods Mol Biol 2023; 2560:181-215. [PMID: 36481897 DOI: 10.1007/978-1-0716-2651-1_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is the name for a group of phenotypically-related heritable retinal degenerative disorders. Many genes have been implicated as causing variants of RP, and while the clinical phenotypes are remarkably similar, they may differ in age of onset, progression, and severity. Common inheritance patterns for specific genes connected with the development of the disorder include autosomal dominant, autosomal recessive, and X-linked. Modeling the disease in animals and other preclinical systems offers a cost-conscious, ethical, and time-efficient method for studying the disease subtypes. The history of RP models is briefly examined, and both naturally occurring and transgenic preclinical models of RP in many different organisms are discussed. Syndromic forms of RP and models thereof are reviewed as well.
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12
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Park K, Leroux MR. Composition, organization and mechanisms of the transition zone, a gate for the cilium. EMBO Rep 2022; 23:e55420. [PMID: 36408840 PMCID: PMC9724682 DOI: 10.15252/embr.202255420] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/08/2022] [Accepted: 10/31/2022] [Indexed: 11/22/2022] Open
Abstract
The cilium evolved to provide the ancestral eukaryote with the ability to move and sense its environment. Acquiring these functions required the compartmentalization of a dynein-based motility apparatus and signaling proteins within a discrete subcellular organelle contiguous with the cytosol. Here, we explore the potential molecular mechanisms for how the proximal-most region of the cilium, termed transition zone (TZ), acts as a diffusion barrier for both membrane and soluble proteins and helps to ensure ciliary autonomy and homeostasis. These include a unique complement and spatial organization of proteins that span from the microtubule-based axoneme to the ciliary membrane; a protein picket fence; a specialized lipid microdomain; differential membrane curvature and thickness; and lastly, a size-selective molecular sieve. In addition, the TZ must be permissive for, and functionally integrates with, ciliary trafficking systems (including intraflagellar transport) that cross the barrier and make the ciliary compartment dynamic. The quest to understand the TZ continues and promises to not only illuminate essential aspects of human cell signaling, physiology, and development, but also to unravel how TZ dysfunction contributes to ciliopathies that affect multiple organ systems, including eyes, kidney, and brain.
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Affiliation(s)
- Kwangjin Park
- Department of Molecular Biology and BiochemistrySimon Fraser UniversityBurnabyBCCanada
- Centre for Cell Biology, Development, and DiseaseSimon Fraser UniversityBurnabyBCCanada
- Present address:
Terry Fox LaboratoryBC CancerVancouverBCCanada
- Present address:
Department of Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | - Michel R Leroux
- Department of Molecular Biology and BiochemistrySimon Fraser UniversityBurnabyBCCanada
- Centre for Cell Biology, Development, and DiseaseSimon Fraser UniversityBurnabyBCCanada
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Martinez-Fernandez de la Camara C, Cehajic-Kapetanovic J, MacLaren RE. Emerging gene therapy products for RPGR-associated X-linked retinitis pigmentosa. Expert Opin Emerg Drugs 2022; 27:431-443. [PMID: 36562395 DOI: 10.1080/14728214.2022.2152003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Mutations in the RPGR gene are responsible for one of the most prevalent and severe types of retinitis pigmentosa. Gene therapy has shown great promise to treat inherited retinal diseases, and currently, four RPGR gene therapy vectors are being evaluated in clinical trials. AREAS COVERED This manuscript reviews the gene therapy products that are in development for X-linked retinitis pigmentosa caused by mutations in RPGR, and the challenges that scientists and clinicians have faced. EXPERT OPINION The development of a gene therapy product for RPGR-associated retinal degeneration has been a great challenge due to the incomplete understanding of the underlying genetics and mechanism of action of RPGR, and on the other hand, due to the instability of the RPGR gene. Three of the four gene therapy vectors currently in clinical trials include a codon-optimized version of the human RPGR sequence, and the other vector contains a shortened version of the human RPGR. To date, the only Phase I/II results published in a peer-reviewed journal demonstrate a good safety profile and an improvement in the visual field using a codon optimized version of RPGRORF15.
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Affiliation(s)
- Cristina Martinez-Fernandez de la Camara
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
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Abstract
The most common inherited eye disease is retinitis pigmentosa (RP). X-linked RP (XLRP) is one of the most severe types of RP, with a considerable disease burden. Patients with XLRP experience a decrease in their vision and become blind in their 4th decade of life, causing much morbidity after starting a rather normal life. Treatment of XLRP remains challenging, and current treatments are not effective enough in restoring vision. Gene therapy of XLRP, capable of restoring the functional RPGR gene, showed promising results in preclinical studies and clinical trials; however, to date, no approved product has entered the market. The development of a gene therapy product needs through preliminary assessment of the drug in animal models before administration to humans. In this article, we reviewed the genetic pathology of XLRP, along with the preclinical aspects of the XLRP gene therapy, animal models, associated assessments, and future challenges and directions.
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Affiliation(s)
- Vahid Mansouri
- Gene Therapy Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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15
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Nassisi M, De Bartolo G, Mohand-Said S, Condroyer C, Antonio A, Lancelot ME, Bujakowska K, Smirnov V, Pugliese T, Neidhardt J, Sahel JA, Zeitz C, Audo I. Retrospective Natural History Study of RPGR-Related Cone- and Cone-Rod Dystrophies While Expanding the Mutation Spectrum of the Disease. Int J Mol Sci 2022; 23:7189. [PMID: 35806195 PMCID: PMC9266815 DOI: 10.3390/ijms23137189] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 06/24/2022] [Accepted: 06/24/2022] [Indexed: 01/06/2023] Open
Abstract
Variants in the X-linked retinitis pigmentosa GTPase regulator gene (RPGR) and, specifically, in its retinal opening reading frame-15 isoform (RPGRORF15) may cause rod-cone (RCD), cone, and cone-rod dystrophies (CDs and CRDs). While RPGR-related RCDs have been frequently evaluated, the characteristics and progression of RPGR-related CD/CRDs are largely unknown. Therefore, the goal of our work was to perform genotype-phenotype correlations specifically in RPGRORF15-related CD/CRDs. This retrospective longitudinal study included 34 index patients and two affected relatives with a molecular diagnosis of RPGR-related CD/CRDs. Patients were recruited at the "Quinze-Vingts" Hospital, Paris, France and screened for mutations in RPGRORF15 at the Institut de la Vision, Paris, France. We identified 29 distinct variants, of which 27 were truncating. All were located in the 3' half of the RPGRORF15 transcript. Twenty of them were novel. Fifteen subjects were affected by CD, the remaining had CRD. When analyzing the longitudinal data, a progressive decline in visual acuity (VA) was noted, with more than 60% of the patients reaching VA ≥ 1 LogMar in the best eye after the fifth decade of life. To our knowledge, this is the largest described study of a cohort of CD/CRD patients affected by RPGRORF15 variants. Longitudinal data showed a rapidly progressive disease, possibly locating an optimal window of intervention for future therapies in younger ages.
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Affiliation(s)
- Marco Nassisi
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, 75012 Paris, France
- Department of Clinical Sciences and Community Health, University of Milan, 20122 Milan, Italy
- Ophthalmology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, 20122 Milan, Italy
| | - Giuseppe De Bartolo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, 75012 Paris, France
| | - Saddek Mohand-Said
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, 75012 Paris, France
| | - Christel Condroyer
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
| | - Aline Antonio
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, 75012 Paris, France
| | - Marie-Elise Lancelot
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
| | - Kinga Bujakowska
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Vasily Smirnov
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Exploration de la Vision et Neuro-Ophthalmologie, Centre Hospitalier Universitaire de Lille, 59000 Lille, France
- Faculté de Médecine, Université de Lille, 59000 Lille, France
| | - Thomas Pugliese
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, 75012 Paris, France
| | - John Neidhardt
- Human Genetics, Faculty VI, School of Medicine and Health Sciences, University of Oldenburg, 26129 Oldenburg, Germany;
- Research Center Neurosensory Science, University Oldenburg, 26129 Oldenburg, Germany
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, 75012 Paris, France
- Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, PA 15213, USA
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (M.N.); (G.D.B.); (S.M.-S.); (C.C.); (A.A.); (M.-E.L.); (K.B.); (V.S.); (T.P.); (J.-A.S.)
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, 75012 Paris, France
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16
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Chahine Karam F, Loi TH, Ma A, Nash BM, Grigg JR, Parekh D, Riley LG, Farnsworth E, Bennetts B, Gonzalez-Cordero A, Jamieson RV. Human iPSC-Derived Retinal Organoids and Retinal Pigment Epithelium for Novel Intronic RPGR Variant Assessment for Therapy Suitability. J Pers Med 2022; 12:jpm12030502. [PMID: 35330501 PMCID: PMC8951517 DOI: 10.3390/jpm12030502] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 02/04/2023] Open
Abstract
The RPGR gene encodes Retinitis Pigmentosa GTPase Regulator, a known interactor with ciliary proteins, which is involved in maintaining healthy photoreceptor cells. Variants in RPGR are the main contributor to X-linked rod-cone dystrophy (RCD), and RPGR gene therapy approaches are in clinical trials. Hence, elucidation of the pathogenicity of novel RPGR variants is important for a patient therapy opportunity. Here, we describe a novel intronic RPGR variant, c.1415 − 9A>G, in a patient with RCD, which was classified as a variant of uncertain significance according to current clinical diagnostic criteria. The variant lay several base pairs intronic to the canonical splice acceptor site, raising suspicion of an RPGR RNA splicing abnormality and consequent protein dysfunction. To investigate disease causation in an appropriate disease model, induced pluripotent stem cells were generated from patient fibroblasts and differentiated to retinal pigment epithelium (iPSC-RPE) and retinal organoids (iPSC-RO). Abnormal RNA splicing of RPGR was demonstrated in patient fibroblasts, iPSC-RPE and iPSC-ROs, leading to a predicted frameshift and premature stop codon. Decreased RPGR expression was demonstrated in these cell types, with a striking loss of RPGR localization at the ciliary transitional zone, critically in the photoreceptor cilium of the patient iPSC-ROs. Mislocalisation of rhodopsin staining was present in the patient’s iPSC-RO rod photoreceptor cells, along with an abnormality of L/M opsin staining affecting cone photoreceptor cells and increased photoreceptor apoptosis. Additionally, patient iPSC-ROs displayed an increase in F-actin expression that was consistent with an abnormal actin regulation phenotype. Collectively, these studies indicate that the splicing abnormality caused by the c.1415 − 9A>G variant has an impact on RPGR function. This work has enabled the reclassification of this variant to pathogenic, allowing the consideration of patients with this variant having access to gene therapy clinical trials. In addition, we have identified biomarkers of disease suitable for the interrogation of other RPGR variants of uncertain significance.
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Affiliation(s)
- Fidelle Chahine Karam
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
| | - To Ha Loi
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
| | - Alan Ma
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Department of Clinical Genetics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
| | - Benjamin M. Nash
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Sydney Genome Diagnostics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
| | - John R. Grigg
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Specialty of Ophthalmology, Faculty of Medicine and Health, University of Sydney, Sydney 2006, Australia
| | - Darshan Parekh
- Rare Diseases Functional Genomics Laboratory, Sydney Children’s Hospitals Network and Children’s Medical Research Institute, Westmead, Sydney 2145, Australia; (D.P.); (L.G.R.)
| | - Lisa G. Riley
- Rare Diseases Functional Genomics Laboratory, Sydney Children’s Hospitals Network and Children’s Medical Research Institute, Westmead, Sydney 2145, Australia; (D.P.); (L.G.R.)
- Specialty of Child and Adolescent Health, University of Sydney, Westmead, Sydney 2145, Australia
| | - Elizabeth Farnsworth
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Sydney Genome Diagnostics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
| | - Bruce Bennetts
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Sydney Genome Diagnostics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
| | - Anai Gonzalez-Cordero
- Stem Cell Medicine Group, Children’s Medical Research Institute, University of Sydney, Westmead, Sydney 2145, Australia;
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney 2006, Australia
| | - Robyn V. Jamieson
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Department of Clinical Genetics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Correspondence: ; Tel.: +61-2-9687-2800; Fax: +61-2-9687-2120
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17
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Potter VL, Moye AR, Robichaux MA, Wensel TG. Super-resolution microscopy reveals photoreceptor-specific subciliary location and function of ciliopathy-associated protein CEP290. JCI Insight 2021; 6:e145256. [PMID: 34520396 PMCID: PMC8564900 DOI: 10.1172/jci.insight.145256] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 09/08/2021] [Indexed: 01/19/2023] Open
Abstract
Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multiorgan ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used super-resolution fluorescence microscopy and electron microscopy to localize CEP290 in the CC and in the primary cilia of cultured cells with subdiffraction resolution and to determine effects of CEP290 deficiency in 3 mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout the length of the CC whereas it is confined to the very base of primary cilia in human retinal pigment epithelium-1 cells. We found Y-shaped links, ciliary substructures between microtubules and membrane, throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. There were fewer cilia and no normal outer segments in the mutants, but the Y-shaped links were clearly present. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.
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Affiliation(s)
- Valencia L Potter
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology.,Program in Developmental Biology, Graduate School of Biomedical Sciences, and.,Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA
| | - Abigail R Moye
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology
| | - Michael A Robichaux
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology.,Departments of Ophthalmology and Biochemistry, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - Theodore G Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology
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18
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Georgiou M, Awadh Hashem S, Daich Varela M, Michaelides M. Gene Therapy in X-linked Retinitis Pigmentosa Due to Defects in RPGR. Int Ophthalmol Clin 2021; 61:97-108. [PMID: 34584047 DOI: 10.1097/iio.0000000000000384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Gumerson JD, Alsufyani A, Yu W, Lei J, Sun X, Dong L, Wu Z, Li T. Restoration of RPGR expression in vivo using CRISPR/Cas9 gene editing. Gene Ther 2021; 29:81-93. [PMID: 34257417 PMCID: PMC8856954 DOI: 10.1038/s41434-021-00258-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 11/29/2022]
Abstract
Mutations in the gene for Retinitis Pigmentosa GTPase Regulator (RPGR) cause the X-linked form of inherited retinal degeneration, and the majority are frameshift mutations in a highly repetitive, purine-rich region of RPGR known as the OFR15 exon. Truncation of the reading frame in this terminal exon ablates the functionally important C-terminal domain. We hypothesized that targeted excision in ORF15 by CRISPR/Cas9 and the ensuing repair by non-homologous end joining could restore RPGR reading frame in a portion of mutant photoreceptors thereby correcting gene function in vivo. We tested this hypothesis in the rd9 mouse, a naturally occurring mutant line that carries a frameshift mutation in RPGRORF15, through a combination of germline and somatic gene therapy approaches. In germline gene-edited rd9 mice, probing with RPGR domain-specific antibodies demonstrated expression of full length RPGRORF15 protein. Hallmark features of RPGR mutation-associated early disease phenotypes, such as mislocalization of cone opsins, were no longer present. Subretinal injections of the same guide RNA (sgRNA) carried in AAV sgRNA and SpCas9 expression vectors restored reading frame of RPGRORF15 in a subpopulation of cells with broad distribution throughout the retina, confirming successful correction of the mutation. These data suggest that a simplified form of genome editing mediated by CRISPR, as described here, could be further developed to repair RPGRORF15 mutations in vivo.
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Affiliation(s)
- Jessica D Gumerson
- Neurobiology Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute, Bethesda, MD, USA.
| | - Amal Alsufyani
- Neurobiology Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute, Bethesda, MD, USA.,King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia.,Montgomery College, Rockville, MD, USA
| | - Wenhan Yu
- Ocular Gene Therapy Core, National Eye Institute, Bethesda, MD, USA
| | - Jingqi Lei
- Genetic Engineering Core, National Eye Institute, Bethesda, MD, USA
| | - Xun Sun
- Neurobiology Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute, Bethesda, MD, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, Bethesda, MD, USA
| | - Zhijian Wu
- Ocular Gene Therapy Core, National Eye Institute, Bethesda, MD, USA
| | - Tiansen Li
- Neurobiology Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute, Bethesda, MD, USA.
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20
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Hadalin V, Šuštar M, Volk M, Maver A, Sajovic J, Jarc-Vidmar M, Peterlin B, Hawlina M, Fakin A. Cone Dystrophy Associated with a Novel Variant in the Terminal Codon of the RPGR- ORF15. Genes (Basel) 2021; 12:genes12040499. [PMID: 33805381 PMCID: PMC8066792 DOI: 10.3390/genes12040499] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/30/2022] Open
Abstract
Mutations in RPGRORF15 are associated with rod-cone or cone/cone-rod dystrophy, the latter associated with mutations at the distal end. We describe the phenotype associated with a novel variant in the terminal codon of the RPGRORF15 c.3457T>A (Ter1153Lysext*38), which results in a C-terminal extension. Three male patients from two families were recruited, aged 31, 35, and 38 years. Genetic testing was performed by whole exome sequencing. Filtered variants were analysed according to the population frequency, ClinVar database, the variant’s putative impact, and predicted pathogenicity; and were classified according to the ACMG guidelines. Examination included visual acuity (Snellen), colour vision (Ishihara), visual field, fundus autofluorescence (FAF), optical coherence tomography (OCT), and electrophysiology. All patients were myopic, and had central scotoma and reduced colour vision. Visual acuities on better eyes were counting fingers, 0.3 and 0.05. Electrophysiology showed severely reduced cone-specific responses and macular dysfunction, while the rod-specific response was normal. FAF showed hyperautofluorescent ring centred at the fovea encompassing an area of photoreceptor loss approximately two optic discs in diameter (3462–6342 μm). Follow up after 2–11 years showed enlargement of the diameter (avg. 100 μm/year). The novel c.3457T>A (Ter1153Lysext*38) mutation in the terminal RPGRORF15 codon is associated with cone dystrophy, which corresponds to the previously described phenotypes associated with mutations in the distal end of the RPGRORF15. Minimal progression during follow-up years suggests a relatively stable disease after the initial loss of the central cones.
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Affiliation(s)
- Vlasta Hadalin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Maja Šuštar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Marija Volk
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Aleš Maver
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Borut Peterlin
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
- Correspondence:
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Sánchez-Bellver L, Toulis V, Marfany G. On the Wrong Track: Alterations of Ciliary Transport in Inherited Retinal Dystrophies. Front Cell Dev Biol 2021; 9:623734. [PMID: 33748110 PMCID: PMC7973215 DOI: 10.3389/fcell.2021.623734] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
Ciliopathies are a group of heterogeneous inherited disorders associated with dysfunction of the cilium, a ubiquitous microtubule-based organelle involved in a broad range of cellular functions. Most ciliopathies are syndromic, since several organs whose cells produce a cilium, such as the retina, cochlea or kidney, are affected by mutations in ciliary-related genes. In the retina, photoreceptor cells present a highly specialized neurosensory cilium, the outer segment, stacked with membranous disks where photoreception and phototransduction occurs. The daily renewal of the more distal disks is a unique characteristic of photoreceptor outer segments, resulting in an elevated protein demand. All components necessary for outer segment formation, maintenance and function have to be transported from the photoreceptor inner segment, where synthesis occurs, to the cilium. Therefore, efficient transport of selected proteins is critical for photoreceptor ciliogenesis and function, and any alteration in either cargo delivery to the cilium or intraciliary trafficking compromises photoreceptor survival and leads to retinal degeneration. To date, mutations in more than 100 ciliary genes have been associated with retinal dystrophies, accounting for almost 25% of these inherited rare diseases. Interestingly, not all mutations in ciliary genes that cause retinal degeneration are also involved in pleiotropic pathologies in other ciliated organs. Depending on the mutation, the same gene can cause syndromic or non-syndromic retinopathies, thus emphasizing the highly refined specialization of the photoreceptor neurosensory cilia, and raising the possibility of photoreceptor-specific molecular mechanisms underlying common ciliary functions such as ciliary transport. In this review, we will focus on ciliary transport in photoreceptor cells and discuss the molecular complexity underpinning retinal ciliopathies, with a special emphasis on ciliary genes that, when mutated, cause either syndromic or non-syndromic retinal ciliopathies.
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Affiliation(s)
- Laura Sánchez-Bellver
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
| | - Vasileios Toulis
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
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22
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Moreno-Leon L, West EL, O’Hara-Wright M, Li L, Nair R, He J, Anand M, Sahu B, Chavali VRM, Smith AJ, Ali RR, Jacobson SG, Cideciyan AV, Khanna H. RPGR isoform imbalance causes ciliary defects due to exon ORF15 mutations in X-linked retinitis pigmentosa (XLRP). Hum Mol Genet 2021; 29:3706-3716. [PMID: 33355362 PMCID: PMC7823108 DOI: 10.1093/hmg/ddaa269] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 12/28/2022] Open
Abstract
Mutations in retinitis pigmentosa GTPase regulator (RPGR) cause severe retinal ciliopathy, X-linked retinitis pigmentosa. Although two major alternatively spliced isoforms, RPGRex1-19 and RPGRORF15, are expressed, the relative importance of these isoforms in disease pathogenesis is unclear. Here, we analyzed fibroblast samples from eight patients and found that all of them form longer cilia than normal controls, albeit to different degrees. Although all mutant RPGRORF15 messenger RNAs (mRNAs) are unstable, their steady-state levels were similar or higher than those in the control cells, suggesting there may be increased transcription. Three of the fibroblasts that had higher levels of mutant RPGRORF15 mRNA also exhibited significantly higher levels of RPGRex1-19 mRNA. Four samples with unaltered RPGRex1-19 levels carried mutations in RPGRORF15 that resulted in this isoform being relatively less stable. Thus, in all cases, the RPGRex1-19/RPGRORF15 isoform ratio was increased, and this was highly correlative to the cilia extension defect. Moreover, overexpression of RPGRex1-19 (mimicking the increase in RPGRex1-19 to RPGRORF15 isoform ratio) or RPGRORF15 (mimicking reduction of the ratio) resulted in significantly longer or shorter cilia, respectively. Notably, the cilia length defect appears to be attributable to both the loss of the wild-type RPGRORF15 protein and to the higher levels of the RPGRex1-19 isoform, indicating that the observed defect is due to the altered isoform ratios. These results suggest that maintaining the optimal RPGRex1-9 to RPGRORF15 ratio is critical for cilia growth and that designing strategies that focus on the best ways to restore the RPGRex1-19/RPGRORF15 ratio may lead to better therapeutic outcomes.
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Affiliation(s)
- Laura Moreno-Leon
- Department of Ophthalmology & Visual Sciences, UMass Medical School, Worcester, MA 01655, USA
| | - Emma L West
- Division of Molecular Therapy, UCL Institute of Ophthalmology, London EC1V 9El, UK
| | | | - Linjing Li
- Department of Ophthalmology & Visual Sciences, UMass Medical School, Worcester, MA 01655, USA
| | - Rohini Nair
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jie He
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Manisha Anand
- Department of Ophthalmology & Visual Sciences, UMass Medical School, Worcester, MA 01655, USA
| | - Bhubanananda Sahu
- Department of Ophthalmology & Visual Sciences, UMass Medical School, Worcester, MA 01655, USA
| | | | - Alexander J Smith
- Division of Molecular Therapy, UCL Institute of Ophthalmology, London EC1V 9El, UK
| | - Robin R Ali
- Division of Molecular Therapy, UCL Institute of Ophthalmology, London EC1V 9El, UK
| | - Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Artur V Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hemant Khanna
- Department of Ophthalmology & Visual Sciences, UMass Medical School, Worcester, MA 01655, USA
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Hu S, Du J, Chen N, Jia R, Zhang J, Liu X, Yang L. In Vivo CRISPR/Cas9-Mediated Genome Editing Mitigates Photoreceptor Degeneration in a Mouse Model of X-Linked Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2020; 61:31. [PMID: 32330228 PMCID: PMC7401909 DOI: 10.1167/iovs.61.4.31] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Retinitis pigmentosa GTPase regulator (RPGR)-related X-linked retinitis pigmentosa is associated with one of the most severe phenotypes among inherited retinal disease. The aim of this study was to investigate Clustered Regularly Interspaced Short Palindromic Repeat/Cas9-mediated gene editing therapy in a mouse model of Rpgr. Methods The Rpgr−/yCas9+/WT male mice were used for this study. At 6 months of age, they received a single subretinal injection of adeno-associated virus vectors carrying sgRNA and donor template separately, and therapeutic effect was examined after 1, 6, and 12 months. Results Rpgr knockout mouse showed slow but progressive age-related retinal degeneration, which emulates the disease occurring in humans. Significant photoreceptor preservation was observed in the treated part of the retina, in sharp contrast to the untreated part of the retina in the same eye after 6 and 12 months. It was surprising that precise modification at the target locus as demonstrated by genomic DNA sequencing in the post-mitotic photoreceptor was observed. Moreover, the therapeutic effect lasts for up to 12 months and no off-target effects were shown. Conclusions Our study strongly demonstrates that gene editing therapy is a promising therapeutic strategy to treat inherited retinal degeneration.
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McKenzie CW, Lee L. Genetic interaction between central pair apparatus genes CFAP221, CFAP54, and SPEF2 in mouse models of primary ciliary dyskinesia. Sci Rep 2020; 10:12337. [PMID: 32704025 PMCID: PMC7378221 DOI: 10.1038/s41598-020-69359-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/06/2020] [Indexed: 12/21/2022] Open
Abstract
Primary ciliary dyskinesia (PCD) is a genetically heterogeneous syndrome that results from defects in motile cilia. The ciliary axoneme has a 9 + 2 microtubule structure consisting of nine peripheral doublets surrounding a central pair apparatus (CPA), which plays a critical role in regulating proper ciliary function. We have previously shown that mouse models with mutations in CPA genes CFAP221, CFAP54, and SPEF2 have a PCD phenotype with defects in ciliary motility. In this study, we investigated potential genetic interaction between these CPA genes by generating each combination of double heterozygous and double homozygous mutants. No detectable cilia-related phenotypes were observed in double heterozygotes, but all three double homozygous mutant lines exhibit early mortality and typically develop severe PCD-associated phenotypes of hydrocephalus, mucociliary clearance defects in the upper airway, and abnormal spermatogenesis. Double homozygous cilia are generally intact and display a normal morphology and distribution. Spermiogenesis is aborted in double homozygotes, with an absence of mature flagella on elongating spermatids and epididymal sperm. These findings identify genetic interactions between CPA genes and genetic mechanisms regulating the CPA and motile cilia function.
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Affiliation(s)
- Casey W McKenzie
- Pediatrics and Rare Diseases Group, Sanford Research, 2301 E. 60th Street N., Sioux Falls, SD, 57104, USA
| | - Lance Lee
- Pediatrics and Rare Diseases Group, Sanford Research, 2301 E. 60th Street N., Sioux Falls, SD, 57104, USA. .,Department of Pediatrics, Sanford School of Medicine of the University of South Dakota, 1400 W. 22nd Street, Sioux Falls, SD, 57105, USA.
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Zou X, Fang S, Wu S, Li H, Sun Z, Zhu T, Wei X, Sui R. Detailed comparison of phenotype between male patients carrying variants in exons 1-14 and ORF15 of RPGR. Exp Eye Res 2020; 198:108147. [PMID: 32702353 DOI: 10.1016/j.exer.2020.108147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/05/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022]
Abstract
PURPOSE To compare disease severity in detail between patients carrying variants in exons 1-14 and ORF15 of retinitis pigmentosa GTPase regulator (RPGR). METHODS Systematic next-generation sequencing data analysis, Sanger sequencing validation and segregation analysis were utilised to identify the pathogenic variants. Detailed ophthalmic examinations, including electroretinograms, fundus photography, fundus autofluorescence and optical coherence tomography were performed. Statistical analysis, including age adjustment and comparison, were performed based on cross-sectional level to compare disease severity between variants in the two RPGR variant groups. RESULTS Sixty-two variants were identified in RPGR in 86 patients from 77 unrelated families. Twenty-nine (37.7%) had variants in RPGR-exons 1-14 (group 1) and 48 (62.3%) in RPGR-ORF15 (group 2). Eighty-four patients were diagnosed with X-linked retinitis pigmentosa and only two patients with cone-rod dystrophy. LogMAR visual acuity increased 0.035 and 0.022 each year on average in group 1 and group 2, respectively. Group 2 patients had better visual acuity with a mean logMAR difference of 0.4378, which is significant after age adjustment (P < 0.01). Neither the value of log (ellipsoid zone width) nor central retinal thickness was significantly correlated with variant grouping after considering the effect of the age variable (P = 0.56 and 0.40, respectively). Spherical refractive error did not differ significantly between the two variant groups (P = 0.17). Patterns of autofluorescence included a hyperfluorescent ring at the posterior pole, diffuse hyperfluorescence in the macular area, and dark macular autofluorescence with or without fovea hyperfluorescence. The age and proportion of fundus autofluorescence patterns between the two variant groups were significantly different (P < 0.01). CONCLUSIONS Patients with variants in exons 1-14 retained less visual acuity than patients with ORF15 variants and deteriorated faster. However, the ellipsoid zone widths, central retinal thickness and refractions were comparable between the two groups. Autofluorescence pattern relates to the age and the variant grouping.
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Affiliation(s)
- Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Sha Fang
- School of Statistics, Capital University of Economics and Business, Beijing, 100070, China
| | - Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xing Wei
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.
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Moore SM, Skowronska-Krawczyk D, Chao DL. Targeting of the NRL Pathway as a Therapeutic Strategy to Treat Retinitis Pigmentosa. J Clin Med 2020; 9:E2224. [PMID: 32668775 DOI: 10.3390/jcm9072224] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/28/2020] [Accepted: 07/07/2020] [Indexed: 12/26/2022] Open
Abstract
Retinitis pigmentosa (RP) is an inherited retinal dystrophy (IRD) with a prevalence of 1:4000, characterized by initial rod photoreceptor loss and subsequent cone photoreceptor loss with accompanying nyctalopia, visual field deficits, and visual acuity loss. A diversity of causative mutations have been described with autosomal dominant, autosomal recessive, and X-linked inheritance and sporadic mutations. The diversity of mutations makes gene therapy challenging, highlighting the need for mutation-agnostic treatments. Neural leucine zipper (NRL) and NR2E3 are factors important for rod photoreceptor cell differentiation and homeostasis. Germline mutations in NRL or NR2E3 leads to a loss of rods and an increased number of cones with short wavelength opsin in both rodents and humans. Multiple groups have demonstrated that inhibition of NRL or NR2E3 activity in the mature retina could endow rods with certain properties of cones, which prevents cell death in multiple rodent RP models with diverse mutations. In this review, we summarize the literature on NRL and NR2E3, therapeutic strategies of NRL/NR2E3 modulation in preclinical RP models, as well as future directions of research. In summary, inhibition of the NRL/NR2E3 pathway represents an intriguing mutation agnostic and disease-modifying target for the treatment of RP.
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kleine Holthaus SM, Aristorena M, Maswood R, Semenyuk O, Hoke J, Hare A, Smith AJ, Mole SE, Ali RR. Gene Therapy Targeting the Inner Retina Rescues the Retinal Phenotype in a Mouse Model of CLN3 Batten Disease. Hum Gene Ther 2020; 31:709-718. [PMID: 32578444 PMCID: PMC7404834 DOI: 10.1089/hum.2020.038] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs), often referred to as Batten disease, are inherited lysosomal storage disorders that represent the most common neurodegeneration during childhood. Symptoms include seizures, vision loss, motor and cognitive decline, and premature death. The development of brain-directed treatments for NCLs has made noteworthy progress in recent years. Clinical trials are currently ongoing or planned for different forms of the disease. Despite these promising advances, it is unlikely that therapeutic interventions targeting the brain will prevent loss of vision in patients as retinal cells remain untreated and will continue to degenerate. Here, we demonstrate that Cln3Δex7/8 mice, a mouse model of CLN3 Batten disease with juvenile onset, suffer from a decline in inner retinal function resulting from the death of rod bipolar cells, interneurons vital for signal transmission from photoreceptors to ganglion cells in the retina. We also show that this ocular phenotype can be treated by adeno-associated virus (AAV)-mediated expression of CLN3 in cells of the inner retina, leading to significant survival of bipolar cells and preserved retinal function. In contrast, the treatment of photoreceptors, which are lost in patients at late disease stages, was not therapeutic in Cln3Δex7/8 mice, underlining the notion that CLN3 disease is primarily a disease of the inner retina with secondary changes in the outer retina. These data indicate that bipolar cells play a central role in this disease and identify this cell type as an important target for ocular AAV-based gene therapies for CLN3 disease.
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Affiliation(s)
| | - Mikel Aristorena
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Ryea Maswood
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Olha Semenyuk
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Justin Hoke
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Aura Hare
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Alexander J. Smith
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Sara E. Mole
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- UCL Institute of Child Health, London, United Kingdom
- UCL Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Robin R. Ali
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- Correspondence: Prof. Robin R. Ali, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, United Kingdom.
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Rozpędek-Kamińska W, Wojtczak R, Szaflik JP, Szaflik J, Majsterek I. The Genetic and Endoplasmic Reticulum-Mediated Molecular Mechanisms of Primary Open-Angle Glaucoma. Int J Mol Sci 2020; 21:E4171. [PMID: 32545285 DOI: 10.3390/ijms21114171] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 12/14/2022] Open
Abstract
Glaucoma is a heterogenous, chronic, progressive group of eye diseases, which results in irreversible loss of vision. There are several types of glaucoma, whereas the primary open-angle glaucoma (POAG) constitutes the most common type of glaucoma, accounting for three-quarters of all glaucoma cases. The pathological mechanisms leading to POAG pathogenesis are multifactorial and still poorly understood, but it is commonly known that significantly elevated intraocular pressure (IOP) plays a crucial role in POAG pathogenesis. Besides, genetic predisposition and aggregation of abrogated proteins within the endoplasmic reticulum (ER) lumen and subsequent activation of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent unfolded protein response (UPR) signaling pathway may also constitute important factors for POAG pathogenesis at the molecular level. Glaucoma is commonly known as a ‘silent thief of sight’, as it remains asymptomatic until later stages, and thus its diagnosis is frequently delayed. Thereby, detailed knowledge about the glaucoma pathophysiology is necessary to develop both biochemical and genetic tests to improve its early diagnosis as well as develop a novel, ground-breaking treatment strategy, as currently used medical therapies against glaucoma are limited and may evoke numerous adverse side-effects in patients.
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Collin GB, Gogna N, Chang B, Damkham N, Pinkney J, Hyde LF, Stone L, Naggert JK, Nishina PM, Krebs MP. Mouse Models of Inherited Retinal Degeneration with Photoreceptor Cell Loss. Cells 2020; 9:cells9040931. [PMID: 32290105 PMCID: PMC7227028 DOI: 10.3390/cells9040931] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degeneration (RD) leads to the impairment or loss of vision in millions of individuals worldwide, most frequently due to the loss of photoreceptor (PR) cells. Animal models, particularly the laboratory mouse, have been used to understand the pathogenic mechanisms that underlie PR cell loss and to explore therapies that may prevent, delay, or reverse RD. Here, we reviewed entries in the Mouse Genome Informatics and PubMed databases to compile a comprehensive list of monogenic mouse models in which PR cell loss is demonstrated. The progression of PR cell loss with postnatal age was documented in mutant alleles of genes grouped by biological function. As anticipated, a wide range in the onset and rate of cell loss was observed among the reported models. The analysis underscored relationships between RD genes and ciliary function, transcription-coupled DNA damage repair, and cellular chloride homeostasis. Comparing the mouse gene list to human RD genes identified in the RetNet database revealed that mouse models are available for 40% of the known human diseases, suggesting opportunities for future research. This work may provide insight into the molecular players and pathways through which PR degenerative disease occurs and may be useful for planning translational studies.
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Affiliation(s)
- Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Navdeep Gogna
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Nattaya Damkham
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Jai Pinkney
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lillian F. Hyde
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Jürgen K. Naggert
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
| | - Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
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Appelbaum T, Santana E, Aguirre GD. Critical Decrease in the Level of Axon Guidance Receptor ROBO1 in Rod Synaptic Terminals Is Followed by Axon Retraction. Invest Ophthalmol Vis Sci 2020; 61:11. [PMID: 32176262 PMCID: PMC7405958 DOI: 10.1167/iovs.61.3.11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/14/2019] [Indexed: 12/24/2022] Open
Abstract
Purpose To define remodeling of photoreceptor synaptic terminals and second-order retinal neurons in canine X-linked progressive retinal atrophy 1 caused by a five-nucleotide deletion in the RPGR exon ORF15. Methods Retinas of normal and mutant dogs were used for gene expression, Western blot, and immunohistochemistry. Cell-specific markers were used to examine disease-dependent retinal remodeling. Results In mutant retinas, a number of rod axon terminals retract into the outer nuclear layer. This neuritic atrophy preceded significant loss of rods and was evident early in disease. Rod bipolar and horizontal cell processes were found to extend into the outer nuclear layer, where they seemed to form contacts with the spherules of rod photoreceptors. No ectopic rewiring was observed. Because cytoskeletal reorganization was previously shown to underlie photoreceptor axon retraction, we examined normal and mutant retinas for expression of axon guidance receptors ROBO1 and ROBO2, which are known to regulate actin cytoskeleton dynamics. We found that the overall expression of both ROBO1 and ROBO2 is retained at the same level in premature and fully developed normal retinas. However, analysis of predisease and early disease retinas identified markedly decreased levels of ROBO1 in rod spherules compared with controls. In contrast, no differences in ROBO1 signals were noted in cone pedicles in normal and mutant retinas, where ROBO1 levels remained similarly low. Conclusions Depletion of ROBO1 in rod synaptic terminals correlates with the remodeling of axonal and dendritic processes in the outer retina of dogs with X-linked progressive retinal atrophy 1 and may play a role in the retraction of rod axons.
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Affiliation(s)
- Tatyana Appelbaum
- Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Evelyn Santana
- Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Gustavo D. Aguirre
- Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Orlans HO, Merrill J, Barnard AR, Charbel Issa P, Peirson SN, MacLaren RE. Filtration of Short-Wavelength Light Provides Therapeutic Benefit in Retinitis Pigmentosa Caused by a Common Rhodopsin Mutation. Invest Ophthalmol Vis Sci 2019; 60:2733-2742. [PMID: 31247114 DOI: 10.1167/iovs.19-26964] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The role of light exposure in accelerating retinitis pigmentosa (RP) remains controversial. Faster degeneration has however been observed in the inferior than superior retina in several forms ("sector" RP), including those caused by the rhodopsin P23H mutation, suggesting a modifying role of incident light exposure in such cases. Rearing of equivalent animal models in complete darkness has been shown to slow the degeneration. Here we investigate the use of red filters as a potential treatment strategy, with the hypothesis that minimizing retinal exposure to light <600 nm to which rods are maximally sensitive may provide therapeutic benefit. Methods Knockin mice heterozygous for the P23H dominant rhodopsin mutation (RhoP23H/+) housed in red-tinted plastic cages were divided at weaning into either untinted or red-tinted cages. Subsequently, photoreceptor layer (PRL) thickness was measured by spectral-domain ocular coherence tomography, retinal function quantified by ERG, and cone morphology determined by immunohistochemical analysis (IHC) of retinal flatmounts. Results Mice remaining in red-tinted cages had a significantly greater PRL thickness than those housed in untinted cages at all time points. Red housing also led to a highly significant rescue of retinal function as determined by both dark- and light-adapted ERG responses. IHC further revealed a dramatic benefit on cone morphology and number in the red- as compared with the clear-housed group. Conclusions Limitation of short-wavelength light exposure significantly slows degeneration in the RhoP23H/+ mouse model. Red filters may represent a cost-effective and low-risk treatment for patients with rod-cone dystrophy in whom a sectoral phenotype is noted.
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Affiliation(s)
- Harry O Orlans
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom.,Western Eye Hospital, London, United Kingdom
| | - Jonathon Merrill
- Biomedical Services, University of Oxford, Oxford, United Kingdom
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
| | - Peter Charbel Issa
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom.,Oxford Eye Hospital, Oxford, United Kingdom
| | - Stuart N Peirson
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom.,Oxford Eye Hospital, Oxford, United Kingdom
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Joe MK, Li W, Hiriyanna S, Yu W, Shah SA, Abu-Asab M, Qian H, Wu Z. A Common Outer Retinal Change in Retinal Degeneration by Optical Coherence Tomography Can Be Used to Assess Outcomes of Gene Therapy. Hum Gene Ther 2019; 30:1520-1530. [PMID: 31672061 DOI: 10.1089/hum.2019.162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Identifying early disease hallmarks in animal models with slow disease progression may expedite disease detection and assessment of treatment outcomes. Using optical coherence tomography, a widely applied noninvasive method for monitoring retinal structure changes, we analyzed retinal optical sections from six mouse lines with retinal degeneration caused by mutations in different disease-causing genes. While images from wild-type mice revealed four well-separated hyper-reflective bands in the outer retina (designated as outer retina reflective bands, ORRBs) at all ages, the second band (ORRB2) and the third band (ORRB3) were merged in retinas of five mutant mouse lines at early ages, suggesting the pathological nature of this alteration. This ORRB change appeared to be degenerating photoreceptor related, and occurred before obvious morphological changes that can be identified on both hematoxylin and eosin-stained sections and electron microscopic sections. Importantly, the merging of ORRB2 and ORRB3 was reversed by treatment with adeno-associated viral vector-mediated gene replacement therapies, and this restoration occurred much earlier than measurable functional or structural improvement. Our data suggest that the ORRB change could be a common hallmark of early retinal degeneration and its restoration could be used for rapid and noninvasive assessment of therapeutic effects following gene therapy or other treatment interventions.
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Affiliation(s)
- Myung Kuk Joe
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Wenbo Li
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Suja Hiriyanna
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Wenhan Yu
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Shreya A Shah
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Mones Abu-Asab
- Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Zhijian Wu
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
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Li XX, Yuan XJ, Zhai Y, Yu S, Jia RX, Yang LP, Ma ZZ, Zhao YM, Wang YX, Ge LH. Treatment with Stem Cells from Human Exfoliated Deciduous Teeth and Their Derived Conditioned Medium Improves Retinal Visual Function and Delays the Degeneration of Photoreceptors. Stem Cells Dev 2019; 28:1514-1526. [PMID: 31544584 DOI: 10.1089/scd.2019.0158] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Retinitis pigmentosa (RP) is a hereditary disease characterized by degeneration and the loss of photoreceptors. Stem cell-based therapy has emerged as a promising strategy for treating RP. Stem cells from exfoliated deciduous teeth (SHEDs), a type of mesenchymal stem cell from human exfoliated deciduous teeth, have the potential to differentiate into photoreceptor-like cells under specific induction in vitro. It has been confirmed that through paracrine secreta, SHEDs exert neurotrophic, angiogenic, immunoregulatory, and antiapoptotic functions in injured tissues. This study was designed to determine whether retinal-differentiated SHEDs and the conditioned medium derived from SHEDs (SHEDs-CM) have therapeutic effects in a mouse model of RP. The results showed that both SHEDs and SHEDs-CM improved electroretinogram responses, ameliorated photoreceptor degeneration, and maintained the structure of the outer segments of photoreceptors. The therapeutic effects were related to antiapoptotic activity of SHEDs and SHEDs-CM. Thus, SHEDs may be a promising stem cell source for treating retinal degeneration.
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Affiliation(s)
- Xiao-Xia Li
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Xiao-Jing Yuan
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Yue Zhai
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Shi Yu
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Rui-Xuan Jia
- Institute of Systems Biomedicine and Department of Ophthalmology, School of Basic Medical Sciences, Peking University Third Hospital, Beijing, China
| | - Li-Ping Yang
- Institute of Systems Biomedicine and Department of Ophthalmology, School of Basic Medical Sciences, Peking University Third Hospital, Beijing, China
| | - Zhi-Zhong Ma
- Institute of Systems Biomedicine and Department of Ophthalmology, School of Basic Medical Sciences, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yu-Ming Zhao
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Yi-Xiang Wang
- Central Laboratory, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Li-Hong Ge
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing, China
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Abstract
Ciliopathies display extensive genetic and clinical heterogeneity, varying in severity, age of onset, disease progression and organ systems affected. Retinal involvement, as demonstrated by photoreceptor dysfunction or death, is a highly penetrant phenotype among a vast majority of ciliopathies. Photoreceptor cells possess a specialized and modified sensory cilium with membrane discs where efficient photon capture and ensuing signaling cascade initiate the visual process. Disruptions of cilia biogenesis and protein transport lead to impairment of photoreceptor function and eventually degeneration. Despite advances in elucidation of ciliogenesis and photoreceptor cilia defects, we have limited understanding of pathogenic mechanisms underlying retinal phenotype(s) observed in human ciliopathies. Patient-derived induced pluripotent stem cell (iPSC)-based approaches offer a unique opportunity to complement studies with model organisms and examine cilia disease relevant to humans. Three-dimensional retinal organoids from iPSC lines feature laminated cytoarchitecture, apical-basal polarity and emergence of a ciliary structure, thereby permitting pathogenic modeling of human photoreceptors in vitro. Here, we review the biology of photoreceptor cilia and associated defects and discuss recent progress in evolving treatment modalities, especially using patient-derived iPSCs, for retinal ciliopathies.
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Affiliation(s)
- Holly Yu Chen
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Emily Welby
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Tiansen Li
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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Abstract
This article summarizes the recent advances in our understanding of a major retinal disease gene RPGR (retinitis pigmentosa GTPase regulator), mutations in which are associated with majority of X-linked forms of retinal degenerations. A great deal of work has been done to uncover the ciliary localization of RPGR and its interacting proteins in the retina. However, the molecular mechanisms of action of RPGR in the photoreceptors are still unclear. Recent studies have begun to shed light on the intracellular pathways in which RPGR is likely involved. The deregulation of such pathways may underlie the pathogenesis of severe retinal degeneration associated with RPGR. With the recent advances in the gene augmentation therapy for RPGR-associated disease, there is a lot of excitement in the field. Patients with RPGR mutations, however, present with clinically heterogeneous manifestations. It is therefore imperative to examine the function of RPGR in detail, so that we can design patient-oriented therapeutic strategies for this disease.
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Affiliation(s)
- Hemant Khanna
- Department of Ophthalmology and Neurobiology, UMASS Medical School, Worcester, MA, USA.
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Tang PH, Jauregui R, Tsang SH, Bassuk AG, Mahajan VB. Optical Coherence Tomography Angiography of RPGR-Associated Retinitis Pigmentosa Suggests Foveal Avascular Zone is a Biomarker for Vision Loss. Ophthalmic Surg Lasers Imaging Retina 2019; 50:e44-e48. [PMID: 30768229 DOI: 10.3928/23258160-20190129-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/03/2018] [Indexed: 01/07/2023]
Abstract
RPGR-associated retinitis pigmentosa (RP) is a progressive disease with retina degeneration. Optical coherence tomography angiography (OCTA) is an imaging technique that provides novel insights. The authors report two affected male siblings who underwent OCTA imaging. The area of the foveal avascular zone (FAZ) was measured. Although the younger sibling exhibited more advanced clinical disease, his visual acuity was superior to his older sibling. OCTA imaging revealed a better preserved FAZ in the younger sibling as the reason for this. It also highlighted attenuation of choriocapillaris / choroid layers as biomarkers for disease severity. This provides new insights into retinal degeneration in RPGR-associated RP. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e44-e48.].
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Zhang X, Shahani U, Reilly J, Shu X. Disease mechanisms and neuroprotection by tauroursodeoxycholic acid in Rpgr knockout mice. J Cell Physiol 2019; 234:18801-18812. [PMID: 30924157 DOI: 10.1002/jcp.28519] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/22/2019] [Accepted: 03/06/2019] [Indexed: 12/16/2022]
Abstract
Mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene are the predominant cause of retinitis pigmentosa. RPGR plays a critical role as a scaffold protein in the regulation of protein trafficking from the basal body to the axoneme, where the cargoes are transported to the outer segments (OSs) of photoreceptors. This trafficking process is controlled directly by intraflagellar transport complexes and regulated by the RPGR protein complex, although the precise mechanisms have yet to be defined. We used an Rpgr conditional knockout (cko) mouse model to investigate the disease mechanisms during retinal degeneration and to evaluate the protective effects of tauroursodeoxycholic acid (TUDCA). Rhodopsin, cone opsins and transducin were mislocalized in Rpgr cko photoreceptors, while localization of NPHP4 to connecting cilia was absent, suggesting that RPGR is required for ciliary protein trafficking. Microglia were activated in advance of retinal degeneration in Rpgr cko mouse retinas. TUDCA treatment suppressed microglial activation and inflammation and prevented photoreceptor degeneration in Rpgr cko mice. Our data demonstrated that TUDCA has therapeutic potential for RPGR-associated RP patients.
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Affiliation(s)
- Xun Zhang
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland
| | - Uma Shahani
- Department of Vision Science, Glasgow Caledonian University, Glasgow, Scotland
| | - James Reilly
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland
| | - Xinhua Shu
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland.,Department of Vision Science, Glasgow Caledonian University, Glasgow, Scotland
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38
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Li X, Xie J, Zhai Y, Fang T, Rao N, Hu S, Yang L, Zhao Y, Wang Y, Ge L. Differentiation of Stem Cells from Human Exfoliated Deciduous Teeth into Retinal Photoreceptor-Like Cells and Their Sustainability In Vivo. Stem Cells Int. 2019;2019:2562981. [PMID: 30906327 PMCID: PMC6393909 DOI: 10.1155/2019/2562981] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/08/2018] [Accepted: 12/03/2018] [Indexed: 01/14/2023] Open
Abstract
Retinal degeneration is characterized by the progressive loss of photoreceptors, and stem cell therapy has become a promising strategy. Many studies have reported that mesenchymal stem cell transplantation can sustain retinal structure and prolong retinal functions based on two mechanisms. One is cell replacement, and the other is the paracrine action of stem cells. Cells from human exfoliated deciduous teeth (SHEDs) show characteristics typical of mesenchymal stem cells. They are derived from the neural crest and are a potential cellular source for neural regeneration in stem cell therapy. In this study, we explored the potential of SHEDs to be induced towards the retinal photoreceptor phenotype and to be sustainable in an animal model of retinal degeneration. A factor-cocktail protocol was used to induce SHEDs towards retinal photoreceptors for 24 days, and the characteristics of the induced cells were identified in terms of morphological changes, biomarker expression and subcellular distribution, and calcium influx. SHEDs were labeled with firefly luciferase for in vivo tracking by bioluminescent imaging and then transplanted into the subretinal space of mice. Our results showed that SHEDs successfully transdifferentiated into photoreceptor-like cells, which displayed neuron-like morphology, and expressed specific genes and proteins associated with retinal precursors, photoreceptor precursors, and mature photoreceptors. In addition, calcium influx was significantly greater in the retinal-induced than in noninduced SHEDs. In vivo tracking confirmed at least 2 weeks of good survival by bioluminescent imaging and 3 months of sustainability of SHEDs by histological analysis. We conclude that SHEDs have the potential to transdifferentiate into retinal photoreceptor-like cells in vitro and maintain good viability in vivo after transplantation into mice with a normal immune system. This demonstrates preliminary success in generating photoreceptor-like cells from SHEDs and applying SHEDs in treating retinal degeneration.
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Ying G, Frederick JM, Baehr W. Deletion of both centrin 2 (CETN2) and CETN3 destabilizes the distal connecting cilium of mouse photoreceptors. J Biol Chem 2019; 294:3957-3973. [PMID: 30647131 DOI: 10.1074/jbc.ra118.006371] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/09/2019] [Indexed: 02/03/2023] Open
Abstract
Centrins (CETN1-4) are ubiquitous and conserved EF-hand-family Ca2+-binding proteins associated with the centrosome, basal body, and transition zone. Deletion of CETN1 or CETN2 in mice causes male infertility or dysosmia, respectively, without affecting photoreceptor function. However, it remains unclear to what extent centrins are redundant with each other in photoreceptors. Here, to explore centrin redundancy, we generated Cetn3 GT/GT single-knockout and Cetn2 -/-;Cetn3 GT/GT double-knockout mice. Whereas the Cetn3 deletion alone did not affect photoreceptor function, simultaneous ablation of Cetn2 and Cetn3 resulted in attenuated scotopic and photopic electroretinography (ERG) responses in mice at 3 months of age, with nearly complete retina degeneration at 1 year. Removal of CETN2 and CETN3 activity from the lumen of the connecting cilium (CC) destabilized the photoreceptor axoneme and reduced the CC length as early as postnatal day 22 (P22). In Cetn2 -/-;Cetn3 GT/GT double-knockout mice, spermatogenesis-associated 7 (SPATA7), a key organizer of the photoreceptor-specific distal CC, was depleted gradually, and CETN1 was condensed to the mid-segment of the CC. Ultrastructural analysis revealed that in this double knockout, the axoneme of the CC expanded radially at the distal end, with vertically misaligned outer segment discs and membrane whorls. These observations suggest that CETN2 and CETN3 cooperate in stabilizing the CC/axoneme structure.
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Affiliation(s)
- Guoxin Ying
- From the Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, Utah 84132,
| | - Jeanne M Frederick
- From the Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, Utah 84132
| | - Wolfgang Baehr
- From the Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, Utah 84132, .,the Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah 84112, and.,the Department of Biology, University of Utah, Salt Lake City, Utah 84132
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40
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Lee JH, Wang JH, Chen J, Li F, Edwards TL, Hewitt AW, Liu GS. Gene therapy for visual loss: Opportunities and concerns. Prog Retin Eye Res 2019; 68:31-53. [DOI: 10.1016/j.preteyeres.2018.08.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 08/23/2018] [Accepted: 08/26/2018] [Indexed: 12/17/2022]
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41
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Schlegel J, Hoffmann J, Röll D, Müller B, Günther S, Zhang W, Janise A, Vössing C, Fühler B, Neidhardt J, Khanna H, Lorenz B, Stieger K. Toward genome editing in X-linked RP-development of a mouse model with specific treatment relevant features. Transl Res 2019; 203:57-72. [PMID: 30213530 PMCID: PMC6294733 DOI: 10.1016/j.trsl.2018.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 08/16/2018] [Accepted: 08/16/2018] [Indexed: 01/06/2023]
Abstract
Genome editing represents a powerful tool to treat inherited disorders. Highly specific endonucleases induce a DNA double strand break near the mutant site, which is subsequently repaired by cellular DNA repair mechanisms that involve the presence of a wild type template DNA. In vivo applications of this strategy are still rare, in part due to the absence of appropriate animal models carrying human disease mutations and knowledge of the efficient targeting of endonucleases. Here we report the generation and characterization of a new mouse model for X-linked retinitis pigmentosa (XLRP) carrying a point mutation in the mutational hotspot exon ORF15 of the RPGR gene as well as a recognition site for the homing endonuclease I-SceI. Presence of the genomic modifications was verified at the RNA and protein levels. The mutant protein was observed at low levels. Optical coherence tomography studies revealed a slowly progressive retinal degeneration with photoreceptor loss starting at 9 months of age, paralleling the onset of functional deficits as seen in the electroretinogram. Early changes to the outer retinal bands can be used as biomarker during treatment applications. We further show for the first time efficient targeting using the I-SceI enzyme at the genomic locus in a proof of concept in photoreceptors following adeno-associated virus mediated gene transfer in vivo. Taken together, our studies not only provide a human-XLRP disease model but also act as a platform to design genome editing technology for retinal degenerative diseases using the currently available endonucleases.
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Affiliation(s)
- J Schlegel
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - J Hoffmann
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - D Röll
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - B Müller
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - S Günther
- Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - W Zhang
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - A Janise
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - C Vössing
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - B Fühler
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - J Neidhardt
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany; Research Center Neurosensory Science, University Oldenburg, Oldenburg, Germany
| | - H Khanna
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - B Lorenz
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - K Stieger
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany.
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Baehr W, Hanke-Gogokhia C, Sharif A, Reed M, Dahl T, Frederick JM, Ying G. Insights into photoreceptor ciliogenesis revealed by animal models. Prog Retin Eye Res 2018; 71:26-56. [PMID: 30590118 DOI: 10.1016/j.preteyeres.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
Photoreceptors are polarized neurons, with very specific subcellular compartmentalization and unique requirements for protein expression and trafficking. Each photoreceptor contains an outer segment, the site of photon capture that initiates vision, an inner segment that houses the biosynthetic machinery and a synaptic terminal for signal transmission to downstream neurons. Outer segments and inner segments are connected by a connecting cilium (CC), the equivalent of a transition zone (TZ) of primary cilia. The connecting cilium is part of the basal body/axoneme backbone that stabilizes the outer segment. This report will update the reader on late developments in photoreceptor ciliogenesis and transition zone formation, specifically in mouse photoreceptors, focusing on early events in photoreceptor ciliogenesis. The connecting cilium, an elongated and narrow structure through which all outer segment proteins and membrane components must traffic, functions as a gate that controls access to the outer segment. Here we will review genes and their protein products essential for basal body maturation and for CC/TZ genesis, sorted by phenotype. Emphasis is given to naturally occurring mouse mutants and gene knockouts that interfere with CC/TZ formation and ciliogenesis.
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Affiliation(s)
- Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA.
| | - Christin Hanke-Gogokhia
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Ali Sharif
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Michelle Reed
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Tiffanie Dahl
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Guoxin Ying
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
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Zhang L, Sun Z, Zhao P, Huang L, Xu M, Yang Y, Chen X, Lu F, Zhang X, Wang H, Zhang S, Liu W, Jiang Z, Ma S, Chen R, Zhao C, Yang Z, Sui R, Zhu X. Whole-exome sequencing revealed HKDC1 as a candidate gene associated with autosomal-recessive retinitis pigmentosa. Hum Mol Genet 2018; 27:4157-4168. [PMID: 30085091 PMCID: PMC6240732 DOI: 10.1093/hmg/ddy281] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 07/02/2018] [Accepted: 07/23/2018] [Indexed: 01/04/2023] Open
Abstract
Retinitis pigmentosa (RP) is an inheritable retina degenerative disease leading to blindness. Despite the identification of 70 genes associated with RP, the genetic cause of ∼40% of RP patients remains to be elucidated. Whole-exome sequencing was applied on the probands of a RP cohort of 68 unsolved cases to identify candidate genetic mutations. A homozygous missense variant (c.173C > T, p.T58 M) was found in HKDC1 in two unrelated families presenting late-onset retinal degeneration. This variant affects highly conserved amino acid residue and is very rare in several databases and absent in 4000 ethnic-matched controls. Mutant HKDC1 protein partially lost hexokinase activity. Hkdc1 is expressed in the mouse retina and localized to photoreceptor inner segments. To elucidate the in vivo roles of Hkdc1 in the retina, we generated Hkdc1 knockout (KO) mouse models using CRISPR/Cas9 technique. Two independent alleles were identified and backcrossed to C57BL/6 J for 6 generations. Absence of HKDC1 expression in the Hkdc1 KO retina was confirmed by western blot and immunostaning using HKDC1 antibody. Hkdc1 KO mice exhibited reduced scotopic electroretinogram response and thinner outer nuclear layer, similar to some of the human patient phenotypes. Loss of Hkdc1 led to mislocalization of rhodopsin to the inner segments and cell bodies of rods in some regions in the retina. Taken together, our data demonstrated that HKDC1 is associated with autosomal recessively inherited RP.
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Affiliation(s)
- Lin Zhang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Center of Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Peiquan Zhao
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Lulin Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Mingchu Xu
- Department of Molecular and Human Genetics
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Yeming Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Xue Chen
- Department of Ophthalmology, Hospital of Nanjing Medical University, State Key Laboratory of Reproductive Medicine, Nanjing, China
| | - Fang Lu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Xiang Zhang
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hui Wang
- Institute of Life Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Shanshan Zhang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Wenjing Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Zhilin Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Laboratory Medicine, SichuanAcademy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Shi Ma
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Laboratory Medicine, SichuanAcademy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
| | - Rui Chen
- Department of Molecular and Human Genetics
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Chen Zhao
- Department of Ophthalmology, Hospital of Nanjing Medical University, State Key Laboratory of Reproductive Medicine, Nanjing, China
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Ophthalmology, Children’s Hospital of Zhengzhou, Zhengzhou, China
| | - Zhenglin Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Laboratory Medicine, SichuanAcademy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Hospital, Institute of Chengdu Biology Chengdu, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, Sichuan, China
- Institute of Laboratory Medicine, SichuanAcademy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Hospital, Institute of Chengdu Biology Chengdu, China
- Center of Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
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Megaw R, Hurd TW. Photoreceptor actin dysregulation in syndromic and non-syndromic retinitis pigmentosa. Biochem Soc Trans 2018; 46:1463-73. [PMID: 30464047 DOI: 10.1042/BST20180138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/26/2018] [Accepted: 10/12/2018] [Indexed: 01/11/2023]
Abstract
Retinitis pigmentosa (RP) is the leading cause of inherited blindness. RP is a genetically heterogeneous disorder, with more than 100 different causal genes identified in patients. Central to disease pathogenesis is the progressive loss of retinal photoreceptors. Photoreceptors are specialised sensory neurons that exhibit a complex and highly dynamic morphology. The highly polarised and elaborated architecture of photoreceptors requires precise regulation of numerous cytoskeletal elements. In recent years, significant work has been placed on investigating the role of microtubules (specifically, the acetylated microtubular axoneme of the photoreceptor connecting cilium) and their role in normal photoreceptor function. This has been driven by the emerging field of ciliopathies, human diseases arising from mutations in genes required for cilia formation or function, of which RP is a frequently reported phenotype. Recent studies have highlighted an intimate relationship between cilia and the actin cystoskeleton. This review will focus on the role of actin in photoreceptors, examining the connection between actin dysregulation in RP.
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Dharmat R, Eblimit A, Robichaux MA, Zhang Z, Nguyen TMT, Jung SY, He F, Jain A, Li Y, Qin J, Overbeek P, Roepman R, Mardon G, Wensel TG, Chen R. SPATA7 maintains a novel photoreceptor-specific zone in the distal connecting cilium. J Cell Biol 2018; 217:2851-2865. [PMID: 29899041 PMCID: PMC6080925 DOI: 10.1083/jcb.201712117] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/09/2018] [Accepted: 05/23/2018] [Indexed: 12/25/2022] Open
Abstract
Photoreceptor-specific ciliopathies often affect a structure that is considered functionally homologous to the ciliary transition zone (TZ) called the connecting cilium (CC). However, it is unclear how mutations in certain ciliary genes disrupt the photoreceptor CC without impacting the primary cilia systemically. By applying stochastic optical reconstruction microscopy technology in different genetic models, we show that the CC can be partitioned into two regions: the proximal CC (PCC), which is homologous to the TZ of primary cilia, and the distal CC (DCC), a photoreceptor-specific extension of the ciliary TZ. This specialized distal zone of the CC in photoreceptors is maintained by SPATA7, which interacts with other photoreceptor-specific ciliary proteins such as RPGR and RPGRIP1. The absence of Spata7 results in the mislocalization of DCC proteins without affecting the PCC protein complexes. This collapse results in destabilization of the axonemal microtubules, which consequently results in photoreceptor degeneration. These data provide a novel mechanism to explain how genetic disruption of ubiquitously present ciliary proteins exerts tissue-specific ciliopathy phenotypes.
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Affiliation(s)
- Rachayata Dharmat
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Aiden Eblimit
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Michael A Robichaux
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Zhixian Zhang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Thanh-Minh T Nguyen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Sung Yun Jung
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Feng He
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Antrix Jain
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Yumei Li
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Jun Qin
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Paul Overbeek
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Graeme Mardon
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Pathology and Immunology, Baylor College of Medicine, Houston, TX
| | - Theodore G Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Rui Chen
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
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Abstract
Precision medicine seeks to treat disease with molecular specificity. Advances in genome sequence analysis, gene delivery, and genome surgery have allowed clinician-scientists to treat genetic conditions at the level of their pathology. As a result, progress in treating retinal disease using genetic tools has advanced tremendously over the past several decades. Breakthroughs in gene delivery vectors, both viral and nonviral, have allowed the delivery of genetic payloads in preclinical models of retinal disorders and have paved the way for numerous successful clinical trials. Moreover, the adaptation of CRISPR-Cas systems for genome engineering have enabled the correction of both recessive and dominant pathogenic alleles, expanding the disease-modifying power of gene therapies. Here, we highlight the translational progress of gene therapy and genome editing of several retinal disorders, including RPE65-, CEP290-, and GUY2D-associated Leber congenital amaurosis, as well as choroideremia, achromatopsia, Mer tyrosine kinase- (MERTK-) and RPGR X-linked retinitis pigmentosa, Usher syndrome, neovascular age-related macular degeneration, X-linked retinoschisis, Stargardt disease, and Leber hereditary optic neuropathy.
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Affiliation(s)
- James E DiCarlo
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| | - Vinit B Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California, USA.,Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
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47
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Patnaik SR, Zhang X, Biswas L, Akhtar S, Zhou X, Kusuluri DK, Reilly J, May-Simera H, Chalmers S, McCarron JG, Shu X. RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry. Oncotarget 2018; 9:23183-23197. [PMID: 29796181 PMCID: PMC5955404 DOI: 10.18632/oncotarget.25259] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 04/07/2018] [Indexed: 11/25/2022] Open
Abstract
Ciliopathies are a group of genetically heterogeneous disorders, characterized by defects in cilia genesis or maintenance. Mutations in the RPGR gene and its interacting partners, RPGRIP1 and RPGRIP1L, cause ciliopathies, but the function of their proteins remains unclear. Here we show that knockdown (KD) of RPGR, RPGRIP1 or RPGRIP1L in hTERT-RPE1 cells results in abnormal actin cytoskeleton organization. The actin cytoskeleton rearrangement is regulated by the small GTPase RhoA via the planar cell polarity (PCP) pathway. RhoA activity was upregulated in the absence of RPGR, RPGRIP1 or RPGRIP1L proteins. In RPGR, RPGRIP1 or RPGRIP1L KD cells, we observed increased levels of DVl2 and DVl3 proteins, the core components of the PCP pathway, due to impaired proteasomal activity. RPGR, RPGRIP1 or RPGRIP1L KD cells treated with thapsigargin (TG), an inhibitor of sarcoendoplasmic reticulum Ca2+- ATPases, showed impaired store-operated Ca2+ entry (SOCE), which is mediated by STIM1 and Orai1 proteins. STIM1 was not localized to the ER-PM junction upon ER store depletion in RPGR, RPGRIP1 or RPGRIP1L KD cells. Our results demonstrate that the RPGR protein complex is required for regulating proteasomal activity and for modulating SOCE, which may contribute to the ciliopathy phenotype.
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Affiliation(s)
- Sarita Rani Patnaik
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
- Institute of Molecular Physiology, Johannes Gutenberg-Universität Mainz, D-55128 Mainz, Germany
| | - Xun Zhang
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Lincoln Biswas
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Saeed Akhtar
- Cornea Research Chair, Department of Optometry, King Saud University, Riyadh 11433, Kingdom of Saudi Arabia
| | - Xinzhi Zhou
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Deva Krupakar Kusuluri
- Institute of Molecular Physiology, Johannes Gutenberg-Universität Mainz, D-55128 Mainz, Germany
| | - James Reilly
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Helen May-Simera
- Institute of Molecular Physiology, Johannes Gutenberg-Universität Mainz, D-55128 Mainz, Germany
| | - Susan Chalmers
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, Scotland
| | - John G. McCarron
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, Scotland
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
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Zhang S, Li J, Li S, Yang Y, Yang M, Yang Z, Zhu X, Zhang L. Targeted next-generation sequencing reveals that a compound heterozygous mutation in phosphodiesterase 6a gene leads to retinitis pigmentosa in a Chinese family. Ophthalmic Genet 2018; 39:487-491. [PMID: 29693493 DOI: 10.1080/13816810.2018.1461912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Shanshan Zhang
- Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Jie Li
- Department of Ophthalmology, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Shujin Li
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
| | - Yeming Yang
- Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Mu Yang
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
| | - Zhenglin Yang
- Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Department of Ophthalmology, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
- Center of Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Xianjun Zhu
- Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Department of Ophthalmology, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
- Center of Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Lin Zhang
- Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Department of Ophthalmology, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Center of Information in Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
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49
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Deng WL, Gao ML, Lei XL, Lv JN, Zhao H, He KW, Xia XX, Li LY, Chen YC, Li YP, Pan D, Xue T, Jin ZB. Gene Correction Reverses Ciliopathy and Photoreceptor Loss in iPSC-Derived Retinal Organoids from Retinitis Pigmentosa Patients. Stem Cell Reports 2018. [PMID: 29526738 PMCID: PMC5998840 DOI: 10.1016/j.stemcr.2018.02.003] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Retinitis pigmentosa (RP) is an irreversible, inherited retinopathy in which early-onset nyctalopia is observed. Despite the genetic heterogeneity of RP, RPGR mutations are the most common causes of this disease. Here, we generated induced pluripotent stem cells (iPSCs) from three RP patients with different frameshift mutations in the RPGR gene, which were then differentiated into retinal pigment epithelium (RPE) cells and well-structured retinal organoids possessing electrophysiological properties. We observed significant defects in photoreceptor in terms of morphology, localization, transcriptional profiling, and electrophysiological activity. Furthermore, shorted cilium was found in patient iPSCs, RPE cells, and three-dimensional retinal organoids. CRISPR-Cas9-mediated correction of RPGR mutation rescued photoreceptor structure and electrophysiological property, reversed the observed ciliopathy, and restored gene expression to a level in accordance with that in the control using transcriptome-based analysis. This study recapitulated the pathogenesis of RPGR using patient-specific organoids and achieved targeted gene therapy of RPGR mutations in a dish as proof-of-concept evidence. HiPSC-derived 3D retinae with outer segments and electrophysiological properties RPGR mutation results in diseased photoreceptor in patient iPSC-derived 3D retinae Mutation correction rescues defects in photoreceptor morphology and electrophysiology Ciliogenesis defects appear in RPGR patient-specific iPSCs, iPSC-RPE, and 3D retinae
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Affiliation(s)
- Wen-Li Deng
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Mei-Ling Gao
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Xin-Lan Lei
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Ji-Neng Lv
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Huan Zhao
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Brain Function and Disease, Neurodegenerative Disorder Research Center, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Kai-Wen He
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Xi-Xi Xia
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Ling-Yun Li
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Brain Function and Disease, Neurodegenerative Disorder Research Center, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Yu-Chen Chen
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Yan-Ping Li
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Deng Pan
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China
| | - Tian Xue
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Brain Function and Disease, Neurodegenerative Disorder Research Center, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Zi-Bing Jin
- Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Wenzhou 325027, China.
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50
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Rao KN, Zhang W, Li L, Anand M, Khanna H. Prenylated retinal ciliopathy protein RPGR interacts with PDE6δ and regulates ciliary localization of Joubert syndrome-associated protein INPP5E. Hum Mol Genet 2018; 25:4533-4545. [PMID: 28172980 DOI: 10.1093/hmg/ddw281] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/24/2016] [Accepted: 08/19/2016] [Indexed: 12/11/2022] Open
Abstract
Ciliary trafficking defects underlie the pathogenesis of severe human ciliopathies, including Joubert Syndrome (JBTS), Bardet-Biedl Syndrome, and some forms of retinitis pigmentosa (RP). Mutations in the ciliary protein RPGR (retinitis pigmentosa GTPase regulator) are common causes of RP-associated photoreceptor degeneration worldwide. While previous work has suggested that the localization of RPGR to cilia is critical to its functions, the mechanism by which RPGR and its associated cargo are trafficked to the cilia is unclear. Using proteomic and biochemical approaches, we show that RPGR interacts with two JBTS-associated ciliary proteins: PDE6δ (delta subunit of phosphodiesterase; a prenyl-binding protein) and INPP5E (inositol polyphosphate-5-phosphatase 5E). We find that PDE6δ binds selectively to the C-terminus of RPGR and that this interaction is critical for RPGR’s localization to cilia. Furthermore, we show that INPP5E associates with the N-terminus of RPGR and trafficking of INPP5E to cilia is dependent upon the ciliary localization of RPGR. These results implicate prenylation of RPGR as a critical modification for its localization to cilia and, in turn suggest that trafficking of INPP5E to cilia depends upon the interaction of RPGR with PDE6δ. Finally, our results implicate INPP5E, a novel RPGR-interacting protein, in the pathogenesis of RPGR-associated ciliopathies.
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Affiliation(s)
- Kollu N Rao
- Department of Ophthalmology, Horae Gene Therapy Center, UMASS Medical School, Worcester, MA, USA
| | - Wei Zhang
- Department of Ophthalmology, Horae Gene Therapy Center, UMASS Medical School, Worcester, MA, USA
| | - Linjing Li
- Department of Ophthalmology, Horae Gene Therapy Center, UMASS Medical School, Worcester, MA, USA
| | - Manisha Anand
- Department of Ophthalmology, Horae Gene Therapy Center, UMASS Medical School, Worcester, MA, USA
| | - Hemant Khanna
- Department of Ophthalmology, Horae Gene Therapy Center, UMASS Medical School, Worcester, MA, USA
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