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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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Nonarath HJT, Simpson SL, Slobodianuk TL, Collery RF, Dinculescu A, Link BA. The USH3A causative gene clarin1 functions in Müller glia to maintain retinal photoreceptors. bioRxiv 2024:2024.02.29.582878. [PMID: 38464015 PMCID: PMC10925332 DOI: 10.1101/2024.02.29.582878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Mutations in CLRN1 cause Usher syndrome type IIIA (USH3A), an autosomal recessive disorder characterized by hearing and vision loss, and often accompanied by vestibular balance issues. The identity of the cell types responsible for the pathology and mechanisms leading to vision loss in USH3A remains elusive. To address this, we employed CRISPR/Cas9 technology to delete a large region in the coding and untranslated (UTR) region of zebrafish clrn1. Retina of clrn1 mutant larvae exhibited sensitivity to cell stress, along with age-dependent loss of function and degeneration in the photoreceptor layer. Investigation revealed disorganization in the outer retina in clrn1 mutants, including actin-based structures of the Müller glia and photoreceptor cells. To assess cell-specific contributions to USH3A pathology, we specifically re-expressed clrn1 in either Müller glia or photoreceptor cells. Müller glia re-expression of clrn1 prevented the elevated cell death observed in larval clrn1 mutant zebrafish exposed to high-intensity light. Notably, the degree of phenotypic rescue correlated with the level of Clrn1 re-expression. Surprisingly, high levels of Clrn1 expression enhanced cell death in both wild-type and clrn1 mutant animals. However, rod- or cone-specific Clrn1 re-expression did not rescue the extent of cell death. Taken together, our findings underscore three crucial insights. First, clrn1 mutant zebrafish exhibit key pathological features of USH3A; second, Clrn1 within Müller glia plays a pivotal role in photoreceptor maintenance, with its expression requiring controlled regulation; third, the reliance of photoreceptors on Müller glia suggests a structural support mechanism, possibly through direct interactions between Müller glia and photoreceptors mediated in part by Clrn1 protein.
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Affiliation(s)
- Hannah J. T. Nonarath
- Department Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Samantha L. Simpson
- Department of Ophthalmology and Vision Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Tricia L. Slobodianuk
- Department Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Ross F. Collery
- Department of Ophthalmology and Vision Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Astra Dinculescu
- Department of Ophthalmology, University of Florida, Gainesville, Florida 32611
| | - Brian A. Link
- Department Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
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Jiang Q, Liang X, Ye T, Zhang Y, Lou B. Metabonomics and Transcriptomics Analyses Reveal the Development Process of the Auditory System in the Embryonic Development Period of the Small Yellow Croaker under Background Noise. Int J Mol Sci 2024; 25:1954. [PMID: 38396633 PMCID: PMC10888356 DOI: 10.3390/ijms25041954] [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: 12/07/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Underwater noise pollution has become a potential threat to aquatic animals in the natural environment. The main causes of such pollution are frequent human activities creating underwater environmental noise, including commercial shipping, offshore energy platforms, scientific exploration activities, etc. However, in aquaculture environments, underwater noise pollution has also become an unavoidable problem due to background noise created by aquaculture equipment. Some research has shown that certain fish show adaptability to noise over a period of time. This could be due to fish's special auditory organ, i.e., their "inner ear"; meanwhile, otoliths and sensory hair cells are the important components of the inner ear and are also essential for the function of the auditory system. Recently, research in respect of underwater noise pollution has mainly focused on adult fish, and there is a lack of the research on the effects of underwater noise pollution on the development process of the auditory system in the embryonic development period. Thus, in this study, we collected embryo-larval samples of the small yellow croaker (Larimichthys polyactis) in four important stages of otic vesicle development through artificial breeding. Then, we used metabonomics and transcriptomics analyses to reveal the development process of the auditory system in the embryonic development period under background noise (indoor and underwater environment sound). Finally, we identified 4026 differentially expressed genes (DEGs) and 672 differential metabolites (DMs), including 37 DEGs associated with the auditory system, and many differences mainly existed in the neurula stage (20 h of post-fertilization/20 HPF). We also inferred the regulatory mode and process of some important DEGs (Dnmt1, CPS1, and endothelin-1) in the early development of the auditory system. In conclusion, we suggest that the auditory system development of L. polyactis begins at least in the neurula stage or earlier; the other three stages (tail bud stage, caudal fin fold stage, and heart pulsation stage, 28-35 HPF) mark the rapid development period. We speculate that the effect of underwater noise pollution on the embryo-larval stage probably begins even earlier.
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Affiliation(s)
| | | | | | | | - Bao Lou
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Hydrobiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310000, China; (Q.J.); (X.L.); (T.Y.); (Y.Z.)
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4
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Nguyen VP, Hu J, Zhe J, Chen EY, Yang D, Paulus YM. Multimodal photoacoustic microscopy, optical coherence tomography, and fluorescence imaging of USH2A knockout rabbits. Sci Rep 2023; 13:22071. [PMID: 38086867 PMCID: PMC10716268 DOI: 10.1038/s41598-023-48872-1] [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: 07/17/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Usher syndrome type 2A (USH2A) is a genetic disorder characterized by retinal degeneration and hearing loss. To better understand the pathogenesis and progression of this syndrome, animal models such as USH2A knockout (USH2AKO) rabbits have been developed. In this study, we employed multimodal imaging techniques, including photoacoustic microscopy (PAM), optical coherence tomography (OCT), fundus autofluorescence (FAF), fluorescein angiography (FA), and indocyanine green angiography (ICGA) imaging to evaluate the retinal changes in the USH2AKO rabbit model. Twelve New Zealand White rabbits including USH2AKO and wild type (WT) were used for the experiments. Multimodal imaging was implemented at different time points over a period of 12 months to visualize the progression of retinal changes in USH2AKO rabbits. The results demonstrate that ellipsoid zone (EZ) disruption and degeneration, key features of Usher syndrome, began at the age of 4 months old and persisted up to 12 months. The EZ degeneration areas were clearly observed on the FAF and OCT images. The FAF images revealed retinal pigment epithelium (RPE) degeneration, confirming the presence of the disease phenotype in the USH2AKO rabbits. In addition, PAM images provided high-resolution and high image contrast of the optic nerve and the retinal microvasculature, including retinal vessels, choroidal vessels, and capillaries in three-dimensions. The quantification of EZ fluorescent intensity using FAF and EZ thickness using OCT provided comprehensive quantitative data on the progression of degenerative changes over time. This multimodal imaging approach allowed for a comprehensive and non-invasive assessment of retinal structure, microvasculature, and degenerative changes in the USH2AKO rabbit model. The combination of PAM, OCT, and fluorescent imaging facilitated longitudinal monitoring of disease progression and provided valuable insights into the pathophysiology of USH2A syndrome. These findings contribute to the understanding of USH2A syndrome and may have implications for the development of diagnostic and therapeutic strategies for affected individuals. The multimodal imaging techniques employed in this study offer a promising platform for preclinical evaluation of potential treatments and may pave the way for future clinical applications in patients with Usher syndrome.
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Affiliation(s)
- Van Phuc Nguyen
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Justin Hu
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Josh Zhe
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Eugene Y Chen
- Department of Internal Medicine, Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan, 2800 Plymouth Rd NCRC B26-355S, Ann Arbor, MI, 48109-2800, USA
| | - Dongshan Yang
- Department of Internal Medicine, Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan, 2800 Plymouth Rd NCRC B26-355S, Ann Arbor, MI, 48109-2800, USA.
| | - Yannis M Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA.
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48105, USA.
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Sanjurjo-Soriano C, Jimenez-Medina C, Erkilic N, Cappellino L, Lefevre A, Nagel-Wolfrum K, Wolfrum U, Van Wijk E, Roux AF, Meunier I, Kalatzis V. USH2A variants causing retinitis pigmentosa or Usher syndrome provoke differential retinal phenotypes in disease-specific organoids. HGG Adv 2023; 4:100229. [PMID: 37654703 PMCID: PMC10465966 DOI: 10.1016/j.xhgg.2023.100229] [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: 06/05/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023] Open
Abstract
There is an emblematic clinical and genetic heterogeneity associated with inherited retinal diseases (IRDs). The most common form is retinitis pigmentosa (RP), a rod-cone dystrophy caused by pathogenic variants in over 80 different genes. Further complexifying diagnosis, different variants in individual RP genes can also alter the clinical phenotype. USH2A is the most prevalent gene for autosomal-recessive RP and one of the most challenging because of its large size and, hence, large number of variants. Moreover, USH2A variants give rise to non-syndromic and syndromic RP, known as Usher syndrome (USH) type 2, which is associated with vision and hearing loss. The lack of a clear genotype-phenotype correlation or prognostic models renders diagnosis highly challenging. We report here a long-awaited differential non-syndromic RP and USH phenotype in three human disease-specific models: fibroblasts, induced pluripotent stem cells (iPSCs), and mature iPSC-derived retinal organoids. Moreover, we identified distinct retinal phenotypes in organoids from multiple RP and USH individuals, which were validated by isogenic-corrected controls. Non-syndromic RP organoids showed compromised photoreceptor differentiation, whereas USH organoids showed a striking and unexpected cone phenotype. Furthermore, complementary clinical investigations identified macular atrophy in a high proportion of USH compared with RP individuals, further validating our observations that USH2A variants differentially affect cones. Overall, identification of distinct non-syndromic RP and USH phenotypes in multiple models provides valuable and robust readouts for testing the pathogenicity of USH2A variants as well as the efficacy of therapeutic approaches in complementary cell types.
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Affiliation(s)
- Carla Sanjurjo-Soriano
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Carla Jimenez-Medina
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Nejla Erkilic
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Luisina Cappellino
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Arnaud Lefevre
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, CHU, Montpellier, France
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Erwin Van Wijk
- Department of Otorhinolaryngology, Hearing, & Genes, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition, and Behavior, Nijmegen, the Netherlands
| | - Anne-Françoise Roux
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
- Molecular Genetics Laboratory, University of Montpellier, CHU, Montpellier, France
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, CHU, Montpellier, France
| | - Vasiliki Kalatzis
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
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6
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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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7
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Crane R, Tebbe L, Mwoyosvi ML, Al-Ubaidi MR, Naash MI. Expression of the human usherin c.2299delG mutation leads to early-onset auditory loss and stereocilia disorganization. Commun Biol 2023; 6:933. [PMID: 37700068 PMCID: PMC10497539 DOI: 10.1038/s42003-023-05296-x] [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: 04/25/2023] [Accepted: 08/29/2023] [Indexed: 09/14/2023] Open
Abstract
Usher syndrome (USH) is the leading cause of combined deafness and blindness, with USH2A being the most prevalent form. The mechanisms responsible for this debilitating sensory impairment remain unclear. This study focuses on characterizing the auditory phenotype in a mouse model expressing the c.2290delG mutation in usherin equivalent to human frameshift mutation c.2299delG. Previously we described how this model reproduces patient's retinal phenotypes. Here, we present the cochlear phenotype, showing that the mutant usherin, is expressed during early postnatal stages. The c.2290delG mutation results in a truncated protein that is mislocalized within the cell body of the hair cells. The knock-in model also exhibits congenital hearing loss that remains consistent throughout the animal's lifespan. Structurally, the stereocilia bundles, particularly in regions associated with functional hearing loss, are disorganized. Our findings shed light on the role of usherin in maintaining structural support, specifically in longer inner hair cell stereocilia, during development, which is crucial for proper bundle organization and hair cell function. Overall, we present a genetic mouse model with cochlear defects associated with the c.2290delG mutation, providing insights into the etiology of hearing loss and offering potential avenues for the development of effective therapeutic treatments for USH2A patients.
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Affiliation(s)
- Ryan Crane
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - 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
| | - 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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8
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Toms M, Toualbi L, Almeida PV, Harbottle R, Moosajee M. Successful large gene augmentation of USH2A with non-viral episomal vectors. Mol Ther 2023; 31:2755-2766. [PMID: 37337429 PMCID: PMC10491995 DOI: 10.1016/j.ymthe.2023.06.012] [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: 01/05/2023] [Revised: 05/09/2023] [Accepted: 06/14/2023] [Indexed: 06/21/2023] Open
Abstract
USH2A mutations are a common cause of autosomal recessive retinitis pigmentosa (RP) and Usher syndrome, for which there are currently no approved treatments. Gene augmentation is a valuable therapeutic strategy for treating many inherited retinal diseases; however, conventional adeno-associated virus (AAV) gene therapy cannot accommodate cDNAs exceeding 4.7 kb, such as the 15.6-kb-long USH2A coding sequence. In the present study, we adopted an alternative strategy to successfully generate scaffold/matrix attachment region (S/MAR) DNA plasmid vectors containing the full-length human USH2A coding sequence, a GFP reporter gene, and a ubiquitous promoter (CMV or CAG), reaching a size of approximately 23 kb. We assessed the vectors in transfected HEK293 cells and USH2A patient-derived dermal fibroblasts in addition to ush2au507 zebrafish microinjected with the vector at the one-cell stage. pS/MAR-USH2A vectors drove persistent transgene expression in patient fibroblasts with restoration of usherin. Twelve months of GFP expression was detected in the photoreceptor cells, with rescue of Usher 2 complex localization in the photoreceptors of ush2au507 zebrafish retinas injected with pS/MAR-USH2A. To our knowledge, this is the first reported vector that can be used to express full-length usherin with functional rescue. S/MAR DNA vectors have shown promise as a novel non-viral retinal gene therapy, warranting further translational development.
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Affiliation(s)
- Maria Toms
- Development, Ageing, and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK; Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK
| | - Lyes Toualbi
- Development, Ageing, and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK; Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK
| | - Patrick V Almeida
- DNA Vector Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Richard Harbottle
- DNA Vector Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Mariya Moosajee
- Development, Ageing, and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK; Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK; Department of Genetics, Moorfields Eye Hospital, NHS Foundation Trust, London EC1V 2PD, UK.
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Schellens RT, Broekman S, Peters T, Graave P, Malinar L, Venselaar H, Kremer H, De Vrieze E, Van Wijk E. A protein domain-oriented approach to expand the opportunities of therapeutic exon skipping for USH2A-associated retinitis pigmentosa. Mol Ther Nucleic Acids 2023; 32:980-994. [PMID: 37313440 PMCID: PMC10258241 DOI: 10.1016/j.omtn.2023.05.020] [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: 11/18/2022] [Accepted: 05/17/2023] [Indexed: 06/15/2023]
Abstract
Loss-of-function mutations in USH2A are among the most common causes of syndromic and non-syndromic retinitis pigmentosa (RP). We previously presented skipping of USH2A exon 13 as a promising treatment paradigm for USH2A-associated RP. However, RP-associated mutations are often private, and evenly distributed along the USH2A gene. In order to broaden the group of patients that could benefit from therapeutic exon skipping strategies, we expanded our approach to other USH2A exons in which unique loss-of-function mutations have been reported by implementing a protein domain-oriented dual exon skipping strategy. We first generated zebrafish mutants carrying a genomic deletion of the orthologous exons of the frequently mutated human USH2A exons 30-31 or 39-40 using CRISPR-Cas9. Excision of these in-frame combinations of exons restored usherin expression in the zebrafish retina and rescued the photopigment mislocalization typically observed in ush2a mutants. To translate these findings into a future treatment in humans, we employed in vitro assays to identify and validate antisense oligonucleotides (ASOs) with a high potency for sequence-specific dual exon skipping. Together, the in vitro and in vivo data demonstrate protein domain-oriented ASO-induced dual exon skipping to be a highly promising treatment option for RP caused by mutations in USH2A.
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Affiliation(s)
- Renske T.W. Schellens
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, 6525GA Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, 6500 GL Nijmegen, the Netherlands
| | - Sanne Broekman
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, 6525GA Nijmegen, the Netherlands
| | - Theo Peters
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, 6525GA Nijmegen, the Netherlands
| | - Pam Graave
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Lucija Malinar
- Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Hanka Venselaar
- Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Hannie Kremer
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, 6525GA Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, 6500 GL Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Erik De Vrieze
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, 6525GA Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, 6500 GL Nijmegen, the Netherlands
| | - Erwin Van Wijk
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, 6525GA Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, 6500 GL Nijmegen, the Netherlands
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Stemerdink M, Broekman S, Peters T, Kremer H, de Vrieze E, van Wijk E. Generation and Characterization of a Zebrafish Model for ADGRV1-Associated Retinal Dysfunction Using CRISPR/Cas9 Genome Editing Technology. Cells 2023; 12:1598. [PMID: 37371069 DOI: 10.3390/cells12121598] [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: 03/21/2023] [Revised: 05/26/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Worldwide, around 40,000 people progressively lose their eyesight as a consequence of retinitis pigmentosa (RP) caused by pathogenic variants in the ADGRV1 gene, for which currently no treatment options exist. A model organism that mimics the human phenotype is essential to unravel the exact pathophysiological mechanism underlying ADGRV1-associated RP, and to evaluate future therapeutic strategies. The introduction of CRISPR/Cas-based genome editing technologies significantly improved the possibilities of generating mutant models in a time- and cost-effective manner. Zebrafish have been recognized as a suitable model to study Usher syndrome-associated retinal dysfunction. Using CRISPR/Cas9 technology we introduced a 4bp deletion in adgrv1 exon 9 (adgrv1rmc22). Immunohistochemical analysis showed that Adgrv1 was absent from the region of the photoreceptor connecting cilium in the adgrv1rmc22 zebrafish retina. Here, the absence of Adgrv1 also resulted in reduced levels of the USH2 complex members usherin and Whrnb, suggesting that Adgrv1 interacts with usherin and Whrnb in zebrafish photoreceptors. When comparing adgrv1rmc22 zebrafish with wild-type controls, we furthermore observed increased levels of aberrantly localized rhodopsin in the photoreceptor cell body, and decreased electroretinogram (ERG) B-wave amplitudes which indicate that the absence of Adgrv1 results in impaired retinal function. Based on these findings we present the adgrv1rmc22 zebrafish as the first ADGRV1 mutant model that displays an early retinal dysfunction. Moreover, the observed phenotypic changes can be used as quantifiable outcome measures when evaluating the efficacy of future novel therapeutic strategies for ADGRV1-associated RP.
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Affiliation(s)
- Merel Stemerdink
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Sanne Broekman
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Theo Peters
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Hannie Kremer
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
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11
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Abu-Diab A, Gopalakrishnan P, Matsevich C, de Jong M, Obolensky A, Khalaileh A, Salameh M, Ejzenberg A, Gross M, Banin E, Sharon D, Khateb S. Homozygous Knockout of Cep250 Leads to a Relatively Late-Onset Retinal Degeneration and Sensorineural Hearing Loss in Mice. Transl Vis Sci Technol 2023; 12:3. [PMID: 36857066 PMCID: PMC9987170 DOI: 10.1167/tvst.12.3.3] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023] Open
Abstract
Purpose Usher syndrome (USH) is the most common syndromic inherited retinal disease, causing retinitis pigmentosa and sensorineural hearing loss. We reported previously that a nonsense mutation in the centrosome-associated protein CEP250 gene (encoding C-Nap1) causes atypical USH in patients of Iranian Jewish origin. To better characterize CEP250, we aimed to generate and study a knockout (KO) mouse model for Cep250. Methods Mice heterozygous for a "knockout-first" Cep250 construct were generated and bred with Cre recombinase mice to generate the null allele and produce homozygous Cep250 KO mice. Retinal function was evaluated by full-field electroretinography (ffERG) at variable ages, and retinal structure changes were examined using histological analysis. Hearing thresholds were detected using auditory brainstem response (ABR) at the age of 20 months. Results The Cep250 KO mouse model was generated by activating a construct harboring a deletion of exons 6 and 7. At 6 months, the ffERG was normal, but it decreased gradually with age. For both photopic and scotopic ffERG responses, very low amplitudes were evident at 20 months. Histological analysis confirmed late-onset retinal degeneration. ABR tests illustrated that hearing threshold significantly increased at the age of 20 months. Conclusions Although most USH animal models have normal retinal function and structure, the Cep250 KO mouse model shows both retinal degeneration and hearing loss with a relatively late age of onset. This model may shed more light on CEP250-associated retinal and hearing deficits and represents an efficient platform for the development of treatment modalities for USH. Translational Relevance Our study demonstrates better understanding of Cep250-associated retinal and hearing disease in a mouse model and may help in developing more efficient gene therapy modalities.
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Affiliation(s)
- Alaa Abu-Diab
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Prakadeeswari Gopalakrishnan
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Chen Matsevich
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Marije de Jong
- Department of Otolaryngology, Head and Neck Surgery, Hadassah Hebrew-University Medical Center, Jerusalem, Israel
| | - Alexey Obolensky
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ayat Khalaileh
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Manar Salameh
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ayala Ejzenberg
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Menachem Gross
- Department of Otolaryngology, Head and Neck Surgery, Hadassah Hebrew-University Medical Center, Jerusalem, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Samer Khateb
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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12
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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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13
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Huang Y, Yuan L, He G, Cao Y, Deng X, Deng H. Novel compound heterozygous variants in the USH2A gene associated with autosomal recessive retinitis pigmentosa without hearing loss. Front Cell Dev Biol 2023; 11:1129862. [PMID: 36875754 PMCID: PMC9974670 DOI: 10.3389/fcell.2023.1129862] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/25/2023] [Indexed: 02/17/2023] Open
Abstract
Background: Retinitis pigmentosa (RP) is a group of progressive inherited retinal dystrophies characterized by the primary degeneration of rod photoreceptors and the subsequent loss of cone photoreceptors because of cell death. It is caused by different mechanisms, including inflammation, apoptosis, necroptosis, pyroptosis, and autophagy. Variants in the usherin gene (USH2A) have been reported in autosomal recessive RP with or without hearing loss. In the present study, we aimed to identify causative variants in a Han-Chinese pedigree with autosomal recessive RP. Methods: A six-member, three-generation Han-Chinese family with autosomal recessive RP was recruited. A full clinical examination, whole exome sequencing, and Sanger sequencing, as well as co-segregation analysis were performed. Results: Three heterozygous variants in the USH2A gene, c.3304C>T (p.Q1102*), c.4745T>C (p.L1582P), and c.14740G>A (p.E4914K), were identified in the proband, which were inherited from parents and transmitted to the daughters. Bioinformatics analysis supported the pathogenicity of the c.3304C>T (p.Q1102*) and c.4745T>C (p.L1582P) variants. Conclusions: Novel compound heterozygous variants in the USH2A gene, c.3304C>T (p.Q1102*) and c.4745T>C (p.L1582P), were identified as the genetic causes of autosomal recessive RP. The findings may enhance the current knowledge of the pathogenesis of USH2A-associated phenotypes, expand the spectrum of the USH2A gene variants, and contribute to improved genetic counseling, prenatal diagnosis, and disease management.
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Affiliation(s)
- Yanxia Huang
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China
| | - Lamei Yuan
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China
| | - Guiyun He
- Department of Ophthalmology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Yanna Cao
- Department of Ophthalmology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China
| | - Hao Deng
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
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14
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Barrett LM, Meighan PC, Mitchell DM, Varnum MD, Stenkamp DL. Assessing Rewiring of the Retinal Circuitry by Electroretinogram (ERG) After Inner Retinal Lesion in Adult Zebrafish. Methods Mol Biol 2023; 2636:421-435. [PMID: 36881314 DOI: 10.1007/978-1-0716-3012-9_23] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Adult zebrafish respond to retinal injury with a regenerative response that replaces damaged neurons with Müller glia-derived regenerated neurons. The regenerated neurons are functional, appear to make appropriate synaptic connections, and support visually mediated reflexes and more complex behaviors. Curiously, the electrophysiology of damaged, regenerating, and regenerated zebrafish retina has only recently been examined. In our previous work, we demonstrated that electroretinogram (ERG) recordings of damaged zebrafish retina correlate with the extent of the inflicted damage and that the regenerated retina at 80 days post-injury exhibited ERG waveforms consistent with functional visual processing. In this paper we describe the procedure for obtaining and analyzing ERG recordings from adult zebrafish previously subjected to widespread lesions that destroy inner retinal neurons and engage a regenerative response that restores retinal function, in particular the synaptic connections between photoreceptor axon terminals and the dendritic trees of retinal bipolar neurons.
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Affiliation(s)
- Lindsey M Barrett
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Peter C Meighan
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Diana M Mitchell
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Michael D Varnum
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Deborah L Stenkamp
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA.
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15
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Su T, Liang L, Zhang L, Wang J, Chen L, Su C, Cao J, Yu Q, Deng S, Chan HF, Tang S, Guo Y, Chen J. Retinal organoids and microfluidic chip-based approaches to explore the retinitis pigmentosa with USH2A mutations. Front Bioeng Biotechnol 2022; 10:939774. [PMID: 36185441 PMCID: PMC9524156 DOI: 10.3389/fbioe.2022.939774] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [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: 05/09/2022] [Accepted: 08/23/2022] [Indexed: 11/19/2022] Open
Abstract
Retinitis pigmentosa (RP) is a leading cause of vision impairment and blindness worldwide, with limited medical treatment options. USH2A mutations are one of the most common causes of non-syndromic RP. In this study, we developed retinal organoids (ROs) and retinal pigment epithelium (RPE) cells from induced pluripotent stem cells (iPSCs) of RP patient to establish a sustainable in vitro RP disease model. RT-qPCR, western blot, and immunofluorescent staining assessments showed that USH2A mutations induced apoptosis of iPSCs and ROs, and deficiency of the extracellular matrix (ECM) components. Transcriptomics and proteomics findings suggested that abnormal ECM-receptor interactions could result in apoptosis of ROs with USH2A mutations via the PI3K-Akt pathway. To optimize the culture conditions of ROs, we fabricated a microfluidic chip to co-culture the ROs with RPE cells. Our results showed that this perfusion system could efficiently improve the survival rate of ROs. Further, ECM components such as laminin and collagen IV of ROs in the RP group were upregulated compared with those maintained in static culture. These findings illustrate the potential of microfluidic chip combined with ROs technology in disease modelling for RP.
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Affiliation(s)
- Ting Su
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Liying Liang
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Lan Zhang
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Jianing Wang
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China
| | - Luyin Chen
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China
| | - Caiying Su
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Jixing Cao
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Quan Yu
- Centric Laboratory, Medical College, Jinan University, Guangzhou, China
| | - Shuai Deng
- Institute for Tissue Engineering and Regenerative Medicine, Chinese University of Hong Kong, Hong Kong, China
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Hon Fai Chan
- Institute for Tissue Engineering and Regenerative Medicine, Chinese University of Hong Kong, Hong Kong, China
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | | | - Yonglong Guo
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- *Correspondence: Jiansu Chen, ; Yonglong Guo,
| | - Jiansu Chen
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China
- Aier Eye Institute, Changsha, China
- Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
- *Correspondence: Jiansu Chen, ; Yonglong Guo,
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16
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Kamel SM, Broekman S, Tessadori F, van Wijk E, Bakkers J. The zebrafish cohesin protein Sgo1 is required for cardiac function and eye development. Dev Dyn 2022; 251:1357-1367. [PMID: 35275424 PMCID: PMC9545960 DOI: 10.1002/dvdy.468] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/02/2022] [Accepted: 03/05/2022] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Cohesinopathies is a term that refers to/covers rare genetic diseases caused by mutations in the cohesin complex proteins. The cohesin complex is a multiprotein complex that facilitates different aspects of cell division, gene transcription, DNA damage repair, and chromosome architecture. Shugoshin proteins prevent the cohesin complex from premature dissociation from chromatids during cell division. Patients with a homozygous missense mutation in SGO1, which encodes for Shugoshin1, have problems with normal pacing of the heart and gut. RESULTS To study the role of shugoshin during embryo development, we mutated the zebrafish sgo1 gene. Homozygous sgo1 mutant embryos display various phenotypes related to different organs, including a reduced heart rate accompanied by reduced cardiac function. In addition, sgo1 mutants are vision-impaired as a consequence of structurally defective and partially non-functional photoreceptor cells. Furthermore, the sgo1 mutants display reduced food intake and early lethality. CONCLUSION We have generated a zebrafish model of Sgo1 that showed its importance during organ development and function.
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Affiliation(s)
- Sarah M. Kamel
- Hubrecht Institute‐KNAW, University Medical Centre UtrechtUtrechtThe Netherlands
| | - Sanne Broekman
- Department of OtorhinolaryngologyRadboud University Medical CenterNijmegenThe Netherlands
- Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Federico Tessadori
- Hubrecht Institute‐KNAW, University Medical Centre UtrechtUtrechtThe Netherlands
| | - Erwin van Wijk
- Department of OtorhinolaryngologyRadboud University Medical CenterNijmegenThe Netherlands
- Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Jeroen Bakkers
- Hubrecht Institute‐KNAW, University Medical Centre UtrechtUtrechtThe Netherlands
- Department of Medical Physiology, Division of Heart & LungsUniversity Medical Center UtrechtUtrechtThe Netherlands
- Department of Pediatric Cardiology, Division of PediatricsUniversity Medical Center UtrechtUtrechtThe Netherlands
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17
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Noel NCL, Allison WT, MacDonald IM, Hocking JC. Zebrafish and inherited photoreceptor disease: Models and insights. Prog Retin Eye Res 2022;:101096. [PMID: 35811244 DOI: 10.1016/j.preteyeres.2022.101096] [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] [Received: 04/23/2022] [Revised: 06/20/2022] [Accepted: 06/23/2022] [Indexed: 11/21/2022]
Abstract
Photoreceptor dysfunctions and degenerative diseases are significant causes of vision loss in patients, with few effective treatments available. Targeted interventions to prevent or reverse photoreceptor-related vision loss are not possible without a thorough understanding of the underlying mechanism leading to disease, which is exceedingly difficult to accomplish in the human system. Cone diseases are particularly challenging to model, as some popular genetically modifiable model animals are nocturnal with a rod-dominant visual system and cones that have dissimilarities to human cones. As a result, cone diseases, which affect visual acuity, colour perception, and central vision in patients, are generally poorly understood in terms of pathology and mechanism. Zebrafish (Danio rerio) provide the opportunity to model photoreceptor diseases in a diurnal vertebrate with a cone-rich retina which develops many macular degeneration-like pathologies. Zebrafish undergo external development, allowing early-onset retinal diseases to be detected and studied, and many ophthalmic tools are available for zebrafish visual assessment during development and adulthood. There are numerous zebrafish models of photoreceptor disease, spanning the various types of photoreceptor disease (developmental, rod, cone, and mixed photoreceptor diseases) and genetic/molecular cause. In this review, we explore the features of zebrafish that make them uniquely poised to model cone diseases, summarize the established zebrafish models of inherited photoreceptor disease, and discuss how disease in these models compares to the human presentation, where applicable. Further, we highlight the contributions of these zebrafish models to our understanding of photoreceptor biology and disease, and discuss future directions for utilising and investigating these diverse models.
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18
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Zaw K, Carvalho LS, Aung-Htut MT, Fletcher S, Wilton SD, Chen FK, McLenachan S. Pathogenesis and Treatment of Usher Syndrome Type IIA. Asia Pac J Ophthalmol (Phila) 2022; 11:369-379. [PMID: 36041150 DOI: 10.1097/apo.0000000000000546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/27/2022] [Indexed: 12/16/2022] Open
Abstract
Usher syndrome (USH) is the most common form of deaf-blindness, with an estimated prevalence of 4.4 to 16.6 per 100,000 people worldwide. The most common form of USH is type IIA (USH2A), which is caused by homozygous or compound heterozygous mutations in the USH2A gene and accounts for around half of all USH cases. USH2A patients show moderate to severe hearing loss from birth, with diagnosis of retinitis pigmentosa in the second decade of life and variable vestibular involvement. Although hearing aids or cochlear implants can provide some mitigation of hearing deficits, there are currently no treatments aimed at preventing or restoring vision loss in USH2A patients. In this review, we first provide an overview of the molecular biology of the USH2A gene and its protein isoforms, which include a transmembrane protein (TM usherin) and an extracellular protein (EC usherin). The role of these proteins in the inner ear and retina and their impact on the pathogenesis of USH2A is discussed. We review animal cell-derived and patient cell-derived models currently used in USH2A research and conclude with an overview of potential treatment strategies currently in preclinical development and clinical trials.
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Affiliation(s)
- Khine Zaw
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Livia S Carvalho
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
| | - May T Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Fred K Chen
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia
| | - Samuel McLenachan
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
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Reurink J, de Vrieze E, Li CHZ, van Berkel E, Broekman S, Aben M, Peters T, Oostrik J, Neveling K, Venselaar H, Ramos MG, Gilissen C, Astuti GDN, Galbany JC, van Lith-verhoeven JJC, Ockeloen CW, Haer-wigman L, Hoyng CB, Cremers FPM, Kremer H, Roosing S, van Wijk E. Scrutinizing pathogenicity of the USH2A c.2276 G > T; p.(Cys759Phe) variant. NPJ Genom Med 2022; 7. [PMID: 35672333 PMCID: PMC9174243 DOI: 10.1038/s41525-022-00306-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 05/10/2022] [Indexed: 11/23/2022] Open
Abstract
The USH2A variant c.2276 G > T (p.(Cys759Phe)) has been described by many authors as a frequent cause of autosomal recessive retinitis pigmentosa (arRP). However, this is in contrast with the description of two asymptomatic individuals homozygous for this variant. We therefore assessed pathogenicity of the USH2A c.2276 G > T variant using extensive genetic and functional analyses. Whole genome sequencing and optical genome mapping were performed for three arRP cases homozygous for USH2A c.2276 G > T to exclude alternative genetic causes. A minigene splice assay was designed to investigate the effect of c.2276 G > T on pre-mRNA splicing, in presence or absence of the nearby c.2256 T > C variant. Moreover, an ush2ap.(Cys771Phe) zebrafish knock-in model mimicking human p.(Cys759Phe) was generated and characterized using functional and immunohistochemical analyses. Besides the homozygous c.2276 G > T USH2A variant, no alternative genetic causes were identified. Evaluation of the ush2ap.(Cys771Phe) zebrafish model revealed strongly reduced levels of usherin expression at the photoreceptor periciliary membrane, increased levels of rhodopsin localization in the photoreceptor cell body and decreased electroretinogram (ERG) b-wave amplitudes compared to wildtype controls. In conclusion, we confirmed pathogenicity of USH2A c.2276 G > T (p.(Cys759Phe)). Consequently, cases homozygous for c.2276 G > T can now receive a definite genetic diagnosis and can be considered eligible for receiving future QR-421a-mediated exon 13 skipping therapy.
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Cusumano A, Roshanravan H, Chao-Shern C, Sebastiani J, Levialdi Ghiron JH, DeDionisio L, Moore T. Genetic prescreening of a candidate for laser refractive surgery identifies risk for inadequate tissue response: a case report. J Med Case Rep 2022; 16:207. [PMID: 35578349 PMCID: PMC9109339 DOI: 10.1186/s13256-022-03395-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 03/31/2022] [Indexed: 12/01/2022] Open
Abstract
Background Inadequate response to corneal laser refractive surgery, e.g., ectatic corneal diseases, may not be identified by conventional examinations, hence creating therapeutic uncertainty. Herein we demonstrate the application of genetic prescreening to augment preassessment for corneal laser refractive surgery and highlight the ability to prevent the possibility of enrolling a subject at risk for developing ectatic corneal diseases. Case presentation Preoperative tests were performed alongside deoxyribonucleic acid (DNA) sequencing of 75 genes specific to the structure and health of the eye of a 44-year-old Caucasian male candidate for corneal laser refractive surgery. The patient had no medical, family, or psychosocial history, nor symptoms that could lead to suspect any corneal abnormalities, and conventional preoperative tests confirmed that no corneal abnormalities were present. The sequencing results uncovered rare DNA variants within the ADGRV1, PTK2, ZNF469, and KRT15 genes. These variants were considered potential risk factors for inadequate response in the patient post corneal laser refractive surgery. Subsequent reevaluation with three different last-generation corneal tomographers identified in the left eye a “warning” for a deformity of the posterior profile of the cornea. Conclusions Genetic prescreening identifies potential risk of inadequate response to corneal laser refractive surgery where current technologies in use may lead to a hazardous predictive diagnostic uncertainty.
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Delmaghani S, El-Amraoui A. The genetic and phenotypic landscapes of Usher syndrome: from disease mechanisms to a new classification. Hum Genet 2022. [PMID: 35353227 DOI: 10.1007/s00439-022-02448-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/04/2022] [Indexed: 12/16/2022]
Abstract
Usher syndrome (USH) is the most common cause of deaf–blindness in humans, with a prevalence of about 1/10,000 (~ 400,000 people worldwide). Cochlear implants are currently used to reduce the burden of hearing loss in severe-to-profoundly deaf patients, but many promising treatments including gene, cell, and drug therapies to restore the native function of the inner ear and retinal sensory cells are under investigation. The traditional clinical classification of Usher syndrome defines three major subtypes—USH1, 2 and 3—according to hearing loss severity and onset, the presence or absence of vestibular dysfunction, and age at onset of retinitis pigmentosa. Pathogenic variants of nine USH genes have been initially reported: MYO7A, USH1C, PCDH15, CDH23, and USH1G for USH1, USH2A, ADGRV1, and WHRN for USH2, and CLRN1 for USH3. Based on the co-occurrence of hearing and vision deficits, the list of USH genes has been extended to few other genes, but with limited supporting information. A consensus on combined criteria for Usher syndrome is crucial for the development of accurate diagnosis and to improve patient management. In recent years, a wealth of information has been obtained concerning the properties of the Usher proteins, related molecular networks, potential genotype–phenotype correlations, and the pathogenic mechanisms underlying the impairment or loss of hearing, balance and vision. The advent of precision medicine calls for a clear and more precise diagnosis of Usher syndrome, exploiting all the existing data to develop a combined clinical/genetic/network/functional classification for Usher syndrome.
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Miles A, Blair C, Emili A, Tropepe V. Usher syndrome type 1-associated gene, pcdh15b, is required for photoreceptor structural integrity in zebrafish. Dis Model Mech 2021; 14:272551. [PMID: 34668518 PMCID: PMC8669488 DOI: 10.1242/dmm.048965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 10/13/2021] [Indexed: 12/23/2022] Open
Abstract
Blindness associated with Usher syndrome type 1 (USH1) is typically characterized as rod photoreceptor degeneration, followed by secondary loss of cones. The mechanisms leading to blindness are unknown because most genetic mouse models only recapitulate auditory defects. We generated zebrafish mutants for one of the USH1 genes, protocadherin-15b (pcdh15b), a putative cell adhesion molecule. Zebrafish Pcdh15 is expressed exclusively in photoreceptors within calyceal processes (CPs), at the base of the outer segment (OS) and within the synapse. In our mutants, rod and cone photoreceptor integrity is compromised, with early and progressively worsening abnormal OS disc growth and detachment, in part due to weakening CP contacts. These effects were attenuated or exacerbated by growth in dark and bright-light conditions, respectively. We also describe novel evidence for structural defects in synapses of pcdh15b mutant photoreceptors. Cell death does not accompany these defects at early stages, suggesting that photoreceptor structural defects, rather than overt cell loss, may underlie vision deficits. Thus, we present the first genetic animal model of a PCDH15-associated retinopathy that can be used to understand the aetiology of blindness in USH1. This article has an associated First Person interview with the first author of the paper. Summary: We present one of the first genetic animal mutants for PCDH15 that displays a severe, early retinopathy and suggests that zebrafish could be a useful model for PCDH15-associated retinal phenotypes.
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Affiliation(s)
- Amanda Miles
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Clarke Blair
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Andrew Emili
- Center for Network Systems Biology, Boston University, Boston, MA 02118, USA
| | - Vincent Tropepe
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
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Fakin A, Bonnet C, Kurtenbach A, Mohand-Said S, Zobor D, Stingl K, Testa F, Simonelli F, Sahel JA, Audo I, Zrenner E, Hawlina M, Petit C. Characteristics of Retinitis Pigmentosa Associated with ADGRV1 and Comparison with USH2A in Patients from a Multicentric Usher Syndrome Study Treatrush. Int J Mol Sci 2021; 22:10352. [PMID: 34638692 DOI: 10.3390/ijms221910352] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 11/17/2022] Open
Abstract
In contrast to USH2A, variants in ADGRV1 are a minor cause of Usher syndrome type 2, and the associated phenotype is less known. The purpose of the study was to characterize the retinal phenotype of 18 ADGRV1 patients (9 male, 9 female; median age 52 years) and compare it with that of 204 USH2A patients (111 male, 93 female; median age 43 years) in terms of nyctalopia onset, best corrected visual acuity (BCVA), fundus autofluorescence (FAF), and optical coherence tomography (OCT) features. There was no statistical difference in the median age at onset (30 and 18 years; Mann–Whitney U test, p = 0.13); the mean age when 50% of the patients reached legal blindness (≥1.0 log MAR) based on visual acuity (64 years for both groups; log-rank, p = 0.3); the risk of developing advanced retinal degeneration (patch or atrophy) with age (multiple logistic regression, p = 0.8); or the frequency of cystoid macular edema (31% vs. 26%, Fisher’s exact test, p = 0.4). ADGRV1 and USH2A retinopathy were indistinguishable in all major functional and structural characteristics, suggesting that the loss of function of the corresponding proteins produces similar effects in the retina. The results are important for counseling ADGRV1 patients, who represent the minor patient subgroup.
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25
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de Vrieze E, de Bruijn SE, Reurink J, Broekman S, van de Riet V, Aben M, Kremer H, van Wijk E. Efficient Generation of Knock-In Zebrafish Models for Inherited Disorders Using CRISPR-Cas9 Ribonucleoprotein Complexes. Int J Mol Sci 2021; 22:9429. [PMID: 34502338 PMCID: PMC8431507 DOI: 10.3390/ijms22179429] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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: 07/30/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 12/17/2022] Open
Abstract
CRISPR-Cas9-based genome-editing is a highly efficient and cost-effective method to generate zebrafish loss-of-function alleles. However, introducing patient-specific variants into the zebrafish genome with CRISPR-Cas9 remains challenging. Targeting options can be limited by the predetermined genetic context, and the efficiency of the homology-directed DNA repair pathway is relatively low. Here, we illustrate our efficient approach to develop knock-in zebrafish models using two previously variants associated with hereditary sensory deficits. We employ sgRNA-Cas9 ribonucleoprotein (RNP) complexes that are micro-injected into the first cell of fertilized zebrafish eggs together with an asymmetric, single-stranded DNA template containing the variant of interest. The introduction of knock-in events was confirmed by massive parallel sequencing of genomic DNA extracted from a pool of injected embryos. Simultaneous morpholino-induced blocking of a key component of the non-homologous end joining DNA repair pathway, Ku70, improved the knock-in efficiency for one of the targets. Our use of RNP complexes provides an improved knock-in efficiency as compared to previously published studies. Correct knock-in events were identified in 3-8% of alleles, and 30-45% of injected animals had the target variant in their germline. The detailed technical and procedural insights described here provide a valuable framework for the efficient development of knock-in zebrafish models.
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Affiliation(s)
- Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (S.B.); (V.v.d.R.); (H.K.); (E.v.W.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
| | - Suzanne E. de Bruijn
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Janine Reurink
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Sanne Broekman
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (S.B.); (V.v.d.R.); (H.K.); (E.v.W.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
| | - Vince van de Riet
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (S.B.); (V.v.d.R.); (H.K.); (E.v.W.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
| | - Marco Aben
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (S.B.); (V.v.d.R.); (H.K.); (E.v.W.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (S.B.); (V.v.d.R.); (H.K.); (E.v.W.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands; (S.E.d.B.); (J.R.); (M.A.)
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26
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Schellens R, de Vrieze E, Graave P, Broekman S, Nagel-Wolfrum K, Peters T, Kremer H, Collin RWJ, van Wijk E. Zebrafish as a Model to Evaluate a CRISPR/Cas9-Based Exon Excision Approach as a Future Treatment Option for EYS-Associated Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms22179154. [PMID: 34502064 PMCID: PMC8431288 DOI: 10.3390/ijms22179154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 07/30/2021] [Revised: 08/18/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Retinitis pigmentosa (RP) is an inherited retinal disease (IRD) with an overall prevalence of 1 in 4000 individuals. Mutations in EYS (Eyes shut homolog) are among the most frequent causes of non-syndromic autosomal recessively inherited RP and act via a loss-of-function mechanism. In light of the recent successes for other IRDs, we investigated the therapeutic potential of exon skipping for EYS-associated RP. CRISPR/Cas9 was employed to generate zebrafish from which the region encompassing the orthologous exons 37-41 of human EYS (eys exons 40-44) was excised from the genome. The excision of these exons was predicted to maintain the open reading frame and to result in the removal of exactly one Laminin G and two EGF domains. Although the eysΔexon40-44 transcript was found at levels comparable to wild-type eys, and no unwanted off-target modifications were identified within the eys coding sequence after single-molecule sequencing, EysΔexon40-44 protein expression could not be detected. Visual motor response experiments revealed that eysΔexon40-44 larvae were visually impaired and histological analysis revealed a progressive degeneration of the retinal outer nuclear layer in these zebrafish. Altogether, the data obtained in our zebrafish model currently provide no indications for the skipping of EYS exons 37-41 as an effective future treatment strategy for EYS-associated RP.
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Affiliation(s)
- Renske Schellens
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
| | - Pam Graave
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Sanne Broekman
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
| | - Kerstin Nagel-Wolfrum
- Institute for Molecular Physiology, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany;
- Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Theo Peters
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Rob W. J. Collin
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Correspondence:
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27
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Toms M, Dubis AM, de Vrieze E, Tracey-White D, Mitsios A, Hayes M, Broekman S, Baxendale S, Utoomprurkporn N, Bamiou D, Bitner-Glindzicz M, Webster AR, Van Wijk E, Moosajee M. Clinical and preclinical therapeutic outcome metrics for USH2A-related disease. Hum Mol Genet 2021; 29:1882-1899. [PMID: 31998945 PMCID: PMC7372554 DOI: 10.1093/hmg/ddaa004] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [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: 10/23/2019] [Revised: 12/20/2019] [Accepted: 12/29/2019] [Indexed: 02/06/2023] Open
Abstract
USH2A variants are the most common cause of Usher syndrome type 2, characterized by congenital sensorineural hearing loss and retinitis pigmentosa (RP), and also contribute to autosomal recessive non-syndromic RP. Several treatment strategies are under development; however, sensitive clinical trial endpoint metrics to determine therapeutic efficacy have not been identified. In the present study, we have performed longitudinal retrospective examination of the retinal and auditory symptoms in (i) 56 biallelic molecularly confirmed USH2A patients and (ii) ush2a mutant zebrafish to identify metrics for the evaluation of future clinical trials and rapid preclinical screening studies. The patient cohort showed a statistically significant correlation between age and both rate of constriction for the ellipsoid zone length and hyperautofluorescent outer retinal ring area. Visual acuity and pure tone audiograms are not suitable outcome measures. Retinal examination of the novel ush2au507 zebrafish mutant revealed a slowly progressive degeneration of predominantly rods, accompanied by rhodopsin and blue cone opsin mislocalization from 6 to 12 months of age with lysosome-like structures observed in the photoreceptors. This was further evaluated in the ush2armc zebrafish model, which revealed similar changes in photopigment mislocalization with elevated autophagy levels at 6 days post fertilization, indicating a more severe genotype-phenotype correlation and providing evidence of new insights into the pathophysiology underlying USH2A-retinal disease.
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Affiliation(s)
- Maria Toms
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Adam M Dubis
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK.,Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen 6525 HR, The Netherlands
| | - Dhani Tracey-White
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Andreas Mitsios
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK.,Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Matthew Hayes
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Sanne Broekman
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen 6525 HR, The Netherlands
| | - Sarah Baxendale
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK
| | - Nattawan Utoomprurkporn
- UCL Ear Institute, University College London, London WC1X 8EE, UK.,Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Doris Bamiou
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | | | - Andrew R Webster
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK.,Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Erwin Van Wijk
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen 6525 HR, The Netherlands
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK.,Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK.,UCL Ear Institute, University College London, London WC1X 8EE, UK
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28
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Stemerdink M, García-Bohórquez B, Schellens R, Garcia-Garcia G, Van Wijk E, Millan JM. Genetics, pathogenesis and therapeutic developments for Usher syndrome type 2. Hum Genet 2021. [PMID: 34331125 DOI: 10.1007/s00439-021-02324-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/24/2021] [Indexed: 12/28/2022]
Abstract
Usher syndrome (USH) is a rare, autosomal recessively inherited disorder resulting in a combination of sensorineural hearing loss and a progressive loss of vision resulting from retinitis pigmentosa (RP), occasionally accompanied by an altered vestibular function. More and more evidence is building up indicating that also sleep deprivation, olfactory dysfunction, deficits in tactile perception and reduced sperm motility are part of the disease etiology. USH can be clinically classified into three different types, of which Usher syndrome type 2 (USH2) is the most prevalent. In this review, we, therefore, assess the genetic and clinical aspects, available models and therapeutic developments for USH2. Mutations in USH2A, ADGRV1 and WHRN have been described to be responsible for USH2, with USH2A being the most frequently mutated USH-associated gene, explaining 50% of all cases. The proteins encoded by the USH2 genes together function in a dynamic protein complex that, among others, is found at the photoreceptor periciliary membrane and at the base of the hair bundles of inner ear hair cells. To unravel the pathogenic mechanisms underlying USH2, patient-derived cellular models and animal models including mouse, zebrafish and drosophila, have been generated that all in part mimic the USH phenotype. Multiple cellular and genetic therapeutic approaches are currently under development for USH2, mainly focused on preserving or partially restoring the visual function of which one is already in the clinical phase. These developments are opening a new gate towards a possible treatment for USH2 patients.
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29
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Mauriac SA, Géléoc GSG. A hop, skip, and a jump to evade USH2A deaf-blindness mutations. Mol Ther 2021; 29:2391-2393. [PMID: 34297918 DOI: 10.1016/j.ymthe.2021.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Stéphanie A Mauriac
- Department of Otolaryngology, Head Neck and Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gwenaëlle S G Géléoc
- Department of Otolaryngology, Head Neck and Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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30
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Fuster-García C, García-Bohórquez B, Rodríguez-Muñoz A, Aller E, Jaijo T, Millán JM, García-García G. Usher Syndrome: Genetics of a Human Ciliopathy. Int J Mol Sci 2021; 22:ijms22136723. [PMID: 34201633 PMCID: PMC8268283 DOI: 10.3390/ijms22136723] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 12/21/2022] Open
Abstract
Usher syndrome (USH) is an autosomal recessive syndromic ciliopathy characterized by sensorineural hearing loss, retinitis pigmentosa and, sometimes, vestibular dysfunction. There are three clinical types depending on the severity and age of onset of the symptoms; in addition, ten genes are reported to be causative of USH, and six more related to the disease. These genes encode proteins of a diverse nature, which interact and form a dynamic protein network called the “Usher interactome”. In the organ of Corti, the USH proteins are essential for the correct development and maintenance of the structure and cohesion of the stereocilia. In the retina, the USH protein network is principally located in the periciliary region of the photoreceptors, and plays an important role in the maintenance of the periciliary structure and the trafficking of molecules between the inner and the outer segments of photoreceptors. Even though some genes are clearly involved in the syndrome, others are controversial. Moreover, expression of some USH genes has been detected in other tissues, which could explain their involvement in additional mild comorbidities. In this paper, we review the genetics of Usher syndrome and the spectrum of mutations in USH genes. The aim is to identify possible mutation associations with the disease and provide an updated genotype–phenotype correlation.
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Affiliation(s)
- Carla Fuster-García
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain; (C.F.-G.); (B.G.-B.); (A.R.-M.); (E.A.); (T.J.); (G.G.-G.)
- Unidad Mixta de Enfermedades Raras IIS La Fe-Centro de Investigación Príncipe Felipe, 46026 Valencia, Spain
- Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, 46026 Valencia, Spain
| | - Belén García-Bohórquez
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain; (C.F.-G.); (B.G.-B.); (A.R.-M.); (E.A.); (T.J.); (G.G.-G.)
- Unidad Mixta de Enfermedades Raras IIS La Fe-Centro de Investigación Príncipe Felipe, 46026 Valencia, Spain
| | - Ana Rodríguez-Muñoz
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain; (C.F.-G.); (B.G.-B.); (A.R.-M.); (E.A.); (T.J.); (G.G.-G.)
- Unidad Mixta de Enfermedades Raras IIS La Fe-Centro de Investigación Príncipe Felipe, 46026 Valencia, Spain
| | - Elena Aller
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain; (C.F.-G.); (B.G.-B.); (A.R.-M.); (E.A.); (T.J.); (G.G.-G.)
- Unidad Mixta de Enfermedades Raras IIS La Fe-Centro de Investigación Príncipe Felipe, 46026 Valencia, Spain
- Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, 46026 Valencia, Spain
- Genetics Unit, Hospital Universitario y Politécnico La Fe, 46026 Valencia, Spain
| | - Teresa Jaijo
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain; (C.F.-G.); (B.G.-B.); (A.R.-M.); (E.A.); (T.J.); (G.G.-G.)
- Unidad Mixta de Enfermedades Raras IIS La Fe-Centro de Investigación Príncipe Felipe, 46026 Valencia, Spain
- Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, 46026 Valencia, Spain
- Genetics Unit, Hospital Universitario y Politécnico La Fe, 46026 Valencia, Spain
| | - José M. Millán
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain; (C.F.-G.); (B.G.-B.); (A.R.-M.); (E.A.); (T.J.); (G.G.-G.)
- Unidad Mixta de Enfermedades Raras IIS La Fe-Centro de Investigación Príncipe Felipe, 46026 Valencia, Spain
- Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, 46026 Valencia, Spain
- Correspondence:
| | - Gema García-García
- Molecular, Cellular and Genomics Biomedicine Research Group, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain; (C.F.-G.); (B.G.-B.); (A.R.-M.); (E.A.); (T.J.); (G.G.-G.)
- Unidad Mixta de Enfermedades Raras IIS La Fe-Centro de Investigación Príncipe Felipe, 46026 Valencia, Spain
- Biomedical Research Network for Rare Diseases, Hospital Universitario y Politécnico La Fe, 46026 Valencia, Spain
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31
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Quint WH, Tadema KCD, de Vrieze E, Lukowicz RM, Broekman S, Winkelman BHJ, Hoevenaars M, de Gruiter HM, van Wijk E, Schaeffel F, Meester-Smoor M, Miller AC, Willemsen R, Klaver CCW, Iglesias AI. Loss of Gap Junction Delta-2 (GJD2) gene orthologs leads to refractive error in zebrafish. Commun Biol 2021; 4:676. [PMID: 34083742 PMCID: PMC8175550 DOI: 10.1038/s42003-021-02185-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [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: 11/11/2020] [Accepted: 05/04/2021] [Indexed: 12/20/2022] Open
Abstract
Myopia is the most common developmental disorder of juvenile eyes, and it has become an increasing cause of severe visual impairment. The GJD2 locus has been consistently associated with myopia in multiple independent genome-wide association studies. However, despite the strong genetic evidence, little is known about the functional role of GJD2 in refractive error development. Here, we find that depletion of gjd2a (Cx35.5) or gjd2b (Cx35.1) orthologs in zebrafish, cause changes in the biometry and refractive status of the eye. Our immunohistological and scRNA sequencing studies show that Cx35.5 (gjd2a) is a retinal connexin and its depletion leads to hyperopia and electrophysiological changes in the retina. These findings support a role for Cx35.5 (gjd2a) in the regulation of ocular biometry. Cx35.1 (gjd2b) has previously been identified in the retina, however, we found an additional lenticular role. Lack of Cx35.1 (gjd2b) led to a nuclear cataract that triggered axial elongation. Our results provide functional evidence of a link between gjd2 and refractive error. Quint et al. use zebrafish lines deficient in one of two orthologs of the Gap Junction Delta-2 (GJD2) gene, which is associated with myopia by genome-wide association studies. They link gjd2 with refractive error and report evidence to suggest that gjd2a plays a role in ocular biometry whilst gjd2b, previously found in the retina, possesses an additional lenticular role.
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Affiliation(s)
- Wim H Quint
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands. .,Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands.
| | - Kirke C D Tadema
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Rachel M Lukowicz
- Institute of Neuroscience, University of Oregon, Eugene, United States
| | - Sanne Broekman
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Beerend H J Winkelman
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Cerebellar Coordination and Cognition, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Melanie Hoevenaars
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Erwin van Wijk
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Frank Schaeffel
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
| | - Magda Meester-Smoor
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Adam C Miller
- Institute of Neuroscience, University of Oregon, Eugene, United States
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Caroline C W Klaver
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.,Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.,Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Adriana I Iglesias
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands. .,Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands.
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32
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Dulla K, Slijkerman R, van Diepen HC, Albert S, Dona M, Beumer W, Turunen JJ, Chan HL, Schulkens IA, Vorthoren L, den Besten C, Buil L, Schmidt I, Miao J, Venselaar H, Zang J, Neuhauss SCF, Peters T, Broekman S, Pennings R, Kremer H, Platenburg G, Adamson P, de Vrieze E, van Wijk E. Antisense oligonucleotide-based treatment of retinitis pigmentosa caused by USH2A exon 13 mutations. Mol Ther 2021; 29:2441-2455. [PMID: 33895329 PMCID: PMC8353187 DOI: 10.1016/j.ymthe.2021.04.024] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [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: 02/12/2021] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 12/14/2022] Open
Abstract
Mutations in USH2A are among the most common causes of syndromic and non-syndromic retinitis pigmentosa (RP). The two most recurrent mutations in USH2A, c.2299delG and c.2276G > T, both reside in exon 13. Skipping exon 13 from the USH2A transcript presents a potential treatment modality in which the resulting transcript is predicted to encode a slightly shortened usherin protein. Morpholino-induced skipping of ush2a exon 13 in zebrafish ush2armc1 mutants resulted in the production of usherinΔexon 13 protein and a completely restored retinal function. Antisense oligonucleotides were investigated for their potential to selectively induce human USH2A exon 13 skipping. Lead candidate QR-421a induced a concentration-dependent exon 13 skipping in induced pluripotent stem cell (iPSC)-derived photoreceptor precursors from an Usher syndrome patient homozygous for the c.2299delG mutation. Mouse surrogate mQR-421a reached the retinal outer nuclear layer after a single intravitreal injection and induced a detectable level of exon skipping until at least 6 months post-injection. In conclusion, QR-421a-induced exon skipping proves to be a highly promising treatment option for RP caused by mutations in USH2A exon 13.
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Affiliation(s)
- Kalyan Dulla
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Ralph Slijkerman
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | | | - Silvia Albert
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Margo Dona
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Wouter Beumer
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Janne J Turunen
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Hee Lam Chan
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Iris A Schulkens
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Lars Vorthoren
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | | | - Levi Buil
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Iris Schmidt
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Jiayi Miao
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands
| | - Hanka Venselaar
- Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Jingjing Zang
- University of Zürich, Institute of Molecular Life Sciences, 8057 Zürich, Switzerland
| | - Stephan C F Neuhauss
- University of Zürich, Institute of Molecular Life Sciences, 8057 Zürich, Switzerland
| | - Theo Peters
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Sanne Broekman
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Ronald Pennings
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Hannie Kremer
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | | | - Peter Adamson
- ProQR Therapeutics, Zernikedreef 9, 2333 CK Leiden, the Netherlands; UCL, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.
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33
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Stella SL Jr, Geathers JS, Weber SR, Grillo MA, Barber AJ, Sundstrom JM, Grillo SL. Neurodegeneration, Neuroprotection and Regeneration in the Zebrafish Retina. Cells 2021; 10:633. [PMID: 33809186 DOI: 10.3390/cells10030633] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [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: 12/31/2020] [Revised: 02/10/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022] Open
Abstract
Neurodegenerative retinal diseases, such as glaucoma and diabetic retinopathy, involve a gradual loss of neurons in the retina as the disease progresses. Central nervous system neurons are not able to regenerate in mammals, therefore, an often sought after course of treatment for neuronal loss follows a neuroprotective or regenerative strategy. Neuroprotection is the process of preserving the structure and function of the neurons that have survived a harmful insult; while regenerative approaches aim to replace or rewire the neurons and synaptic connections that were lost, or induce regrowth of damaged axons or dendrites. In order to test the neuroprotective effectiveness or the regenerative capacity of a particular agent, a robust experimental model of retinal neuronal damage is essential. Zebrafish are being used more often in this type of study because their eye structure and development is well-conserved between zebrafish and mammals. Zebrafish are robust genetic tools and are relatively inexpensive to maintain. The large array of functional and behavioral tests available in zebrafish makes them an attractive model for neuroprotection studies. Some common insults used to model retinal disease and study neuroprotection in zebrafish include intense light, chemical toxicity and mechanical damage. This review covers the existing retinal neuroprotection and regeneration literature in the zebrafish and highlights their potential for future studies.
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34
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Noel NCL, MacDonald IM, Allison WT. Zebrafish Models of Photoreceptor Dysfunction and Degeneration. Biomolecules 2021; 11:78. [PMID: 33435268 PMCID: PMC7828047 DOI: 10.3390/biom11010078] [Citation(s) in RCA: 9] [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: 12/19/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/15/2022] Open
Abstract
Zebrafish are an instrumental system for the generation of photoreceptor degeneration models, which can be utilized to determine underlying causes of photoreceptor dysfunction and death, and for the analysis of potential therapeutic compounds, as well as the characterization of regenerative responses. We review the wealth of information from existing zebrafish models of photoreceptor disease, specifically as they relate to currently accepted taxonomic classes of human rod and cone disease. We also highlight that rich, detailed information can be derived from studying photoreceptor development, structure, and function, including behavioural assessments and in vivo imaging of zebrafish. Zebrafish models are available for a diversity of photoreceptor diseases, including cone dystrophies, which are challenging to recapitulate in nocturnal mammalian systems. Newly discovered models of photoreceptor disease and drusenoid deposit formation may not only provide important insights into pathogenesis of disease, but also potential therapeutic approaches. Zebrafish have already shown their use in providing pre-clinical data prior to testing genetic therapies in clinical trials, such as antisense oligonucleotide therapy for Usher syndrome.
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Affiliation(s)
- Nicole C. L. Noel
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
| | - Ian M. MacDonald
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, AB T6G 2R7, Canada
| | - W. Ted Allison
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2M8, Canada
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35
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Abstract
Bilallelic variants in the USH2A gene can cause Usher syndrome type 2 and non-syndromic retinitis pigmentosa. In both disorders, the retinal phenotype involves progressive rod photoreceptor loss resulting in nyctalopia and a constricted visual field, followed by subsequent cone degeneration, leading to the loss of central vision and severe visual impairment. The USH2A gene raises many challenges for researchers and clinicians due to a broad spectrum of mutations, a large gene size hampering gene therapy development and limited knowledge on its pathogenicity. Patients with Usher type 2 may benefit from hearing aids or cochlear implants to correct their hearing defects, but there are currently no approved treatments available for the USH2A-retinopathy. Several treatment strategies, including antisense oligonucleotides and translational readthrough inducing drugs, have shown therapeutic promise in preclinical studies. Further understanding of the pathogenesis and natural history of USH2A-related disorders is required to develop innovative treatments and design clinical trials based on reliable outcome measures. The present review will discuss the current knowledge about USH2A, the emerging therapeutics and existing challenges.
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Affiliation(s)
- Lyes Toualbi
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, EC1V 9EL, UK; Ocular Genomics and Therapeutics Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Maria Toms
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, EC1V 9EL, UK; Ocular Genomics and Therapeutics Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Mariya Moosajee
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, EC1V 9EL, UK; Ocular Genomics and Therapeutics Laboratory, The Francis Crick Institute, London, NW1 1AT, UK; Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK; Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK.
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36
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Inaba A, Maeda A, Yoshida A, Kawai K, Hirami Y, Kurimoto Y, Kosugi S, Takahashi M. Truncating Variants Contribute to Hearing Loss and Severe Retinopathy in USH2A-Associated Retinitis Pigmentosa in Japanese Patients. Int J Mol Sci 2020; 21:ijms21217817. [PMID: 33105608 PMCID: PMC7659936 DOI: 10.3390/ijms21217817] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 09/11/2020] [Revised: 10/19/2020] [Accepted: 10/19/2020] [Indexed: 01/19/2023] Open
Abstract
USH2A is a common causal gene of retinitis pigmentosa (RP), a progressive blinding disease due to retinal degeneration. Genetic alterations in USH2A can lead to two types of RP, non-syndromic and syndromic RP, which is called Usher syndrome, with impairments of vision and hearing. The complexity of the genotype–phenotype correlation in USH2A-associated RP (USH2A-RP) has been reported. Genetic and clinical characterization of USH2A-RP has not been performed in Japanese patients. In this study, genetic analyses were performed using targeted panel sequencing in 525 Japanese RP patients. Pathogenic variants of USH2A were identified in 36 of 525 (6.9%) patients and genetic features of USH2A-RP were characterized. Among 36 patients with USH2A-RP, 11 patients had syndromic RP with congenital hearing problems. Amino acid changes due to USH2A alterations were similarly located throughout entire regions of the USH2A protein structure in non-syndromic and syndromic RP cases. Notably, truncating variants were detected in all syndromic patients with a more severe retinal phenotype as compared to non-syndromic RP cases. Taken together, truncating variants could contribute to more serious functional and tissue damages in Japanese patients, suggesting important roles for truncating mutations in the pathogenesis of syndromic USH2A-RP.
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Affiliation(s)
- Akira Inaba
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo 650-0047, Japan; (A.I.); (A.Y.); (K.K.); (Y.H.); (Y.K.); (M.T.)
- Laboratory for Retinal Regeneration, RIKEN, Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
- Department of Medical Ethics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan;
| | - Akiko Maeda
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo 650-0047, Japan; (A.I.); (A.Y.); (K.K.); (Y.H.); (Y.K.); (M.T.)
- Laboratory for Retinal Regeneration, RIKEN, Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
- Correspondence: ; Tel.: +81-(0)78-306-3305
| | - Akiko Yoshida
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo 650-0047, Japan; (A.I.); (A.Y.); (K.K.); (Y.H.); (Y.K.); (M.T.)
- Laboratory for Retinal Regeneration, RIKEN, Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Kanako Kawai
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo 650-0047, Japan; (A.I.); (A.Y.); (K.K.); (Y.H.); (Y.K.); (M.T.)
- Laboratory for Retinal Regeneration, RIKEN, Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Yasuhiko Hirami
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo 650-0047, Japan; (A.I.); (A.Y.); (K.K.); (Y.H.); (Y.K.); (M.T.)
- Laboratory for Retinal Regeneration, RIKEN, Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Yasuo Kurimoto
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo 650-0047, Japan; (A.I.); (A.Y.); (K.K.); (Y.H.); (Y.K.); (M.T.)
- Laboratory for Retinal Regeneration, RIKEN, Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Shinji Kosugi
- Department of Medical Ethics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan;
| | - Masayo Takahashi
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Hyogo 650-0047, Japan; (A.I.); (A.Y.); (K.K.); (Y.H.); (Y.K.); (M.T.)
- Laboratory for Retinal Regeneration, RIKEN, Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
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Whatley M, Francis A, Ng ZY, Khoh XE, Atlas MD, Dilley RJ, Wong EYM. Usher Syndrome: Genetics and Molecular Links of Hearing Loss and Directions for Therapy. Front Genet 2020; 11:565216. [PMID: 33193648 PMCID: PMC7642844 DOI: 10.3389/fgene.2020.565216] [Citation(s) in RCA: 12] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/21/2020] [Indexed: 12/19/2022] Open
Abstract
Usher syndrome (USH) is an autosomal recessive (AR) disorder that permanently and severely affects the senses of hearing, vision, and balance. Three clinically distinct types of USH have been identified, decreasing in severity from Type 1 to 3, with symptoms of sensorineural hearing loss (SNHL), retinitis pigmentosa (RP), and vestibular dysfunction. There are currently nine confirmed and two suspected USH-causative genes, and a further three candidate loci have been mapped. The proteins encoded by these genes form complexes that play critical roles in the development and maintenance of cellular structures within the inner ear and retina, which have minimal capacity for repair or regeneration. In the cochlea, stereocilia are located on the apical surface of inner ear hair cells (HC) and are responsible for transducing mechanical stimuli from sound pressure waves into chemical signals. These signals are then detected by the auditory nerve fibers, transmitted to the brain and interpreted as sound. Disease-causing mutations in USH genes can destabilize the tip links that bind the stereocilia to each other, and cause defects in protein trafficking and stereocilia bundle morphology, thereby inhibiting mechanosensory transduction. This review summarizes the current knowledge on Usher syndrome with a particular emphasis on mutations in USH genes, USH protein structures, and functional analyses in animal models. Currently, there is no cure for USH. However, the genetic therapies that are rapidly developing will benefit from this compilation of detailed genetic information to identify the most effective strategies for restoring functional USH proteins.
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Affiliation(s)
- Meg Whatley
- Ear Science Institute Australia, Nedlands, WA, Australia
| | - Abbie Francis
- Ear Science Institute Australia, Nedlands, WA, Australia
- Emergency Medicine, The University of Western Australia, Nedlands, WA, Australia
| | - Zi Ying Ng
- Ear Science Institute Australia, Nedlands, WA, Australia
| | - Xin Ee Khoh
- Ear Science Institute Australia, Nedlands, WA, Australia
- School of Human Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Marcus D. Atlas
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
| | - Rodney J. Dilley
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
- Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, WA, Australia
| | - Elaine Y. M. Wong
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
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Oh JK, Levi SR, Kim J, Lima de Carvalho JR, Ryu J, Sparrow JR, Tsang SH. Differences in Intraretinal Pigment Migration Across Inherited Retinal Dystrophies. Am J Ophthalmol 2020; 217:252-260. [PMID: 32442431 DOI: 10.1016/j.ajo.2020.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 01/20/2020] [Revised: 04/15/2020] [Accepted: 05/08/2020] [Indexed: 01/12/2023]
Abstract
PURPOSE To determine whether there are differences in the prevalence of intraretinal pigment migration (IPM) across ages and genetic causes of inherited retinal dystrophies (IRDs). DESIGN Retrospective cohort study. METHODS Patients were evaluated at a single tertiary referral center. All patients with a clinical diagnosis of IRD and confirmatory genetic testing were included in these analyses. A total of 392 patients fit inclusion criteria, and 151 patients were excluded based on inconclusive genetic testing. Patients were placed into 3 groups, ciliary and ciliary-related photoreceptor, nonciliary photoreceptor, and retinal pigment epithelium (RPE), based on the cellular expression of the gene and the primary affected cell type. The presence of IPM was evaluated by using slit lamp biomicroscopy, indirect ophthalmoscopy, and wide-field color fundus photography. RESULTS IPM was seen in 257 of 339 patients (75.8%) with mutations in photoreceptor-specific genes and in 18 of 53 patients (34.0%) with mutations in RPE-specific genes (P < .0001). Pairwise analysis following stratification by age and gene category suggested significant differences at all age groups between patients with mutations in photoreceptor-specific genes and patients with mutations in RPE-specific genes (P < .05). A fitted multivariate logistic regression model was produced and demonstrated that the incidence of IPM increases as a function of both age and gene category. CONCLUSIONS IPM is a finding more commonly observed in IRDs caused by mutations in photoreceptor-specific genes than RPE-specific genes. The absence of IPM does not always rule out IRD and should raise suspicion for disease mutations in RPE-specific genes.
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Affiliation(s)
- Jin Kyun Oh
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, USA; College of Medicine, State University of New York at Downstate Medical Center, Brooklyn, New York, USA
| | - Sarah R Levi
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, USA
| | - Joonpyo Kim
- Department of Statistics, Seoul National University, Seoul, South Korea
| | - Jose Ronaldo Lima de Carvalho
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, USA; Department of Ophthalmology, Empresa Brasileira de Servicos Hospitalares, Hospital das Clinicas de Pernambuco, Federal University of Pernambuco, Recife, Pernambuco, Brazil; Department of Ophthalmology, Federal University of São Paulo, São Paulo, São Paulo, Brazil
| | - Joseph Ryu
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, USA
| | - Janet R Sparrow
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, USA; Department of Pathology and Cell Biology, and Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, New York, USA; Department of Pathology & Cell Biology, and Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, NY, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, USA; Department of Pathology and Cell Biology, and Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, New York, USA; Department of Pathology & Cell Biology, and Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, NY, USA.
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39
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Yu D, Zou J, Chen Q, Zhu T, Sui R, Yang J. Structural modeling, mutation analysis, and in vitro expression of usherin, a major protein in inherited retinal degeneration and hearing loss. Comput Struct Biotechnol J 2020; 18:1363-1382. [PMID: 32637036 PMCID: PMC7317166 DOI: 10.1016/j.csbj.2020.05.025] [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] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 11/15/2022] Open
Abstract
Usherin is the most common causative protein associated with autosomal recessive retinitis pigmentosa (RP) and Usher syndrome (USH), which are characterized by retinal degeneration alone and in combination with hearing loss, respectively. Usherin is essential for photoreceptor survival and hair cell bundle integrity. However, the molecular mechanism underlying usherin function in normal and disease conditions is unclear. In this study, we investigated structural models of usherin domains and localization of usherin pathogenic small in-frame mutations, mainly homozygous missense mutations. We found that usherin fibronectin III (FN3) domains and most laminin-related domains have a β-sandwich structure. Some FN3 domains are predicted to interact with each other and with laminin-related domains. The usherin protein may bend at some FN3 linker regions. RP- and USH-associated small in-frame mutations are differentially located in usherin domains. Most of them are located at the periphery of β-sandwiches, with some at the interface between interacting domains. The usherin laminin epidermal growth factor repeats adopt a rod-shaped structure, which is maintained by disulfide bonds. Most missense mutations and deletion of exon 13 in this region disrupt the disulfide bonds and may affect local protein folding. Despite low expression of the recombinant entire protein and protein fragments in mammalian cell culture, usherin FN3 fragments are more robustly expressed and secreted than its laminin-related fragments. Our findings provide new insights into the usherin structure and the disease mechanisms caused by pathogenic small in-frame mutations, which will help inform future experimental research on diagnosis, disease mechanisms, and therapeutic approaches.
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Key Words
- Cell adhesion
- DCC, deleted in colorectal cancer
- FN3, fibronectin III
- GMQE, global quality estimation score
- HGMD, Human Gene Mutation Database
- Hair cell
- I-TASSER, Iterative Threading ASSEmbly Refinement
- LE, laminin EGF
- LG, laminin globular
- LGL, laminin globular-like
- LN, laminin N-terminal
- Membrane protein
- NCBI, National Center for Biotechnology Information
- Photoreceptor
- Protein folding
- QMEAN, qualitative model energy analysis score
- QSQE, Quaternary Structure Quality Estimation
- RMSD, root mean square deviation
- RP, retinitis pigmentosa
- Recombinant protein expression
- Retinitis pigmentosa
- SMTL, SWISS-MODEL template library
- Structural model
- TM-score, template modeling score
- USH, Usher syndrome
- Usher syndrome
- hFc, human Fc fragment
- mFc, mouse Fc fragment
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Affiliation(s)
- Dongmei Yu
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Junhuang Zou
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Qian Chen
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Jun Yang
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, United States
- Division of Otolaryngology, Department of Surgery, University of Utah, Salt Lake City, UT, United States
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Fuster-García C, García-Bohórquez B, Rodríguez-Muñoz A, Millán JM, García-García G. Application of CRISPR Tools for Variant Interpretation and Disease Modeling in Inherited Retinal Dystrophies. Genes (Basel) 2020; 11:E473. [PMID: 32349249 DOI: 10.3390/genes11050473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 04/04/2020] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 12/27/2022] Open
Abstract
Inherited retinal dystrophies are an assorted group of rare diseases that collectively account for the major cause of visual impairment of genetic origin worldwide. Besides clinically, these vision loss disorders present a high genetic and allelic heterogeneity. To date, over 250 genes have been associated to retinal dystrophies with reported causative variants of every nature (nonsense, missense, frameshift, splice-site, large rearrangements, and so forth). Except for a fistful of mutations, most of them are private and affect one or few families, making it a challenge to ratify the newly identified candidate genes or the pathogenicity of dubious variants in disease-associated loci. A recurrent option involves altering the gene in in vitro or in vivo systems to contrast the resulting phenotype and molecular imprint. To validate specific mutations, the process must rely on simulating the precise genetic change, which, until recently, proved to be a difficult endeavor. The rise of the CRISPR/Cas9 technology and its adaptation for genetic engineering now offers a resourceful suite of tools to alleviate the process of functional studies. Here we review the implementation of these RNA-programmable Cas9 nucleases in culture-based and animal models to elucidate the role of novel genes and variants in retinal dystrophies.
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Karjosukarso DW, Ali Z, Peters TA, Zhang JQC, Hoogendoorn ADM, Garanto A, van Wijk E, Jensen LD, Collin RWJ. Modeling ZNF408-Associated FEVR in Zebrafish Results in Abnormal Retinal Vasculature. Invest Ophthalmol Vis Sci 2020; 61:39. [PMID: 32097476 PMCID: PMC7329629 DOI: 10.1167/iovs.61.2.39] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose Familial exudative vitreoretinopathy (FEVR) is an inherited retinal disease in which the retinal vasculature is affected. Patients with FEVR typically lack or have abnormal vasculature in the peripheral retina, the outcome of which can range from mild visual impairment to complete blindness. A missense mutation (p.His455Tyr) in ZNF408 was identified in an autosomal dominant FEVR family. Little, however, is known about the molecular role of ZNF408 and how its defect leads to the clinical features of FEVR. Methods Using CRISPR/Cas9 technology, two homozygous mutant zebrafish models with truncated znf408 were generated, as well as one heterozygous and one homozygous missense znf408 model in which the human p.His455Tyr mutation is mimicked. Results Intriguingly, all three znf408-mutant zebrafish strains demonstrated progressive retinal vascular pathology, initially characterized by a deficient hyaloid vessel development at 5 days postfertilization (dpf) leading to vascular insufficiency in the retina. The generation of stable mutant lines allowed long-term follow up studies, which showed ectopic retinal vascular hyper-sprouting at 90 dpf and extensive vascular leakage at 180 dpf. Conclusions Together, our data demonstrate an important role for znf408 in the development and maintenance of the vascular system within the retina.
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Abstract
Usher syndrome (USH) is a major cause of deaf-blindness in humans, affecting ∼400 000 patients worldwide. Three clinical subtypes, USH1-3, have been defined, with 10 USH genes identified so far. In recent years, in addition to identification of new Usher genes and diagnostic tools, major progress has been made in understanding the role of Usher proteins and how they cooperate through interaction networks to ensure proper development, architecture and function of the stereociliary bundle at the apex of sensory hair cells in the inner ear. Several Usher mouse models of known human Usher genes have been characterized. These mice faithfully reproduce the auditory phenotype associated with Usher syndrome and the vestibular phenotype associated with some mutations in USH genes, particularly USH1. Interestingly, very few mouse models of Usher syndrome recapitulate the retinal phenotype associated with the disease in human. Usher patients can benefit from hearing aids or cochlear implants, which partially alleviate auditory sensory deprivation. However, there are currently no biological treatments available for auditory or visual dysfunction in Usher patients. Development of novel therapies for Usher syndrome has sprouted over the past decade, building on recent progress in gene transfer and new gene editing tools. Promising success demonstrating recovery of hearing and balance functions have been obtained via distinct therapeutic strategies in animal models. Clinical translation to Usher patients, however, calls for further improvements and concerted efforts to overcome the challenges ahead.
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Affiliation(s)
- Gwenaelle G S Géléoc
- Boston Children's Hospital and Harvard Medical School, 3, Blackfan circle, Center for Life Science, 03001, Boston, MA, 02115, United States.
| | - Aziz El-Amraoui
- Unit Progressive Sensory Disorders, Institut Pasteur, INSERM-UMRS1120, Sorbonne Université, 25 rue du Dr. Roux, 75015, Paris, France.
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Abstract
Mutations in USH2A, ADGRV1, and WHRN genes cause Usher syndrome type 2 (USH2) and retinitis pigmentosa (RP). The proteins encoded by these genes form the periciliary membrane complex (PMC) in photoreceptors. Unlike patients, who show retinal degeneration in their second decade of life, mice carrying USH2 mutations have very-late-onset retinal degeneration, although the PMC is disrupted. A similar weak retinal degeneration phenotype was also reported in ush2a mutant zebrafish. The lack of appropriate USH2 animal models hinders our understanding on PMC function in photoreceptors and retinal pathogenesis caused by USH2 mutations. In this study, we examined the molecular composition of the PMC and the morphology of the PMC and its surrounding subcellular structure in Syrian hamster photoreceptors. We demonstrate that the PMC and its neighboring structure in hamsters are similar to those in mice. Therefore, the Syrian hamster may not offer advantages over the mouse as an animal model for USH2 pathogenic studies.
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Affiliation(s)
- Junhuang Zou
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Rong Li
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, USA
| | - Zhongde Wang
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, USA
| | - Jun Yang
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT, USA.
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA.
- Department of Surgery, Division of Otolaryngology, University of Utah, Salt Lake City, UT, USA.
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Samanta A, Stingl K, Kohl S, Ries J, Linnert J, Nagel-Wolfrum K. Ataluren for the Treatment of Usher Syndrome 2A Caused by Nonsense Mutations. Int J Mol Sci 2019; 20:E6274. [PMID: 31842393 DOI: 10.3390/ijms20246274] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [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: 11/22/2019] [Revised: 12/05/2019] [Accepted: 12/10/2019] [Indexed: 12/18/2022] Open
Abstract
The identification of genetic defects that underlie inherited retinal diseases (IRDs) paves the way for the development of therapeutic strategies. Nonsense mutations caused approximately 12% of all IRD cases, resulting in a premature termination codon (PTC). Therefore, an approach that targets nonsense mutations could be a promising pharmacogenetic strategy for the treatment of IRDs. Small molecules (translational read-through inducing drugs; TRIDs) have the potential to mediate the read-through of nonsense mutations by inducing expression of the full-length protein. We provide novel data on the read-through efficacy of Ataluren on a nonsense mutation in the Usher syndrome gene USH2A that causes deaf-blindness in humans. We demonstrate Ataluren´s efficacy in both transiently USH2AG3142*-transfected HEK293T cells and patient-derived fibroblasts by restoring USH2A protein expression. Furthermore, we observed enhanced ciliogenesis in patient-derived fibroblasts after treatment with TRIDs, thereby restoring a phenotype that is similar to that found in healthy donors. In light of recent findings, we validated Ataluren´s efficacy to induce read-through on a nonsense mutation in USH2A-related IRD. In line with published data, our findings support the use of patient-derived fibroblasts as a platform for the validation of preclinical therapies. The excellent biocompatibility combined with sustained read-through efficacy makes Ataluren an ideal TRID for treating nonsense mutations based IRDs.
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Guo Y, Wang P, Ma JH, Cui Z, Yu Q, Liu S, Xue Y, Zhu D, Cao J, Li Z, Tang S, Chen J. Modeling Retinitis Pigmentosa: Retinal Organoids Generated From the iPSCs of a Patient With the USH2A Mutation Show Early Developmental Abnormalities. Front Cell Neurosci 2019; 13:361. [PMID: 31481876 PMCID: PMC6709881 DOI: 10.3389/fncel.2019.00361] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [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: 04/03/2019] [Accepted: 07/23/2019] [Indexed: 11/21/2022] Open
Abstract
Retinitis pigmentosa (RP) represents a group of inherited retinopathies with early-onset nyctalopia followed by progressive photoreceptor degeneration causing irreversible vision loss. Mutations in USH2A are the most common cause of non-syndromic RP. Here, we reprogrammed induced pluripotent stem cells (iPSCs) from a RP patient with a mutation in USH2A (c.8559-2A > G/c.9127_9129delTCC). Then, multilayer retinal organoids including neural retina (NR) and retinal pigment epithelium (RPE) were generated by three-step “induction-reversal culture.” The early retinal organoids derived from the RP patient with the USH2A mutation exhibited significant defects in terms of morphology, immunofluorescence staining and transcriptional profiling. To the best of our knowledge, the pathogenic mutation (c.9127_9129delTCC) in USH2A has not been reported previously among RP patients. Notably, the expression of laminin in the USH2A mutation organoids was significantly lower than in the iPSCs derived from healthy, age- and sex-matched controls during the retinal organogenesis. We also observed that abnormal retinal neuroepithelium differentiation and polarization caused defective retinal progenitor cell development and retinal layer formation, disordered organization of NRs in the presence of the USH2A mutation. Furthermore, the USH2A mutation bearing RPE cells presented abnormal morphology, lacking pigmented foci and showing an apoptotic trend and reduced expression of specific makers, such as MITF, PEDF, and RPE65. In addition, the USH2A mutation organoids had lower expression of cilium-associated (especially CFAP43, PIFO) and dopaminergic synapse-related genes (including DLGAP1, GRIK1, SLC17A7, and SLC17A8), while there was higher expression of neuron apoptotic process-related genes (especially HIF1A, ADARB1, and CASP3). This study may provide essential assistance in the molecular diagnosis and screening of RP. This work recapitulates the pathogenesis of USH2A using patient-specific organoids and demonstrated that alterations in USH2A function due to mutations may lead to cellular and molecular abnormalities.
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Affiliation(s)
- Yonglong Guo
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Key Laboratory for Regenerative Medicine of Ministry of Education, Jinan University, Guangzhou, China
| | - Peiyuan Wang
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Jacey Hongjie Ma
- Aier School of Ophthalmology, Central South University, Changsha, China.,Shenzhen Aier Eye Hospital, Shenzhen, China
| | - Zekai Cui
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China
| | - Quan Yu
- Centric Laboratory, Medical College, Jinan University, Guangzhou, China
| | - Shiwei Liu
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Yunxia Xue
- Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
| | - Deliang Zhu
- Key Laboratory for Regenerative Medicine of Ministry of Education, Jinan University, Guangzhou, China
| | - Jixing Cao
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Zhijie Li
- Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
| | - Shibo Tang
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China
| | - Jiansu Chen
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Key Laboratory for Regenerative Medicine of Ministry of Education, Jinan University, Guangzhou, China.,Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China.,Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
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Slijkerman R, Goloborodko A, Broekman S, de Vrieze E, Hetterschijt L, Peters T, Gerits M, Kremer H, van Wijk E. Poor Splice-Site Recognition in a Humanized Zebrafish Knockin Model for the Recurrent Deep-Intronic c.7595-2144A>G Mutation in USH2A. Zebrafish 2018; 15:597-609. [PMID: 30281416 DOI: 10.1089/zeb.2018.1613] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The frequent deep-intronic c.7595-2144A>G mutation in intron 40 of USH2A generates a high-quality splice donor site, resulting in the incorporation of a pseudoexon (PE40) into the mature transcript that is predicted to prematurely terminate usherin translation. Aberrant USH2A pre-mRNA splicing could be corrected in patient-derived fibroblasts using antisense oligonucleotides. With the aim to study the effect of the c.7595-2144A>G mutation and USH2A splice redirection on retinal function, a humanized zebrafish knockin model was generated, in which 670 basepairs of ush2a intron 40 were exchanged for 557 basepairs of the corresponding human sequence using an optimized CRISPR/Cas9-based protocol. However, in the retina of adult homozygous humanized zebrafish, only 7.4% ± 3.9% of ush2a transcripts contained the human PE40 sequence and immunohistochemical analyses revealed no differences in the usherin expression and localization between the retina of humanized and wild-type zebrafish larvae. Nevertheless, we were able to partially correct aberrant ush2a splicing using a PE40-targeting antisense morpholino. Our results indicate a clear difference in splice-site recognition by the human and zebrafish splicing machinery. Therefore, we propose a protocol in which the effect of human splice-modulating mutations is studied in a zebrafish-specific cell-based splice assay before the generation of a humanized zebrafish knockin model.
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Affiliation(s)
- Ralph Slijkerman
- 1 Department of Otorhinolaryngology, Radboud University Medical Center , Nijmegen, the Netherlands .,2 Radboud Institute for Molecular Life Sciences, and Radboud University Medical Center , Nijmegen, the Netherlands
| | - Alexander Goloborodko
- 3 Department of Human Genetics, Radboud University Medical Center , Nijmegen, the Netherlands
| | - Sanne Broekman
- 1 Department of Otorhinolaryngology, Radboud University Medical Center , Nijmegen, the Netherlands .,4 Donders Institute for Brain , Cognition, and Behavior, Nijmegen, the Netherlands
| | - Erik de Vrieze
- 1 Department of Otorhinolaryngology, Radboud University Medical Center , Nijmegen, the Netherlands .,4 Donders Institute for Brain , Cognition, and Behavior, Nijmegen, the Netherlands
| | - Lisette Hetterschijt
- 1 Department of Otorhinolaryngology, Radboud University Medical Center , Nijmegen, the Netherlands .,4 Donders Institute for Brain , Cognition, and Behavior, Nijmegen, the Netherlands
| | - Theo Peters
- 1 Department of Otorhinolaryngology, Radboud University Medical Center , Nijmegen, the Netherlands .,4 Donders Institute for Brain , Cognition, and Behavior, Nijmegen, the Netherlands
| | - Milou Gerits
- 3 Department of Human Genetics, Radboud University Medical Center , Nijmegen, the Netherlands
| | - Hannie Kremer
- 1 Department of Otorhinolaryngology, Radboud University Medical Center , Nijmegen, the Netherlands .,3 Department of Human Genetics, Radboud University Medical Center , Nijmegen, the Netherlands .,4 Donders Institute for Brain , Cognition, and Behavior, Nijmegen, the Netherlands
| | - Erwin van Wijk
- 1 Department of Otorhinolaryngology, Radboud University Medical Center , Nijmegen, the Netherlands .,4 Donders Institute for Brain , Cognition, and Behavior, Nijmegen, the Netherlands
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Han S, Liu X, Xie S, Gao M, Liu F, Yu S, Sun P, Wang C, Archacki S, Lu Z, Hu X, Qin Y, Qu Z, Huang Y, Lv Y, Tu J, Li J, Yimer TA, Jiang T, Tang Z, Luo D, Chen F, Liu M. Knockout of ush2a gene in zebrafish causes hearing impairment and late onset rod-cone dystrophy. Hum Genet 2018; 137:779-94. [PMID: 30242501 DOI: 10.1007/s00439-018-1936-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 09/16/2018] [Indexed: 10/28/2022]
Abstract
Most cases of Usher syndrome type II (USH2) are due to mutations in the USH2A gene. There are no effective treatments or ideal animal models for this disease, and the pathological mechanisms of USH2 caused by USH2A mutations are still unknown. Here, we constructed a ush2a knockout (ush2a-/-) zebrafish model using TALEN technology to investigate the molecular pathology of USH2. An early onset auditory disorder and abnormal morphology of inner ear stereocilia were identified in the ush2a-/- zebrafish. Consequently, the disruption of Ush2a in zebrafish led to a hearing impairment, like that in mammals. Electroretinography (ERG) test indicated that deletion of Ush2a affected visual function at an early stage, and histological analysis revealed that the photoreceptors progressively degenerated. Rod degeneration occurred prior to cone degeneration in ush2a-/- zebrafish, which is consistent with the classical description of the progression of retinitis pigmentosa (RP). Destruction of the outer segments (OSs) of rods led to the down-regulation of phototransduction cascade proteins at late stage. The expression of Ush1b and Ush1c was up-regulated when Ush2a was null. We also found that disruption of fibronectin assembly at the retinal basement membrane weakened cell adhesion in ush2a-/- mutants. In summary, for the first time, we generated a ush2a knockout zebrafish line with auditory disorder and retinal degeneration which mimicked the symptoms of patients, and revealed that disruption of fibronectin assembly may be one of the factors underlying RP. This model may help us to better understand the pathogenic mechanism and find treatment for USH2 in the future.
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