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Lahlou G, Calvet C, Simon F, Michel V, Alciato L, Plion B, Boutet de Monvel J, Lecomte MJ, Beraneck M, Petit C, Safieddine S. Extended time frame for restoring inner ear function through gene therapy in Usher1G preclinical model. JCI Insight 2024; 9:e169504. [PMID: 38194286 DOI: 10.1172/jci.insight.169504] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 12/28/2023] [Indexed: 01/10/2024] Open
Abstract
Neonatal gene therapy has been shown to prevent inner ear dysfunction in mouse models of Usher syndrome type I (USH1), the most common genetic cause of combined deafness-blindness and vestibular dysfunction. However, hearing onset occurs after birth in mice and in utero in humans, making it questionable how to transpose murine gene therapy outcomes to clinical settings. Here, we sought to extend the therapeutic time window in a mouse model for USH1G to periods corresponding to human neonatal stages, more suitable for intervention in patients. Mice with deletion of Ush1g (Ush1g-/-) were subjected to gene therapy after the hearing onset. The rescue of inner ear hair cell structure was evaluated by confocal imaging and electron microscopy. Hearing and vestibular function were assessed by recordings of the auditory brain stem response and vestibulo-ocular reflex and by locomotor tests. Up to P21, gene therapy significantly restored both the hearing and balance deficits in Ush1g-/- mice. However, beyond this age and up to P30, vestibular function was restored but not hearing. Our data show that effective gene therapy is possible in Ush1g-/- mice well beyond neonatal stages, implying that the therapeutic window for USH1G may be wide enough to be transposable to newborn humans.
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Affiliation(s)
- Ghizlene Lahlou
- Institut Pasteur, Université Paris Cité, Inserm, Institut de l'Audition, Paris, France
- Assistance Publique-Hôpitaux de Paris, Sorbonne University, Service d'ORL et de Chirurgie Cervico-Faciale, DMU ChIR, Paris, France
| | - Charlotte Calvet
- Institut Pasteur, Université Paris Cité, Inserm, Institut de l'Audition, Paris, France
| | - François Simon
- Université Paris Cité, Faculté de Médecine, Paris, France
- Université Paris Cité, CNRS UMR 8002, INCC - Integrative Neuroscience and Cognition Center, Paris, France
- Department of Pediatric Otolaryngology, Assistance Publique-Hôpitaux de Paris, Hôpital Necker-Enfants Malades, Paris, France
| | - Vincent Michel
- Institut Pasteur, INSERM, Pathogenesis of Vascular Infections Unit, Paris, France
| | - Lauranne Alciato
- Institut Pasteur, Université Paris Cité, Inserm, Institut de l'Audition, Paris, France
| | - Baptiste Plion
- Institut Pasteur, Université Paris Cité, Inserm, Institut de l'Audition, Paris, France
| | | | - Marie-José Lecomte
- Institut Pasteur, Université Paris Cité, Inserm, Institut de l'Audition, Paris, France
| | - Mathieu Beraneck
- Université Paris Cité, CNRS UMR 8002, INCC - Integrative Neuroscience and Cognition Center, Paris, France
| | - Christine Petit
- Institut Pasteur, Université Paris Cité, Inserm, Institut de l'Audition, Paris, France
- Collège de France, Paris, France
| | - Saaid Safieddine
- Institut Pasteur, Université Paris Cité, Inserm, Institut de l'Audition, Paris, France
- CNRS, Paris, France
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2
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Li WY, Sui RF. [Advances on gene therapy for USH2A exon 13 related inherited retinal dystrophy]. Zhonghua Yan Ke Za Zhi 2023; 59:1058-1064. [PMID: 38061908 DOI: 10.3760/cma.j.cn112142-20231024-00169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Biallelic pathogenic variants in the USH2A gene result in Usher syndrome type Ⅱ and non-syndromic retinitis pigmentosa, both of which entail the progressive loss of photoreceptors leading to blindness. The cDNA of the USH2A gene is extensive, consisting of 15 606 base pairs, rendering it impractical for delivery via adeno-associated virus vectors for gene replacement therapy. Notably, exon 13 has emerged as a focal point for therapeutic intervention, given its predilection for harboring the most pathogenic variants within USH2A. Recent intervention studies targeting USH2A exon 13 through the utilization of antisense oligonucleotides, genome editing, and RNA editing approaches have exhibited promising therapeutic potential. This paper provides a comprehensive overview of the molecular mechanisms, outcome data, and the challenges associated with the application of these interventions in this domain.
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Affiliation(s)
- W Y Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - R F Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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3
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Riaz S, Sethna S, Duncan T, Naeem MA, Redmond TM, Riazuddin S, Riazuddin S, Carvalho LS, Ahmed ZM. Dual AAV-based PCDH15 gene therapy achieves sustained rescue of visual function in a mouse model of Usher syndrome 1F. Mol Ther 2023; 31:3490-3501. [PMID: 37864333 PMCID: PMC10727994 DOI: 10.1016/j.ymthe.2023.10.017] [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: 06/15/2023] [Revised: 09/20/2023] [Accepted: 10/18/2023] [Indexed: 10/22/2023] Open
Abstract
Mutations in the PCDH15 gene, encoding protocadherin-15, are among the leading causes of Usher syndrome type 1 (USH1F), and account for up to 12% USH1 cases worldwide. A founder truncating variant of PCDH15 has a ∼2% carrier frequency in Ashkenazi Jews accounting for nearly 60% of their USH1 cases. Although cochlear implants can restore hearing perception in USH1 patients, presently there are no effective treatments for the vision loss due to retinitis pigmentosa. We established a founder allele-specific Pcdh15 knockin mouse model as a platform to ascertain therapeutic strategies. Using a dual-vector approach to circumvent the size limitation of adeno-associated virus, we observed robust expression of exogenous PCDH15 in the retinae of Pcdh15KI mice, sustained recovery of electroretinogram amplitudes and key retinoid oxime, substantially improved light-dependent translocation of phototransduction proteins, and enhanced levels of retinal pigment epithelium-derived enzymes. Thus, our data raise hope and pave the way for future gene therapy trials in USH1F subjects.
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Affiliation(s)
- Sehar Riaz
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA; National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore 54500, Pakistan
| | - Saumil Sethna
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Todd Duncan
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Muhammad A Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore 54500, Pakistan
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sheikh Riazuddin
- Jinnah Burn and Reconstructive Surgery Centre, Allama Iqbal Medical Research, University of Health Sciences, Lahore 54500, Pakistan
| | - Saima Riazuddin
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Molecular Biology and Biochemistry, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Livia S Carvalho
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA 6009, Australia; Retinal Genomics and Therapy Group, Lions Eye Institute Ltd, Nedlands, WA 6009, Australia
| | - Zubair M Ahmed
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Molecular Biology and Biochemistry, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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4
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Schott JW, Huang P, Morgan M, Nelson-Brantley J, Koehler A, Renslo B, Büning H, Warnecke A, Schambach A, Staecker H. Third-generation lentiviral gene therapy rescues function in a mouse model of Usher 1B. Mol Ther 2023; 31:3502-3519. [PMID: 37915173 PMCID: PMC10727968 DOI: 10.1016/j.ymthe.2023.10.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/30/2023] [Accepted: 10/27/2023] [Indexed: 11/03/2023] Open
Abstract
Usher syndrome 1B (USH1B) is a devastating genetic disorder with congenital deafness, loss of balance, and blindness caused by mutations in the myosin-VIIa (MYO7A) gene, for which there is currently no cure. We developed a gene therapy approach addressing the vestibulo-cochlear deficits of USH1B using a third-generation, high-capacity lentiviral vector system capable of delivering the large 6,645-bp MYO7A cDNA. Lentivirally delivered MYO7A and co-encoded dTomato were successfully expressed in the cochlear cell line HEI-OC1. In normal-hearing mice, both cochlea and the vestibular organ were efficiently transduced, and ectopic MYO7A overexpression did not show any adverse effects. In Shaker-1 mice, an USH1B disease model based on Myo7a mutation, cochlear and vestibular hair cells, the main inner ear cell types affected in USH1B, were successfully transduced. In homozygous mutant mice, delivery of MYO7A at postnatal day 16 resulted in a trend for partial recovery of auditory function and in strongly reduced balance deficits. Heterozygous mutant mice were found to develop severe hearing loss at 6 months of age without balance deficits, and lentiviral MYO7A gene therapy completely rescued hearing to wild-type hearing thresholds. In summary, this study demonstrates improved hearing and balance function through lentiviral gene therapy in the inner ear.
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Affiliation(s)
- Juliane W Schott
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Peixin Huang
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Michael Morgan
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Jennifer Nelson-Brantley
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Ally Koehler
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Bryan Renslo
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Athanasia Warnecke
- Department of Otolaryngology, Hannover Medical School, 30625 Hannover, Germany
| | - Axel Schambach
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Hinrich Staecker
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA.
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Gilmore WB, Hultgren NW, Chadha A, Barocio SB, Zhang J, Kutsyr O, Flores-Bellver M, Canto-Soler MV, Williams DS. Expression of two major isoforms of MYO7A in the retina: Considerations for gene therapy of Usher syndrome type 1B. Vision Res 2023; 212:108311. [PMID: 37586294 PMCID: PMC10984346 DOI: 10.1016/j.visres.2023.108311] [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: 05/03/2023] [Revised: 07/25/2023] [Accepted: 07/28/2023] [Indexed: 08/18/2023]
Abstract
Usher syndrome type 1B (USH1B) is a deaf-blindness disorder, caused by mutations in the MYO7A gene, which encodes the heavy chain of an unconventional actin-based motor protein. Here, we examined the two retinal isoforms of MYO7A, IF1 and IF2. We compared 3D models of the two isoforms and noted that the 38-amino acid region that is present in IF1 but absent from IF2 affects the C lobe of the FERM1 domain and the opening of a cleft in this potentially important protein binding domain. Expression of each of the two isoforms of human MYO7A and pig and mouse Myo7a was detected in the RPE and neural retina. Quantification by qPCR showed that the expression of IF2 was typically ∼ 7-fold greater than that of IF1. We discuss the implications of these findings for any USH1B gene therapy strategy. Given the current incomplete knowledge of the functions of each isoform, both isoforms should be considered for targeting both the RPE and the neural retina in gene augmentation therapies.
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Affiliation(s)
- W Blake Gilmore
- Department of Ophthalmology and Stein Eye Institute, Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Nan W Hultgren
- Department of Ophthalmology and Stein Eye Institute, Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Abhishek Chadha
- Department of Ophthalmology and Stein Eye Institute, Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Sonia B Barocio
- Department of Ophthalmology and Stein Eye Institute, Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Joyce Zhang
- Department of Ophthalmology and Stein Eye Institute, Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Oksana Kutsyr
- CellSight Ocular Stem Cell and Regeneration Research Program, Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Miguel Flores-Bellver
- CellSight Ocular Stem Cell and Regeneration Research Program, Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado, School of Medicine, Aurora, CO, USA
| | - M Valeria Canto-Soler
- CellSight Ocular Stem Cell and Regeneration Research Program, Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado, School of Medicine, Aurora, CO, USA
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute, Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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6
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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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7
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Peters CW, Hanlon KS, Ivanchenko MV, Zinn E, Linarte EF, Li Y, Levy JM, Liu DR, Kleinstiver BP, Indzhykulian AA, Corey DP. Rescue of hearing by adenine base editing in a humanized mouse model of Usher syndrome type 1F. Mol Ther 2023; 31:2439-2453. [PMID: 37312453 PMCID: PMC10421997 DOI: 10.1016/j.ymthe.2023.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [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: 12/31/2022] [Revised: 04/03/2023] [Accepted: 06/08/2023] [Indexed: 06/15/2023] Open
Abstract
Usher syndrome type 1F (USH1F), characterized by congenital lack of hearing and balance and progressive loss of vision, is caused by mutations in the PCDH15 gene. In the Ashkenazi population, a recessive truncation mutation accounts for a large proportion of USH1F cases. The truncation is caused by a single C→T mutation, which converts an arginine codon to a stop (R245X). To test the potential for base editors to revert this mutation, we developed a humanized Pcdh15R245X mouse model for USH1F. Mice homozygous for the R245X mutation were deaf and exhibited profound balance deficits, while heterozygous mice were unaffected. Here we show that an adenine base editor (ABE) is capable of reversing the R245X mutation to restore the PCDH15 sequence and function. We packaged a split-intein ABE into dual adeno-associated virus (AAV) vectors and delivered them into cochleas of neonatal USH1F mice. Hearing was not restored in a Pcdh15 constitutive null mouse despite base editing, perhaps because of early disorganization of cochlear hair cells. However, injection of vectors encoding the split ABE into a late-deletion conditional Pcdh15 knockout rescued hearing. This study demonstrates the ability of an ABE to correct the PCDH15 R245X mutation in the cochlea and restore hearing.
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Affiliation(s)
- Cole W Peters
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Killian S Hanlon
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, MA 02114, USA
| | | | - Eric Zinn
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, MA 02114, USA
| | | | - Yaqiao Li
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan M Levy
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Artur A Indzhykulian
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, Boston, MA 02114, USA
| | - David P Corey
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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8
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Calabro KR, Boye SL, Boye SE. Optimization of Capillary-Based Western Blotting for MYO7A. Adv Exp Med Biol 2023; 1415:125-130. [PMID: 37440024 DOI: 10.1007/978-3-031-27681-1_19] [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] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Myosin VIIA (MYO7A)-associated Usher syndrome type 1B (USH1B) is a severe disorder that impacts the auditory, vestibular, and visual systems of affected patients. Due to the large size (~7.5 kb) of the MYO7A coding sequence, we have designed a dual adeno-associated virus (AAV) vector-based approach for the treatment of USH1B-related vision loss. Due to the added complexity of dual-AAV gene therapy, careful attention must be paid to the protein products expressed following vector recombination. In order to improve the sensitivity and quantifiability of our immunoassays, we adapted our traditional western blot protocol for use with the Jess™ Simple Western System. Following several rounds of testing, we optimized our protocol for the detection of MYO7A in two of our most frequently used sample types, mouse eyes, and infected HEK293 cell lysates.
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Affiliation(s)
- Kaitlyn R Calabro
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Sanford L Boye
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Shannon E Boye
- Department of Pediatrics, University of Florida, Gainesville, FL, USA.
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9
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Major L, McClements ME, MacLaren RE. New CRISPR Tools to Correct Pathogenic Mutations in Usher Syndrome. Int J Mol Sci 2022; 23:ijms231911669. [PMID: 36232969 PMCID: PMC9569511 DOI: 10.3390/ijms231911669] [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: 09/06/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
Inherited retinal degenerations are a leading cause of blindness in the UK. Significant advances have been made to tackle this issue in recent years, with a pioneering FDA approved gene therapy treatment (Luxturna®), which targets a loss of function mutation in the RPE65 gene. However, there remain notable shortcomings to this form of gene replacement therapy. In particular, the lack of viability for gene sequences exceeding the 4.7 kb adeno-associated virus (AAV) packaging limit or for toxic gain of function mutations. The USH2A gene at ~15.7 kb for instance is too large for AAV delivery: a safe and effective vehicle capable of transducing photoreceptor cells for gene replacement therapy. Usher Syndrome is a clinically and genetically heterogenous deaf-blindness syndrome with autosomal recessive inheritance. The USH2A gene encodes the protein usherin, which localises to the photoreceptor cilium and cochlear hair cells. Mutations in the USH2A gene cause Usher Syndrome type II (USH2), which is the most common subtype of Usher Syndrome and the focus of this review. To date, researchers have been unable to create an efficient, safe editing tool that is small enough to fit inside a single AAV vector for delivery into human cells. This article reviews the potential of CRISPR technology, derived from bacterial defence mechanisms, to overcome these challenges; delivering tools to precisely edit and correct small insertions, deletions and base transitions in USH2A without the need to deliver the full-length gene. Such an ultra-compact therapy could make strides in combating a significant cause of blindness in young people.
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Affiliation(s)
- Lauren Major
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Correspondence:
| | - Michelle E. McClements
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
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10
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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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12
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Schmidt MJ, Gupta A, Bednarski C, Gehrig-Giannini S, Richter F, Pitzler C, Gamalinda M, Galonska C, Takeuchi R, Wang K, Reiss C, Dehne K, Lukason MJ, Noma A, Park-Windhol C, Allocca M, Kantardzhieva A, Sane S, Kosakowska K, Cafferty B, Tebbe J, Spencer SJ, Munzer S, Cheng CJ, Scaria A, Scharenberg AM, Cohnen A, Coco WM. Improved CRISPR genome editing using small highly active and specific engineered RNA-guided nucleases. Nat Commun 2021; 12:4219. [PMID: 34244505 PMCID: PMC8271026 DOI: 10.1038/s41467-021-24454-5] [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] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/14/2021] [Indexed: 12/14/2022] Open
Abstract
Streptococcus pyogenes (Spy) Cas9 has potential as a component of gene therapeutics for incurable diseases. One of its limitations is its large size, which impedes its formulation and delivery in therapeutic applications. Smaller Cas9s are an alternative, but lack robust activity or specificity and frequently recognize longer PAMs. Here, we investigated four uncharacterized, smaller Cas9s and found three employing a "GG" dinucleotide PAM similar to SpyCas9. Protein engineering generated synthetic RNA-guided nucleases (sRGNs) with editing efficiencies and specificities exceeding even SpyCas9 in vitro and in human cell lines on disease-relevant targets. sRGN mRNA lipid nanoparticles displayed manufacturing advantages and high in vivo editing efficiency in the mouse liver. Finally, sRGNs, but not SpyCas9, could be packaged into all-in-one AAV particles with a gRNA and effected robust in vivo editing of non-human primate (NHP) retina photoreceptors. Human gene therapy efforts are expected to benefit from these improved alternatives to existing CRISPR nucleases.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Kui Wang
- Casebia Therapeutics LLC, Cambridge, MA, USA
| | | | | | | | - Akiko Noma
- Casebia Therapeutics LLC, Cambridge, MA, USA
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13
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de Joya EM, Colbert BM, Tang PC, Lam BL, Yang J, Blanton SH, Dykxhoorn DM, Liu X. Usher Syndrome in the Inner Ear: Etiologies and Advances in Gene Therapy. Int J Mol Sci 2021; 22:3910. [PMID: 33920085 PMCID: PMC8068832 DOI: 10.3390/ijms22083910] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 02/06/2023] Open
Abstract
Hearing loss is the most common sensory disorder with ~466 million people worldwide affected, representing about 5% of the population. A substantial portion of hearing loss is genetic. Hearing loss can either be non-syndromic, if hearing loss is the only clinical manifestation, or syndromic, if the hearing loss is accompanied by a collage of other clinical manifestations. Usher syndrome is a syndromic form of genetic hearing loss that is accompanied by impaired vision associated with retinitis pigmentosa and, in many cases, vestibular dysfunction. It is the most common cause of deaf-blindness. Currently cochlear implantation or hearing aids are the only treatments for Usher-related hearing loss. However, gene therapy has shown promise in treating Usher-related retinitis pigmentosa. Here we review how the etiologies of Usher-related hearing loss make it a good candidate for gene therapy and discuss how various forms of gene therapy could be applied to Usher-related hearing loss.
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Affiliation(s)
- Evan M. de Joya
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (E.M.J.); (B.M.C.); (P.-C.T.); (S.H.B.)
- Dr. John T. Macdonald Foundation Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Brett M. Colbert
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (E.M.J.); (B.M.C.); (P.-C.T.); (S.H.B.)
- Dr. John T. Macdonald Foundation Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- Medical Scientist Training Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Pei-Ciao Tang
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (E.M.J.); (B.M.C.); (P.-C.T.); (S.H.B.)
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, FL 33136, USA;
| | - Jun Yang
- John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT 84132, USA;
| | - Susan H. Blanton
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (E.M.J.); (B.M.C.); (P.-C.T.); (S.H.B.)
- Dr. John T. Macdonald Foundation Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Derek M. Dykxhoorn
- Dr. John T. Macdonald Foundation Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Xuezhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (E.M.J.); (B.M.C.); (P.-C.T.); (S.H.B.)
- Dr. John T. Macdonald Foundation Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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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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15
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Dinculescu A, Stupay RM, Deng WT, Dyka FM, Min SH, Boye SL, Chiodo VA, Abrahan CE, Zhu P, Li Q, Strettoi E, Novelli E, Nagel-Wolfrum K, Wolfrum U, Smith WC, Hauswirth WW. AAV-Mediated Clarin-1 Expression in the Mouse Retina: Implications for USH3A Gene Therapy. PLoS One 2016; 11:e0148874. [PMID: 26881841 PMCID: PMC4755610 DOI: 10.1371/journal.pone.0148874] [Citation(s) in RCA: 10] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 01/23/2016] [Indexed: 02/07/2023] Open
Abstract
Usher syndrome type III (USH3A) is an autosomal recessive disorder caused by mutations in clarin-1 (CLRN1) gene, leading to progressive retinal degeneration and sensorineural deafness. Efforts to develop therapies for preventing photoreceptor cell loss are hampered by the lack of a retinal phenotype in the existing USH3 mouse models and by conflicting reports regarding the endogenous retinal localization of clarin-1, a transmembrane protein of unknown function. In this study, we used an AAV-based approach to express CLRN1 in the mouse retina in order to determine the pattern of its subcellular localization in different cell types. We found that all major classes of retinal cells express AAV-delivered CLRN1 driven by the ubiquitous, constitutive small chicken β-actin promoter, which has important implications for the design of future USH3 gene therapy studies. Within photoreceptor cells, AAV-expressed CLRN1 is mainly localized at the inner segment region and outer plexiform layer, similar to the endogenous expression of other usher proteins. Subretinal delivery using a full strength viral titer led to significant loss of retinal function as evidenced by ERG analysis, suggesting that there is a critical limit for CLRN1 expression in photoreceptor cells. Taken together, these results suggest that CLRN1 expression is potentially supported by a variety of retinal cells, and the right combination of AAV vector dose, promoter, and delivery method needs to be selected to develop safe therapies for USH3 disorder.
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Affiliation(s)
- Astra Dinculescu
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
- * E-mail:
| | - Rachel M. Stupay
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Wen-Tao Deng
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Frank M. Dyka
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Seok-Hong Min
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Sanford L. Boye
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Vince A. Chiodo
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Carolina E. Abrahan
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Ping Zhu
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Qiuhong Li
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | | | | | - Kerstin Nagel-Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - W. Clay Smith
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
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17
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Zallocchi M, Binley K, Lad Y, Ellis S, Widdowson P, Iqball S, Scripps V, Kelleher M, Loader J, Miskin J, Peng YW, Wang WM, Cheung L, Delimont D, Mitrophanous KA, Cosgrove D. EIAV-based retinal gene therapy in the shaker1 mouse model for usher syndrome type 1B: development of UshStat. PLoS One 2014; 9:e94272. [PMID: 24705452 PMCID: PMC3976400 DOI: 10.1371/journal.pone.0094272] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 03/14/2014] [Indexed: 01/21/2023] Open
Abstract
Usher syndrome type 1B is a combined deaf-blindness condition caused by mutations in the MYO7A gene. Loss of functional myosin VIIa in the retinal pigment epithelia (RPE) and/or photoreceptors leads to blindness. We evaluated the impact of subretinally delivered UshStat, a recombinant EIAV-based lentiviral vector expressing human MYO7A, on photoreceptor function in the shaker1 mouse model for Usher type 1B that lacks a functional Myo7A gene. Subretinal injections of EIAV-CMV-GFP, EIAV-RK-GFP (photoreceptor specific), EIAV-CMV-MYO7A (UshStat) or EIAV-CMV-Null (control) vectors were performed in shaker1 mice. GFP and myosin VIIa expression was evaluated histologically. Photoreceptor function in EIAV-CMV-MYO7A treated eyes was determined by evaluating α-transducin translocation in photoreceptors in response to low light intensity levels, and protection from light induced photoreceptor degeneration was measured. The safety and tolerability of subretinally delivered UshStat was evaluated in macaques. Expression of GFP and myosin VIIa was confirmed in the RPE and photoreceptors in shaker1 mice following subretinal delivery of the EIAV-CMV-GFP/MYO7A vectors. The EIAV-CMV-MYO7A vector protected the shaker1 mouse photoreceptors from acute and chronic intensity light damage, indicated by a significant reduction in photoreceptor cell loss, and restoration of the α-transducin translocation threshold in the photoreceptors. Safety studies in the macaques demonstrated that subretinal delivery of UshStat is safe and well-tolerated. Subretinal delivery of EIAV-CMV-MYO7A (UshStat) rescues photoreceptor phenotypes in the shaker1 mouse. In addition, subretinally delivered UshStat is safe and well-tolerated in macaque safety studies These data support the clinical development of UshStat to treat Usher type 1B syndrome.
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Affiliation(s)
- Marisa Zallocchi
- Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Katie Binley
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - Yatish Lad
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - Scott Ellis
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - Peter Widdowson
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - Sharifah Iqball
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - Vicky Scripps
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - Michelle Kelleher
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - Julie Loader
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - James Miskin
- Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford, United Kingdom
| | - You-Wei Peng
- Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Wei-Min Wang
- Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Linda Cheung
- Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | - Duane Delimont
- Boys Town National Research Hospital, Omaha, Nebraska, United States of America
| | | | - Dominic Cosgrove
- Boys Town National Research Hospital, Omaha, Nebraska, United States of America
- University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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18
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Trapani I, Colella P, Sommella A, Iodice C, Cesi G, de Simone S, Marrocco E, Rossi S, Giunti M, Palfi A, Farrar GJ, Polishchuk R, Auricchio A. Effective delivery of large genes to the retina by dual AAV vectors. EMBO Mol Med 2014; 6:194-211. [PMID: 24150896 PMCID: PMC3927955 DOI: 10.1002/emmm.201302948] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [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: 05/18/2013] [Revised: 10/10/2013] [Accepted: 10/14/2013] [Indexed: 01/10/2023] Open
Abstract
Retinal gene therapy with adeno-associated viral (AAV) vectors is safe and effective in humans. However, AAV's limited cargo capacity prevents its application to therapies of inherited retinal diseases due to mutations of genes over 5 kb, like Stargardt's disease (STGD) and Usher syndrome type IB (USH1B). Previous methods based on 'forced' packaging of large genes into AAV capsids may not be easily translated to the clinic due to the generation of genomes of heterogeneous size which raise safety concerns. Taking advantage of AAV's ability to concatemerize, we generated dual AAV vectors which reconstitute a large gene by either splicing (trans-splicing), homologous recombination (overlapping), or a combination of the two (hybrid). We found that dual trans-splicing and hybrid vectors transduce efficiently mouse and pig photoreceptors to levels that, albeit lower than those achieved with a single AAV, resulted in significant improvement of the retinal phenotype of mouse models of STGD and USH1B. Thus, dual AAV trans-splicing or hybrid vectors are an attractive strategy for gene therapy of retinal diseases that require delivery of large genes.
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Affiliation(s)
- Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
| | | | - Andrea Sommella
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
| | - Carolina Iodice
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
| | - Giulia Cesi
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
| | - Sonia de Simone
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
| | - Elena Marrocco
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
| | - Settimio Rossi
- Department of Ophthalmology, Second University of NaplesNaples, Italy
| | - Massimo Giunti
- Department of Veterinary Morphophysiology and Animal Production, University of BolognaBologna, Italy
| | - Arpad Palfi
- The School of Genetics & Microbiology, Trinity College DublinDublin, Ireland
| | - Gwyneth J Farrar
- The School of Genetics & Microbiology, Trinity College DublinDublin, Ireland
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM)Naples, Italy
- Medical Genetics, Department of Translational Medicine, Federico II UniversityNaples, Italy
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20
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Colella P, Sommella A, Marrocco E, Di Vicino U, Polishchuk E, Garrido MG, Seeliger MW, Polishchuk R, Auricchio A. Myosin7a deficiency results in reduced retinal activity which is improved by gene therapy. PLoS One 2013; 8:e72027. [PMID: 23991031 PMCID: PMC3753344 DOI: 10.1371/journal.pone.0072027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 07/04/2013] [Indexed: 12/22/2022] Open
Abstract
Mutations in MYO7A cause autosomal recessive Usher syndrome type IB (USH1B), one of the most frequent conditions that combine severe congenital hearing impairment and retinitis pigmentosa. A promising therapeutic strategy for retinitis pigmentosa is gene therapy, however its pre-clinical development is limited by the mild retinal phenotype of the shaker1 (sh1−/−) murine model of USH1B which lacks both retinal functional abnormalities and degeneration. Here we report a significant, early-onset delay of sh1−/− photoreceptor ability to recover from light desensitization as well as a progressive reduction of both b-wave electroretinogram amplitude and light sensitivity, in the absence of significant loss of photoreceptors up to 12 months of age. We additionally show that subretinal delivery to the sh1−/− retina of AAV vectors encoding the large MYO7A protein results in significant improvement of sh1−/− photoreceptor and retinal pigment epithelium ultrastructural anomalies which is associated with improvement of recovery from light desensitization. These findings provide new tools to evaluate the efficacy of experimental therapies for USH1B. In addition, although AAV vectors expressing large genes might have limited clinical applications due to their genome heterogeneity, our data show that AAV-mediated MYO7A gene transfer to the sh1−/− retina is effective.
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Affiliation(s)
| | - Andrea Sommella
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | - Elena Marrocco
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | | | - Elena Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | - Marina Garcia Garrido
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Tuebingen, Germany
| | - Mathias W. Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Tuebingen, Germany
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
- Medical Genetics, Department of Medical Translational Sciences, University of Naples Federico II, Naples, Italy
- * E-mail:
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21
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Palmgren B, Jin Z, Rosenhall U, Duan M. [Gene therapy in hereditary hearing loss. Future therapeutic possibility--maybe combined with stem cells]. Lakartidningen 2008; 105:2406-2410. [PMID: 18831451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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22
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Tazetdinov AM, Dzhemileva LU, Khusnutdinova EK. [Molecular genetics of Usher syndrome]. Genetika 2008; 44:725-733. [PMID: 18727382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Usher syndrome (USH) is inherited in an autosomal recessive mode. The disease is characterized by hearing loss, progressing vision loss, and vestibular dysfunction. In most cases, it is the reason for deafness and blindness in school-age children. The prevalence of USH in the main population is estimated as 4.4 per 100,000 individuals, approximately. The prevalence of heterozygous carriers can reach 1 per 70 normally hearing individuals. There is currently no effective treatment of USH. The patients are provided with hearing aids, but, in case of severe hearing impairement these aids give no effect. In view of this, developing diagnostic methods is important. It is believed that molecular genetic investigations will enable early diagnostics of the syndrome.
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23
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Hashimoto T, Gibbs D, Lillo C, Azarian SM, Legacki E, Zhang XM, Yang XJ, Williams DS. Lentiviral gene replacement therapy of retinas in a mouse model for Usher syndrome type 1B. Gene Ther 2007; 14:584-94. [PMID: 17268537 PMCID: PMC9307148 DOI: 10.1038/sj.gt.3302897] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [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] [Indexed: 12/22/2022]
Abstract
One of the most disabling forms of retinal degeneration occurs in Usher syndrome, since it affects patients who already suffer from deafness. Mutations in the myosin VIIa gene (MYO7A) cause a major subtype of Usher syndrome, type 1B. Owing to the loss of function nature of Usher 1B and the relatively large size of MYO7A, we investigated a lentiviral-based gene replacement therapy in the retinas of MYO7A-null mice. Among the different promoters tested, a CMV-MYO7A chimeric promoter produced wild-type levels of MYO7A in cultured RPE cells and retinas in vivo. Efficacy of the lentiviral therapy was tested by using cell-based assays to analyze the correction of previously defined, MYO7A-null phenotypes in the mouse retina. In vitro, defects in phagosome digestion and melanosome motility were rescued in primary cultures of RPE cells. In vivo, the normal apical location of melanosomes in RPE cells was restored, and the abnormal accumulation of opsin in the photoreceptor connecting cilium was corrected. These results demonstrate that a lentiviral vector can accommodate a large cDNA, such as MYO7A, and mediate correction of important cellular functions in the retina, a major site affected in the Usher syndrome. Therefore, a lentiviral-mediated gene replacement strategy for Usher 1B therapy in the retina appears feasible.
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Affiliation(s)
- T Hashimoto
- Jules Stein Eye Institute, Molecular Biology Institute, UCLA School of Medicine, Los Angeles, CA, USA
| | - D Gibbs
- Departments of Pharmacology and Neurosciences, UCSD School of Medicine, La Jolla, CA, USA
| | - C Lillo
- Departments of Pharmacology and Neurosciences, UCSD School of Medicine, La Jolla, CA, USA
| | - SM Azarian
- Departments of Pharmacology and Neurosciences, UCSD School of Medicine, La Jolla, CA, USA
| | - E Legacki
- Departments of Pharmacology and Neurosciences, UCSD School of Medicine, La Jolla, CA, USA
| | - X-M Zhang
- Jules Stein Eye Institute, Molecular Biology Institute, UCLA School of Medicine, Los Angeles, CA, USA
| | - X-J Yang
- Jules Stein Eye Institute, Molecular Biology Institute, UCLA School of Medicine, Los Angeles, CA, USA
| | - DS Williams
- Departments of Pharmacology and Neurosciences, UCSD School of Medicine, La Jolla, CA, USA
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Jaijo T, Aller E, Beneyto M, Nájera C, Millán JM. Estudio genético molecular del síndrome de Usher en España. Acta Otorrinolaringológica Española 2005; 56:285-9. [PMID: 16240916 DOI: 10.1016/s0001-6519(05)78616-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Usher syndrome (USH) associates deafness and retinitis pigmentosa (RP). It is a disease both clinically and genetically heterogeneous. It is inherited as an autosomal recessive trait and its prevalence makes it the most frequent association of hearing loss and RP. Clinically Usher syndrome is divided into type I (USH1), II (USH2) and III (USH3), according to the severity of hearing loss, age of onset of RP and the existence or not of vestibular dysfunction. There are at least 7 different localizations for USH1 and 5 genes have been identified. For USH2, 3 loci and 2 genes have been reported and USH3 is due to Clarin-1 gene. Our aim is to perform a clinical and genetic characterization of all Usher syndrome patients in Spain.
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Affiliation(s)
- T Jaijo
- Unidad de Genetica, Hospital Universitario La Fe, Valencia
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