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Daich Varela M, Georgiadis A, Michaelides M. Genetic treatment for autosomal dominant inherited retinal dystrophies: approaches, challenges and targeted genotypes. Br J Ophthalmol 2023; 107:1223-1230. [PMID: 36038193 DOI: 10.1136/bjo-2022-321903] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/01/2022] [Indexed: 11/04/2022]
Abstract
Inherited retinal diseases (IRDs) have been in the front line of gene therapy development for the last decade, providing a useful platform to test novel therapeutic approaches. More than 40 clinical trials have been completed or are ongoing, tackling autosomal recessive and X-linked conditions, mostly through adeno-associated viral vector delivery of a normal copy of the disease-causing gene. However, only recently has autosomal dominant (ad) disease been targeted, with the commencement of a trial for rhodopsin (RHO)-associated retinitis pigmentosa (RP), implementing antisense oligonucleotide (AON) therapy, with promising preliminary results (NCT04123626).Autosomal dominant RP represents 15%-25% of all RP, with RHO accounting for 20%-30% of these cases. Autosomal dominant macular and cone-rod dystrophies (MD/CORD) correspond to approximately 7.5% of all IRDs, and approximately 35% of all MD/CORD cases, with the main causative gene being BEST1 Autosomal dominant IRDs are not only less frequent than recessive, but also tend to be less severe and have later onset; for example, an individual with RHO-adRP would typically become severely visually impaired at an age 2-3 times older than in X-linked RPGR-RP.Gain-of-function and dominant negative aetiologies are frequently seen in the prevalent adRP genes RHO, RP1 and PRPF31 among others, which would not be effectively addressed by gene supplementation alone and need creative, novel approaches. Zinc fingers, RNA interference, AON, translational read-through therapy, and gene editing by clustered regularly interspaced short palindromic repeats/Cas are some of the strategies that are currently under investigation and will be discussed here.
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Affiliation(s)
- Malena Daich Varela
- Moorfields Eye Hospital, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
| | | | - Michel Michaelides
- Moorfields Eye Hospital, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
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2
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Sp S, Mitra RN, Zheng M, Chrispell JD, Wang K, Kwon YS, Weiss ER, Han Z. Gene augmentation for autosomal dominant retinitis pigmentosa using rhodopsin genomic loci nanoparticles in the P23H +/- knock-in murine model. Gene Ther 2023; 30:628-640. [PMID: 36935427 DOI: 10.1038/s41434-023-00394-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 02/13/2023] [Accepted: 02/28/2023] [Indexed: 03/21/2023]
Abstract
Gene therapy for autosomal dominant retinitis pigmentosa (adRP) is challenged by the dominant inheritance of the mutant genes, which would seemingly require a combination of mutant suppression and wild-type replacement of the appropriate gene. We explore the possibility that delivery of a nanoparticle (NP)-mediated full-length mouse genomic rhodopsin (gRho) or human genomic rhodopsin (gRHO) locus can overcome the dominant negative effects of the mutant rhodopsin in the clinically relevant P23H+/--knock-in heterozygous mouse model. Our results demonstrate that mice in both gRho and gRHO NP-treated groups exhibit significant structural and functional recovery of the rod photoreceptors, which lasted for 3 months post-injection, indicating a promising reduction in photoreceptor degeneration. We performed miRNA transcriptome analysis using next generation sequencing and detected differentially expressed miRNAs as a first step towards identifying miRNAs that could potentially be used as rhodopsin gene expression enhancers or suppressors for sustained photoreceptor rescue. Our results indicate that delivering an intact genomic locus as a transgene has a greater chance of success compared to the use of the cDNA for treatment of this model of adRP, emphasizing the importance of gene augmentation using a gDNA that includes regulatory elements.
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Affiliation(s)
- Simna Sp
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Rajendra N Mitra
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Min Zheng
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jared D Chrispell
- Department of Cell Biology and Physiology, the University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Kai Wang
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Yong-Su Kwon
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Ellen R Weiss
- Department of Cell Biology and Physiology, the University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Zongchao Han
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Carolina Institute for NanoMedicine, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Division of Pharmacoengineering & Molecular Pharmaceutics, Eshelman School of Pharmacy, the University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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3
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Ahmed CM, Massengill MT, Ildefonso CJ, Jalligampala A, Zhu P, Li H, Patel AP, McCall MA, Lewin AS. Binocular benefit following monocular subretinal AAV injection in a mouse model of autosomal dominant retinitis pigmentosa (adRP). Vision Res 2023; 206:108189. [PMID: 36773475 DOI: 10.1016/j.visres.2023.108189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/05/2023] [Accepted: 01/05/2023] [Indexed: 02/11/2023]
Abstract
Autosomal dominant retinitis pigmentosa (adRP) is frequently caused by mutations in RHO, the gene for rhodopsin. In previous experiments in dogs with the T4R mutation in RHO, an AAV2/5 vector expressing an shRNA directed to human and dog RHO mRNA and an shRNA-resistant human RHO cDNA (AAV-RHO820-shRNA820) prevented retinal degeneration for more than eight months following injection. It is crucial, however, to determine if this RNA replacement vector acts in a mutation-independent and species-independent manner. We, therefore, injected mice transgenic for human P23H RHO with this vector unilaterally at postnatal day 30. We monitored their retinal structure by using spectral-domain optical coherence tomography (SD-OCT) and retinal function using electroretinography (ERG) for nine months. We compared these to P23H RHO transgenic mice injected unilaterally with a control vector. Though retinas continued to thin over time, compared to control injected eyes, treatment with AAV-RHO820-shRNA820 slowed the loss of photoreceptor cells and the decrease in ERG amplitudes during the nine-month study period. Unexpectedly, we also observed the preservation of retinal structure and function in the untreated contralateral eyes of AAV-RHO820-shRNA820 treated mice. PCR analysis and western blots showed that a low amount of vector from injected eyes was present in uninjected eyes. In addition, protective neurotrophic factors bFGF and GDNF were elevated in both eyes of treated mice. Our finding suggests that using this or similar RNA replacement vectors in human gene therapy may provide clinical benefit to both eyes of patients with adRP.
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Affiliation(s)
- Chulbul M Ahmed
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Michael T Massengill
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | | | - Archana Jalligampala
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA
| | - Ping Zhu
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Hong Li
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Anil P Patel
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Maureen A McCall
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA.
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4
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RNA-targeting strategies as a platform for ocular gene therapy. Prog Retin Eye Res 2023; 92:101110. [PMID: 35840489 DOI: 10.1016/j.preteyeres.2022.101110] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/28/2022] [Accepted: 07/06/2022] [Indexed: 02/01/2023]
Abstract
Genetic medicine is offering hope as new therapies are emerging for many previously untreatable diseases. The eye is at the forefront of these advances, as exemplified by the approval of Luxturna® by the United States Food and Drug Administration (US FDA) in 2017 for the treatment of one form of Leber Congenital Amaurosis (LCA), an inherited blindness. Luxturna® was also the first in vivo human gene therapy to gain US FDA approval. Numerous gene therapy clinical trials are ongoing for other eye diseases, and novel delivery systems, discovery of new drug targets and emerging technologies are currently driving the field forward. Targeting RNA, in particular, is an attractive therapeutic strategy for genetic disease that may have safety advantages over alternative approaches by avoiding permanent changes in the genome. In this regard, antisense oligonucleotides (ASO) and RNA interference (RNAi) are the currently popular strategies for developing RNA-targeted therapeutics. Enthusiasm has been further fuelled by the emergence of clustered regularly interspersed short palindromic repeats (CRISPR)-CRISPR associated (Cas) systems that allow targeted manipulation of nucleic acids. RNA-targeting CRISPR-Cas systems now provide a novel way to develop RNA-targeted therapeutics and may provide superior efficiency and specificity to existing technologies. In addition, RNA base editing technologies using CRISPR-Cas and other modalities also enable precise alteration of single nucleotides. In this review, we showcase advances made by RNA-targeting systems for ocular disease, discuss applications of ASO and RNAi technologies, highlight emerging CRISPR-Cas systems and consider the implications of RNA-targeting therapeutics in the development of future drugs to treat eye disease.
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Lewin AS, Smith WC. Gene Therapy for Rhodopsin Mutations. Cold Spring Harb Perspect Med 2022; 12:a041283. [PMID: 35940643 PMCID: PMC9435570 DOI: 10.1101/cshperspect.a041283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mutations in RHO, the gene for rhodopsin, account for a large fraction of autosomal-dominant retinitis pigmentosa (adRP). Patients fall into two clinical classes, those with early onset, pan retinal photoreceptor degeneration, and those who experience slowly progressive disease. The latter class of patients are candidates for photoreceptor-directed gene therapy, while former may be candidates for delivery of light-responsive proteins to interneurons or retinal ganglion cells. Gene therapy for RHO adRP may be targeted to the mutant gene at the DNA or RNA level, while other therapies preserve the viability of photoreceptors without addressing the underlying mutation. Correcting the RHO gene and replacing the mutant RNA show promise in animal models, while sustaining viable photoreceptors has the potential to delay the loss of central vision and may preserve photoreceptors for gene-directed treatments.
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Affiliation(s)
- Alfred S Lewin
- Departments of Molecular Genetics and Microbiology and Ophthalmology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
| | - W Clay Smith
- Departments of Molecular Genetics and Microbiology and Ophthalmology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
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Wu WH, Tsai YT, Huang IW, Cheng CH, Hsu CW, Cui X, Ryu J, Quinn PMJ, Caruso SM, Lin CS, Tsang SH. CRISPR genome surgery in a novel humanized model for autosomal dominant retinitis pigmentosa. Mol Ther 2022; 30:1407-1420. [PMID: 35150888 PMCID: PMC9077379 DOI: 10.1016/j.ymthe.2022.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 01/27/2022] [Accepted: 02/07/2022] [Indexed: 11/21/2022] Open
Abstract
Mutations in rhodopsin (RHO) are the most common causes of autosomal dominant retinitis pigmentosa (adRP), accounting for 20% to 30% of all cases worldwide. However, the high degree of genetic heterogeneity makes development of effective therapies cumbersome. To provide a universal solution to RHO-related adRP, we devised a CRISPR-based, mutation-independent gene ablation and replacement (AR) compound therapy carried by a dual AAV2/8 system. Moreover, we developed a novel hRHOC110R/hRHOWT humanized mouse model to assess the AR treatment in vivo. Results show that this humanized RHO mouse model exhibits progressive rod-cone degeneration that phenocopies hRHOC110R/hRHOWT patients. In vivo transduction of AR AAV8 dual vectors remarkably ablates endogenous RHO expression and overexpresses exogenous WT hRHO. Furthermore, the administration of AR during adulthood significantly hampers photoreceptor degeneration both histologically and functionally for at least 6 months compared with sole gene replacement or surgical trauma control. This study demonstrates the effectiveness of AR treatment of adRP in the human genomic context while revealing the feasibility of its application for other autosomal dominant disorders.
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Affiliation(s)
- Wen-Hsuan Wu
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA
| | - Yi-Ting Tsai
- Department of Biomedical Engineering, Columbia University, New York, NY 10032, USA
| | - I-Wen Huang
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA
| | - Chia-Hua Cheng
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA
| | - Chun-Wei Hsu
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA
| | - Xuan Cui
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA
| | - Joseph Ryu
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA
| | - Peter M J Quinn
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA
| | | | - Chyuang-Sheng Lin
- Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care and the Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA; Edward S. Harkness Eye Institute, New York-Presbyterian Hospital/Columbia University Medical Center, New York, NY 10032, USA; Department of Biomedical Engineering, Columbia University, New York, NY 10032, USA; Department of Pathology & Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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7
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Srivastava V, Singh A, Jain GK, Ahmad FJ, Shukla R, Kesharwani P. Viral vectors as a promising nanotherapeutic approach against neurodegenerative disorders. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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8
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Massengill MT, Lewin AS. Gene Therapy for Rhodopsin-associated Autosomal Dominant Retinitis Pigmentosa. Int Ophthalmol Clin 2021; 61:79-96. [PMID: 34584046 PMCID: PMC8478325 DOI: 10.1097/iio.0000000000000383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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9
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Zhu P, Dyka F, Ma X, Yin L, Yu H, Baehr W, Hauswirth WW, Deng WT. Disease mechanisms of X-linked cone dystrophy caused by missense mutations in the red and green cone opsins. FASEB J 2021; 35:e21927. [PMID: 34547123 PMCID: PMC8462070 DOI: 10.1096/fj.202101066r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/12/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022]
Abstract
Cone photoreceptors are responsible for the visual acuity and color vision of the human eye. Red/green cone opsin missense mutations N94K, W177R, P307L, R330Q, and G338E have been identified in subjects with congenital blue cone monochromacy or color‐vision deficiency. Studies on disease mechanisms due to these cone opsin mutations have been previously carried out exclusively in vitro, and the reported impairments were not always consistent. Here we expressed these mutants via AAV specifically in vivo in M‐opsin knockout mouse cones to investigate their subcellular localization, the pathogenic effects on cone structure, function, and cone viability. We show that these mutations alter the M‐opsin structure, function, and localization. N94K and W177R mutants appeared to be misfolded since they localized exclusively in cone inner segments and endoplasmic reticulum. In contrast, P307L, R330Q, and G338E mutants were detected predominately in cone outer segments. Expression of R330Q and G338E, but not P307L opsins, also partially restored expression and correct localization of cone PDE6α’ and cone transducin γ and resulted in partial rescue of M‐cone‐mediated light responses. Expression of W177R and P307L mutants significantly reduced cone viability, whereas N94K, R330Q, and G338E were only modestly toxic. We propose that although the underlying biochemical and cellular defects caused by these mutants are distinct, they all seem to exhibit a dominant phenotype, resembling autosomal dominant retinitis pigmentosa associated with the majority of rhodopsin missense mutations. The understanding of the molecular mechanisms associated with these cone opsin mutants is fundamental to developing targeted therapies for cone dystrophy/dysfunction.
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Affiliation(s)
- Ping Zhu
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Frank Dyka
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Xiaojie Ma
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Ling Yin
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Heather Yu
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Wolfgang Baehr
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, Utah, USA.,Department of Neurobiology and Anatomy, University of Utah Health Science Center, Salt Lake City, Utah, USA.,Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Wen-Tao Deng
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
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10
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Mirtron-mediated RNA knockdown/replacement therapy for the treatment of dominant retinitis pigmentosa. Nat Commun 2021; 12:4934. [PMID: 34400638 PMCID: PMC8368061 DOI: 10.1038/s41467-021-25204-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 07/26/2021] [Indexed: 02/07/2023] Open
Abstract
Rhodopsin (RHO) gene mutations are a common cause of autosomal dominant retinitis pigmentosa (ADRP). The need to suppress toxic protein expression together with mutational heterogeneity pose challenges for treatment development. Mirtrons are atypical RNA interference effectors that are spliced from transcripts as short introns. Here, we develop a novel mirtron-based knockdown/replacement gene therapy for the mutation-independent treatment of RHO-related ADRP, and demonstrate efficacy in a relevant mammalian model. Splicing and potency of rhodopsin-targeting candidate mirtrons are initially determined, and a mirtron-resistant codon-modified version of the rhodopsin coding sequence is validated in vitro. These elements are then combined within a single adeno-associated virus (AAV) and delivered subretinally in a RhoP23H knock-in mouse model of ADRP. This results in significant mouse-to-human rhodopsin RNA replacement and is associated with a slowing of retinal degeneration. This provides proof of principle that synthetic mirtrons delivered by AAV are capable of reducing disease severity in vivo.
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11
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Botto C, Rucli M, Tekinsoy MD, Pulman J, Sahel JA, Dalkara D. Early and late stage gene therapy interventions for inherited retinal degenerations. Prog Retin Eye Res 2021; 86:100975. [PMID: 34058340 DOI: 10.1016/j.preteyeres.2021.100975] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/18/2021] [Accepted: 05/21/2021] [Indexed: 12/12/2022]
Abstract
Inherited and age-related retinal degeneration is the hallmark of a large group of heterogeneous diseases and is the main cause of untreatable blindness today. Genetic factors play a major pathogenic role in retinal degenerations for both monogenic diseases (such as retinitis pigmentosa) and complex diseases with established genetic risk factors (such as age-related macular degeneration). Progress in genotyping techniques and back of the eye imaging are completing our understanding of these diseases and their manifestations in patient populations suffering from retinal degenerations. It is clear that whatever the genetic cause, the majority of vision loss in retinal diseases results from the loss of photoreceptor function. The timing and circumstances surrounding the loss of photoreceptor function determine the adequate therapeutic approach to use for each patient. Among such approaches, gene therapy is rapidly becoming a therapeutic reality applicable in the clinic. This massive move from laboratory work towards clinical application has been propelled by the advances in our understanding of disease genetics and mechanisms, gene delivery vectors, gene editing systems, and compensatory strategies for loss of photoreceptor function. Here, we provide an overview of existing modalities of retinal gene therapy and their relevance based on the needs of patient populations suffering from inherited retinal degenerations.
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Affiliation(s)
- Catherine Botto
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Marco Rucli
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Müge Defne Tekinsoy
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Juliette Pulman
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France; Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, United States; CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, F-75012, Paris, France; Fondation Ophtalmologique Rothschild, F-75019, Paris, France
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France.
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Orlans HO, Barnard AR, Patrício MI, McClements ME, MacLaren RE. Effect of AAV-Mediated Rhodopsin Gene Augmentation on Retinal Degeneration Caused by the Dominant P23H Rhodopsin Mutation in a Knock-In Murine Model. Hum Gene Ther 2020; 31:730-742. [DOI: 10.1089/hum.2020.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Harry O. Orlans
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
| | - Maria I. Patrício
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
| | | | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
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13
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Gorbatyuk MS, Starr CR, Gorbatyuk OS. Endoplasmic reticulum stress: New insights into the pathogenesis and treatment of retinal degenerative diseases. Prog Retin Eye Res 2020; 79:100860. [PMID: 32272207 DOI: 10.1016/j.preteyeres.2020.100860] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/08/2020] [Accepted: 03/17/2020] [Indexed: 12/13/2022]
Abstract
Physiological equilibrium in the retina depends on coordinated work between rod and cone photoreceptors and can be compromised by the expression of mutant proteins leading to inherited retinal degeneration (IRD). IRD is a diverse group of retinal dystrophies with multifaceted molecular mechanisms that are not fully understood. In this review, we focus on the contribution of chronically activated unfolded protein response (UPR) to inherited retinal pathogenesis, placing special emphasis on studies employing genetically modified animal models. As constitutively active UPR in degenerating retinas may activate pro-apoptotic programs associated with oxidative stress, pro-inflammatory signaling, dysfunctional autophagy, free cytosolic Ca2+ overload, and altered protein synthesis rate in the retina, we focus on the regulatory mechanisms of translational attenuation and approaches to overcoming translational attenuation in degenerating retinas. We also discuss current research on the role of the UPR mediator PERK and its downstream targets in degenerating retinas and highlight the therapeutic benefits of reprogramming PERK signaling in preclinical animal models of IRD. Finally, we describe pharmacological approaches targeting UPR in ocular diseases and consider their potential applications to IRD.
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Affiliation(s)
- Marina S Gorbatyuk
- The University of Alabama at Birmingham, Department of Optometry and Vision Science, School of Optometry, USA.
| | - Christopher R Starr
- The University of Alabama at Birmingham, Department of Optometry and Vision Science, School of Optometry, USA
| | - Oleg S Gorbatyuk
- The University of Alabama at Birmingham, Department of Optometry and Vision Science, School of Optometry, USA
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14
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Tebbe L, Kakakhel M, Makia MS, Al-Ubaidi MR, Naash MI. The Interplay between Peripherin 2 Complex Formation and Degenerative Retinal Diseases. Cells 2020; 9:E784. [PMID: 32213850 PMCID: PMC7140794 DOI: 10.3390/cells9030784] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/11/2020] [Accepted: 03/20/2020] [Indexed: 12/17/2022] Open
Abstract
Peripherin 2 (Prph2) is a photoreceptor-specific tetraspanin protein present in the outer segment (OS) rims of rod and cone photoreceptors. It shares many common features with other tetraspanins, including a large intradiscal loop which contains several cysteines. This loop enables Prph2 to associate with itself to form homo-oligomers or with its homologue, rod outer segment membrane protein 1 (Rom1) to form hetero-tetramers and hetero-octamers. Mutations in PRPH2 cause a multitude of retinal diseases including autosomal dominant retinitis pigmentosa (RP) or cone dominant macular dystrophies. The importance of Prph2 for photoreceptor development, maintenance and function is underscored by the fact that its absence results in a failure to initialize OS formation in rods and formation of severely disorganized OS membranous structures in cones. Although the exact role of Rom1 has not been well studied, it has been concluded that it is not necessary for disc morphogenesis but is required for fine tuning OS disc size and structure. Pathogenic mutations in PRPH2 often result in complex and multifactorial phenotypes, involving not just photoreceptors, as has historically been reasoned, but also secondary effects on the retinal pigment epithelium (RPE) and retinal/choroidal vasculature. The ability of Prph2 to form complexes was identified as a key requirement for the development and maintenance of OS structure and function. Studies using mouse models of pathogenic Prph2 mutations established a connection between changes in complex formation and disease phenotypes. Although progress has been made in the development of therapeutic approaches for retinal diseases in general, the highly complex interplay of functions mediated by Prph2 and the precise regulation of these complexes made it difficult, thus far, to develop a suitable Prph2-specific therapy. Here we describe the latest results obtained in Prph2-associated research and how mouse models provided new insights into the pathogenesis of its related diseases. Furthermore, we give an overview on the current status of the development of therapeutic solutions.
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Affiliation(s)
| | | | | | - Muayyad R. Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA; (L.T.); (M.K.); (M.S.M.)
| | - Muna I. Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA; (L.T.); (M.K.); (M.S.M.)
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15
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Calabro KR, Boye SL, Choudhury S, Fajardo D, Peterson JJ, Li W, Crosson SM, Kim MJ, Ding D, Salvi R, Someya S, Boye SE. A Novel Mouse Model of MYO7A USH1B Reveals Auditory and Visual System Haploinsufficiencies. Front Neurosci 2019; 13:1255. [PMID: 31824252 PMCID: PMC6883748 DOI: 10.3389/fnins.2019.01255] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 11/05/2019] [Indexed: 12/20/2022] Open
Abstract
Usher’s syndrome is the most common combined blindness–deafness disorder with USH1B, caused by mutations in MYO7A, resulting in the most severe phenotype. The existence of numerous, naturally occurring shaker1 mice harboring variable MYO7A mutations on different genetic backgrounds has complicated the characterization of MYO7A knockout (KO) and heterozygote mice. We generated a novel MYO7A KO mouse (Myo7a–/–) that is easily genotyped, maintained, and confirmed to be null for MYO7A in both the eye and inner ear. Like USH1B patients, Myo7a–/– mice are profoundly deaf, and display near complete loss of inner and outer cochlear hair cells (HCs). No gross structural changes were observed in vestibular HCs. Myo7a–/– mice exhibited modest declines in retinal function but, unlike patients, no loss of retinal structure. We attribute the latter to differential expression of MYO7A in mouse vs. primate retina. Interestingly, heterozygous Myo7a+/– mice had reduced numbers of cochlear HCs and concomitant reductions in auditory function relative to Myo7a+/+ controls. Notably, this is the first report that loss of a single Myo7a allele significantly alters auditory structure and function and suggests that audiological characterization of USH1B carriers is warranted. Maintenance of vestibular HCs in Myo7a–/– mice suggests that gene replacement could be used to correct the vestibular dysfunction in USH1B patients. While Myo7a–/– mice do not exhibit sufficiently robust retinal phenotypes to be used as a therapeutic outcome measure, they can be used to assess expression of vectored MYO7A on a null background and generate valuable pre-clinical data toward the treatment of USH1B.
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Affiliation(s)
- Kaitlyn R Calabro
- Department of Ophthalmology, University of Florida, Gainesville, FL, United States
| | - Sanford L Boye
- Department of Pediatrics, University of Florida, Gainesville, FL, United States
| | - Shreyasi Choudhury
- Department of Ophthalmology, University of Florida, Gainesville, FL, United States
| | - Diego Fajardo
- Department of Ophthalmology, University of Florida, Gainesville, FL, United States
| | - James J Peterson
- Department of Ophthalmology, University of Florida, Gainesville, FL, United States
| | - Wei Li
- Department of Ophthalmology, University of Florida, Gainesville, FL, United States
| | - Sean M Crosson
- Department of Ophthalmology, University of Florida, Gainesville, FL, United States
| | - Mi-Jung Kim
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, United States
| | - Dalian Ding
- Department of Communicative Disorders and Sciences, The State University of New York at Buffalo, Buffalo NY, United States
| | - Richard Salvi
- Department of Communicative Disorders and Sciences, The State University of New York at Buffalo, Buffalo NY, United States
| | - Shinichi Someya
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, United States
| | - Shannon E Boye
- Department of Ophthalmology, University of Florida, Gainesville, FL, United States
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16
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Gene Therapy in Retinal Dystrophies. Int J Mol Sci 2019; 20:ijms20225722. [PMID: 31739639 PMCID: PMC6888000 DOI: 10.3390/ijms20225722] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/13/2019] [Accepted: 11/13/2019] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal dystrophies (IRDs) are a group of clinically and genetically heterogeneous degenerative disorders. To date, mutations have been associated with IRDs in over 270 disease genes, but molecular diagnosis still remains elusive in about a third of cases. The methodologic developments in genome sequencing techniques that we have witnessed in this last decade have represented a turning point not only in diagnosis and prognosis but, above all, in the identification of new therapeutic perspectives. The discovery of new disease genes and pathogenetic mechanisms underlying IRDs has laid the groundwork for gene therapy approaches. Several clinical trials are ongoing, and the recent approval of Luxturna, the first gene therapy product for Leber congenital amaurosis, marks the beginning of a new era. Due to its anatomical and functional characteristics, the retina is the organ of choice for gene therapy, although there are quite a few difficulties in the translational approaches from preclinical models to humans. In the first part of this review, an overview of the current knowledge on methodological issues and future perspectives of gene therapy applied to IRDs is discussed; in the second part, the state of the art of clinical trials on the gene therapy approach in IRDs is illustrated.
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17
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Song B, Kim D, Nguyen NH, Roy S. Inhibition of Diabetes-Induced Lysyl Oxidase Overexpression Prevents Retinal Vascular Lesions Associated With Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2019; 59:5965-5972. [PMID: 30550614 PMCID: PMC6295938 DOI: 10.1167/iovs.18-25543] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose The purpose of this study was to investigate the effect of reducing diabetes-induced lysyl oxidase (LOX) overexpression on vascular cell apoptosis and blood-retinal barrier (BRB) characteristics in diabetic rats. Methods Nondiabetic rats, diabetic rats, and diabetic rats intravitreally (IV) injected with LOX siRNA or scrambled (scram) siRNA were used in the study. One month after the onset of diabetes, intravitreal injections were initiated at monthly intervals for up to three times. At the end of study, retinal capillary networks were isolated, stained with periodic acid-Schiff (PAS) and hematoxylin, and assessed for acellular capillaries (AC) and pericyte loss (PL). To assess vascular leakage, extravasation of FITC-dextran was evaluated in retinal capillaries after tail vein injection of FITC-dextran. Western blot analysis was performed to determine retinal LOX level and confirm LOX downregulation via LOX siRNA intravitreal injection. Results LOX expression was significantly upregulated in retinas of diabetic rats compared with that of nondiabetic rats. Diabetic rats injected with LOX siRNA showed a significant decrease in retinal LOX expression compared with those of diabetic rats or scram siRNA-injected rats. In diabetic retinas, AC and PL were significantly increased compared with those of nondiabetic retinas. Importantly, diabetic rats treated with LOX siRNA exhibited a significant decrease in AC and PL counts compared with those of untreated diabetic rats. Furthermore, diabetic rats treated with LOX siRNA showed significant decrease in retinal vascular permeability compared with that of untreated diabetic rats. Conclusions Findings suggest LOX siRNA intravitreal injection may be effective against diabetes-induced LOX overexpression in preventing apoptosis and vascular leakage associated with diabetic retinopathy.
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Affiliation(s)
- Brian Song
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States.,Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Dongjoon Kim
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States.,Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Ngan-Ha Nguyen
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States.,Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Sayon Roy
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States.,Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
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18
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Genome Editing as a Treatment for the Most Prevalent Causative Genes of Autosomal Dominant Retinitis Pigmentosa. Int J Mol Sci 2019; 20:ijms20102542. [PMID: 31126147 PMCID: PMC6567127 DOI: 10.3390/ijms20102542] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/15/2019] [Accepted: 05/22/2019] [Indexed: 02/07/2023] Open
Abstract
: Inherited retinal dystrophies (IRDs) are a clinically and genetically heterogeneous group of diseases with more than 250 causative genes. The most common form is retinitis pigmentosa. IRDs lead to vision impairment for which there is no universal cure. Encouragingly, a first gene supplementation therapy has been approved for an autosomal recessive IRD. However, for autosomal dominant IRDs, gene supplementation therapy is not always pertinent because haploinsufficiency is not the only cause. Disease-causing mechanisms are often gain-of-function or dominant-negative, which usually require alternative therapeutic approaches. In such cases, genome-editing technology has raised hopes for treatment. Genome editing could be used to i) invalidate both alleles, followed by supplementation of the wild type gene, ii) specifically invalidate the mutant allele, with or without gene supplementation, or iii) to correct the mutant allele. We review here the most prevalent genes causing autosomal dominant retinitis pigmentosa and the most appropriate genome-editing strategy that could be used to target their different causative mutations.
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Massengill MT, Young B, Patel D, Jafri F, Sabogal E, Ash N, Li H, Ildefonso CJ, Lewin AS. Clinically Relevant Outcome Measures for the I307N Rhodopsin Mouse: A Model of Inducible Autosomal Dominant Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2019; 59:5417-5430. [PMID: 30452595 PMCID: PMC6237214 DOI: 10.1167/iovs.18-25345] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Purpose The I307N rhodopsin (Rho) mouse is a light-inducible model of autosomal dominant retinitis pigmentosa (adRP) that may be useful in testing therapies. We investigated the time-course of retinal changes of the I307N Rho mouse with spectral-domain optical coherence tomography (SD-OCT). Methods SD-OCT was performed up to day 30 after light damage; electroretinography (ERG) was employed to evaluate photoreceptor function. We utilized ImageJ to analyze reflectivity of the retina. We used light and electron microscopy to assess retinal organization. We stained synaptophysin and zonula occludins-1 with immunohistochemistry to determine injury to the plexiform layers and retinal pigment epithelium (RPE). We performed lectin staining to evaluate retinal blood vessels. Results Retinal degeneration increased with longer exposures to light. An increase in retinal thickness was detected by SD-OCT on day 1 after light challenge followed by loss of the outer nuclear layer (ONL) by day 8. Degeneration was most severe in the nasal and inferior retina. Hyper-reflectivity on SD-OCT developed as early as 1 day after light exposure. Disorganization of the ONL, condensation of photoreceptor chromatin, disruption of the outer limiting membrane, and disarray of outer segments were associated with the hyper-reflectivity. Retraction of the outer plexiform synapses and resorption of the subretinal detachment contributed to retinal thinning. The RPE remained intact, whereas atrophied major retinal vessels were evident after light damage. Conclusions Our time-course analysis of retinal degeneration in the I307N Rho mouse with SD-OCT and other outcome measures should enable the use of the mouse model in preclinical efficacy studies and mechanistic studies.
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Affiliation(s)
- Michael T Massengill
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Brianna Young
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Deep Patel
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Farwa Jafri
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Ernesto Sabogal
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Neil Ash
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Hong Li
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Cristhian J Ildefonso
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
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20
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Fundus autofluorescence and ellipsoid zone (EZ) line width can be an outcome measurement in RHO-associated autosomal dominant retinitis pigmentosa. Graefes Arch Clin Exp Ophthalmol 2019; 257:725-731. [PMID: 30635721 DOI: 10.1007/s00417-018-04234-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 12/17/2018] [Accepted: 12/31/2018] [Indexed: 10/27/2022] Open
Abstract
PURPOSE To evaluate the progression of retinitis pigmentosa (RP) due to mutations in rhodopsin (RHO) by measuring the short-wavelength autofluorescence (SW-AF) increased autofluorescence ring and ellipsoid zone (EZ)-line width. METHODS Fundus autofluorescence (FAF) and spectral domain optical coherence tomography (SD-OCT) images were obtained from 10 patients with autosomal dominant RP due to mutations in the RHO gene. Measurements of ring area on FAF images, as well as the EZ line width on SD-OCT images and horizontal, vertical diameter, were performed by two independent masked graders. RESULTS The ring area decreased by a rate of 0.6 ± 0.2 mm2 per year. We observed that the EZ line width decreased by an average of 152 ± 37 μm per year, while the horizontal and vertical diameters decreased by 106 ± 35 μm and 125 ± 29 μm per year, respectively. Progression rates were similar between eyes. CONCLUSIONS We observed SW-AF ring constriction and a progressive loss of EZ line width over time.
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21
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Massengill MT, Young BM, Lewin AS, Ildefonso CJ. Co-Delivery of a Short-Hairpin RNA and a shRNA-Resistant Replacement Gene with Adeno-Associated Virus: An Allele-Independent Strategy for Autosomal-Dominant Retinal Disorders. Methods Mol Biol 2019; 1937:235-258. [PMID: 30706401 DOI: 10.1007/978-1-4939-9065-8_15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recombinant adeno-associated virus (rAAV) has become an important gene delivery vector for the treatment of inherited retinal degenerative diseases. Many of the mutations leading to retinal degeneration are inherited in an autosomal-dominant pattern and can produce toxic gain-of-function and/or dominant-negative effects. Here we describe an allele-independent gene therapy strategy with rAAV to treat autosomal-dominant retinal degenerative diseases. In this methodology, we co-deliver a short-hairpin RNA (shRNA) to inhibit expression of both the toxic and (WT) copies of the gene as well as an shRNA-resistant cDNA for functional gene replacement with a rAAV.
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Affiliation(s)
- Michael T Massengill
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Brianna M Young
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Cristhian J Ildefonso
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA.
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA.
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22
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Progress in Gene Therapy for Rhodopsin Autosomal Dominant Retinitis Pigmentosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1185:113-118. [PMID: 31884598 DOI: 10.1007/978-3-030-27378-1_19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This brief review summarizes the major proof-of-concept gene therapy studies for autosomal dominant retinitis pigmentosa (RP) caused by mutations in the rhodopsin gene (RHO-adRP) that have been conducted over the past 20 years in various animal models. We have listed in tabular form the various approaches, gene silencing reagents, gene delivery strategies, and salient results from these studies.
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Xiong YQ, Zhang MY, Zhou JH, Li YZ, You FF, Wen YQ, He WQ, Chen Q. A Molecular Epidemiological Investigation of Carriage of the Adeno-Associated Virus in Murine Rodents and House Shrews in China. Intervirology 2018; 61:143-148. [PMID: 30404084 DOI: 10.1159/000493799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/16/2018] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To investigate the prevalence of the adeno-associated virus (AAV) in murine rodents and house shrews in 4 provinces of China. METHODS A total of 469 murine rodents and 19 house shrews were captured between May 2015 and May 2017. Cap gene of AAV sequences was obtained to evaluate the genetic characteristics of rat AAV. RESULTS Rat AAVs were found in 54.7% (267/488) of throat swabs, 14.3% (70/488) of fecal samples, and 18.4% (41/223) of serum samples. Rat AAVs were detected in 3 species of murine rodents including Rattus norvegicus (34.8%), R. tanezumi (43.0%), and R. losea (2.3%), and house shrews (Suncus murinus) (26.1%) from the selected sampling sites. Fourteen near-full-length Cap gene sequences, ranging in length from 2,156 to 2,169 nt, were isolated from the fecal samples of R. norvegicus and R. tanezumi. These 14 sequences shared a high identity of 97.4% at the nucleotide level and 99.1% at the amino acid level. Phylogenetic analysis showed that the rat AAV formed a distinct clade, distinguishable from the AAV discovered in humans and in other animals. CONCLUSIONS A high prevalence of rat AAV that was highly conserved within the Cap gene was found in 3 common murine rodents and house shrews in China.
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Affiliation(s)
- Yi-Quan Xiong
- Department of Epidemiology, School of Public Health, Guangdong Provincial Key Laboratory of Tropical Disease Research, Southern Medical University, Guangzhou, China
| | - Min-Yi Zhang
- Department of Epidemiology, School of Public Health, Guangdong Provincial Key Laboratory of Tropical Disease Research, Southern Medical University, Guangzhou, China
| | - Jun-Hua Zhou
- Department of Epidemiology, Medical College of Hunan Normal University, Changsha, China
| | - Yong-Zhi Li
- Department of Epidemiology, School of Public Health, Guangdong Provincial Key Laboratory of Tropical Disease Research, Southern Medical University, Guangzhou, China
| | - Fang-Fei You
- Department of Epidemiology, School of Public Health, Guangdong Provincial Key Laboratory of Tropical Disease Research, Southern Medical University, Guangzhou, China
| | - Yu-Qi Wen
- Department of Epidemiology, School of Public Health, Guangdong Provincial Key Laboratory of Tropical Disease Research, Southern Medical University, Guangzhou, China
| | - Wen-Qiao He
- Department of Epidemiology, School of Public Health, Guangdong Provincial Key Laboratory of Tropical Disease Research, Southern Medical University, Guangzhou, China
| | - Qing Chen
- Department of Epidemiology, School of Public Health, Guangdong Provincial Key Laboratory of Tropical Disease Research, Southern Medical University, Guangzhou, China,
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Khabou H, Cordeau C, Pacot L, Fisson S, Dalkara D. Dosage Thresholds and Influence of Transgene Cassette in Adeno-Associated Virus-Related Toxicity. Hum Gene Ther 2018; 29:1235-1241. [PMID: 30132368 DOI: 10.1089/hum.2018.144] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Today, there are >500 published studies and 40 clinical trials to treat retinal disorders using gene therapy. The great majority of them rely on the use of adeno-associated virus vectors (AAV) for therapeutic gene delivery. Thus far, AAVs have an excellent safety profile in the clinic. Nevertheless, it is known that AAV-mediated gene delivery leads to toxicity at higher input doses in experimental gene therapy. This study reveals the factors that contribute to retinal toxicity after subretinal administration of AAV vectors in wild-type mice. The study shows that alongside the input dose, the nature of the transgene and the cells mediating the expression determine the extent of toxicity. Importantly, the study shows that AAV vectors encoding green fluorescent protein (GFP) used as controls in experimental gene therapy are toxic at doses as low as 5 × 109 vg, confounding the observed therapeutic effect in gene therapy paradigms. Altogether, the data show the importance of reducing input doses while increasing transgene expression levels via the use of more efficient capsids and promoters in order to avoid side effects in AAV-mediated gene therapy. Furthermore, the toxicity observed with AAV-GFP vectors imply a reinterpretation of previous gene therapy studies where the therapeutic effect was measured in relation to this control.
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Affiliation(s)
- Hanen Khabou
- 1 Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision , Paris, France; and Inserm UMR_S951, Univ Evry, Université Paris-Saclay, EPHE, Evry, France
| | - Chloé Cordeau
- 1 Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision , Paris, France; and Inserm UMR_S951, Univ Evry, Université Paris-Saclay, EPHE, Evry, France
| | - Laure Pacot
- 1 Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision , Paris, France; and Inserm UMR_S951, Univ Evry, Université Paris-Saclay, EPHE, Evry, France
| | - Sylvain Fisson
- 2 Généthon, Inserm UMR_S951, Univ Evry, Université Paris-Saclay, EPHE, Evry, France
| | - Deniz Dalkara
- 1 Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision , Paris, France; and Inserm UMR_S951, Univ Evry, Université Paris-Saclay, EPHE, Evry, France
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25
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Tsai YT, Wu WH, Lee TT, Wu WP, Xu CL, Park KS, Cui X, Justus S, Lin CS, Jauregui R, Su PY, Tsang SH. Clustered Regularly Interspaced Short Palindromic Repeats-Based Genome Surgery for the Treatment of Autosomal Dominant Retinitis Pigmentosa. Ophthalmology 2018; 125:1421-1430. [PMID: 29759820 PMCID: PMC6109419 DOI: 10.1016/j.ophtha.2018.04.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/29/2018] [Accepted: 04/02/2018] [Indexed: 01/02/2023] Open
Abstract
PURPOSE To develop a universal gene therapy to overcome the genetic heterogeneity in retinitis pigmentosa (RP) resulting from mutations in rhodopsin (RHO). DESIGN Experimental study for a combination gene therapy that uses both gene ablation and gene replacement. PARTICIPANTS This study included 2 kinds of human RHO mutation knock-in mouse models: RhoP23H and RhoD190N. In total, 23 RhoP23H/P23H, 43 RhoP23H/+, and 31 RhoD190N/+ mice were used for analysis. METHODS This study involved gene therapy using dual adeno-associated viruses (AAVs) that (1) destroy expression of the endogenous Rho gene in a mutation-independent manner via an improved clustered regularly interspaced short palindromic repeats-based gene deletion and (2) enable expression of wild-type protein via exogenous cDNA. MAIN OUTCOME MEASURES Electroretinographic and histologic analysis. RESULTS The thickness of the outer nuclear layer (ONL) after the subretinal injection of combination ablate-and-replace gene therapy was approximately 17% to 36% more than the ONL thickness resulting from gene replacement-only therapy at 3 months after AAV injection. Furthermore, electroretinography results demonstrated that the a and b waves of both RhoP23H and RhoD190N disease models were preserved more significantly using ablate-and-replace gene therapy (P < 0.001), but not by gene replacement monotherapy. CONCLUSIONS As a proof of concept, our results suggest that the ablate-and-replace strategy can ameliorate disease progression as measured by photoreceptor structure and function for both of the human mutation knock-in models. These results demonstrate the potency of the ablate-and-replace strategy to treat RP caused by different Rho mutations. Furthermore, because ablate-and-replace treatment is mutation independent, this strategy may be used to treat a wide array of dominant diseases in ophthalmology and other fields. Clinical trials using ablate-and-replace gene therapy would allow researchers to determine if this strategy provides any benefits for patients with diseases of interest.
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Affiliation(s)
- Yi-Ting Tsai
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York; Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Wen-Hsuan Wu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Ting-Ting Lee
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Wei-Pu Wu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Christine L Xu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Karen S Park
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Xuan Cui
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Sally Justus
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Chyuan-Sheng Lin
- Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York
| | - Ruben Jauregui
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York; Weill Cornell Medical College, New York, New York
| | - Pei-Yin Su
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, New York; Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York; Department of Ophthalmology, Edward S. Harkness Eye Institute, New York Presbyterian Hospital, New York, New York.
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Mutation-independent rhodopsin gene therapy by knockdown and replacement with a single AAV vector. Proc Natl Acad Sci U S A 2018; 115:E8547-E8556. [PMID: 30127005 DOI: 10.1073/pnas.1805055115] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Inherited retinal degenerations are caused by mutations in >250 genes that affect photoreceptor cells or the retinal pigment epithelium and result in vision loss. For autosomal recessive and X-linked retinal degenerations, significant progress has been achieved in the field of gene therapy as evidenced by the growing number of clinical trials and the recent commercialization of the first gene therapy for a form of congenital blindness. However, despite significant efforts to develop a treatment for the most common form of autosomal dominant retinitis pigmentosa (adRP) caused by >150 mutations in the rhodopsin (RHO) gene, translation to the clinic has stalled. Here, we identified a highly efficient shRNA that targets human (and canine) RHO in a mutation-independent manner. In a single adeno-associated viral (AAV) vector we combined this shRNA with a human RHO replacement cDNA made resistant to RNA interference and tested this construct in a naturally occurring canine model of RHO-adRP. Subretinal vector injections led to nearly complete suppression of endogenous canine RHO RNA, while the human RHO replacement cDNA resulted in up to 30% of normal RHO protein levels. Noninvasive retinal imaging showed photoreceptors in treated areas were completely protected from retinal degeneration. Histopathology confirmed retention of normal photoreceptor structure and RHO expression in rod outer segments. Long-term (>8 mo) follow-up by retinal imaging and electroretinography indicated stable structural and functional preservation. The efficacy of this gene therapy in a clinically relevant large-animal model paves the way for treating patients with RHO-adRP.
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Giannelli SG, Luoni M, Castoldi V, Massimino L, Cabassi T, Angeloni D, Demontis GC, Leocani L, Andreazzoli M, Broccoli V. Cas9/sgRNA selective targeting of the P23H Rhodopsin mutant allele for treating retinitis pigmentosa by intravitreal AAV9.PHP.B-based delivery. Hum Mol Genet 2018; 27:761-779. [PMID: 29281027 DOI: 10.1093/hmg/ddx438] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 12/18/2017] [Indexed: 01/05/2024] Open
Abstract
P23H is the most common mutation in the RHODOPSIN (RHO) gene leading to a dominant form of retinitis pigmentosa (RP), a rod photoreceptor degeneration that invariably causes vision loss. Specific disruption of the disease P23H RHO mutant while preserving the wild-type (WT) functional allele would be an invaluable therapy for this disease. However, various technologies tested in the past failed to achieve effective changes and consequently therapeutic benefits. We validated a CRISPR/Cas9 strategy to specifically inactivate the P23H RHO mutant, while preserving the WT allele in vitro. We, then, translated this approach in vivo by delivering the CRISPR/Cas9 components in murine Rho+/P23H mutant retinae. Targeted retinae presented a high rate of cleavage in the P23H but not WT Rho allele. This gene manipulation was sufficient to slow photoreceptor degeneration and improve retinal functions. To improve the translational potential of our approach, we tested intravitreal delivery of this system by means of adeno-associated viruses (AAVs). To this purpose, the employment of the AAV9-PHP.B resulted the most effective in disrupting the P23H Rho mutant. Finally, this approach was translated successfully in human cells engineered with the homozygous P23H RHO gene mutation. Overall, this is a significant proof-of-concept that gene allele specific targeting by CRISPR/Cas9 technology is specific and efficient and represents an unprecedented tool for treating RP and more broadly dominant genetic human disorders affecting the eye, as well as other tissues.
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Affiliation(s)
- Serena G Giannelli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Mirko Luoni
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Valerio Castoldi
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Luca Massimino
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
- Institute of Neuroscience, National Research Council (CNR), 20129 Milan, Italy
| | - Tommaso Cabassi
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
- Institute of Neuroscience, National Research Council (CNR), 20129 Milan, Italy
| | - Debora Angeloni
- Institute of Life Sciences, Scuola Superiore Sant'Anna, 56124 Pisa, Italy
| | | | - Letizia Leocani
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE), San Raffaele Scientific Institute, 20132 Milan, Italy
| | | | - Vania Broccoli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
- Institute of Neuroscience, National Research Council (CNR), 20129 Milan, Italy
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Öner A. Recent Advancements in Gene Therapy for Hereditary Retinal Dystrophies. Turk J Ophthalmol 2017; 47:338-343. [PMID: 29326851 PMCID: PMC5758769 DOI: 10.4274/tjo.41017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 04/20/2017] [Indexed: 12/01/2022] Open
Abstract
Hereditary retinal dystrophies (HRDs) are degenerative diseases of the retina which have marked clinical and genetic heterogeneity. Common presentations among these disorders include night or colour blindness, tunnel vision, and subsequent progression to complete blindness. The known causative disease genes have a variety of developmental and functional roles, with mutations in more than 120 genes shown to be responsible for the phenotypes. In addition, mutations within the same gene have been shown to cause different disease phenotypes, even amongst affected individuals within the same family, highlighting further levels of complexity. The known disease genes encode proteins involved in retinal cellular structures, phototransduction, the visual cycle, and photoreceptor structure or gene regulation. Significant advancements have been made in understanding the genetic pathogenesis of ocular diseases, and gene replacement and gene silencing have been proposed as potentially efficacious therapies. Because of its favorable anatomical and immunological characteristics, the eye has been at the forefront of translational gene therapy. Recent improvements have been made in the safety and specificity of vector-based ocular gene transfer methods. Dozens of promising proofs of concept have been obtained in animal models of HRDs and some of them have been relayed to the clinic. The results from the first clinical trials for a congenital form of blindness have generated great interest and have demonstrated the safety and efficacy of intraocular administrations of viral vectors in humans. This review summarizes the clinical development of retinal gene therapy.
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Affiliation(s)
- Ayşe Öner
- Erciyes University Faculty of Medicine, Department of Ophthalmology, Kayseri, Turkey
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Ghaderi S, Ahmadian S, Soheili ZS, Ahmadieh H, Samiei S, Kheitan S, Pirmardan ER. AAV delivery of GRP78/BiP promotes adaptation of human RPE cell to ER stress. J Cell Biochem 2017; 119:1355-1367. [PMID: 28782832 DOI: 10.1002/jcb.26296] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/18/2017] [Indexed: 12/14/2022]
Abstract
Adeno associated virus (AAV)-mediated gene delivery of GRP78 (78 kDa glucose-regulated protein) attenuates the condition of endoplasmic reticulum (ER) stress and prevents apoptotic loss of photoreceptors in Retinitis pigmentosa (RP) rats. In the current study we overexpressed Grp78 with the help of AAV-2 in primary human retinal pigmented epithelium (hRPE) cell cultures and examined its effect on cell response to ER stress. The purpose of this work was studying potential stimulating effect of GRP78 on adaptation/pro-survival of hRPE cells under ER stress, as an in vitro model for RPE degeneration. To investigate the effect of Grp78 overexpression on unfolded protein response (UPR) markers under ER stress, hRPE primary cultures were transduced by recombinant virus rAAV/Grp78, and treated with ER stressor drug, tunicamycin. Expression changes of four UPR markers including GRP78, PERK, ATF6α, and GADD153/CHOP, were assessed by real-time PCR and western blotting. We found that GRP78 has a great contribution in modulation of UPR markers to favor adaptive response in ER-stressed hRPE cells. In fact, GRP78 overexpression affected adaptation and apoptotic phases of early UPR, through enhancement of two master regulators/ER stress sensors (PERK and ATF6α) and down-regulation of a key pro-apoptotic cascade activator (GADD153/CHOP). Together these findings demonstrate the promoting effect of GRP78 on adaptation/pro-survival of hRPE cells under ER stress. This protein with anti-apoptotic actions in the early UPR and important role in cell fate regulation, can be recruited as a useful candidate for future investigations of RPE degenerative diseases.
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Affiliation(s)
- Shima Ghaderi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Shahin Ahmadian
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Zahra-Soheila Soheili
- Ministry of Science, Research and Technology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Hamid Ahmadieh
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahram Samiei
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Samira Kheitan
- Ministry of Science, Research and Technology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Ehsan R Pirmardan
- Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
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CLINICAL PROGRESS IN INHERITED RETINAL DEGENERATIONS: GENE THERAPY CLINICAL TRIALS AND ADVANCES IN GENETIC SEQUENCING. Retina 2017; 37:417-423. [PMID: 27753762 DOI: 10.1097/iae.0000000000001341] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE Inherited retinal dystrophies are a significant cause of vision loss and are characterized by the loss of photoreceptors and the retinal pigment epithelium (RPE). Mutations in approximately 250 genes cause inherited retinal degenerations with a high degree of genetic heterogeneity. New techniques in next-generation sequencing are allowing the comprehensive analysis of all retinal disease genes thus changing the approach to the molecular diagnosis of inherited retinal dystrophies. This review serves to analyze clinical progress in genetic diagnostic testing and implications for retinal gene therapy. METHODS A literature search of PubMed and OMIM was conducted to relevant articles in inherited retinal dystrophies. RESULTS Next-generation genetic sequencing allows the simultaneous analysis of all the approximately 250 genes that cause inherited retinal dystrophies. Reported diagnostic rates range are high and range from 51% to 57%. These new sequencing tools are highly accurate with sensitivities of 97.9% and specificities of 100%. Retinal gene therapy clinical trials are underway for multiple genes including RPE65, ABCA4, CHM, RS1, MYO7A, CNGA3, CNGB3, ND4, and MERTK for which a molecular diagnosis may be beneficial for patients. CONCLUSION Comprehensive next-generation genetic sequencing of all retinal dystrophy genes is changing the paradigm for how retinal specialists perform genetic testing for inherited retinal degenerations. Not only are high diagnostic yields obtained, but mutations in genes with novel clinical phenotypes are also identified. In the era of retinal gene therapy clinical trials, identifying specific genetic defects will increasingly be of use to identify patients who may enroll in clinical studies and benefit from novel therapies.
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Choudhury SR, Hudry E, Maguire CA, Sena-Esteves M, Breakefield XO, Grandi P. Viral vectors for therapy of neurologic diseases. Neuropharmacology 2017; 120:63-80. [PMID: 26905292 PMCID: PMC5929167 DOI: 10.1016/j.neuropharm.2016.02.013] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 02/07/2016] [Accepted: 02/15/2016] [Indexed: 12/21/2022]
Abstract
Neurological disorders - disorders of the brain, spine and associated nerves - are a leading contributor to global disease burden with a shockingly large associated economic cost. Various treatment approaches - pharmaceutical medication, device-based therapy, physiotherapy, surgical intervention, among others - have been explored to alleviate the resulting extent of human suffering. In recent years, gene therapy using viral vectors - encoding a therapeutic gene or inhibitory RNA into a "gutted" viral capsid and supplying it to the nervous system - has emerged as a clinically viable option for therapy of brain disorders. In this Review, we provide an overview of the current state and advances in the field of viral vector-mediated gene therapy for neurological disorders. Vector tools and delivery methods have evolved considerably over recent years, with the goal of providing greater and safer genetic access to the central nervous system. Better etiological understanding of brain disorders has concurrently led to identification of improved therapeutic targets. We focus on the vector technology, as well as preclinical and clinical progress made thus far for brain cancer and various neurodegenerative and neurometabolic disorders, and point out the challenges and limitations that accompany this new medical modality. Finally, we explore the directions that neurological gene therapy is likely to evolve towards in the future. This article is part of the Special Issue entitled "Beyond small molecules for neurological disorders".
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Affiliation(s)
- Sourav R Choudhury
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Eloise Hudry
- Alzheimer's Disease Research Unit, Harvard Medical School & Massachusetts General Hospital, Charlestown, MA 02129, USA.
| | - Casey A Maguire
- Department of Neurology and Center for Molecular Imaging Research, Department of Radiology, Massachusetts General Hospital and NeuroDiscovery Center, Harvard Medical School, Boston, MA 02114, USA.
| | - Miguel Sena-Esteves
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Xandra O Breakefield
- Department of Neurology and Center for Molecular Imaging Research, Department of Radiology, Massachusetts General Hospital and NeuroDiscovery Center, Harvard Medical School, Boston, MA 02114, USA.
| | - Paola Grandi
- Department of Neurological Surgery, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15219, USA.
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Ryals RC, Andrews MD, Datta S, Coyner AS, Fischer CM, Wen Y, Pennesi ME, McGill TJ. Long-term Characterization of Retinal Degeneration in Royal College of Surgeons Rats Using Spectral-Domain Optical Coherence Tomography. Invest Ophthalmol Vis Sci 2017; 58:1378-1386. [PMID: 28253400 PMCID: PMC5361458 DOI: 10.1167/iovs.16-20363] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Prospective treatments for age-related macular degeneration and inherited retinal degenerations are commonly evaluated in the Royal College of Surgeons (RCS) rat before translation into clinical application. Historically, retinal thickness obtained through postmortem anatomic assessments has been a key outcome measure; however, utility of this measurement is limited because it precludes the ability to perform longitudinal studies. To overcome this limitation, the present study was designed to provide a baseline longitudinal quantification of retinal thickness in the RCS rat by using spectral-domain optical coherence tomography (SD-OCT). Methods Horizontal and vertical linear SD-OCT scans centered on the optic nerve were captured from Long-Evans control rats at P30, P60, P90 and from RCS rats between P17 and P90. Total retina (TR), outer nuclear layer+ (ONL+), inner nuclear layer (INL), and retinal pigment epithelium (RPE) thicknesses were quantified. Histologic sections of RCS retina obtained from P21 to P60 were compared to SD-OCT images. Results In RCS rats, TR and ONL+ thickness decreased significantly as compared to Long-Evans controls. Changes in INL and RPE thickness were not significantly different between control and RCS retinas. From P30 to P90 a subretinal hyperreflective layer (HRL) was observed and quantified in RCS rats. After correlation with histology, the HRL was identified as disorganized outer segments and the location of accumulated debris. Conclusions Retinal layer thickness can be quantified longitudinally throughout the course of retinal degeneration in the RCS rat by using SD-OCT. Thickness measurements obtained with SD-OCT were consistent with previous anatomic thickness assessments. This study provides baseline data for future longitudinal assessment of therapeutic agents in the RCS rat.
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Affiliation(s)
- Renee C Ryals
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Michael D Andrews
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Shreya Datta
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Aaron S Coyner
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Cody M Fischer
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Yuquan Wen
- Baylor University Medical Center, Dallas, Texas, United States
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Trevor J McGill
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States 3Department of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States
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Nakamura PA, Tang S, Shimchuk AA, Ding S, Reh TA. Potential of Small Molecule-Mediated Reprogramming of Rod Photoreceptors to Treat Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2017; 57:6407-6415. [PMID: 27893103 PMCID: PMC5134355 DOI: 10.1167/iovs.16-20177] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Mutations in rod photoreceptor genes can cause retinitis pigmentosa (RP). Rod gene expression is regulated by the nuclear hormone receptor, Nr2e3. Genetic deletion of Nr2e3 reprograms rods into cells that resemble cone photoreceptors, and might therefore prevent their death from some forms of RP. There are no identified ligands for Nr2e3; however, reverse agonists might mimic the genetic rescue effect and may be therapeutically useful for the treatment of RP. Methods We screened for small molecule modulators of Nr2e3 using primary retinal cell cultures and characterized the most potent, which we have named photoregulin1 (PR1), in vitro and in vivo. We also tested the ability of PR1 to slow the progression of photoreceptor degeneration in two common mouse models of autosomal dominant RP, the RhoP23H and the Pde6brd1 mutations. Results In developing retina, PR1 causes a decrease in rod gene expression and an increase in S opsin+ cones. Photoregulin1 continues to inhibit rod gene expression in adult mice. When applied to two mouse models of RP, PR1 slows the degeneration of photoreceptors. Conclusions Chemical compounds identified as modulators of Nr2e3 activity may be useful for the treatment of RP through their effects on expression of disease-causing mutant genes.
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Affiliation(s)
- Paul A Nakamura
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, Washington, United States
| | - Shibing Tang
- University of California-San Francisco, UCSF School of Pharmacy, Department of Pharmaceutical Chemistry, San Francisco California, United States
| | - Andy A Shimchuk
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, Washington, United States
| | - Sheng Ding
- University of California-San Francisco, UCSF School of Pharmacy, Department of Pharmaceutical Chemistry, San Francisco California, United States
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, Washington, United States
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Petit L, Punzo C. Gene therapy approaches for the treatment of retinal disorders. DISCOVERY MEDICINE 2016; 22:221-229. [PMID: 27875674 PMCID: PMC5142441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There is an impelling need to develop effective therapeutic strategies for patients with retinal disorders. Gleaning from the large quantity of information gathered over the past two decades on the mechanisms governing degeneration of the retina, it is now possible to devise innovative therapies based on retinal gene transfer. Different gene-based approaches are under active investigation. They include strategies to correct the specific genetic defect in inherited retinal diseases, strategies to delay the onset of blindness independently of the disease-causing mutations, and strategies to reactivate residual cells at late stages of the diseases. In this review, we discuss the status of application of these technologies, outlining the future therapeutic potential for many forms of retinal blinding diseases.
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Affiliation(s)
- Lolita Petit
- Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Claudio Punzo
- Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Gragg M, Kim TG, Howell S, Park PSH. Wild-type opsin does not aggregate with a misfolded opsin mutant. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1850-9. [PMID: 27117643 DOI: 10.1016/j.bbamem.2016.04.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/06/2016] [Accepted: 04/13/2016] [Indexed: 10/21/2022]
Affiliation(s)
- Megan Gragg
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Tae Gyun Kim
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Scott Howell
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - P S-H Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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Iwabe S, Ying GS, Aguirre GD, Beltran WA. Assessment of visual function and retinal structure following acute light exposure in the light sensitive T4R rhodopsin mutant dog. Exp Eye Res 2016; 146:341-353. [PMID: 27085210 DOI: 10.1016/j.exer.2016.04.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 04/08/2016] [Accepted: 04/11/2016] [Indexed: 01/12/2023]
Abstract
The effect of acute exposure to various intensities of white light on visual behavior and retinal structure was evaluated in the T4R RHO dog, a naturally-occurring model of autosomal dominant retinitis pigmentosa due to a mutation in the Rhodopsin gene. A total of 14 dogs (ages: 4-5.5 months) were used in this study: 3 homozygous mutant RHO(T4R/T4R), 8 heterozygous mutant RHO(T4R/+), and 3 normal wild-type (WT) dogs. Following overnight dark adaptation, the left eyes were acutely exposed to bright white light with a monocular Ganzfeld dome, while the contralateral right eye was shielded. Each of the 3 homozygous (RHO(T4R/T4R)) mutant dogs had a single unilateral light exposure (LE) to a different (low, moderate, and high) dose of white light (corneal irradiance/illuminance: 0.1 mW/cm(2), 170 lux; 0.5 mW/cm(2), 820 lux; or 1 mW/cm(2), 1590 lux) for 1 min. All 8 heterozygous (RHO(T4R/+)) mutant dogs were exposed once to the same moderate dose of light. The 3 WT dogs had their left eyes exposed 1, 2, or 3 times to the same highest dose of light. Visual function prior to LE and at 2 weeks and 33 weeks after exposure was objectively assessed in the RHO(T4R/T4R) and WT dogs by using an obstacle-avoidance course. Transit time through the obstacle course was measured under different scotopic to photopic ambient illuminations. Morphological retinal changes were evaluated by non-invasive in vivo cSLO/sdOCT imaging and histology before and at several time-points (2-36 weeks) after light exposure. The analysis of the transit time through the obstacle course showed that no differences were observed in any of mutant or WT dogs at 2 weeks and 33 weeks post LE. The RHO(T4R/T4R) retina exposed to the lowest dose of white light showed no obvious changes in ONL thickness at 2 weeks, but mild decrease was noted 36 weeks after LE. The RHO(T4R/T4R) retina that received a moderate dose (showed an obvious decrease in ONL thickness along the superior and temporal meridians at 2 weeks post LE with more severe damage at 36 weeks post LE in all four meridians. The RHO(T4R/T4R) retina exposed to the high dose showed at 2 weeks after LE extensive ONL damage in all four meridians. This light intensity did not cause any retinal damage in WT dogs even after repeated (up to 3) LE. Analysis of ONL thickness in heterozygous mutant dogs exposed to the moderate dose of light confirmed the increased sensitivity to light damage of the superior/tapetal retina, and the occurrence of an ongoing cell death process several weeks after the acute LE. In conclusion, a short single exposure to a dose of white light that is not retinotoxic in WT dogs causes in the T4R RHO retina an acute loss of ONL in the central to mid peripheral region that keeps progressing over the course of several weeks. However, this severe retinal damage does not affect visual behavior presumably because of islands of surviving photoreceptors found in the area centralis including the newly discovered canine fovea-like area, and the lack of damage to peripheral photoreceptors.
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Affiliation(s)
- Simone Iwabe
- Section of Ophthalmology, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Gui-Shuang Ying
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Gustavo D Aguirre
- Section of Ophthalmology, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - William A Beltran
- Section of Ophthalmology, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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Trapani I, Banfi S, Simonelli F, Surace EM, Auricchio A. Gene therapy of inherited retinal degenerations: prospects and challenges. Hum Gene Ther 2016; 26:193-200. [PMID: 25762209 DOI: 10.1089/hum.2015.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Because of its favorable anatomical and immunological characteristics, the eye has been at the forefront of translational gene therapy. Dozens of promising proofs of concept have been obtained in animal models of inherited retinal degenerations (IRDs), and some of them have been relayed to the clinic. The results from the first clinical trials for a congenital form of blindness have generated great interest and have demonstrated the safety and efficacy of intraocular administrations of viral vectors in humans. However, this progress has also generated new questions and posed challenges that need to be addressed to further expand the applicability of gene therapy in the eye, including safe delivery of viral vectors to the outer retina, treatment of dominant IRDs as well as of IRDs caused by mutations in large genes, and, finally, selection of the appropriate IRDs and patients to maximize the efficacy of gene transfer. This review summarizes the strategies that are currently being exploited to overcome these challenges and drive the clinical development of retinal gene therapy.
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Affiliation(s)
- Ivana Trapani
- 1 Telethon Institute of Genetics and Medicine (TIGEM) , Pozzuoli, Naples 80078, Italy
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Zulliger R, Conley SM, Naash MI. Non-viral therapeutic approaches to ocular diseases: An overview and future directions. J Control Release 2015; 219:471-487. [PMID: 26439665 PMCID: PMC4699668 DOI: 10.1016/j.jconrel.2015.10.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 10/01/2015] [Accepted: 10/02/2015] [Indexed: 12/31/2022]
Abstract
Currently there are no viable treatment options for patients with debilitating inherited retinal degeneration. The vast variability in disease-inducing mutations and resulting phenotypes has hampered the development of therapeutic interventions. Gene therapy is a logical approach, and recent work has focused on ways to optimize vector design and packaging to promote optimized expression and phenotypic rescue after intraocular delivery. In this review, we discuss ongoing ocular clinical trials, which currently use viral gene delivery, but focus primarily on new advancements in optimizing the efficacy of non-viral gene delivery for ocular diseases. Non-viral delivery systems are highly customizable, allowing functionalization to improve cellular and nuclear uptake, bypassing cellular degradative machinery, and improving gene expression in the nucleus. Non-viral vectors often yield transgene expression levels lower than viral counterparts, however their favorable safety/immune profiles and large DNA capacity (critical for the delivery of large ocular disease genes) make their further development a research priority. Recent work on particle coating and vector engineering presents exciting ways to overcome limitations of transient/low gene expression levels, but also highlights the fact that further refinements are needed before use in the clinic.
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Affiliation(s)
- Rahel Zulliger
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States
| | - Shannon M Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States.
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Retinal gene delivery by adeno-associated virus (AAV) vectors: Strategies and applications. Eur J Pharm Biopharm 2015; 95:343-52. [DOI: 10.1016/j.ejpb.2015.01.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/10/2015] [Accepted: 01/12/2015] [Indexed: 11/20/2022]
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Qi Y, Dai X, Zhang H, He Y, Zhang Y, Han J, Zhu P, Zhang Y, Zheng Q, Li X, Zhao C, Pang J. Trans-Corneal Subretinal Injection in Mice and Its Effect on the Function and Morphology of the Retina. PLoS One 2015; 10:e0136523. [PMID: 26317758 PMCID: PMC4552822 DOI: 10.1371/journal.pone.0136523] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 08/04/2015] [Indexed: 11/18/2022] Open
Abstract
Purpose To introduce a practical method of subretinal injection in mice and evaluate injection-induced retinal detachment (RD) and damage using a dynamic imaging system, electrophysiology, and histology. Methods After full dilation of a 2-month-old C57BL/6J mouse pupil, the cornea near the limbus was punctured with a 30 ½-gague disposable beveled needle. A 33 ½-gauge blunt needle was inserted through the corneal perforation into the anterior chamber, avoiding the lens before going deeper into the vitreous cavity, and penetrating the inner retina to reach the subretinal space. The mice were divided into four groups: in group 1, about 80–100% of the retina was filled with subretinally injected solution; in group 2, approximately 50–70% of the retina was filled with injected solution; in group 3, the procedures were stopped before solution injection; and non-injected eyes were used as the negative control in group 4. An optical coherence tomography (OCT) imaging system was used to monitor retinal reattachment during the first three days following the injections. Histological and functional changes were examined by light microscopy and electroretinography (ERG) at five weeks post-injection. Results After a short-term training, a 70% success rate with 50% or more coverage (i.e., retinal blebs occupied 50% or more retinal area and filled with the injected solution) with minimal injection-related damages can be achieved. Bleb formation was associated with retinal detachment (RD) between the neuroretina and the retinal pigment epithelium (RPE) layer. Partial RD could be observed at post-injection day 1, and by day 2 most of the retina had reattached. At 5 weeks post-injection, compared to uninjected control group 4, the b-wave amplitudes of ERG decreased 22% in group 1, 16% in group 2, and 7% in group 3; the b-wave amplitudes were statistically different between the uninjected group and the groups with either 50–70% or 80–100% coverage. The subretinal injection-induced RD reattached and became stable at five weeks post-injection, although some photoreceptor damage could still be observed in and around the injection sites, especially in 80–100% coverage group. Conclusions Trans-corneal subretinal injection is effective and practical, although subretinal injection-related damages can cause some morphological and functional loss.
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Affiliation(s)
- Yan Qi
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
| | - Xufeng Dai
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
| | - Hua Zhang
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
| | - Ying He
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
| | - Yangyang Zhang
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
| | - Juanjuan Han
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
- Fenyang College of Shanxi Medical University, Fenyang, Shanxi, P. R. China
| | - Ping Zhu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Yuxin Zhang
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- Department of Ophthalmology, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, P. R. China
| | - Qinxiang Zheng
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
| | - Xia Li
- Department of Ophthalmology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, P. R. China
| | - Chen Zhao
- Department of Ophthalmology, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, P. R. China
| | - Jijing Pang
- School of Ophthalmology & Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- Department of Ophthalmology, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, P. R. China
- * E-mail:
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Chen Y, Tang H, Seibel W, Papoian R, Li X, Lambert NA, Palczewski K. A High-Throughput Drug Screening Strategy for Detecting Rhodopsin P23H Mutant Rescue and Degradation. Invest Ophthalmol Vis Sci 2015; 56:2553-67. [PMID: 25783607 DOI: 10.1167/iovs.14-16298] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Inherent instability of the P23H mutant opsin accounts for approximately 10% of autosomal dominant retinitis pigmentosa cases. Our purpose was to develop an overall set of reliable screening strategies to assess if either stabilization or enhanced degradation of mutant rhodopsin could rescue rod photoreceptors expressing this mutant protein. These strategies promise to reveal active compounds and clarify molecular mechanisms of biologically important processes, such as inhibition of target degradation or enhanced target folding. METHODS Cell-based bioluminescence reporter assays were developed and validated for high-throughput screening (HTS) of compounds that promote either stabilization or degradation of P23H mutant opsin. Such assays were further complemented by immunoblotting and image-based analyses. RESULTS Two stabilization assays of P23H mutant opsin were developed and validated, one based on β-galactosidase complementarity and a second assay involving bioluminescence resonance energy transfer (BRET) technology. Moreover, two additional assays evaluating mutant protein degradation also were employed, one based on the disappearance of luminescence and another employing the ALPHA immunoassay. Imaging of cells revealed the cellular localization of mutant rhodopsin, whereas immunoblots identified changes in the aggregation and glycosylation of P23H mutant opsin. CONCLUSIONS Our findings indicate that these initial HTS and following assays can identify active therapeutic compounds, even for difficult targets such as mutant rhodopsin. The assays are readily scalable and their function has been proven with model compounds. High-throughput screening, supported by automated imaging and classic immunoassays, can further characterize multiple steps and pathways in the biosynthesis and degradation of this essential visual system protein.
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Affiliation(s)
- Yuanyuan Chen
- Department of Pharmacology Case Western Reserve University, Cleveland, Ohio, United States
| | - Hong Tang
- Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - William Seibel
- Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Ruben Papoian
- Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Xiaoyu Li
- Department of Pharmacology Case Western Reserve University, Cleveland, Ohio, United States
| | - Nevin A Lambert
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, Georgia, United States
| | - Krzysztof Palczewski
- Department of Pharmacology Case Western Reserve University, Cleveland, Ohio, United States
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Thompson DA, Ali RR, Banin E, Branham KE, Flannery JG, Gamm DM, Hauswirth WW, Heckenlively JR, Iannaccone A, Jayasundera KT, Khan NW, Molday RS, Pennesi ME, Reh TA, Weleber RG, Zacks DN. Advancing therapeutic strategies for inherited retinal degeneration: recommendations from the Monaciano Symposium. Invest Ophthalmol Vis Sci 2015; 56:918-31. [PMID: 25667399 DOI: 10.1167/iovs.14-16049] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although rare in the general population, retinal dystrophies occupy a central position in current efforts to develop innovative therapies for blinding diseases. This status derives, in part, from the unique biology, accessibility, and function of the retina, as well as from the synergy between molecular discoveries and transformative advances in functional assessment and retinal imaging. The combination of these factors has fueled remarkable progress in the field, while at the same time creating complex challenges for organizing collective efforts aimed at advancing translational research. The present position paper outlines recent progress in gene therapy and cell therapy for this group of disorders, and presents a set of recommendations for addressing the challenges remaining for the coming decade. It is hoped that the formulation of these recommendations will stimulate discussions among researchers, funding agencies, industry, and policy makers that will accelerate the development of safe and effective treatments for retinal dystrophies and related diseases.
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Affiliation(s)
- Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Robin R Ali
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States Division of Molecular Therapy, University College London Institute of Ophthalmology, London, England, United Kingdom
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Kari E Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - John G Flannery
- Helen Wills Neuroscience Institute, University of California-Berkeley, Berkeley, California, United States
| | - David M Gamm
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Alessandro Iannaccone
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - K Thiran Jayasundera
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Naheed W Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Robert S Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mark E Pennesi
- Casey Eye Institute and the Department of Ophthalmology, Oregon Health and Science University, Portland, Oregon, United States
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, Washington, United States
| | - Richard G Weleber
- Casey Eye Institute and the Department of Ophthalmology, Oregon Health and Science University, Portland, Oregon, United States Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, United States
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
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Berger A, Lorain S, Joséphine C, Desrosiers M, Peccate C, Voit T, Garcia L, Sahel JA, Bemelmans AP. Repair of rhodopsin mRNA by spliceosome-mediated RNA trans-splicing: a new approach for autosomal dominant retinitis pigmentosa. Mol Ther 2015; 23:918-930. [PMID: 25619725 PMCID: PMC4427870 DOI: 10.1038/mt.2015.11] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/12/2015] [Indexed: 12/26/2022] Open
Abstract
The promising clinical results obtained for ocular gene therapy in recent years have paved the way for gene supplementation to treat recessively inherited forms of retinal degeneration. The situation is more complex for dominant mutations, as the toxic mutant gene product must be removed. We used spliceosome-mediated RNA trans-splicing as a strategy for repairing the transcript of the rhodopsin gene, the gene most frequently mutated in autosomal dominant retinitis pigmentosa. We tested 17 different molecules targeting the pre-mRNA intron 1, by transient transfection of HEK-293T cells, with subsequent trans-splicing quantification at the transcript level. We found that the targeting of some parts of the intron promoted trans-splicing more efficiently than the targeting of other areas, and that trans-splicing rate could be increased by modifying the replacement sequence. We then developed cell lines stably expressing the rhodopsin gene, for the assessment of phenotypic criteria relevant to the pathogenesis of retinitis pigmentosa. Using this model, we showed that trans-splicing restored the correct localization of the protein to the plasma membrane. Finally, we tested our best candidate by AAV gene transfer in a mouse model of retinitis pigmentosa that expresses a mutant allele of the human rhodopsin gene, and demonstrated the feasibility of trans-splicing in vivo. This work paves the way for trans-splicing gene therapy to treat retinitis pigmentosa due to rhodopsin gene mutation and, more generally, for the treatment of genetic diseases with dominant transmission.
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Affiliation(s)
- Adeline Berger
- Centre de recherche Institut de la Vision, Sorbonne Universités, Université Pierre et Marie Curie UM80, INSERM U968, and CNRS UMR 7210, Paris, France
| | - Stéphanie Lorain
- Centre de recherche en Myologie, Sorbonne Universités, Université Pierre et Marie Curie, UM76, INSERM U974 and CNRS FRE 3617, Paris, France
| | - Charlène Joséphine
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département des Sciences du Vivant (DSV), Institut d'Imagerie Biomédicale (I2BM), MIRCen, Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | - Melissa Desrosiers
- Centre de recherche Institut de la Vision, Sorbonne Universités, Université Pierre et Marie Curie UM80, INSERM U968, and CNRS UMR 7210, Paris, France
| | - Cécile Peccate
- Centre de recherche en Myologie, Sorbonne Universités, Université Pierre et Marie Curie, UM76, INSERM U974 and CNRS FRE 3617, Paris, France
| | - Thomas Voit
- Centre de recherche en Myologie, Sorbonne Universités, Université Pierre et Marie Curie, UM76, INSERM U974 and CNRS FRE 3617, Paris, France
| | - Luis Garcia
- UFR des sciences de la santé Simone Veil, Université Versailles Saint-Quentin, Montigny-le-Bretonneux, France
| | - José-Alain Sahel
- Centre de recherche Institut de la Vision, Sorbonne Universités, Université Pierre et Marie Curie UM80, INSERM U968, and CNRS UMR 7210, Paris, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, Paris, France; Fondation Ophtalmologique Adolphe de Rothschild, Paris, France; Institute of Ophthalmology, University College of London, London, UK
| | - Alexis-Pierre Bemelmans
- Centre de recherche Institut de la Vision, Sorbonne Universités, Université Pierre et Marie Curie UM80, INSERM U968, and CNRS UMR 7210, Paris, France; Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département des Sciences du Vivant (DSV), Institut d'Imagerie Biomédicale (I2BM), MIRCen, Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France.
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Rossmiller BP, Ryals RC, Lewin AS. Gene therapy to rescue retinal degeneration caused by mutations in rhodopsin. Methods Mol Biol 2015; 1271:391-410. [PMID: 25697537 PMCID: PMC4696870 DOI: 10.1007/978-1-4939-2330-4_25] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Retinal gene therapy has proven safe and at least partially successful in clinical trials and in numerous animal models. Gene therapy requires characterization of the progression of the disease and understanding of its genetic cause. Testing gene therapies usually requires an animal model that recapitulates the key features of the human disease, though photoreceptors and cells of the retinal pigment epithelium produced from patient-derived stem cells may provide an alternative test system for retinal gene therapy. Gene therapy also requires a delivery system that introduces the therapeutic gene to the correct cell type and does not cause unintended damage to the tissue. Current systems being tested in the eye are nanoparticles, pseudotyped lentiviruses, and adeno-associated virus (AAV) of various serotypes. Here, we describe the techniques of AAV vector design as well as the in vivo and ex vivo tests necessary for assessing the efficacy of retinal gene therapy to treat retinal degeneration caused by mutations in the rhodopsin gene.
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Affiliation(s)
- Brian P Rossmiller
- Department of Opthalmology, University of Florida, Box 100284, Gainesville, FL, 32610-0284, USA
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Rex TS. Gene therapy to treat inherited and complex retinal degenerative diseases. Mol Ther Methods Clin Dev 2015; 2:15027. [PMID: 26251841 PMCID: PMC4525775 DOI: 10.1038/mtm.2015.27] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 03/11/2015] [Indexed: 01/22/2023]
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Trapani I, Puppo A, Auricchio A. Vector platforms for gene therapy of inherited retinopathies. Prog Retin Eye Res 2014; 43:108-28. [PMID: 25124745 PMCID: PMC4241499 DOI: 10.1016/j.preteyeres.2014.08.001] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/26/2014] [Accepted: 08/02/2014] [Indexed: 12/20/2022]
Abstract
Inherited retinopathies (IR) are common untreatable blinding conditions. Most of them are inherited as monogenic disorders, due to mutations in genes expressed in retinal photoreceptors (PR) and in retinal pigment epithelium (RPE). The retina's compatibility with gene transfer has made transduction of different retinal cell layers in small and large animal models via viral and non-viral vectors possible. The ongoing identification of novel viruses as well as modifications of existing ones based either on rational design or directed evolution have generated vector variants with improved transduction properties. Dozens of promising proofs of concept have been obtained in IR animal models with both viral and non-viral vectors, and some of them have been relayed to clinical trials. To date, recombinant vectors based on the adeno-associated virus (AAV) represent the most promising tool for retinal gene therapy, given their ability to efficiently deliver therapeutic genes to both PR and RPE and their excellent safety and efficacy profiles in humans. However, AAVs' limited cargo capacity has prevented application of the viral vector to treatments requiring transfer of genes with a coding sequence larger than 5 kb. Vectors with larger capacity, i.e. nanoparticles, adenoviral and lentiviral vectors are being exploited for gene transfer to the retina in animal models and, more recently, in humans. This review focuses on the available platforms for retinal gene therapy to fight inherited blindness, highlights their main strengths and examines the efforts to overcome some of their limitations.
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Affiliation(s)
- Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | - Agostina Puppo
- 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 University, Naples, Italy.
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Conley SM, Naash MI. Gene therapy for PRPH2-associated ocular disease: challenges and prospects. Cold Spring Harb Perspect Med 2014; 4:a017376. [PMID: 25167981 DOI: 10.1101/cshperspect.a017376] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The peripherin-2 (PRPH2) gene encodes a photoreceptor-specific tetraspanin protein called peripherin-2/retinal degeneration slow (RDS), which is critical for the formation and maintenance of rod and cone outer segments. Over 90 different disease-causing mutations in PRPH2 have been identified, which cause a variety of forms of retinitis pigmentosa and macular degeneration. Given the disease burden associated with PRPH2 mutations, the gene has long been a focus for preclinical gene therapy studies. Adeno-associated viruses and compacted DNA nanoparticles carrying PRPH2 have been successfully used to mediate improvement in the rds(-/-) and rds(+/-) mouse models. However, complexities in the pathogenic mechanism for PRPH2-associated macular disease coupled with the need for a precise dose of peripherin-2 to combat a severe haploinsufficiency phenotype have delayed the development of clinically viable genetic treatments. Here we discuss the progress and prospects for PRPH2-associated gene therapy.
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Affiliation(s)
- Shannon M Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Muna I Naash
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
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Recent advances of stem cell therapy for retinitis pigmentosa. Int J Mol Sci 2014; 15:14456-74. [PMID: 25141102 PMCID: PMC4159862 DOI: 10.3390/ijms150814456] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/24/2014] [Accepted: 08/11/2014] [Indexed: 12/22/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal disorders characterized by progressive loss of photoreceptors and eventually leads to retina degeneration and atrophy. Until now, the exact pathogenesis and etiology of this disease has not been clear, and many approaches for RP therapies have been carried out in animals and in clinical trials. In recent years, stem cell transplantation-based attempts made some progress, especially the transplantation of bone marrow-derived mesenchymal stem cells (BMSCs). This review will provide an overview of stem cell-based treatment of RP and its main problems, to provide evidence for the safety and feasibility for further clinical treatment.
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Guzman-Aranguez A, Loma P, Pintor J. Small-interfering RNAs (siRNAs) as a promising tool for ocular therapy. Br J Pharmacol 2014; 170:730-47. [PMID: 23937539 DOI: 10.1111/bph.12330] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/23/2013] [Accepted: 08/04/2013] [Indexed: 12/26/2022] Open
Abstract
RNA interference (RNAi) can be used to inhibit the expression of specific genes in vitro and in vivo, thereby providing an extremely useful tool for investigating gene function. Progress in the understanding of RNAi-based mechanisms has opened up new perspectives in therapeutics for the treatment of several diseases including ocular disorders. The eye is currently considered a good target for RNAi therapy mainly because it is a confined compartment and, therefore, enables local delivery of small-interfering RNAs (siRNAs) by topical instillation or direct injection. However, delivery strategies that protect the siRNAs from degradation and are suitable for long-term treatment would be help to improve the efficacy of RNAi-based therapies for ocular pathologies. siRNAs targeting critical molecules involved in the pathogenesis of glaucoma, retinitis pigmentosa and neovascular eye diseases (age-related macular degeneration, diabetic retinopathy and corneal neovascularization) have been tested in experimental animal models, and clinical trials have been conducted with some of them. This review provides an update on the progress of RNAi in ocular therapeutics, discussing the advantages and drawbacks of RNAi-based therapeutics compared to previous treatments.
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Affiliation(s)
- A Guzman-Aranguez
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
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