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Teh DBL, Bansal A, Chai C, Toh TB, Tucker RAJ, Gammad GGL, Yeo Y, Lei Z, Zheng X, Yang F, Ho JS, Bolem N, Wu BC, Gnanasammandhan MK, Hooi L, Dawe GS, Libedinsky C, Ong WY, Halliwell B, Chow EKH, Lim KL, Zhang Y, Kennedy BK. A Flexi-PEGDA Upconversion Implant for Wireless Brain Photodynamic Therapy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2001459. [PMID: 32484308 DOI: 10.1002/adma.202001459] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/18/2020] [Accepted: 04/20/2020] [Indexed: 05/12/2023]
Abstract
Near-infrared (NIR) activatable upconversion nanoparticles (UCNPs) enable wireless-based phototherapies by converting deep-tissue-penetrating NIR to visible light. UCNPs are therefore ideal as wireless transducers for photodynamic therapy (PDT) of deep-sited tumors. However, the retention of unsequestered UCNPs in tissue with minimal options for removal limits their clinical translation. To address this shortcoming, biocompatible UCNPs implants are developed to deliver upconversion photonic properties in a flexible, optical guide design. To enhance its translatability, the UCNPs implant is constructed with an FDA-approved poly(ethylene glycol) diacrylate (PEGDA) core clad with fluorinated ethylene propylene (FEP). The emission spectrum of the UCNPs implant can be tuned to overlap with the absorption spectra of the clinically relevant photosensitizer, 5-aminolevulinic acid (5-ALA). The UCNPs implant can wirelessly transmit upconverted visible light till 8 cm in length and in a bendable manner even when implanted underneath the skin or scalp. With this system, it is demonstrated that NIR-based chronic PDT is achievable in an untethered and noninvasive manner in a mouse xenograft glioblastoma multiforme (GBM) model. It is postulated that such encapsulated UCNPs implants represent a translational shift for wireless deep-tissue phototherapy by enabling sequestration of UCNPs without compromising wireless deep-tissue light delivery.
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Affiliation(s)
- Daniel Boon Loong Teh
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
| | - Akshaya Bansal
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Chou Chai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Tan Boon Toh
- The N.1 Institute for Health, National University of Singapore, Singapore, 117599, Singapore
| | - Robert Alan Jappy Tucker
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
| | - Gil Gerald Lasam Gammad
- The N.1 Institute for Health, National University of Singapore, Singapore, 117599, Singapore
| | - Yanzhuang Yeo
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Zhendong Lei
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117583, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117456, Singapore
| | - Xiang Zheng
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117583, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117456, Singapore
| | - Fengyuan Yang
- Department of Electrical & Computer Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - John S Ho
- The N.1 Institute for Health, National University of Singapore, Singapore, 117599, Singapore
- Department of Electrical & Computer Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Nagarjun Bolem
- Division of Neurosurgery, National University Hospital, Singapore, 119228, Singapore
| | - Bing Cheng Wu
- Department of Pathology, National University Hospital, Singapore, 119228, Singapore
| | - Muthu Kumar Gnanasammandhan
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Lissa Hooi
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
| | - Gavin Stewart Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Camilo Libedinsky
- The N.1 Institute for Health, National University of Singapore, Singapore, 117599, Singapore
- Department of Psychology, Faculty of Arts and Social Sciences, National University of Singapore, Singapore, 117570, Singapore
| | - Wei-Yi Ong
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117594, Singapore
| | - Barry Halliwell
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
| | - Edward Kai-Hua Chow
- The N.1 Institute for Health, National University of Singapore, Singapore, 117599, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, 117599, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Kah-Leong Lim
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Yong Zhang
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Brian K Kennedy
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore
- Center for Healthy Ageing, National University Health System, Singapore, 119228, Singapore
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Affiliation(s)
- Katrin Franke
- Institute for Ophthalmic Research, Bernstein Center for Computational Neuroscience, Center for Integrative Neuroscience, Tübingen University, 72076 Tübingen, Germany.
| | - Anna Vlasits
- Institute for Ophthalmic Research, Bernstein Center for Computational Neuroscience, Center for Integrative Neuroscience, Tübingen University, 72076 Tübingen, Germany
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Comparison of AAV-Mediated Optogenetic Vision Restoration between Retinal Ganglion Cell Expression and ON Bipolar Cell Targeting. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 18:15-23. [PMID: 32548211 PMCID: PMC7287188 DOI: 10.1016/j.omtm.2020.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 01/06/2023]
Abstract
The loss of photoreceptors in individuals with retinal degenerative diseases leads to partial or complete blindness. Optogenetic therapy is a promising approach for restoring vision to the blind. Multiple strategies have been employed by targeting genetically encoded light sensors, particularly channelrhodopsins, to surviving retinal neurons in animal models. In particular, the strategy of targeting retinal bipolar cells has commonly been expected to result in better vision than ubiquitous expression in retinal ganglion cells. However, a direct comparison of the channelrhodopsin-restored vision between these two strategies has not been performed. Here, we compared the restored visual functions achieved by adeno-associated virus (AAV)-mediated expression of a channelrhodopsin in ON-type bipolar cells and retinal ganglion cells driven by an improved mGluR6 promoter and a CAG promoter, respectively, in a blind mouse model by performing electrophysiological recordings and behavioral assessments. Unexpectedly, the efficacy of the restored vision based on light sensitivity and visual acuity was much higher following ubiquitous retinal ganglion cell expression than that of the strategy targeting ON-type bipolar cells. Our study suggests that, at least based on currently available gene delivery techniques, the expression of genetically encoded light sensors in retinal ganglion cells is likely a practical and advantageous strategy for optogenetic vision restoration.
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Talib M, Boon CJF. Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations. Asia Pac J Ophthalmol (Phila) 2020; 9:159-179. [PMID: 32511120 PMCID: PMC7299224 DOI: 10.1097/apo.0000000000000290] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam. Amsterdam, The Netherlands
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55
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Gene therapy beyond luxturna: a new horizon of the treatment for inherited retinal disease. Curr Opin Ophthalmol 2020; 31:147-154. [DOI: 10.1097/icu.0000000000000660] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Trapani I, Auricchio A. Has retinal gene therapy come of age? From bench to bedside and back to bench. Hum Mol Genet 2020; 28:R108-R118. [PMID: 31238338 PMCID: PMC6797000 DOI: 10.1093/hmg/ddz130] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 04/24/2019] [Accepted: 06/07/2019] [Indexed: 02/06/2023] Open
Abstract
Retinal gene therapy has advanced considerably in the past three decades. Initial efforts have been devoted to comprehensively explore and optimize the transduction abilities of gene delivery vectors, define the appropriate intraocular administration routes and obtain evidence of efficacy in animal models of inherited retinal diseases (IRDs). Successful translation in clinical trials of the initial promising proof-of-concept studies led to the important milestone of the first approved product for retinal gene therapy in both US and Europe. The unprecedented clinical development observed during the last decade in the field is however highlighting new challenges that will need to be overcome to bring gene therapy to fruition to a larger patient population within and beyond the realm of IRDs.
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Affiliation(s)
- Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Advanced Biomedicine, Federico II University, Naples, Italy
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Puertas-Neyra K, Usategui-Martín R, Coco RM, Fernandez-Bueno I. Intravitreal stem cell paracrine properties as a potential neuroprotective therapy for retinal photoreceptor neurodegenerative diseases. Neural Regen Res 2020; 15:1631-1638. [PMID: 32209762 PMCID: PMC7437593 DOI: 10.4103/1673-5374.276324] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Retinal degenerations are the leading causes of irreversible visual loss worldwide. Many pathologies included under this umbrella involve progressive degeneration and ultimate loss of the photoreceptor cells, with age-related macular degeneration and inherited and ischemic retinal diseases the most relevant. These diseases greatly impact patients’ daily lives, with accompanying marked social and economic consequences. However, the currently available treatments only delay the onset or slow progression of visual impairment, and there are no cures for these photoreceptor diseases. Therefore, new therapeutic strategies are being investigated, such as gene therapy, optogenetics, cell replacement, or cell-based neuroprotection. Specifically, stem cells can secrete neurotrophic, immunomodulatory, and anti-angiogenic factors that potentially protect and preserve retinal cells from neurodegeneration. Further, neuroprotection can be used in different types of retinal degenerative diseases and at different disease stages, unlike other potential therapies. This review summarizes stem cell-based paracrine neuroprotective strategies for photoreceptor degeneration, which are under study in clinical trials, and the latest preclinical studies. Effective retinal neuroprotection could be the next frontier in photoreceptor diseases, and the development of novel neuroprotective strategies will address the unmet therapeutic needs.
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Affiliation(s)
- Kevin Puertas-Neyra
- Instituto Universitario de Oftalmobiología Aplicada, Universidad de Valladolid, Valladolid, Spain
| | - Ricardo Usategui-Martín
- Instituto Universitario de Oftalmobiología Aplicada, Universidad de Valladolid, Valladolid, Spain
| | - Rosa M Coco
- Instituto Universitario de Oftalmobiología Aplicada, Universidad de Valladolid; Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León; Red Temática de Investigación Cooperativa en Salud, Oftared, Instituto de Salud Carlos III, Valladolid, Spain
| | - Ivan Fernandez-Bueno
- Instituto Universitario de Oftalmobiología Aplicada, Universidad de Valladolid; Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León; Red Temática de Investigación Cooperativa en Salud, Oftared, Instituto de Salud Carlos III, Valladolid, Spain
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59
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Stingl KT, Kuehlewein L, Weisschuh N, Biskup S, Cremers FPM, Khan MI, Kelbsch C, Peters T, Ueffing M, Wilhelm B, Zrenner E, Stingl K. Chromatic Full-Field Stimulus Threshold and Pupillography as Functional Markers for Late-Stage, Early-Onset Retinitis Pigmentosa Caused by CRB1 Mutations. Transl Vis Sci Technol 2019; 8:45. [PMID: 31879567 PMCID: PMC6927735 DOI: 10.1167/tvst.8.6.45] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/30/2019] [Indexed: 01/08/2023] Open
Abstract
Purpose Mutations in the CRB1 gene cause early-onset retinal degeneration (EORD). Clinical disease progression markers, such as visual fields or electrophysiology, are not reliably measurable in most patients to follow the retinal function in patients with CRB1-mutations. Methods Ten patients (five females, five males; age 22–56 years) with EORD caused by CRB1 mutations were examined in a cross-sectional manner using best corrected visual acuity (BCVA), perimetry, full-field and multifocal electroretinography, full-field stimulus threshold (FST), and pupillography to red and blue light. Disease duration was defined as the difference between the age at the first symptoms to the age at examination in years. Results BCVA was quantifiable in six patients and ranged from light perception to 20/50. The visual field was measurable only in three patients who had the shortest disease duration. Full-field and multifocal electroretinography were not measurable in any patient. FST to blue and red light were measurable in all patients except the one with the longest disease duration; the thresholds ranged from −16.7 to 1.5 dB for red light and from −40.2 to 2.5 dB for blue light (0 dB = 0.01 cd.s/m2) and showed correlations with disease duration (r = 0.87 for blue, r = 0.65 for red, r = 0.8 for blue–red difference). The maximal relative pupil constriction amplitude (MRA) showed low or no correlations with disease duration (r = −0.55 for blue, r = −0.3 for red light); the blue–red difference in the post-illumination pupil responses (PIPR) showed no correlation with disease duration (r = −0.05). Compared to healthy eyes, the MRA to red and blue light was significantly decreased (P < 0.001) and the blue–red PIPR difference was significantly increased (P = 0.003). Conclusions FST features a valid clinical marker in late-stage early-onset retinitis pigmentosa caused by CRB1 mutations correlating with disease duration. This indicates the potential as a progression marker of disease. The pupil responses to full-field chromatic stimuli show significant differences from the normal population: the remaining responses, although reduced, indicate a partially preserved inner retinal function despite severe photoreceptor dysfunction. Translational Relevance The functional measurements presented in this study present a valid clinical progression marker in late-stage early onset retinitis pigmentosa caused by biallelic CRB1 mutations. Additionally, they can be used as outcome measures for safety and efficacy in clinical therapy trials.
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Affiliation(s)
| | - Laura Kuehlewein
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Nicole Weisschuh
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | | | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center and Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - M Imran Khan
- Department of Human Genetics, Radboud University Medical Center and Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Carina Kelbsch
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Tobias Peters
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Barbara Wilhelm
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Eberhart Zrenner
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany.,Werner Reichardt Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - Katarina Stingl
- Center for Ophthalmology, University of Tübingen, Tübingen, Germany
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Montazeri L, El Zarif N, Trenholm S, Sawan M. Optogenetic Stimulation for Restoring Vision to Patients Suffering From Retinal Degenerative Diseases: Current Strategies and Future Directions. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2019; 13:1792-1807. [PMID: 31689206 DOI: 10.1109/tbcas.2019.2951298] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Optogenetic strategies for vision restoration involve photosensitizing surviving retinal neurons following retinal degeneration, using emerging optogenetic techniques. This approach opens the door to a minimally-invasive retinal vision restoration approach. Moreover, light stimulation has the potential to offer better spatial and temporal resolution than conventional retinal electrical prosthetics. Although proof-of-concept studies in animal models have demonstrated the possibility of restoring vision using optogenetic techniques, and initial clinical trials are underway, there are still hurdles to pass before such an approach restores naturalistic vision in humans. One limitation is the development of light stimulation devices to activate optogenetic channels in the retina. Here we review recent progress in the design and implementation of optogenetic stimulation devices and outline the corresponding technological challenges. Finally, while most work to date has focused on providing therapy to patients suffering from retinitis pigmentosa, we provide additional insights into strategies for applying optogenetic vision restoration to patients suffering from age-related macular degeneration.
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Sumaroka A, Cideciyan AV, Charng J, Wu V, Powers CA, Iyer BS, Lisi B, Swider M, Jacobson SG. Autosomal Dominant Retinitis Pigmentosa Due to Class B Rhodopsin Mutations: An Objective Outcome for Future Treatment Trials. Int J Mol Sci 2019; 20:ijms20215344. [PMID: 31717845 PMCID: PMC6861901 DOI: 10.3390/ijms20215344] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/09/2019] [Accepted: 10/16/2019] [Indexed: 12/27/2022] Open
Abstract
Gene therapy for adRP due to RHO mutations was recently shown to prevent photoreceptor death in a canine model of Class B disease. Among translational steps to be taken, one is to determine a method to detect efficacy in a human clinical trial. The relatively slow progression of adRP becomes a difficulty for clinical trials requiring an answer to whether there is slowed progression of degeneration in response to therapy. We performed a single-center, retrospective observational study of cross-sectional and longitudinal data. The study was prompted by our identification of a pericentral disease distribution in Class B RHO-adRP. Ultrawide optical coherence tomography (OCT) scans were used. Inferior retinal pericentral defects was an early disease feature. Degeneration further inferior in the retina merged with the pericentral defect, which extended into superior retina. In about 70% of patients, there was an asymmetric island of structure with significantly greater superior than inferior ellipsoid zone (EZ) extent. Serial measures of photoreceptor structure by OCT indicated constriction in superior retinal extent within a two-year interval. We conclude that these results should allow early-phase trials of therapy in RHO-adRP to move forward by inclusion of patients with an asymmetric extent of photoreceptor structure and by monitoring therapeutic effects over two years in the superior retina, a reasonable target for subretinal injection.
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Cehajic Kapetanovic J, Barnard AR, MacLaren RE. Molecular Therapies for Choroideremia. Genes (Basel) 2019; 10:genes10100738. [PMID: 31548516 PMCID: PMC6826983 DOI: 10.3390/genes10100738] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/14/2019] [Accepted: 09/20/2019] [Indexed: 01/03/2023] Open
Abstract
Advances in molecular research have culminated in the development of novel gene-based therapies for inherited retinal diseases. We have recently witnessed several groundbreaking clinical studies that ultimately led to approval of Luxturna, the first gene therapy for an inherited retinal disease. In parallel, international research community has been engaged in conducting gene therapy trials for another more common inherited retinal disease known as choroideremia and with phase III clinical trials now underway, approval of this therapy is poised to follow suit. This chapter discusses new insights into clinical phenotyping and molecular genetic testing in choroideremia with review of molecular mechanisms implicated in its pathogenesis. We provide an update on current gene therapy trials and discuss potential inclusion of female carries in future clinical studies. Alternative molecular therapies are discussed including suitability of CRISPR gene editing, small molecule nonsense suppression therapy and vision restoration strategies in late stage choroideremia.
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Affiliation(s)
- Jasmina Cehajic Kapetanovic
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK; (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Correspondence:
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK; (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK; (A.R.B.); (R.E.M.)
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
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Lamprecht R. Regulation of signaling proteins in the brain by light. Prog Neurobiol 2019; 180:101638. [DOI: 10.1016/j.pneurobio.2019.101638] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/29/2019] [Accepted: 06/06/2019] [Indexed: 12/20/2022]
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Vázquez-Domínguez I, Garanto A, Collin RWJ. Molecular Therapies for Inherited Retinal Diseases-Current Standing, Opportunities and Challenges. Genes (Basel) 2019; 10:genes10090654. [PMID: 31466352 PMCID: PMC6770110 DOI: 10.3390/genes10090654] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 12/15/2022] Open
Abstract
Inherited retinal diseases (IRDs) are both genetically and clinically highly heterogeneous and have long been considered incurable. Following the successful development of a gene augmentation therapy for biallelic RPE65-associated IRD, this view has changed. As a result, many different therapeutic approaches are currently being developed, in particular a large variety of molecular therapies. These are depending on the severity of the retinal degeneration, knowledge of the pathophysiological mechanism underlying each subtype of IRD, and the therapeutic target molecule. DNA therapies include approaches such as gene augmentation therapy, genome editing and optogenetics. For some genetic subtypes of IRD, RNA therapies and compound therapies have also shown considerable therapeutic potential. In this review, we summarize the current state-of-the-art of various therapeutic approaches, including the pros and cons of each strategy, and outline the future challenges that lie ahead in the combat against IRDs.
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Affiliation(s)
- Irene Vázquez-Domínguez
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands
| | - Alejandro Garanto
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
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Photoreceptor cell replacement in macular degeneration and retinitis pigmentosa: A pluripotent stem cell-based approach. Prog Retin Eye Res 2019; 71:1-25. [DOI: 10.1016/j.preteyeres.2019.03.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/01/2019] [Accepted: 03/12/2019] [Indexed: 02/07/2023]
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Ueno S, Kominami T, Okado S, Inooka D, Kondo M, Terasaki H. Course of loss of photoreceptor function and progressive Müller cell gliosis in rhodopsin P347L transgenic rabbits. Exp Eye Res 2019; 184:192-200. [PMID: 31029790 DOI: 10.1016/j.exer.2019.04.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 01/31/2023]
Abstract
Long living animal models of retinitis pigmentosa (RP) can provide important information on the retinal changes that occur at the late stages of photoreceptor degeneration. The rhodopsin Pro347Leu transgenic rabbit (P347L Tg) is a model of RP, and it has been used to analyze the functional and morphological changes in the retina following the degeneration of the photoreceptors. They have also been used to test newly-developed therapies to treat eyes with photoreceptor degeneration. However, assessments of the retinal changes in P347L Tg rabbits older than 1-year have not been reported even though the data are important for research on developing new therapies to restore vision at the end stages of RP. The purpose of this study was to determine the time course of the loss of photoreceptor function and the changes in the morphology of the retina of P347L Tg rabbits. The experiments were performed on 26 older P347L Tg rabbits. The results showed that the amplitudes of the ERGs of the P347L Tg rabbits gradually decreased and reached <10 μV between 30- and 54-months-of-age. Histological analysis at these later stages showed a loss of the photoreceptor layer, and OCT analysis showed absence of the layering of the retina. However, the thickness between the inner limiting membrane and the outer plexiform layer was about 1.7 times thicker than the corresponding thickness of WT rabbits in the OCT images. This thickening was caused by a marked gliosis of the entire retina which was confirmed by light and transmission electron microscopy. In addition, immunohistochemical analysis showed there was excessive staining of the glial fibrillary acid protein in the older P347L Tg rabbits although the rod ON bipolar cells and horizontal cells were still present in the inner nuclear layer. Our results indicate that the P347L Tg rabbit progressed to complete photoreceptor loss within 30- and 54-months-of-age and severe gliosis altered the morphology of the retina.
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Affiliation(s)
- Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
| | - Taro Kominami
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Satoshi Okado
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Daiki Inooka
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Ganjawala TH, Lu Q, Fenner MD, Abrams GW, Pan ZH. Improved CoChR Variants Restore Visual Acuity and Contrast Sensitivity in a Mouse Model of Blindness under Ambient Light Conditions. Mol Ther 2019; 27:1195-1205. [PMID: 31010741 DOI: 10.1016/j.ymthe.2019.04.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 04/03/2019] [Accepted: 04/03/2019] [Indexed: 11/15/2022] Open
Abstract
Severe photoreceptor cell death in retinal degenerative diseases leads to partial or complete blindness. Optogenetics is a promising strategy to treat blindness. The feasibility of this strategy has been demonstrated through the ectopic expression of microbial channelrhodopsins (ChRs) and other genetically encoded light sensors in surviving retinal neurons in animal models. A major drawback for ChR-based visual restoration is low light sensitivity. Here, we report the development of highly operational light-sensitive ChRs by optimizing the kinetics of a recently reported ChR variant, Chloromonas oogama (CoChR). In particular, we identified two CoChR mutants, CoChR-L112C and CoChR-H94E/L112C/K264T, with markedly enhanced light sensitivity. The improved light sensitivity of the CoChR mutants was confirmed by ex vivo electrophysiological recordings in the retina. Furthermore, the CoChR mutants restored the vision of a blind mouse model under ambient light conditions with remarkably good contrast sensitivity and visual acuity, as evidenced by the results of behavioral assays. The ability to restore functional vision under normal light conditions with the improved CoChR variants removed a major obstacle for ChR-based optogenetic vision restoration.
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Affiliation(s)
- Tushar H Ganjawala
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Qi Lu
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Mitchell D Fenner
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Gary W Abrams
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Zhuo-Hua Pan
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA.
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Affiliation(s)
- Eunkyoung Park
- Smart Healthcare & Device Research Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyu-Sung Lee
- Smart Healthcare & Device Research Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.,Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Seoul, Korea.,Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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