1
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Yazdan-Shahmorad P, Gibson S, Lee JC, Horwitz GD. Preferential transduction of parvalbumin-expressing cortical neurons by AAV-mDLX5/6 vectors. Front Neurosci 2024; 17:1269025. [PMID: 38410819 PMCID: PMC10894992 DOI: 10.3389/fnins.2023.1269025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/28/2023] [Indexed: 02/28/2024] Open
Abstract
A major goal of modern neuroscience is to understand the functions of the varied neuronal types that comprise the mammalian brain. Toward this end, some types of neurons can be targeted and manipulated with enhancer-bearing AAV vectors. These vectors hold great promise to advance basic and translational neuroscience, but to realize this potential, their selectivity must be characterized. In this study, we investigated the selectivity of AAV vectors carrying an enhancer of the murine Dlx5 and Dlx6 genes. Vectors were injected into the visual cortex of two macaque monkeys, the frontal cortex of two others, and the somatosensory/motor cortex of three rats. Post-mortem immunostaining revealed that parvalbumin-expressing neurons were transduced efficiently in all cases but calretinin-expressing neurons were not. We speculate that this specificity is a consequence of differential activity of this DLX5/6 enhancer in adult neurons of different developmental lineages.
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Affiliation(s)
- Padideh Yazdan-Shahmorad
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, United States
- Washington National Primate Research Center, Seattle, WA, United States
| | - Shane Gibson
- Washington National Primate Research Center, Seattle, WA, United States
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - Joanne C Lee
- Washington National Primate Research Center, Seattle, WA, United States
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - Gregory D Horwitz
- Washington National Primate Research Center, Seattle, WA, United States
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
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2
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He X, Fu Y, Ma L, Yao Y, Ge S, Yang Z, Fan X. AAV for Gene Therapy in Ocular Diseases: Progress and Prospects. RESEARCH (WASHINGTON, D.C.) 2023; 6:0291. [PMID: 38188726 PMCID: PMC10768554 DOI: 10.34133/research.0291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 11/27/2023] [Indexed: 01/09/2024]
Abstract
Owing to the promising therapeutic effect and one-time treatment advantage, gene therapy may completely change the management of eye diseases, especially retinal diseases. Adeno-associated virus (AAV) is considered one of the most promising viral gene delivery tools because it can infect various types of tissues and is considered as a relatively safe gene delivery vector. The eye is one of the most popular organs for gene therapy, since its limited volume is suitable for small doses of AAV stably transduction. Recently, an increasing number of clinical trials of AAV-mediated gene therapy are underway. This review summarizes the biological functions of AAV and its application in the treatment of various ocular diseases, as well as the characteristics of different AAV delivery routes in clinical applications. Here, the latest research progresses in AAV-mediated gene editing and silencing strategies to modify that the genetic ocular diseases are systematically outlined, especially by base editing and prime editing. We discuss the progress of AAV in ocular optogenetic therapy. We also summarize the application of AAV-mediated gene therapy in animal models and the difficulties in its clinical transformation.
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Affiliation(s)
- Xiaoyu He
- Department of Ophthalmology, Ninth People’s Hospital,
Shanghai JiaoTong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Yidian Fu
- Department of Ophthalmology, Ninth People’s Hospital,
Shanghai JiaoTong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Liang Ma
- Department of Ophthalmology, Ninth People’s Hospital,
Shanghai JiaoTong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Yizheng Yao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University; Clinical Research Center of Neurological Disease,
The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Shengfang Ge
- Department of Ophthalmology, Ninth People’s Hospital,
Shanghai JiaoTong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Zhi Yang
- Department of Ophthalmology, Ninth People’s Hospital,
Shanghai JiaoTong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Xianqun Fan
- Department of Ophthalmology, Ninth People’s Hospital,
Shanghai JiaoTong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
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3
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Wood EH, Kreymerman A, Kowal T, Buickians D, Sun Y, Muscat S, Mercola M, Moshfeghi DM, Goldberg JL. Cellular and subcellular optogenetic approaches towards neuroprotection and vision restoration. Prog Retin Eye Res 2023; 96:101153. [PMID: 36503723 PMCID: PMC10247900 DOI: 10.1016/j.preteyeres.2022.101153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/27/2022] [Accepted: 11/28/2022] [Indexed: 12/13/2022]
Abstract
Optogenetics is defined as the combination of genetic and optical methods to induce or inhibit well-defined events in isolated cells, tissues, or animals. While optogenetics within ophthalmology has been primarily applied towards treating inherited retinal disease, there are a myriad of other applications that hold great promise for a variety of eye diseases including cellular regeneration, modulation of mitochondria and metabolism, regulation of intraocular pressure, and pain control. Supported by primary data from the authors' work with in vitro and in vivo applications, we introduce a novel approach to metabolic regulation, Opsins to Restore Cellular ATP (ORCA). We review the fundamental constructs for ophthalmic optogenetics, present current therapeutic approaches and clinical trials, and discuss the future of subcellular and signaling pathway applications for neuroprotection and vision restoration.
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Affiliation(s)
- Edward H Wood
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA; Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Alexander Kreymerman
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA; Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Tia Kowal
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - David Buickians
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Yang Sun
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Stephanie Muscat
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Mark Mercola
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Darius M Moshfeghi
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA.
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4
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Hatakeyama A, Sugano E, Sayama T, Watanabe Y, Suzuki T, Tabata K, Endo Y, Sakajiri T, Fukuda T, Ozaki T, Tomita H. Properties of a Single Amino Acid Residue in the Third Transmembrane Domain Determine the Kinetics of Ambient Light-Sensitive Channelrhodopsin. Int J Mol Sci 2023; 24:ijms24055054. [PMID: 36902480 PMCID: PMC10003734 DOI: 10.3390/ijms24055054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/02/2023] [Accepted: 03/04/2023] [Indexed: 03/09/2023] Open
Abstract
Channelrhodopsins have been utilized in gene therapy to restore vision in patients with retinitis pigmentosa and their channel kinetics are an important factor to consider in such applications. We investigated the channel kinetics of ComV1 variants with different amino acid residues at the 172nd position. Patch clamp methods were used to record the photocurrents induced by stimuli from diodes in HEK293 cells transfected with plasmid vectors. The channel kinetics (τon and τoff) were considerably altered by the replacement of the 172nd amino acid and was dependent on the amino acid characteristics. The size of amino acids at this position correlated with τon and decay, whereas the solubility correlated with τon and τoff. Molecular dynamic simulation indicated that the ion tunnel constructed by H172, E121, and R306 widened due to H172A variant, whereas the interaction between A172 and the surrounding amino acids weakened compared with H172. The bottleneck radius of the ion gate constructed with the 172nd amino acid affected the photocurrent and channel kinetics. The 172nd amino acid in ComV1 is a key residue for determining channel kinetics as its properties alter the radius of the ion gate. Our findings can be used to improve the channel kinetics of channelrhodopsins.
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5
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Nieuwenhuis B, Laperrousaz E, Tribble JR, Verhaagen J, Fawcett JW, Martin KR, Williams PA, Osborne A. Improving adeno-associated viral (AAV) vector-mediated transgene expression in retinal ganglion cells: comparison of five promoters. Gene Ther 2023:10.1038/s41434-022-00380-z. [PMID: 36635457 DOI: 10.1038/s41434-022-00380-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 12/02/2022] [Accepted: 12/21/2022] [Indexed: 01/14/2023]
Abstract
Recombinant adeno-associated viral vectors (AAVs) are an effective system for gene transfer. AAV serotype 2 (AAV2) is commonly used to deliver transgenes to retinal ganglion cells (RGCs) via intravitreal injection. The AAV serotype however is not the only factor contributing to the effectiveness of gene therapies. Promoters influence the strength and cell-selectivity of transgene expression. This study compares five promoters designed to maximise AAV2 cargo space for gene delivery: chicken β-actin (CBA), cytomegalovirus (CMV), short CMV early enhancer/chicken β-actin/short β-globulin intron (sCAG), mouse phosphoglycerate kinase (PGK), and human synapsin (SYN). The promoters driving enhanced green fluorescent protein (eGFP) were examined in adult C57BL/6J mice eyes and tissues of the visual system. eGFP expression was strongest in the retina, optic nerves and brain when driven by the sCAG and SYN promoters. CBA, CMV, and PGK had moderate expression by comparison. The SYN promoter had almost exclusive transgene expression in RGCs. The PGK promoter had predominant expression in both RGCs and AII amacrine cells. The ubiquitous CBA, CMV, and sCAG promoters expressed eGFP in a variety of cell types across multiple retinal layers including Müller glia and astrocytes. We also found that these promoters could transduce human retina ex vivo, although expression was predominantly in glial cells due to low RGC viability. Taken together, this promoter comparison study contributes to optimising AAV-mediated transduction in the retina, and could be valuable for research in ocular disorders, particularly those with large or complex genetic cargos.
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Affiliation(s)
- Bart Nieuwenhuis
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
| | - Elise Laperrousaz
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Joost Verhaagen
- Laboratory for Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands.,Centre for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - James W Fawcett
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Centre of Reconstructive Neuroscience, Institute of Experimental Medicine, Prague, Czech Republic
| | - Keith R Martin
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Andrew Osborne
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Ikarovec Ltd, The Norwich Research Park Innovation Centre, Norwich, UK.
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6
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Cojocaru AE, Corna A, Reh M, Zeck G. High spatial resolution artificial vision inferred from the spiking output of retinal ganglion cells stimulated by optogenetic and electrical means. Front Cell Neurosci 2022; 16:1033738. [PMID: 36568888 PMCID: PMC9780279 DOI: 10.3389/fncel.2022.1033738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/10/2022] [Indexed: 12/13/2022] Open
Abstract
With vision impairment affecting millions of people world-wide, various strategies aiming at vision restoration are being undertaken. Thanks to decades of extensive research, electrical stimulation approaches to vision restoration began to undergo clinical trials. Quite recently, another technique employing optogenetic therapy emerged as a possible alternative. Both artificial vision restoration strategies reported poor spatial resolution so far. In this article, we compared the spatial resolution inferred ex vivo under ideal conditions using a computational model analysis of the retinal ganglion cell (RGC) spiking activity. The RGC spiking was stimulated in epiretinal configuration by either optogenetic or electrical means. RGCs activity was recorded from the ex vivo retina of transgenic late-stage photoreceptor-degenerated mice (rd10) using a high-density Complementary Metal Oxide Semiconductor (CMOS) based microelectrode array. The majority of retinal samples were stimulated by both, optogenetic and electrical stimuli using a spatial grating stimulus. A population-level analysis of the spiking activity of identified RGCs was performed and the spatial resolution achieved through electrical and optogenetic photo-stimulation was inferred using a support vector machine classifier. The best f1 score of the classifier for the electrical stimulation in epiretinal configuration was 86% for 32 micron wide gratings and increased to 100% for 128 microns. For optogenetically activated cells, we obtained high f1 scores of 82% for 10 microns grid width for a photo-stimulation frequency of 2.5 Hz and 73% for a photo-stimulation frequency of 10 Hz. A subsequent analysis, considering only the RGCs modulated in both electrical and optogenetic stimulation protocols revealed no significant difference in the prediction accuracy between the two stimulation modalities. The results presented here indicate that a high spatial resolution can be achieved for electrical or optogenetic artificial stimulation using the activated retinal ganglion cell output.
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Affiliation(s)
| | - Andrea Corna
- Institute of Biomedical Electronics, TU Wien, Vienna, Austria
| | - Miriam Reh
- Institute for Ophthalmic Research at the University of Tübingen, Tübingen, Germany
| | - Günther Zeck
- Institute of Biomedical Electronics, TU Wien, Vienna, Austria
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7
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Optogenetic Therapy for Visual Restoration. Int J Mol Sci 2022; 23:ijms232315041. [PMID: 36499371 PMCID: PMC9735806 DOI: 10.3390/ijms232315041] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
Optogenetics is a recent breakthrough in neuroscience, and one of the most promising applications is the treatment of retinal degenerative diseases. Multiple clinical trials are currently ongoing, less than a decade after the first attempt at visual restoration using optogenetics. Optogenetic therapy has great value in providing hope for visual restoration in late-stage retinal degeneration, regardless of the genotype. This alternative gene therapy consists of multiple elements including the choice of target retinal cells, optogenetic tools, and gene delivery systems. Currently, there are various options for each element, all of which have been developed as a product of technological success. In particular, the performance of optogenetic tools in terms of light and wavelength sensitivity have been improved by engineering microbial opsins and applying human opsins. To provide better post-treatment vision, the optimal choice of optogenetic tools and effective gene delivery to retinal cells is necessary. In this review, we provide an overview of the advancements in optogenetic therapy for visual restoration, focusing on available options for optogenetic tools and gene delivery methods.
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8
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De Silva SR, Moore AT. Optogenetic approaches to therapy for inherited retinal degenerations. J Physiol 2022; 600:4623-4632. [PMID: 35908243 DOI: 10.1113/jp282076] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 07/18/2022] [Indexed: 01/07/2023] Open
Abstract
Inherited retinal degenerations such as retinitis pigmentosa (RP) affect around one in 4000 people and are the leading cause of blindness in working age adults in several countries. In these typically monogenic conditions, there is progressive degeneration of photoreceptors; however, inner retinal neurons such as bipolar cells and ganglion cells remain largely structurally intact, even in end-stage disease. Therapeutic approaches aiming to stimulate these residual cells, independent of the underlying genetic cause, could potentially restore visual function in patients with advanced vision loss, and benefit many more patients than therapies directed at the specific gene implicated in each disorder. One approach investigated for this purpose is that of optogenetics, a method of neuromodulation that utilises light to activate neurons engineered to ectopically express a light-sensitive protein. Using gene therapy via adeno-associated viral vectors, a range of photosensitive proteins have been expressed in remaining retinal cells in advanced retinal degeneration with in vivo studies demonstrating restoration of visual function. Developing an effective optogenetic strategy requires consideration of multiple factors, including the light-sensitive protein that is used, the vector and method for gene delivery, and the target cell for expression because these in turn may affect the quality of vision that can be restored. Currently, at least four clinical trials are ongoing to investigate optogenetic therapies in patients, with the ultimate aim of reversing visual loss in end-stage disease.
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Affiliation(s)
- Samantha R De Silva
- Oxford Eye Hospital, Oxford, UK.,UCL Institute of Ophthalmology, London, UK.,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Anthony T Moore
- UCL Institute of Ophthalmology, London, UK.,Ophthalmology Department, University of California, San Francisco, CA, USA
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9
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Emiliani V, Entcheva E, Hedrich R, Hegemann P, Konrad KR, Lüscher C, Mahn M, Pan ZH, Sims RR, Vierock J, Yizhar O. Optogenetics for light control of biological systems. NATURE REVIEWS. METHODS PRIMERS 2022; 2:55. [PMID: 37933248 PMCID: PMC10627578 DOI: 10.1038/s43586-022-00136-4] [Citation(s) in RCA: 91] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/30/2022] [Indexed: 11/08/2023]
Abstract
Optogenetic techniques have been developed to allow control over the activity of selected cells within a highly heterogeneous tissue, using a combination of genetic engineering and light. Optogenetics employs natural and engineered photoreceptors, mostly of microbial origin, to be genetically introduced into the cells of interest. As a result, cells that are naturally light-insensitive can be made photosensitive and addressable by illumination and precisely controllable in time and space. The selectivity of expression and subcellular targeting in the host is enabled by applying control elements such as promoters, enhancers and specific targeting sequences to the employed photoreceptor-encoding DNA. This powerful approach allows precise characterization and manipulation of cellular functions and has motivated the development of advanced optical methods for patterned photostimulation. Optogenetics has revolutionized neuroscience during the past 15 years and is primed to have a similar impact in other fields, including cardiology, cell biology and plant sciences. In this Primer, we describe the principles of optogenetics, review the most commonly used optogenetic tools, illumination approaches and scientific applications and discuss the possibilities and limitations associated with optogenetic manipulations across a wide variety of optical techniques, cells, circuits and organisms.
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Affiliation(s)
- Valentina Emiliani
- Wavefront Engineering Microscopy Group, Photonics Department, Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Emilia Entcheva
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Rainer Hedrich
- Julius-von-Sachs Institute for Biosciences, Molecular Plant Physiology and Biophysics, University of Wuerzburg, Wuerzburg, Germany
| | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt-Universitaet zu Berlin, Berlin, Germany
| | - Kai R. Konrad
- Julius-von-Sachs Institute for Biosciences, Molecular Plant Physiology and Biophysics, University of Wuerzburg, Wuerzburg, Germany
| | - Christian Lüscher
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Clinic of Neurology, Department of Clinical Neurosciences, Geneva University Hospital, Geneva, Switzerland
| | - Mathias Mahn
- Department of Neurobiology, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Zhuo-Hua Pan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ruth R. Sims
- Wavefront Engineering Microscopy Group, Photonics Department, Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Johannes Vierock
- Institute for Biology, Experimental Biophysics, Humboldt-Universitaet zu Berlin, Berlin, Germany
- Neuroscience Research Center, Charité – Universitaetsmedizin Berlin, Berlin, Germany
| | - Ofer Yizhar
- Departments of Brain Sciences and Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
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10
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Lindner M, Gilhooley MJ, Hughes S, Hankins MW. Optogenetics for visual restoration: From proof of principle to translational challenges. Prog Retin Eye Res 2022; 91:101089. [PMID: 35691861 DOI: 10.1016/j.preteyeres.2022.101089] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 01/04/2023]
Abstract
Degenerative retinal disorders are a diverse family of diseases commonly leading to irreversible photoreceptor death, while leaving the inner retina relatively intact. Over recent years, innovative gene replacement therapies aiming to halt the progression of certain inherited retinal disorders have made their way into clinics. By rendering surviving retinal neurons light sensitive optogenetic gene therapy now offers a feasible treatment option that can restore lost vision, even in late disease stages and widely independent of the underlying cause of degeneration. Since proof-of-concept almost fifteen years ago, this field has rapidly evolved and a detailed first report on a treated patient has recently been published. In this article, we provide a review of optogenetic approaches for vision restoration. We discuss the currently available optogenetic tools and their relative advantages and disadvantages. Possible cellular targets will be discussed and we will address the question how retinal remodelling may affect the choice of the target and to what extent it may limit the outcomes of optogenetic vision restoration. Finally, we will analyse the evidence for and against optogenetic tool mediated toxicity and will discuss the challenges associated with clinical translation of this promising therapeutic concept.
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Affiliation(s)
- Moritz Lindner
- The Nuffield Laboratory of Ophthalmology, Jules Thorn SCNi, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3QU, United Kingdom; Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps University, 35037, Marburg, Germany
| | - Michael J Gilhooley
- The Nuffield Laboratory of Ophthalmology, Jules Thorn SCNi, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3QU, United Kingdom; The Institute of Ophthalmology, University College London, EC1V 9EL, United Kingdom; Moorfields Eye Hospital, London, EC1V 2PD, United Kingdom
| | - Steven Hughes
- The Nuffield Laboratory of Ophthalmology, Jules Thorn SCNi, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Mark W Hankins
- The Nuffield Laboratory of Ophthalmology, Jules Thorn SCNi, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3QU, United Kingdom.
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11
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Chaffiol A, Provansal M, Joffrois C, Blaize K, Labernede G, Goulet R, Burban E, Brazhnikova E, Duebel J, Pouget P, Sahel JA, Picaud S, Arcizet F, Gauvain G. In vivo optogenetic stimulation of the primate retina activates the visual cortex after long-term transduction. Mol Ther Methods Clin Dev 2022; 24:1-10. [PMID: 34977267 PMCID: PMC8671818 DOI: 10.1016/j.omtm.2021.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/19/2021] [Indexed: 11/26/2022]
Abstract
Over the last 15 years, optogenetics has changed fundamental research in neuroscience and is now reaching toward therapeutic applications. Vision restoration strategies using optogenetics are now at the forefront of these new clinical opportunities. But applications to human patients suffering from retinal diseases leading to blindness raise important concerns on the long-term functional expression of optogenes and the efficient signal transmission to higher visual centers. Here, we demonstrate in non-human primates continued expression and functionality at the retina level ∼20 months after delivery of our construct. We also performed in vivo recordings of visually evoked potentials in the primary visual cortex of anesthetized animals. Using synaptic blockers, we isolated the in vivo cortical activation resulting from the direct optogenetic stimulation of primate retina. In conclusion, our work indicates long-term transgene expression and transmission of the signal generated in the macaque retina to the visual cortex, two important features for future clinical applications.
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Affiliation(s)
- Antoine Chaffiol
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Matthieu Provansal
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Corentin Joffrois
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Kévin Blaize
- Institut de Neurosciences de la Timone, UMR 7289 Centre National de la Recherche Scientifique and Aix-Marseille Université, 13385 Marseille Cedex 05, France
| | - Guillaume Labernede
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Ruben Goulet
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Emma Burban
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Elena Brazhnikova
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Jens Duebel
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | - Pierre Pouget
- INSERM 1127, CNRS 7225, Institut du Cerveau et de la Moelle Épinière, Sorbonne Université, 75013 Paris, France
| | - José Alain Sahel
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Serge Picaud
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Fabrice Arcizet
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
| | - Gregory Gauvain
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 75012 Paris, France
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12
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Provansal M, Marazova K, Sahel JA, Picaud S. Vision Restoration by Optogenetic Therapy and Developments Toward Sonogenetic Therapy. Transl Vis Sci Technol 2022; 11:18. [PMID: 35024784 PMCID: PMC8762673 DOI: 10.1167/tvst.11.1.18] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 11/24/2022] Open
Abstract
After revolutionizing neuroscience, optogenetic therapy has entered successfully in clinical trials for restoring vision to blind people with degenerative eye diseases, such as retinitis pigmentosa. These clinical trials still have to evaluate the visual acuity achieved by patients and to determine if it reaches its theoretical limit extrapolated from ex vivo experiments. Different strategies are developed in parallel to reduce required light levels and improve information processing by targeting various cell types. For patients with vision loss due to optic atrophy, as in the case of glaucoma, optogenetic cortical stimulation is hampered by light absorption and scattering by the brain tissue. By contrast, ultrasound waves can diffuse widely through the dura mater and the brain tissue as indicated by ultrasound imaging. Based on our recent results in rodents, we propose the sonogenetic therapy relying on activation of the mechanosensitive channel as a very promising vision restoration strategy with a suitable spatiotemporal resolution. Genomic approaches may thus provide efficient brain machine interfaces for sight restoration.
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Affiliation(s)
| | - Katia Marazova
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - José Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Centre Hospitalier National d'Ophtalmologie des XV-XX, Paris, France
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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13
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Lopez-Gordo E, Orlowski A, Wang A, Weinberg A, Sahoo S, Weber T. Hydroxylation of N-acetylneuraminic Acid Influences the in vivo Tropism of N-linked Sialic Acid-Binding Adeno-Associated Viruses AAV1, AAV5, and AAV6. Front Med (Lausanne) 2021; 8:732095. [PMID: 35036407 PMCID: PMC8757481 DOI: 10.3389/fmed.2021.732095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Adeno-associated virus (AAV) vectors are promising candidates for gene therapy. However, a number of recent preclinical large animal studies failed to translate into the clinic. This illustrates the formidable challenge of choosing the animal models that promise the best chance of a successful translation into the clinic. Several of the most common AAV serotypes use sialic acid (SIA) as their primary receptor. However, in contrast to most mammals, humans lack the enzyme CMAH, which hydroxylates cytidine monophosphate-N-acetylneuraminic acid (CMP-Neu5Ac) into cytidine monophosphate-N-glycolylneuraminic acid (CMP-Neu5Gc). As a result, human glycans only contain Neu5Ac and not Neu5Gc. Here, we investigate the tropism of AAV1, 5, 6 and 9 in wild-type C57BL/6J (WT) and CMAH knock-out (CMAH−/−) mice. All N-linked SIA-binding serotypes (AAV1, 5 and 6) showed significantly lower transduction of the heart in CMAH−/− when compared to WT mice (5–5.8-fold) and, strikingly, skeletal muscle transduction by AAV5 was almost 30-fold higher in CMAH−/− compared to WT mice. Importantly, the AAV tropism or distribution of expression among different organs was also affected. For AAV1, AAV5 and AAV6, expression in the heart compared to the liver was 4.6–8-fold higher in WT than in CMAH−/− mice, and for AAV5 the expression in the heart compared to the skeletal muscle was 57.3-fold higher in WT than in CMAH−/− mice. These data thus strongly suggest that the relative abundance of Neu5Ac and Neu5Gc plays a role in AAV tropism, and that results obtained in commonly used animal models might not translate into the clinic.
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Affiliation(s)
- Estrella Lopez-Gordo
- Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
| | - Alejandro Orlowski
- Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
| | - Arthur Wang
- Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
| | - Alan Weinberg
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
| | - Susmita Sahoo
- Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
| | - Thomas Weber
- Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
- *Correspondence: Thomas Weber
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14
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Moraru AD, Costin D, Iorga RE, Munteanu M, Moraru RL, Branisteanu DC. Current trends in gene therapy for retinal diseases (Review). Exp Ther Med 2021; 23:26. [PMID: 34815778 PMCID: PMC8593927 DOI: 10.3892/etm.2021.10948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/10/2021] [Indexed: 11/17/2022] Open
Abstract
The eye is considered an effective target for genetic therapy, as it has a privileged immune status, it is easily accessed for medication delivery and it is affected by a number of inherited disorders. In particular, the retina is considered for gene therapy due to the fact that it can be visualized with ease, it does not have lymphatic vessels, nor a direct blood network for the outer layers and its cells do not divide after birth, and thus transgene expression is not affected. As gene therapy is currently on a continuously progressive development trend, this emerging field of gene manipulation techniques has yielded promising results. This involves the development of treatments for a number of debilitating and blinding diseases, which were to date considered intractable. However, numerous unanswered questions remain as regards the long-term efficacy and safety profile of these treatments. The present review article discusses the current research status regarding genetic manipulation techniques aimed at addressing visual impairment related to retinal disorders, both inherited and degenerative.
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Affiliation(s)
- Andreea Dana Moraru
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'N. Oblu' Clinical Hospital, 700309 Iași, Romania
| | - Dănuț Costin
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'N. Oblu' Clinical Hospital, 700309 Iași, Romania
| | - Raluca Eugenia Iorga
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'N. Oblu' Clinical Hospital, 700309 Iași, Romania
| | - Mihnea Munteanu
- Department of Ophthalmology, 'Victor Babeș' University of Medicine and Pharmacy, 300041 Timișoara, Romania
| | - Radu Lucian Moraru
- Department of Otorhinolaryngology, 'Transmed Expert' Medical Center, 700011 Iași, Romania
| | - Daniel Constantin Branisteanu
- Department of Ophthalmology, 'Grigore T. Popa' University of Medicine and Pharmacy, 700115 Iași, Romania.,Department of Ophthalmology, 'Retina Center' Eye Clinic, 700126 Iași, Romania
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15
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Martinez Velazquez LA, Ballios BG. The Next Generation of Molecular and Cellular Therapeutics for Inherited Retinal Disease. Int J Mol Sci 2021; 22:ijms222111542. [PMID: 34768969 PMCID: PMC8583900 DOI: 10.3390/ijms222111542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 12/26/2022] Open
Abstract
Inherited retinal degenerations (IRDs) are a diverse group of conditions that are often characterized by the loss of photoreceptors and blindness. Recent innovations in molecular biology and genomics have allowed us to identify the causative defects behind these dystrophies and to design therapeutics that target specific mechanisms of retinal disease. Recently, the FDA approved the first in vivo gene therapy for one of these hereditary blinding conditions. Current clinical trials are exploring new therapies that could provide treatment for a growing number of retinal dystrophies. While the field has had early success with gene augmentation strategies for treating retinal disease based on loss-of-function mutations, many novel approaches hold the promise of offering therapies that span the full spectrum of causative mutations and mechanisms. Here, we provide a comprehensive review of the approaches currently in development including a discussion of retinal neuroprotection, gene therapies (gene augmentation, gene editing, RNA modification, optogenetics), and regenerative stem or precursor cell-based therapies. Our review focuses on technologies that are being developed for clinical translation or are in active clinical trials and discusses the advantages and limitations for each approach.
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Affiliation(s)
| | - Brian G. Ballios
- Department of Ophthalmology and Vision Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5T 3A9, Canada
- Correspondence:
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16
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Development of an optogenetic gene sensitive to daylight and its implications in vision restoration. NPJ Regen Med 2021; 6:64. [PMID: 34650094 PMCID: PMC8516861 DOI: 10.1038/s41536-021-00177-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/29/2021] [Indexed: 11/14/2022] Open
Abstract
Optogenetic gene-mediated therapy for restoring vision is thought to be a useful treatment for blind patients. However, light sensitivity achieved using this gene therapy is inferior to that of daylight vision. To increase light sensitivity, we designed three mutants using a bioinformatics approach. Nucleotide sequences encoding two sites in the extracellular loops (ex1, ex3) of mVChR1 close to simulated ion-conducting pathways were replaced by homologous amino acid-encoding sequences of ChR1 or ChR2. The light sensitivity of ex3mV1 was higher than that of mVChR1 at 405–617 nm. Visual responses were restored in Royal College of Surgeons rats with genetically degenerating photoreceptor cells transfected with ex3mV1Co, wherein transmembrane of sixth (TM6) in ex3mV1 was additionally replaced with the corresponding domain of CoChR; these rats responded to light in the order of μW/mm2. Thus, ex3mV1Co might be useful for the restoration of advanced visual function.
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17
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Grünert U, Martin PR. Morphology, Molecular Characterization, and Connections of Ganglion Cells in Primate Retina. Annu Rev Vis Sci 2021; 7:73-103. [PMID: 34524877 DOI: 10.1146/annurev-vision-100419-115801] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The eye sends information about the visual world to the brain on over 20 parallel signal pathways, each specialized to signal features such as spectral reflection (color), edges, and motion of objects in the environment. Each pathway is formed by the axons of a separate type of retinal output neuron (retinal ganglion cell). In this review, we summarize what is known about the excitatory retinal inputs, brain targets, and gene expression patterns of ganglion cells in humans and nonhuman primates. We describe how most ganglion cell types receive their input from only one or two of the 11 types of cone bipolar cell and project selectively to only one or two target regions in the brain. We also highlight how genetic methods are providing tools to characterize ganglion cells and establish cross-species homologies.
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Affiliation(s)
- Ulrike Grünert
- Save Sight Institute, Faculty of Medicine and Health, The University of Sydney, Sydney NSW 2000, Australia; , .,Sydney Node, Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney NSW 2000, Australia
| | - Paul R Martin
- Save Sight Institute, Faculty of Medicine and Health, The University of Sydney, Sydney NSW 2000, Australia; , .,Sydney Node, Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney NSW 2000, Australia
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18
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Xu D, Khan MA, Klufas MA, Ho AC. Administration of Ocular Gene Therapy. Int Ophthalmol Clin 2021; 61:131-149. [PMID: 34196321 DOI: 10.1097/iio.0000000000000365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Gauvain G, Akolkar H, Chaffiol A, Arcizet F, Khoei MA, Desrosiers M, Jaillard C, Caplette R, Marre O, Bertin S, Fovet CM, Demilly J, Forster V, Brazhnikova E, Hantraye P, Pouget P, Douar A, Pruneau D, Chavas J, Sahel JA, Dalkara D, Duebel J, Benosman R, Picaud S. Optogenetic therapy: high spatiotemporal resolution and pattern discrimination compatible with vision restoration in non-human primates. Commun Biol 2021; 4:125. [PMID: 33504896 PMCID: PMC7840970 DOI: 10.1038/s42003-020-01594-w] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 12/09/2020] [Indexed: 01/06/2023] Open
Abstract
Vision restoration is an ideal medical application for optogenetics, because the eye provides direct optical access to the retina for stimulation. Optogenetic therapy could be used for diseases involving photoreceptor degeneration, such as retinitis pigmentosa or age-related macular degeneration. We describe here the selection, in non-human primates, of a specific optogenetic construct currently tested in a clinical trial. We used the microbial opsin ChrimsonR, and showed that the AAV2.7m8 vector had a higher transfection efficiency than AAV2 in retinal ganglion cells (RGCs) and that ChrimsonR fused to tdTomato (ChR-tdT) was expressed more efficiently than ChrimsonR. Light at 600 nm activated RGCs transfected with AAV2.7m8 ChR-tdT, from an irradiance of 1015 photons.cm−2.s−1. Vector doses of 5 × 1010 and 5 × 1011 vg/eye transfected up to 7000 RGCs/mm2 in the perifovea, with no significant immune reaction. We recorded RGC responses from a stimulus duration of 1 ms upwards. When using the recorded activity to decode stimulus information, we obtained an estimated visual acuity of 20/249, above the level of legal blindness (20/400). These results lay the groundwork for the ongoing clinical trial with the AAV2.7m8 - ChR-tdT vector for vision restoration in patients with retinitis pigmentosa. Gauvain et al demonstrate that optogenetic therapy using the AAV2.7m8- ChR-tdT construct can partially restore vision in non-human primates to levels above those considered legally-blind. This study enables the identification of the most suitable construct for ongoing clinical trials attempting vision restoration in patients with retinitis pigmentosa.
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Affiliation(s)
- Gregory Gauvain
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.
| | - Himanshu Akolkar
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.,Department of Ophthalmology, University Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Antoine Chaffiol
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Fabrice Arcizet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Mina A Khoei
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Mélissa Desrosiers
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Céline Jaillard
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Romain Caplette
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Olivier Marre
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Stéphane Bertin
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, F-75012, Paris, France
| | - Claire-Maelle Fovet
- Département des Sciences du Vivant (DSV), MIRcen, Institut d'imagerie Biomédicale (I2BM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), 92260, Fontenay-aux-Roses, France
| | - Joanna Demilly
- Département des Sciences du Vivant (DSV), MIRcen, Institut d'imagerie Biomédicale (I2BM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), 92260, Fontenay-aux-Roses, France
| | - Valérie Forster
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Elena Brazhnikova
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Philippe Hantraye
- Département des Sciences du Vivant (DSV), MIRcen, Institut d'imagerie Biomédicale (I2BM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), 92260, Fontenay-aux-Roses, France
| | - Pierre Pouget
- ICM, UMRS 1127 UPMC - U 1127 INSERM - UMR 7225 CNRS, Paris, France
| | - Anne Douar
- Gensight Biologics, 74 rue du faubourg Saint Antoine, F-75012, Paris, France
| | - Didier Pruneau
- Gensight Biologics, 74 rue du faubourg Saint Antoine, F-75012, Paris, France
| | - Joël Chavas
- Gensight Biologics, 74 rue du faubourg Saint Antoine, F-75012, Paris, France
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.,Department of Ophthalmology, University Pittsburgh Medical Center, Pittsburgh, PA, USA.,CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, F-75012, Paris, France
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Jens Duebel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Ryad Benosman
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.,Department of Ophthalmology, University Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.
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20
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Xu D, Khan MA, Ho AC. Creating an Ocular Biofactory: Surgical Approaches in Gene Therapy for Acquired Retinal Diseases. Asia Pac J Ophthalmol (Phila) 2021; 10:5-11. [PMID: 33399391 DOI: 10.1097/apo.0000000000000362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
ABSTRACT Gene therapy offers the potential to treat inherited retinal disorders and deliver sustained therapy for acquired retinal diseases. In the latter case, host cells can be harnessed to produce non-native proteins that have beneficial properties, such as antivascular endothelial growth factor activity, transforming the eye into an ocular "biofactory." Several gene therapy programs have entered clinical testing for delivery to the vitreous, subretinal, and suprachoroidal space. Improved viral vectors and refined surgical techniques are critical to successful delivery of therapeutic products to the target tissue. In this review, we discuss the development of gene therapy products aimed at acquired retinal diseases and the surgical techniques utilized to achieve targeted delivery.
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Affiliation(s)
- David Xu
- Retina Service, Wills Eye Hospital, Philadelphia, PA
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21
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McClements ME, Staurenghi F, MacLaren RE, Cehajic-Kapetanovic J. Optogenetic Gene Therapy for the Degenerate Retina: Recent Advances. Front Neurosci 2020; 14:570909. [PMID: 33262683 PMCID: PMC7686539 DOI: 10.3389/fnins.2020.570909] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/23/2020] [Indexed: 12/18/2022] Open
Abstract
The degeneration of light-detecting rod and cone photoreceptors in the human retina leads to severe visual impairment and ultimately legal blindness in millions of people worldwide. Multiple therapeutic options at different stages of degeneration are being explored but the majority of ongoing clinical trials involve adeno-associated viral (AAV) vector-based gene supplementation strategies for select forms of inherited retinal disease. Over 300 genes are associated with inherited retinal degenerations and only a small proportion of these will be suitable for gene replacement therapy. However, while the origins of disease may vary, there are considerable similarities in the physiological changes that occur in the retina. When early therapeutic intervention is not possible and patients suffer loss of photoreceptor cells but maintain remaining layers of cells in the neural retina, there is an opportunity for a universal gene therapy approach that can be applied regardless of the genetic origin of disease. Optogenetic therapy offers such a strategy by aiming to restore vision though the provision of light-sensitive molecules to surviving cell types of the retina that enable light perception through the residual neurons. Here we review the recent progress in attempts to restore visual function to the degenerate retina using optogenetic therapy. We focus on multiple pre-clinical models used in optogenetic strategies, discuss their strengths and limitations, and highlight considerations including vector and transgene designs that have advanced the field into two ongoing clinical trials.
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Affiliation(s)
- Michelle E. McClements
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Federica Staurenghi
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Robert E. MacLaren
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
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22
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Kleinlogel S, Vogl C, Jeschke M, Neef J, Moser T. Emerging approaches for restoration of hearing and vision. Physiol Rev 2020; 100:1467-1525. [DOI: 10.1152/physrev.00035.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Impairments of vision and hearing are highly prevalent conditions limiting the quality of life and presenting a major socioeconomic burden. For long, retinal and cochlear disorders have remained intractable for causal therapies, with sensory rehabilitation limited to glasses, hearing aids, and electrical cochlear or retinal implants. Recently, the application of gene therapy and optogenetics to eye and ear has generated hope for a fundamental improvement of vision and hearing restoration. To date, one gene therapy for the restoration of vision has been approved and undergoing clinical trials will broaden its application including gene replacement, genome editing, and regenerative approaches. Moreover, optogenetics, i.e. controlling the activity of cells by light, offers a more general alternative strategy. Over little more than a decade, optogenetic approaches have been developed and applied to better understand the function of biological systems, while protein engineers have identified and designed new opsin variants with desired physiological features. Considering potential clinical applications of optogenetics, the spotlight is on the sensory systems. Multiple efforts have been undertaken to restore lost or hampered function in eye and ear. Optogenetic stimulation promises to overcome fundamental shortcomings of electrical stimulation, namely poor spatial resolution and cellular specificity, and accordingly to deliver more detailed sensory information. This review aims at providing a comprehensive reference on current gene therapeutic and optogenetic research relevant to the restoration of hearing and vision. We will introduce gene-therapeutic approaches and discuss the biotechnological and optoelectronic aspects of optogenetic hearing and vision restoration.
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Affiliation(s)
| | | | | | | | - Tobias Moser
- Institute for Auditory Neuroscience, University Medical Center Goettingen, Germany
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23
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Abstract
Developments of new strategies to restore vision and improving on current strategies by harnessing new advancements in material and electrical sciences, and biological and genetic-based technologies are of upmost health priorities around the world. Federal and private entities are spending billions of dollars on visual prosthetics technologies. This review describes the most current and state-of-the-art bioengineering technologies to restore vision. This includes a thorough description of traditional electrode-based visual prosthetics that have improved substantially since early prototypes. Recent advances in molecular and synthetic biology have transformed vision-assisted technologies; For example, optogenetic technologies that introduce light-responsive proteins offer excellent resolution but cortical applications are restricted by fiber implantation and tissue damage. Other stimulation modalities, such as magnetic fields, have been explored to achieve non-invasive neuromodulation. Miniature magnetic coils are currently being developed to activate select groups of neurons. Magnetically-responsive nanoparticles or exogenous proteins can significantly enhance the coupling between external electromagnetic devices and any neurons affiliated with these modifications. The need to minimize cytotoxic effects for nanoparticle-based therapies will likely restrict the number of usable materials. Nevertheless, advances in identifying and utilizing proteins that respond to magnetic fields may lead to non-invasive, cell-specific stimulation and may overcome many of the limitations that currently exist with other methods. Finally, sensory substitution systems also serve as viable visual prostheses by converting visual input to auditory and somatosensory stimuli. This review also discusses major challenges in the field and offers bioengineering strategies to overcome those.
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Affiliation(s)
- Alexander Farnum
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI, United States
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Galit Pelled
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI, United States
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
- Department of Radiology, College of Human Medicine, Michigan State University, East Lansing, MI, United States
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24
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Abstract
Retinal degenerative diseases caused by photoreceptor cell death are major causes of irreversible vision loss. As only primates have a macula, the nonhuman primate (NHP) models have a crucial role not only in revealing biological mechanisms underlying high-acuity vision but also in the development of therapies. Successful translation of basic research findings into clinical trials and, moreover, approval of the first therapies for blinding inherited and age-related retinal dystrophies has been reported in recent years. This article explores the value of the NHP models in understanding human vision and reviews their contribution to the development of innovative therapeutic strategies to save and restore vision.
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25
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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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26
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Abstract
In humans high quality, high acuity visual experience is mediated by the fovea, a tiny, specialized patch of retina containing the locus of fixation. Despite this, vision restoration strategies are typically developed in animal models without a fovea. While electrical prostheses have been approved by regulators, as yet they have failed to restore high quality, high acuity vision in patients. Approaches under pre-clinical development include regenerative cell therapies, optogenetics and chemical photosensitizers. All retinal vision restoration therapies require reactivation of inner retina that has lost photoreceptor input and that the restored signals can be interpreted at a behavioural level. A greater emphasis on tackling these challenges at the fovea may accelerate progress toward high quality vision restoration.
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Affiliation(s)
- Juliette E McGregor
- Center for Visual Science, University of Rochester, 601 Crittenden Blvd, Rochester, New York, USA
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Abstract
Visual prostheses serve to restore visual function following acquired blindness. Acquired blindness (as opposed to congenital blindness) has many causes, including diseases such as retinitis pigmentosa, glaucoma, and macular degeneration, or trauma such as caused by automobile accident or blast damage from explosions. Many of the blindness-causing diseases target the retina or other ocular structure. Often, despite the loss of sensitivity to light, the remainder of the visual pathway is still functional, enabling electrical devices to deliver effective and meaningful visual information to the brain via arrays of electrodes. These arrays can be placed in any part of the early visual pathway, such as the retina, optic nerve, lateral geniculate nucleus, or visual cortex. A camera or other imaging source is used to drive electrical stimulation of remaining healthy cells or structures to create artificial vision and provide restoration of function. In this review, each approach to visual prostheses is described, including advantages and disadvantages as well as assessments of the current state of the art. Most of the work to-date has been targeting stimulation of (a) the retina, with three devices approved for general use and two more in clinical testing; (b) the lateral geniculate nucleus, with efforts still in the pre-clinical stage; and (c) the cortex, with three devices in clinical testing and none currently approved for general use despite the longest history of investigation of the three major approaches. Each class of device has different medical indications, and different levels of invasiveness required for implantation. All contemporary devices deliver relatively poor vision. There has been remarkable progress since the first proof-of-concept demonstration that used stimulation of the primary visual cortex, with the field exploring all viable options for restoration of function. Much of the progress has been recent, driven by advances in microelectronics and biocompatibility. With three devices currently approved for general use in various parts of the world, and a handful of additional devices well along in the pipeline toward approval, prospects for wide deployment of a device-based therapy to treat acquired blindness are good.
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Wood EH, Tang PH, De la Huerta I, Korot E, Muscat S, Palanker DA, Williams GA. STEM CELL THERAPIES, GENE-BASED THERAPIES, OPTOGENETICS, AND RETINAL PROSTHETICS: Current State and Implications for the Future. Retina 2019; 39:820-835. [PMID: 30664120 PMCID: PMC6492547 DOI: 10.1097/iae.0000000000002449] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To review and discuss current innovations and future implications of promising biotechnology and biomedical offerings in the field of retina. We focus on therapies that have already emerged as clinical offerings or are poised to do so. METHODS Literature review and commentary focusing on stem cell therapies, gene-based therapies, optogenetic therapies, and retinal prosthetic devices. RESULTS The technologies discussed herein are some of the more recent promising biotechnology and biomedical developments within the field of retina. Retinal prosthetic devices and gene-based therapies both have an FDA-approved product for ophthalmology, and many other offerings (including optogenetics) are in the pipeline. Stem cell therapies offer personalized medicine through novel regenerative mechanisms but entail complex ethical and reimbursement challenges. CONCLUSION Stem cell therapies, gene-based therapies, optogenetics, and retinal prosthetic devices represent a new era of biotechnological and biomedical progress. These bring new ethical, regulatory, care delivery, and reimbursement challenges. By addressing these issues proactively, we may accelerate delivery of care to patients in a safe, efficient, and value-based manner.
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Affiliation(s)
| | - Peter H Tang
- Department of Ophthalmology, Hansen Experimental Physics Laboratory, Stanford University, Stanford, California
| | | | - Edward Korot
- Oakland University William Beaumont School of Medicine, Rochester, Michigan
| | | | - Daniel A Palanker
- Department of Ophthalmology, Hansen Experimental Physics Laboratory, Stanford University, Stanford, California
| | - George A Williams
- Associated Retinal Consultants, Royal Oak, Michigan
- Oakland University William Beaumont School of Medicine, Rochester, Michigan
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Peynshaert K, Devoldere J, Minnaert AK, De Smedt SC, Remaut K. Morphology and Composition of the Inner Limiting Membrane: Species-Specific Variations and Relevance toward Drug Delivery Research. Curr Eye Res 2019; 44:465-475. [PMID: 30638413 DOI: 10.1080/02713683.2019.1565890] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The inner limiting membrane (ILM) represents the structural boundary between the vitreous and the retina, and is suggested to act as a barrier for a wide range of retinal therapies. While it is widely acknowledged that the morphology of the human ILM exhibits regional variations and undergoes age-related changes, insight into its structure in laboratory animals is very limited. Besides presenting a detailed overview of the morphology and composition of the human ILM, this review specifically reflects on the species-specific differences in ILM structure. With these differences in mind, we furthermore summarize the most relevant reports on the barrier role of the ILM with regard to viral vectors, nanoparticles, anti-VEGF medication and stem cells. Overall, this review aims to deliberate on the impact of species-specific ILM variations on drug delivery research as well as to pinpoint knowledge gaps which future basic research should resolve.
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Affiliation(s)
- Karen Peynshaert
- a Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences , Ghent University , Ghent , Belgium.,b Ghent Research Group on Nanomedicines , Ghent University , Ghent , Belgium
| | - Joke Devoldere
- a Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences , Ghent University , Ghent , Belgium.,b Ghent Research Group on Nanomedicines , Ghent University , Ghent , Belgium
| | - An-Katrien Minnaert
- a Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences , Ghent University , Ghent , Belgium.,b Ghent Research Group on Nanomedicines , Ghent University , Ghent , Belgium
| | - Stefaan C De Smedt
- a Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences , Ghent University , Ghent , Belgium.,b Ghent Research Group on Nanomedicines , Ghent University , Ghent , Belgium
| | - Katrien Remaut
- a Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences , Ghent University , Ghent , Belgium.,b Ghent Research Group on Nanomedicines , Ghent University , Ghent , Belgium
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30
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DiCarlo JE, Mahajan VB, Tsang SH. Gene therapy and genome surgery in the retina. J Clin Invest 2018; 128:2177-2188. [PMID: 29856367 DOI: 10.1172/jci120429] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Precision medicine seeks to treat disease with molecular specificity. Advances in genome sequence analysis, gene delivery, and genome surgery have allowed clinician-scientists to treat genetic conditions at the level of their pathology. As a result, progress in treating retinal disease using genetic tools has advanced tremendously over the past several decades. Breakthroughs in gene delivery vectors, both viral and nonviral, have allowed the delivery of genetic payloads in preclinical models of retinal disorders and have paved the way for numerous successful clinical trials. Moreover, the adaptation of CRISPR-Cas systems for genome engineering have enabled the correction of both recessive and dominant pathogenic alleles, expanding the disease-modifying power of gene therapies. Here, we highlight the translational progress of gene therapy and genome editing of several retinal disorders, including RPE65-, CEP290-, and GUY2D-associated Leber congenital amaurosis, as well as choroideremia, achromatopsia, Mer tyrosine kinase- (MERTK-) and RPGR X-linked retinitis pigmentosa, Usher syndrome, neovascular age-related macular degeneration, X-linked retinoschisis, Stargardt disease, and Leber hereditary optic neuropathy.
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Affiliation(s)
- James E DiCarlo
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| | - Vinit B Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California, USA.,Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
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31
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Benfenati F, Lanzani G. New technologies for developing second generation retinal prostheses. Lab Anim (NY) 2018; 47:71-75. [PMID: 29483694 DOI: 10.1038/s41684-018-0003-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/09/2018] [Indexed: 12/25/2022]
Abstract
Inherited or age-dependent retinal dystrophies such as Retinitis pigmentosa (RP) and macular degeneration (MD) are among the most prevalent causes of blindness. Despite enormous efforts, no established pharmacological treatment to prevent or cure photoreceptor degeneration has been identified. Given the relative survival of the inner retina, attempts have been made to restore vision with optogenetics or with retinal neuroprostheses to allow light-dependent stimulation of the inner retinal network. While microelectrode and photovoltaic devices based on inorganic technologies have been proposed and in many cases implanted in RP patients, a new generation of prosthetics based on organic molecules, such as organic photoswitches and conjugated polymers, is demonstrating an unexpected potential for visual rescue and intimate interactions with functioning tissue. Organic devices are starting a new era of tissue electronics, in which light-sensitive molecules and live tissues integrate and tightly interact, producing a new ecosystem of organic prosthetics and intelligent biotic/abiotic interfaces. In addition to the retina, the applications of these interfaces might be extended in the future to other biomedical fields.
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Affiliation(s)
- Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy.
| | - Guglielmo Lanzani
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Milan, Italy
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Chaffiol A, Caplette R, Jaillard C, Brazhnikova E, Desrosiers M, Dubus E, Duhamel L, Macé E, Marre O, Benoit P, Hantraye P, Bemelmans AP, Bamberg E, Duebel J, Sahel JA, Picaud S, Dalkara D. A New Promoter Allows Optogenetic Vision Restoration with Enhanced Sensitivity in Macaque Retina. Mol Ther 2017; 25:2546-2560. [PMID: 28807567 PMCID: PMC5675708 DOI: 10.1016/j.ymthe.2017.07.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/15/2017] [Accepted: 07/16/2017] [Indexed: 01/28/2023] Open
Abstract
The majority of inherited retinal degenerations converge on the phenotype of photoreceptor cell death. Second- and third-order neurons are spared in these diseases, making it possible to restore retinal light responses using optogenetics. Viral expression of channelrhodopsin in the third-order neurons under ubiquitous promoters was previously shown to restore visual function, albeit at light intensities above illumination safety thresholds. Here, we report (to our knowledge, for the first time) activation of macaque retinas, up to 6 months post-injection, using channelrhodopsin-Ca2+-permeable channelrhodopsin (CatCh) at safe light intensities. High-level CatCh expression was achieved due to a new promoter based on the regulatory region of the gamma-synuclein gene (SNCG) allowing strong expression in ganglion cells across species. Our promoter, in combination with clinically proven adeno-associated virus 2 (AAV2), provides CatCh expression in peri-foveolar ganglion cells responding robustly to light under the illumination safety thresholds for the human eye. On the contrary, the threshold of activation and the proportion of unresponsive cells were much higher when a ubiquitous promoter (cytomegalovirus [CMV]) was used to express CatCh. The results of our study suggest that the inclusion of optimized promoters is key in the path to clinical translation of optogenetics.
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Affiliation(s)
- Antoine Chaffiol
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Romain Caplette
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Céline Jaillard
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Elena Brazhnikova
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Mélissa Desrosiers
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Elisabeth Dubus
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Laëtitia Duhamel
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Emilie Macé
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Olivier Marre
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Patrick Benoit
- Sanofi Ophthalmology Unit, 17 rue Moreau, 75012 Paris, France
| | - Philippe Hantraye
- Département des Sciences du Vivant (DSV), MIRCen, Institut d'Imagerie Biomédicale (I2BM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Fontenay-aux-Roses 92260, France; Neurodegenerative Diseases Laboratory, CNRS UMR9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses 92260, France
| | - Alexis-Pierre Bemelmans
- Département des Sciences du Vivant (DSV), MIRCen, Institut d'Imagerie Biomédicale (I2BM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Fontenay-aux-Roses 92260, France; Neurodegenerative Diseases Laboratory, CNRS UMR9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses 92260, France
| | - Ernst Bamberg
- Department of Biophysical Chemistry, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Jens Duebel
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France.
| | - José-Alain Sahel
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France; CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC, 28 rue de Charenton, 75012 Paris, France; Fondation Ophtalmologique Adolphe de Rothschild, 75019 Paris, France.
| | - Serge Picaud
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France.
| | - Deniz Dalkara
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France.
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Dias MF, Joo K, Kemp JA, Fialho SL, da Silva Cunha A, Woo SJ, Kwon YJ. Molecular genetics and emerging therapies for retinitis pigmentosa: Basic research and clinical perspectives. Prog Retin Eye Res 2017; 63:107-131. [PMID: 29097191 DOI: 10.1016/j.preteyeres.2017.10.004] [Citation(s) in RCA: 250] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 10/19/2017] [Accepted: 10/25/2017] [Indexed: 02/06/2023]
Abstract
Retinitis Pigmentosa (RP) is a hereditary retinopathy that affects about 2.5 million people worldwide. It is characterized with progressive loss of rods and cones and causes severe visual dysfunction and eventual blindness in bilateral eyes. In addition to more than 3000 genetic mutations from about 70 genes, a wide genetic overlap with other types of retinal dystrophies has been reported with RP. This diversity of genetic pathophysiology makes treatment extremely challenging. Although therapeutic attempts have been made using various pharmacologic agents (neurotrophic factors, antioxidants, and anti-apoptotic agents), most are not targeted to the fundamental cause of RP, and their clinical efficacy has not been clearly proven. Current therapies for RP in ongoing or completed clinical trials include gene therapy, cell therapy, and retinal prostheses. Gene therapy, a strategy to correct the genetic defects using viral or non-viral vectors, has the potential to achieve definitive treatment by replacing or silencing a causative gene. Among many clinical trials of gene therapy for hereditary retinal diseases, a phase 3 clinical trial of voretigene neparvovec (AAV2-hRPE65v2, Luxturna) recently showed significant efficacy for RPE65-mediated inherited retinal dystrophy including Leber congenital amaurosis and RP. It is about to be approved as the first ocular gene therapy biologic product. Despite current limitations such as limited target genes and indicated patients, modest efficacy, and the invasive administration method, development in gene editing technology and novel gene delivery carriers make gene therapy a promising therapeutic modality for RP and other hereditary retinal dystrophies in the future.
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Affiliation(s)
- Marina França Dias
- School of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil; Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Jessica A Kemp
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | - Silvia Ligório Fialho
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Brazil
| | | | - Se Joon Woo
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA; Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
| | - Young Jik Kwon
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA; Department of Chemical Engineering and Materials Sciences, University of California, Irvine, CA, USA; Department of Biomedical Engineering, University of California, Irvine, CA, USA; Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
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Hanlon KS, Chadderton N, Palfi A, Blanco Fernandez A, Humphries P, Kenna PF, Millington-Ward S, Farrar GJ. A Novel Retinal Ganglion Cell Promoter for Utility in AAV Vectors. Front Neurosci 2017; 11:521. [PMID: 28983234 PMCID: PMC5613148 DOI: 10.3389/fnins.2017.00521] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 09/04/2017] [Indexed: 12/13/2022] Open
Abstract
Significant advances in gene therapy have enabled exploration of therapies for inherited retinal disorders, many of which are in preclinical development or clinical evaluation. Gene therapy for retinal conditions has led the way in this growing field. The loss of retinal ganglion cells (RGCs) is a hallmark of a number of retinal disorders. As the field matures innovations that aid in refining therapies and optimizing efficacy are in demand. Gene therapies under development for RGC-related disorders, when delivered with recombinant adeno associated vectors (AAV), have typically been expressed from ubiquitous promoter sequences. Here we describe how a novel promoter from the murine Nefh gene was selected to drive transgene expression in RGCs. The Nefh promoter, in an AAV2/2 vector, was shown to drive preferential EGFP expression in murine RGCs in vivo following intravitreal injection. In contrast, EGFP expression from a CMV promoter was observed not only in RGCs, but throughout the inner nuclear layer and in amacrine cells located within the ganglion cell layer (GCL). Of note, the Nefh promoter sequence is sufficiently compact to be readily accommodated in AAV vectors, where transgene size represents a significant constraint. Moreover, this promoter should in principle provide a more targeted and potentially safer alternative for RGC-directed gene therapies.
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Affiliation(s)
- Killian S Hanlon
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Naomi Chadderton
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Arpad Palfi
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | | | - Peter Humphries
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - Paul F Kenna
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland.,Research Foundation, Royal Victoria Eye and Ear HospitalDublin, Ireland
| | - Sophia Millington-Ward
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
| | - G Jane Farrar
- School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College DublinDublin, Ireland
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Affiliation(s)
- Arthur Planul
- Inserm, Institut de la Vision, UMR S968, 75012 Paris, France;,
- Sorbonne Universités, UPMC Université Paris 6, UMR S968, 75012 Paris, France
- CNRS, UMR 7210, 75012 Paris, France
| | - Deniz Dalkara
- Inserm, Institut de la Vision, UMR S968, 75012 Paris, France;,
- Sorbonne Universités, UPMC Université Paris 6, UMR S968, 75012 Paris, France
- CNRS, UMR 7210, 75012 Paris, France
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36
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Heier JS, Kherani S, Desai S, Dugel P, Kaushal S, Cheng SH, Delacono C, Purvis A, Richards S, Le-Halpere A, Connelly J, Wadsworth SC, Varona R, Buggage R, Scaria A, Campochiaro PA. Intravitreous injection of AAV2-sFLT01 in patients with advanced neovascular age-related macular degeneration: a phase 1, open-label trial. Lancet 2017; 390:50-61. [PMID: 28526489 DOI: 10.1016/s0140-6736(17)30979-0] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Long-term intraocular injections of vascular endothelial growth factor (VEGF)-neutralising proteins can preserve central vision in many patients with neovascular age-related macular degeneration. We tested the safety and tolerability of a single intravitreous injection of an AAV2 vector expressing the VEGF-neutralising protein sFLT01 in patients with advanced neovascular age-related macular degeneration. METHODS This was a phase 1, open-label, dose-escalating study done at four outpatient retina clinics in the USA. Patients were assigned to each cohort in order of enrolment, with the first three patients being assigned to and completing the first cohort before filling positions in the following treatment groups. Patients aged 50 years or older with neovascular age-related macular degeneration and a baseline best-corrected visual acuity score of 20/100 or less in the study eye were enrolled in four dose-ranging cohorts (cohort 1, 2 × 108 vector genomes (vg); cohort 2, 2 × 109 vg; cohort 3, 6 × 109 vg; and cohort 4, 2 × 1010 vg, n=3 per cohort) and one maximum tolerated dose cohort (cohort 5, 2 × 1010 vg, n=7) and followed up for 52 weeks. The primary objective of the study was to assess the safety and tolerability of a single intravitreous injection of AAV2-sFLT01, through the measurement of eye-related adverse events. This trial is registered with ClinicalTrials.gov, number NCT01024998. FINDINGS 19 patients with advanced neovascular age-related macular degeneration were enrolled in the study between May 18, 2010, and July 14, 2014. All patients completed the 52-week trial period. Two patients in cohort 4 (2 × 1010 vg) experienced adverse events that were possibly study-drug related: pyrexia and intraocular inflammation that resolved with a topical steroid. Five of ten patients who received 2 × 1010 vg had aqueous humour concentrations of sFLT01 that peaked at 32·7-112·0 ng/mL (mean 73·7 ng/mL, SD 30·5) by week 26 with a slight decrease to a mean of 53·2 ng/mL at week 52 (SD 17·1). At baseline, four of these five patients were negative for anti-AAV2 serum antibodies and the fifth had a very low titre (1:100) of anti-AAV2 antibodies, whereas four of the five non-expressers of sFLT01 had titres of 1:400 or greater. In 11 of 19 patients with intraretinal or subretinal fluid at baseline judged to be reversible, six showed substantial fluid reduction and improvement in vision, whereas five showed no fluid reduction. One patient in cohort 5 showed a large decrease in vision between weeks 26 and 52 that was not thought to be vector-related. INTERPRETATION Intravitreous injection of AAV2-sFLT01 seemed to be safe and well tolerated at all doses. Additional studies are needed to identify sources of variability in expression and anti-permeability activity, including the potential effect of baseline anti-AAV2 serum antibodies. FUNDING Sanofi Genzyme, Framingham, MA, USA.
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Affiliation(s)
| | - Saleema Kherani
- Departments of Ophthalmology and Neuroscience, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore MD, USA
| | - Shilpa Desai
- Ophthalmic Consultants of Boston, Boston, MA, USA
| | - Pravin Dugel
- Retinal Consultants of Arizona, Phoenix, AZ, USA
| | - Shalesh Kaushal
- University of Massachusetts Medical Center, Worcester, MA, USA
| | | | | | | | | | | | | | | | | | | | | | - Peter A Campochiaro
- Departments of Ophthalmology and Neuroscience, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore MD, USA.
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Tshilenge KT, Ameline B, Weber M, Mendes-Madeira A, Nedellec S, Biget M, Provost N, Libeau L, Blouin V, Deschamps JY, Le Meur G, Colle MA, Moullier P, Pichard V, Rolling F. Vitrectomy Before Intravitreal Injection of AAV2/2 Vector Promotes Efficient Transduction of Retinal Ganglion Cells in Dogs and Nonhuman Primates. Hum Gene Ther Methods 2017; 27:122-34. [PMID: 27229628 DOI: 10.1089/hgtb.2016.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Recombinant adeno-associated virus (AAV) has emerged as a promising vector for retinal gene delivery to restore visual function in certain forms of inherited retinal dystrophies. Several studies in rodent models have shown that intravitreal injection of the AAV2/2 vector is the optimal route for efficient retinal ganglion cell (RGC) transduction. However, translation of these findings to larger species, including humans, is complicated by anatomical differences in the eye, a key difference being the comparatively smaller volume of the vitreous chamber in rodents. Here, we address the role of the vitreous body as a potential barrier to AAV2/2 diffusion and transduction in the RGCs of dogs and macaques, two of the most relevant preclinical models. We intravitreally administered the AAV2/2 vector carrying the CMV-eGFP reporter cassette in dog and macaque eyes, either directly into the vitreous chamber or after complete vitrectomy, a surgical procedure that removes the vitreous body. Our findings suggest that the vitreous body appears to trap the injected vector, thus impairing the diffusion and transduction of AAV2/2 to inner retinal neurons. We show that vitrectomy before intravitreal vector injection is an effective means of overcoming this physical barrier, improving the transduction of RGCs in dog and macaque retinas. These findings support the use of vitrectomy in clinical trials of intravitreal gene transfer techniques targeting inner retinal neurons.
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Affiliation(s)
| | - Baptiste Ameline
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
| | - Michel Weber
- 2 CHU de Nantes, Service d'Ophtalmologie, Nantes, France
| | | | - Steven Nedellec
- 3 Cellular and Tissular Imaging Core Facility of Nantes University, SFR Santé Francois Bonamy INSERM UMS016/CNRS UMS3556, Nantes, France
| | - Marine Biget
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
| | - Nathalie Provost
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
| | - Lyse Libeau
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
| | - Véronique Blouin
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
| | - Jack-Yves Deschamps
- 4 Emergency and Critical Care Unit, ONIRIS, Nantes-Atlantic College of Veterinary Medicine Food Science and Engineering, Nantes, France
| | | | - Marie-Anne Colle
- 5 UMR 703 PAnTher INRA/ONIRIS, Nantes-Atlantic College of Veterinary Medicine Food Science and Engineering, Nantes, France
| | - Philippe Moullier
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France.,6 Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida , Gainesville, Florida
| | - Virginie Pichard
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
| | - Fabienne Rolling
- 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
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Cideciyan AV, Roman AJ, Jacobson SG, Yan B, Pascolini M, Charng J, Pajaro S, Nirenberg S. Developing an Outcome Measure With High Luminance for Optogenetics Treatment of Severe Retinal Degenerations and for Gene Therapy of Cone Diseases. Invest Ophthalmol Vis Sci 2017; 57:3211-21. [PMID: 27309625 PMCID: PMC4928698 DOI: 10.1167/iovs.16-19586] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To present stimuli with varied sizes, colors, and patterns over a large range of luminance. Methods The filter bar used in scotopic MP1 was replaced with a custom slide-in tray that introduces light from an external projector driven by an additional computer. MP1 software was modified to provide retinal tracking information to the computer driving the projector. Retinal tracking performance was evaluated by imaging the system input and the output simultaneously with a high-speed video system. Spatial resolution was measured with achromatic and chromatic grating/background combinations over scotopic and photopic ranges. Results The range of retinal illuminance achievable by the modification was up to 6.8 log photopic Trolands (phot-Td); however, in the current work, only a lower range over −4 to +3 log phot-Td was tested in human subjects. Optical magnification was optimized for low-vision testing with gratings from 4.5 to 0.2 cyc/deg. In normal subjects, spatial resolution driven by rods, short wavelength-sensitive (S-) cones, and long/middle wavelength-sensitive (L/M-) cones was obtained by the choice of adapting conditions and wavelengths of grating and background. Data from a patient with blue cone monochromacy was used to confirm mediation. Conclusions The modified MP1 can be developed into an outcome measure for treatments in patients with severe retinal degeneration, very low vision, and abnormal eye movements such as those for whom treatment with optogenetics is planned, as well as for patients with cone disorders such as blue cone monochromacy for whom treatment with gene therapy is planned to improve L/M-cone function above a normal complement of rod and S-cone function.
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Affiliation(s)
- Artur V Cideciyan
- Scheie Eye Institute Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alejandro J Roman
- Scheie Eye Institute Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Samuel G Jacobson
- Scheie Eye Institute Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Boyuan Yan
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States
| | | | - Jason Charng
- Scheie Eye Institute Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | | | - Sheila Nirenberg
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States
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Wang W, Nan Y, Pan ZH, Pu M. Morphological evaluation of retinal ganglion cells expressing the L132C/T159C ChR2 mutant transgene in young adult cynomolgus monkeys. SCIENCE CHINA-LIFE SCIENCES 2017; 60:1157-1167. [PMID: 28550523 DOI: 10.1007/s11427-017-9055-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/03/2017] [Indexed: 11/24/2022]
Abstract
To characterize recombinant AAV2 (rAAV2)-mediated expression of L132C/T159C ChR2 mutant in retinal ganglion cells (RGCs) of young adult cynomolgus monkeys. rAAV2 vectors carrying a fusion construct of the ChR2 mutant and GFP (ChR2-GFP) were delivered to the vitreous chamber by intravitreal injection. Expression patterns of the ChR2 mutant in RGCs were examined by immunohistochemical methods three months after injection. The RNA-binding protein with multiple splicing (RBPMS) was used as an RGC specific marker to differentiate RGCs from other retinal neurons and non-neuronal cells. The numbers of RBPMS+ and GFP+ double-labeled RGCs in the central foveal varied with the eccentricity. The expression peaked within 100 μm from the edge of the foveola and drastically decreased to a single superficial RGC layer approximately 300 μm from the edge. On average, the ratio of the double-labeled RGCs versus RBPMS+ RGCs approached 0.32±0.15 (n=14 fields) at the central foveal region (0.1 to 0.53 mm). We observed that the ratio reached 0.78±0.16 (n=21 fields) at peripheral retinal locations (eccentricity >7 mm). This investigation demonstrates that RBPMS could serve as a valuable RGC specific marker for future investigations in this field.
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Affiliation(s)
- Wenyao Wang
- Department of Embryology/Anatomy, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Yan Nan
- Department of Embryology/Anatomy, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Zhuo-Hua Pan
- Department of Ophthalmology and Anatomy/Cell Biology, Wayne State University School of Medicine, Detroit Michigan, 48201, USA.
| | - Mingliang Pu
- Department of Embryology/Anatomy, School of Basic Medical Sciences, Peking University, Beijing, 100191, China.
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Korbmacher B, Atorf J, Fridrichs-Gromoll S, Hill M, Korte S, Kremers J, Mansfield K, Mecklenburg L, Pilling A, Wiederhold A. Feasibility of intravitreal injections and ophthalmic safety assessment in marmoset ( Callithrix jacchus) monkeys. Primate Biol 2017; 4:93-100. [PMID: 32110696 PMCID: PMC7041524 DOI: 10.5194/pb-4-93-2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 04/04/2017] [Indexed: 11/15/2022] Open
Abstract
To
safeguard patients, regulatory authorities require that new drugs that are to be given
by the intravitreal (IVT) route are assessed for their safety in a laboratory
species using the same route of administration. Due to the high
similarity of ocular morphology and physiology between humans and nonhuman
primates (NHPs) and due to the species specificity of many biotherapeutics,
the monkey is often the only appropriate model. To this end, intravitreal
administration and assessment of ocular toxicity are well established in
cynomolgus monkeys (Macaca fascicularis). In contrast, the common
marmoset monkey (Callithrix jacchus) is not a standard model for
ocular toxicity studies due to its general sensitivity to laboratory
investigations and small eye size. It was the purpose of the present work to
study whether the marmoset is a useful alternative to the cynomolgus monkey
for use in intravitreal toxicological studies. Six marmoset monkeys received
repeated (every 2 weeks for a total of four doses) intravitreal injections of
10 or 20 µL of a placebo. The animals were assessed for
measurements of intraocular pressure (IOP), standard ophthalmological
investigations and electroretinography (ERG). At the end of the dosing
period, the animals were sacrificed and the eyes were evaluated
histologically. ERG revealed similar results when comparing predose to
end-of-study data, and there was no difference between the two dose volumes.
A transient increase in the IOP was seen immediately after dosing, which was
more pronounced after dosing of 20 µL compared to 10 µL.
Ophthalmologic and microscopic observations did not show any significant
changes. Therefore, it can be concluded that 10 µL as well as
20 µL intravitreal injections of a placebo are well tolerated in
the marmoset. These results demonstrate that the common marmoset is an
alternative to the cynomolgus monkey for intravitreal toxicity testing.
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Affiliation(s)
- Birgit Korbmacher
- Covance Preclinical Services GmbH, Kesselfeld 29, 48163 Münster, Germany
| | - Jenny Atorf
- Department of Ophthalmology, University Hospital Erlangen, Maximiliansplatz 2, 91054 Erlangen, Germany
| | | | - Marilyn Hill
- Novartis Pharma AG, Basel, Klybeckstraße, 4002 Basel, Switzerland
| | - Sven Korte
- Covance Preclinical Services GmbH, Kesselfeld 29, 48163 Münster, Germany
| | - Jan Kremers
- Department of Ophthalmology, University Hospital Erlangen, Maximiliansplatz 2, 91054 Erlangen, Germany
| | - Keith Mansfield
- Novartis Pharma AG, Basel, Klybeckstraße, 4002 Basel, Switzerland
| | - Lars Mecklenburg
- Covance Preclinical Services GmbH, Kesselfeld 29, 48163 Münster, Germany
| | - Andrew Pilling
- Novartis Pharma AG, Basel, Klybeckstraße, 4002 Basel, Switzerland
| | - Andreas Wiederhold
- Covance Preclinical Services GmbH, Kesselfeld 29, 48163 Münster, Germany
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41
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Cheng DL, Greenberg PB, Borton DA. Advances in Retinal Prosthetic Research: A Systematic Review of Engineering and Clinical Characteristics of Current Prosthetic Initiatives. Curr Eye Res 2017; 42:334-347. [PMID: 28362177 DOI: 10.1080/02713683.2016.1270326] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE To date, reviews of retinal prostheses have focused primarily on devices undergoing human trials in the Western Hemisphere and fail to capture significant advances in materials and engineering research in countries such as Japan and Korea, as well as projects in early stages of development. To address these gaps, this systematic review examines worldwide advances in retinal prosthetic research, evaluates engineering characteristics and clinical progress of contemporary device initiatives, and identifies potential directions for future research in the field of retinal prosthetics. METHODS A literature search using PubMed, Google Scholar, and IEEExplore was conducted following the PRISMA Guidelines for Systematic Review. Inclusion criteria were peer-reviewed papers demonstrating progress in human or animal trials and papers discussing the prosthetic engineering design. For each initiative, a description of the device, its engineering considerations, and recent clinical results were provided. RESULTS Ten prosthetic initiatives met our inclusion criteria and were organized by stimulation location. Of these initiatives, four have recently completed human trials, three are undergoing multi- or single-center human trials, and three are undergoing preclinical animal testing. Only the Argus II (FDA 2013, CE 2011) has obtained FDA approval for use in the United States; the Alpha-IMS (CE 2013) has achieved the highest visual acuity using a Landolt-C test to date and is the only device presently undergoing a multicenter clinical trial. CONCLUSION Several distinct approaches to retinal stimulation have been successful in eliciting visual precepts in animals and/or humans. However, many clinical needs are still not met and engineering challenges must be addressed before a retinal prosthesis with the capability to fully and safely restore functional vision can be realized.
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Affiliation(s)
- Derrick L Cheng
- a Alpert Medical School , Brown University , Providence , RI , USA
| | - Paul B Greenberg
- b Section of Ophthalmology , Providence VA Medical Center , Providence , RI , USA.,c Division of Ophthalmology, Alpert Medical School , Brown University , Providence , RI , USA
| | - David A Borton
- d School of Engineering , Brown University , Providence , RI , USA.,e Brown Institute for Brain Science , Brown University , Providence , RI , USA
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42
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Masri RA, Percival KA, Koizumi A, Martin PR, Grünert U. Survey of retinal ganglion cell morphology in marmoset. J Comp Neurol 2017; 527:236-258. [PMID: 27997691 DOI: 10.1002/cne.24157] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 11/09/2016] [Accepted: 11/09/2016] [Indexed: 01/05/2023]
Abstract
In primate retina, the midget, parasol, and small bistratified cell populations form the large majority of ganglion cells. In addition, there is a variety of low-density wide-field ganglion cell types that are less well characterized. Here we studied retinal ganglion cells in the common marmoset, Callithrix jacchus, using particle-mediated gene transfer. Ganglion cells were transfected with an expression plasmid for the postsynaptic density 95-green fluorescent protein. The retinas were processed with established immunohistochemical markers for bipolar and/or amacrine cells to determine ganglion cell dendritic stratification. In total over 500 ganglion cells were classified based on their dendritic field size, morphology, and stratification in the inner plexiform layer. Over 17 types were distinguished, including midget, parasol, broad thorny, small bistratified, large bistratified, recursive bistratified, recursive monostratified, narrow thorny, smooth monostratified, large sparse, giant sparse (melanopsin) ganglion cells, and a group that may contain several as yet uncharacterized types. Assuming each characterized type forms a hexagonal mosaic, the midget and parasol cells account for over 80% of all ganglion cells in the central retina but only ∼50% of cells in the peripheral (>2 mm) retina. We conclude that the fovea is dominated by midget and parasol cells, but outside the fovea the ganglion cell diversity in marmoset is likely as great as that reported for nonprimate retinas. Taken together, the ganglion cell types in marmoset retina resemble those described previously in macaque retina with respect to morphology, stratification, and change in proportion across the retina.
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Affiliation(s)
- Rania A Masri
- Save Sight Institute and Department of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales, Australia
| | - Kumiko A Percival
- Save Sight Institute and Department of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales, Australia
| | - Amane Koizumi
- National Institutes of Natural Sciences, Tokyo, Japan
| | - Paul R Martin
- Save Sight Institute and Department of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, Australia.,School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Ulrike Grünert
- Save Sight Institute and Department of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, Australia.,School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
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43
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Correction of Monogenic and Common Retinal Disorders with Gene Therapy. Genes (Basel) 2017; 8:genes8020053. [PMID: 28134823 PMCID: PMC5333042 DOI: 10.3390/genes8020053] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/19/2017] [Indexed: 11/16/2022] Open
Abstract
The past decade has seen major advances in gene-based therapies, many of which show promise for translation to human disease. At the forefront of research in this field is ocular disease, as the eye lends itself to gene-based interventions due to its accessibility, relatively immune-privileged status, and ability to be non-invasively monitored. A landmark study in 2001 demonstrating successful gene therapy in a large-animal model for Leber congenital amaurosis set the stage for translation of these strategies from the bench to the bedside. Multiple clinical trials have since initiated for various retinal diseases, and further improvements in gene therapy techniques have engendered optimism for alleviating inherited blinding disorders. This article provides an overview of gene-based strategies for retinal disease, current clinical trials that engage these strategies, and the latest techniques in genome engineering, which could serve as the next frontline of therapeutic interventions.
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44
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Heparan Sulfate Binding Promotes Accumulation of Intravitreally Delivered Adeno-associated Viral Vectors at the Retina for Enhanced Transduction but Weakly Influences Tropism. J Virol 2016; 90:9878-9888. [PMID: 27558418 DOI: 10.1128/jvi.01568-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 08/15/2016] [Indexed: 12/20/2022] Open
Abstract
Many adeno-associated virus (AAV) serotypes efficiently transduce the retina when delivered to the subretinal space but show limited success when delivered to the vitreous due to the inner limiting membrane (ILM). Subretinal delivery of AAV serotype 2 (AAV2) and its heparan sulfate (HS)-binding-deficient capsid led to similar expression, indicating transduction of the outer retina occurred by HS-independent mechanisms. However, intravitreal delivery of HS-ablated recombinant AAV2 (rAAV2) led to a 300-fold decrease in transduction compared to AAV2. Fluorescence in situ hybridization of AAV transgenes was used to identify differences in retinal trafficking and revealed that HS binding was responsible for AAV2 accumulation at the ILM. This mechanism was tested on human ex vivo retinas and showed similar accumulation with HS-binding AAV2 capsid only. To evaluate if HS binding could be applied to other AAV serotypes to enhance their transduction, AAV1 and AAV8 were modified to bind HS with a single-amino-acid mutation and tested in mice. Both HS-binding mutants of AAV1 and AAV8 had higher intravitreal transduction than their non-HS-binding parent capsid due to increased retinal accumulation. To understand the influence that HS binding has on tropism, chimeric AAV2 capsids with dual-glycan usage were tested intravitreally in mice. Compared to HS binding alone, these chimeric capsids displayed enhanced transduction that was correlated with a change in tropism. Taken together, these data indicate that HS binding serves to sequester AAV capsids from the vitreous to the ILM but does not influence retinal tropism. The enhanced retinal transduction of HS-binding capsids provides a rational design strategy for engineering capsids for intravitreal delivery. IMPORTANCE Adeno-associated virus (AAV) has become the vector of choice for viral gene transfer and has shown great promise in clinical trials. The need for development of an easy, less invasive injection route for ocular gene therapy is met by intravitreal delivery, but delivery of AAV by this route results in poor transduction outcomes. The inner limiting membrane (ILM) creates a barrier separating the vitreous and the retina. Binding of AAV to heparan sulfate proteoglycan (HSPG) at the ILM may allow the virus to traverse this barrier for better retinal transduction. We show that HSPG binding is correlated with greater accumulation and penetration of AAV in the retina. We demonstrated that this accumulation is conserved across mouse and human retinas and that the addition of HSPG binding to other AAV capsids can increase the number of vectors accumulating at the ILM without dictating tropism.
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Klapper SD, Swiersy A, Bamberg E, Busskamp V. Biophysical Properties of Optogenetic Tools and Their Application for Vision Restoration Approaches. Front Syst Neurosci 2016; 10:74. [PMID: 27642278 PMCID: PMC5009148 DOI: 10.3389/fnsys.2016.00074] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/17/2016] [Indexed: 11/13/2022] Open
Abstract
Optogenetics is the use of genetically encoded light-activated proteins to manipulate cells in a minimally invasive way using light. The most prominent example is channelrhodopsin-2 (ChR2), which allows the activation of electrically excitable cells via light-dependent depolarization. The combination of ChR2 with hyperpolarizing-light-driven ion pumps such as the Cl(-) pump halorhodopsin (NpHR) enables multimodal remote control of neuronal cells in culture, tissue, and living animals. Very soon, it became obvious that this method offers a chance of gene therapy for many diseases affecting vision. Here, we will give a brief introduction to retinal function and retinal diseases; optogenetic vision restoration strategies will be highlighted. We will discuss the functional and structural properties of rhodopsin-based optogenetic tools and analyze the potential for the application of vision restoration.
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Affiliation(s)
- Simon D Klapper
- Center for Regenerative Therapies Dresden, Technische Universität Dresden Dresden, Germany
| | - Anka Swiersy
- Center for Regenerative Therapies Dresden, Technische Universität Dresden Dresden, Germany
| | - Ernst Bamberg
- Max Planck Institute of Biophysics Frankfurt, Germany
| | - Volker Busskamp
- Center for Regenerative Therapies Dresden, Technische Universität Dresden Dresden, Germany
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Lu Q, Ganjawala TH, Ivanova E, Cheng JG, Troilo D, Pan ZH. AAV-mediated transduction and targeting of retinal bipolar cells with improved mGluR6 promoters in rodents and primates. Gene Ther 2016; 23:680-9. [PMID: 27115727 PMCID: PMC4863234 DOI: 10.1038/gt.2016.42] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 04/14/2016] [Accepted: 04/18/2016] [Indexed: 12/20/2022]
Abstract
Adeno-associated virus (AAV) vectors have been a powerful gene delivery vehicle to the retina for basic research and gene therapy. For many of these applications, achieving cell type-specific targeting and high transduction efficiency is desired. Recently, there has been increasing interest in AAV-mediated gene targeting to specific retinal bipolar cell types. A 200-bp enhancer in combination with a basal SV40 promoter has been commonly used to target transgenes into ON-type bipolar cells. In the current study, we searched for additional cis-regulatory elements in the mGluR6 gene for improving AAV-mediated transduction efficiency into retinal bipolar cells. Our results showed that the combination of the endogenous mGluR6 promoter with additional enhancers in the introns of the mGluR6 gene markedly enhanced AAV transduction efficiency as well as made the targeting more selective for rod bipolar cells in mice. Furthermore, the AAV vectors with the improved promoter could target to ON bipolar cells with robust transduction efficiency in the parafovea and the far peripheral retina of marmoset monkeys. The improved mGluR6 promoter constructs could provide a valuable tool for genetic manipulation in rod bipolar cells in mice and facilitate clinical applications for ON bipolar cell-based gene therapies.
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Affiliation(s)
- Q Lu
- Dept. of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI
| | - TH Ganjawala
- Dept. of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI
| | - E Ivanova
- Burke Medical Research Institute, Weill Medical College of Cornell University, White Plains, NY
| | - JG Cheng
- Neuroscience Center, University of North Carolina, Chapel Hill, NC
| | - D Troilo
- State University of New York, College of Optometry, New York, NY
| | - Z-H Pan
- Dept. of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI
- Dept. of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI
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47
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Yue L, Weiland JD, Roska B, Humayun MS. Retinal stimulation strategies to restore vision: Fundamentals and systems. Prog Retin Eye Res 2016; 53:21-47. [DOI: 10.1016/j.preteyeres.2016.05.002] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/13/2016] [Accepted: 05/21/2016] [Indexed: 11/28/2022]
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48
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Boyd RF, Sledge DG, Boye SL, Boye SE, Hauswirth WW, Komáromy AM, Petersen-Jones SM, Bartoe JT. Photoreceptor-targeted gene delivery using intravitreally administered AAV vectors in dogs. Gene Ther 2016; 23:223-30. [PMID: 26467396 PMCID: PMC4840844 DOI: 10.1038/gt.2015.96] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/03/2015] [Accepted: 08/24/2015] [Indexed: 12/11/2022]
Abstract
Delivery of therapeutic transgenes to retinal photoreceptors using adeno-associated virus (AAV) vectors has traditionally required subretinal injection. Recently, photoreceptor transduction efficiency following intravitreal injection (IVT) has improved in rodent models through use of capsid-mutant AAV vectors; but remains limited in large animal models. Thickness of the inner limiting membrane (ILM) in large animals is thought to impair retinal penetration by AAV. Our study compared two newly developed AAV vectors containing multiple capsid amino acid substitutions following IVT in dogs. The ability of two promoter constructs to restrict reporter transgene expression to photoreceptors was also evaluated. AAV vectors containing the interphotoreceptor-binding protein (IRBP) promoter drove expression exclusively in rod and cone photoreceptors, with transduction efficiencies of ~4% of cones and 2% of rods. Notably, in the central region containing the cone-rich visual streak, 15.6% of cones were transduced. Significant regional variation existed, with lower transduction efficiencies in the temporal regions of all eyes. This variation did not correlate with ILM thickness. Vectors carrying a cone-specific promoter failed to transduce a quantifiable percentage of cone photoreceptors. The newly developed AAV vectors containing the IRBP promoter were capable of producing photoreceptor-specific transgene expression following IVT in the dog.
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Affiliation(s)
- RF Boyd
- Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - DG Sledge
- Diagnostic Center for Population and Animal Health, Michigan State University, East Lansing, MI, USA
| | - SL Boye
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - SE Boye
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - WW Hauswirth
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - AM Komáromy
- Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - SM Petersen-Jones
- Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - JT Bartoe
- Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
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49
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Abstract
Severe loss of photoreceptor cells in inherited or acquired retinal degenerative diseases can result in partial loss of sight or complete blindness. The optogenetic strategy for restoration of vision utilizes optogenetic tools to convert surviving inner retinal neurons into photosensitive cells; thus, light sensitivity is imparted to the retina after the death of photoreceptor cells. Proof-of-concept studies, especially those using microbial rhodopsins, have demonstrated restoration of light responses in surviving retinal neurons and visually guided behaviors in animal models. Significant progress has also been made in improving microbial rhodopsin-based optogenetic tools, developing virus-mediated gene delivery, and targeting specific retinal neurons and subcellular compartments of retinal ganglion cells. In this article, we review the current status of the field and outline further directions and challenges to the advancement of this strategy toward clinical application and improvement in the outcomes of restored vision.
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Affiliation(s)
- Zhuo-Hua Pan
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan 48201; , , .,Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201;
| | - Qi Lu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201;
| | - Anding Bi
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan 48201; , ,
| | | | - Gary W Abrams
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan 48201; , ,
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Masri RA, Percival KA, Koizumi A, Martin PR, Grünert U. Connectivity between the OFF bipolar type DB3a and six types of ganglion cell in the marmoset retina. J Comp Neurol 2015; 524:1839-58. [PMID: 26559914 DOI: 10.1002/cne.23925] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/12/2015] [Accepted: 11/09/2015] [Indexed: 12/31/2022]
Abstract
Parallel visual pathways originate at the first synapse in the retina, where cones make connections with cone bipolar cells that in turn contact ganglion cells. There are more ganglion cell types than bipolar types, suggesting that there must be divergence from bipolar to ganglion cells. Here we analyze the contacts between an OFF bipolar type (DB3a) and six ganglion cell types in the retina of the marmoset monkey (Callithrix jacchus). Ganglion cells were transfected via particle-mediated gene transfer of an expression plasmid for the postsynaptic density 95-green fluorescent protein (PSD95-GFP), and DB3a cells were labeled via immunohistochemistry. Ganglion cell types that fully or partially costratified with DB3a cells included OFF parasol, OFF midget, broad thorny, recursive bistratified, small bistratified, and large bistratified cells. On average, the number of DB3a contacts to parasol cells (18 contacts per axon terminal) is higher than that to other ganglion cell types (between four and seven contacts). We estimate that the DB3a output to OFF parasol cells accounts for at least 30% of the total DB3a output. Furthermore, we found that OFF parasol cells receive approximately 20% of their total bipolar input from DB3a cells, suggesting that other diffuse bipolar types also provide input to OFF parasol cells. We conclude that DB3a cells preferentially contact OFF parasol cells but also provide input to other ganglion cell types.
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Affiliation(s)
- Rania A Masri
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia
| | - Kumiko A Percival
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia
| | - Amane Koizumi
- National Institutes of Natural Sciences, Tokyo, Japan
| | - Paul R Martin
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, 2000, Australia.,School of Medical Sciences, The University of Sydney, Sydney, New South Wales, 2000, Australia
| | - Ulrike Grünert
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, 2000, Australia.,School of Medical Sciences, The University of Sydney, Sydney, New South Wales, 2000, Australia
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