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Busskamp V, Roska B, Sahel JA. Optogenetic Vision Restoration. Cold Spring Harb Perspect Med 2024; 14:a041660. [PMID: 37734866 PMCID: PMC11293536 DOI: 10.1101/cshperspect.a041660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Optogenetics has emerged over the past 20 years as a powerful tool to investigate the various circuits underlying numerous functions, especially in neuroscience. The ability to control by light the activity of neurons has enabled the development of therapeutic strategies aimed at restoring some level of vision in blinding retinal conditions. Promising preclinical and initial clinical data support such expectations. Numerous challenges remain to be tackled (e.g., confirmation of safety, cell and circuit specificity, patterns, intensity and mode of stimulation, rehabilitation programs) on the path toward useful vision restoration.
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Affiliation(s)
- Volker Busskamp
- Degenerative Retinal Diseases, University Hospital Bonn, 53127 Bonn, Germany
| | - Botond Roska
- Institute of Molecular and Clinical Ophthalmology Basel, 4031 Basel, Switzerland
- Department of Ophthalmology, University of Basel, 4001 Basel, Switzerland
| | - Jose-Alain Sahel
- Department of Ophthalmology, UPMC Vision Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
- Institut Hospitalo-Universitaire FOReSIGHT, Sorbonne Universite, Inserm, Quinze-Vingts Hopital de la Vision, 75012 Paris, France
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2
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Araujo VG, Dias MS, Hauswirth WW, Linden R, Petrs-Silva H. rAAV-compatible human mini promoters enhance transgene expression in rat retinal ganglion cells. Exp Eye Res 2024; 239:109758. [PMID: 38123011 DOI: 10.1016/j.exer.2023.109758] [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: 08/02/2023] [Revised: 11/14/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023]
Abstract
Recombinant adeno-associated viral vectors (rAAV) are the safest and most effective gene delivery platform to drive the treatment of many inherited eye disorders in well-characterized animal models. The use in rAAV of ubiquitous promoters derived from viral sequences such as CMV/CBA (chicken β-actin promoter with cytomegalovirus enhancer) can lead to unwanted side effects such as pro-inflammatory immune responses and retinal cytotoxicity, thus reducing therapy efficacy. Thus, an advance in gene therapy is the availability of small promoters, that potentiate and direct gene expression to the cell type of interest, with higher safety and efficacy. In this study, we used six human mini-promoters packaged in rAAV2 quadruple mutant (Y-F) to test for transduction of the rat retina after intravitreal injection. After four weeks, immunohistochemical analysis detected GFP-labeled cells in the ganglion cell layer (GCL) for all constructs tested. Among them, Ple25sh1, Ple25sh2 and Ple53 promoted a widespread reporter-transgene expression in the GCL, with an increased number of GFP-expressing retinal ganglion cells when compared with the CMV/CBA vector. Moreover, Ple53 provided the strongest levels of GFP fluorescence in both cell soma and axons of retinal ganglion cells (RGCs) without any detectable adverse effects in retina function. Remarkably, a nearly 50-fold reduction in the number of intravitreally injected vector particles containing Ple53 promoter, still attained levels of transgene expression similar to CMV/CBA. Thus, the tested MiniPs show great potential for protocols of retinal gene therapy in therapeutic applications for retinal degenerations, especially those involving RGC-related disorders such as glaucoma.
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Affiliation(s)
- Victor G Araujo
- Laboratory of Gene Therapy and Viral Vector, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mariana S Dias
- Laboratory of Gene Therapy and Viral Vector, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - William W Hauswirth
- Retinal Gene Therapy Group, Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Rafael Linden
- Laboratory of Neurogenesis, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Hilda Petrs-Silva
- Laboratory of Gene Therapy and Viral Vector, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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3
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Takahashi K, Kwok JC, Sato Y, Aguirre GD, Miyadera K. Extended functional rescue following AAV gene therapy in a canine model of LRIT3-congenital stationary night blindness. Vision Res 2023; 209:108260. [PMID: 37220680 PMCID: PMC10524691 DOI: 10.1016/j.visres.2023.108260] [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: 12/19/2022] [Revised: 04/21/2023] [Accepted: 04/21/2023] [Indexed: 05/25/2023]
Abstract
Congenital stationary night blindness (CSNB) is a group of inherited retinal diseases in which either rod-to-ON-bipolar cell (ON-BC) signaling, or rod function is affected leading to impaired vision under low light conditions. One type of CSNB is associated with defects in genes (NYX, GRM6, TRPM1, GPR179, and LRIT3) involved in the mGluR6 signaling cascade at the ON-BC dendritic tips. We have previously characterized a canine model of LRIT3-CSNB and demonstrated short-term safety and efficacy of an ON-BC targeting AAV-LRIT3 (AAVK9#4-shGRM6-cLRIT3-WPRE) gene therapy. Herein, we demonstrate long-term functional recovery and molecular restoration following subretinal injection of the ON-BC targeting AAV-LRIT3 vector in all eight treated eyes for up to 32 months. Following subretinal administration of the therapeutic vector, expression of the LRIT3 transgene, as well as restoration of mGluR6 signaling cascade member TRPM1, were confirmed in the outer plexiform layer (OPL) of the treated area. However, further investigation of the transgene LRIT3 transcript expression by RNA in situ hybridization (RNA-ISH) revealed off-target expression in non-BCs including the photoreceptors, inner nuclear, and ganglion cell layers, despite the use of a mutant AAVK9#4 capsid and an improved mGluR6 promoter designed to specifically transduce and promote expression in ON-BCs. While the long-term therapeutic potential of AAVK9#4-shGRM6-cLRIT3-WPRE is promising, we highlight the necessity for further optimization of AAV-LRIT3 therapy in the canine CSNB model prior to its clinical application.
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Affiliation(s)
- Kei Takahashi
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer C Kwok
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yu Sato
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gustavo D Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Keiko Miyadera
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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4
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Zin EA, Ozturk BE, Dalkara D, Byrne LC. Developing New Vectors for Retinal Gene Therapy. Cold Spring Harb Perspect Med 2023; 13:a041291. [PMID: 36987583 PMCID: PMC10691475 DOI: 10.1101/cshperspect.a041291] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Since their discovery over 55 years ago, adeno-associated virus (AAV) vectors have become powerful tools for experimental and therapeutic in vivo gene delivery, particularly in the retina. Increasing knowledge of AAV structure and biology has propelled forward the development of engineered AAV vectors with improved abilities for gene delivery. However, major obstacles to safe and efficient therapeutic gene delivery remain, including tropism, inefficient and untargeted gene delivery, and limited carrying capacity. Additional improvements to AAV vectors will be required to achieve therapeutic benefit while avoiding safety issues. In this review, we provide an overview of recent methods for engineering-enhanced AAV capsids, as well as remaining challenges that must be overcome to achieve optimized therapeutic gene delivery in the eye.
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Affiliation(s)
- Emilia A Zin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Bilge E Ozturk
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Leah C Byrne
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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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: 19] [Impact Index Per Article: 19.0] [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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Treatment with MDL 72527 Ameliorated Clinical Symptoms, Retinal Ganglion Cell Loss, Optic Nerve Inflammation, and Improved Visual Acuity in an Experimental Model of Multiple Sclerosis. Cells 2022; 11:cells11244100. [PMID: 36552864 PMCID: PMC9776605 DOI: 10.3390/cells11244100] [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: 09/25/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Multiple Sclerosis (MS) is a highly disabling neurological disease characterized by inflammation, neuronal damage, and demyelination. Vision impairment is one of the major clinical features of MS. Previous studies from our lab have shown that MDL 72527, a pharmacological inhibitor of spermine oxidase (SMOX), is protective against neurodegeneration and inflammation in the models of diabetic retinopathy and excitotoxicity. In the present study, utilizing the experimental autoimmune encephalomyelitis (EAE) model of MS, we determined the impact of SMOX blockade on retinal neurodegeneration and optic nerve inflammation. The increased expression of SMOX observed in EAE retinas was associated with a significant loss of retinal ganglion cells, degeneration of synaptic contacts, and reduced visual acuity. MDL 72527-treated mice exhibited markedly reduced motor deficits, improved neuronal survival, the preservation of synapses, and improved visual acuity compared to the vehicle-treated group. The EAE-induced increase in macrophage/microglia was markedly reduced by SMOX inhibition. Upregulated acrolein conjugates in the EAE retina were decreased through MDL 72527 treatment. Mechanistically, the EAE-induced ERK-STAT3 signaling was blunted by SMOX inhibition. In conclusion, our studies demonstrate the potential benefits of targeting SMOX to treat MS-mediated neuroinflammation and vision loss.
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7
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Rotov AY, Firsov ML. Optogenetic Prosthetization of Retinal Bipolar Cells. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022060011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abstract
Although the experience of optogenetic retinal prosthetics
in animal models dates back to more than 16 years, the first results
obtained on humans have only been reported in the last year. Over this
period, the main challenges of prosthetics became clear and the
approaches to their solution were proposed. In this review, we aim
to present the achievements in the field of optogenetic prosthetization
of retinal bipolar cells with a focus mainly on relatively recent
publications. The review addresses the advantages and disadvantages
of bipolar cell prosthetics as compared to the alternative target,
retinal ganglion cells, and provides a comparative analysis of the
effectiveness of ionotropic light-sensitive proteins (channelrhodopsins)
or metabotropic receptors (rhodopsins) as prosthetic tools.
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8
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Bipolar cell targeted optogenetic gene therapy restores parallel retinal signaling and high-level vision in the degenerated retina. Commun Biol 2022; 5:1116. [PMID: 36266533 PMCID: PMC9585040 DOI: 10.1038/s42003-022-04016-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 09/21/2022] [Indexed: 11/09/2022] Open
Abstract
Optogenetic gene therapies to restore vision are in clinical trials. Whilst current clinical approaches target the ganglion cells, the output neurons of the retina, new molecular tools enable efficient targeting of the first order retinal interneurons, the bipolar cells, with the potential to restore a higher quality of vision. Here we investigate retinal signaling and behavioral vision in blind mice treated with bipolar cell targeted optogenetic gene therapies. All tested tools, including medium-wave opsin, Opto-mGluR6, and two new melanopsin based chimeras restored visual acuity and contrast sensitivity. The best performing opsin was a melanopsin-mGluR6 chimera, which in some cases restored visual acuities and contrast sensitivities that match wild-type animals. Light responses from the ganglion cells were robust with diverse receptive-field types, inferring elaborate inner retinal signaling. Our results highlight the potential of bipolar cell targeted optogenetics to recover high-level vision in human patients with end-stage retinal degenerations. A chimeric Mela(CTmGluR6) optogenetic tool has the potential to restore vision and signaling in a mouse model of degenerative retinal disease.
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Vijayasarathy C, Zeng Y, Marangoni D, Dong L, Pan ZH, Simpson EM, Fariss RN, Sieving PA. Targeted Expression of Retinoschisin by Retinal Bipolar Cells in XLRS Promotes Resolution of Retinoschisis Cysts Sans RS1 From Photoreceptors. Invest Ophthalmol Vis Sci 2022; 63:8. [PMID: 36227606 PMCID: PMC9583743 DOI: 10.1167/iovs.63.11.8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 09/18/2022] [Indexed: 01/14/2023] Open
Abstract
Purpose Loss of retinoschisin (RS1) function underlies X-linked retinoschisis (XLRS) pathology. In the retina, both photoreceptor inner segments and bipolar cells express RS1. However, the loss of RS1 function causes schisis primarily in the inner retina. To understand these cell type-specific phenotypes, we decoupled RS1 effects in bipolar cells from that in photoreceptors. Methods Bipolar cell transgene RS1 expression was achieved using two inner retina-specific promoters: (1) a minimal promoter engineered from glutamate receptor, metabotropic glutamate receptor 6 gene (mini-mGluR6/ Grm6) and (2) MiniPromoter (Ple155). Adeno-associated virus vectors encoding RS1 gene under either the mini-mGluR6 or Ple-155 promoter were delivered to the XLRS mouse retina through intravitreal or subretinal injection on postnatal day 14. Retinal structure and function were assessed 5 weeks later: immunohistochemistry for morphological characterization, optical coherence tomography and electroretinography (ERG) for structural and functional evaluation. Results Immunohistochemical analysis of RS1expression showed that expression with the MiniPromoter (Ple155) was heavily enriched in bipolar cells. Despite variations in vector penetrance and gene transfer efficiency across the injected retinas, those retinal areas with robust bipolar cell RS1 expression showed tightly packed bipolar cells with fewer cavities and marked improvement in inner retinal structure and synaptic function as judged by optical coherence tomography and electroretinography, respectively. Conclusions These results demonstrate that RS1 gene expression primarily in bipolar cells of the XLRS mouse retina, independent of photoreceptor expression, can ameliorate retinoschisis structural pathology and provide further evidence of RS1 role in cell adhesion.
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Affiliation(s)
- Camasamudram Vijayasarathy
- Section for Translational Research in Retinal and Macular Degeneration, National Institutes of Health, Bethesda, Maryland, United States
| | - Yong Zeng
- Section for Translational Research in Retinal and Macular Degeneration, National Institutes of Health, Bethesda, Maryland, United States
| | - Dario Marangoni
- Section for Translational Research in Retinal and Macular Degeneration, National Institutes of Health, Bethesda, Maryland, United States
| | - Lijin Dong
- Genetic Engineering Facility, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Zhuo-Hua Pan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Elizabeth M. Simpson
- Centre for Molecular Medicine and Therapeutics at BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert N. Fariss
- Biological Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Paul A. Sieving
- Section for Translational Research in Retinal and Macular Degeneration, National Institutes of Health, Bethesda, Maryland, United States
- Center for Ocular Regenerative Therapy, Department of Ophthalmology, University of California Davis, United States
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10
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Spampinato GLB, Ronzitti E, Zampini V, Ferrari U, Trapani F, Khabou H, Agraval A, Dalkara D, Picaud S, Papagiakoumou E, Marre O, Emiliani V. All-optical inter-layers functional connectivity investigation in the mouse retina. CELL REPORTS METHODS 2022; 2:100268. [PMID: 36046629 PMCID: PMC9421538 DOI: 10.1016/j.crmeth.2022.100268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/03/2022] [Accepted: 07/19/2022] [Indexed: 06/01/2023]
Abstract
We developed a multi-unit microscope for all-optical inter-layers circuits interrogation. The system performs two-photon (2P) functional imaging and 2P multiplexed holographic optogenetics at axially distinct planes. We demonstrated the capability of the system to map, in the mouse retina, the functional connectivity between rod bipolar cells (RBCs) and ganglion cells (GCs) by activating single or defined groups of RBCs while recording the evoked response in the GC layer with cell-type specificity and single-cell resolution. We then used a logistic model to probe the functional connectivity between cell types by deriving the "cellular receptive field" describing how RBCs impact each GC type. With the capability to simultaneously image and control neuronal activity at axially distinct planes, the system enables a precise interrogation of multi-layered circuits. Understanding this information transfer is a promising avenue to dissect complex neural circuits and understand the neural basis of computations.
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Affiliation(s)
| | - Emiliano Ronzitti
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Valeria Zampini
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Ulisse Ferrari
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Francesco Trapani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Hanen Khabou
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | | | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | | | - Olivier Marre
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Valentina Emiliani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
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11
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Gilhooley MJ, Lindner M, Palumaa T, Hughes S, Peirson SN, Hankins MW. A systematic comparison of optogenetic approaches to visual restoration. Mol Ther Methods Clin Dev 2022; 25:111-123. [PMID: 35402632 PMCID: PMC8956963 DOI: 10.1016/j.omtm.2022.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/04/2022] [Indexed: 02/06/2023]
Abstract
During inherited retinal degenerations (IRDs), vision is lost due to photoreceptor cell death; however, a range of optogenetic tools have been shown to restore light responses in animal models. Restored response characteristics vary between tools and the neuronal cell population to which they are delivered: the interplay between these is complex, but targeting upstream neurons (such as retinal bipolar cells) may provide functional benefit by retaining intraretinal signal processing. In this study, our aim was to compare two optogenetic tools: mammalian melanopsin (hOPN4) and microbial red-shifted channelrhodopsin (ReaChR) expressed within two subpopulations of surviving cells in a degenerate retina. Intravitreal adeno-associated viral vectors and mouse models utilising the Cre/lox system restricted expression to populations dominated by bipolar cells or retinal ganglion cells and was compared with non-targeted delivery using the chicken beta actin (CBA) promoter. In summary, we found bipolar-targeted optogenetic tools produced faster kinetics and flatter intensity-response relationships compared with non-targeted or retinal-ganglion-cell-targeted hOPN4. Hence, optogenetic tools of both mammalian and microbial origins show advantages when targeted to bipolar cells. This demonstrates the advantage of bipolar-cell-targeted optogenetics for vision restoration in IRDs. We therefore developed a bipolar-cell-specific gene delivery system employing a compressed promoter with the potential for clinical translation.
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Affiliation(s)
- Michael J. Gilhooley
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- The Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK
- Moorfields Eye Hospital, 162, City Road, London EC1V 2PD, UK
| | - Moritz Lindner
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps University, Deutschhausstrasse 1-2, Marburg 35037, Germany
| | - Teele Palumaa
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- East Tallinn Central Hospital Eye Clinic, Ravi 18, 10138 Tallinn, Estonia
| | - Steven Hughes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
| | - Stuart N. Peirson
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
| | - Mark W. Hankins
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Jules Thorne SCNi, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK
- Corresponding author Mark W. Hankins, Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX1 3QU, UK.
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12
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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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13
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Kim S, Roh H, Im M. Artificial Visual Information Produced by Retinal Prostheses. Front Cell Neurosci 2022; 16:911754. [PMID: 35734216 PMCID: PMC9208577 DOI: 10.3389/fncel.2022.911754] [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: 04/03/2022] [Accepted: 05/18/2022] [Indexed: 11/18/2022] Open
Abstract
Numerous retinal prosthetic systems have demonstrated somewhat useful vision can be restored to individuals who had lost their sight due to outer retinal degenerative diseases. Earlier prosthetic studies have mostly focused on the confinement of electrical stimulation for improved spatial resolution and/or the biased stimulation of specific retinal ganglion cell (RGC) types for selective activation of retinal ON/OFF pathway for enhanced visual percepts. To better replicate normal vision, it would be also crucial to consider information transmission by spiking activities arising in the RGC population since an incredible amount of visual information is transferred from the eye to the brain. In previous studies, however, it has not been well explored how much artificial visual information is created in response to electrical stimuli delivered by microelectrodes. In the present work, we discuss the importance of the neural information for high-quality artificial vision. First, we summarize the previous literatures which have computed information transmission rates from spiking activities of RGCs in response to visual stimuli. Second, we exemplify a couple of studies which computed the neural information from electrically evoked responses. Third, we briefly introduce how information rates can be computed in the representative two ways - direct method and reconstruction method. Fourth, we introduce in silico approaches modeling artificial retinal neural networks to explore the relationship between amount of information and the spiking patterns. Lastly, we conclude our review with clinical implications to emphasize the necessity of considering visual information transmission for further improvement of retinal prosthetics.
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Affiliation(s)
- Sein Kim
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
| | - Hyeonhee Roh
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, South Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, South Korea
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14
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Rudnick ND, Kim LA, Comander J. Adeno-associated Viral Vectors in the Retina: Delivering Gene Therapy to the Right Destination. Int Ophthalmol Clin 2022; 62:215-229. [PMID: 35325920 DOI: 10.1097/iio.0000000000000416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
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15
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Miyadera K, Santana E, Roszak K, Iffrig S, Visel M, Iwabe S, Boyd RF, Bartoe JT, Sato Y, Gray A, Ripolles-Garcia A, Dufour VL, Byrne LC, Flannery JG, Beltran WA, Aguirre GD. Targeting ON-bipolar cells by AAV gene therapy stably reverses LRIT3-congenital stationary night blindness. Proc Natl Acad Sci U S A 2022; 119:e2117038119. [PMID: 35316139 PMCID: PMC9060458 DOI: 10.1073/pnas.2117038119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 01/10/2022] [Indexed: 01/08/2023] Open
Abstract
SignificanceCanine models of inherited retinal diseases have helped advance adeno-associated virus (AAV)-based gene therapies targeting specific cells in the outer retina for treating blinding diseases in patients. However, therapeutic targeting of diseases such as congenital stationary night blindness (CSNB) that exhibit defects in ON-bipolar cells (ON-BCs) of the midretina remains underdeveloped. Using a leucine-rich repeat, immunoglobulin-like and transmembrane domain 3 (LRIT3) mutant canine model of CSNB exhibiting ON-BC dysfunction, we tested the ability of cell-specific AAV capsids and promotors to specifically target ON-BCs for gene delivery. Subretinal injection of one vector demonstrated safety and efficacy with robust and stable rescue of electroretinography signals and night vision up to 1 y, paving the way for clinical trials in patients.
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Affiliation(s)
- Keiko Miyadera
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Evelyn Santana
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Karolina Roszak
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Sommer Iffrig
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Meike Visel
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Simone Iwabe
- Ophthalmology Services, Charles River Laboratories, Mattawan, MI 49071
| | - Ryan F. Boyd
- Ophthalmology Services, Charles River Laboratories, Mattawan, MI 49071
| | - Joshua T. Bartoe
- Ophthalmology Services, Charles River Laboratories, Mattawan, MI 49071
| | - Yu Sato
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Alexa Gray
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ana Ripolles-Garcia
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Valérie L. Dufour
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Leah C. Byrne
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | - John G. Flannery
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - William A. Beltran
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Gustavo D. Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
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16
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Bansal A, Shikha S, Zhang Y. Towards translational optogenetics. Nat Biomed Eng 2022; 7:349-369. [PMID: 35027688 DOI: 10.1038/s41551-021-00829-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 10/21/2021] [Indexed: 02/07/2023]
Abstract
Optogenetics is widely used to interrogate the neural circuits underlying disease and has most recently been harnessed for therapeutic applications. The optogenetic toolkit consists of light-responsive proteins that modulate specific cellular functions, vectors for the delivery of the transgenes that encode the light-responsive proteins to targeted cellular populations, and devices for the delivery of light of suitable wavelengths at effective fluence rates. A refined toolkit with a focus towards translational uses would include efficient and safer viral and non-viral gene-delivery vectors, increasingly red-shifted photoresponsive proteins, nanomaterials that efficiently transduce near-infrared light deep into tissue, and wireless implantable light-delivery devices that allow for spatiotemporally precise interventions at clinically relevant tissue depths. In this Review, we examine the current optogenetics toolkit and the most notable preclinical and translational uses of optogenetics, and discuss future methodological and translational developments and bottlenecks.
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Affiliation(s)
- Akshaya Bansal
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore
| | - Swati Shikha
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore
| | - Yong Zhang
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore. .,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore. .,NUS Suzhou Research Institute, Suzhou, Jiangsu, P. R. China.
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17
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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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18
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Kralik J, Kleinlogel S. Functional Availability of ON-Bipolar Cells in the Degenerated Retina: Timing and Longevity of an Optogenetic Gene Therapy. Int J Mol Sci 2021; 22:ijms222111515. [PMID: 34768944 PMCID: PMC8584043 DOI: 10.3390/ijms222111515] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/13/2021] [Accepted: 10/23/2021] [Indexed: 01/19/2023] Open
Abstract
Degenerative diseases of the retina are responsible for the death of photoreceptors and subsequent loss of vision in patients. Nevertheless, the inner retinal layers remain intact over an extended period of time, enabling the restoration of light sensitivity in blind retinas via the expression of optogenetic tools in the remaining retinal cells. The chimeric Opto-mGluR6 protein represents such a tool. With exclusive ON-bipolar cell expression, it combines the light-sensitive domains of melanopsin and the intracellular domains of the metabotropic glutamate receptor 6 (mGluR6), which naturally mediates light responses in these cells. Albeit vision restoration in blind mice by Opto-mGluR6 delivery was previously shown, much is left to be explored in regard to the effects of the timing of the treatment in the degenerated retina. We performed a functional evaluation of Opto-mGluR6-treated murine blind retinas using multi-electrode arrays (MEAs) and observed long-term functional preservation in the treated retinas, as well as successful therapeutical intervention in later stages of degeneration. Moreover, the treatment decreased the inherent retinal hyperactivity of the degenerated retinas to levels undistinguishable from healthy controls. Finally, we observed for the first time micro electroretinograms (mERGs) in optogenetically treated animals, corroborating the origin of Opto-mGluR6 signalling at the level of mGluR6 of ON-bipolar cells.
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19
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Han IC, Burnight ER, Kaalberg EE, Boyce TM, Stone EM, Fingert JH, Mullins RF, Tucker BA, Wiley LA. Chimeric Helper-Dependent Adenoviruses Transduce Retinal Ganglion Cells and Müller Cells in Human Retinal Explants. J Ocul Pharmacol Ther 2021; 37:575-579. [PMID: 34597181 DOI: 10.1089/jop.2021.0057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Purpose: Despite numerous recent advances in retinal gene therapy using adeno-associated viruses (AAVs) as delivery vectors, there remains a crucial need to identify viral vectors with the ability to transduce specific retinal cell types and that have a larger carrying capacity than AAV. In this study, we evaluate the retinal tropism of 2 chimeric helper-dependent adenoviruses (HDAds), helper-dependent adenovirus serotype 5 (HDAd5)/3 and HDAd5/35, both ex vivo using human retinal explants and in vivo using rats. Methods: We transduced cultured human retinal explants with HDAd5/3 and HDAd5/35 carrying an eGFP vector and evaluated tropism and transduction efficiency using immunohistochemistry. To assess in vivo transduction efficiency, subretinal injections were performed in wild-type Sprague-Dawley rats. For both explants and subretinal injections, we delivered 10 μL (1 × 106 vector genomes/mL) and assessed tropism at 7- and 14-days post-transduction, respectively. Results: HDAd5/3 and HDAd5/35 both transduced human retinal ganglion cells (RGCs) and Müller cells, but not photoreceptors, in human retinal explants. However, subretinal injections in albino rats resulted in transduction of the retinal pigmented epithelium only, highlighting species-specific differences in retinal tropism and the value of a human explant model when testing vectors for eventual human gene therapy. Conclusions: Chimeric HDAds are promising candidates for the delivery of large genes, multiple genes, or neuroprotective factors to Müller cells and RGCs. These vectors may have utility for targeted therapy of neurodegenerative diseases primarily involving retinal ganglion or Müller cell types, such as glaucoma or macular telangiectasia type 2.
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Affiliation(s)
- Ian C Han
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Erin R Burnight
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Emily E Kaalberg
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Timothy M Boyce
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Edwin M Stone
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - John H Fingert
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Robert F Mullins
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Budd A Tucker
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Luke A Wiley
- The University of Iowa Institute for Vision Research, Iowa City, Iowa, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
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20
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Cui S, Ganjawala TH, Abrams GW, Pan ZH. Effect of Proteasome Inhibitors on the AAV-Mediated Transduction Efficiency in Retinal Bipolar Cells. Curr Gene Ther 2021; 19:404-412. [PMID: 32072884 DOI: 10.2174/1566523220666200211111326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/29/2020] [Accepted: 01/30/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Adeno-associated Virus (AAV) vectors are the most promising vehicles for therapeutic gene delivery to the retina. To develop a practical gene delivery tool, achieving high AAV transduction efficiency in specific cell types is often required. AAV-mediated targeted expression in retinal bipolar cells is needed in certain applications such as optogenetic therapy, however, the transduction efficiency driven by endogenous cell-specific promoters is usually low. Methods that can improve AAV transduction efficiency in bipolar cells need to be developed. OBJECTIVE The study aimed to examine the effect of proteasome inhibitors on AAV-mediated transduction efficiency in retinal bipolar cells. METHODS Quantitative analysis of fluorescent reporter protein expression was performed to assess the effect of two proteasome inhibitors, doxorubicin and MG132, on AAV-mediated transduction efficiency in retinal bipolar cells in mice. RESULTS Our results showed that doxorubicin can increase the AAV transduction efficiency in retinal bipolar cells in a dose-dependent manner. We also observed doxorubicin-mediated cytotoxicity in retinal neurons, but the cytotoxicity could be mitigated by the coapplication of dexrazoxane. Three months after the coapplication of doxorubicin (300 μM) and dexrazoxane, the AAV transduction efficiency in retinal bipolar cells increased by 33.8% and no cytotoxicity was observed in all the layers of the retina. CONCLUSION Doxorubicin could enhance the AAV transduction efficiency in retinal bipolar cells in vivo. The potential long-term cytotoxicity caused by doxorubicin to retinal neurons could be partially mitigated by dexrazoxane. The coapplication of doxorubicin and dexrazoxane may serve as a potential adjuvant regimen for improving AAV transduction efficiency in retinal bipolar cells.
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Affiliation(s)
- Shengjie Cui
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, School of Medicine, Detroit, MI, 48201, United States
| | - Tushar H Ganjawala
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, School of Medicine, Detroit, MI, 48201, United States
| | - Gary W Abrams
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, School of Medicine, Detroit, MI, 48201, United States
| | - Zhuo-Hua Pan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, School of Medicine, Detroit, MI, 48201, United States
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21
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Gilhooley MJ, Hickey DG, Lindner M, Palumaa T, Hughes S, Peirson SN, MacLaren RE, Hankins MW. ON-bipolar cell gene expression during retinal degeneration: Implications for optogenetic visual restoration. Exp Eye Res 2021; 207:108553. [PMID: 33811915 PMCID: PMC8214074 DOI: 10.1016/j.exer.2021.108553] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 03/08/2021] [Accepted: 03/23/2021] [Indexed: 12/28/2022]
Abstract
Purpose Retinal bipolar cells survive even in the later stages of inherited retinal degenerations (IRDs) and so are attractive targets for optogenetic approaches to vision restoration. However, it is not known to what extent the remodelling that these cells undergo during degeneration affects their function. Specifically, it is unclear if they are free from metabolic stress, receptive to adeno-associated viral vectors, suitable for opsin-based optogenetic tools and able to propagate signals by releasing neurotransmitter. Methods Fluorescence activated cell sorting (FACS) was performed to isolate labelled bipolar cells from dissociated retinae of litter-mates with or without the IRD mutation Pde6brd1/rd1 selectively expressing an enhanced yellow fluorescent protein (EYFP) as a marker in ON-bipolar cells. Subsequent mRNA extraction allowed Illumina® microarray comparison of gene expression in bipolar cells from degenerate to those of wild type retinae. Changes in four candidate genes were further investigated at the protein level using retinal immunohistochemistry over the course of degeneration. Results A total of sixty differentially expressed transcripts reached statistical significance: these did not include any genes directly associated with native primary bipolar cell signalling, nor changes consistent with metabolic stress. Four significantly altered genes (Srm2, Slf2, Anxa7 & Cntn1), implicated in synaptic remodelling, neurotransmitter release and viral vector entry had immunohistochemical staining colocalising with ON-bipolar cell markers and varying over the course of degeneration. Conclusion Our findings suggest relatively few gene expression changes in the context of degeneration: that despite remodelling, bipolar cells are likely to remain viable targets for optogenetic vision restoration. In addition, several genes where changes were seen could provide a basis for investigations to enhance the efficacy of optogenetic therapies. Bipolar cells are attractive targets for therapeutic optogenetics in IRDs. This is the first cell specific transcriptomic analysis of bipolar cells in an IRD model. Bipolar cells maintain expression of genes essential to act as targets for optogenetics. Protein staining relating to four candidate genes (Anxa7, Cntn1, Srm2, Sulf2) is confirmed using immunohistochemistry.
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Affiliation(s)
- Michael J Gilhooley
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom; The Oxford Eye Hospital, Oxford, OX3 9DU, United Kingdom; Moorfields Eye Hospital, London, EC1V 2PD, United Kingdom
| | - Doron G Hickey
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom; Royal Victorian Eye and Ear Hospital, Melbourne, 002, Australia
| | - Moritz Lindner
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom; The Oxford Eye Hospital, Oxford, OX3 9DU, United Kingdom; Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps University, Deutschhausstrasse 1-2, Marburg, 35037, Germany
| | - Teele Palumaa
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom
| | - Steven Hughes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom; Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom; The Oxford Eye Hospital, Oxford, OX3 9DU, United Kingdom; Moorfields Eye Hospital, London, EC1V 2PD, United Kingdom
| | - Mark W Hankins
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom; Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, OX1 3RE, United Kingdom.
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22
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Varin J, Bouzidi N, Dias MMDS, Pugliese T, Michiels C, Robert C, Desrosiers M, Sahel JA, Audo I, Dalkara D, Zeitz C. Restoration of mGluR6 Localization Following AAV-Mediated Delivery in a Mouse Model of Congenital Stationary Night Blindness. Invest Ophthalmol Vis Sci 2021; 62:24. [PMID: 33729473 PMCID: PMC7980044 DOI: 10.1167/iovs.62.3.24] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Complete congenital stationary night blindness (cCSNB) is an incurable inherited retinal disorder characterized by an ON-bipolar cell (ON-BC) defect. GRM6 mutations are the third most prevalent cause of cCSNB. The Grm6-/- mouse model mimics the human phenotype, showing no b-wave in the electroretinogram (ERG) and a loss of mGluR6 and other proteins of the same cascade at the outer plexiform layer (OPL). Our aim was to restore protein localization and function in Grm6-/- adult mice targeting specifically ON-BCs or the whole retina. Methods Adeno-associated virus-encoding Grm6 under two different promoters (GRM6-Grm6 and CAG-Grm6) were injected intravitreally in P15 Grm6-/- mice. ERG recordings at 2 and 4 months were performed in Grm6+/+, untreated and treated Grm6-/- mice. Similarly, immunolocalization studies were performed on retinal slices before or after treatment using antibodies against mGluR6, TRPM1, GPR179, RGS7, RGS11, Gβ5, and dystrophin. Results Following treatment, mGluR6 was localized to the dendritic tips of ON-BCs when expressed with either promoter. The relocalization efficiency in mGluR6-transduced retinas at the OPL was 2.5% versus 11% when the GRM6-Grm6 and CAG-Grm6 were used, respectively. Albeit no functional rescue was seen in ERGs, relocalization of TRPM1, GPR179, and Gβ5 was also noted using both constructs. The restoration of the localization of RGS7, RGS11, and dystrophin was more obvious in retinas treated with GRM6-Grm6 than in retinas treated with CAG-Grm6. Conclusions Our findings show the potential of treating cCSNB with GRM6 mutations; however, it appears that the transduction rate must be improved to restore visual function.
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Affiliation(s)
- Juliette Varin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Nassima Bouzidi
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | | | - Thomas Pugliese
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | | | - Camille Robert
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | | | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.,CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC 1423, Paris, France.,Fondation Ophtalmologique Adolphe de Rothschild, Paris, France.,Academie des Sciences, Institut de France, Paris, France.,Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.,CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC 1423, Paris, France.,Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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23
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Murenu E, Pavlou M, Richter L, Rapti K, Just S, Cehajic-Kapetanovic J, Tafrishi N, Hayes A, Scholey R, Lucas R, Büning H, Grimm D, Michalakis S. A universal protocol for isolating retinal ON bipolar cells across species via fluorescence-activated cell sorting. Mol Ther Methods Clin Dev 2021; 20:587-600. [PMID: 33665228 PMCID: PMC7895692 DOI: 10.1016/j.omtm.2021.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/19/2021] [Indexed: 11/17/2022]
Abstract
Inherited retinal dystrophies (IRDs) are characterized by progressive degeneration and loss of light-sensing photoreceptors. The most promising therapeutic approach for IRDs is gene supplementation therapy using viral vectors, which requires the presence of viable photoreceptors at the time of intervention. At later disease stages, photoreceptors are lost and can no longer be rescued with this approach. For these patients, conferring light-sensing abilities to the remaining interneurons of the ON circuit (i.e., ON bipolar cells) using optogenetic tools poses an alternative treatment strategy. Such treatments, however, are hampered by the lack of efficient gene delivery tools targeting ON bipolar cells, which in turn rely on the effective isolation of these cells to facilitate tool development. Herein, we describe a method to selectively isolate ON bipolar cells via fluorescence-activated cell sorting (FACS), based on the expression of two intracellular markers. We show that the method is compatible with highly sensitive downstream analyses and suitable for the isolation of ON bipolar cells from healthy as well as degenerated mouse retinas. Moreover, we demonstrate that this approach works effectively using non-human primate (NHP) retinal tissue, thereby offering a reliable pipeline for universal screening strategies that do not require inter-species adaptations or transgenic animals.
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Affiliation(s)
- Elisa Murenu
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
- Department of Pharmacy, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Marina Pavlou
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
- Department of Pharmacy, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Lisa Richter
- Core Facility Flow Cytometry, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Kleopatra Rapti
- Department of Infectious Diseases/Virology, Medical Faculty, University of Heidelberg, 69120 Heidelberg, Germany
- BioQuant Center, University of Heidelberg, 69120 Heidelberg, Germany
| | - Sabrina Just
- Laboratory for Infection Biology and Gene Transfer, Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
- REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, Oxford University and Oxford University Hospitals, Oxford OX3 9DU, UK
| | - Neda Tafrishi
- Core Facility Flow Cytometry, Gene Center, BioSysM, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Andrew Hayes
- Center for Biological Timing & School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PL, UK
| | - Rachel Scholey
- Center for Biological Timing & School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PL, UK
| | - Robert Lucas
- Center for Biological Timing & School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PL, UK
| | - Hildegard Büning
- Laboratory for Infection Biology and Gene Transfer, Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
- REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), partner site, Hannover, Germany
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Medical Faculty, University of Heidelberg, 69120 Heidelberg, Germany
- BioQuant Center, University of Heidelberg, 69120 Heidelberg, Germany
- German Center for Infection Research (DZIF) and German Center for Cardiovascular Research (DZHK), partner site, Heidelberg, Germany
| | - Stylianos Michalakis
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
- Department of Pharmacy, Ludwig-Maximilians-University Munich, 81377 Munich, Germany
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24
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AAV Induced Expression of Human Rod and Cone Opsin in Bipolar Cells of a Mouse Model of Retinal Degeneration. BIOMED RESEARCH INTERNATIONAL 2021; 2021:1-8. [PMID: 35465048 PMCID: PMC7612646 DOI: 10.1155/2021/4014797] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Vision loss caused by inherited retinal degeneration affects millions of people worldwide, and clinical trials involving gene supplementation strategies are ongoing for select forms of the disease. When early therapeutic intervention is not possible and patients suffer complete loss of their photoreceptor cells, there is an opportunity for vision restoration techniques, including optogenetic therapy. This therapy provides expression of light-sensitive molecules to surviving cell types of the retina, enabling light perception through residual neuronal pathways. To this end, the bipolar cells make an obvious optogenetic target to enable upstream processing of visual signal in the retina. However, while AAV transduction of the bipolar cells has been described, the expression of human opsins in these cell types within a model of retinal degeneration (rd1) has been less successful. In this study, we have expanded the optogenetic toolkit and shown successful expression of human rhodopsin driven by an ON-bipolar cell promoter (Grm6) in the rd1 mouse model using modified AAV capsids (AAV2.4YF, AAV8.BP2, and AAV2.7m8) delivered via intraocular injection. We also show the first presentation of ectopic expression of human cone opsin in the bipolar cells of rd1 mice. These data provide evidence of an expansion of the optogenetic toolkit with the potential to restore useful visual function, setting the stage for future trials in human patients.
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25
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Korecki AJ, Cueva-Vargas JL, Fornes O, Agostinone J, Farkas RA, Hickmott JW, Lam SL, Mathelier A, Zhou M, Wasserman WW, Di Polo A, Simpson EM. Human MiniPromoters for ocular-rAAV expression in ON bipolar, cone, corneal, endothelial, Müller glial, and PAX6 cells. Gene Ther 2021; 28:351-372. [PMID: 33531684 PMCID: PMC8222000 DOI: 10.1038/s41434-021-00227-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/17/2020] [Accepted: 01/15/2021] [Indexed: 02/06/2023]
Abstract
Small and cell-type restricted promoters are important tools for basic and preclinical research, and clinical delivery of gene therapies. In clinical gene therapy, ophthalmic trials have been leading the field, with over 50% of ocular clinical trials using promoters that restrict expression based on cell type. Here, 19 human DNA MiniPromoters were bioinformatically designed for rAAV, tested by neonatal intravenous delivery in mouse, and successful MiniPromoters went on to be tested by intravitreal, subretinal, intrastromal, and/or intravenous delivery in adult mouse. We present promoter development as an overview for each cell type, but only show results in detail for the recommended MiniPromoters: Ple265 and Ple341 (PCP2) ON bipolar, Ple349 (PDE6H) cone, Ple253 (PITX3) corneal stroma, Ple32 (CLDN5) endothelial cells of the blood-retina barrier, Ple316 (NR2E1) Müller glia, and Ple331 (PAX6) PAX6 positive. Overall, we present a resource of new, redesigned, and improved MiniPromoters for ocular gene therapy that range in size from 784 to 2484 bp, and from weaker, equal, or stronger in strength relative to the ubiquitous control promoter smCBA. All MiniPromoters will be useful for therapies involving small regulatory RNA and DNA, and proteins ranging from 517 to 1084 amino acids, representing 62.9-90.2% of human proteins.
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Affiliation(s)
- Andrea J. Korecki
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Jorge L. Cueva-Vargas
- grid.14848.310000 0001 2292 3357Department of Neuroscience, University of Montreal Hospital Research Centre, University of Montreal, Montreal, QC Canada
| | - Oriol Fornes
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Jessica Agostinone
- grid.14848.310000 0001 2292 3357Department of Neuroscience, University of Montreal Hospital Research Centre, University of Montreal, Montreal, QC Canada
| | - Rachelle A. Farkas
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
| | - Jack W. Hickmott
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
| | - Siu Ling Lam
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Anthony Mathelier
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Michelle Zhou
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Wyeth W. Wasserman
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
| | - Adriana Di Polo
- grid.14848.310000 0001 2292 3357Department of Neuroscience, University of Montreal Hospital Research Centre, University of Montreal, Montreal, QC Canada
| | - Elizabeth M. Simpson
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
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26
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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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27
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Andrews MR. Gene therapy in the CNS-one size does not fit all. Gene Ther 2020; 28:393-395. [PMID: 32978509 DOI: 10.1038/s41434-020-00196-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/25/2020] [Accepted: 09/18/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Melissa R Andrews
- School of Biological Sciences, University of Southampton, Southampton, SO171BJ, UK.
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28
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MacLaren RE. A 2020 vision of ocular gene therapy. Gene Ther 2020; 28:217-219. [PMID: 32601358 DOI: 10.1038/s41434-020-0170-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/04/2020] [Accepted: 06/23/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford and Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, West Wing John Radcliffe Hospital, Oxford, OX3 9DU, UK.
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29
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Buck TM, Wijnholds J. Recombinant Adeno-Associated Viral Vectors (rAAV)-Vector Elements in Ocular Gene Therapy Clinical Trials and Transgene Expression and Bioactivity Assays. Int J Mol Sci 2020; 21:E4197. [PMID: 32545533 PMCID: PMC7352801 DOI: 10.3390/ijms21124197] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 02/06/2023] Open
Abstract
Inherited retinal dystrophies and optic neuropathies cause chronic disabling loss of visual function. The development of recombinant adeno-associated viral vectors (rAAV) gene therapies in all disease fields have been promising, but the translation to the clinic has been slow. The safety and efficacy profiles of rAAV are linked to the dose of applied vectors. DNA changes in the rAAV gene cassette affect potency, the expression pattern (cell-specificity), and the production yield. Here, we present a library of rAAV vectors and elements that provide a workflow to design novel vectors. We first performed a meta-analysis on recombinant rAAV elements in clinical trials (2007-2020) for ocular gene therapies. We analyzed 33 unique rAAV gene cassettes used in 57 ocular clinical trials. The rAAV gene therapy vectors used six unique capsid variants, 16 different promoters, and six unique polyadenylation sequences. Further, we compiled a list of promoters, enhancers, and other sequences used in current rAAV gene cassettes in preclinical studies. Then, we give an update on pro-viral plasmid backbones used to produce the gene therapy vectors, inverted terminal repeats, production yield, and rAAV safety considerations. Finally, we assess rAAV transgene and bioactivity assays applied to cells or organoids in vitro, explants ex vivo, and clinical studies.
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Affiliation(s)
- Thilo M. Buck
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands;
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands;
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
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30
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Comparison of AAV-Mediated Optogenetic Vision Restoration between Retinal Ganglion Cell Expression and ON Bipolar Cell Targeting. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 18:15-23. [PMID: 32548211 PMCID: PMC7287188 DOI: 10.1016/j.omtm.2020.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 01/06/2023]
Abstract
The loss of photoreceptors in individuals with retinal degenerative diseases leads to partial or complete blindness. Optogenetic therapy is a promising approach for restoring vision to the blind. Multiple strategies have been employed by targeting genetically encoded light sensors, particularly channelrhodopsins, to surviving retinal neurons in animal models. In particular, the strategy of targeting retinal bipolar cells has commonly been expected to result in better vision than ubiquitous expression in retinal ganglion cells. However, a direct comparison of the channelrhodopsin-restored vision between these two strategies has not been performed. Here, we compared the restored visual functions achieved by adeno-associated virus (AAV)-mediated expression of a channelrhodopsin in ON-type bipolar cells and retinal ganglion cells driven by an improved mGluR6 promoter and a CAG promoter, respectively, in a blind mouse model by performing electrophysiological recordings and behavioral assessments. Unexpectedly, the efficacy of the restored vision based on light sensitivity and visual acuity was much higher following ubiquitous retinal ganglion cell expression than that of the strategy targeting ON-type bipolar cells. Our study suggests that, at least based on currently available gene delivery techniques, the expression of genetically encoded light sensors in retinal ganglion cells is likely a practical and advantageous strategy for optogenetic vision restoration.
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31
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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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32
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Empowering Retinal Gene Therapy with a Specific Promoter for Human Rod and Cone ON-Bipolar Cells. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:505-519. [PMID: 32258214 PMCID: PMC7114634 DOI: 10.1016/j.omtm.2020.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/09/2020] [Indexed: 12/31/2022]
Abstract
Optogenetic gene therapy holds promise to restore high-quality vision in blind patients and recently reached clinical trials. Although the ON-bipolar cells, the first retinal interneurons, make the most attractive targets for optogenetic vision restoration, they have remained inaccessible to human gene therapy due to the lack of a robust cell-specific promoter. We describe the design and functional evaluation of 770En_454P(hGRM6), a human GRM6 gene-derived, short promoter that drives strong and highly specific expression in both the rod- and cone-type ON-bipolar cells of the human retina. Expression also in cone-type ON-bipolar cells is of importance, since the cone-dominated macula mediates high-acuity vision and is the primary target of gene therapies. 770En_454P(hGRM6)-driven middle-wave opsin expression in ON-bipolar cells achieved lasting restoration of high visual acuity in the rd1 mouse model of late retinal degeneration. The new promoter enables precise manipulation of the inner retinal network and paves the way for clinical application of gene therapies for high-resolution optogenetic vision restoration, raising hopes of significantly improving the life quality of people suffering from blindness.
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33
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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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34
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Jüttner J, Szabo A, Gross-Scherf B, Morikawa RK, Rompani SB, Hantz P, Szikra T, Esposti F, Cowan CS, Bharioke A, Patino-Alvarez CP, Keles Ö, Kusnyerik A, Azoulay T, Hartl D, Krebs AR, Schübeler D, Hajdu RI, Lukats A, Nemeth J, Nagy ZZ, Wu KC, Wu RH, Xiang L, Fang XL, Jin ZB, Goldblum D, Hasler PW, Scholl HPN, Krol J, Roska B. Targeting neuronal and glial cell types with synthetic promoter AAVs in mice, non-human primates and humans. Nat Neurosci 2019; 22:1345-1356. [PMID: 31285614 DOI: 10.1038/s41593-019-0431-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 05/17/2019] [Indexed: 01/20/2023]
Abstract
Targeting genes to specific neuronal or glial cell types is valuable for both understanding and repairing brain circuits. Adeno-associated viruses (AAVs) are frequently used for gene delivery, but targeting expression to specific cell types is an unsolved problem. We created a library of 230 AAVs, each with a different synthetic promoter designed using four independent strategies. We show that a number of these AAVs specifically target expression to neuronal and glial cell types in the mouse and non-human primate retina in vivo and in the human retina in vitro. We demonstrate applications for recording and stimulation, as well as the intersectional and combinatorial labeling of cell types. These resources and approaches allow economic, fast and efficient cell-type targeting in a variety of species, both for fundamental science and for gene therapy.
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Affiliation(s)
- Josephine Jüttner
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Arnold Szabo
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Brigitte Gross-Scherf
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Rei K Morikawa
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Santiago B Rompani
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Epigenetics and Neurobiology Unit, European Molecular Biology Laboratory, Monterotondo, Italy
| | - Peter Hantz
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Tamas Szikra
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Federico Esposti
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Division of Neuroscience, San Raffaele Research Institute, Università Vita-Salute San Raffaele, Milan, Italy
| | - Cameron S Cowan
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Arjun Bharioke
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Claudia P Patino-Alvarez
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Özkan Keles
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Akos Kusnyerik
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | | | - Dominik Hartl
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Arnaud R Krebs
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Dirk Schübeler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Faculty of Science, University of Basel, Basel, Switzerland
| | - Rozina I Hajdu
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Akos Lukats
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Janos Nemeth
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zoltan Z Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Kun-Chao Wu
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Rong-Han Wu
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Lue Xiang
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Xiao-Long Fang
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Zi-Bing Jin
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - David Goldblum
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Pascal W Hasler
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Hendrik P N Scholl
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Jacek Krol
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
| | - Botond Roska
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland.
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35
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Abstract
Inherited retinal degeneration (IRD), a group of rare retinal diseases that primarily lead to the progressive loss of retinal photoreceptor cells, can be inherited in all modes of inheritance: autosomal dominant (AD), autosomal recessive (AR), X-linked (XL), and mitochondrial. Based on the pattern of inheritance of the dystrophy, retinal gene therapy has 2 main strategies. AR, XL, and AD IRDs with haploinsufficiency can be treated by inserting a functional copy of the gene using either viral or nonviral vectors (gene augmentation). Different types of viral vectors and nonviral vectors are used to transfer plasmid DNA both in vitro and in vivo. AD IRDs with gain-of-function mutations or dominant-negative mutations can be treated by disrupting the mutant allele with (and occasionally without) gene augmentation. This review article aims to provide an overview of ocular gene therapy for treating IRDs using gene augmentation with viral or nonviral vectors or gene disruption through different gene-editing tools, especially with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system.
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Affiliation(s)
- Amirmohsen Arbabi
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Amelia Liu
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hossein Ameri
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
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36
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Day TP, Byrne LC, Flannery JG, Schaffer DV. Screening for Neutralizing Antibodies Against Natural and Engineered AAV Capsids in Nonhuman Primate Retinas. Methods Mol Biol 2018; 1715:239-249. [PMID: 29188518 DOI: 10.1007/978-1-4939-7522-8_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
Adeno-associated virus (AAV) has shown promise as a therapeutic gene delivery vector for inherited retinal degenerations in both preclinical disease models and human clinical trials. The retinas of nonhuman primates (NHPs) share many anatomical similarities to humans and are an important model for evaluating AAV gene delivery. Recent evidence has shown that preexisting immunity in the form of neutralizing antibodies (NABs) in NHPs strongly correlates with weak or lack of AAV transduction in the retina when administered intravitreally, work with translational implications. This necessitates prescreening of NHPs before intravitreal delivery of AAV. In this chapter, we describe a method for screening NHP serum for preexisting NABs.
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Affiliation(s)
- Timothy P Day
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Leah C Byrne
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John G Flannery
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Vision Science Graduate Group, School of Optometry, University of California, Berkeley, CA, USA
| | - David V Schaffer
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
- Department of Bioengineering, University of California, Berkeley, CA, USA.
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA.
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37
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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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38
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van Wyk M, Hulliger EC, Girod L, Ebneter A, Kleinlogel S. Present Molecular Limitations of ON-Bipolar Cell Targeted Gene Therapy. Front Neurosci 2017; 11:161. [PMID: 28424574 PMCID: PMC5372788 DOI: 10.3389/fnins.2017.00161] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/13/2017] [Indexed: 11/13/2022] Open
Abstract
Recent studies have demonstrated the safety and efficacy of ocular gene therapy based on adeno-associated viral vectors (AAVs). Accordingly, a surge in promising new gene therapies is entering clinical trials, including the first optogenetic therapy for vision restoration. To date, optogenetic therapies for vision restoration target either the retinal ganglion cells (GCs) or presynaptic ON-bipolar cells (OBCs). Initiating light responses at the level of the OBCs has significant advantages over optogenetic activation of GCs. For example, important neural circuitries in the inner retina, which shape the receptive fields of GCs, remain intact when activating the OBCs. Current drawbacks of AAV-mediated gene therapies targeting OBCs include (1) a low transduction efficiency, (2) off-target expression in unwanted cell populations, and (3) a poor performance in human tissue compared to the murine retina. Here, we examined side-by-side the performance of three state-of-the art AAV capsid variants, AAV7m8, AAVBP2, and AAV7m8(Y444F) in combination with the 4xGRM6-SV40 promoter construct in the healthy and degenerated mouse retina and in human post-mortem retinal explants. We find that (1) the 4xGRM6-SV40 promoter is not OBC specific, (2) that all AAV variants possess broad cellular transduction patterns, with differences between the transduction patterns of capsid variants AAVBP2 and AAV7m8 and, most importantly, (3) that all vectors target OBCs in healthy tissue but not in the degenerated rd1 mouse model, potentially limiting the possibilities for an OBC-targeted optogenetic therapy for vision restoration in the blind.
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Affiliation(s)
- Michiel van Wyk
- Institute of Physiology, University of BernBern, Switzerland
| | | | - Lara Girod
- Institute of Physiology, University of BernBern, Switzerland
| | - Andreas Ebneter
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of BernBern, Switzerland
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39
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Petit L, Punzo C. Gene therapy approaches for the treatment of retinal disorders. DISCOVERY MEDICINE 2016; 22:221-229. [PMID: 27875674 PMCID: PMC5142441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There is an impelling need to develop effective therapeutic strategies for patients with retinal disorders. Gleaning from the large quantity of information gathered over the past two decades on the mechanisms governing degeneration of the retina, it is now possible to devise innovative therapies based on retinal gene transfer. Different gene-based approaches are under active investigation. They include strategies to correct the specific genetic defect in inherited retinal diseases, strategies to delay the onset of blindness independently of the disease-causing mutations, and strategies to reactivate residual cells at late stages of the diseases. In this review, we discuss the status of application of these technologies, outlining the future therapeutic potential for many forms of retinal blinding diseases.
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Affiliation(s)
- Lolita Petit
- Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Claudio Punzo
- Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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40
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Abstract
Over the last few years, huge progress has been made with regard to the understanding of molecular mechanisms underlying the pathogenesis of neurodegenerative diseases of the eye. Such knowledge has led to the development of gene therapy approaches to treat these devastating disorders. Challenges regarding the efficacy and efficiency of therapeutic gene delivery have driven the development of novel therapeutic approaches, which continue to evolve the field of ocular gene therapy. In this review article, we will discuss the evolution of preclinical and clinical strategies that have improved gene therapy in the eye, showing that treatment of vision loss has a bright future.
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Affiliation(s)
- Lolita Petit
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Hemant Khanna
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts.,2 Department of Neurobiology, University of Massachusetts Medical School , Worcester, Massachusetts
| | - Claudio Punzo
- 1 Department of Ophthalmology and Gene Therapy Center, University of Massachusetts Medical School , Worcester, Massachusetts.,2 Department of Neurobiology, University of Massachusetts Medical School , Worcester, Massachusetts
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