1
|
Rodgers J, Hughes S, Lindner M, Allen AE, Ebrahimi AS, Storchi R, Peirson SN, Lucas RJ, Hankins MW. Functional integrity of visual coding following advanced photoreceptor degeneration. Curr Biol 2023; 33:474-486.e5. [PMID: 36630957 DOI: 10.1016/j.cub.2022.12.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 11/01/2022] [Accepted: 12/09/2022] [Indexed: 01/11/2023]
Abstract
Photoreceptor degeneration sufficient to produce severe visual loss often spares the inner retina. This raises hope for vision restoration treatments using optogenetics or electrical stimulation, which generate a replacement light input signal in surviving neurons. The success of these approaches is dependent on the capacity of surviving circuits of the visual system to generate and propagate an appropriate visual code in the face of neuroanatomical remodeling. To determine whether retinally degenerate animals possess this capacity, we generated a transgenic mouse model expressing the optogenetic actuator ReaChR in ON bipolar cells (second-order neurons in the visual projection). After crossing this with the rd1 model of photoreceptor degeneration, we compared ReaChR-derived responses with photoreceptor-driven responses in wild-type (WT) mice at the level of retinal ganglion cells and the visual thalamus. The ReaChR-driven responses in rd1 animals showed low photosensitivity, but in other respects generated a visual code that was very similar to the WT. ReaChR rd1 responses had high trial-to-trial reproducibility and showed sensitivity normalization to code contrast across background intensities. At the single unit level, ReaChR-derived responses exhibited broadly similar variations in response polarity, contrast sensitivity, and temporal frequency tuning as the WT. Units from the WT and ReaChR rd1 mice clustered together when subjected to unsupervised community detection based on stimulus-response properties. Our data reveal an impressive ability for surviving circuitry to recreate a rich visual code following advanced retinal degeneration and are promising for regenerative medicine in the central nervous system.
Collapse
Affiliation(s)
- Jessica Rodgers
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Steven Hughes
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Moritz Lindner
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps University, Deutschhausstr. 1-2, Marburg 35037, Germany
| | - Annette E Allen
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Aghileh S Ebrahimi
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Riccardo Storchi
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Stuart N Peirson
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Robert J Lucas
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK.
| | - Mark W Hankins
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
| |
Collapse
|
2
|
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.
Collapse
|
3
|
de Grip WJ, Ganapathy S. Rhodopsins: An Excitingly Versatile Protein Species for Research, Development and Creative Engineering. Front Chem 2022; 10:879609. [PMID: 35815212 PMCID: PMC9257189 DOI: 10.3389/fchem.2022.879609] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/16/2022] [Indexed: 01/17/2023] Open
Abstract
The first member and eponym of the rhodopsin family was identified in the 1930s as the visual pigment of the rod photoreceptor cell in the animal retina. It was found to be a membrane protein, owing its photosensitivity to the presence of a covalently bound chromophoric group. This group, derived from vitamin A, was appropriately dubbed retinal. In the 1970s a microbial counterpart of this species was discovered in an archaeon, being a membrane protein also harbouring retinal as a chromophore, and named bacteriorhodopsin. Since their discovery a photogenic panorama unfolded, where up to date new members and subspecies with a variety of light-driven functionality have been added to this family. The animal branch, meanwhile categorized as type-2 rhodopsins, turned out to form a large subclass in the superfamily of G protein-coupled receptors and are essential to multiple elements of light-dependent animal sensory physiology. The microbial branch, the type-1 rhodopsins, largely function as light-driven ion pumps or channels, but also contain sensory-active and enzyme-sustaining subspecies. In this review we will follow the development of this exciting membrane protein panorama in a representative number of highlights and will present a prospect of their extraordinary future potential.
Collapse
Affiliation(s)
- Willem J. de Grip
- Leiden Institute of Chemistry, Department of Biophysical Organic Chemistry, Leiden University, Leiden, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Srividya Ganapathy
- Department of Imaging Physics, Delft University of Technology, Netherlands
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
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: 10] [Impact Index Per Article: 5.0] [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.
Collapse
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.
| |
Collapse
|
6
|
Lehtinen K, Nokia MS, Takala H. Red Light Optogenetics in Neuroscience. Front Cell Neurosci 2022; 15:778900. [PMID: 35046775 PMCID: PMC8761848 DOI: 10.3389/fncel.2021.778900] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/02/2021] [Indexed: 12/25/2022] Open
Abstract
Optogenetics, a field concentrating on controlling cellular functions by means of light-activated proteins, has shown tremendous potential in neuroscience. It possesses superior spatiotemporal resolution compared to the surgical, electrical, and pharmacological methods traditionally used in studying brain function. A multitude of optogenetic tools for neuroscience have been created that, for example, enable the control of action potential generation via light-activated ion channels. Other optogenetic proteins have been used in the brain, for example, to control long-term potentiation or to ablate specific subtypes of neurons. In in vivo applications, however, the majority of optogenetic tools are operated with blue, green, or yellow light, which all have limited penetration in biological tissues compared to red light and especially infrared light. This difference is significant, especially considering the size of the rodent brain, a major research model in neuroscience. Our review will focus on the utilization of red light-operated optogenetic tools in neuroscience. We first outline the advantages of red light for in vivo studies. Then we provide a brief overview of the red light-activated optogenetic proteins and systems with a focus on new developments in the field. Finally, we will highlight different tools and applications, which further facilitate the use of red light optogenetics in neuroscience.
Collapse
Affiliation(s)
- Kimmo Lehtinen
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Miriam S. Nokia
- Department of Psychology, University of Jyväskylä, Jyväskylä, Finland
- Centre for Interdisciplinary Brain Research, University of Jyväskylä, Jyväskylä, Finland
| | - Heikki Takala
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|