Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells

Significance We restored visual function to animal models of human blindness using a chemical compound that photosensitizes a mammalian ion channel. Virus-mediated expression of this light sensor in surviving retinal cells of blind mice restored light responses in vitro, reanimated innate light avoidance, and enabled learned visually guided behavior. The treatment also restored light responses to the retina of blind dogs. Patients that might benefit from this treatment would need to have intact ganglion cell and nerve fiber layers. In general, these are patients diagnosed with retinitis pigmentosa and some forms of Leber congenital amaurosis. Patients diagnosed with other types of blindness, for example, age-related macular degeneration or diabetic retinopathy, would not be candidates for this treatment. Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0460). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0460 was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0460 was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0460 in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0460 in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0460 was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation.

[1]  E. Isacoff,et al.  Photoswitching of cell surface receptors using tethered ligands. , 2014, Methods in molecular biology.

[2]  Jean Bennett,et al.  Efficient transduction and optogenetic stimulation of retinal bipolar cells by a synthetic adeno-associated virus capsid and promoter , 2014, EMBO molecular medicine.

[3]  José-Alain Sahel,et al.  Rod-Derived Cone Viability Factor for Treating Blinding Diseases: From Clinic to Redox Signaling , 2010, Science Translational Medicine.

[4]  Jessy D. Dorn,et al.  Interim results from the international trial of Second Sight's visual prosthesis. , 2012, Ophthalmology.

[5]  Dirk Trauner,et al.  A red-shifted, fast-relaxing azobenzene photoswitch for visible light control of an ionotropic glutamate receptor. , 2013, Journal of the American Chemical Society.

[6]  W. Hauswirth,et al.  Novel properties of tyrosine-mutant AAV2 vectors in the mouse retina. , 2011, Molecular therapy : the journal of the American Society of Gene Therapy.

[7]  Lloyd H. Michael,et al.  The Guide for the Care and Use of Laboratory Animals. , 2016, ILAR journal.

[8]  Alfred Stett,et al.  Subretinal electronic chips allow blind patients to read letters and combine them to words , 2010, Proceedings of the Royal Society B: Biological Sciences.

[9]  Karl Deisseroth,et al.  Genetic Reactivation of Cone Photoreceptors Restores Visual Responses in Retinitis Pigmentosa , 2010, Science.

[10]  G. Aguirre,et al.  Retinal degenerations in the dog. II. Development of the retina in rod-cone dysplasia. , 1980, Experimental eye research.

[11]  Eberhart Zrenner,et al.  Photoreceptor Cell Death Mechanisms in Inherited Retinal Degeneration , 2008, Molecular Neurobiology.

[12]  A. Schier,et al.  Optical Control of Metabotropic Glutamate Receptors , 2013, Nature Neuroscience.

[13]  S. Fried,et al.  Differential responses to high-frequency electrical stimulation in ON and OFF retinal ganglion cells , 2014, Journal of neural engineering.

[14]  Dirk Trauner,et al.  LiGluR restores visual responses in rodent models of inherited blindness. , 2011, Molecular therapy : the journal of the American Society of Gene Therapy.

[15]  Krista I Kinard,et al.  Neural reprogramming in retinal degeneration. , 2007, Investigative ophthalmology & visual science.

[16]  M. Hascöet,et al.  The mouse light/dark box test. , 2003, European journal of pharmacology.

[17]  R. Hurwitz,et al.  Irish setter dogs affected with rod/cone dysplasia contain a nonsense mutation in the rod cGMP phosphodiesterase beta-subunit gene. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[18]  E. Strettoi,et al.  Retinal Ganglion Cells Survive and Maintain Normal Dendritic Morphology in a Mouse Model of Inherited Photoreceptor Degeneration , 2008, The Journal of Neuroscience.

[19]  Tomomitsu Miyoshi,et al.  Specific deficit of the ON response in visual transmission by targeted disruption of the mGIuR6 gene , 1995, Cell.

[20]  E. Isacoff,et al.  Allosteric control of an ionotropic glutamate receptor with an optical switch , 2006, Nature chemical biology.

[21]  K. Ray,et al.  Cosegregation of codon 807 mutation of the canine rod cGMP phosphodiesterase beta gene and rcd1. , 1994, Investigative ophthalmology & visual science.

[22]  Chethan Pandarinath,et al.  Retinal prosthetic strategy with the capacity to restore normal vision , 2012, Proceedings of the National Academy of Sciences.

[23]  E. Isacoff,et al.  Mechanisms of photoswitch conjugation and light activation of an ionotropic glutamate receptor , 2007, Proceedings of the National Academy of Sciences.

[24]  Ehud Y. Isacoff,et al.  Optical Control of Endogenous Proteins with a Photoswitchable Conditional Subunit Reveals a Role for TREK1 in GABAB Signaling , 2012, Neuron.

[25]  J. Kong,et al.  Diversity of ganglion cells in the mouse retina: Unsupervised morphological classification and its limits , 2005, The Journal of comparative neurology.

[26]  Alexander Sumaroka,et al.  Canine Retina Has a Primate Fovea-Like Bouquet of Cone Photoreceptors Which Is Affected by Inherited Macular Degenerations , 2014, PloS one.

[27]  Volker Busskamp,et al.  Optogenetic approaches to restoring visual function in retinitis pigmentosa , 2011, Current Opinion in Neurobiology.

[28]  K. Mathieson,et al.  Cortical responses elicited by photovoltaic subretinal prostheses exhibit similarities to visually evoked potentials , 2013, Nature Communications.

[29]  P. Greengard,et al.  Differential expression of synapsins I and II among rat retinal synapses , 1992, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[30]  Richard H. Masland,et al.  The Diversity of Ganglion Cells in a Mammalian Retina , 2002, The Journal of Neuroscience.

[31]  R. E. Brown,et al.  Visual detection, pattern discrimination and visual acuity in 14 strains of mice , 2006, Genes, brain, and behavior.

[32]  J. Sahel,et al.  La rétinopathie pigmentaire : restauration visuelle par thérapie optogénétique , 2013 .

[33]  Dirk Trauner,et al.  Photochemical Restoration of Visual Responses in Blind Mice , 2012, Neuron.

[34]  Kelly Shintani,et al.  Review and update: current treatment trends for patients with retinitis pigmentosa. , 2009, Optometry.

[35]  Edward S Boyden,et al.  Virally delivered channelrhodopsin-2 safely and effectively restores visual function in multiple mouse models of blindness. , 2011, Molecular therapy : the journal of the American Society of Gene Therapy.

[36]  B. Jones,et al.  Neural remodeling in retinal degeneration , 2003, Progress in Retinal and Eye Research.

[37]  W. Beltran.  The use of canine models of inherited retinal degeneration to test novel therapeutic approaches. , 2009, Veterinary ophthalmology.

[38]  E. Isacoff,et al.  Tethered ligands reveal glutamate receptor desensitization depends on subunit occupancy , 2014, Nature chemical biology.

[39]  R. Masland,et al.  Restoration of visual function in retinal degeneration mice by ectopic expression of melanopsin , 2008, Proceedings of the National Academy of Sciences.

[40]  Martin Biel,et al.  Synaptic Plasticity in CNGA3−/− Mice: Cone Bipolar Cells React on the Missing Cone Input and Form Ectopic Synapses with Rods , 2006, The Journal of Neuroscience.

[41]  Botond Roska,et al.  Parallel processing in retinal ganglion cells: how integration of space-time patterns of excitation and inhibition form the spiking output. , 2006, Journal of neurophysiology.

[42]  H. Wässle,et al.  Cone Contacts, Mosaics, and Territories of Bipolar Cells in the Mouse Retina , 2009, The Journal of Neuroscience.

[43]  Dirk Trauner,et al.  Restoring Visual Function to Blind Mice with a Photoswitch that Exploits Electrophysiological Remodeling of Retinal Ganglion Cells , 2014, Neuron.

[44]  J. Grieger,et al.  Production and characterization of adeno-associated viral vectors , 2006, Nature Protocols.

[45]  Konrad Lehmann,et al.  Visual Function in Mice with Photoreceptor Degeneration and Transgenic Expression of Channelrhodopsin 2 in Ganglion Cells , 2010, The Journal of Neuroscience.

[46]  A. Dizhoor,et al.  Ectopic Expression of a Microbial-Type Rhodopsin Restores Visual Responses in Mice with Photoreceptor Degeneration , 2006, Neuron.

[47]  B. Roska,et al.  Optogenetic therapy for retinitis pigmentosa , 2011, Gene Therapy.

[48]  Dirk Trauner,et al.  Optochemical control of genetically engineered neuronal nicotinic acetylcholine receptors. , 2012, Nature chemistry.

[49]  F. Werblin,et al.  Spatiotemporal patterns at the retinal output. , 1998, Journal of neurophysiology.

[50]  Douglas S Kim,et al.  Light-activated channels targeted to ON bipolar cells restore visual function in retinal degeneration , 2008, Nature Neuroscience.

[51]  Enrica Strettoi,et al.  Retinal organization in the retinal degeneration 10 (rd10) mutant mouse: A morphological and ERG study , 2007, The Journal of comparative neurology.