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Ham Y, Mehta H, Kang-Mieler J, Mieler WF, Chang A. Novel Drug Delivery Methods and Approaches for the Treatment of Retinal Diseases. Asia Pac J Ophthalmol (Phila) 2023; 12:402-413. [PMID: 37523432 DOI: 10.1097/apo.0000000000000623] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/30/2023] [Indexed: 08/02/2023] Open
Abstract
This review discusses emerging approaches to ocular drug delivery for retinal diseases. Intravitreal injections have proven to be an effective, safe, and commonly used drug delivery method. However, the optimal management of chronic retinal diseases requires frequent intravitreal injections over extended periods of time. Although this can be achieved in a clinical trial environment, it is difficult to replicate in routine clinical practice. In addition, frequent treatment increases the risk of complications, incurs more costs, and increases the treatment burden for patients and caregivers. Given the aging global population and diabetes pandemic, there is an urgent need for drug delivery methods that support more durable retinal therapy while maintaining the efficacy and safety of currently available intravitreal therapies. Several innovative drug delivery methods are currently being investigated. These include sustained-release implants and depots using prodrugs, microparticles, and hydrogels, surgically implanted reservoirs, gene therapy via submacular injections or suprachoroidal injections, as well as topical and systemic therapies.
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Affiliation(s)
- Yeji Ham
- Sydney Retina Clinic, Sydney, Australia
| | - Hemal Mehta
- Sydney Retina Clinic, Sydney, Australia
- Save Sight Registries, The University of Sydney, Sydney, Australia
- Strathfield Retina Clinic, Sydney, Australia
| | - Jennifer Kang-Mieler
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ
| | | | - Andrew Chang
- Sydney Retina Clinic, Sydney Eye Hospital, The University of Sydney, Sydney, Australia
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2
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Itkonen J, Annala A, Tavakoli S, Arango-Gonzalez B, Ueffing M, Toropainen E, Ruponen M, Casteleijn MG, Urtti A. Characterization, Stability, and in Vivo Efficacy Studies of Recombinant Human CNTF and Its Permeation into the Neural Retina in ex Vivo Organotypic Retinal Explant Culture Models. Pharmaceutics 2020; 12:pharmaceutics12070611. [PMID: 32629980 PMCID: PMC7408322 DOI: 10.3390/pharmaceutics12070611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 12/17/2022] Open
Abstract
Ciliary neurotrophic factor (CNTF) is one of the most studied neuroprotective agents with acknowledged potential in treating diseases of the posterior eye segment. Although its efficacy and mechanisms of action in the retina have been studied extensively, it is still not comprehensively understood which retinal cells mediate the therapeutic effects of CNTF. As with therapeutic proteins in general, it is poorly elucidated whether exogenous CNTF administered into the vitreous can enter and distribute into the retina and hence reach potentially responsive target cells. Here, we have characterized our purified recombinant human CNTF (rhCNTF), studied the protein’s in vitro bioactivity in a cell-based assay, and evaluated the thermodynamic and oligomeric status of the protein during storage. Biological activity of rhCNTF was further evaluated in vivo in an animal model of retinal degeneration. The retinal penetration and distribution of rhCNTF after 24 h was studied utilizing two ex vivo retina models. Based on our characterization findings, our rhCNTF is correctly folded and biologically active. Moreover, based on initial screening and subsequent follow-up, we identified two buffers in which rhCNTF retains its stability during storage. Whereas rhCNTF did not show photoreceptor preservative effect or improve the function of photoreceptors in vivo, this could possibly be due to the used disease model or the short duration of action with a single intravitreal injection of rhCNTF. On the other hand, the lack of in vivo efficacy was shown to not be due to distribution limitations; permeation into the retina was observed in both retinal explant models as in 24 h rhCNTF penetrated the inner limiting membrane, and being mostly observed in the ganglion cell layer, distributed to different layers of the neural retina. As rhCNTF can reach deeper retinal layers, in general, having direct effects on resident CNTF-responsive target cells is plausible.
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Affiliation(s)
- Jaakko Itkonen
- Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E, 00790 Helsinki, Finland; (S.T.); (M.G.C.)
- Correspondence: (J.I.); (A.U.)
| | - Ada Annala
- School of Pharmacy, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland; (A.A.); (E.T.); (M.R.)
- Utrecht Institute for Pharmaceutical Science, Utrecht University, David de Wiedgebouw, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Shirin Tavakoli
- Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E, 00790 Helsinki, Finland; (S.T.); (M.G.C.)
| | - Blanca Arango-Gonzalez
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Strasse 7, D-72076 Tübingen, Germany; (B.A.-G.); (M.U.)
| | - Marius Ueffing
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Strasse 7, D-72076 Tübingen, Germany; (B.A.-G.); (M.U.)
| | - Elisa Toropainen
- School of Pharmacy, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland; (A.A.); (E.T.); (M.R.)
| | - Marika Ruponen
- School of Pharmacy, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland; (A.A.); (E.T.); (M.R.)
| | - Marco G. Casteleijn
- Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E, 00790 Helsinki, Finland; (S.T.); (M.G.C.)
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, Espoo, P.O. Box 1000, FI-02044 VTT, Finland
| | - Arto Urtti
- Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E, 00790 Helsinki, Finland; (S.T.); (M.G.C.)
- School of Pharmacy, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland; (A.A.); (E.T.); (M.R.)
- Laboratory of Biohybrid Technologies, Institute of Chemistry, St. Petersburg State University, Universitetskii pr. 26, Peterhoff, 198504 St. Petersburg, Russia
- Correspondence: (J.I.); (A.U.)
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3
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Dufour VL, Yu Y, Pan W, Ying GS, Aguirre GD, Beltran WA. In-vivo longitudinal changes in thickness of the postnatal canine retina. Exp Eye Res 2020; 192:107926. [PMID: 31931002 DOI: 10.1016/j.exer.2020.107926] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 01/03/2020] [Accepted: 01/06/2020] [Indexed: 11/29/2022]
Abstract
The objectives of the present work were to assess by spectral domain optical coherence tomography (OCT) the changes in thickness of the outer nuclear layer (ONL), the ONL + photoreceptor inner segment (IS), and the retinal thickness, as a function of age in the normal canine retina. OCT retinal scans extending from the edge of the optic nerve head (ONH) along the superior and inferior meridians were captured in both eyes of 17 normal dogs at age ranging from 4 to 119 weeks. The different parameters along the superior and the inferior regions were determined following manual segmentation using the Heidelberg Eye Explorer software. Changes in thickness with age were modeled using one-phase exponential decay models. In vivo OCT imaging results showed no interocular statistically significant differences in ONL, ONL + IS, and retinal thickness at any age. All three parameters were however found to be statistically significantly thicker in the superior vs inferior retina. A rapid thinning of the three layers occurs in both the superior and inferior retina between 4 and 12 weeks of age, before reaching a plateau at around 20 weeks of age. In conclusion, the ONL, ONL + IS, and retinal thickness of the normal canine retina decrease significantly during the first three postnatal months, and is likely attributed to an overall increase in the eye volume and tangential dispersion of the photoreceptor since early photoreceptor developmental cell death is very limited at that age. Establishment of the natural history of ONL, ONL + IS, and retinal thinning will allow a more accurate assessment of the progression of a retinal degenerative condition as well as facilitate the detection of positive rescue effect of novel retinal therapies evaluated in this large animal model.
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Affiliation(s)
- Valérie L Dufour
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yinxi Yu
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Wei Pan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gui-Shuang Ying
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gustavo D Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - William A Beltran
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Cehajic Kapetanovic J, McClements ME, Martinez-Fernandez de la Camara C, MacLaren RE. Molecular Strategies for RPGR Gene Therapy. Genes (Basel) 2019; 10:genes10090674. [PMID: 31487940 PMCID: PMC6770968 DOI: 10.3390/genes10090674] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/27/2019] [Accepted: 09/01/2019] [Indexed: 11/16/2022] Open
Abstract
Mutations affecting the Retinitis Pigmentosa GTPase Regulator (RPGR) gene are the commonest cause of X-linked and recessive retinitis pigmentosa (RP), accounting for 10%-20% of all cases of RP. The phenotype is one of the most severe amongst all causes of RP, characteristic for its early onset and rapid progression to blindness in young people. At present there is no cure for RPGR-related retinal disease. Recently, however, there have been important advances in RPGR research from bench to bedside that increased our understanding of RPGR function and led to the development of potential therapies, including the progress of adeno-associated viral (AAV)-mediated gene replacement therapy into clinical trials. This manuscript discusses the advances in molecular research, which have connected the RPGR protein with an important post-translational modification, known as glutamylation, that is essential for its optimal function as a key regulator of photoreceptor ciliary transport. In addition, we review key pre-clinical research that addressed challenges encountered during development of therapeutic vectors caused by high infidelity of the RPGR genomic sequence. Finally, we discuss the structure of three current phase I/II clinical trials based on three AAV vectors and RPGR sequences and link the rationale behind the use of the different vectors back to the bench research that led to their development.
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Affiliation(s)
- Jasmina Cehajic Kapetanovic
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK. '
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK. '
| | | | - Cristina Martinez-Fernandez de la Camara
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
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5
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Li S, Sato K, Gordon WC, Sendtner M, Bazan NG, Jin M. Ciliary neurotrophic factor (CNTF) protects retinal cone and rod photoreceptors by suppressing excessive formation of the visual pigments. J Biol Chem 2018; 293:15256-15268. [PMID: 30115683 DOI: 10.1074/jbc.ra118.004008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/15/2018] [Indexed: 12/25/2022] Open
Abstract
The retinal pigment epithelium (RPE)-dependent visual cycle provides 11-cis-retinal to opsins in the photoreceptor outer segments to generate functional visual pigments that initiate phototransduction in response to light stimuli. Both RPE65 isomerase of the visual cycle and the rhodopsin visual pigment have recently been identified as critical players in mediating light-induced retinal degeneration. These findings suggest that the expression and function of RPE65 and rhodopsin need to be coordinately controlled to sustain normal vision and to protect the retina from photodamage. However, the mechanism controlling the development of the retinal visual system remains poorly understood. Here, we show that deficiency in ciliary neurotrophic factor (CNTF) up-regulates the levels of rod and cone opsins accompanied by an increase in the thickness of the outer nuclear layers and the lengths of cone and rod outer segments in the mouse retina. Moreover, retinoid isomerase activity, expression levels of RPE65 and lecithin:retinol acyltransferase (LRAT), which synthesizes the RPE65 substrate, were also significantly increased in the Cntf -/- RPE. Rod a-wave and cone b-wave amplitudes of electroretinograms were increased in Cntf -/- mice, but rod b-wave amplitudes were unchanged compared with those in WT mice. Up-regulated RPE65 and LRAT levels accelerated both the visual cycle rate and recovery rate of rod light sensitivity in Cntf -/- mice. Of note, rods and cones in Cntf -/- mice exhibited hypersusceptibility to light-induced degeneration. These results indicate that CNTF is a common extracellular factor that prevents excessive production of opsins, the photoreceptor outer segments, and 11-cis-retinal to protect rods and cones from photodamage.
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Affiliation(s)
- Songhua Li
- From the Neuroscience Center of Excellence and
| | - Kota Sato
- From the Neuroscience Center of Excellence and
| | - William C Gordon
- From the Neuroscience Center of Excellence and.,Department of Ophthalmology, Louisiana State University School of Medicine, New Orleans, Louisiana 70112 and
| | - Michael Sendtner
- the Institute of Clinical Neurobiology, University Hospital Würzburg, D-97078 Würzburg, Germany
| | - Nicolas G Bazan
- From the Neuroscience Center of Excellence and.,Department of Ophthalmology, Louisiana State University School of Medicine, New Orleans, Louisiana 70112 and
| | - Minghao Jin
- From the Neuroscience Center of Excellence and .,Department of Ophthalmology, Louisiana State University School of Medicine, New Orleans, Louisiana 70112 and
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6
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Ghasemi M, Alizadeh E, Saei Arezoumand K, Fallahi Motlagh B, Zarghami N. Ciliary neurotrophic factor (CNTF) delivery to retina: an overview of current research advancements. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2017; 46:1694-1707. [PMID: 29065723 DOI: 10.1080/21691401.2017.1391820] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The intraocular administration of the ciliary neurotrophic factor (CNTF) has been found to attenuate the photoreceptor degeneration and preserve retinal functions in the animal research models of the inherited or induced retinal disease. Studies with the aim of CNTF transfer to the posterior segment inside the eye have been directed to determine the best method for its administration. An ideal delivery method would overcome the eye drug elimination mechanisms or barriers and provide the sustained release of the CNTF into retina in the safest fashion with the minimum harm to the quality of life. This review focuses on the present state of CNTF delivery to retina, also provides an overview of available technologies and their challenges.
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Affiliation(s)
- Maryam Ghasemi
- a The Umbilical Cord Stem Cell Research Center (UCSRC) , Tabriz University of Medical Sciences , Tabriz , Iran.,b Department of Medical Biotechnology, Faculty of Advanced Medical Sciences , Tabriz University of Medical Sciences , Tabriz , Iran
| | - Effat Alizadeh
- a The Umbilical Cord Stem Cell Research Center (UCSRC) , Tabriz University of Medical Sciences , Tabriz , Iran.,b Department of Medical Biotechnology, Faculty of Advanced Medical Sciences , Tabriz University of Medical Sciences , Tabriz , Iran
| | - Khatereh Saei Arezoumand
- b Department of Medical Biotechnology, Faculty of Advanced Medical Sciences , Tabriz University of Medical Sciences , Tabriz , Iran
| | | | - Nosratollah Zarghami
- a The Umbilical Cord Stem Cell Research Center (UCSRC) , Tabriz University of Medical Sciences , Tabriz , Iran.,b Department of Medical Biotechnology, Faculty of Advanced Medical Sciences , Tabriz University of Medical Sciences , Tabriz , Iran.,d Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine , Tabriz University of Medical Sciences , Tabriz , Iran
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7
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Charng J, Cideciyan AV, Jacobson SG, Sumaroka A, Schwartz SB, Swider M, Roman AJ, Sheplock R, Anand M, Peden MC, Khanna H, Heon E, Wright AF, Swaroop A. Variegated yet non-random rod and cone photoreceptor disease patterns in RPGR-ORF15-associated retinal degeneration. Hum Mol Genet 2016; 25:5444-5459. [PMID: 27798110 PMCID: PMC6078602 DOI: 10.1093/hmg/ddw361] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/16/2016] [Accepted: 10/18/2016] [Indexed: 12/13/2022] Open
Abstract
Mutations in the ORF15 exon of the RPGR gene cause a common form of X-linked retinitis pigmentosa, which often results in severe loss of vision. In dogs and mice, gene augmentation therapy has been shown to arrest the progressive degeneration of rod and cone photoreceptors. However, the distribution of potentially treatable photoreceptors across the human retinas and the rate of degeneration are not known. Here, we have defined structural and functional features of the disease in 70 individuals with ORF15 mutations. We also correlated the features observed in patients with those of three Rpgr-mutant (Rpgr-ko, Rd9, and Rpgr-cko) mice. In patients, there was pronounced macular disease. Across the retina, rod and cone dysfunction showed a range of patterns and a spectrum of severity between individuals, but a high symmetry was observed between eyes of each individual. Genotype was not related to disease expression. In the Rpgr-ko mice, there were intra-retinal differences in rhodopsin and cone opsin trafficking. In Rd9 and Rpgr-cko mice, retinal degeneration showed inter-ocular symmetry. Longitudinal results in patients revealed localized rod and cone dysfunction with progression rates of 0.8 to 1.3 log per decade in sensitivity loss. Relatively retained rod and cone photoreceptors in mid- and far-peripheral temporal-inferior and nasal-inferior visual field regions should be good targets for future localized gene therapies in patients.
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Affiliation(s)
- Jason Charng
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Artur V. Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Samuel G. Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Sharon B. Schwartz
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Malgorzata Swider
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Alejandro J. Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Rebecca Sheplock
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA, USA
| | - Manisha Anand
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, MA, USA
| | - Marc C. Peden
- Retina Associates of Florida, Tampa, Florida, FL, USA
| | - Hemant Khanna
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, MA, USA
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Alan F. Wright
- MRC Human Genetics Unit, MRC IGMM, University of Edinburgh, Edinburgh, Scotland, UK
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, MD, USA
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8
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Jones BW, Pfeiffer RL, Ferrell WD, Watt CB, Marmor M, Marc RE. Retinal remodeling in human retinitis pigmentosa. Exp Eye Res 2016; 150:149-65. [PMID: 27020758 DOI: 10.1016/j.exer.2016.03.018] [Citation(s) in RCA: 216] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 02/23/2016] [Accepted: 03/18/2016] [Indexed: 12/11/2022]
Abstract
Retinitis Pigmentosa (RP) in the human is a progressive, currently irreversible neural degenerative disease usually caused by gene defects that disrupt the function or architecture of the photoreceptors. While RP can initially be a disease of photoreceptors, there is increasing evidence that the inner retina becomes progressively disorganized as the outer retina degenerates. These alterations have been extensively described in animal models, but remodeling in humans has not been as well characterized. This study, using computational molecular phenotyping (CMP) seeks to advance our understanding of the retinal remodeling process in humans. We describe cone mediated preservation of overall topology, retinal reprogramming in the earliest stages of the disease in retinal bipolar cells, and alterations in both small molecule and protein signatures of neurons and glia. Furthermore, while Müller glia appear to be some of the last cells left in the degenerate retina, they are also one of the first cell classes in the neural retina to respond to stress which may reveal mechanisms related to remodeling and cell death in other retinal cell classes. Also fundamentally important is the finding that retinal network topologies are altered. Our results suggest interventions that presume substantial preservation of the neural retina will likely fail in late stages of the disease. Even early intervention offers no guarantee that the interventions will be immune to progressive remodeling. Fundamental work in the biology and mechanisms of disease progression are needed to support vision rescue strategies.
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Affiliation(s)
- B W Jones
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA.
| | - R L Pfeiffer
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
| | - W D Ferrell
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
| | - C B Watt
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
| | - M Marmor
- Dept. Ophthalmology, Stanford University, USA
| | - R E Marc
- Dept. Ophthalmology, Moran Eye Center, University of Utah, USA
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9
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Palanova A. The genetics of inherited retinal disorders in dogs: implications for diagnosis and management. VETERINARY MEDICINE-RESEARCH AND REPORTS 2016; 7:41-51. [PMID: 30050836 PMCID: PMC6042528 DOI: 10.2147/vmrr.s63537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Dogs are affected by many hereditary diseases just as humans are. One group of these diseases comprises of retinal disorders, which are a growing problem in canine breeding. These disorders are heterogeneous, with diverse causative mutations and modes of inheritance. Some affect only one breed, while others may affect many breeds; some breeds are affected by only one disease, while others can be affected by two or more. Dog breeders should take into account the presence of any deleterious alleles when choosing parents for the next generation.
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Affiliation(s)
- Anna Palanova
- Department of Tumor Biology, Institute of Animal Physiology and Genetics, v. v. i., Academy of Sciences of the Czech Republic, Libechov, Czech Republic,
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10
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Lipinski DM, Barnard AR, Singh MS, Martin C, Lee EJ, Davies WIL, MacLaren RE. CNTF Gene Therapy Confers Lifelong Neuroprotection in a Mouse Model of Human Retinitis Pigmentosa. Mol Ther 2015; 23:1308-1319. [PMID: 25896245 DOI: 10.1038/mt.2015.68] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 02/28/2015] [Indexed: 12/12/2022] Open
Abstract
The long-term outcome of neuroprotection as a therapeutic strategy for preventing cell death in neurodegenerative disorders remains unknown, primarily due to slow disease progression and the inherent difficulty of assessing neuronal survival in vivo. Employing a murine model of retinal disease, we demonstrate that ciliary neurotrophic factor (CNTF) confers life-long protection against photoreceptor degeneration. Repetitive retinal imaging allowed the survival of intrinsically fluorescent cone photoreceptors to be quantified in vivo. Imaging of the visual cortex and assessment of visually-evoked behavioral responses demonstrated that surviving cones retain function and signal correctly to the brain. The mechanisms underlying CNTF-mediated neuroprotection were explored through transcriptome analysis, revealing widespread upregulation of proteolysis inhibitors, which may prevent cellular/extracellular matrix degradation and complement activation in neurodegenerative diseases. These findings provide insights into potential novel therapeutic avenues for diseases such as retinitis pigmentosa and amyotrophic lateral sclerosis, for which CNTF has been evaluated unsuccessfully in clinical trials.
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Affiliation(s)
- Daniel M Lipinski
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; Oxford Biomedical Research Centre, University of Oxford, Oxford, UK; Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Mandeep S Singh
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Chris Martin
- Department of Psychology, The University of Sheffield, Sheffield, UK
| | - Edward J Lee
- Moorfields Eye Hospital & UCL NIHR Biomedical Research Centre for Ophthalmology, London, UK
| | - Wayne I L Davies
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; School of Animal Biology and University of Western Australia Oceans Institute, University of Western Australia, Perth, Australia
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; Oxford Biomedical Research Centre, University of Oxford, Oxford, UK; Moorfields Eye Hospital & UCL NIHR Biomedical Research Centre for Ophthalmology, London, UK.
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11
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Localizing the RPGR protein along the cilium: a new method to determine efficacies to treat RPGR mutations. Gene Ther 2015; 22:413-20. [PMID: 25630948 DOI: 10.1038/gt.2014.128] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 12/16/2014] [Accepted: 12/19/2014] [Indexed: 01/18/2023]
Abstract
Retinal dystrophies constitute a group of clinically and genetically heterogeneous diseases that cause visual impairment. As treatments are not readily available, readout assays performed in patient-derived cells can aid in the development and comparative analysis of therapeutic approaches. We describe a new method with which the localization of the retinitis pigmentosa GTPase regulator (RPGR) protein along the cilium can be used as a measure for treatment efficacy. In a patient-derived fibroblast cell line, we found that the RPGR protein is mislocalized along the ciliary axoneme. The patient carried a point mutation that leads to skipping of RPGR exon 10. We confirmed that this skipping is causative for the impaired localization of RPGR using a U7 small nuclear RNA (U7snRNA)-based antisense approach in control cells. Treatment of the patient-derived fibroblasts with therapeutic U1snRNA significantly corrected the proteins' mislocalization. In this proof of principle study, we show that detecting the RPGR protein along the cilium provides a reliable and quantifiable readout assay to evaluate the efficacy of therapies intended to correct or silence RPGR gene mutations. This method opens the possibility to compare different therapeutic agents, and thus facilitate the identification of treatment options for the clinically and molecularly complex RPGR-associated diseases.
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12
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Beltran WA, Cideciyan AV, Lewin AS, Hauswirth WW, Jacobson SG, Aguirre GD. Gene augmentation for X-linked retinitis pigmentosa caused by mutations in RPGR. Cold Spring Harb Perspect Med 2014; 5:a017392. [PMID: 25301933 DOI: 10.1101/cshperspect.a017392] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
X-linked retinitis pigmentosa (XLRP) caused by mutations in the RPGR gene is a severe and early onset form of retinal degeneration, and no treatment is currently available. Recent evidence in two clinically relevant canine models shows that adeno-associated viral (AAV)-mediated RPGR gene transfer to rods and cones can prevent disease onset and rescue photoreceptors at early- and mid-stages of degeneration. There is thus a strong incentive for conducting long-term, preclinical efficacy and safety studies, while concomitantly pursuing the detailed phenotypic characterization of XLRP disease in patients that may benefit from such corrective therapy.
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Affiliation(s)
- William A Beltran
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Alfred S Lewin
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, Florida 32610
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida, Gainesville, Florida 32610
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Gustavo D Aguirre
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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Sadigh S, Luo X, Cideciyan AV, Sumaroka A, Boxley SL, Hall LM, Sheplock R, Feuer WJ, Stambolian DS, Jacobson SG. Drusen and photoreceptor abnormalities in African-Americans with intermediate non-neovascular age-related macular degeneration. Curr Eye Res 2014; 40:398-406. [PMID: 24912073 DOI: 10.3109/02713683.2014.925934] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE/AIM To investigate the relationship of drusen and photoreceptor abnormalities in African-American (AA) patients with intermediate non-neovascular age-related macular degeneration (AMD). MATERIALS AND METHODS AA patients with intermediate AMD (n = 11; age 52-77 years) were studied with spectral-domain optical coherence tomography. Macular location and characteristics of large drusen (≥125 µm) were determined. Thickness of photoreceptor laminae was quantified overlying drusen and in other macular regions. A patient with advanced AMD (age 87) was included to illustrate the disease spectrum. RESULTS In this AA patient cohort, the spectrum of changes known to occur in AMD, including large drusen, sub-retinal drusenoid deposits and geographic atrophy, were identified. In intermediate AMD eyes (n = 17), there were 183 large drusen, the majority of which were pericentral in location. Overlying the drusen there was significant thinning of the photoreceptor outer nuclear layer (termed ONL(+)) as well as the inner and outer segments (IS + OS). The reductions in IS + OS thickness were directly related to ONL(+) thickness. In a fraction (∼8%) of paradrusen locations with normal lamination sampled within ∼280 µm of peak drusen height, ONL(+) was significantly thickened compared to age and retinal-location-matched normal values. Topographical maps of the macula confirmed ONL thickening in regions neighboring and distant to large drusen. CONCLUSIONS We confirm there is a pericentral distribution of drusen across AA-AMD maculae rather than the central localization in Caucasian AMD. Reductions in the photoreceptor laminae overlying drusen are evident. ONL(+) thickening in some macular areas of AA-AMD eyes may be an early phenotypic marker for photoreceptor stress.
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Affiliation(s)
- Sam Sadigh
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA , USA
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Transient photoreceptor deconstruction by CNTF enhances rAAV-mediated cone functional rescue in late stage CNGB3-achromatopsia. Mol Ther 2013; 21:1131-41. [PMID: 23568263 DOI: 10.1038/mt.2013.50] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Achromatopsia is a genetic disorder of cones, and one of the most common forms is a channelopathy caused by mutations in the β-subunit, CNGB3, of the cone cyclic nucleotide-gated (CNG) channel. Recombinant adeno-associated virus of serotype 5 (rAAV5)-mediated gene transfer of human CNGB3 cDNA to mutant dog cones results in functional and structural rescue in dogs <0.5 years of age, but treatment is minimally effective in dogs >1 year. We now test a new therapeutic concept by combining gene therapy with the administration of ciliary neurotrophic factor (CNTF). Intravitreal CNTF causes transient dedifferentiation of photoreceptors, a process called deconstruction, whereby visual cells become immature with short outer segments, and decreased retinal function and gene expression that subsequently return to normal. Cone function was successfully rescued in all mutant dogs treated between 14 and 42 months of age with this strategy. CNTF-mediated deconstruction and regeneration of the photoreceptor outer segments prepares the mutant cones optimally for gene augmentation therapy.
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15
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Successful subretinal delivery and monitoring of MicroBeads in mice. PLoS One 2013; 8:e55173. [PMID: 23383096 PMCID: PMC3557268 DOI: 10.1371/journal.pone.0055173] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 12/19/2012] [Indexed: 11/19/2022] Open
Abstract
Background To monitor viability of implanted genetically engineered and microencapsulated human stem cells (MicroBeads) in the mouse eye, and to study the impact of the beads and/or xenogenic cells on retinal integrity. Methodology/Principal Findings MicroBeads were implanted into the subretinal space of SV126 wild type mice using an ab externo approach. Viability of microencapsulated cells was monitored by noninvasive retinal imaging (Spectralis™ HRA+OCT). Retinal integrity was also assessed with retinal imaging and upon the end of the study by light and electron microscopy. The implanted GFP-marked cells encapsulated in subretinal MicroBeads remained viable over a period of up to 4 months. Retinal integrity and viability appeared unaltered apart from the focal damage due to the surgical implantation, GFAP upregulation, and opsin mistargeting in the immediate surrounding tissue. Conclusions/Significance The accessibility for routine surgery and its immune privileged state make the eye an ideal target for release system implants for therapeutic substances, including neurotrophic and anti-angiogenic compounds or protein based biosimilars. Microencapsulated human stem cells (MicroBeads) promise to overcome limitations inherent with single factor release systems, as they are able to produce physiologic combinations of bioactive compounds.
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16
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Wen R, Tao W, Li Y, Sieving PA. CNTF and retina. Prog Retin Eye Res 2011; 31:136-51. [PMID: 22182585 DOI: 10.1016/j.preteyeres.2011.11.005] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 10/29/2011] [Accepted: 11/17/2011] [Indexed: 11/15/2022]
Abstract
Ciliary neurotrophic factor (CNTF) is one of the most studied neurotrophic factors for neuroprotection of the retina. A large body of evidence demonstrates that CNTF promotes rod photoreceptor survival in almost all animal models. Recent studies indicate that CNTF also promotes cone photoreceptor survival and cone outer segment regeneration in the degenerating retina and improves cone function in dogs with congenital achromotopsia. In addition, CNTF is a neuroprotective factor and an axogenesis factor for retinal ganglion cells (RGCs). This review focuses on the effects of exogenous CNTF on photoreceptors and RGCs in the mammalian retina and the potential clinical application of CNTF for retinal degenerative diseases.
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Affiliation(s)
- Rong Wen
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
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17
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Jones BW, Kondo M, Terasaki H, Watt CB, Rapp K, Anderson J, Lin Y, Shaw MV, Yang JH, Marc RE. Retinal remodeling in the Tg P347L rabbit, a large-eye model of retinal degeneration. J Comp Neurol 2011; 519:2713-33. [PMID: 21681749 DOI: 10.1002/cne.22703] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Retinitis pigmentosa (RP) is an inherited blinding disease characterized by progressive loss of retinal photoreceptors. There are numerous rodent models of retinal degeneration, but most are poor platforms for interventions that will translate into clinical practice. The rabbit possesses a number of desirable qualities for a model of retinal disease including a large eye and an existing and substantial knowledge base in retinal circuitry, anatomy, and ophthalmology. We have analyzed degeneration, remodeling, and reprogramming in a rabbit model of retinal degeneration, expressing a rhodopsin proline 347 to leucine transgene in a TgP347L rabbit as a powerful model to study the pathophysiology and treatment of retinal degeneration. We show that disease progression in the TgP347L rabbit closely tracks human cone-sparing RP, including the cone-associated preservation of bipolar cell signaling and triggering of reprogramming. The relatively fast disease progression makes the TgP347L rabbit an excellent model for gene therapy, cell biological intervention, progenitor cell transplantation, surgical interventions, and bionic prosthetic studies.
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Affiliation(s)
- B W Jones
- Department of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City, Utah 84132, USA.
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18
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Berta ÁI, Boesze-Battaglia K, Genini S, Goldstein O, O'Brien PJ, Szél Á, Acland GM, Beltran WA, Aguirre GD. Photoreceptor cell death, proliferation and formation of hybrid rod/S-cone photoreceptors in the degenerating STK38L mutant retina. PLoS One 2011; 6:e24074. [PMID: 21980341 PMCID: PMC3184085 DOI: 10.1371/journal.pone.0024074] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 08/02/2011] [Indexed: 11/19/2022] Open
Abstract
A homozygous mutation in STK38L in dogs impairs the late phase of photoreceptor development, and is followed by photoreceptor cell death (TUNEL) and proliferation (PCNA, PHH3) events that occur independently in different cells between 7-14 weeks of age. During this period, the outer nuclear layer (ONL) cell number is unchanged. The dividing cells are of photoreceptor origin, have rod opsin labeling, and do not label with markers specific for macrophages/microglia (CD18) or Müller cells (glutamine synthetase, PAX6). Nestin labeling is absent from the ONL although it labels the peripheral retina and ciliary marginal zone equally in normals and mutants. Cell proliferation is associated with increased cyclin A1 and LATS1 mRNA expression, but CRX protein expression is unchanged. Coincident with photoreceptor proliferation is a change in the photoreceptor population. Prior to cell death the photoreceptor mosaic is composed of L/M- and S-cones, and rods. After proliferation, both cone types remain, but the majority of rods are now hybrid photoreceptors that express rod opsin and, to a lesser extent, cone S-opsin, and lack NR2E3 expression. The hybrid photoreceptors renew their outer segments diffusely, a characteristic of cones. The results indicate the capacity for terminally differentiated, albeit mutant, photoreceptors to divide with mutations in this novel retinal degeneration gene.
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Affiliation(s)
- Ágnes I. Berta
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvanis, United States of America
- Department of Human Morphology and Developmental Biology, Semmelweis University of Medicine, Budapest, Hungary
| | - Kathleen Boesze-Battaglia
- School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sem Genini
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvanis, United States of America
| | - Orly Goldstein
- J.A. Baker Institute, College of Veterinary Medicine, Cornell University, Ithaca New York, United States of America
| | - Paul J. O'Brien
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ágoston Szél
- Department of Human Morphology and Developmental Biology, Semmelweis University of Medicine, Budapest, Hungary
| | - Gregory M. Acland
- J.A. Baker Institute, College of Veterinary Medicine, Cornell University, Ithaca New York, United States of America
| | - William A. Beltran
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvanis, United States of America
| | - Gustavo D. Aguirre
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvanis, United States of America
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Cideciyan AV, Rachel RA, Aleman TS, Swider M, Schwartz SB, Sumaroka A, Roman AJ, Stone EM, Jacobson SG, Swaroop A. Cone photoreceptors are the main targets for gene therapy of NPHP5 (IQCB1) or NPHP6 (CEP290) blindness: generation of an all-cone Nphp6 hypomorph mouse that mimics the human retinal ciliopathy. Hum Mol Genet 2011; 20:1411-23. [PMID: 21245082 DOI: 10.1093/hmg/ddr022] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Leber congenital amaurosis (LCA), a severe autosomal recessive childhood blindness, is caused by mutations in at least 15 genes. The most common molecular form is a ciliopathy due to NPHP6 (CEP290) mutations and subjects have profound loss of vision. A similarly severe phenotype occurs in the related ciliopathy NPHP5 (IQCB1)-LCA. Recent success of retinal gene therapy in one form of LCA prompted the question whether we know enough about human NPHP5 and NPHP6 disease to plan such treatment. We determined that there was early-onset rapid degeneration of rod photoreceptors in young subjects with these ciliopathies. Rod outer segment (OS) lamination, when detectable, was disorganized. Retinal pigment epithelium lipofuscin accumulation indicated that rods had existed in the past in most subjects. In contrast to early rod losses, the all-cone human fovea in NPHP5- and NPHP6-LCA of all ages retained cone nuclei, albeit with abnormal inner segments and OS. The rd16 mouse, carrying a hypomorphic Nphp6 allele, was a good model of the rod-dominant human extra-foveal retina. Rd16 mice showed normal genesis of photoreceptors, including the formation of cilia, followed by abnormal elaboration of OS and rapid degeneration. To produce a model of the all-cone human fovea in NPHP6-LCA, we generated rd16;Nrl-/- double-mutant mice. They showed substantially retained cone photoreceptors with disproportionate cone function loss, such as in the human disease. NPHP5- and NPHP6-LCA across a wide age spectrum are thus excellent candidates for cone-directed gene augmentation therapy, and the rd16;Nrl-/- mouse is an appropriate model for pre-clinical proof-of-concept studies.
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Affiliation(s)
- Artur V Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
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20
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Hosch J, Lorenz B, Stieger K. RPGR: role in the photoreceptor cilium, human retinal disease, and gene therapy. Ophthalmic Genet 2010; 32:1-11. [PMID: 21174525 DOI: 10.3109/13816810.2010.535889] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cilia are specialized dynamic organelles extending from the surface of almost all mammalian cells. Since proteins and protein precursors are transported across the ciliary compartments via intraflagellar transport (IFT), mutations in genes encoding proteins that participate in IFT can cause a spectrum of different ciliopathies. Photoreceptors of the mammalian retina contain ciliary structures that connect the inner (IS) with the outer segments (OS). This structure, the connecting cilium (CC), serves as the only junction between OS and IS, the correct passage of proteins through the CC is crucial for the functioning and maintenance of the cells. Therefore, any impairment of the IFT leads to severe malfunction of photoreceptors, and may induce apoptosis ultimately leading to the degeneration of the retina. The Retinitis Pigmentosa GTPase Regulator (RPGR), which is located in the CC, participates in the IFT and interacts with a variety of proteins, including RPGRIP-1, CEP290, NPM, SMC1 and 3 and IFT88. However, the function of RPGR through its interaction with these proteins is not yet entirely understood. Mutations in the RPGR gene lead to X-linked Retinitis pigmentosa (XLRP), one of the most severe and early onset forms of RP. Gene therapy is considered a potential therapeutic option and is currently under investigation in several animal models of XLRP. However, some of the currently available mouse models are only partially suitable for the development of therapeutic strategies and the quest for more appropriate small animal models is still an issue.
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Affiliation(s)
- Jutta Hosch
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
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21
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Yefimova MG, Messaddeq N, Karam A, Jacquard C, Weber C, Jonet L, Wolfrum U, Jeanny JC, Trottier Y. Polyglutamine toxicity induces rod photoreceptor division, morphological transformation or death in Spinocerebellar ataxia 7 mouse retina. Neurobiol Dis 2010; 40:311-24. [DOI: 10.1016/j.nbd.2010.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 06/03/2010] [Accepted: 06/11/2010] [Indexed: 12/01/2022] Open
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22
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El Sanharawi M, Kowalczuk L, Touchard E, Omri S, de Kozak Y, Behar-Cohen F. Protein delivery for retinal diseases: from basic considerations to clinical applications. Prog Retin Eye Res 2010; 29:443-65. [PMID: 20398784 DOI: 10.1016/j.preteyeres.2010.04.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Because the eye is protected by ocular barriers but is also easily accessible, direct intravitreous injections of therapeutic proteins allow for specific and targeted treatment of retinal diseases. Low doses of proteins are required in this confined environment and a long time of residency in the vitreous is expected, making the eye the ideal organ for local proteic therapies. Monthly intravitreous injection of Ranibizumab, an anti-VEGF Fab has become the standard of care for patients presenting wet AMD. It has brought the proof of concept that administering proteins into the physiologically low proteic concentration vitreous can be performed safely. Other antibodies, Fab, peptides and growth factors have been shown to exert beneficial effects on animal models when administered within the therapeutic and safe window. To extend the use of such biomolecules in the ophthalmology practice, optimization of treatment regimens and efficacy is required. Basic knowledge remains to be increased on how different proteins/peptides penetrate into the eye and the ocular tissues, distribute in the vitreous, penetrate into the retinal layers and/or cells, are eliminated from the eye or metabolized. This should serve as a basis for designing novel drug delivery systems. The later should be non-or minimally invasive and should allow for a controlled, scalable and sustained release of the therapeutic proteins in the ocular media. This paper reviews the actual knowledge regarding protein delivery for eye diseases and describes novel non-viral gene therapy technologies particularly adapted for this purpose.
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Affiliation(s)
- M El Sanharawi
- Inserm, UMRS 872, Centre de Recherche des Cordeliers, Paris, France
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23
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Exogenous modulation of intrinsic optic nerve neuroprotective activity. Graefes Arch Clin Exp Ophthalmol 2010; 248:1105-16. [PMID: 20229104 DOI: 10.1007/s00417-010-1336-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 02/06/2010] [Accepted: 02/14/2010] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND To characterize the molecular and functional status of the rat retina and optic nerve after acute elevation of intraocular pressure (IOP). METHODS Retinal ischemia was induced in rats by increasing the IOP (110 mmHg/60 minutes). Microarray analysis, quantitative RT-PCR (qRT-PCR) and immunohistochemistry were used to characterize retinal tissue. PLGA microspheres containing neurotrophic factors (BDNF, GDNF, or CNTF) or empty microspheres were injected into the vitreous of operated animals 1 day after elevation of IOP. Pupil light reflex (PLR) parameters and electroretinograms (ERG) were monitored at multiple time points during the 60-day postoperative recovery period. RESULTS Molecular analysis showed a significant intrinsic up-regulation of CNTF at 10 and 25 days after induction of the acute ocular hypertension (p = 0.0067). Molecular tissue analysis of GDNF and its receptors (GDNFR1, GDNFR2), and BDNF and its receptor (trkB) showed no change in expression. Animals that received CNTF microspheres had no significant functional recovery compared to animals which received blank microspheres (p > 0.05). Animals that received GDNF or BDNF microspheres showed significant PLR recovery (p < 0.05 and p < 0.001 respectively) compared to non-treated animals. CONCLUSIONS Continuous release of neurotrophic growth factors (NGFs) significantly protects optic nerve function in the experimental model of retinal ischemia observed by PLR analysis.
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Ingham ES, Günhan E, Fuller PM, Fuller CA. Immunotoxin-induced ablation of melanopsin retinal ganglion cells in a non-murine mammalian model. J Comp Neurol 2009; 516:125-40. [PMID: 19575450 DOI: 10.1002/cne.22103] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In mammals, non-image-forming visual functions, including circadian photoentrainment and the pupillary light reflex, are thought to be mediated by the combination of rods, cones, and the melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs). Although several genetic models have been developed to clarify the individual roles of the rod, cone, and ipRGC systems in mediating non-image visual function, assessing the in vivo role(s) of the ipRGCs has been complicated by the possibility of ontogenetic issues in these genetically modified animal models. In the present study, we describe the development and validation of an immunotoxin that specifically targets the ipRGC population in the mature mammalian retina. This ipRGC immunotoxin, consisting of saporin conjugated to a melanopsin polyclonal antibody, was evaluated with respect to its effectiveness and specificity in depleting the ipRGC population in the fully developed rat retina. The results showed that the ipRGC toxin rapidly and permanently depleted approximately 70% of the ipRGC population, without inducing appreciable changes in the cell number or morphology of any of the non-melanopsin-containing retinal cell populations investigated. These findings suggest that the newly developed ipRGC immunotoxin provides a potent method for achieving relatively rapid, permanent, and selective depletion of the ipRGC population in a non-murine model system. The development of this ipRGC-ablation method is the next step in elucidating the role of ipRGCs in mediating non-visual and circadian light-resetting responses in a wide range of non-murine mammalian models.
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Affiliation(s)
- Elizabeth S Ingham
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, California 95616, USA
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Beltran WA, Allore HG, Johnson E, Towle V, Tao W, Acland GM, Aguirre GD, Zeiss CJ. CREB1/ATF1 activation in photoreceptor degeneration and protection. Invest Ophthalmol Vis Sci 2009; 50:5355-63. [PMID: 19643965 DOI: 10.1167/iovs.09-3741] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The cAMP response element binding protein 1 (CREB1) and activating transcription factor 1 (ATF1) are closely related members of the bZIP superfamily of transcription factors. Both are activated in response to a wide array of stimuli, including cellular stress. This study was conducted to assess the CREB1/ATF1 pathway in photoreceptor disease and protection. METHODS The expression levels of p-CREB1, CREB1, and ATF1 were examined by immunoblot and immunohistochemistry in normal canine retina and retinas of several canine models of retinal degeneration (rcd1, rcd2, erd, prcd, XLPRA1, XLPRA2, T4R RHO). Humans retinas affected with age-related macular degeneration (AMD) were also examined. p-CREB1/ATF1 immunolabeling was assessed in normal and rcd1 dogs treated with ciliary neurotrophic factor (CNTF), to examine the effect of a neuroprotective stimulus on activation of CREB1/ATF1. RESULTS Native CREB1 and ATF1 as well as phosphorylated CREB1/ATF1 was examined in normal canine retina by immunoblot. The p-CREB1 antibody identified phosphorylated CREB1 and ATF1 and labeled the inner retina only in normal dogs. In degenerate canine and human retinas, strong immunolabeling appeared in rod and cone photoreceptors, indicating increased expression of native CREB1 and ATF1, as well as increased phosphorylation of these proteins. Retinal protection by CNTF in rcd1 dogs was accompanied by a significant increase in the number of p-CREB1/ATF1-labeled photoreceptor nuclei. CONCLUSIONS Positive association of CREB1/ATF1 phosphorylation with photoreceptor protection suggests that it may contribute to an innate protective response. These data identify a signaling mechanism in rods and cones of potential importance for therapies of RP and AMD.
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Affiliation(s)
- William A Beltran
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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26
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Beltran WA. The use of canine models of inherited retinal degeneration to test novel therapeutic approaches. Vet Ophthalmol 2009; 12:192-204. [PMID: 19392879 DOI: 10.1111/j.1463-5224.2009.00694.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Inherited retinal degenerations (RDs) are a common cause of blindness in dogs and in humans. Over the past two decades numerous genes causally associated with these diseases have been identified and several canine models have been used to improve our understanding of the molecular mechanisms of RDs, as well as to test the proof of principle and safety of novel therapies. This review briefly summarizes the drug delivery approaches and therapeutic strategies that have been and are currently tested in dogs, with a particular emphasis on corrective gene therapy, and retinal neuroprotection.
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Affiliation(s)
- William A Beltran
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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27
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Aleman TS, Cideciyan AV, Sumaroka A, Schwartz SB, Roman AJ, Windsor EAM, Steinberg JD, Branham K, Othman M, Swaroop A, Jacobson SG. Inner retinal abnormalities in X-linked retinitis pigmentosa with RPGR mutations. Invest Ophthalmol Vis Sci 2007; 48:4759-65. [PMID: 17898302 PMCID: PMC3178894 DOI: 10.1167/iovs.07-0453] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To investigate in vivo the retinal microstructure in X-linked retinitis pigmentosa (XLRP) caused by RPGR mutations as a prelude to treatment initiatives for this common form of RP. METHODS Patients with RPGR-XLRP (n = 12; age range, 10-56 years) were studied by optical coherence tomography (OCT) in a wide region of central retina. Overall retinal thickness and outer nuclear layer (ONL) and inner retinal parameters across horizontal and vertical meridians were analyzed and compared. RESULTS Retinal architecture of all patients with RPGR mutations was abnormal. At the fovea in younger patients, the ONL could be normal; but, at increasing eccentricities, there was a loss of photoreceptor laminar structure, even at the youngest ages studied. At later ages and advanced disease stages, the ONL was thin and reduced in extent. Inner retinal thickness, in contrast, was normal or hyperthick. Inner retinal thickening was detectable at all ages studied and was strongly associated with ONL loss. CONCLUSIONS Inner retinal laminar abnormalities in RPGR-XLRP are likely to reflect a neuronal-glial retinal remodeling response to photoreceptor loss and are detectable relatively early in the disease course. These results should be factored into emerging therapeutic strategies for this form of RP.
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Affiliation(s)
- Tomas S Aleman
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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