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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Appell MB, Pejavar J, Pasupathy A, Rompicharla SVK, Abbasi S, Malmberg K, Kolodziejski P, Ensign LM. Next generation therapeutics for retinal neurodegenerative diseases. J Control Release 2024; 367:708-736. [PMID: 38295996 PMCID: PMC10960710 DOI: 10.1016/j.jconrel.2024.01.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 01/05/2024] [Accepted: 01/28/2024] [Indexed: 02/13/2024]
Abstract
Neurodegenerative diseases affecting the visual system encompass glaucoma, macular degeneration, retinopathies, and inherited genetic disorders such as retinitis pigmentosa. These ocular pathologies pose a serious burden of visual impairment and blindness worldwide. Current treatment modalities include small molecule drugs, biologics, or gene therapies, most of which are administered topically as eye drops or as injectables. However, the topical route of administration faces challenges in effectively reaching the posterior segment and achieving desired concentrations at the target site, while injections and implants risk severe complications, such as retinal detachment and endophthalmitis. This necessitates the development of innovative therapeutic strategies that can prolong drug release, deliver effective concentrations to the back of the eye with minimal systemic exposure, and improve patient compliance and safety. In this review, we introduce retinal degenerative diseases, followed by a discussion of the existing clinical standard of care. We then delve into detail about drug and gene delivery systems currently in preclinical and clinical development, including formulation and delivery advantages/drawbacks, with a special emphasis on potential for clinical translation.
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Affiliation(s)
- Matthew B Appell
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Jahnavi Pejavar
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Ashwin Pasupathy
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Sri Vishnu Kiran Rompicharla
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Saed Abbasi
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Kiersten Malmberg
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Patricia Kolodziejski
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Laura M Ensign
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21231, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Departments of Gynecology and Obstetrics, Biomedical Engineering, Oncology, and Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA.
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Baehr W, Tsang SH. Gene therapy and therapeutic editing with outer or inner retina animal models. Vision Res 2023; 213:108316. [PMID: 37717278 PMCID: PMC10872789 DOI: 10.1016/j.visres.2023.108316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 09/19/2023]
Affiliation(s)
- Wolfgang Baehr
- Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, UT 84132, USA.
| | - Stephen H Tsang
- Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initative, New York, NY 10032, USA.
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Du W, Li J, Tang X, Yu W, Zhao M. CRISPR/SaCas9-based gene editing rescues photoreceptor degeneration throughout a rhodopsin-associated autosomal dominant retinitis pigmentosa mouse model. Exp Biol Med (Maywood) 2023; 248:1818-1828. [PMID: 37837380 PMCID: PMC10792415 DOI: 10.1177/15353702231199069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/12/2023] [Indexed: 10/16/2023] Open
Abstract
Rhodopsin (Rho) gene mutation was considered the highest prevalent mutation in autosomal dominant retinitis pigmentosa (ADRP); however, effective therapeutics for ADRP have not been developed. The process of gene editing via the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system offers the potentiality to provide cures for dominantly inherited disorders. Herein, we generated a CRISPR/SaCas9-mediated gene reduction system to inactivate the Rho mutant, while replacing normal rhodopsin in a rhodopsin mutation mouse model. When Rho-P23H knock-in mice were administered a subretinal injection of the "reduction and replacement" system, the expression of mutant rhodopsin was reduced, and retinal function was improved. Therefore, we concluded that CRISPR/SaCas9-based "reduction and replacement" gene therapy could provide structural and functional benefits for Rho mutant ADRP, as well as new directions for future clinical research on the treatment of such gain-of-function genetic diseases.
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Affiliation(s)
- Wei Du
- Department of Ophthalmology and Clinical Centre of Optometry, Peking University People’s Hospital, Beijing 100044, China
- Eye Diseases and Optometry Institute, Peking University People’s Hospital, Beijing 100044, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing 100044, China
- College of Optometry, Peking University Health Science Center, Beijing 100044, China
| | - Jiarui Li
- Department of Ophthalmology and Clinical Centre of Optometry, Peking University People’s Hospital, Beijing 100044, China
- Eye Diseases and Optometry Institute, Peking University People’s Hospital, Beijing 100044, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing 100044, China
- College of Optometry, Peking University Health Science Center, Beijing 100044, China
| | - Xin Tang
- Department of Ophthalmology and Clinical Centre of Optometry, Peking University People’s Hospital, Beijing 100044, China
- Eye Diseases and Optometry Institute, Peking University People’s Hospital, Beijing 100044, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing 100044, China
- College of Optometry, Peking University Health Science Center, Beijing 100044, China
| | - Wenzhen Yu
- Department of Ophthalmology and Clinical Centre of Optometry, Peking University People’s Hospital, Beijing 100044, China
- Eye Diseases and Optometry Institute, Peking University People’s Hospital, Beijing 100044, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing 100044, China
- College of Optometry, Peking University Health Science Center, Beijing 100044, China
| | - Mingwei Zhao
- Department of Ophthalmology and Clinical Centre of Optometry, Peking University People’s Hospital, Beijing 100044, China
- Eye Diseases and Optometry Institute, Peking University People’s Hospital, Beijing 100044, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing 100044, China
- College of Optometry, Peking University Health Science Center, Beijing 100044, China
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Zhen F, Zou T, Wang T, Zhou Y, Dong S, Zhang H. Rhodopsin-associated retinal dystrophy: Disease mechanisms and therapeutic strategies. Front Neurosci 2023; 17:1132179. [PMID: 37077319 PMCID: PMC10106759 DOI: 10.3389/fnins.2023.1132179] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/13/2023] [Indexed: 04/05/2023] Open
Abstract
Rhodopsin is a light-sensitive G protein-coupled receptor that initiates the phototransduction cascade in rod photoreceptors. Mutations in the rhodopsin-encoding gene RHO are the leading cause of autosomal dominant retinitis pigmentosa (ADRP). To date, more than 200 mutations have been identified in RHO. The high allelic heterogeneity of RHO mutations suggests complicated pathogenic mechanisms. Here, we discuss representative RHO mutations as examples to briefly summarize the mechanisms underlying rhodopsin-related retinal dystrophy, which include but are not limited to endoplasmic reticulum stress and calcium ion dysregulation resulting from protein misfolding, mistrafficking, and malfunction. Based on recent advances in our understanding of disease mechanisms, various treatment methods, including adaptation, whole-eye electrical stimulation, and small molecular compounds, have been developed. Additionally, innovative therapeutic treatment strategies, such as antisense oligonucleotide therapy, gene therapy, optogenetic therapy, and stem cell therapy, have achieved promising outcomes in preclinical disease models of rhodopsin mutations. Successful translation of these treatment strategies may effectively ameliorate, prevent or rescue vision loss related to rhodopsin mutations.
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Affiliation(s)
- Fangyuan Zhen
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, China
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Tongdan Zou
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Ting Wang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yongwei Zhou
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, China
| | - Shuqian Dong
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, China
- *Correspondence: Shuqian Dong, ; Houbin Zhang,
| | - Houbin Zhang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, Chengdu, Sichuan, China
- *Correspondence: Shuqian Dong, ; Houbin Zhang,
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CDHR1-Related Cone-Rod Dystrophy: Clinical Characteristics, Imaging Findings, and Genetic Test Results-A Case Report. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59020399. [PMID: 36837600 PMCID: PMC9966332 DOI: 10.3390/medicina59020399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023]
Abstract
Background: Cone-rod dystrophies (CRDs) are a heterogeneous group of inherited retinal diseases (IRDs) characterized by cone photoreceptor loss, that is followed by subsequent rod photoreceptor impairment. Case presentation: A 49-year-old man complaining of diminution of vision in both eyes (OU) was referred to our outpatient clinic. He reported visual loss for 5 years, but it was most progressive during the last few months. The best-corrected visual acuity (BCVA) at presentation was 0.4 in the right eye (RE) and 1.0 in the left eye (LE). Fundus fluorescein angiography (FFA) revealed granular hyperfluorescence in the macula and concomitant areas of capillary atrophy. Flash full-field electroretinography (ffERG) showed lowering of a and b waves as well as prolonged peak time in light-adapted conditions. However, outcomes of dark-adapted ERGs were within normal limits. Based on the constellation of clinical, angiographic, and electrophysiological tests findings, a diagnosis of IRD was suspected. Genetic testing showed a homozygous, pathogenic c.783G>A mutation in the cadherin-related family member 1 (CDHR1) gene, which confirmed CRD type 15 (CRD15). Conclusions: We demonstrate the clinical characteristics, retinal imaging outcomes, and genetic test results of a patient with CRD15. Our case contributes to expanding our knowledge of the clinical involvement of the pathogenic mutation c.783G>A in CDHR1 variants.
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RNA-targeting strategies as a platform for ocular gene therapy. Prog Retin Eye Res 2023; 92:101110. [PMID: 35840489 DOI: 10.1016/j.preteyeres.2022.101110] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/28/2022] [Accepted: 07/06/2022] [Indexed: 02/01/2023]
Abstract
Genetic medicine is offering hope as new therapies are emerging for many previously untreatable diseases. The eye is at the forefront of these advances, as exemplified by the approval of Luxturna® by the United States Food and Drug Administration (US FDA) in 2017 for the treatment of one form of Leber Congenital Amaurosis (LCA), an inherited blindness. Luxturna® was also the first in vivo human gene therapy to gain US FDA approval. Numerous gene therapy clinical trials are ongoing for other eye diseases, and novel delivery systems, discovery of new drug targets and emerging technologies are currently driving the field forward. Targeting RNA, in particular, is an attractive therapeutic strategy for genetic disease that may have safety advantages over alternative approaches by avoiding permanent changes in the genome. In this regard, antisense oligonucleotides (ASO) and RNA interference (RNAi) are the currently popular strategies for developing RNA-targeted therapeutics. Enthusiasm has been further fuelled by the emergence of clustered regularly interspersed short palindromic repeats (CRISPR)-CRISPR associated (Cas) systems that allow targeted manipulation of nucleic acids. RNA-targeting CRISPR-Cas systems now provide a novel way to develop RNA-targeted therapeutics and may provide superior efficiency and specificity to existing technologies. In addition, RNA base editing technologies using CRISPR-Cas and other modalities also enable precise alteration of single nucleotides. In this review, we showcase advances made by RNA-targeting systems for ocular disease, discuss applications of ASO and RNAi technologies, highlight emerging CRISPR-Cas systems and consider the implications of RNA-targeting therapeutics in the development of future drugs to treat eye disease.
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Ren ZL, Zhang HB, Li L, Yang ZL, Jiang L. Characterization of two novel knock-in mouse models of syndromic retinal ciliopathy carrying hypomorphic Sdccag8 mutations. Zool Res 2022; 43:442-456. [PMID: 35503560 PMCID: PMC9113982 DOI: 10.24272/j.issn.2095-8137.2021.387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/21/2022] [Indexed: 11/07/2022] Open
Abstract
Mutations in serologically defined colon cancer autoantigen protein 8 ( SDCCAG8) were first identified in retinal ciliopathy families a decade ago with unknown function. To investigate the pathogenesis of SDCCAG8-associated retinal ciliopathies in vivo, we employed CRISPR/Cas9-mediated homology-directed recombination (HDR) to generate two knock-in mouse models, Sdccag8Y236X/Y236X and Sdccag8E451GfsX467/E451GfsX467 , which carry truncating mutations of the mouse Sdccag8, corresponding to mutations that cause Bardet-Biedl syndrome (BBS) and Senior-Løken syndrome (SLS) (c.696T>G p.Y232X and c.1339-1340insG p.E447GfsX463) in humans, respectively. The two mutant Sdccag8 knock-in mice faithfully recapitulated human SDCCAG8-associated BBS phenotypes such as rod-cone dystrophy, cystic renal disorder, polydactyly, infertility, and growth retardation, with varied age of onset and severity depending on the hypomorphic strength of the Sdccag8 mutations. To the best of our knowledge, these knock-in mouse lines are the first BBS mouse models to present with the polydactyly phenotype. Major phototransduction protein mislocalization was also observed outside the outer segment after initiation of photoreceptor degeneration. Impaired cilia were observed in the mutant photoreceptors, renal epithelial cells, and mouse embryonic fibroblasts derived from the knock-in mouse embryos, suggesting that SDCCAG8 plays an essential role in ciliogenesis, and cilium defects are a primary driving force of SDCCAG8-associated retinal ciliopathies.
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Affiliation(s)
- Zhi-Lin Ren
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Hou-Bin Zhang
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, Sichuan 610072, China
| | - Lin Li
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, Sichuan 610072, China
| | - Zheng-Lin Yang
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, Sichuan 610072, China. E-mail:
| | - Li Jiang
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, Sichuan 610072, China . E-mail:
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Yang L, Slone J, Li Z, Lou X, Hu YC, Queme LF, Jankowski MP, Huang T. Systemic administration of AAV-Slc25a46 mitigates mitochondrial neuropathy in Slc25a46-/- mice. Hum Mol Genet 2021; 29:649-661. [PMID: 31943007 DOI: 10.1093/hmg/ddz277] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/10/2019] [Accepted: 11/11/2019] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial disorders are the result of nuclear and mitochondrial DNA mutations that affect multiple organs, with the central and peripheral nervous system often affected. Currently, there is no cure for mitochondrial disorders. Currently, gene therapy offers a novel approach for treating monogenetic disorders, including nuclear genes associated with mitochondrial disorders. We utilized a mouse model carrying a knockout of the mitochondrial fusion-fission-related gene solute carrier family 25 member 46 (Slc25a46) and treated them with neurotrophic AAV-PHP.B vector carrying the mouse Slc25a46 coding sequence. Thereafter, we used immunofluorescence staining and western blot to test the transduction efficiency of this vector. Toluidine blue staining and electronic microscopy were utilized to assess the morphology of optic and sciatic nerves following treatment, and the morphology and respiratory chain activity of mitochondria within these tissues were determined as well. The adeno-associated virus (AAV) vector effectively transduced in the cerebrum, cerebellum, heart, liver and sciatic nerves. AAV-Slc25a46 treatment was able to rescue the premature death in the mutant mice (Slc25a46-/-). The treatment-improved electronic conductivity of the peripheral nerves increased mobility and restored mitochondrial complex activities. Most notably, mitochondrial morphology inside the tissues of both the central and peripheral nervous systems was normalized, and the neurodegeneration, chronic neuroinflammation and loss of Purkinje cell dendrites observed within the mutant mice were alleviated. Overall, our study shows that AAV-PHP.B's neurotrophic properties are plausible for treating conditions where the central nervous system is affected, such as many mitochondrial diseases, and that AAV-Slc25a46 could be a novel approach for treating SLC25A46-related mitochondrial disorders.
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Affiliation(s)
- Li Yang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.,Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jesse Slone
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Zhuo Li
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.,State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Xiaoting Lou
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.,School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yueh-Chiang Hu
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Luis F Queme
- Division of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Michael P Jankowski
- Division of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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10
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Botto C, Rucli M, Tekinsoy MD, Pulman J, Sahel JA, Dalkara D. Early and late stage gene therapy interventions for inherited retinal degenerations. Prog Retin Eye Res 2021; 86:100975. [PMID: 34058340 DOI: 10.1016/j.preteyeres.2021.100975] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/18/2021] [Accepted: 05/21/2021] [Indexed: 12/12/2022]
Abstract
Inherited and age-related retinal degeneration is the hallmark of a large group of heterogeneous diseases and is the main cause of untreatable blindness today. Genetic factors play a major pathogenic role in retinal degenerations for both monogenic diseases (such as retinitis pigmentosa) and complex diseases with established genetic risk factors (such as age-related macular degeneration). Progress in genotyping techniques and back of the eye imaging are completing our understanding of these diseases and their manifestations in patient populations suffering from retinal degenerations. It is clear that whatever the genetic cause, the majority of vision loss in retinal diseases results from the loss of photoreceptor function. The timing and circumstances surrounding the loss of photoreceptor function determine the adequate therapeutic approach to use for each patient. Among such approaches, gene therapy is rapidly becoming a therapeutic reality applicable in the clinic. This massive move from laboratory work towards clinical application has been propelled by the advances in our understanding of disease genetics and mechanisms, gene delivery vectors, gene editing systems, and compensatory strategies for loss of photoreceptor function. Here, we provide an overview of existing modalities of retinal gene therapy and their relevance based on the needs of patient populations suffering from inherited retinal degenerations.
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Affiliation(s)
- Catherine Botto
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Marco Rucli
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Müge Defne Tekinsoy
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Juliette Pulman
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France; Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, United States; CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, F-75012, Paris, France; Fondation Ophtalmologique Rothschild, F-75019, Paris, France
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France.
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11
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Georgiou M, Fujinami K, Michaelides M. Inherited retinal diseases: Therapeutics, clinical trials and end points-A review. Clin Exp Ophthalmol 2021; 49:270-288. [PMID: 33686777 DOI: 10.1111/ceo.13917] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/22/2021] [Accepted: 03/01/2021] [Indexed: 12/18/2022]
Abstract
Inherited retinal diseases (IRDs) are a clinically and genetically heterogeneous group of disorders characterised by photoreceptor degeneration or dysfunction. These disorders typically present with severe vision loss that can be progressive, with disease onset ranging from congenital to late adulthood. The advances in genetics, retinal imaging and molecular biology, have conspired to create the ideal environment for establishing treatments for IRDs, with the first approved gene therapy and the commencement of multiple clinical trials. The scope of this review is to familiarise clinicians and scientists with the current management and the prospects for novel therapies for: (1) macular dystrophies, (2) cone and cone-rod dystrophies, (3) cone dysfunction syndromes, (4) Leber congenital amaurosis, (5) rod-cone dystrophies, (6) rod dysfunction syndromes and (7) chorioretinal dystrophies. We also briefly summarise the investigated end points for the ongoing trials.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Kaoru Fujinami
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
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12
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Gao M, Liu H, Xiao Y, Guo Y, Wan X, Li X, Li M, Liang J, Zhai Y, Liu W, Jiang M, Luo X, Sun X. xCT regulates redox homeostasis and promotes photoreceptor survival after retinal detachment. Free Radic Biol Med 2020; 158:32-43. [PMID: 32679366 DOI: 10.1016/j.freeradbiomed.2020.06.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 05/17/2020] [Accepted: 06/08/2020] [Indexed: 01/20/2023]
Abstract
BACKGROUNDS Photoreceptor degeneration underlies various retinal disorders that lead to vision impairment. Currently, no effective medication is available to rescue photoreceptors under disease conditions. Elucidation of the molecular pathways involved in photoreceptor degeneration is a prerequisite for the rational design of therapeutic interventions. Photoreceptors are among the most energy-demanding tissues that require highly active oxidative phosphorylation. Therefore, disruption of metabolic support to photoreceptors results in a redox imbalance and subsequent cell death. We hypothesize that the redox regulatory pathway could be a potential therapeutic target to rescue photoreceptors under disease conditions. METHODS Experimental retinal detachment was induced in mice. A murine photoreceptor-derived 661w cell line treated with H2O2 was employed as an in vitro model to study the cellular response to oxidative stress. The expression and functional role of xCT, an upstream regulator of redox homeostasis, was assessed in vivo and in vitro. An xCT expression vector was constructed for an in vivo study to evaluate the therapeutic potential of this molecule. RESULTS xCT expression was upregulated in detached retina and H2O2-stimulated 661w cells compared to the control cells. Pharmacological inhibition of xCT by sulfasalazine (SAS) promoted photoreceptor degeneration after retinal detachment and 661w cell death upon H2O2 treatment. Additionally, SAS treatment induced reactive oxidative species (ROS) accumulation, glutathione (GSH) depletion, and glutamate release in 661w cells. In contrast, xCT overexpression via viral infection protected photoreceptors from degeneration after retinal detachment. CONCLUSION We conclude that xCT expression is upregulated in photoreceptors after retinal detachment and plays a neuroprotective role in preserving photoreceptors. Mechanistically, xCT promotes cellular homeostasis by regulating intracellular ROS and GSH levels, which are critical to photoreceptor survival after retinal detachment. Collectively, our findings identify xCT as a potential therapeutic target for protection of photoreceptors under disease conditions.
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Affiliation(s)
- Min Gao
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, 200080, Shanghai, China
| | - Haiyun Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, 200080, Shanghai, China
| | - Yushu Xiao
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, 200080, Shanghai, China
| | - Yinong Guo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, 200080, Shanghai, China
| | - Xiaoling Wan
- Shanghai Key Laboratory of Fundus Diseases, 200080, Shanghai, China
| | - Xiaomeng Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, 200080, Shanghai, China
| | - Min Li
- Shanghai Key Laboratory of Fundus Diseases, 200080, Shanghai, China
| | - Jian Liang
- Shanghai Key Laboratory of Fundus Diseases, 200080, Shanghai, China
| | - Yuanqi Zhai
- Shanghai Key Laboratory of Fundus Diseases, 200080, Shanghai, China
| | - Wenjia Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, 200080, Shanghai, China
| | - Mei Jiang
- Shanghai Key Laboratory of Fundus Diseases, 200080, Shanghai, China
| | - Xueting Luo
- Shanghai Key Laboratory of Fundus Diseases, 200080, Shanghai, China
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, 200080, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, 200080, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, 200080, Shanghai, China.
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13
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Moore SM, Skowronska-Krawczyk D, Chao DL. Emerging Concepts for RNA Therapeutics for Inherited Retinal Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1185:85-89. [PMID: 31884593 DOI: 10.1007/978-3-030-27378-1_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Inherited retinal diseases (IRD) encompass a wide spectrum of hereditary blindness with significant genetic heterogeneity. Therapeutics regulating gene expression on an RNA level have significant promise for treating IRD. In this review, we review the molecular basis of oligonucleotide therapeutics such as ribozymes, RNA interference (RNAi), antisense oligonucleotides (ASO), CRISPRi/a, and their applications to treatments of IRD.
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Affiliation(s)
- Spencer M Moore
- Medical Scientist Training Program, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, La Jolla, CA, USA
| | - Daniel L Chao
- Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, La Jolla, CA, USA.
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14
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Gill JS, Georgiou M, Kalitzeos A, Moore AT, Michaelides M. Progressive cone and cone-rod dystrophies: clinical features, molecular genetics and prospects for therapy. Br J Ophthalmol 2019; 103:bjophthalmol-2018-313278. [PMID: 30679166 PMCID: PMC6709772 DOI: 10.1136/bjophthalmol-2018-313278] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/23/2018] [Accepted: 11/29/2018] [Indexed: 12/16/2022]
Abstract
Progressive cone and cone-rod dystrophies are a clinically and genetically heterogeneous group of inherited retinal diseases characterised by cone photoreceptor degeneration, which may be followed by subsequent rod photoreceptor loss. These disorders typically present with progressive loss of central vision, colour vision disturbance and photophobia. Considerable progress has been made in elucidating the molecular genetics and genotype-phenotype correlations associated with these dystrophies, with mutations in at least 30 genes implicated in this group of disorders. We discuss the genetics, and clinical, psychophysical, electrophysiological and retinal imaging characteristics of cone and cone-rod dystrophies, focusing particularly on four of the most common disease-associated genes: GUCA1A, PRPH2, ABCA4 and RPGR Additionally, we briefly review the current management of these disorders and the prospects for novel therapies.
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Affiliation(s)
- Jasdeep S Gill
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, London, UK
- Ophthalmology Department, University of California San Francisco School of Medicine, San Francisco, California, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
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15
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Shinohara Y, Konno A, Nitta K, Matsuzaki Y, Yasui H, Suwa J, Hiromura K, Hirai H. Effects of Neutralizing Antibody Production on AAV-PHP.B-Mediated Transduction of the Mouse Central Nervous System. Mol Neurobiol 2018; 56:4203-4214. [PMID: 30291583 DOI: 10.1007/s12035-018-1366-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 09/25/2018] [Indexed: 01/02/2023]
Abstract
Adeno-associated virus (AAV)-PHP.B, a capsid variant of AAV serotype 9, is highly permeable to the blood-brain barrier. A major obstacle to the systemic use of AAV-PHP.B is the generation of neutralizing antibodies (NAbs); however, temporal profiles of NAb production after exposure to AAV-PHP.B, and the influence on later AAV-PHP.B administration, remains unknown. To address these, AAV-PHP.Bs expressing either GFP or mCherry by neuron-specific or astrocyte-specific promoters were intravenously administered to mice at various intervals, and brain expression was examined. Injection of two AAV-PHP.Bs, separated temporally, showed that as little as a 1-day interval between injections resulted in a significant decrease in expression of the second transgene, with a complete loss of expression after 7 days, paralleling an increase in serum NAb titers. Brain parenchymal injection was explored to circumvent the presence of NAbs. Mice systemically pre-treated with an AAV-PHP.B were injected intra-cerebrally with an AAV-PHP.B expressing GFP. After 2 weeks, marked GFP expression in the cerebellum was evident, showing that pre-existing NAbs did not affect the AAV-PHP.B directly injected into the brain. In contrast, reversing the injection order, i.e., cerebellar injection followed by systemic injection, completely eliminated expression of the second transgene. We confirmed that intra-cerebellar injection produced NAbs in the serum, but not in the cerebrospinal fluid (CSF). Our results indicate that the preclusion of brain transduction by a second AAV-PHP.B administration begins from the first day following systemic injection and is established within 1 week. Serum NAbs can be avoided by directly injecting AAV-PHP.Bs into brain tissue.
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Affiliation(s)
- Yoichiro Shinohara
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan.,Department of Ophthalmology, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Ayumu Konno
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Keisuke Nitta
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan.,Department of Ophthalmology, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Yasunori Matsuzaki
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Hiroyuki Yasui
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Junya Suwa
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Keiju Hiromura
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan. .,Research Program for Neural Signaling, Division of Endocrinology, Metabolism and Signal Research, Gunma University Initiative for Advanced Research, Maebashi, Gunma, 371-8511, Japan.
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16
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Li P, Kleinstiver BP, Leon MY, Prew MS, Navarro-Gomez D, Greenwald SH, Pierce EA, Joung JK, Liu Q. Allele-Specific CRISPR-Cas9 Genome Editing of the Single-Base P23H Mutation for Rhodopsin-Associated Dominant Retinitis Pigmentosa. CRISPR J 2018; 1:55-64. [PMID: 31021187 DOI: 10.1089/crispr.2017.0009] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Treatment strategies for dominantly inherited disorders typically involve silencing or ablating the pathogenic allele. CRISPR-Cas nucleases have shown promise in allele-specific knockout approaches when the dominant allele creates unique protospacer adjacent motifs that can lead to allele-restricted targeting. Here, we present a spacer-mediated allele-specific knockout approach that utilizes both SpCas9 variants and truncated single-guide RNAs to achieve efficient discrimination of a single-nucleotide mutation in rhodopsin (Rho)-P23H mice, a model of dominant retinitis pigmentosa. We found that approximately 45% of the mutant P23H allele was edited at the DNA level and that the relative RNA expression of wild-type Rho was about 2.8 times more than that of mutant Rho in treated retinas. Furthermore, the progression of photoreceptor cell degeneration in outer nuclear layer was significantly delayed in treated regions of the Rho-P23H retinas at 5 weeks of age. Our proof-of-concept study therefore outlines a general strategy that could potentially be expanded to examine the therapeutic benefit of allele-specific gene editing approach to treat human P23H patients. Our study also extends allele-specific editing strategies beyond discrimination within the protospacer adjacent motif sites, with potentially broad applicability to other dominant diseases.
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Affiliation(s)
- Pingjuan Li
- 1 Ocular Genomics Institute , Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,2 Department of Ophthalmology, Harvard Medical School , Boston, Massachusetts
| | - Benjamin P Kleinstiver
- 3 Molecular Pathology Unit and Center for Cancer Research, Massachusetts General Hospital , Charlestown, Massachusetts.,4 Center for Computational and Integrative Biology, Massachusetts General Hospital , Charlestown, Massachusetts.,5 Department of Pathology, Harvard Medical School, Boston, Massachusetts
| | - Mihoko Y Leon
- 1 Ocular Genomics Institute , Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,2 Department of Ophthalmology, Harvard Medical School , Boston, Massachusetts
| | - Michelle S Prew
- 3 Molecular Pathology Unit and Center for Cancer Research, Massachusetts General Hospital , Charlestown, Massachusetts.,4 Center for Computational and Integrative Biology, Massachusetts General Hospital , Charlestown, Massachusetts
| | - Daniel Navarro-Gomez
- 1 Ocular Genomics Institute , Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,2 Department of Ophthalmology, Harvard Medical School , Boston, Massachusetts
| | - Scott H Greenwald
- 1 Ocular Genomics Institute , Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,2 Department of Ophthalmology, Harvard Medical School , Boston, Massachusetts
| | - Eric A Pierce
- 1 Ocular Genomics Institute , Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,2 Department of Ophthalmology, Harvard Medical School , Boston, Massachusetts
| | - J Keith Joung
- 3 Molecular Pathology Unit and Center for Cancer Research, Massachusetts General Hospital , Charlestown, Massachusetts.,4 Center for Computational and Integrative Biology, Massachusetts General Hospital , Charlestown, Massachusetts.,5 Department of Pathology, Harvard Medical School, Boston, Massachusetts
| | - Qin Liu
- 1 Ocular Genomics Institute , Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,2 Department of Ophthalmology, Harvard Medical School , Boston, Massachusetts
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17
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Small GTPases Rab8a and Rab11a Are Dispensable for Rhodopsin Transport in Mouse Photoreceptors. PLoS One 2016; 11:e0161236. [PMID: 27529348 PMCID: PMC4987053 DOI: 10.1371/journal.pone.0161236] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/02/2016] [Indexed: 01/01/2023] Open
Abstract
Rab11a and Rab8a are ubiquitous small GTPases shown as required for rhodopsin transport in Xenopus laevis and zebrafish photoreceptors by dominant negative (dn) disruption of function. Here, we generated retina-specific Rab11a (retRab11a) and Rab8a (retRab8a) single and double knockout mice to explore the consequences in mouse photoreceptors. Rhodopsin and other outer segment (OS) membrane proteins targeted correctly to OS and electroretinogram (ERG) responses in all three mutant mouse lines were indistinguishable from wild-type (WT). Further, AAV (adeno-associated virus)-mediated expression of dnRab11b in retRab11a-/- retina, or expression of dnRab8b in retRab8a-/- retina did not cause OS protein mislocalization. Finally, a retRab8a-/- retina injected at one month of age with AAVs expressing dnRab11a, dnRab11b, dnRab8b, and dnRab10 (four dn viruses on Rab8a-/- background) and harvested three months later exhibited normal OS protein localization. In contrast to results obtained with dnRab GTPases in Xenopus and zebrafish, mouse Rab11a and Rab8a are dispensable for proper rhodopsin and outer segment membrane protein targeting. Absence of phenotype after expression of four dn Rab GTPases in a Rab8a-/- retina suggests that Rab8b and Rab11b paralogs maybe dispensable as well. Our data thus demonstrate significant interspecies variation in photoreceptor membrane protein and rhodopsin trafficking.
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18
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Peshenko IV, Olshevskaya EV, Dizhoor AM. Functional Study and Mapping Sites for Interaction with the Target Enzyme in Retinal Degeneration 3 (RD3) Protein. J Biol Chem 2016; 291:19713-23. [PMID: 27471269 DOI: 10.1074/jbc.m116.742288] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Indexed: 12/24/2022] Open
Abstract
Retinal degeneration 3 (RD3) protein, essential for normal expression of retinal membrane guanylyl cyclase (RetGC) in photoreceptor cells, blocks RetGC catalytic activity and stimulation by guanylyl cyclase-activating proteins (GCAPs). In a mouse retina, RD3 inhibited both RetGC1 and RetGC2 isozymes. Photoreceptors in the rd3/rd3 mouse retinas lacking functional RD3 degenerated more severely than in the retinas lacking both RetGC isozymes, consistent with a hypothesis that the inhibitory activity of RD3 has a functional role in photoreceptors. To map the potential target-binding site(s) on RD3, short evolutionary conserved regions of its primary structure were scrambled and the mutations were tested for the RD3 ability to inhibit RetGC1 and co-localize with the cyclase in co-transfected cells. Substitutions in 4 out of 22 tested regions, (87)KIHP(90), (93)CGPAI(97), (99)RFRQ(102), and (119)RSVL(122), reduced the RD3 apparent affinity for the cyclase 180-700-fold. Changes of amino acid sequences outside the Lys(87)-Leu(122) central portion of the molecule either failed to prevent RD3 binding to the cyclase or had a much smaller effect. Mutations in the (93)CGPAI(97) portion of a predicted central α-helix most drastically suppressed the inhibitory activity of RD3 and disrupted RD3 co-localization with RetGC1 in HEK293 cells. Different side chains replacing Cys(93) profoundly reduced RD3 affinity for the cyclase, irrespective of their relative helix propensities. We conclude that the main RetGC-binding interface on RD3 required for the negative regulation of the cyclase localizes to the Lys(87)-Leu(122) region.
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Affiliation(s)
- Igor V Peshenko
- From the Pennsylvania College of Optometry, Department of Research, Salus University, Elkins Park, Pennsylvania 19027
| | - Elena V Olshevskaya
- From the Pennsylvania College of Optometry, Department of Research, Salus University, Elkins Park, Pennsylvania 19027
| | - Alexander M Dizhoor
- From the Pennsylvania College of Optometry, Department of Research, Salus University, Elkins Park, Pennsylvania 19027
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Abstract
Severe loss of photoreceptor cells in inherited or acquired retinal degenerative diseases can result in partial loss of sight or complete blindness. The optogenetic strategy for restoration of vision utilizes optogenetic tools to convert surviving inner retinal neurons into photosensitive cells; thus, light sensitivity is imparted to the retina after the death of photoreceptor cells. Proof-of-concept studies, especially those using microbial rhodopsins, have demonstrated restoration of light responses in surviving retinal neurons and visually guided behaviors in animal models. Significant progress has also been made in improving microbial rhodopsin-based optogenetic tools, developing virus-mediated gene delivery, and targeting specific retinal neurons and subcellular compartments of retinal ganglion cells. In this article, we review the current status of the field and outline further directions and challenges to the advancement of this strategy toward clinical application and improvement in the outcomes of restored vision.
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Affiliation(s)
- Zhuo-Hua Pan
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan 48201; , , .,Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201;
| | - Qi Lu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201;
| | - Anding Bi
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan 48201; , ,
| | | | - Gary W Abrams
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan 48201; , ,
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20
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Jiang L, Tam BM, Ying G, Wu S, Hauswirth WW, Frederick JM, Moritz OL, Baehr W. Kinesin family 17 (osmotic avoidance abnormal-3) is dispensable for photoreceptor morphology and function. FASEB J 2015; 29:4866-80. [PMID: 26229057 DOI: 10.1096/fj.15-275677] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/27/2015] [Indexed: 01/22/2023]
Abstract
In Caenorhabditis elegans, homodimeric [kinesin family (KIF) 17, osmotic avoidance abnormal-3 (OSM-3)] and heterotrimeric (KIF3) kinesin-2 motors are required to establish sensory cilia by intraflagellar transport (IFT) where KIF3 and KIF17 cooperate to build the axoneme core and KIF17 builds the distal segments. However, the function of KIF17 in vertebrates is unresolved. We expressed full-length and motorless KIF17 constructs in mouse rod photoreceptors using adeno-associated virus in Xenopus laevis rod photoreceptors using a transgene and in ciliated IMCD3 cells. We found that tagged KIF17 localized along the rod outer segment axoneme when expressed in mouse and X. laevis photoreceptors, whereas KIF3A was restricted to the proximal axoneme. Motorless KIF3A and KIF17 mutants caused photoreceptor degeneration, likely through dominant negative effects on IFT. KIF17 mutant lacking the motor domain translocated to nuclei after exposure of a C-terminal nuclear localization signal. Germ-line deletion of Kif17 in mouse did not affect photoreceptor function. A rod-specific Kif3/Kif17 double knockout mouse demonstrated that KIF17 and KIF3 do not act synergistically and did not prevent rhodopsin trafficking to rod outer segments. In summary, the nematode model of KIF3/KIF17 cooperation apparently does not apply to mouse photoreceptors in which the photosensory cilium is built exclusively by KIF3.
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Affiliation(s)
- Li Jiang
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - Beatrice M Tam
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - Guoxing Ying
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - Sen Wu
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - William W Hauswirth
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - Jeanne M Frederick
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - Orson L Moritz
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
| | - Wolfgang Baehr
- *Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, and Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA; and Department of Biology, University of Utah, Salt Lake City, Utah, USA
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21
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Jiang L, Wei Y, Ronquillo CC, Marc RE, Yoder BK, Frederick JM, Baehr W. Heterotrimeric kinesin-2 (KIF3) mediates transition zone and axoneme formation of mouse photoreceptors. J Biol Chem 2015; 290:12765-78. [PMID: 25825494 DOI: 10.1074/jbc.m115.638437] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 11/06/2022] Open
Abstract
Anterograde intraflagellar transport (IFT) employing kinesin-2 molecular motors has been implicated in trafficking of photoreceptor outer segment proteins. We generated embryonic retina-specific (prefix "emb") and adult tamoxifen-induced (prefix "tam") deletions of KIF3a and IFT88 in adult mice to study photoreceptor ciliogenesis and protein trafficking. In (emb)Kif3a(-/-) and in (emb)Ift88(-/-) mice, basal bodies failed to extend transition zones (connecting cilia) with outer segments, and visual pigments mistrafficked. In contrast, (tam)Kif3a(-/-) and (tam)Ift88(-/-) photoreceptor axonemes disintegrated slowly post-induction, starting distally, but rhodopsin and cone pigments trafficked normally for more than 2 weeks, a time interval during which the outer segment is completely renewed. The results demonstrate that visual pigments transport to the retinal outer segment despite removal of KIF3 and IFT88, and KIF3-mediated anterograde IFT is responsible for photoreceptor transition zone and axoneme formation.
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Affiliation(s)
- Li Jiang
- From the Departments of Ophthalmology and Visual Sciences and
| | - Yuxiao Wei
- From the Departments of Ophthalmology and Visual Sciences and
| | | | - Robert E Marc
- From the Departments of Ophthalmology and Visual Sciences and
| | - Bradley K Yoder
- the Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, and
| | | | - Wolfgang Baehr
- From the Departments of Ophthalmology and Visual Sciences and the Department of Biology, University of Utah, Salt Lake City, Utah 84112 Neurobiology and Anatomy, University of Utah Health Science Center, Salt Lake City, Utah 84132,
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22
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Peshenko IV, Olshevskaya EV, Dizhoor AM. Evaluating the role of retinal membrane guanylyl cyclase 1 (RetGC1) domains in binding guanylyl cyclase-activating proteins (GCAPs). J Biol Chem 2015; 290:6913-24. [PMID: 25616661 PMCID: PMC4358116 DOI: 10.1074/jbc.m114.629642] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/21/2015] [Indexed: 12/17/2022] Open
Abstract
Retinal membrane guanylyl cyclase 1 (RetGC1) regulated by guanylyl cyclase-activating proteins (GCAPs) controls photoreceptor recovery and when mutated causes blinding disorders. We evaluated the principal models of how GCAP1 and GCAP2 bind RetGC1: through a shared docking interface versus independent binding sites formed by distant portions of the cyclase intracellular domain. At near-saturating concentrations, GCAP1 and GCAP2 activated RetGC1 from HEK293 cells and RetGC2(-/-)GCAPs1,2(-/-) mouse retinas in a non-additive fashion. The M26R GCAP1, which binds but does not activate RetGC1, suppressed activation of recombinant and native RetGC1 by competing with both GCAP1 and GCAP2. Untagged GCAP1 displaced both GCAP1-GFP and GCAP2-GFP from the complex with RetGC1 in HEK293 cells. The intracellular segment of a natriuretic peptide receptor A guanylyl cyclase failed to bind GCAPs, but replacing its kinase homology and dimerization domains with those from RetGC1 restored GCAP1 and GCAP2 binding by the hybrid cyclase and its GCAP-dependent regulation. Deletion of the Tyr(1016)-Ser(1103) fragment in RetGC1 did not block GCAP2 binding to the cyclase. In contrast, substitutions in the kinase homology domain, W708R and I734T, linked to Leber congenital amaurosis prevented binding of both GCAP1-GFP and GCAP2-GFP. Our results demonstrate that GCAPs cannot regulate RetGC1 using independent primary binding sites. Instead, GCAP1 and GCAP2 bind with the cyclase molecule in a mutually exclusive manner using a common or overlapping binding site(s) in the Arg(488)-Arg(851) portion of RetGC1, and mutations in that region causing Leber congenital amaurosis blindness disrupt activation of the cyclase by both GCAP1 and GCAP2.
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Affiliation(s)
- Igor V Peshenko
- From the Department of Research, Salus University, Elkins Park, Pennsylvania 19027
| | - Elena V Olshevskaya
- From the Department of Research, Salus University, Elkins Park, Pennsylvania 19027
| | - Alexander M Dizhoor
- From the Department of Research, Salus University, Elkins Park, Pennsylvania 19027
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Marc R, Pfeiffer R, Jones B. Retinal prosthetics, optogenetics, and chemical photoswitches. ACS Chem Neurosci 2014; 5:895-901. [PMID: 25089879 PMCID: PMC4210130 DOI: 10.1021/cn5001233] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
![]()
Three
technologies have emerged as therapies to restore light sensing to
profoundly blind patients suffering from late-stage retinal degenerations:
(1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches.
Prosthetics are the most mature and the only approach in clinical
practice. Prosthetic implants require complex surgical intervention
and provide only limited visual resolution but can potentially restore
navigational ability to many blind patients. Optogenetics uses viral
delivery of type 1 opsin genes from prokaryotes or eukaryote algae
to restore light responses in survivor neurons. Targeting and expression
remain major problems, but are potentially soluble. Importantly, optogenetics
could provide the ultimate in high-resolution vision due to the long
persistence of gene expression achieved in animal models. Nevertheless,
optogenetics remains challenging to implement in human eyes with large
volumes, complex disease progression, and physical barriers to viral
penetration. Now, a new generation of photochromic ligands or chemical
photoswitches (azobenzene-quaternary ammonium derivatives) can be
injected into a degenerated mouse eye and, in minutes to hours, activate
light responses in neurons. These photoswitches offer the potential
for rapidly and reversibly screening the vision restoration expected
in an individual patient. Chemical photoswitch variants that persist
in the cell membrane could make them a simple therapy of choice, with
resolution and sensitivity equivalent to optogenetics approaches.
A major complexity in treating retinal degenerations is retinal remodeling:
pathologic network rewiring, molecular reprogramming, and cell death
that compromise signaling in the surviving retina. Remodeling forces
a choice between upstream and downstream targeting, each engaging
different benefits and defects. Prosthetics and optogenetics can be
implemented in either mode, but the use of chemical photoswitches
is currently limited to downstream implementations. Even so, given
the high density of human foveal ganglion cells, the ultimate chemical
photoswitch treatment could deliver cost-effective, high-resolution
vision for the blind.
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Affiliation(s)
- Robert Marc
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah 84132, United States
| | - Rebecca Pfeiffer
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah 84132, United States
| | - Bryan Jones
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah 84132, United States
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Tran NM, Chen S. Mechanisms of blindness: animal models provide insight into distinct CRX-associated retinopathies. Dev Dyn 2014; 243:1153-66. [PMID: 24888636 DOI: 10.1002/dvdy.24151] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/24/2014] [Accepted: 05/10/2014] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The homeodomain transcription factor CRX is a crucial regulator of mammalian photoreceptor gene expression. Mutations in the human CRX gene are associated with dominant inherited retinopathies Retinitis Pigmentosa (RP), Cone-Rod Dystrophy (CoRD), and Leber Congenital Amaurosis (LCA), of varying severity. In vitro and in vivo assessment of mutant CRX proteins have revealed pathogenic mechanisms for several mutations, but no comprehensive mutation-disease correlation has yet been reported. RESULTS Here we describe four different classes of disease-causing CRX mutations, characterized by mutation type, pathogenetic mechanism, and the molecular activity of the mutant protein: (1) hypomorphic missense mutations with reduced DNA binding, (2) antimorphic missense mutations with variable DNA binding, (3) antimorphic frameshift/nonsense mutations with intact DNA binding, and (4) antimorphic frameshift mutations with reduced DNA binding. Mammalian models representing three of these classes have been characterized. CONCLUSIONS Models carrying Class I mutations display a mild dominant retinal phenotype and recessive LCA, while models carrying Class III and IV mutations display characteristically distinct dominant LCA phenotypes. These animal models also reveal unexpected pathogenic mechanisms underlying CRX-associated retinopathies. The complexity of genotype-phenotype correlation for CRX-associated diseases highlights the value of developing comprehensive "true-to-disease" animal models for understanding pathologic mechanisms and testing novel therapeutic approaches.
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Affiliation(s)
- Nicholas M Tran
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri
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25
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Centrin 2 is required for mouse olfactory ciliary trafficking and development of ependymal cilia planar polarity. J Neurosci 2014; 34:6377-88. [PMID: 24790208 DOI: 10.1523/jneurosci.0067-14.2014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Centrins are ancient calmodulin-related Ca(2+)-binding proteins associated with basal bodies. In lower eukaryotes, Centrin2 (CETN2) is required for basal body replication and positioning, although its function in mammals is undefined. We generated a germline CETN2 knock-out (KO) mouse presenting with syndromic ciliopathy including dysosmia and hydrocephalus. Absence of CETN2 leads to olfactory cilia loss, impaired ciliary trafficking of olfactory signaling proteins, adenylate cyclase III (ACIII), and cyclic nucleotide-gated (CNG) channel, as well as disrupted basal body apical migration in postnatal olfactory sensory neurons (OSNs). In mutant OSNs, cilia base-anchoring of intraflagellar transport components IFT88, the kinesin-II subunit KIF3A, and cytoplasmic dynein 2 appeared compromised. Although the densities of mutant ependymal and respiratory cilia were largely normal, the planar polarity of mutant ependymal cilia was disrupted, resulting in uncoordinated flow of CSF. Transgenic expression of GFP-CETN2 rescued the Cetn2-deficiency phenotype. These results indicate that mammalian basal body replication and ciliogenesis occur independently of CETN2; however, mouse CETN2 regulates protein trafficking of olfactory cilia and participates in specifying planar polarity of ependymal cilia.
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Roosing S, Thiadens AAHJ, Hoyng CB, Klaver CCW, den Hollander AI, Cremers FPM. Causes and consequences of inherited cone disorders. Prog Retin Eye Res 2014; 42:1-26. [PMID: 24857951 DOI: 10.1016/j.preteyeres.2014.05.001] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 04/29/2014] [Accepted: 05/06/2014] [Indexed: 11/18/2022]
Abstract
Hereditary cone disorders (CDs) are characterized by defects of the cone photoreceptors or retinal pigment epithelium underlying the macula, and include achromatopsia (ACHM), cone dystrophy (COD), cone-rod dystrophy (CRD), color vision impairment, Stargardt disease (STGD) and other maculopathies. Forty-two genes have been implicated in non-syndromic inherited CDs. Mutations in the 5 genes implicated in ACHM explain ∼93% of the cases. On the contrary, only 21% of CRDs (17 genes) and 25% of CODs (8 genes) have been elucidated. The fact that the large majority of COD and CRD-associated genes are yet to be discovered hints towards the existence of unknown cone-specific or cone-sensitive processes. The ACHM-associated genes encode proteins that fulfill crucial roles in the cone phototransduction cascade, which is the most frequently compromised (10 genes) process in CDs. Another 7 CD-associated proteins are required for transport processes towards or through the connecting cilium. The remaining CD-associated proteins are involved in cell membrane morphogenesis and maintenance, synaptic transduction, and the retinoid cycle. Further novel genes are likely to be identified in the near future by combining large-scale DNA sequencing and transcriptomics technologies. For 31 of 42 CD-associated genes, mammalian models are available, 14 of which have successfully been used for gene augmentation studies. However, gene augmentation for CDs should ideally be developed in large mammalian models with cone-rich areas, which are currently available for only 11 CD genes. Future research will aim to elucidate the remaining causative genes, identify the molecular mechanisms of CD, and develop novel therapies aimed at preventing vision loss in individuals with CD in the future.
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Affiliation(s)
- Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | | | - Carel B Hoyng
- Department of Ophthalmology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Caroline C W Klaver
- Department of Ophthalmology Erasmus Medical Centre, 3000 CA, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus Medical Centre, 3000 CA, Rotterdam, The Netherlands
| | - Anneke I den Hollander
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Department of Ophthalmology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
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27
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Yan B, Yao J, Tao ZF, Jiang Q. Epigenetics and ocular diseases: from basic biology to clinical study. J Cell Physiol 2014; 229:825-33. [PMID: 24318407 DOI: 10.1002/jcp.24522] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 12/02/2013] [Indexed: 12/23/2022]
Abstract
Epigenetics is an emerging field in ophthalmology and has opened a new avenue for understanding ocular development and ocular diseases related to aging and environment. Epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and deployment of non-coding RNAs, result in the heritable silencing of gene expression without any change in DNA sequence. Accumulating evidence suggests a potential link between gene expression, chromatin structure, non-coding RNAs, and cellular differentiation during ocular development. Disruption of the balance of epigenetic networks could become the etiology of several ocular diseases. Here, we summarized the current knowledge about epigenetic regulatory mechanisms in ocular development and diseases.
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Affiliation(s)
- Biao Yan
- Eye Hospital, Nanjing Medical University, Nanjing, China
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28
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Jiang L, Frederick JM, Baehr W. RNA interference gene therapy in dominant retinitis pigmentosa and cone-rod dystrophy mouse models caused by GCAP1 mutations. Front Mol Neurosci 2014; 7:25. [PMID: 24778606 PMCID: PMC3985072 DOI: 10.3389/fnmol.2014.00025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 03/19/2014] [Indexed: 12/26/2022] Open
Abstract
RNA interference (RNAi) knockdown is an efficacious therapeutic strategy for silencing genes causative for dominant retinal dystrophies. To test this, we used self-complementary (sc) AAV2/8 vector to develop an RNAi-based therapy in two dominant retinal degeneration mouse models. The allele-specific model expresses transgenic bovine GCAP1(Y99C) establishing a rapid RP-like phenotype, whereas the nonallele-specific model expresses mouse GCAP1(L151F) producing a slowly progressing cone-rod dystrophy (CORD). The late onset GCAP1(L151F)-CORD mimics the dystrophy observed in human GCAP1-CORD patients. Subretinal injection of scAAV2/8 carrying shRNA expression cassettes specific for bovine or mouse guanylate cyclase-activating protein 1 (GCAP1) showed strong expression at 1 week post-injection. In both allele-specific [GCAP1(Y99C)-RP] and nonallele-specific [GCAP1(L151F)-CORD] models of dominant retinal dystrophy, RNAi-mediated gene silencing enhanced photoreceptor survival, delayed onset of degeneration and improved visual function. Such results provide a "proof of concept" toward effective RNAi-based gene therapy mediated by scAAV2/8 for dominant retinal disease based on GCAP1 mutation. Further, nonallele-specific RNAi knockdown of GCAP1 may prove generally applicable toward the rescue of any human GCAP1-based dominant cone-rod dystrophy.
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Affiliation(s)
- Li Jiang
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah Health Science Center Salt Lake City, UT, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah Health Science Center Salt Lake City, UT, USA
| | - Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah Health Science Center Salt Lake City, UT, USA ; Department of Biology, University of Utah Salt Lake City, UT, USA ; Department of Neurobiology and Anatomy, University of Utah Health Science Center Salt Lake City, UT, USA
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29
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Peshenko IV, Olshevskaya EV, Lim S, Ames JB, Dizhoor AM. Identification of target binding site in photoreceptor guanylyl cyclase-activating protein 1 (GCAP1). J Biol Chem 2014; 289:10140-54. [PMID: 24567338 PMCID: PMC3974984 DOI: 10.1074/jbc.m113.540716] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 02/10/2014] [Indexed: 12/21/2022] Open
Abstract
Retinal guanylyl cyclase (RetGC)-activating proteins (GCAPs) regulate visual photoresponse and trigger congenital retinal diseases in humans, but GCAP interaction with its target enzyme remains obscure. We mapped GCAP1 residues comprising the RetGC1 binding site by mutagenizing the entire surface of GCAP1 and testing the ability of each mutant to bind RetGC1 in a cell-based assay and to activate it in vitro. Mutations that most strongly affected the activation of RetGC1 localized to a distinct patch formed by the surface of non-metal-binding EF-hand 1, the loop and the exiting helix of EF-hand 2, and the entering helix of EF-hand 3. Mutations in the binding patch completely blocked activation of the cyclase without affecting Ca(2+) binding stoichiometry of GCAP1 or its tertiary fold. Exposed residues in the C-terminal portion of GCAP1, including EF-hand 4 and the helix connecting it with the N-terminal lobe of GCAP1, are not critical for activation of the cyclase. GCAP1 mutants that failed to activate RetGC1 in vitro were GFP-tagged and co-expressed in HEK293 cells with mOrange-tagged RetGC1 to test their direct binding in cyto. Most of the GCAP1 mutations introduced into the "binding patch" prevented co-localization with RetGC1, except for Met-26, Lys-85, and Trp-94. With these residues mutated, GCAP1 completely failed to stimulate cyclase activity but still bound RetGC1 and competed with the wild type GCAP1. Thus, RetGC1 activation by GCAP1 involves establishing a tight complex through the binding patch with an additional activation step involving Met-26, Lys-85, and Trp-94.
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Affiliation(s)
- Igor V. Peshenko
- From the Department of Basic Sciences and the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027 and
| | - Elena V. Olshevskaya
- From the Department of Basic Sciences and the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027 and
| | - Sunghyuk Lim
- the Department of Chemistry, University of California, Davis, California 95616
| | - James B. Ames
- the Department of Chemistry, University of California, Davis, California 95616
| | - Alexander M. Dizhoor
- From the Department of Basic Sciences and the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027 and
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30
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Zägel P, Koch KW. Dysfunction of outer segment guanylate cyclase caused by retinal disease related mutations. Front Mol Neurosci 2014; 7:4. [PMID: 24616660 PMCID: PMC3935488 DOI: 10.3389/fnmol.2014.00004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 02/10/2014] [Indexed: 11/13/2022] Open
Abstract
Membrane bound guanylate cyclases are expressed in rod and cone cells of the vertebrate retina and mutations in several domains of rod outer segment guanylate cyclase 1 (ROS-GC1 encoded by the gene GUCY2D) correlate with different forms of retinal degenerations. In the present work we investigated the biochemical consequences of three point mutations, one is located in position P575L in the juxtamembrane domain close to the kinase homology domain and two are located in the cyclase catalytic domain at H1019P and P1069R. These mutations correlate with various retinal diseases like autosomal dominant progressive cone degeneration, e.g., Leber Congenital Amaurosis and a juvenile form of retinitis pigmentosa. Wildtype and mutant forms of ROS-GC1 were heterologously expressed in HEK cells, their cellular distribution was investigated and activity profiles in the presence and absence of guanylate cyclase-activating proteins were measured. The mutant P575L was active under all tested conditions, but it displayed a twofold shift in the Ca2+-sensitivity, whereas the mutant P1069R remained inactive despite normal expression levels. The mutation H1019P caused the cyclase to become more labile. The different biochemical consequences of these mutations seem to reflect the different clinical symptoms. The mutation P575L induces a dysregulation of the Ca2+-sensitive cyclase activation profile causing a slow progression of the disease by the distortion of the Ca2+-cGMP homeostasis. In contrast, a strong reduction in cGMP synthesis due to an inactive or structurally unstable ROS-GC1 would trigger more severe forms of retinal diseases.
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Affiliation(s)
- Patrick Zägel
- Biochemistry Group, Department of Neurosciences, Carl von Ossietzky University Oldenburg Oldenburg, Germany
| | - Karl-Wilhelm Koch
- Biochemistry Group, Department of Neurosciences, Carl von Ossietzky University Oldenburg Oldenburg, Germany ; Research Center Neurosensory Science, Carl von Ossietzky University Oldenburg Oldenburg, Germany
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31
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RNAi-mediated knockdown of IKK1 in transgenic mice using a transgenic construct containing the human H1 promoter. ScientificWorldJournal 2014; 2014:193803. [PMID: 24523631 PMCID: PMC3913291 DOI: 10.1155/2014/193803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/12/2013] [Indexed: 01/16/2023] Open
Abstract
Inhibition of gene expression through siRNAs is a tool increasingly used for the study of gene function in model systems, including transgenic mice. To achieve perdurable effects, the stable expression of siRNAs by an integrated transgenic construct is necessary. For transgenic siRNA expression, promoters transcribed by either RNApol II or III (such as U6 or H1 promoters) can be used. Relatively large amounts of small RNAs synthesis are achieved when using RNApol III promoters, which can be advantageous in knockdown experiments. To study the feasibility of H1 promoter-driven RNAi-expressing constructs for protein knockdown in transgenic mice, we chose IKK1 as the target gene. Our results indicate that constructs containing the H1 promoter are sensitive to the presence of prokaryotic sequences and to transgene position effects, similar to RNApol II promoters-driven constructs. We observed variable expression levels of transgenic siRNA among different tissues and animals and a reduction of up to 80% in IKK1 expression. Furthermore, IKK1 knockdown led to hair follicle alterations. In summary, we show that constructs directed by the H1 promoter can be used for knockdown of genes of interest in different organs and for the generation of animal models complementary to knockout and overexpression models.
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32
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Zhang H, Frederick JM, Baehr W. Unc119 gene deletion partially rescues the GRK1 transport defect of Pde6d (- /-) cones. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:487-93. [PMID: 24664735 DOI: 10.1007/978-1-4614-3209-8_62] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PrBP/δ, encoded by the Pde6d gene, is an isoprenyl-binding protein that regulates trafficking of isoprenylated proteins, such as PDE6 and GRK1, from photoreceptor inner segments to outer segments. Trafficking of PDE6 and GRK1 to photoreceptor outer segments is impeded in Pde6d knockout mice. In Pde6d (-/-) cones, PDE6 and GRK1 are nearly undetectable and the b-wave amplitudes of photopic ERGs in Pde6d (-/-) mice are reduced by over 50 %. We reported recently that UNC119, a homolog of PrBP/δ highly expressed in photoreceptors, functions as an acyl-binding protein and regulates transport of G-proteins in sensory neurons. Since both PrBP/δ and UNC119 regulate peripheral protein trafficking in photoreceptors, we generated Pde6d; Unc119 double knockout mice in order to study how PrBP/δ and UNC119 may interact. Surprisingly, knockout of Unc119 partially reversed the transport defect of GRK1 in cone photoreceptors caused by deletion of Pde6d, and the b-wave amplitudes of photopic ERGs in the double knockout mice were significantly higher than those in the Pde6d (-/-) mice. These results suggest that cone transport of isoprenylated and acylated proteins is interdependent.
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Affiliation(s)
- Houbin Zhang
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, 65 Mario Capecchi Drive, 84132, Salt Lake City, UT, USA,
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cGMP accumulation causes photoreceptor degeneration in CNG channel deficiency: evidence of cGMP cytotoxicity independently of enhanced CNG channel function. J Neurosci 2013; 33:14939-48. [PMID: 24027293 DOI: 10.1523/jneurosci.0909-13.2013] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Photoreceptor cyclic nucleotide-gated (CNG) channels regulate Ca(2+) influx in rod and cone photoreceptors. cGMP, the native ligand of the photoreceptor CNG channels, has been associated with cytotoxicity when its levels rise above normal due to defects in photoreceptor phosphodiesterase (PDE6) or regulation of retinal guanylyl cyclase (retGC). We found a massive accumulation of cGMP in CNGA3-deficient retina and investigated whether cGMP accumulation plays a role in cone degeneration in CNG channel deficiency. The time course study showed that the retinal cGMP level in Cnga3(-/-);Nrl(-/-) mice with CNGA3 deficiency on a cone-dominant background was sharply increased at postnatal day 8 (P8), peaked around P10-P15, remained high through P30-P60, and returned to near control level at P90. This elevation pattern correlated with photoreceptor apoptotic death, which peaked around P15-P20. In Cnga3(-/-);Gucy2e(-/-) mice lacking retGC1, cone density and expression levels of cone-specific proteins were significantly increased compared with Cnga3(-/-), consistent with a role of cGMP accumulation as the major contributor to cone death caused by CNG channel deficiency. The activity and expression levels of cGMP-dependent protein kinase G (PKG) were significantly increased in Cnga3(-/-);Nrl(-/-) retina compared with Nrl(-/-), suggesting an involvement of PKG regulation in cell death. Our results indicate that cGMP accumulation in photoreceptors can itself exert cytotoxic effect in cones, independently of CNG channel activity and Ca(2+) influx.
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34
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Structural insights for activation of retinal guanylate cyclase by GCAP1. PLoS One 2013; 8:e81822. [PMID: 24236217 PMCID: PMC3827477 DOI: 10.1371/journal.pone.0081822] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/27/2013] [Indexed: 01/24/2023] Open
Abstract
Guanylyl cyclase activating protein 1 (GCAP1), a member of the neuronal calcium sensor (NCS) subclass of the calmodulin superfamily, confers Ca(2+)-sensitive activation of retinal guanylyl cyclase 1 (RetGC1) upon light activation of photoreceptor cells. Here we present NMR assignments and functional analysis to probe Ca(2+)-dependent structural changes in GCAP1 that control activation of RetGC. NMR assignments were obtained for both the Ca(2+)-saturated inhibitory state of GCAP1 versus a GCAP1 mutant (D144N/D148G, called EF4mut), which lacks Ca(2+) binding in EF-hand 4 and models the Ca(2+)-free/Mg(2+)-bound activator state of GCAP1. NMR chemical shifts of backbone resonances for Ca(2+)-saturated wild type GCAP1 are overall similar to those of EF4mut, suggesting a similar main chain structure for assigned residues in both the Ca(2+)-free activator and Ca(2+)-bound inhibitor states. This contrasts with large Ca(2+)-induced chemical shift differences and hence dramatic structural changes seen for other NCS proteins including recoverin and NCS-1. The largest chemical shift differences between GCAP1 and EF4mut are seen for residues in EF4 (S141, K142, V145, N146, G147, G149, E150, L153, E154, M157, E158, Q161, L166), but mutagenesis of EF4 residues (F140A, K142D, L153R, L166R) had little effect on RetGC1 activation. A few GCAP1 residues in EF-hand 1 (K23, T27, G32) also show large chemical shift differences, and two of the mutations (K23D and G32N) each decrease the activation of RetGC, consistent with a functional conformational change in EF1. GCAP1 residues at the domain interface (V77, A78, L82) have NMR resonances that are exchange broadened, suggesting these residues may be conformationally dynamic, consistent with previous studies showing these residues are in a region essential for activating RetGC1.
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Bordignon V, El-Beirouthi N, Gasperin BG, Albornoz MS, Martinez-Diaz MA, Schneider C, Laurin D, Zadworny D, Agellon LB. Production of cloned pigs with targeted attenuation of gene expression. PLoS One 2013; 8:e64613. [PMID: 23737990 PMCID: PMC3667777 DOI: 10.1371/journal.pone.0064613] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/16/2013] [Indexed: 12/20/2022] Open
Abstract
The objective of this study was to demonstrate that RNA interference (RNAi) and somatic cell nuclear transfer (SCNT) technologies can be used to attenuate the expression of specific genes in tissues of swine, a large animal species. Apolipoprotein E (apoE), a secreted glycoprotein known for its major role in lipid and lipoprotein metabolism and transport, was selected as the target gene for this study. Three synthetic small interfering RNAs (siRNA) targeting the porcine apoE mRNA were tested in porcine granulosa cells in primary culture and reduced apoE mRNA abundance ranging from 45-82% compared to control cells. The most effective sequence was selected for cloning into a short hairpin RNA (shRNA) expression vector under the control of RNA polymerase III (U6) promoter. Stably transfected fetal porcine fibroblast cells were generated and used to produce embryos with in vitro matured porcine oocytes, which were then transferred into the uterus of surrogate gilts. Seven live and one stillborn piglet were born from three gilts that became pregnant. Integration of the shRNA expression vector into the genome of clone piglets was confirmed by PCR and expression of the GFP transgene linked to the expression vector. Analysis showed that apoE protein levels in the liver and plasma of the clone pigs bearing the shRNA expression vector targeting the apoE mRNA was significantly reduced compared to control pigs cloned from non-transfected fibroblasts of the same cell line. These results demonstrate the feasibility of applying RNAi and SCNT technologies for introducing stable genetic modifications in somatic cells for eventual attenuation of gene expression in vivo in large animal species.
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Affiliation(s)
| | | | | | | | | | | | - Denyse Laurin
- Department of Animal Science, McGill University, Quebec, Canada
| | - David Zadworny
- Department of Animal Science, McGill University, Quebec, Canada
| | - Luis B. Agellon
- School of Dietetics and Human Nutrition, McGill University, Quebec, Canada
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Simonato M, Bennett J, Boulis NM, Castro MG, Fink DJ, Goins WF, Gray SJ, Lowenstein PR, Vandenberghe LH, Wilson TJ, Wolfe JH, Glorioso JC. Progress in gene therapy for neurological disorders. Nat Rev Neurol 2013; 9:277-91. [PMID: 23609618 PMCID: PMC3908892 DOI: 10.1038/nrneurol.2013.56] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Diseases of the nervous system have devastating effects and are widely distributed among the population, being especially prevalent in the elderly. These diseases are often caused by inherited genetic mutations that result in abnormal nervous system development, neurodegeneration, or impaired neuronal function. Other causes of neurological diseases include genetic and epigenetic changes induced by environmental insults, injury, disease-related events or inflammatory processes. Standard medical and surgical practice has not proved effective in curing or treating these diseases, and appropriate pharmaceuticals do not exist or are insufficient to slow disease progression. Gene therapy is emerging as a powerful approach with potential to treat and even cure some of the most common diseases of the nervous system. Gene therapy for neurological diseases has been made possible through progress in understanding the underlying disease mechanisms, particularly those involving sensory neurons, and also by improvement of gene vector design, therapeutic gene selection, and methods of delivery. Progress in the field has renewed our optimism for gene therapy as a treatment modality that can be used by neurologists, ophthalmologists and neurosurgeons. In this Review, we describe the promising gene therapy strategies that have the potential to treat patients with neurological diseases and discuss prospects for future development of gene therapy.
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Affiliation(s)
- Michele Simonato
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara, Fossato di Mortara 17-19, 44121 Ferrara, Italy. michele.simonato@ unife.it
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Jiang L, Li TZ, Boye SE, Hauswirth WW, Frederick JM, Baehr W. RNAi-mediated gene suppression in a GCAP1(L151F) cone-rod dystrophy mouse model. PLoS One 2013; 8:e57676. [PMID: 23472098 PMCID: PMC3589431 DOI: 10.1371/journal.pone.0057676] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 01/23/2013] [Indexed: 12/22/2022] Open
Abstract
Dominant mutations occurring in the high-affinity Ca(2+)-binding sites (EF-hands) of the GUCA1A gene encoding guanylate cyclase-activating protein 1 (GCAP1) cause slowly progressing cone-rod dystrophy (CORD) in a dozen families worldwide. We developed a nonallele-specific adeno-associated virus (AAV)-based RNAi knockdown strategy to rescue the retina degeneration caused by GCAP1 mutations. We generated three genomic transgenic mouse lines expressing wildtype (WT) and L151F mutant mouse GCAP1 with or without a C-terminal GFP fusion. Under control of endogenous regulatory elements, the transgenes were expressed specifically in mouse photoreceptors. GCAP1(L151F) and GCAP1(L151F)-GFP transgenic mice presented with a late onset and slowly progressive photoreceptor degeneration, similar to that observed in human GCAP1-CORD patients. Transgenic expression of WT GCAP1-EGFP in photoreceptors had no adverse effect. Toward therapy development, a highly effective anti-mGCAP1 shRNA, mG1hp4, was selected from four candidate shRNAs using an in-vitro screening assay. Subsequently a self-complementary (sc) AAV serotype 2/8 expressing mG1hp4 was delivered subretinally to GCAP1(L151F)-GFP transgenic mice. Knockdown of the GCAP1(L151F)-GFP transgene product was visualized by fluorescence live imaging in the scAAV2/8-mG1hp4-treated retinas. Concomitant with the mutant GCAP1-GFP fusion protein, endogenous GCAP1 decreased as well in treated retinas. We propose nonallele-specific RNAi knockdown of GCAP1 as a general therapeutic strategy to rescue any GCAP1-based dominant cone-rod dystrophy in human patients.
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Affiliation(s)
- Li Jiang
- Department of Ophthalmology and Visual Sciences, University of Utah Health Science Center, Salt Lake City, Utah, United States of America
| | - Tansy Z. Li
- Department of Ophthalmology and Visual Sciences, University of Utah Health Science Center, Salt Lake City, Utah, United States of America
| | - Shannon E. Boye
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - William W. Hauswirth
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States of America
| | - Jeanne M. Frederick
- Department of Ophthalmology and Visual Sciences, University of Utah Health Science Center, Salt Lake City, Utah, United States of America
| | - Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah Health Science Center, Salt Lake City, Utah, United States of America
- Department of Biology, University of Utah, Salt Lake City, Utah, United States of America
- Department of Neurobiology and Anatomy, University of Utah Health Science Center, Salt Lake City Utah, United States of America
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Current world literature. Curr Opin Pediatr 2012; 24:770-9. [PMID: 23146873 DOI: 10.1097/mop.0b013e32835af8de] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Retinal guanylyl cyclase isozyme 1 is the preferential in vivo target for constitutively active GCAP1 mutants causing congenital degeneration of photoreceptors. J Neurosci 2012; 32:7208-17. [PMID: 22623665 DOI: 10.1523/jneurosci.0976-12.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Two calcium-sensitive guanylyl cyclase activating proteins (GCAP1 and GCAP2) activate cGMP synthesis in photoreceptor by retinal membrane guanylyl cyclase isozymes (RetGC1 and RetGC2) to expedite recovery, but calcium-insensitive constitutively active GCAP1 mutants cause photoreceptor degeneration in human patients and transgenic mice. Although GCAP1 and GCAP2 can both activate RetGC1 and RetGC2 in vitro, we find that GCAP1 selectively regulates RetGC1 in vivo. Furthermore, elimination of RetGC1 but not RetGC2 isozyme reverses abnormal calcium sensitivity of cGMP synthesis and rescues mouse rods in transgenic mice expressing GCAP1 mutants causing photoreceptor disease. Rods expressing mutant GCAP1 not only survive in the absence of RetGC1 but also remain functional, albeit with reduced electroretinography (ERG) amplitudes typical of RetGC1-/- genotype. The rod ERG recovery from a strong flash, only slightly affected in both RetGC1-/- and RetGC2-/- mice, becomes very slow in RetGC1-/- but not RetGC2-/- mice when GCAP2 is not available to provide Ca²⁺ feedback to the remaining RetGC isozyme. The intrinsic biochemical properties of RetGC and GCAP determined in vitro do not explain the observed phenomena. Instead, our results argue that there must be a cellular mechanism that limits GCAP1 access to RetGC2 and makes RetGC1 isozyme a preferential target for the disease-causing GCAP1 mutants. A more general conclusion from our findings is that nondiscriminatory interactions between homologous effector enzymes and their regulatory proteins permitted by their intrinsic biochemical properties can be effectively restricted in a living photoreceptor.
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Peshenko IV, Olshevskaya EV, Lim S, Ames JB, Dizhoor AM. Calcium-myristoyl Tug is a new mechanism for intramolecular tuning of calcium sensitivity and target enzyme interaction for guanylyl cyclase-activating protein 1: dynamic connection between N-fatty acyl group and EF-hand controls calcium sensitivity. J Biol Chem 2012; 287:13972-84. [PMID: 22383530 DOI: 10.1074/jbc.m112.341883] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Guanylyl cyclase-activating protein 1 (GCAP1), a myristoylated Ca(2+) sensor in vision, regulates retinal guanylyl cyclase (RetGC). We show that protein-myristoyl group interactions control Ca(2+) sensitivity, apparent affinity for RetGC, and maximal level of cyclase activation. Mutating residues near the myristoyl moiety affected the affinity of Ca(2+) binding to EF-hand 4. Inserting Phe residues in the cavity around the myristoyl group increased both the affinity of GCAP1 for RetGC and maximal activation of the cyclase. NMR spectra show that the myristoyl group in the L80F/L176F/V180F mutant remained sequestered inside GCAP1 in both Ca(2+)-bound and Mg(2+)-bound states. This mutant displayed much higher affinity for the cyclase but reduced Ca(2+) sensitivity of the cyclase regulation. The L176F substitution improved affinity of myristoylated and non-acylated GCAP1 for the cyclase but simultaneously reduced the affinity of Ca(2+) binding to EF-hand 4 and Ca(2+) sensitivity of the cyclase regulation by acylated GCAP1. The replacement of amino acids near both ends of the myristoyl moiety (Leu(80) and Val(180)) minimally affected regulatory properties of GCAP1. N-Lauryl- and N-myristoyl-GCAP1 activated RetGC in a similar fashion. Thus, protein interactions with the central region of the fatty acyl chain optimize GCAP1 binding to RetGC and maximize activation of the cyclase. We propose a dynamic connection (or "tug") between the fatty acyl group and EF-hand 4 via the C-terminal helix that attenuates the efficiency of RetGC activation in exchange for optimal Ca(2+) sensitivity.
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Affiliation(s)
- Igor V Peshenko
- Department of Basic Sciences and Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027, USA
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