1
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Huang XX, Wang YM, Xie MY, Sun YQ, Zhao XH, Chen YH, Chen JQ, Han SY, Zhou MW, Sun XD. Publication trends of Leber congenital amaurosis researches: a bibliometric study during 2002-2022. Int J Ophthalmol 2024; 17:1501-1509. [PMID: 39156783 PMCID: PMC11286431 DOI: 10.18240/ijo.2024.08.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 04/12/2024] [Indexed: 08/20/2024] Open
Abstract
AIM To analyze the changes in scientific output relating to Leber congenital amaurosis (LCA) and forecast the study trends in this field. METHODS All of the publications in the field of LCA from 2002 to 2022 were collected from Web of Science (WOS) database. We analyzed the quantity (number of publications), quality (citation and H-index) and development trends (relative research interest, RRI) of published LCA research over the last two decades. Moreover, VOSviewer software was applied to define the co-occurrence network of keywords in this field. RESULTS A total of 2158 publications were ultimately examined. We found that the focus on LCA kept rising and peaked in 2015 and 2018, which is consistent with the development trend of gene therapy. The USA has contributed most to this field with 1162 publications, 56 674 citations and the highest H-index value (116). The keywords analysis was divided into five clusters to show the hotspots in the field of LCA, namely mechanism-related, genotype-related, local phenotype-related, system phenotype-related, and therapy-related. We also identified gene therapy and anti-retinal degeneration therapy as a major focus in recent years. CONCLUSION Our study illustrates historical research process and future development trends in LCA field. This may help to guide the orientation for further clinical diagnosis, treatment and scientific research.
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Affiliation(s)
- Xiao-Xu Huang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
- National Clinical Research Center for Eye Disease, Shanghai 200080, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
| | - Yi-Min Wang
- Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai 200030, China
| | - Min-Yue Xie
- Beijing Tongren Hospital, Capital Medical University, Beijing 100054, China
| | - Yi-Qing Sun
- Eberly College of Science, Penn State University, University Park 16802-1503, United States
| | - Xiao-Huan Zhao
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
- National Clinical Research Center for Eye Disease, Shanghai 200080, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
| | - Yu-Hong Chen
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
- National Clinical Research Center for Eye Disease, Shanghai 200080, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
| | - Jie-Qiong Chen
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
- National Clinical Research Center for Eye Disease, Shanghai 200080, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
| | - Si-Yang Han
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
- National Clinical Research Center for Eye Disease, Shanghai 200080, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
| | - Min-Wen Zhou
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
- National Clinical Research Center for Eye Disease, Shanghai 200080, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
| | - Xiao-Dong Sun
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
- National Clinical Research Center for Eye Disease, Shanghai 200080, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
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2
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Kamde SP, Anjankar A. Retinitis Pigmentosa: Pathogenesis, Diagnostic Findings, and Treatment. Cureus 2023; 15:e48006. [PMID: 38034182 PMCID: PMC10686897 DOI: 10.7759/cureus.48006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Retinitis Pigmentosa (RP) is an inherited retinal dystrophy (IRD) that causes progressive visual loss. Patients suffering from RP have a substantial influence on their everyday activities, social contacts, and jobs, lowering their quality of life. Frequent referral delays, as well as the lack of a standard therapy for the majority of patients, contribute to the significant unmet demand for RP. Any retinal injury has the potential to result in total blindness and visual impairment. Despite the fact that there is no cure for RP, people can manage it using rehabilitation programs and low-vision gadgets. The purpose of this research is to characterize the expanding treatment landscape for RP, as well as the justification for advanced therapy medicinal products (ATMPs). Vitamin A supplements can help prevent the sluggish visual loss caused by a prevalent kind of RP. The presence of visual purple in the rods and the underlying vascular choroid causes the retina to look purplish red. The major portion of the retina damaged is the rod photoreceptor electric cell; the development of diverse diseases is progressive. Because of the retina's accessibility, immunological privilege, and compartmentalization, hereditary retinal diseases are amenable to cell and gene therapy. Therapeutic techniques that attempt to rescue photoreceptors (gene therapies) require the existence of non-functional target cells, but other therapies (cell therapies) do not require the presence of live photoreceptors. To provide successful therapy choices for RP patients at all disease phases, the development pipeline must be continually diversified and advanced, as well as ongoing efforts to encourage early patient identification and quick diagnosis. Future research will focus on avoiding vision loss in genetic eye illnesses and assisting patients in regaining their eyesight. Retinal implants, cell therapies, supplementary medications, and gene therapies may become common treatments for reducing vision loss in the future.
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Affiliation(s)
- Saakshi P Kamde
- Forensic Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Anil Anjankar
- Forensic Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
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3
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Lee LMY, Leung YC, Shum ASW. Hyperglycemia alters retinoic acid catabolism in embryos exposed to a maternal diabetic milieu. PLoS One 2023; 18:e0287253. [PMID: 37616226 PMCID: PMC10449132 DOI: 10.1371/journal.pone.0287253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/01/2023] [Indexed: 08/26/2023] Open
Abstract
Pregestational diabetes is highly associated with increased risk of birth defects. We previously reported that the expression of Cyp26a1, the major catabolizing enzyme for controlling retinoic acid (RA) homeostasis, is significantly down-regulated in embryos of diabetic mice, thereby increasing the embryo's susceptibility to malformations caused by RA dysregulation. However, the underlying mechanism for the down-regulation of Cyp26a1 remains unclear. This study aimed to investigate whether elevated maternal blood glucose in the diabetic milieu is a critical factor for the altered Cyp26a1 expression. Streptozotozin-induced diabetic pregnant mice were treated with phlorizin (PHZ) to reduce blood glucose concentrations via induction of renal glucosuria. Embryonic Cyp26a1 expression level, RA catabolic activity and susceptibility to various RA-induced abnormalities were examined. To test the dose-dependent effect of glucose on Cyp26a1 level, early head-fold stage rat embryos of normal pregnancy were cultured in vitro with varying concentrations of D-glucose, followed by quantification of Cyp26a1 transcripts. We found that Cyp26a1 expression, which was down-regulated in diabetic pregnancy, could be normalized under reduced maternal blood glucose level, concomitant with an increase in RA catabolic activity in embryonic tissues. Such normalization could successfully reduce the susceptibility to different RA-induced malformations including caudal regression, cleft palate and renal malformations. The expression level of Cyp26a1 in the embryo was inversely correlated with D-glucose concentrations. Diabetic patients suffer from retinopathy, dermopathy, male infertility and increased cancer risk. Coincidentally, RA dysregulation is also associated with these health problems. Our results provided evidence that elevated glucose can down-regulate Cyp26a1 expression level and disturb RA homeostasis, shedding light on the possibility of affecting the health of diabetic patients via a similar mechanism.
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Affiliation(s)
- Leo Man Yuen Lee
- Department of Applied Biology and Chemical Technology, Lo Ka Chung Research Centre for Natural Anti-Cancer Drug Development and State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong, Hong Kong
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Yun-chung Leung
- Department of Applied Biology and Chemical Technology, Lo Ka Chung Research Centre for Natural Anti-Cancer Drug Development and State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Hong Kong, Hong Kong
| | - Alisa Sau Wun Shum
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong
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4
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Karamali F, Behtaj S, Babaei-Abraki S, Hadady H, Atefi A, Savoj S, Soroushzadeh S, Najafian S, Nasr Esfahani MH, Klassen H. Potential therapeutic strategies for photoreceptor degeneration: the path to restore vision. J Transl Med 2022; 20:572. [PMID: 36476500 PMCID: PMC9727916 DOI: 10.1186/s12967-022-03738-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/29/2022] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors (PRs), as the most abundant and light-sensing cells of the neuroretina, are responsible for converting light into electrical signals that can be interpreted by the brain. PR degeneration, including morphological and functional impairment of these cells, causes significant diminution of the retina's ability to detect light, with consequent loss of vision. Recent findings in ocular regenerative medicine have opened promising avenues to apply neuroprotective therapy, gene therapy, cell replacement therapy, and visual prostheses to the challenge of restoring vision. However, successful visual restoration in the clinical setting requires application of these therapeutic approaches at the appropriate stage of the retinal degeneration. In this review, firstly, we discuss the mechanisms of PR degeneration by focusing on the molecular mechanisms underlying cell death. Subsequently, innovations, recent developments, and promising treatments based on the stage of disorder progression are further explored. Then, the challenges to be addressed before implementation of these therapies in clinical practice are considered. Finally, potential solutions to overcome the current limitations of this growing research area are suggested. Overall, the majority of current treatment modalities are still at an early stage of development and require extensive additional studies, both pre-clinical and clinical, before full restoration of visual function in PR degeneration diseases can be realized.
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Affiliation(s)
- Fereshteh Karamali
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sanaz Behtaj
- grid.1022.10000 0004 0437 5432Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia ,grid.1022.10000 0004 0437 5432Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia
| | - Shahnaz Babaei-Abraki
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hanieh Hadady
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Atefeh Atefi
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Soraya Savoj
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Samaneh Najafian
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr Esfahani
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Henry Klassen
- grid.266093.80000 0001 0668 7243Gavin Herbert Eye Institute, Irvine, CA USA
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5
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Picarazzi F, Zuanon M, Pasqualetto G, Cammarone S, Romeo I, Young MT, Brancale A, Bassetto M, Mori M. Identification of Small Molecular Chaperones Binding P23H Mutant Opsin through an In Silico Structure-Based Approach. J Chem Inf Model 2022; 62:5794-5805. [PMID: 36367985 DOI: 10.1021/acs.jcim.2c01040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
N-terminal P23H opsin mutation accounts for most of retinitis pigmentosa (RP) cases. P23H functions and folding can be rescued by small chaperone ligands, which contributes to validate mutant opsin as a suitable target for pharmacological treatment of RP. However, the lack of structural details on P23H mutant opsin strongly impairs drug design, and new chemotypes of effective chaperones of P23H opsin are in high demand. Here, a computational-boosted workflow combining homology modeling with molecular dynamics (MD) simulations and virtual screening was used to select putative P23H opsin chaperones among different libraries through a structure-based approach. In vitro studies corroborated the reliability of the structural model generated in this work and identified a number of novel chemotypes of safe and effective chaperones able to promote P23H opsin trafficking to the outer cell membrane.
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Affiliation(s)
- Francesca Picarazzi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Marika Zuanon
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Gaia Pasqualetto
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
| | - Silvia Cammarone
- Dipartimento di Chimica e Tecnologie del Farmaco, Facoltà di Farmacia e Medicina, "Sapienza" Università di Roma, P. le Aldo Moro 5, 00185 Roma, Italy
| | - Isabella Romeo
- Dipartimento di Chimica e Tecnologie del Farmaco, Facoltà di Farmacia e Medicina, "Sapienza" Università di Roma, P. le Aldo Moro 5, 00185 Roma, Italy
| | - Mark T Young
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK.,Vysoká Škola Chemicko-Technologiká v Praze, Prague 166 28, Czech Republic
| | - Marcella Bassetto
- Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea SA2 8PP, UK
| | - Mattia Mori
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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6
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Ichsan AM, Bukhari A, Lallo S, Miskad UA, Dzuhry AA, Islam IC, Muhiddin HS. Effect of retinol and α-tocopherol supplementation on photoreceptor and retinal ganglion cell apoptosis in diabetic rats model. Int J Retina Vitreous 2022; 8:40. [PMID: 35715832 PMCID: PMC9205037 DOI: 10.1186/s40942-022-00392-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/01/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is the most common microvascular complication of diabetes. Retinol and α-tocopherol of diabetic models prevent the damage of photoreceptor and retinal ganglion cells (RGC) caused by hyperglycemia. OBJECTIVE This study aims to examine the effect of retinol and α-tocopherol on photoreceptor and RGC densities and the expression of caspase-3 and -7 on the retinal layers of the diabetic rat model. METHODS Alloxan 150 mg/kg body weight single dose was used to develop animal models, which were separated into eight groups. These consist of one group without intervention (group 1), one positive control with only induced alloxan (group 2), and others receiving retinol (group 3 and 6), α-tocopherol (group 4 and 7), or their combination (group 5 and 8). Furthermore, histopathological examination was performed using Hematoxylin-Eosin staining to evaluate the photoreceptor and RGC densities, while immunohistochemistry staining evaluated the caspase-3 and -7 expressions. RESULTS In the treatment group, the highest and lowest densities were identified in diabetic rats given α-tocopherol (group 7) and retinol (group 3) respectively. The caspase-3 and -7 expression showed that the group given α-tocopherol (group 7) had the lowest value. CONCLUSION In diabetic rats, retinol and α-tocopherol compounds maintained densities and prevented photoreceptor and RGC death. However, α-tocopherol was more promising than retinol or combinations in the prevention of retinal cells apoptosis.
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Affiliation(s)
- Andi Muhammad Ichsan
- Department of Ophthalmology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia.
| | - Agussalim Bukhari
- Department of Clinical Nutrition, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Subehan Lallo
- Department of Pharmaceutical Science, Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia
| | - Upik Anderiani Miskad
- Department of Pathology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Andi Afdal Dzuhry
- Department of Ophthalmology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Itzar Chaidir Islam
- Department of Ophthalmology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
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7
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Trifonov L, Rothstein A, Korshin EE, Viskind O, Afri M, Leitus G, Palczewski K, Gruzman A. Straightforward Access to Terminally Disubstituted Electron‐Deficient Alkylidene Cyclopent‐2‐en‐4‐ones through Olefination with α‐Carbonyl and α‐Cyano Secondary Alkyl Sulfones. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lena Trifonov
- Department of Chemistry, Bar-Ilan University Max and Anna Webb St. Ramat-Gan 5290002 Israel
| | - Ayelet Rothstein
- Department of Chemistry, Bar-Ilan University Max and Anna Webb St. Ramat-Gan 5290002 Israel
| | - Edward E. Korshin
- Department of Chemistry, Bar-Ilan University Max and Anna Webb St. Ramat-Gan 5290002 Israel
| | - Olga Viskind
- Department of Chemistry, Bar-Ilan University Max and Anna Webb St. Ramat-Gan 5290002 Israel
| | - Michal Afri
- Department of Chemistry, Bar-Ilan University Max and Anna Webb St. Ramat-Gan 5290002 Israel
| | - Gregory Leitus
- Department of Chemical Research Support the Weizmann Institute of Science Rehovot 76100 Israel
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute Department of Ophthalmology and Departments of Physiology and Biophysics and Chemistry and Molecular Biology and Biochemistry, University of California Irvine CA 92697 USA
| | - Arie Gruzman
- Department of Chemistry, Bar-Ilan University Max and Anna Webb St. Ramat-Gan 5290002 Israel
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8
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Pasqualetto G, Pileggi E, Schepelmann M, Varricchio C, Rozanowska M, Brancale A, Bassetto M. Ligand-based rational design, synthesis and evaluation of novel potential chemical chaperones for opsin. Eur J Med Chem 2021; 226:113841. [PMID: 34555613 DOI: 10.1016/j.ejmech.2021.113841] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/07/2021] [Accepted: 09/07/2021] [Indexed: 12/01/2022]
Abstract
Inherited blinding diseases retinitis pigmentosa (RP) and a subset of Leber's congenital amaurosis (LCA) are caused by the misfolding and mistrafficking of rhodopsin molecules, which aggregate and accumulate in the endoplasmic reticulum (ER), leading to photoreceptor cell death. One potential therapeutic strategy to prevent the loss of photoreceptors in these conditions is to identify opsin-binding compounds that act as chemical chaperones for opsin, aiding its proper folding and trafficking to the outer cell membrane. Aiming to identify novel compounds with such effect, a rational ligand-based approach was applied to the structure of the visual pigment chromophore, 11-cis-retinal, and its locked analogue 11-cis-6mr-retinal. Following molecular docking studies on the main chromophore binding site of rhodopsin, 49 novel compounds were synthesized according to optimized one-to seven-step synthetic routes. These agents were evaluated for their ability to compete for the chromophore binding site of opsin, and their capacity to increase the trafficking of the P23H opsin mutant from the ER to the cell membrane. Different new molecules displayed an effect in at least one assay, acting either as chemical chaperones or as stabilizers of the 9-cis-retinal-rhodopsin complex. These compounds could provide the basis to develop novel therapeutics for RP and LCA.
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Affiliation(s)
- Gaia Pasqualetto
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK
| | - Elisa Pileggi
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK
| | - Martin Schepelmann
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, 1090, Austria; School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Carmine Varricchio
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK
| | - Malgorzata Rozanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK; Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff, CF10 3NB, UK
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK
| | - Marcella Bassetto
- Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea, SA2 8PP, UK.
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9
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Felline A, Schiroli D, Comitato A, Marigo V, Fanelli F. Structure network-based landscape of rhodopsin misfolding by mutations and algorithmic prediction of small chaperone action. Comput Struct Biotechnol J 2021; 19:6020-6038. [PMID: 34849206 PMCID: PMC8605067 DOI: 10.1016/j.csbj.2021.10.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/09/2021] [Accepted: 10/31/2021] [Indexed: 11/28/2022] Open
Abstract
Failure of a protein to achieve its functional structural state and normal cellular location contributes to the etiology and pathology of heritable human conformational diseases. The autosomal dominant form of retinitis pigmentosa (adRP) is an incurable blindness largely linked to mutations of the membrane protein rod opsin. While the mechanisms underlying the noxious effects of the mutated protein are not completely understood, a common feature is the functional protein conformational loss. Here, the wild type and 39 adRP rod opsin mutants were subjected to mechanical unfolding simulations coupled to the graph theory-based protein structure network analysis. A robust computational model was inferred and in vitro validated in its ability to predict endoplasmic reticulum retention of adRP mutants, a feature linked to the mutation-caused misfolding. The structure-based approach could also infer the structural determinants of small chaperone action on misfolded protein mutants with therapeutic implications. The approach is exportable to conformational diseases linked to missense mutations in any membrane protein.
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Affiliation(s)
- Angelo Felline
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy
| | - Davide Schiroli
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Antonella Comitato
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy.,Center for Neuroscience and Neurotechnology, Italy
| | - Francesca Fanelli
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy.,Center for Neuroscience and Neurotechnology, Italy
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10
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Sethna S, Zein WM, Riaz S, Giese AP, Schultz JM, Duncan T, Hufnagel RB, Brewer CC, Griffith AJ, Redmond TM, Riazuddin S, Friedman TB, Ahmed ZM. Proposed therapy, developed in a Pcdh15-deficient mouse, for progressive loss of vision in human Usher syndrome. eLife 2021; 10:67361. [PMID: 34751129 PMCID: PMC8577840 DOI: 10.7554/elife.67361] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 10/20/2021] [Indexed: 12/15/2022] Open
Abstract
Usher syndrome type I (USH1) is characterized by deafness, vestibular areflexia, and progressive retinal degeneration. The protein-truncating p.Arg245* founder variant of PCDH15 (USH1F) has an ~2% carrier frequency amongst Ashkenazi Jews accounts for ~60% of their USH1 cases. Here, longitudinal phenotyping in 13 USH1F individuals revealed progressive retinal degeneration, leading to severe vision loss with macular atrophy by the sixth decade. Half of the affected individuals were legally blind by their mid-50s. The mouse Pcdh15R250X variant is equivalent to human p.Arg245*. Homozygous Pcdh15R250X mice also have visual deficits and aberrant light-dependent translocation of the phototransduction cascade proteins, arrestin, and transducin. Retinal pigment epithelium (RPE)-specific retinoid cycle proteins, RPE65 and CRALBP, were also reduced in Pcdh15R250X mice, indicating a dual role for protocadherin-15 in photoreceptors and RPE. Exogenous 9-cis retinal improved ERG amplitudes in Pcdh15R250X mice, suggesting a basis for a clinical trial of FDA-approved retinoids to preserve vision in USH1F patients.
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Affiliation(s)
- Saumil Sethna
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Sehar Riaz
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States.,National Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Arnaud Pj Giese
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States
| | - Julie M Schultz
- Laboratory of Molecular Genetics, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, United States
| | - Todd Duncan
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Carmen C Brewer
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, Bethesda, United States
| | - Andrew J Griffith
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, Bethesda, United States
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Saima Riazuddin
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, United States
| | - Zubair M Ahmed
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States.,Departments of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, United States.,Departments of Molecular Biology and Biochemistry, University of Maryland School of Medicine, Baltimore, United States
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11
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Haghighat M, Iranbakhsh A, Baharara J, Ebadi M, Sotoodehnejadnematalahia F. Evaluation of the Potential Effects of Retinol and Alginate/Gelatin-Based Scaffolds on Differentiation Capacity of Mouse Mesenchymal Stem Cells (MSCs) into Retinal Cells. Int J Stem Cells 2021; 15:183-194. [PMID: 34711698 PMCID: PMC9148832 DOI: 10.15283/ijsc21062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 11/09/2022] Open
Abstract
Background and Objectives Retinal stem cells (RSCs) resided in ciliary epithelium have shown to possess a high capacity to self-renew and differentiate into retinal cells. RSCs could be induced to differentiate when they are exposed to stimuli like natural compounds and suitable contexts such as biomaterials. The aim of this study was to examine the effects of Retinol and alginate/gelatin-based scaffolds on differentiation potential of mesenchymal stem cells (MSCs) originated from mouse ciliary epithelium. Methods and Results MSCs were extracted from mouse ciliary epithelium, and their identity was verified by detecting specific surface antigens. To provide a three-dimensional in vitro culture system, 2% alginate, 0.5% gelatin and the mixed alginate-gelatin hydrogels were fabricated and checked by SEM. Retinol treatment was performed on MSCs expanded on alginate/gelatin hydrogels and the survival rate and the ability of MSCs to differentiate were examined through measuring expression alterations of retina-specific genes by ICC and qPCR. The cell population isolated from ciliary epithelium contained more than 93.4% cells positive for MSC-specific marker CD105. Alginate/gelatin scaffolds showed to provide an acceptable viability (over 70%) for MSC cultures. Retinol treatment could induce a high expression of rhodopsin protein in MSCs expanded in alginate and alginate-gelatin mixtures. An elevated presentation of Nestin, RPE65 and Rhodopsin genes was detected in retinol-treated cultures expanded on alginate and alginate-gelatin scaffolds. Conclusions The results presented here elucidate that retinol treatment of MSCs grown on alginate scaffolds would promote the mouse ciliary epithelium-derived MSCs to differentiate towards retinal neurons.
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Affiliation(s)
- Mahtab Haghighat
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Alireza Iranbakhsh
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Javad Baharara
- Department of Biology, Applied Biology Research Center, Mashhad Branch, Islamic Azad University, Mashhad, Iran
| | - Mostafa Ebadi
- Department of Biology, Damghan Branch, Islamic Azad University, Damghan, Iran
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12
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Tomita Y, Usui-Ouchi A, Nilsson AK, Yang J, Ko M, Hellström A, Fu Z. Metabolism in Retinopathy of Prematurity. Life (Basel) 2021; 11:1119. [PMID: 34832995 PMCID: PMC8620873 DOI: 10.3390/life11111119] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/11/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
Retinopathy of prematurity is defined as retinal abnormalities that occur during development as a consequence of disturbed oxygen conditions and nutrient supply after preterm birth. Both neuronal maturation and retinal vascularization are impaired, leading to the compensatory but uncontrolled retinal neovessel growth. Current therapeutic interventions target the hypoxia-induced neovessels but negatively impact retinal neurons and normal vessels. Emerging evidence suggests that metabolic disturbance is a significant and underexplored risk factor in the disease pathogenesis. Hyperglycemia and dyslipidemia correlate with the retinal neurovascular dysfunction in infants born prematurely. Nutritional and hormonal supplementation relieve metabolic stress and improve retinal maturation. Here we focus on the mechanisms through which metabolism is involved in preterm-birth-related retinal disorder from clinical and experimental investigations. We will review and discuss potential therapeutic targets through the restoration of metabolic responses to prevent disease development and progression.
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Affiliation(s)
- Yohei Tomita
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
| | - Ayumi Usui-Ouchi
- Department of Ophthalmology, Juntendo University Urayasu Hospital, Chiba 279-0021, Japan;
| | - Anders K. Nilsson
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 413 19 Gothenburg, Sweden; (A.K.N.); (A.H.)
| | - Jay Yang
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
| | - Minji Ko
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
| | - Ann Hellström
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 413 19 Gothenburg, Sweden; (A.K.N.); (A.H.)
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
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13
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Technological advancements to study cellular signaling pathways in inherited retinal degenerative diseases. Curr Opin Pharmacol 2021; 60:102-110. [PMID: 34388439 DOI: 10.1016/j.coph.2021.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/02/2021] [Indexed: 01/01/2023]
Abstract
Inherited retinal degenerative diseases (IRDs) are rare neurodegenerative disorders with mutations in hundreds of genes leading to vision loss, primarily owing to photoreceptor cell death. This genetic diversity is impeding development of effective treatment options. Gene-based therapies have resulted in the first FDA-approved drug (Luxturna) for RPE65-specific IRD. Although currently explored in clinical trials, genomic medicines are mutation-dependent, hence suitable only for patients harboring a specific mutation. Better understanding of the pathways leading to photoreceptor degeneration may help to determine common targets and develop mutation-independent therapies for larger groups of patients with IRDs. In this review, we discuss the key pathways involved in photoreceptor cell death studied by transcriptomics, proteomics, and metabolomics techniques to identify potential therapeutic targets in IRDs.
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14
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Sethna S, Scott PA, Giese APJ, Duncan T, Jian X, Riazuddin S, Randazzo PA, Redmond TM, Bernstein SL, Riazuddin S, Ahmed ZM. CIB2 regulates mTORC1 signaling and is essential for autophagy and visual function. Nat Commun 2021; 12:3906. [PMID: 34162842 PMCID: PMC8222345 DOI: 10.1038/s41467-021-24056-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 05/26/2021] [Indexed: 02/06/2023] Open
Abstract
Age-related macular degeneration (AMD) is a multifactorial neurodegenerative disorder. Although molecular mechanisms remain elusive, deficits in autophagy have been associated with AMD. Here we show that deficiency of calcium and integrin binding protein 2 (CIB2) in mice, leads to age-related pathologies, including sub-retinal pigment epithelium (RPE) deposits, marked accumulation of drusen markers APOE, C3, Aβ, and esterified cholesterol, and impaired visual function, which can be rescued using exogenous retinoids. Cib2 mutant mice exhibit reduced lysosomal capacity and autophagic clearance, and increased mTORC1 signaling-a negative regulator of autophagy. We observe concordant molecular deficits in dry-AMD RPE/choroid post-mortem human tissues. Mechanistically, CIB2 negatively regulates mTORC1 by preferentially binding to 'nucleotide empty' or inactive GDP-loaded Rheb. Upregulated mTORC1 signaling has been implicated in lymphangioleiomyomatosis (LAM) cancer. Over-expressing CIB2 in LAM patient-derived fibroblasts downregulates hyperactive mTORC1 signaling. Thus, our findings have significant implications for treatment of AMD and other mTORC1 hyperactivity-associated disorders.
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Affiliation(s)
- Saumil Sethna
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Patrick A Scott
- Department of Ophthalmology & Visual Sciences, University of Louisville, Louisville, KY, USA
| | - Arnaud P J Giese
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Todd Duncan
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Xiaoying Jian
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sheikh Riazuddin
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - Paul A Randazzo
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Steven L Bernstein
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Saima Riazuddin
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Zubair M Ahmed
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA.
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.
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15
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Chiu W, Lin TY, Chang YC, Isahwan-Ahmad Mulyadi Lai H, Lin SC, Ma C, Yarmishyn AA, Lin SC, Chang KJ, Chou YB, Hsu CC, Lin TC, Chen SJ, Chien Y, Yang YP, Hwang DK. An Update on Gene Therapy for Inherited Retinal Dystrophy: Experience in Leber Congenital Amaurosis Clinical Trials. Int J Mol Sci 2021; 22:ijms22094534. [PMID: 33926102 PMCID: PMC8123696 DOI: 10.3390/ijms22094534] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/22/2021] [Accepted: 04/22/2021] [Indexed: 12/20/2022] Open
Abstract
Inherited retinal dystrophies (IRDs) are a group of rare eye diseases caused by gene mutations that result in the degradation of cone and rod photoreceptors or the retinal pigment epithelium. Retinal degradation progress is often irreversible, with clinical manifestations including color or night blindness, peripheral visual defects and subsequent vision loss. Thus, gene therapies that restore functional retinal proteins by either replenishing unmutated genes or truncating mutated genes are needed. Coincidentally, the eye’s accessibility and immune-privileged status along with major advances in gene identification and gene delivery systems heralded gene therapies for IRDs. Among these clinical trials, voretigene neparvovec-rzyl (Luxturna), an adeno-associated virus vector-based gene therapy drug, was approved by the FDA for treating patients with confirmed biallelic RPE65 mutation-associated Leber Congenital Amaurosis (LCA) in 2017. This review includes current IRD gene therapy clinical trials and further summarizes preclinical studies and therapeutic strategies for LCA, including adeno-associated virus-based gene augmentation therapy, 11-cis-retinal replacement, RNA-based antisense oligonucleotide therapy and CRISPR-Cas9 gene-editing therapy. Understanding the gene therapy development for LCA may accelerate and predict the potential hurdles of future therapeutics translation. It may also serve as the template for the research and development of treatment for other IRDs.
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Affiliation(s)
- Wei Chiu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan; (W.C.); (S.-C.L.); (S.-C.L.); (K.-J.C.); (Y.-B.C.); (C.-C.H.)
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
| | - Ting-Yi Lin
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- School of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Yun-Chia Chang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Henkie Isahwan-Ahmad Mulyadi Lai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
| | - Shen-Che Lin
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan; (W.C.); (S.-C.L.); (S.-C.L.); (K.-J.C.); (Y.-B.C.); (C.-C.H.)
| | - Chun Ma
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Department of Medicine, National Taiwan University, Taipei 10617, Taiwan
| | - Aliaksandr A. Yarmishyn
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
| | - Shiuan-Chen Lin
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan; (W.C.); (S.-C.L.); (S.-C.L.); (K.-J.C.); (Y.-B.C.); (C.-C.H.)
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
| | - Kao-Jung Chang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan; (W.C.); (S.-C.L.); (S.-C.L.); (K.-J.C.); (Y.-B.C.); (C.-C.H.)
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
| | - Yu-Bai Chou
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan; (W.C.); (S.-C.L.); (S.-C.L.); (K.-J.C.); (Y.-B.C.); (C.-C.H.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Chih-Chien Hsu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan; (W.C.); (S.-C.L.); (S.-C.L.); (K.-J.C.); (Y.-B.C.); (C.-C.H.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Tai-Chi Lin
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Shih-Jen Chen
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Yueh Chien
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Division of Basic Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Correspondence: (Y.C.); (Y.-P.Y.); (D.-K.H.)
| | - Yi-Ping Yang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Division of Basic Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Institute of Food Safety and Health Risk Assessment, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
- Correspondence: (Y.C.); (Y.-P.Y.); (D.-K.H.)
| | - De-Kuang Hwang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (T.-Y.L.); (H.I.-A.M.L.); (C.M.); (A.A.Y.); (T.-C.L.); (S.-J.C.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
- Correspondence: (Y.C.); (Y.-P.Y.); (D.-K.H.)
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16
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Fu Z, Qiu C, Cagnone G, Tomita Y, Huang S, Cakir B, Kotoda Y, Allen W, Bull E, Akula JD, Joyal JS, Hellström A, Talukdar S, Smith LEH. Retinal glial remodeling by FGF21 preserves retinal function during photoreceptor degeneration. iScience 2021; 24:102376. [PMID: 33937726 PMCID: PMC8079476 DOI: 10.1016/j.isci.2021.102376] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/13/2021] [Accepted: 03/25/2021] [Indexed: 12/18/2022] Open
Abstract
The group of retinal degenerations, retinitis pigmentosa (RP), comprises more than 150 genetic abnormalities affecting photoreceptors. Finding degenerative pathways common to all genetic abnormalities may allow general treatment such as neuroprotection. Neuroprotection may include enhancing the function of cells that directly support photoreceptors, retinal pigment epithelial cells, and Müller glia. Treatment with fibroblast growth factor 21 (FGF21), a neuroprotectant, from postnatal week 4-10, during rod and cone loss in P23H mice (an RP model) with retinal degeneration, preserved photoreceptor function and normalized Müller glial cell morphology. Single-cell transcriptomics of retinal cells showed that FGF21 receptor Fgfr1 was specifically expressed in Müller glia/astrocytes. Of all retinal cells, FGF21 predominantly affected genes in Müller glia/astrocytes with increased expression of axon development and synapse formation pathway genes. Therefore, enhancing retinal glial axon and synapse formation with neurons may preserve retinal function in RP and may suggest a general therapeutic approach for retinal degenerative diseases.
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Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.,The Manton Center for Orphan Disease, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Chenxi Qiu
- Department of Medicine, Division of Translational Therapeutics, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Gael Cagnone
- Department of Pediatrics, Pharmacology and Ophthalmology, CHU Sainte-Justine Research Center, Université de Montréal, Montreal, Qc H3A 0C4, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, Qc H3A 0C4, Canada
| | - Yohei Tomita
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Shuo Huang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Bertan Cakir
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Yumi Kotoda
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - William Allen
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Edward Bull
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - James D Akula
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jean-Sébastien Joyal
- Department of Pediatrics, Pharmacology and Ophthalmology, CHU Sainte-Justine Research Center, Université de Montréal, Montreal, Qc H3A 0C4, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, Qc H3A 0C4, Canada
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg 405 30, Sweden
| | - Saswata Talukdar
- Cardiometabolic Diseases, Merck Research Laboratories, 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
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17
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Fanelli F, Felline A, Marigo V. Structural aspects of rod opsin and their implication in genetic diseases. Pflugers Arch 2021; 473:1339-1359. [PMID: 33728518 DOI: 10.1007/s00424-021-02546-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 02/17/2021] [Accepted: 02/22/2021] [Indexed: 01/04/2023]
Abstract
Vision in dim-light conditions is triggered by photoactivation of rhodopsin, the visual pigment of rod photoreceptor cells. Rhodopsin is made of a protein, the G protein coupled receptor (GPCR) opsin, and the chromophore 11-cis-retinal. Vertebrate rod opsin is the GPCR best characterized at the atomic level of detail. Since the release of the first crystal structure 20 years ago, a huge number of structures have been released that, in combination with valuable spectroscopic determinations, unveiled most aspects of the photobleaching process. A number of spontaneous mutations of rod opsin have been found linked to vision-impairing diseases like autosomal dominant or autosomal recessive retinitis pigmentosa (adRP or arRP, respectively) and autosomal congenital stationary night blindness (adCSNB). While adCSNB is mainly caused by constitutive activation of rod opsin, RP shows more variegate determinants affecting different aspects of rod opsin function. The vast majority of missense rod opsin mutations affects folding and trafficking and is linked to adRP, an incurable disease that awaits light on its molecular structure determinants. This review article summarizes all major structural information available on vertebrate rod opsin conformational states and the insights gained so far into the structural determinants of adCSNB and adRP linked to rod opsin mutations. Strategies to design small chaperones with therapeutic potential for selected adRP rod opsin mutants will be discussed as well.
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Affiliation(s)
- Francesca Fanelli
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125, Modena, Italy. .,Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via Campi 287, Modena, 41125, Italy.
| | - Angelo Felline
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125, Modena, Italy
| | - Valeria Marigo
- Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via Campi 287, Modena, 41125, Italy.,Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125, Modena, Italy
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18
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Yu G, Gao SQ, Dong Z, Sheng L, Sun D, Zhang N, Zhang J, Margeivicus S, Fu P, Golczak M, Maeda A, Palczewski K, Lu ZR. Peptide Derivatives of Retinylamine Prevent Retinal Degeneration with Minimal Side Effects on Vision in Mice. Bioconjug Chem 2021; 32:572-583. [PMID: 33677964 DOI: 10.1021/acs.bioconjchem.1c00043] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Safe and effective molecular therapeutics for prophylactic treatment of retinal degenerative diseases are greatly needed. Disruptions in the clearance of all-trans-retinal (atRAL) by the visual (retinoid) cycle of the retina can lead to the accumulation of atRAL and its condensation products known to initiate progressive retinal dystrophy. Retinylamine (Ret-NH2) and its analogues are known to be effective in lowering the concentration of atRAL within the eye and thus preventing retinal degeneration in mouse models of human retinopathies. Here, we chemically modified Ret-NH2 with amino acids and peptides to improve the stability and ocular bioavailability of the resulting derivatives and to minimize their side effects. Fourteen Ret-NH2 derivatives were synthesized and tested in vitro and in vivo. These derivatives exhibited structure-dependent therapeutic efficacy in preventing light-induced retinal degeneration in Abca4-/-Rdh8-/- double-knockout mice, with the compounds containing glycine and/or L-valine generally exhibiting greater protective effects than Ret-NH2 or other tested amino acid derivatives of Ret-NH2. Ret-NH2-L-valylglycine amide (RVG) exhibited good stability in storage; and effective uptake and prolonged retention in mouse eyes. RVG readily formed a Schiff base with atRAL and did not inhibit RPE65 enzymatic activity. Administered by oral gavage, this retinoid also provided effective protection against light-induced retinal degeneration in Abca4-/-Rdh8-/- mice. Notably, the treatment with RVG had minimal effects on the regeneration of 11-cis-retinal and recovery of retinal function. RVG holds promise as a lead therapy for effective and safe treatment of human retinal degenerative diseases.
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Affiliation(s)
- Guanping Yu
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Song-Qi Gao
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Zhiqian Dong
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States
| | - Li Sheng
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Da Sun
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Ning Zhang
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Jianye Zhang
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States
| | - Seunghee Margeivicus
- Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Pingfu Fu
- Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Marcin Golczak
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Akiko Maeda
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States.,Department of Ophthalmology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Krzysztof Palczewski
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States
| | - Zheng-Rong Lu
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
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19
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Fu Z, Kern TS, Hellström A, Smith LEH. Fatty acid oxidation and photoreceptor metabolic needs. J Lipid Res 2021; 62:100035. [PMID: 32094231 PMCID: PMC7905050 DOI: 10.1194/jlr.tr120000618] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/14/2020] [Indexed: 01/31/2023] Open
Abstract
Photoreceptors have high energy demands and a high density of mitochondria that produce ATP through oxidative phosphorylation (OXPHOS) of fuel substrates. Although glucose is the major fuel for CNS brain neurons, in photoreceptors (also CNS), most glucose is not metabolized through OXPHOS but is instead metabolized into lactate by aerobic glycolysis. The major fuel sources for photoreceptor mitochondria remained unclear for almost six decades. Similar to other tissues (like heart and skeletal muscle) with high metabolic rates, photoreceptors were recently found to metabolize fatty acids (palmitate) through OXPHOS. Disruption of lipid entry into photoreceptors leads to extracellular lipid accumulation, suppressed glucose transporter expression, and a duel lipid/glucose fuel shortage. Modulation of lipid metabolism helps restore photoreceptor function. However, further elucidation of the types of lipids used as retinal energy sources, the metabolic interaction with other fuel pathways, as well as the cross-talk among retinal cells to provide energy to photoreceptors is not fully understood. In this review, we will focus on the current understanding of photoreceptor energy demand and sources, and potential future investigations of photoreceptor metabolism.
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Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Manton Center for Orphan Disease, Boston Children's Hospital, Boston, MA, USA.
| | - Timothy S Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Irvine, CA, USA
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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20
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Kiser PD, Palczewski K. Pathways and disease-causing alterations in visual chromophore production for vertebrate vision. J Biol Chem 2021; 296:100072. [PMID: 33187985 PMCID: PMC7948990 DOI: 10.1074/jbc.rev120.014405] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022] Open
Abstract
All that we view of the world begins with an ultrafast cis to trans photoisomerization of the retinylidene chromophore associated with the visual pigments of rod and cone photoreceptors. The continual responsiveness of these photoreceptors is then sustained by regeneration processes that convert the trans-retinoid back to an 11-cis configuration. Recent biochemical and electrophysiological analyses of the retinal G-protein-coupled receptor (RGR) suggest that it could sustain the responsiveness of photoreceptor cells, particularly cones, even under bright light conditions. Thus, two mechanisms have evolved to accomplish the reisomerization: one involving the well-studied retinoid isomerase (RPE65) and a second photoisomerase reaction mediated by the RGR. Impairments to the pathways that transform all-trans-retinal back to 11-cis-retinal are associated with mild to severe forms of retinal dystrophy. Moreover, with age there also is a decline in the rate of chromophore regeneration. Both pharmacological and genetic approaches are being used to bypass visual cycle defects and consequently mitigate blinding diseases. Rapid progress in the use of genome editing also is paving the way for the treatment of disparate retinal diseases. In this review, we provide an update on visual cycle biochemistry and then discuss visual-cycle-related diseases and emerging therapeutics for these disorders. There is hope that these advances will be helpful in treating more complex diseases of the eye, including age-related macular degeneration (AMD).
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Affiliation(s)
- Philip D Kiser
- The Department of Physiology & Biophysics, University of California, Irvine, California, USA; Research Service, The VA Long Beach Health Care System, Long Beach, California, USA; The Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California, USA.
| | - Krzysztof Palczewski
- The Department of Physiology & Biophysics, University of California, Irvine, California, USA; The Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California, USA; The Department of Chemistry, University of California, Irvine, California, USA.
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21
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Ortega JT, Parmar T, Golczak M, Jastrzebska B. Protective Effects of Flavonoids in Acute Models of Light-Induced Retinal Degeneration. Mol Pharmacol 2020; 99:60-77. [PMID: 33154094 DOI: 10.1124/molpharm.120.000072] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/26/2020] [Indexed: 12/17/2022] Open
Abstract
Degeneration of photoreceptors caused by excessive illumination, inherited mutations, or aging is the principal pathology of blinding diseases. Pharmacological compounds that stabilize the visual receptor rhodopsin and modulate the cellular pathways triggering death of photoreceptors could avert this pathology. Interestingly, flavonoids can modulate the cellular processes, such as oxidative stress, inflammatory responses, and apoptosis, that are activated during retinal degeneration. As we found previously, flavonoids also bind directly to unliganded rod opsin, enhancing its folding, stability, and regeneration. In addition, flavonoids stimulate rhodopsin gene expression. Thus, we evaluated the effect of two main dietary flavonoids, quercetin and myricetin, in ATP-binding cassette subfamily A member 4 -/- /retinol dehydrogenase 8 -/- and wild-type BALB/c mice susceptible to light-induced photoreceptor degeneration. Using in vivo imaging, such as optical coherence tomography, scanning laser ophthalmoscopy, and histologic assessment of retinal morphology, we found that treatment with these flavonoids prior to light insult remarkably protected retina from deterioration and preserved its function. Using high-performance liquid chromatography-mass spectrometry analysis, we detected these flavonoids in the eye upon their intraperitoneal administration. The molecular events associated with the protective effect of quercetin and myricetin were related to the elevated expression of photoreceptor-specific proteins, rhodopsin and cone opsins, decreased expression of the specific inflammatory markers, and the shift of the equilibrium between cell death regulators BCL2-associated X protein (BAX) and B-cell lymphoma 2 toward an antiapoptotic profile. These results were confirmed in photoreceptor-derived 661W cells treated with either H2O2 or all-trans-retinal stressors implicated in the mechanism of retinal degeneration. Altogether, flavonoids could have significant prophylactic value for retinal degenerative diseases. SIGNIFICANCE STATEMENT: Flavonoids commonly present in food exhibit advantageous effects in blinding diseases. They bind to and stabilize unliganded rod opsin, which in excess accelerates degenerative processes in the retina. Additionally, flavonoids enhance the expression of the visual receptors, rod and cone opsins; inhibit the inflammatory reactions; and induce the expression of antiapoptotic markers in the retina, preventing the degeneration in vivo. Thus, flavonoids could have a prophylactic value for retinal degenerative diseases.
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Affiliation(s)
- Joseph T Ortega
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Tanu Parmar
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Marcin Golczak
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Beata Jastrzebska
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
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22
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Parmar T, Ortega JT, Jastrzebska B. Retinoid analogs and polyphenols as potential therapeutics for age-related macular degeneration. Exp Biol Med (Maywood) 2020; 245:1615-1625. [PMID: 32438835 PMCID: PMC7787542 DOI: 10.1177/1535370220926938] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
IMPACT STATEMENT Age-related macular degeneration (AMD) is a devastating retinal degenerative disease. Epidemiological reports showed an expected increasing prevalence of AMD in the near future. The only one existing FDA-approved pharmacological treatment involves an anti-vascular endothelial growth factor (VEGF) therapy with serious disadvantages. This limitation emphasizes an alarming need to develop new therapeutic approaches to prevent and treat AMD. In this review, we summarize scientific data unraveling the therapeutic potential of the specific retinoid and natural compounds. The experimental results reported by us and other research groups demonstrated that retinoid analogs and compounds with natural product scaffolds could serve as lead compounds for the development of new therapeutic agents with potential to prevent or slow down the pathogenesis of AMD.
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Affiliation(s)
- Tanu Parmar
- Department of Pharmacology, and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Joseph T Ortega
- Department of Pharmacology, and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Beata Jastrzebska
- Department of Pharmacology, and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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23
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von Lintig J, Moon J, Lee J, Ramkumar S. Carotenoid metabolism at the intestinal barrier. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158580. [PMID: 31794861 PMCID: PMC7987234 DOI: 10.1016/j.bbalip.2019.158580] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 12/17/2022]
Abstract
Carotenoids exert a rich variety of physiological functions in mammals and are beneficial for human health. These lipids are acquired from the diet and metabolized to apocarotenoids, including retinoids (vitamin A and its metabolites). The small intestine is a major site for their absorption and bioconversion. From here, carotenoids and their metabolites are distributed within the body in triacylglycerol-rich lipoproteins to support retinoid signaling in peripheral tissues and photoreceptor function in the eyes. In recent years, much progress has been made in identifying carotenoid metabolizing enzymes, transporters, and binding proteins. A diet-responsive regulatory network controls the activity of these components and adapts carotenoid absorption and bioconversion to the bodily requirements of these lipids. Genetic variability in the genes encoding these components alters carotenoid homeostasis and is associated with pathologies. We here summarize the advanced state of knowledge about intestinal carotenoid metabolism and its impact on carotenoid and retinoid homeostasis of other organ systems, including the eyes, liver, and immune system. The implication of the findings for science-based intake recommendations for these essential dietary lipids is discussed. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.
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Affiliation(s)
- Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States of America.
| | - Jean Moon
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States of America
| | - Joan Lee
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States of America
| | - Srinivasagan Ramkumar
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States of America
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24
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Pasqualetto G, Schepelmann M, Varricchio C, Pileggi E, Khogali C, Morgan SR, Boostrom I, Rozanowska M, Brancale A, Ferla S, Bassetto M. Computational Studies towards the Identification of Novel Rhodopsin-Binding Compounds as Chemical Chaperones for Misfolded Opsins. Molecules 2020; 25:molecules25214904. [PMID: 33114011 PMCID: PMC7660337 DOI: 10.3390/molecules25214904] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 01/19/2023] Open
Abstract
Accumulation of misfolded and mistrafficked rhodopsin on the endoplasmic reticulum of photoreceptor cells has a pivotal role in the pathogenesis of retinitis pigmentosa and a subset of Leber’s congenital amaurosis. One potential strategy to reduce rhodopsin misfolding and aggregation in these conditions is to use opsin-binding compounds as chemical chaperones for opsin. Such molecules have previously shown the ability to aid rhodopsin folding and proper trafficking to the outer cell membranes of photoreceptors. As means to identify novel chemical chaperones for rhodopsin, a structure-based virtual screening of commercially available drug-like compounds (300,000) was performed on the main binding site of the visual pigment chromophore, the 11-cis-retinal. The best 24 virtual hits were examined for their ability to compete for the chromophore-binding site of opsin. Among these, four small molecules demonstrated the ability to reduce the rate constant for the formation of the 9-cis-retinal-rhodopsin complex, while five molecules surprisingly enhanced the formation of this complex. Compound 7, 13, 20 and 23 showed a weak but detectable increase in the trafficking of the P23H mutant, widely used as a model for both retinitis pigmentosa and Leber’s congenital amaurosis, from the ER to the cell membrane. The compounds did not show any relevant cytotoxicity in two different human cell lines, with the only exception of 13. Based on the structures of these active compounds, a series of in silico studies gave important insights on the potential structural features required for a molecule to act either as chemical chaperone or as stabiliser of the 11-cis-retinal-rhodopsin complex. Thus, this study revealed a series of small molecules that represent a solid foundation for the future development of novel therapeutics against these severe inherited blinding diseases.
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Affiliation(s)
- Gaia Pasqualetto
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK; (G.P.); (C.V.); (E.P.)
| | - Martin Schepelmann
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, 1090 Vienna, Austria;
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK; (C.K.); (S.R.M.); (I.B.); (M.R.)
| | - Carmine Varricchio
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK; (G.P.); (C.V.); (E.P.)
| | - Elisa Pileggi
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK; (G.P.); (C.V.); (E.P.)
| | - Caroline Khogali
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK; (C.K.); (S.R.M.); (I.B.); (M.R.)
| | - Siân R. Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK; (C.K.); (S.R.M.); (I.B.); (M.R.)
- Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff CF10 3NB, UK
| | - Ian Boostrom
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK; (C.K.); (S.R.M.); (I.B.); (M.R.)
| | - Malgorzata Rozanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK; (C.K.); (S.R.M.); (I.B.); (M.R.)
- Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff CF10 3NB, UK
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK; (G.P.); (C.V.); (E.P.)
- Correspondence:
| | - Salvatore Ferla
- Swansea University Medical School, Institute of Life Sciences 2, Swansea University, Swansea SA2 8PP, UK;
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25
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Cioffi CL, Muthuraman P, Raja A, Varadi A, Racz B, Petrukhin K. Discovery of Bispecific Antagonists of Retinol Binding Protein 4 That Stabilize Transthyretin Tetramers: Scaffolding Hopping, Optimization, and Preclinical Pharmacological Evaluation as a Potential Therapy for Two Common Age-Related Comorbidities. J Med Chem 2020; 63:11054-11084. [DOI: 10.1021/acs.jmedchem.0c00996] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Christopher L. Cioffi
- Departments of Basic and Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, New York 12208, United States
| | - Parthasarathy Muthuraman
- Departments of Basic and Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, New York 12208, United States
| | - Arun Raja
- Departments of Basic and Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, New York 12208, United States
| | - Andras Varadi
- Department of Ophthalmology, Columbia University Medical Center, New York, New York 10032, United States
| | - Boglarka Racz
- Department of Ophthalmology, Columbia University Medical Center, New York, New York 10032, United States
| | - Konstantin Petrukhin
- Department of Ophthalmology, Columbia University Medical Center, New York, New York 10032, United States
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26
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Racz B, Varadi A, Pearson PG, Petrukhin K. Comparative pharmacokinetics and pharmacodynamics of the advanced Retinol-Binding Protein 4 antagonist in dog and cynomolgus monkey. PLoS One 2020; 15:e0228291. [PMID: 31978148 PMCID: PMC6980506 DOI: 10.1371/journal.pone.0228291] [Citation(s) in RCA: 5] [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: 08/09/2019] [Accepted: 01/10/2020] [Indexed: 12/23/2022] Open
Abstract
Accumulation of lipofuscin bisretinoids in the retina contributes to pathogenesis of macular degeneration. Retinol-Binding Protein 4 (RBP4) antagonists reduce serum retinol concentrations thus partially reducing retinol delivery to the retina which decreases bisretinoid synthesis. BPN-14136 is a novel RBP4 antagonist with good in vitro potency and selectivity and optimal rodent pharmacokinetic (PK) and pharmacodynamic (PD) characteristics. To select a non-rodent species for regulatory toxicology studies, we conducted PK and PD evaluation of BPN-14136 in dogs and non-human primates (NHP). PK properties were determined following oral and intravenous administration of BPN-14136 in beagle dogs and cynomolgus monkeys. Dynamics of plasma RBP4 reduction in response to compound administration was used as a PD marker. BPN-14136 exhibited favorable PK profile in both species. Dose-normalized exposure was significantly higher in NHP than in dog. Baseline concentrations of RBP4 were considerably lower in dog than in NHP, reflecting the atypical reliance of canids on non-RBP4 mechanisms of retinoid trafficking. Oral administration of BPN-14136 to NHP induced a strong 99% serum RBP4 reduction. Dynamics of RBP4 lowering in both species correlated with compound exposure. Despite adequate PK and PD characteristics of BPN-14136 in dog, reliance of canids on non-RBP4 mechanisms of retinoid trafficking precludes evaluation of on-target toxicities for RBP4 antagonists in this species. Strong RBP4 lowering combined with good PK attributes and high BPN-14136 exposure achieved in NHP, along with the biology of retinoid trafficking that is similar to that of humans, support the choice of NHP as a non-rodent safety species.
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Affiliation(s)
- Boglarka Racz
- Department of Ophthalmology, Columbia University, New York, New York, Unites States of America
| | - Andras Varadi
- Department of Ophthalmology, Columbia University, New York, New York, Unites States of America
| | - Paul G. Pearson
- Pearson Pharma Partners, Westlake Village, California, United States of America
| | - Konstantin Petrukhin
- Department of Ophthalmology, Columbia University, New York, New York, Unites States of America
- * E-mail:
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Ahmed CM, Dwyer BT, Romashko A, Van Adestine S, Park EH, Lou Z, Welty D, Josiah S, Savinainen A, Zhang B, Lewin AS. SRD005825 Acts as a Pharmacologic Chaperone of Opsin and Promotes Survival of Photoreceptors in an Animal Model of Autosomal Dominant Retinitis Pigmentosa. Transl Vis Sci Technol 2019; 8:30. [PMID: 31857914 PMCID: PMC6910612 DOI: 10.1167/tvst.8.6.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 10/11/2019] [Indexed: 01/17/2023] Open
Abstract
Purpose Mutations in RHO, the gene for a rhodopsin, are a leading cause of autosomal dominant retinitis pigmentosa. The objective of this study was to determine if a synthetic retinal analogue (SRD005825) serves as a pharmacologic chaperone to promote appropriate membrane trafficking of a mutant version of human rhodopsin. Methods A tetracycline-inducible cell line was used to produce human wild-type and T17M opsin. A cell-free assay was used to study the impact of SRD005825 on binding of 9-cis-retinal to wild-type opsin. A cell-based assay was used to measure the effect of SRD005825 on the generation of rhodopsin by spectroscopy and Western blot and the transport of rhodopsin to the cell membrane by confocal microscopy. Mice bearing T17M RHO were treated with daily oral doses of SRD005825, and retinal degeneration was measured by spectral-domain optical coherence tomography and, at the conclusion of the experiment, by electroretinography and morphometry. Results SRD005825 competed with 9-cis-retinal for binding to wild-type opsin but promoted the formation of rhodopsin in HEK293 cells and the trafficking of T17M rhodopsin to the plasma membrane of these cells. T17M transgenic mice exhibited rapid retinal degeneration, but thinning of the outer nuclear layer representative of photoreceptor cell bodies was delayed by treatment with SRD005825. Electroretinography a-wave and b-wave amplitudes were significantly improved by drug treatment. Conclusions SRD005825 promoted the reconstitution of mutant rhodopsin and its membrane localization. Because it delayed retinal degeneration in the mouse model, it has potential as a therapeutic for autosomal dominant retinitis pigmentosa. Translational Relevance SRD005825 may be useful as a treatment to delay retinal degeneration in retinitis pigmentosa patients with rhodopsin mutations causing misfolding of the protein.
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Affiliation(s)
- Chulbul M Ahmed
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Brian T Dwyer
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | - All Romashko
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | | | - Eun-He Park
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | - Zhe Lou
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | - Devi Welty
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | - Seren Josiah
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | - Annel Savinainen
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | - Bohon Zhang
- Shire HGT Inc., a member of the Takeda group of companies, Cambridge, MA, USA
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
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Keshmiri Neghab H, Goliaei B, Saboury AA, Esmaeeli Djavid G, Pornour M, Hong J, Grusch M. Modulation of cardiac optogenetics by vitamin A. Biofactors 2019; 45:983-990. [PMID: 31509323 DOI: 10.1002/biof.1564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 08/16/2019] [Indexed: 01/03/2023]
Abstract
Cardiac optogenetics is an emergent research area and refers to the delivery of light-activated proteins to excitable heart tissue and the subsequent use of light for controlling the electrical function with high spatial and temporal resolution. Channelrhodopsin-2 (ChR2) is a light-sensitive ion channel with the chromophore, all trans retinal, derived from vitamin A (all-trans-retinol; retinol). In this study, we explored whether exogenous vitamin A can be a limiting factor in the light responsiveness of cardiomyocytes-expressing ChR2. We showed that in cardiomyocytes virally transduced with ChR2 (H134R)-enhanced yellow fluorescent protein, vitamin A supplements lower than 10 μM significantly increased ChR2 expression. Adding 1 μM vitamin A changed light-induced transmembrane potential difference significantly, whereas 5 μM dramatically induced membrane depolarization and triggered intracellular calcium elevation. We concluded that vitamin A supplementation can modulate the efficiency of ChR2 and provide a complementary strategy for improving the performance of optogenetic tools.
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Affiliation(s)
| | - Bahram Goliaei
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Ali A Saboury
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Gholamreza Esmaeeli Djavid
- Department of Photo Healing and Regeneration, Medical Laser Research Center, Yara Institute Academic Center for Education, Culture and Research (ACECR), Tehran, Iran
| | - Majid Pornour
- Department of Photo Healing and Regeneration, Medical Laser Research Center, Yara Institute Academic Center for Education, Culture and Research (ACECR), Tehran, Iran
| | - Jun Hong
- School of Life Sciences, Henan University, Kaifeng, China
| | - Michael Grusch
- Department of Medicine I, Comprehensive Cancer Center Vienna, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
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29
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Aggregate exposure modelling of vitamin A from cosmetic products, diet and food supplements. Food Chem Toxicol 2019; 131:110549. [DOI: 10.1016/j.fct.2019.05.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 05/14/2019] [Accepted: 05/30/2019] [Indexed: 11/23/2022]
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30
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Vázquez-Domínguez I, Garanto A, Collin RWJ. Molecular Therapies for Inherited Retinal Diseases-Current Standing, Opportunities and Challenges. Genes (Basel) 2019; 10:genes10090654. [PMID: 31466352 PMCID: PMC6770110 DOI: 10.3390/genes10090654] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 12/15/2022] Open
Abstract
Inherited retinal diseases (IRDs) are both genetically and clinically highly heterogeneous and have long been considered incurable. Following the successful development of a gene augmentation therapy for biallelic RPE65-associated IRD, this view has changed. As a result, many different therapeutic approaches are currently being developed, in particular a large variety of molecular therapies. These are depending on the severity of the retinal degeneration, knowledge of the pathophysiological mechanism underlying each subtype of IRD, and the therapeutic target molecule. DNA therapies include approaches such as gene augmentation therapy, genome editing and optogenetics. For some genetic subtypes of IRD, RNA therapies and compound therapies have also shown considerable therapeutic potential. In this review, we summarize the current state-of-the-art of various therapeutic approaches, including the pros and cons of each strategy, and outline the future challenges that lie ahead in the combat against IRDs.
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Affiliation(s)
- Irene Vázquez-Domínguez
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands
| | - Alejandro Garanto
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
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31
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Retinal Gene Distribution and Functionality Implicated in Inherited Retinal Degenerations Can Reveal Disease-Relevant Pathways for Pharmacologic Intervention. Pharmaceuticals (Basel) 2019; 12:ph12020074. [PMID: 31108889 PMCID: PMC6631933 DOI: 10.3390/ph12020074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/08/2019] [Accepted: 05/15/2019] [Indexed: 01/17/2023] Open
Abstract
The advent of genetic therapies for inherited retinal diseases (IRDs) has spurred the need for precise diagnosis and understanding of pathways for therapeutic targeting. The majority of IRDs that are clinically diagnosed, however, lack an identifiable mutation in established disease-causing loci and thus can be investigated with limited rational drug discovery methods. Transcriptome profiling of the retina can reveal the functional state of the tissue, and geographic profiling can uncover the various clinical phenotypic presentations of IRDs and aid in pharmaceutical intervention. In this investigation, we detail the retinal geographic expression of known retinal disease-causing genes in the primate retina and functional targetable pathways in specific IRDs. Understanding the genetic basis as well as the resulting functional consequences will assist in the discovery of future therapeutic interventions and provide novel insights to medicinal chemists. Herein, we report that, despite the genetic heterogeneity of retinal diseases, potential functional pathways can be elucidated for therapeutic targeting and be used for predictive phenotypic and genotypic modeling of novel IRD presentations.
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Galván I, Murtada K, Jorge A, Ríos Á, Zougagh M. Unique evolution of vitamin A as an external pigment in tropical starlings. J Exp Biol 2019; 222:jeb.205229. [DOI: 10.1242/jeb.205229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 05/11/2019] [Indexed: 01/03/2023]
Abstract
Pigments are largely responsible for the appearance of organisms. Most biological pigments derive from the metabolism of shikimic acid (melanins), mevalonic acid (carotenoids) or levulinic acid (porphyrins), which thus generate the observed diversity of external phenotypes. Starlings are generally dark birds despite iridescence in feathers, but 10 % of species have evolved plumage pigmentation comprising bright colors that are known to be produced only by carotenoids. However, using micro-Raman spectroscopy, we have discovered that the bright yellow plumage coloration of one of these species, the Afrotropical golden-breasted starling Cosmopsarus regius, is not produced by carotenoids, but by vitamin A (all-trans-retinol). This is the first organism reported to deposit significant amounts of vitamin A in its integument and use it as a body pigment. Phylogenetic reconstructions reveal that the retinol-based pigmentation of the golden-breasted starling has independently appeared in the starling family from dark ancestors. Our study thus unveils a unique evolution of a new class of external pigments comprised by retinoids.
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Affiliation(s)
- Ismael Galván
- Department of Evolutionary Ecology, Doñana Biological Station, Consejo Superior de Investigaciones Científicas (CSIC), 41092 Sevilla, Spain
| | - Khaled Murtada
- Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, 13071 Ciudad Real, Spain
- Department of Analytical Chemistry and Food Technology, Faculty of Chemical Science and Technology, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Alberto Jorge
- Laboratory of Non-Invasive Analytical Techniques, National Museum of Natural Sciences, Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
| | - Ángel Ríos
- Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, 13071 Ciudad Real, Spain
- Department of Analytical Chemistry and Food Technology, Faculty of Chemical Science and Technology, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Mohammed Zougagh
- Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, 13071 Ciudad Real, Spain
- Department of Analytical Chemistry and Food Technology, Faculty of Pharmacy, University of Castilla-La Mancha, 02071 Albacete, Spain
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Gao S, Parmar T, Palczewska G, Dong Z, Golczak M, Palczewski K, Jastrzebska B. Protective Effect of a Locked Retinal Chromophore Analog against Light-Induced Retinal Degeneration. Mol Pharmacol 2018; 94:1132-1144. [PMID: 30018116 DOI: 10.1124/mol.118.112581] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/11/2018] [Indexed: 01/10/2023] Open
Abstract
Continuous regeneration of the 11-cis-retinal visual chromophore from all-trans-retinal is critical for vision. Insufficiency of 11-cis-retinal arising from the dysfunction of key proteins involved in its regeneration can impair retinal health, ultimately leading to loss of human sight. Delayed recovery of visual sensitivity and night blindness caused by inadequate regeneration of the visual pigment rhodopsin are typical early signs of this condition. Excessive concentrations of unliganded, constitutively active opsin and increased levels of all-trans-retinal and its byproducts in photoreceptors also accelerate retinal degeneration after light exposure. Exogenous 9-cis-retinal iso-chromophore can reduce the toxicity of ligand-free opsin but fails to prevent the buildup of retinoid photoproducts when their clearance is defective in human retinopathies, such as Stargardt disease or age-related macular degeneration. Here we evaluated the effect of a locked chromophore analog, 11-cis-6-membered ring-retinal against bright light-induced retinal degeneration in Abca4-/-Rdh8-/- mice. Using in vivo imaging techniques, optical coherence tomography, scanning laser ophthalmoscopy, and two-photon microscopy, along with in vitro histologic analysis of retinal morphology, we found that treatment with 11-cis-6-membered ring-retinal before light stimulation prevented rod and cone photoreceptor degradation and preserved functional acuity in these mice. Moreover, additive accumulation of 11-cis-6-membered ring-retinal measured in the eyes of these mice by quantitative liquid chromatography-mass spectrometry indicated stable binding of this retinoid to opsin. Together, these results suggest that eliminating excess of unliganded opsin can prevent light-induced retinal degeneration in Abca4-/-Rdh8-/- mice.
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Affiliation(s)
- Songqi Gao
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Tanu Parmar
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Grazyna Palczewska
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Zhiqian Dong
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Marcin Golczak
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Beata Jastrzebska
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
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Racz B, Varadi A, Kong J, Allikmets R, Pearson PG, Johnson G, Cioffi CL, Petrukhin K. A non-retinoid antagonist of retinol-binding protein 4 rescues phenotype in a model of Stargardt disease without inhibiting the visual cycle. J Biol Chem 2018; 293:11574-11588. [PMID: 29871924 DOI: 10.1074/jbc.ra118.002062] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 06/01/2018] [Indexed: 12/11/2022] Open
Abstract
A primary pathological defect in the heritable eye disorder Stargardt disease is excessive accumulation of cytotoxic lipofuscin bisretinoids in the retina. Age-dependent accumulation of lipofuscin in the retinal pigment epithelium (RPE) matches the age-dependent increase in the incidence of the atrophic (dry) form of age-related macular degeneration (AMD) and therefore may be one of several pathogenic factors contributing to AMD progression. Lipofuscin bisretinoid synthesis in the retina depends on the influx of serum retinol from the circulation into the RPE. Formation of the tertiary retinol-binding protein 4 (RBP4)-transthyretin-retinol complex in the serum is required for this influx. Herein, we report the pharmacological effects of the non-retinoid RBP4 antagonist, BPN-14136. BPN-14136 dosing in the Abca4-/- mouse model of increased lipofuscinogenesis significantly reduced serum RBP4 levels and inhibited bisretinoid synthesis, and this inhibition correlated with a partial reduction in visual cycle retinoids such as retinaldehydes serving as bisretinoid precursors. BPN-14136 administration at doses inducing maximal serum RBP4 reduction did not produce changes in the rate of the visual cycle, consistent with minimal changes in dark adaptation. Abca4-/- mice exhibited dysregulation of the complement system in the retina, and BPN-14136 administration normalized the retinal levels of proinflammatory complement cascade components such as complement factors D and H, C-reactive protein, and C3. We conclude that BPN-14136 has several beneficial characteristics, combining inhibition of bisretinoid synthesis and reduction in retinaldehydes with normalization of the retinal complement system. BPN-14136, or a similar compound, may be a promising drug candidate to manage Stargardt disease and dry AMD.
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Affiliation(s)
- Boglarka Racz
- Department of Ophthalmology, Columbia University, New York, New York 10032
| | - Andras Varadi
- Department of Ophthalmology, Columbia University, New York, New York 10032
| | - Jian Kong
- Department of Ophthalmology, Columbia University, New York, New York 10032
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, New York 10032; Department of Pathology and Cell Biology, Columbia University, New York, New York 10032
| | - Paul G Pearson
- Pearson Pharma Partners, Westlake Village, California 91361
| | | | - Christopher L Cioffi
- Departments of Basic and Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208
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Behnen P, Felline A, Comitato A, Di Salvo MT, Raimondi F, Gulati S, Kahremany S, Palczewski K, Marigo V, Fanelli F. A Small Chaperone Improves Folding and Routing of Rhodopsin Mutants Linked to Inherited Blindness. iScience 2018; 4:1-19. [PMID: 30240733 PMCID: PMC6147235 DOI: 10.1016/j.isci.2018.05.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/06/2018] [Accepted: 04/30/2018] [Indexed: 11/24/2022] Open
Abstract
The autosomal dominant form of retinitis pigmentosa (adRP) is a blindness-causing conformational disease largely linked to mutations of rhodopsin. Molecular simulations coupled to the graph-based protein structure network (PSN) analysis and in vitro experiments were conducted to determine the effects of 33 adRP rhodopsin mutations on the structure and routing of the opsin protein. The integration of atomic and subcellular levels of analysis was accomplished by the linear correlation between indices of mutational impairment in structure network and in routing. The graph-based index of structural perturbation served also to divide the mutants in four clusters, consistent with their differences in subcellular localization and responses to 9-cis retinal. The stability core of opsin inferred from PSN analysis was targeted by virtual screening of over 300,000 anionic compounds leading to the discovery of a reversible orthosteric inhibitor of retinal binding more effective than retinal in improving routing of three adRP mutants. In silico and in vitro analyses of adRP rhodopsin mutants bridged folding and routing Structure network analysis grouped mutants amenable to treatment with small chaperones Virtual compound screening against the stability core of opsin found a small chaperone The pharmacoperone is a reversible orthosteric inhibitor of retinal binding
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Affiliation(s)
- Petra Behnen
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Angelo Felline
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy
| | - Antonella Comitato
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Maria Teresa Di Salvo
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Francesco Raimondi
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy
| | - Sahil Gulati
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, 1819 East 101st Street, Cleveland, OH 44106, USA
| | - Shirin Kahremany
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, 1819 East 101st Street, Cleveland, OH 44106, USA
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy; Center for Neuroscience and Neurotechnology, via Campi 287, 41125 Modena, Italy.
| | - Francesca Fanelli
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy; Center for Neuroscience and Neurotechnology, via Campi 287, 41125 Modena, Italy.
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Abstract
PURPOSE To identify changes in the outer retina in areas without atrophy or flecks of Stargardt disease (STGD) using spectral-domain optical coherence tomography. METHODS Twenty-three STGD patients and 26 control subjects were assessed for outer retina (from the outer border of Bruch membrane [BrM] to the inner border of the inner segment ellipsoid zone [EZ]), BrM-retinal pigment epithelium apex, the EZ thickness, and apical process interdigitation zone. RESULTS Patients with STGD had increased BrM-EZ thickness in areas without apparent disease versus control subjects at 1,000, 1,500, 2,000, and 2,500 μm superior and 1,500 μm, 2,000 μm, and 2,500 μm inferior to the fovea (P < 0.05 to P < 0.001), greatest difference (3.4 μm) at 2,500 μm superiorly. The BrM-retinal pigment epithelium segment showed larger fractional contribution of 0.48 to 0.51 to the overall BrM-EZ thickness compared with 0.35 to 0.42 in control subjects. The thickness of EZ and the interspace between the retinal pigment epithelium apex and EZ were smaller in the STGD patients (P < 0.05 to P < 0.001). Patients with STGD displayed an interrupted interdigitation zone in 16 (84.2%) of 19 eyes versus 6 (23.1%) of 26 eyes of the control subjects (P < 0.001). The BrM-EZ segment of the outer retina of STGD patients lacked the typical normal trilaminar pattern. CONCLUSION Subtle changes are present within the BrM-EZ segment of the outer retina of STGD patients in areas that are devoid of atrophy and flecks. These findings suggest that pathologic changes in STGD are more widespread than that seen by clinical examination.
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Kaarniranta K, Xu H, Kauppinen A. Mechanistical retinal drug targets and challenges. Adv Drug Deliv Rev 2018; 126:177-184. [PMID: 29698626 DOI: 10.1016/j.addr.2018.04.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/27/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022]
Abstract
The retina is constantly exposed to light that increases reactive oxygen species in retina. Oxidative stress, inflammation and neurodegeneration are the major contributors in the most common retinal diseases, such as age-related macular degeneration (AMD), glaucoma and diabetic retinopathy (DR). Emerging developments and research for novel therapy targets and drug delivery to the posterior segment offer a promising future for the treatment of retinal diseases including rare hereditary diseases. In this review we discuss about promising mechanistical retinal drug targets. Vascular endothelial growth factor (VEGF) signaling and anti-VEGF treatments are excluded.
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Kiser PD, Zhang J, Badiee M, Kinoshita J, Peachey NS, Tochtrop GP, Palczewski K. Rational Tuning of Visual Cycle Modulator Pharmacodynamics. J Pharmacol Exp Ther 2017; 362:131-145. [PMID: 28476927 DOI: 10.1124/jpet.117.240721] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 05/01/2017] [Indexed: 11/22/2022] Open
Abstract
Modulators of the visual cycle have been developed for treatment of various retinal disorders. These agents were designed to inhibit retinoid isomerase [retinal pigment epithelium-specific 65 kDa protein (RPE65)], the rate-limiting enzyme of the visual cycle, based on the idea that attenuation of visual pigment regeneration could reduce formation of toxic retinal conjugates. Of these agents, certain ones that contain primary amine groups can also reversibly form retinaldehyde Schiff base adducts, which contributes to their retinal protective activity. Direct inhibition of RPE65 as a therapeutic strategy is complicated by adverse effects resulting from slowed chromophore regeneration, whereas effective retinal sequestration can require high drug doses with potential off-target effects. We hypothesized that the RPE65-emixustat crystal structure could help guide the design of retinaldehyde-sequestering agents with varying degrees of RPE65 inhibitory activity. We found that addition of an isopropyl group to the central phenyl ring of emixustat and related compounds resulted in agents effectively lacking in vitro retinoid isomerase inhibitory activity, whereas substitution of the terminal 6-membered ring with branched moieties capable of stronger RPE65 interaction potentiated inhibition. The isopropyl derivative series produced discernible visual cycle suppression in vivo, albeit much less potently than compounds with a high affinity for the RPE65 active site. These agents were distributed into the retina and formed Schiff base adducts with retinaldehyde. Except for one compound [3-amino-1-(3-isopropyl-5-((2,6,6-trimethylcyclohex-1-en-1-yl)methoxy)phenyl)propan-1-ol (MB-007)], these agents conferred protection against retinal phototoxicity, suggesting that both direct RPE65 inhibition and retinal sequestration are mechanisms of potential therapeutic relevance.
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Affiliation(s)
- Philip D Kiser
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Jianye Zhang
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Mohsen Badiee
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Junzo Kinoshita
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Neal S Peachey
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Gregory P Tochtrop
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine (P.D.K., J.Z., K.P.), Department of Chemistry (M.B., G.P.T.), Case Western Reserve University, Cleveland, Ohio; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio (P.D.K., N.S.P.); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (J.K., N.S.P.); and Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio (N.S.P.)
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Arai E, Parmar VM, Sahu B, Perusek L, Parmar T, Maeda A. Docosahexaenoic acid promotes differentiation of photoreceptor cells in three-dimensional neural retinas. Neurosci Res 2017; 123:1-7. [PMID: 28433627 DOI: 10.1016/j.neures.2017.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 04/11/2017] [Accepted: 04/14/2017] [Indexed: 01/10/2023]
Abstract
Retinal tissues generated from human pluripotent stem cells can be an excellent tool for investigating pathogenesis of retinal diseases and developing new pharmacologic therapies. Moreover, patient derived retinal tissues could allow for retinal transplantation therapy for degenerative retinal diseases. However, obtaining retinal tissues with matured photoreceptor outer segments, which are essential for photoreceptor functions, is currently challenging. Here we investigated the effects of docosahexaenoic acid (DHA) for maturation of photoreceptor outer segments at the late stage and visual chromophore analog, 9-cis-retinal for the early stage of differentiation to three-dimensional (3D)-retinal tissues from human embryonic stem cells (hESCs), respectively. In the presence of DHA, differentiated 3D-retinal tissues demonstrated improved maturation of photoreceptor outer segments and increased number of photoreceptor cells compared with tissues without DHA. Increased mRNA expression of mature photoreceptor markers was additionally documented in retinal tissues cultured with DHA. Conversely supplementation with 9-cis-retinal failed to improve differentiation of retinal tissues perhaps due to chronic aldehyde toxicity. The current study demonstrated that the addition of DHA to culture medium can help promote differentiation of photoreceptor outer segments in vitro and utilization of this methodology may lead to future therapies for patients with blinding diseases.
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Affiliation(s)
- Eisuke Arai
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Vipul M Parmar
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Bhubanananda Sahu
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Lindsay Perusek
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Tanu Parmar
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Akiko Maeda
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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Molecular Basis for Vitamin A Uptake and Storage in Vertebrates. Nutrients 2016; 8:nu8110676. [PMID: 27792183 PMCID: PMC5133064 DOI: 10.3390/nu8110676] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 09/30/2016] [Accepted: 10/18/2016] [Indexed: 01/27/2023] Open
Abstract
The ability to store and distribute vitamin A inside the body is the main evolutionary adaptation that allows vertebrates to maintain retinoid functions during nutritional deficiencies and to acquire new metabolic pathways enabling light-independent production of 11-cis retinoids. These processes greatly depend on enzymes that esterify vitamin A as well as associated retinoid binding proteins. Although the significance of retinyl esters for vitamin A homeostasis is well established, until recently, the molecular basis for the retinol esterification enzymatic activity was unknown. In this review, we will look at retinoid absorption through the prism of current biochemical and structural studies on vitamin A esterifying enzymes. We describe molecular adaptations that enable retinoid storage and delineate mechanisms in which mutations found in selective proteins might influence vitamin A homeostasis in affected patients.
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Abstract
Recent progress in molecular understanding of the retinoid cycle in mammalian retina stems from painstaking biochemical reconstitution studies supported by natural or engineered animal models with known genetic lesions and studies of humans with specific genetic blinding diseases. Structural and membrane biology have been used to detect critical retinal enzymes and proteins and their substrates and ligands, placing them in a cellular context. These studies have been supplemented by analytical chemistry methods that have identified small molecules by their spectral characteristics, often in conjunction with the evaluation of models of animal retinal disease. It is from this background that rational therapeutic interventions to correct genetic defects or environmental insults are identified. Thus, most presently accepted modulators of the retinoid cycle already have demonstrated promising results in animal models of retinal degeneration. These encouraging signs indicate that some human blinding diseases can be alleviated by pharmacological interventions.
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Affiliation(s)
- Philip D Kiser
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106 ; Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio 44106
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
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Sears AE, Palczewski K. Lecithin:Retinol Acyltransferase: A Key Enzyme Involved in the Retinoid (visual) Cycle. Biochemistry 2016; 55:3082-91. [PMID: 27183166 DOI: 10.1021/acs.biochem.6b00319] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lecithin:retinol acyltransferase (LRAT) catalyzes the acyl transfer from the sn-1 position of phosphatidylcholine (PC) to all-trans-retinol, creating fatty acid retinyl esters (palmitoyl, stearoyl, and some unsaturated derivatives). In the eye, these retinyl esters are substrates for the 65 kDa retinoid isomerase (RPE65). LRAT is well characterized biochemically, and recent structural data from closely related family members of the NlpC/P60 superfamily and a chimeric protein have established its catalytic mechanism. Mutations in the LRAT gene are responsible for approximately 1% of reported cases of Leber congenital amaurosis (LCA). Lack of functional LRAT, expressed in the retinal pigmented epithelium (RPE), results in loss of the visual chromophore and photoreceptor degeneration. LCA is a rare hereditary retinal dystrophy with an early onset associated with mutations in one of 21 known genes. Protocols have been devised to identify therapeutics that compensate for mutations in RPE65, also associated with LCA. The same protocols can be adapted to combat dystrophies associated with LRAT. Improvement in the visual function of clinical recipients of therapy with recombinant adeno-associated virus (rAAV) vectors incorporating the RPE65 gene provides a proof of concept for LRAT, which functions in the same cell type and metabolic pathway as RPE65. In parallel, a clinical trial that employs oral 9-cis-retinyl acetate to replace the missing chromophore in RPE65 and LRAT causative disease has proven to be effective and free of adverse effects. This article summarizes the biochemistry of LRAT and examines chromophore replacement as a treatment for LCA caused by LRAT mutations.
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Affiliation(s)
- Avery E Sears
- Cleveland Center for Membrane and Structural Biology, Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Krzysztof Palczewski
- Cleveland Center for Membrane and Structural Biology, Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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Abstract
Visual systems detect light by monitoring the effect of photoisomerization of a chromophore on the release of a neurotransmitter from sensory neurons, known as rod and cone photoreceptor cells in vertebrate retina. In all known visual systems, the chromophore is 11-cis-retinal complexed with a protein, called opsin, and photoisomerization produces all-trans-retinal. In mammals, regeneration of 11-cis-retinal following photoisomerization occurs by a thermally driven isomerization reaction. Additional reactions are required during regeneration to protect cells from the toxicity of aldehyde forms of vitamin A that are essential to the visual process. Photochemical and phototransduction reactions in rods and cones are identical; however, reactions of the rod and cone visual pigment regeneration cycles differ, and perplexingly, rod and cone regeneration cycles appear to use different mechanisms to overcome the energy barrier involved in converting all-trans- to 11-cis-retinoid. Abnormal processing of all-trans-retinal in the rod regeneration cycle leads to retinal degeneration, suggesting that excessive amounts of the retinoid itself or its derivatives are toxic. This line of reasoning led to the development of various approaches to modifying the activity of the rod visual cycle as a possible therapeutic approach to delay or prevent retinal degeneration in inherited retinal diseases and perhaps in the dry form of macular degeneration (geographic atrophy). In spite of great progress in understanding the functioning of rod and cone regeneration cycles at a molecular level, resolution of a number of remaining puzzling issues will offer insight into the amelioration of several blinding retinal diseases.
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Stiles M, Moiseyev GP, Budda ML, Linens A, Brush RS, Qi H, White GL, Wolf RF, Ma JX, Floyd R, Anderson RE, Mandal NA. PBN (Phenyl-N-Tert-Butylnitrone)-Derivatives Are Effective in Slowing the Visual Cycle and Rhodopsin Regeneration and in Protecting the Retina from Light-Induced Damage. PLoS One 2015; 10:e0145305. [PMID: 26694648 PMCID: PMC4687940 DOI: 10.1371/journal.pone.0145305] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 12/02/2015] [Indexed: 11/18/2022] Open
Abstract
A2E and related toxic molecules are part of lipofuscin found in the retinal pigment epithelial (RPE) cells in eyes affected by Stargardt's disease, age-related macular degeneration (AMD), and other retinal degenerations. A novel therapeutic approach for treating such degenerations involves slowing down the visual cycle, which could reduce the amount of A2E in the RPE. This can be accomplished by inhibiting RPE65, which produces 11-cis-retinol from all-trans-retinyl esters. We recently showed that phenyl-N-tert-butylnitrone (PBN) inhibits RPE65 enzyme activity in RPE cells. In this study we show that like PBN, certain PBN-derivatives (PBNDs) such as 4-F-PBN, 4-CF3-PBN, 3,4-di-F-PBN, and 4-CH3-PBN can inhibit RPE65 and synthesis of 11-cis-retinol in in vitro assays using bovine RPE microsomes. We further demonstrate that systemic (intraperitoneal, IP) administration of these PBNDs protect the rat retina from light damage. Electroretinography (ERG) and histological analysis showed that rats treated with PBNDs retained ~90% of their photoreceptor cells compared to a complete loss of function and 90% loss of photoreceptors in the central retina in rats treated with vehicle/control injections. Topically applied PBN and PBNDs also significantly slowed the rate of the visual cycle in mouse and baboon eyes. One hour dark adaptation resulted in 75-80% recovery of bleachable rhodopsin in control/vehicle treated mice. Eye drops of 5% 4-CH3-PBN were most effective, inhibiting the regeneration of bleachable rhodopsin significantly (60% compared to vehicle control). In addition, a 10% concentration of PBN and 5% concentration of 4-CH3-PBN in baboon eyes inhibited the visual cycle by 60% and by 30%, respectively. We have identified a group of PBN related nitrones that can reach the target tissue (RPE) by systemic and topical application and slow the rate of rhodopsin regeneration and therefore the visual cycle in mouse and baboon eyes. PBNDs can also protect the rat retina from light damage. There is potential in developing these compounds as preventative therapeutics for the treatment of human retinal degenerations in which the accumulation of lipofuscin may be pathogenic.
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Affiliation(s)
- Megan Stiles
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Gennadiy P. Moiseyev
- Department of Physiology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Madeline L. Budda
- Department of Cell Biology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Annette Linens
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Richard S. Brush
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Hui Qi
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Gary L. White
- Department of Pathology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Roman F. Wolf
- Department of Pathology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Jian-xing Ma
- Department of Physiology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Endocrinology and Diabetes, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Robert Floyd
- Experimental Therapeutics, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Robert E. Anderson
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Pathology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Nawajes A. Mandal
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Cell Biology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Endocrinology and Diabetes, OUHSC, Oklahoma City, Oklahoma, United States of America
- Oklahoma Center for Neuroscience, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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Scholl HPN, Moore AT, Koenekoop RK, Wen Y, Fishman GA, van den Born LI, Bittner A, Bowles K, Fletcher EC, Collison FT, Dagnelie G, Degli Eposti S, Michaelides M, Saperstein DA, Schuchard RA, Barnes C, Zein W, Zobor D, Birch DG, Mendola JD, Zrenner E. Safety and Proof-of-Concept Study of Oral QLT091001 in Retinitis Pigmentosa Due to Inherited Deficiencies of Retinal Pigment Epithelial 65 Protein (RPE65) or Lecithin:Retinol Acyltransferase (LRAT). PLoS One 2015; 10:e0143846. [PMID: 26656277 PMCID: PMC4687523 DOI: 10.1371/journal.pone.0143846] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 10/29/2015] [Indexed: 11/30/2022] Open
Abstract
Restoring vision in inherited retinal degenerations remains an unmet medical need. In mice exhibiting a genetically engineered block of the visual cycle, vision was recently successfully restored by oral administration of 9-cis-retinyl acetate (QLT091001). Safety and visual outcomes of a once-daily oral dose of 40 mg/m2/day QLT091001 for 7 consecutive days was investigated in an international, multi-center, open-label, proof-of-concept study in 18 patients with RPE65- or LRAT-related retinitis pigmentosa. Eight of 18 patients (44%) showed a ≥20% increase and 4 of 18 (22%) showed a ≥40% increase in functional retinal area determined from Goldmann visual fields; 12 (67%) and 5 (28%) of 18 patients showed a ≥5 and ≥10 ETDRS letter score increase of visual acuity, respectively, in one or both eyes at two or more visits within 2 months of treatment. In two patients who underwent fMRI, a significant positive response was measured to stimuli of medium contrast, moving, pattern targets in both left and right hemispheres of the occipital cortex. There were no serious adverse events. Treatment-related adverse events were transient and the most common included headache, photophobia, nausea, vomiting, and minor biochemical abnormalities. Measuring the outer segment length of the photoreceptor layer with high-definition optical coherence tomography was highly predictive of treatment responses with responders having a significantly larger baseline outer segment thickness (11.7 ± 4.8 μm, mean ± 95% CI) than non-responders (3.5 ± 1.2 μm). This structure-function relationship suggests that treatment with QLT091001 is more likely to be efficacious if there is sufficient photoreceptor integrity.
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Affiliation(s)
- Hendrik P. N. Scholl
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail:
| | - Anthony T. Moore
- Moorfields Eye Hospital and Institute of Ophthalmology, University College London, London, United Kingdom
- Dept. of Ophthalmology, University of California San Francisco, San Francisco, CA, United States of America
| | | | - Yuquan Wen
- Retina Foundation of the Southwest, Dallas, TX, United States of America
- Baylor Visual Function Center, Baylor University Medical Center, Dallas, TX, United States of America
| | - Gerald A. Fishman
- Chicago Lighthouse, Pangere Center for Inherited Retinal Diseases, Chicago, IL, United States of America
| | | | - Ava Bittner
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- Nova Southeastern University, College of Optometry, Fort Lauderdale, FL, United States of America
| | - Kristen Bowles
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- College of Optometry, University of Houston, Houston, TX, United States of America
| | - Emily C. Fletcher
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- Gloucester Royal NHS Foundation Trust, Gloucester Royal Hospitals, Gloucester, United Kingdom
| | - Frederick T. Collison
- Chicago Lighthouse, Pangere Center for Inherited Retinal Diseases, Chicago, IL, United States of America
| | - Gislin Dagnelie
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
| | - Simona Degli Eposti
- Moorfields Eye Hospital and Institute of Ophthalmology, University College London, London, United Kingdom
| | - Michel Michaelides
- Moorfields Eye Hospital and Institute of Ophthalmology, University College London, London, United Kingdom
| | - David A. Saperstein
- Vitreoretinal Associates of Washington, Seattle, WA, United States of America
- QLT Inc., Vancouver, Canada
| | - Ronald A. Schuchard
- QLT Inc., Vancouver, Canada
- Stanford Univ School of Medicine, Palo Alto, CA, United States of America
| | - Claire Barnes
- QLT Inc., Vancouver, Canada
- VA Palo Alto Health Care System, Palo Alto, CA, United States of America
| | - Wadih Zein
- Division of Epidemiology and Clinical Research, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Ditta Zobor
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - David G. Birch
- Retina Foundation of the Southwest, Dallas, TX, United States of America
- Ophthalmology, UT Southwestern, Dallas, TX, United States of America
| | | | - Eberhart Zrenner
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
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Cardiac Optogenetics: Enhancement by All-trans-Retinal. Sci Rep 2015; 5:16542. [PMID: 26568132 PMCID: PMC4644984 DOI: 10.1038/srep16542] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 10/15/2015] [Indexed: 11/30/2022] Open
Abstract
All-trans-Retinal (ATR) is a photosensitizer, serving as the chromophore for depolarizing and hyperpolarizing light-sensitive ion channels and pumps (opsins), recently employed as fast optical actuators. In mammalian optogenetic applications (in brain and heart), endogenous ATR availability is not considered a limiting factor, yet it is unclear how ATR modulation may affect the response to optical stimulation. We hypothesized that exogenous ATR may improve light responsiveness of cardiac cells modified by Channelrhodopsin2 (ChR2), hence lowering the optical pacing energy. In virally-transduced (Ad-ChR2(H134R)-eYFP) light-sensitive cardiac syncytium in vitro, ATR supplements ≤2 μM improved cardiomyocyte viability and augmented ChR2 membrane expression several-fold, while >4 μM was toxic. Employing integrated optical actuation (470 nm) and optical mapping, we found that 1–2 μM ATR dramatically reduced optical pacing energy (over 30 times) to several μW/mm2, lowest values reported to date, but also caused action potential prolongation, minor changes in calcium transients and no change in conduction. Theoretical analysis helped explain ATR-caused reduction of optical excitation threshold in cardiomyocytes. We conclude that cardiomyocytes operate at non-saturating retinal levels, and carefully-dosed exogenous ATR can enhance the performance of ChR2 in cardiac cells and yield energy benefits over orders of magnitude for optogenetic stimulation.
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Chen Y, Tang H, Seibel W, Papoian R, Li X, Lambert NA, Palczewski K. A High-Throughput Drug Screening Strategy for Detecting Rhodopsin P23H Mutant Rescue and Degradation. Invest Ophthalmol Vis Sci 2015; 56:2553-67. [PMID: 25783607 DOI: 10.1167/iovs.14-16298] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Inherent instability of the P23H mutant opsin accounts for approximately 10% of autosomal dominant retinitis pigmentosa cases. Our purpose was to develop an overall set of reliable screening strategies to assess if either stabilization or enhanced degradation of mutant rhodopsin could rescue rod photoreceptors expressing this mutant protein. These strategies promise to reveal active compounds and clarify molecular mechanisms of biologically important processes, such as inhibition of target degradation or enhanced target folding. METHODS Cell-based bioluminescence reporter assays were developed and validated for high-throughput screening (HTS) of compounds that promote either stabilization or degradation of P23H mutant opsin. Such assays were further complemented by immunoblotting and image-based analyses. RESULTS Two stabilization assays of P23H mutant opsin were developed and validated, one based on β-galactosidase complementarity and a second assay involving bioluminescence resonance energy transfer (BRET) technology. Moreover, two additional assays evaluating mutant protein degradation also were employed, one based on the disappearance of luminescence and another employing the ALPHA immunoassay. Imaging of cells revealed the cellular localization of mutant rhodopsin, whereas immunoblots identified changes in the aggregation and glycosylation of P23H mutant opsin. CONCLUSIONS Our findings indicate that these initial HTS and following assays can identify active therapeutic compounds, even for difficult targets such as mutant rhodopsin. The assays are readily scalable and their function has been proven with model compounds. High-throughput screening, supported by automated imaging and classic immunoassays, can further characterize multiple steps and pathways in the biosynthesis and degradation of this essential visual system protein.
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Affiliation(s)
- Yuanyuan Chen
- Department of Pharmacology Case Western Reserve University, Cleveland, Ohio, United States
| | - Hong Tang
- Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - William Seibel
- Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Ruben Papoian
- Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Xiaoyu Li
- Department of Pharmacology Case Western Reserve University, Cleveland, Ohio, United States
| | - Nevin A Lambert
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, Georgia, United States
| | - Krzysztof Palczewski
- Department of Pharmacology Case Western Reserve University, Cleveland, Ohio, United States
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Cioffi CL, Racz B, Freeman EE, Conlon MP, Chen P, Stafford DG, Schwarz DMC, Zhu L, Kitchen DB, Barnes KD, Dobri N, Michelotti E, Cywin CL, Martin WH, Pearson PG, Johnson G, Petrukhin K. Bicyclic [3.3.0]-Octahydrocyclopenta[c]pyrrolo Antagonists of Retinol Binding Protein 4: Potential Treatment of Atrophic Age-Related Macular Degeneration and Stargardt Disease. J Med Chem 2015; 58:5863-88. [PMID: 26181715 DOI: 10.1021/acs.jmedchem.5b00423] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Antagonists of retinol-binding protein 4 (RBP4) impede ocular uptake of serum all-trans retinol (1) and have been shown to reduce cytotoxic bisretinoid formation in the retinal pigment epithelium (RPE), which is associated with the pathogenesis of both dry age-related macular degeneration (AMD) and Stargardt disease. Thus, these agents show promise as a potential pharmacotherapy by which to stem further neurodegeneration and concomitant vision loss associated with geographic atrophy of the macula. We previously disclosed the discovery of a novel series of nonretinoid RBP4 antagonists, represented by bicyclic [3.3.0]-octahydrocyclopenta[c]pyrrolo analogue 4. We describe herein the utilization of a pyrimidine-4-carboxylic acid fragment as a suitable isostere for the anthranilic acid appendage of 4, which led to the discovery of standout antagonist 33. Analogue 33 possesses exquisite in vitro RBP4 binding affinity and favorable drug-like characteristics and was found to reduce circulating plasma RBP4 levels in vivo in a robust manner (>90%).
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Affiliation(s)
| | - Boglarka Racz
- §Department of Ophthalmology, Columbia University Medical Center, New York, New York 10032, United States
| | | | | | | | | | | | | | | | | | - Nicoleta Dobri
- §Department of Ophthalmology, Columbia University Medical Center, New York, New York 10032, United States
| | - Enrique Michelotti
- #National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Charles L Cywin
- ○National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - William H Martin
- ⊥WHM Consulting LLC, 111 Sterling City Road, Lyme, Connecticut 06371, United States
| | - Paul G Pearson
- ∥iCuraVision LLC, 31194 La Baya Drive, Suite 101, Westlake Village, California 91362, United States
| | - Graham Johnson
- ∥iCuraVision LLC, 31194 La Baya Drive, Suite 101, Westlake Village, California 91362, United States
| | - Konstantin Petrukhin
- §Department of Ophthalmology, Columbia University Medical Center, New York, New York 10032, United States
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Zhang J, Kiser PD, Badiee M, Palczewska G, Dong Z, Golczak M, Tochtrop GP, Palczewski K. Molecular pharmacodynamics of emixustat in protection against retinal degeneration. J Clin Invest 2015; 125:2781-94. [PMID: 26075817 DOI: 10.1172/jci80950] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/12/2015] [Indexed: 01/24/2023] Open
Abstract
Emixustat is a visual cycle modulator that has entered clinical trials as a treatment for age-related macular degeneration (AMD). This molecule has been proposed to inhibit the visual cycle isomerase RPE65, thereby slowing regeneration of 11-cis-retinal and reducing production of retinaldehyde condensation byproducts that may be involved in AMD pathology. Previously, we reported that all-trans-retinal (atRAL) is directly cytotoxic and that certain primary amine compounds that transiently sequester atRAL via Schiff base formation ameliorate retinal degeneration. Here, we have shown that emixustat stereoselectively inhibits RPE65 by direct active site binding. However, we detected the presence of emixustat-atRAL Schiff base conjugates, indicating that emixustat also acts as a retinal scavenger, which may contribute to its therapeutic effects. Using agents that lack either RPE65 inhibitory activity or the capacity to sequester atRAL, we assessed the relative importance of these 2 modes of action in protection against retinal phototoxicity in mice. The atRAL sequestrant QEA-B-001-NH2 conferred protection against phototoxicity without inhibiting RPE65, whereas an emixustat derivative incapable of atRAL sequestration was minimally protective, despite direct inhibition of RPE65. These data indicate that atRAL sequestration is an essential mechanism underlying the protective effects of emixustat and related compounds against retinal phototoxicity. Moreover, atRAL sequestration should be considered in the design of next-generation visual cycle modulators.
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50
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Jacobson SG, Cideciyan AV, Aguirre GD, Roman AJ, Sumaroka A, Hauswirth WW, Palczewski K. Improvement in vision: a new goal for treatment of hereditary retinal degenerations. Expert Opin Orphan Drugs 2015; 3:563-575. [PMID: 26246977 PMCID: PMC4487613 DOI: 10.1517/21678707.2015.1030393] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Introduction: Inherited retinal degenerations (IRDs) have long been considered untreatable and incurable. Recently, one form of early-onset autosomal recessive IRD, Leber congenital amaurosis (LCA) caused by mutations in RPE65 (retinal pigment epithelium-specific protein 65 kDa) gene, has responded with some improvement of vision to gene augmentation therapy and oral retinoid administration. This early success now requires refinement of such therapeutics to fully realize the impact of these major scientific and clinical advances. Areas covered: Progress toward human therapy for RPE65-LCA is detailed from the understanding of molecular mechanisms to preclinical proof-of-concept research to clinical trials. Unexpected positive and complicating results in the patients receiving treatment are explained. Logical next steps to advance the clinical value of the therapeutics are suggested. Expert opinion: The first molecularly based early-phase therapies for an IRD are remarkably successful in that vision has improved and adverse events are mainly associated with surgical delivery to the subretinal space. Yet, there are features of the gene augmentation therapeutic response, such as slowed kinetics of night vision, lack of foveal cone function improvement and relentlessly progressive retinal degeneration despite therapy, that still require research attention.
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Affiliation(s)
- Samuel G Jacobson
- University of Pennsylvania, Scheie Eye Institute, Perelman School of Medicine, Department of Ophthalmology , Philadelphia, PA, USA
| | - Artur V Cideciyan
- University of Pennsylvania, Scheie Eye Institute, Perelman School of Medicine, Department of Ophthalmology , Philadelphia, PA, USA
| | - Gustavo D Aguirre
- University of Pennsylvania, School of Veterinary Medicine, Section of Ophthalmology , Philadelphia, PA, USA
| | - Alejandro J Roman
- University of Pennsylvania, Scheie Eye Institute, Perelman School of Medicine, Department of Ophthalmology , Philadelphia, PA, USA
| | - Alexander Sumaroka
- University of Pennsylvania, Scheie Eye Institute, Perelman School of Medicine, Department of Ophthalmology , Philadelphia, PA, USA
| | | | - Krzysztof Palczewski
- Case Western University, School of Medicine, Cleveland Center for Membrane and Structural Biology, Department of Pharmacology , Cleveland, OH, USA
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