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Xiao K, Chen R, Lin R, Hu W, Liu J, Yusufu M, Huang Y, Li L. Association between micronutrients and myopia in American adolescents: evidence from the 2003-2006 National Health and Nutrition Examination Survey. Front Nutr 2024; 11:1477403. [PMID: 39421610 PMCID: PMC11484098 DOI: 10.3389/fnut.2024.1477403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2024] [Accepted: 09/17/2024] [Indexed: 10/19/2024] Open
Abstract
Purpose To investigate the associations between circulating micronutrients (vitamins A, C, D, E, and carotenoids) and the risk of myopia. Methods A total of 1,620 adolescents from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were included. Logistic regression was used to analyze the associations of micronutrients with myopia and high myopia. Restricted cubic spline analysis was employed to assess the potential nonlinear relationships. Results Among the 1,620 adolescents, 549 were diagnosed with myopia. After adjusting for multiple covariates, only cis-β-carotene was significantly associated with the risk of myopia (OR 1.19, 95% CI 1.03-1.39) and high myopia (OR 1.44, 95% CI 1.03-2.03). No significant associations were found between vitamins A, D, E, C, α-carotene, trans-β-carotene, lutein zeaxanthin, and myopia. No nonlinear relationships were observed between any of the micronutrients and myopia. Conclusion Cis-β-carotene is significantly associated with an increased risk of myopia and high myopia. Further research is needed to understand the underlying mechanisms and potential impact of cis-β-carotene on ocular health.
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Affiliation(s)
- Kunhong Xiao
- Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, Fuzhou, China
- Department of Ophthalmology and Optometry, Fujian Medical University, Fuzhou, China
| | - Ruiye Chen
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, VIC, Australia
| | - Rong Lin
- Department of Ophthalmology, West China Xiamen Hospital of Sichuan University, Xiamen, China
| | - Wenyi Hu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, VIC, Australia
| | - Jiahao Liu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, VIC, Australia
| | - Mayinuer Yusufu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, VIC, Australia
| | - Yan Huang
- Department of Ophthalmology and Optometry, Fujian Medical University, Fuzhou, China
| | - Li Li
- Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, Fuzhou, China
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Ghenciu LA, Hațegan OA, Stoicescu ER, Iacob R, Șișu AM. Emerging Therapeutic Approaches and Genetic Insights in Stargardt Disease: A Comprehensive Review. Int J Mol Sci 2024; 25:8859. [PMID: 39201545 PMCID: PMC11354485 DOI: 10.3390/ijms25168859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2024] [Revised: 08/09/2024] [Accepted: 08/12/2024] [Indexed: 09/02/2024] Open
Abstract
Stargardt disease, one of the most common forms of inherited retinal diseases, affects individuals worldwide. The primary cause is mutations in the ABCA4 gene, leading to the accumulation of toxic byproducts in the retinal pigment epithelium (RPE) and subsequent photoreceptor cell degeneration. Over the past few years, research on Stargardt disease has advanced significantly, focusing on clinical and molecular genetics. Recent studies have explored various innovative therapeutic approaches, including gene therapy, stem cell therapy, and pharmacological interventions. Gene therapy has shown promise, particularly with adeno-associated viral (AAV) vectors capable of delivering the ABCA4 gene to retinal cells. However, challenges remain due to the gene's large size. Stem cell therapy aims to replace degenerated RPE and photoreceptor cells, with several clinical trials demonstrating safety and preliminary efficacy. Pharmacological approaches focus on reducing toxic byproduct accumulation and modulating the visual cycle. Precision medicine, targeting specific genetic mutations and pathways, is becoming increasingly important. Novel techniques such as clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 offer potential for directly correcting genetic defects. This review aims to synthesize recent advancements in understanding and treating Stargardt disease. By highlighting breakthroughs in genetic therapies, stem cell treatments, and novel pharmacological strategies, it provides a comprehensive overview of emerging therapeutic options.
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Affiliation(s)
- Laura Andreea Ghenciu
- Department of Functional Sciences, “Victor Babeș” University of Medicine and Pharmacy Timișoara, Eftimie Murgu Square No. 2, 300041 Timișoara, Romania;
| | - Ovidiu Alin Hațegan
- Discipline of Anatomy and Embriology, Medicine Faculty, Vasile Goldis Western University of Arad, Revolution Boulevard 94, 310025 Arad, Romania
| | - Emil Robert Stoicescu
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timișoara, Mihai Viteazul Boulevard No. 1, 300222 Timișoara, Romania; (E.R.S.); (R.I.)
- Department of Radiology and Medical Imaging, ‘Victor Babeș’ University of Medicine and Pharmacy Timișoara, Eftimie Murgu Square No. 2, 300041 Timișoara, Romania
- Research Center for Pharmaco-Toxicological Evaluations, ‘Victor Babeș’ University of Medicine and Pharmacy Timișoara, Eftimie Murgu Square No. 2, 300041 Timișoara, Romania
| | - Roxana Iacob
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timișoara, Mihai Viteazul Boulevard No. 1, 300222 Timișoara, Romania; (E.R.S.); (R.I.)
- Department of Anatomy and Embriology, ‘Victor Babeș’ University of Medicine and Pharmacy Timișoara, 300041 Timișoara, Romania;
| | - Alina Maria Șișu
- Department of Anatomy and Embriology, ‘Victor Babeș’ University of Medicine and Pharmacy Timișoara, 300041 Timișoara, Romania;
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Ng ESY, Hu J, Jiang Z, Radu RA. Impaired cathepsin D in retinal pigment epithelium cells mediates Stargardt disease pathogenesis. FASEB J 2024; 38:e23720. [PMID: 38837708 PMCID: PMC11296957 DOI: 10.1096/fj.202400210rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 05/12/2024] [Accepted: 05/21/2024] [Indexed: 06/07/2024]
Abstract
Recessive Stargardt disease (STGD1) is an inherited juvenile maculopathy caused by mutations in the ABCA4 gene, for which there is no suitable treatment. Loss of functional ABCA4 in the retinal pigment epithelium (RPE) alone, without contribution from photoreceptor cells, was shown to induce STGD1 pathology. Here, we identified cathepsin D (CatD), the primary RPE lysosomal protease, as a key molecular player contributing to endo-lysosomal dysfunction in STGD1 using a newly developed "disease-in-a-dish" RPE model from confirmed STGD1 patients. Induced pluripotent stem cell (iPSC)-derived RPE originating from three STGD1 patients exhibited elevated lysosomal pH, as previously reported in Abca4-/- mice. CatD protein maturation and activity were impaired in RPE from STGD1 patients and Abca4-/- mice. Consequently, STGD1 RPE cells have reduced photoreceptor outer segment degradation and abnormal accumulation of α-synuclein, the natural substrate of CatD. Furthermore, dysfunctional ABCA4 in STGD1 RPE cells results in intracellular accumulation of autofluorescent material and phosphatidylethanolamine (PE). The altered distribution of PE associated with the internal membranes of STGD1 RPE cells presumably compromises LC3-associated phagocytosis, contributing to delayed endo-lysosomal degradation activity. Drug-mediated re-acidification of lysosomes in the RPE of STGD1 restores CatD functional activity and reduces the accumulation of immature CatD protein loads. This preclinical study validates the contribution of CatD deficiencies to STGD1 pathology and provides evidence for an efficacious therapeutic approach targeting RPE cells. Our findings support a cell-autonomous RPE-driven pathology, informing future research aimed at targeting RPE cells to treat ABCA4-mediated retinopathies.
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Affiliation(s)
- Eunice Sze Yin Ng
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Molecular, Cellular, and Integrative Physiology Interdepartmental Program, University of California, Los Angeles, CA 90095, USA
| | - Jane Hu
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Zhichun Jiang
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Roxana A. Radu
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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Różanowska MB. Lipofuscin, Its Origin, Properties, and Contribution to Retinal Fluorescence as a Potential Biomarker of Oxidative Damage to the Retina. Antioxidants (Basel) 2023; 12:2111. [PMID: 38136230 PMCID: PMC10740933 DOI: 10.3390/antiox12122111] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Lipofuscin accumulates with age as intracellular fluorescent granules originating from incomplete lysosomal digestion of phagocytosed and autophagocytosed material. The purpose of this review is to provide an update on the current understanding of the role of oxidative stress and/or lysosomal dysfunction in lipofuscin accumulation and its consequences, particularly for retinal pigment epithelium (RPE). Next, the fluorescence of lipofuscin, spectral changes induced by oxidation, and its contribution to retinal fluorescence are discussed. This is followed by reviewing recent developments in fluorescence imaging of the retina and the current evidence on the prognostic value of retinal fluorescence for the progression of age-related macular degeneration (AMD), the major blinding disease affecting elderly people in developed countries. The evidence of lipofuscin oxidation in vivo and the evidence of increased oxidative damage in AMD retina ex vivo lead to the conclusion that imaging of spectral characteristics of lipofuscin fluorescence may serve as a useful biomarker of oxidative damage, which can be helpful in assessing the efficacy of potential antioxidant therapies in retinal degenerations associated with accumulation of lipofuscin and increased oxidative stress. Finally, amendments to currently used fluorescence imaging instruments are suggested to be more sensitive and specific for imaging spectral characteristics of lipofuscin fluorescence.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, College of Biomedical and Life Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, Wales, UK;
- Cardiff Institute for Tissue Engineering and Repair (CITER), Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK
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Mizobuchi K, Hayashi T, Ueno S, Kondo M, Terasaki H, Aoki T, Nakano T. One-Year Outcomes of Oral Treatment With Alga Capsules Containing Low Levels of 9-cis-β-Carotene in RDH5-Related Fundus Albipunctatus. Am J Ophthalmol 2023; 254:193-202. [PMID: 37343743 DOI: 10.1016/j.ajo.2023.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 06/13/2023] [Accepted: 06/13/2023] [Indexed: 06/23/2023]
Abstract
PURPOSE This study aimed to clarify the effect of 1-year oral treatment with 9-cis-β-carotene-rich alga Dunaliella bardawil (Dunaliella supplementation) using full-field electroretinography (ERG) in patients with RDH5-related fundus albipunctatus (FAP). DESIGN Prospective, interventional case series. PARTICIPANTS The study included 12 patients (23 eyes) with RDH5-related FAP. METHODS Twelve patients (23 eyes) with RDH5-related FAP received Dunaliella supplementation (total daily dose of β-carotene was 74.0 mg, comprising 28.4 mg 9-cis-β-carotene and 45.6 mg all-trans-β-carotene at a ratio of 1:1.6) for 1 year and underwent ophthalmic examinations, including full-field ERG at baseline, 3 months, and 1 year after the initial treatment. MAIN OUTCOME MEASURES The main outcome was changes in the amplitudes of responses of full-field ERG before and after treatment. A linear mixed-effects model was used to evaluate the adjusted mean difference between the amplitude of each response pretreatment and posttreatment. RESULTS Prolonged dark adaptation (DA) responses at 3 months revealed a significant impairment in the b-wave of DA 0.01 (adjusted mean difference, -34.7, 95% CI, -66.8 to -2.73, P = .041) and a-wave of DA 3.0 (-29.0, 95% CI, -50.6 to -7.41, P = .013) and DA 10.0 (-40.4, 95% CI, -67.8 to -13.0, P = .007), which were also observed at 1 year. Additionally, prolonged DA and light adaptation (LA) responses revealed statistically significant impairment at 1 year in the b-wave of DA 3.0 (-43.8, 95% CI, -82.9 to -4.78, P = .035), DA 10.0 (-59.7, 95% CI, -101.8 to -17.61, P = .009), LA 3.0 (-7.31, 95% CI, -13.6 to -1.04, P = .029), and LA 3.0 flicker (-7.53, 95% CI, -12.7 to -2.34, P = .007). CONCLUSIONS Our study results suggest that Dunaliella supplementation comprising low levels of 9-cis-β-carotene compared with those reported in a previous study (1:1 ratio) adversely affects ERG amplitudes in patients with RDH5-related FAP.
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Affiliation(s)
- Kei Mizobuchi
- From the Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan (K.M., T.H., T.N.)
| | - Takaaki Hayashi
- From the Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan (K.M., T.H., T.N.); Department of Ophthalmology, Katsushika Medical Center, The Jikei University School of Medicine, Tokyo, Japan (T.H.).
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan (S.U., H.T.); Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Aomori, Japan (S.U.)
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Mie, Japan (M.K.)
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan (S.U., H.T.)
| | - Takuya Aoki
- Division of Clinical Epidemiology, Research Center for Medical Sciences, The Jikei University School of Medicine, Tokyo, Japan (T.A.)
| | - Tadashi Nakano
- From the Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan (K.M., T.H., T.N.)
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Wang L, Shah SM, Mangwani-Mordani S, Gregori NZ. Updates on Emerging Interventions for Autosomal Recessive ABCA4-Associated Stargardt Disease. J Clin Med 2023; 12:6229. [PMID: 37834872 PMCID: PMC10573680 DOI: 10.3390/jcm12196229] [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: 09/08/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
Autosomal recessive Stargardt disease (STGD1) is an inherited retinal degenerative disease associated with a mutated ATP-binding cassette, subfamily A, member 4 (ABCA4) gene. STGD1 is the most common form of juvenile macular degeneration with onset in late childhood to early or middle adulthood and causes progressive, irreversible visual impairment and blindness. No effective treatment is currently available. In the present article, we review the most recent updates in clinical trials targeting the management of STGD1, including gene therapy, small molecule therapy, and stem cell therapy. In gene therapy, dual adeno-associated virus and non-viral vectors have been successful in delivering the human ABCA4 gene in preclinical studies. For pharmaceutical therapies ALK-001, deuterated vitamin A shows promise with preliminary data for phase 2 trial, demonstrating a decreased atrophy growth rate after two years. Stem cell therapy using human pluripotent stem cell-derived retinal pigment epithelium cells demonstrated long-term safety three years after implantation and visual acuity improvements in the first two years after initiation of therapy. Many other treatment options have ongoing investigations and clinical trials. While multiple potential interventions have shown promise in attenuating disease progression, further exploration is necessary to demonstrate treatment safety and efficacy.
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Affiliation(s)
- Liang Wang
- University of Miami Miller School of Medicine, Miami, FL 33136, USA; (L.W.); (S.M.S.)
| | - Serena M. Shah
- University of Miami Miller School of Medicine, Miami, FL 33136, USA; (L.W.); (S.M.S.)
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Simran Mangwani-Mordani
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Ninel Z. Gregori
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- Miami Veterans Administration Medical Center, Miami, FL 33125, USA
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7
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Kim HJ, Zhao J, Walewski JL, Sparrow JR. A High Fat Diet Fosters Elevated Bisretinoids. J Biol Chem 2023; 299:104784. [PMID: 37146972 DOI: 10.1016/j.jbc.2023.104784] [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: 01/26/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/07/2023] Open
Abstract
High dietary fat intake is associated with metabolic dysregulation, but little is known regarding the effects of a high fat diet (HFD) on photoreceptor cell functioning. We explored the intersection of a high fat diet (HFD) and the visual cycle adducts that form in photoreceptor cells by non-enzymatic reactions. In black C57BL/6J mice and albino C57BL/6Jc2j mice raised on a high fat diet until age 3, 6 or 12 months, chromatographically quantified bisretinoids were increased relative to mice on a standard diet. In vivo measurement of fundus autofluorescence, the source of which is bisretinoid, also revealed a significant increase in the HFD-mice. Additionally, mice provided with a diet high in fat presented with elevated retinol-binding protein 4 (RBP4) the protein responsible for transporting retinol in plasma. Vitamin A was elevated in plasma although not in ocular tissue. Bisretinoids form in photoreceptor cell outer segments by random reactions of retinaldehyde with phosphatidylethanolamine. We found that the latter phospholipid was significantly increased in mice fed a HFD versus mice on a control diet. In leptin-deficient ob/ob mice, a genetic model of obesity, plasma levels of Rbp4 protein were higher but bisretinoids in retina were not elevated. Photoreceptor cell viability measured as outer nuclear layer thickness was reduced in the ob/ob mice relative to wild-type. The accelerated formation of bisretinoid we observed in diet induced obese mice is related to the high fat intake and to increased delivery of vitamin A to the visual cycle.
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Affiliation(s)
- Hye Jin Kim
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Jin Zhao
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Jose L Walewski
- Departments of Medicine, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Janet R Sparrow
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032; Departments of Pathology and Cell Biology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032.
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Nguyen XTA, Moekotte L, Plomp AS, Bergen AA, van Genderen MM, Boon CJF. Retinitis Pigmentosa: Current Clinical Management and Emerging Therapies. Int J Mol Sci 2023; 24:ijms24087481. [PMID: 37108642 PMCID: PMC10139437 DOI: 10.3390/ijms24087481] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/01/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Retinitis pigmentosa (RP) comprises a group of inherited retinal dystrophies characterized by the degeneration of rod photoreceptors, followed by the degeneration of cone photoreceptors. As a result of photoreceptor degeneration, affected individuals experience gradual loss of visual function, with primary symptoms of progressive nyctalopia, constricted visual fields and, ultimately, central vision loss. The onset, severity and clinical course of RP shows great variability and unpredictability, with most patients already experiencing some degree of visual disability in childhood. While RP is currently untreatable for the majority of patients, significant efforts have been made in the development of genetic therapies, which offer new hope for treatment for patients affected by inherited retinal dystrophies. In this exciting era of emerging gene therapies, it remains imperative to continue supporting patients with RP using all available options to manage their condition. Patients with RP experience a wide variety of physical, mental and social-emotional difficulties during their lifetime, of which some require timely intervention. This review aims to familiarize readers with clinical management options that are currently available for patients with RP.
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Affiliation(s)
- Xuan-Thanh-An Nguyen
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Lude Moekotte
- Department of Ophthalmology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Astrid S Plomp
- Department of Clinical Genetics, Amsterdam University Medical Centers, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Arthur A Bergen
- Department of Clinical Genetics, Amsterdam University Medical Centers, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Maria M van Genderen
- Department of Ophthalmology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
- Bartiméus, Diagnostic Center for Complex Visual Disorders, 3703 AJ Zeist, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam University Medical Centers, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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9
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Strauss RW, Ho A, Jha A, Fujinami K, Michaelides M, Cideciyan AV, Audo I, Birch DG, Sadda S, Ip M, West S, Schönbach EM, Kong X, Scholl HPN. Progression of Stargardt Disease as Determined by Fundus Autofluorescence Over a 24-Month Period (ProgStar Report No. 17). Am J Ophthalmol 2023; 250:157-170. [PMID: 36764427 DOI: 10.1016/j.ajo.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/19/2022] [Accepted: 02/02/2023] [Indexed: 02/11/2023]
Abstract
PURPOSE To estimate the progression rate of atrophic lesions in Stargardt disease derived from fundus autofluorescence (FAF). DESIGN International, multicenter, prospective cohort study. METHODS A total of 259 participants aged ≥6 years with disease-causing variants in the ABCA4 gene were enrolled from 9 centers and followed over a 24-month period. FAF images were obtained every 6 months, and areas of definitely decreased autofluorescence (DDAF) and decreased autofluorescence (DAF) were quantified. Progression rates were estimated from linear mixed models with time as the independent variable. RESULTS A total of 488 study eyes of 259 participants (88.8% with both eyes) were enrolled and images from 432 eyes were followed for 24 months. The overall estimated progression of DDAF was 0.74 mm2/y (95% CI 0.64-0.85, P < .0001) and that of DAF was 0.64 mm2/y (95% CI 0.57-0.71) over a 24-month period in univariate analysis. Growth rates were strongly dependent on baseline lesion area. After square root transformation, the DDAF growth rate was not dependent on baseline lesion radius (P = .11), whereas the DAF growth rate was dependent (P < .0001). Genotype was not found to significantly impact the growth rate of DDAF or DAF lesions. CONCLUSIONS FAF may serve as a convenient monitoring tool and suitable end point for interventional clinical trials that aim to slow disease progression. DDAF and DAF lesion sizes at baseline are strong predicting factors for lesion area growth and can be partially accounted for by square root transformation.
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Affiliation(s)
- Rupert W Strauss
- From the Department of Ophthalmology, Medical University Graz (R.W.S.), Graz, Austria; Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, University College London (R.W.S., K.F., M.M.), London, United Kingdom; Department of Ophthalmology, Kepler University Clinic (R.W.S.), Linz, Austria; Institute of Clinical and Molecular Ophthalmology Basel (IOB) (R.W.S., H.P.N.S.), Basel, Switzerland
| | - Alexander Ho
- Doheny Eye Institute, David Geffen School of Medicine at University of California Los Angeles (A.H., A.J., S.S., M.I.), California, USA
| | - Anamika Jha
- Doheny Eye Institute, David Geffen School of Medicine at University of California Los Angeles (A.H., A.J., S.S., M.I.), California, USA
| | - Kaoru Fujinami
- Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, University College London (R.W.S., K.F., M.M.), London, United Kingdom; Laboratory of Visual Physiology, Division for Vision Research, National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Center (K.F.), Tokyo, Japan
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, University College London (R.W.S., K.F., M.M.), London, United Kingdom
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania (A.V.C.), Philadelphia, Pennsylvania, USA
| | - Isabelle Audo
- Sorbonne Universités, University Pierre et Marie Curie (UPMC) Université de Paris 06, Institut national de la santé et de la recherche médicale (INSERM), Centre national de la recherche scientifique (CNRS), Institut de la Vision, Centre Hospitalier National d'Ophtalmologie (CHNO) des Quinze-Vingts (I.A.), Paris, France
| | - David G Birch
- Retina Foundation of the Southwest, Dallas (D.G.B.), Texas, USA
| | - Srinivas Sadda
- Doheny Eye Institute, David Geffen School of Medicine at University of California Los Angeles (A.H., A.J., S.S., M.I.), California, USA
| | - Michael Ip
- Doheny Eye Institute, David Geffen School of Medicine at University of California Los Angeles (A.H., A.J., S.S., M.I.), California, USA
| | - Sheila West
- Wilmer Eye Institute, Johns Hopkins University (S.W., X.K.), Baltimore, USA
| | - Etienne M Schönbach
- Shiley Eye Institute and Jacobs Retina Center, University of California, San Diego (E.M.S.), La Jolla, California, USA
| | - Xiangrong Kong
- Wilmer Eye Institute, Johns Hopkins University (S.W., X.K.), Baltimore, USA
| | - Hendrik P N Scholl
- Institute of Clinical and Molecular Ophthalmology Basel (IOB) (R.W.S., H.P.N.S.), Basel, Switzerland; Department of Ophthalmology, University of Basel (H.P.N.S.), Basel, Switzerland.
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Ng ESY, Kady N, Hu J, Dave A, Jiang Z, Pei J, Gorin MB, Matynia A, Radu RA. Membrane Attack Complex Mediates Retinal Pigment Epithelium Cell Death in Stargardt Macular Degeneration. Cells 2022; 11:3462. [PMID: 36359858 PMCID: PMC9655712 DOI: 10.3390/cells11213462] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 10/28/2022] [Accepted: 10/30/2022] [Indexed: 08/22/2023] Open
Abstract
Recessive Stargardt disease (STGD1) is an inherited retinopathy caused by mutations in the ABCA4 gene. The ABCA4 protein is a phospholipid-retinoid flippase in the outer segments of photoreceptors and the internal membranes of retinal pigment epithelial (RPE) cells. Here, we show that RPE cells derived via induced pluripotent stem-cell from a molecularly and clinically diagnosed STGD1 patient exhibited reduced ABCA4 protein and diminished activity compared to a normal subject. Consequently, STGD1 RPE cells accumulated intracellular autofluorescence-lipofuscin and displayed increased complement C3 activity. The level of C3 inversely correlated with the level of CD46, an early negative regulator of the complement cascade. Persistent complement dysregulation led to deposition of the membrane attack complex on the surface of RPE cells, decrease in transepithelial resistance, and subsequent cell death. These findings are strong evidence of complement-mediated RPE cell damage in STGD1, in the absence of photoreceptors, caused by reduced CD46 regulatory protein.
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Affiliation(s)
- Eunice Sze Yin Ng
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
- Molecular Cellular and Integrative Physiology Interdepartmental Program, University of California, Los Angeles, CA 90095, USA
| | - Nermin Kady
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
- Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI 48109, USA
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Jane Hu
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
| | - Arpita Dave
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
| | - Zhichun Jiang
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
| | - Jacqueline Pei
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
| | - Michael B. Gorin
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
| | - Anna Matynia
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
| | - Roxana A. Radu
- UCLA Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, CA 90095, USA
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Tan LX, Li J, Germer CJ, Lakkaraju A. Analysis of mitochondrial dynamics and function in the retinal pigment epithelium by high-speed high-resolution live imaging. Front Cell Dev Biol 2022; 10:1044672. [PMID: 36393836 PMCID: PMC9651161 DOI: 10.3389/fcell.2022.1044672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial dysfunction is strongly implicated in neurodegenerative diseases including age-related macular degeneration (AMD), which causes irreversible blindness in over 50 million older adults worldwide. A key site of insult in AMD is the retinal pigment epithelium (RPE), a monolayer of postmitotic polarized cells that performs essential functions for photoreceptor health and vision. Recent studies from our group and others have identified several features of mitochondrial dysfunction in AMD including mitochondrial fragmentation and bioenergetic defects. While these studies provide valuable insight at fixed points in time, high-resolution, high-speed live imaging is essential for following mitochondrial injury in real time and identifying disease mechanisms. Here, we demonstrate the advantages of live imaging to investigate RPE mitochondrial dynamics in cell-based and mouse models. We show that mitochondria in the RPE form extensive networks that are destroyed by fixation and discuss important live imaging considerations that can interfere with accurate evaluation of mitochondrial integrity such as RPE differentiation status and acquisition parameters. Our data demonstrate that RPE mitochondria show localized heterogeneities in membrane potential and ATP production that could reflect focal changes in metabolism and oxidative stress. Contacts between the mitochondria and organelles such as the ER and lysosomes mediate calcium flux and mitochondrial fission. Live imaging of mouse RPE flatmounts revealed a striking loss of mitochondrial integrity in albino mouse RPE compared to pigmented mice that could have significant functional consequences for cellular metabolism. Our studies lay a framework to guide experimental design and selection of model systems for evaluating mitochondrial health and function in the RPE.
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Affiliation(s)
- Li Xuan Tan
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
| | - Jianlong Li
- Department of Cell and Tissue Biology, School of Dentistry, University of California, San Francisco, CA, United States
| | - Colin J. Germer
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, United States
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, United States
- Department of Anatomy, School of Medicine, University of California, San Francisco, CA, United States
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12
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The novel visual cycle inhibitor (±)-RPE65-61 protects retinal photoreceptors from light-induced degeneration. PLoS One 2022; 17:e0269437. [PMID: 36227868 PMCID: PMC9560169 DOI: 10.1371/journal.pone.0269437] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/23/2022] [Indexed: 11/25/2022] Open
Abstract
The visual cycle refers to a series of biochemical reactions of retinoids in ocular tissues and supports the vision in vertebrates. The visual cycle regenerates visual pigments chromophore, 11-cis-retinal, and eliminates its toxic byproducts from the retina, supporting visual function and retinal neuron survival. Unfortunately, during the visual cycle, when 11-cis-retinal is being regenerated in the retina, toxic byproducts, such as all-trans-retinal and bis-retinoid is N-retinylidene-N-retinylethanolamine (A2E), are produced, which are proposed to contribute to the pathogenesis of the dry form of age-related macular degeneration (AMD). The primary biochemical defect in Stargardt disease (STGD1) is the accelerated synthesis of cytotoxic lipofuscin bisretinoids, such as A2E, in the retinal pigment epithelium (RPE) due to mutations in the ABCA4 gene. To prevent all-trans-retinal-and bisretinoid-mediated retinal degeneration, slowing down the retinoid flow by modulating the visual cycle with a small molecule has been proposed as a therapeutic strategy. The present study describes RPE65-61, a novel, non-retinoid compound, as an inhibitor of RPE65 (a key enzyme in the visual cycle), intended to modulate the excessive activity of the visual cycle to protect the retina from harm degenerative diseases. Our data demonstrated that (±)-RPE65-61 selectively inhibited retinoid isomerase activity of RPE65, with an IC50 of 80 nM. Furthermore, (±)-RPE65-61 inhibited RPE65 via an uncompetitive mechanism. Systemic administration of (±)-RPE65-61 in mice resulted in slower chromophore regeneration after light bleach, confirming in vivo target engagement and visual cycle modulation. Concomitant protection of the mouse retina from high-intensity light damage was also observed. Furthermore, RPE65-61 down-regulated the cyclic GMP-AMP synthase stimulator of interferon genes (cGAS-STING) pathway, decreased the inflammatory factor, and attenuated retinal apoptosis caused by light-induced retinal damage (LIRD), which led to the preservation of the retinal function. Taken together, (±)-RPE65-61 is a potent visual cycle modulator that may provide a neuroprotective therapeutic benefit for patients with STGD and AMD.
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Cui X, Kim HJ, Cheng CH, Jenny LA, Lima de Carvalho JR, Chang YJ, Kong Y, Hsu CW, Huang IW, Ragi SD, Lin CS, Li X, Sparrow JR, Tsang SH. Long-term vitamin A supplementation in a preclinical mouse model for RhoD190N-associated retinitis pigmentosa. Hum Mol Genet 2022; 31:2438-2451. [PMID: 35195241 PMCID: PMC9307315 DOI: 10.1093/hmg/ddac032] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/10/2022] [Accepted: 01/25/2022] [Indexed: 01/12/2023] Open
Abstract
Retinitis pigmentosa (RP) is caused by one of many possible gene mutations. The National Institutes of Health recommends high daily doses of vitamin A palmitate for RP patients. There is a critical knowledge gap surrounding the therapeutic applicability of vitamin A to patients with the different subtypes of the disease. Here, we present a case report of a patient with RP caused by a p.D190N mutation in Rhodopsin (RHO) associated with abnormally high quantitative autofluorescence values after long-term vitamin A supplementation. We investigated the effects of vitamin A treatment strategy on RP caused by the p.D190N mutation in RHO by exposing Rhodopsin p.D190N (RhoD190N/+) and wild-type (WT) mice to experimental vitamin A-supplemented and standard control diets. The patient's case suggests that the vitamin A treatment strategy should be further studied to determine its effect on RP caused by p.D190N mutation in RHO and other mutations. Our mouse experiments revealed that RhoD190N/+ mice on the vitamin A diet exhibited higher levels of autofluorescence and lipofuscin metabolites compared to WT mice on the same diet and isogenic controls on the standard control diet. Vitamin A supplementation diminished photoreceptor function in RhoD190N/+ mice while preserving cone response in WT mice. Our findings highlight the importance of more investigations into the efficacy of clinical treatments like vitamin A for patients with certain genetic subtypes of disease and of genotyping in the precision care of inherited retinal degenerations.
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Affiliation(s)
- Xuan Cui
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
- School of Optometry and Ophthalmology, Tianjin Medical University Eye Institute, Tianjin Medical University Eye Hospital, Tianjin Medical University, Tianjin 300384, China
- Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA
| | - Hye Jin Kim
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Chia-Hua Cheng
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Laura A Jenny
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Jose Ronaldo Lima de Carvalho
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Ya-Ju Chang
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Yang Kong
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Chun-Wei Hsu
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - I-Wen Huang
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Sara D Ragi
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
| | - Chyuan-Sheng Lin
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Xiaorong Li
- School of Optometry and Ophthalmology, Tianjin Medical University Eye Institute, Tianjin Medical University Eye Hospital, Tianjin Medical University, Tianjin 300384, China
| | - Janet R Sparrow
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
- Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Stephen H Tsang
- Jonas Children’s Vision Care, and the Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY 10032, USA
- Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY 10032, USA
- Columbia Stem Cell Initiative, Columbia University, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
- Institute of Human Nutrition, Columbia University, New York, NY 10032, USA
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Thirunavukarasu AJ, Ross AC, Gilbert RM. Vitamin A, systemic T-cells, and the eye: Focus on degenerative retinal disease. Front Nutr 2022; 9:914457. [PMID: 35923205 PMCID: PMC9339908 DOI: 10.3389/fnut.2022.914457] [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: 04/06/2022] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
The first discovered vitamin, vitamin A, exists in a range of forms, primarily retinoids and provitamin carotenoids. The bioactive forms of vitamin A, retinol and retinoic acid, have many critical functions in body systems including the eye and immune system. Vitamin A deficiency is associated with dysfunctional immunity, and presents clinically as a characteristic ocular syndrome, xerophthalmia. The immune functions of vitamin A extend to the gut, where microbiome interactions and nutritional retinoids and carotenoids contribute to the balance of T cell differentiation, thereby determining immune status and contributing to inflammatory disease around the whole body. In the eye, degenerative conditions affecting the retina and uvea are influenced by vitamin A. Stargardt's disease (STGD1; MIM 248200) is characterised by bisretinoid deposits such as lipofuscin, produced by retinal photoreceptors as they use and recycle a vitamin A-derived chromophore. Age-related macular degeneration features comparable retinal deposits, such as drusen featuring lipofuscin accumulation; and is characterised by parainflammatory processes. We hypothesise that local parainflammatory processes secondary to lipofuscin deposition in the retina are mediated by T cells interacting with dietary vitamin A derivatives and the gut microbiome, and outline the current evidence for this. No cures exist for Stargardt's or age-related macular degeneration, but many vitamin A-based therapeutic approaches have been or are being trialled. The relationship between vitamin A's functions in systemic immunology and the eye could be further exploited, and further research may seek to leverage the interactions of the gut-eye immunological axis.
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Affiliation(s)
- Arun J. Thirunavukarasu
- Corpus Christi College, University of Cambridge, Cambridge, United Kingdom
- University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - A. Catharine Ross
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, United States
| | - Rose M. Gilbert
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
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15
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Mice Lacking the Systemic Vitamin A Receptor RBPR2 Show Decreased Ocular Retinoids and Loss of Visual Function. Nutrients 2022; 14:nu14122371. [PMID: 35745101 PMCID: PMC9231411 DOI: 10.3390/nu14122371] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/31/2022] [Accepted: 06/03/2022] [Indexed: 02/05/2023] Open
Abstract
Simple Summary This work represents an initial evaluation of the second RBP4-vitamin A receptor RBPR2 in a mammalian model. We provide evidence that the membrane localized RBPR2 protein, under variable conditions of dietary vitamin A intake, plays an important role for dietary vitamin A transport to the eye for ocular retinoid homeostasis and visual function. These findings are of general interest, as disturbances in blood and ocular vitamin A homeostasis are linked to retinal degenerative diseases, which are blinding diseases. The animal model described here could also serve as an in vivo tool to study mechanisms related to retinal cell degeneration that are associated with vitamin A deficiency. Abstract The systemic transport of dietary vitamin A/all-trans retinol bound to RBP4 into peripheral tissues for storage is an essential physiological process that continuously provides visual chromophore precursors to the retina under fasting conditions. This mechanism is critical for phototransduction, photoreceptor cell maintenance and survival, and in the support of visual function. While the membrane receptor STRA6 facilitates the blood transport of lipophilic vitamin A into the eye, it is not expressed in most peripheral organs, which are proposed to express a second membrane receptor for the uptake of vitamin A from circulating RBP4. The discovery of a novel vitamin A receptor, RBPR2, which is expressed in the liver and intestine, but not in the eye, alluded to this long-sort non-ocular membrane receptor for systemic RBP4-ROL uptake and transport. We have previously shown in zebrafish that the retinol-binding protein receptor 2 (Rbpr2) plays an important role in the transport of yolk vitamin A to the eye. Mutant rbpr2 zebrafish lines manifested in decreased ocular retinoid concentrations and retinal phenotypes. To investigate a physiological role for the second vitamin A receptor, RBPR2, in mammals and to analyze the metabolic basis of systemic vitamin A transport for retinoid homeostasis, we established a whole-body Rbpr2 knockout mouse (Rbpr2−/−) model. These mice were viable on both vitamin A-sufficient and -deficient diets. Rbpr2−/− mice that were fed a vitamin A-sufficient diet displayed lower ocular retinoid levels, decreased opsins, and manifested in decrease visual function, as measured by electroretinography. Interestingly, when Rbpr2−/− mice were fed a vitamin A-deficient diet, they additionally showed shorter photoreceptor outer segment phenotypes, altogether manifesting in a significant loss of visual function. Thus, under conditions replicating vitamin A sufficiency and deficiency, our analyses revealed that RBPR2-mediated systemic vitamin A transport is a regulated process that is important for vitamin A delivery to the eye when RBP4-bound ROL is the only transport pathway in the fasting condition or under vitamin A deficiency conditions.
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16
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Alsberge JB, Agarwal A. Late-onset Stargardt disease. Am J Ophthalmol Case Rep 2022; 26:101429. [PMID: 35243166 PMCID: PMC8866146 DOI: 10.1016/j.ajoc.2022.101429] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 02/09/2022] [Accepted: 02/14/2022] [Indexed: 11/26/2022] Open
Abstract
Purpose To report a case of late-onset Stargardt disease, discuss the differential diagnosis, and review the role of vitamin A supplementation in Stargardt disease. Observations A 60-year-old man presented with blurry vision in the right eye for the past two years. Current medications included a daily multivitamin containing vitamin A and age-related eye disease study vitamins. Examination revealed bilateral macular atrophy and scattered yellow flecks which were intensely hyperautofluorescent. Fluorescein angiography revealed a dark choroid. Full-field electroretinogram showed normal rod and cone responses, and genetic testing revealed two pathogenic ABCA4 gene variations confirming the diagnosis of late-onset Stargardt disease. Conclusions Stargardt disease is typically described in young patients but may develop later in adulthood and masquerade as age-related macular degeneration and a number of other conditions. Though the evidence is limited, there is concern that high-dose vitamin A supplementation could lead to progression of Stargardt disease. Avoidance of high-dose vitamin A supplementation should be discussed with Stargardt disease patients.
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17
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Moran AL, Carter SP, Kaylor JJ, Jiang Z, Broekman S, Dillon ET, Gómez Sánchez A, Minhas SK, van Wijk E, Radu RA, Travis GH, Carey M, Blacque OE, Kennedy BN. Dawn and dusk peaks of outer segment phagocytosis, and visual cycle function require Rab28. FASEB J 2022; 36:e22309. [PMID: 35471581 PMCID: PMC9322422 DOI: 10.1096/fj.202101897r] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/14/2022] [Accepted: 03/29/2022] [Indexed: 12/12/2022]
Abstract
RAB28 is a farnesylated, ciliary G-protein. Patient variants in RAB28 are causative of autosomal recessive cone-rod dystrophy (CRD), an inherited human blindness. In rodent and zebrafish models, the absence of Rab28 results in diminished dawn, photoreceptor, outer segment phagocytosis (OSP). Here, we demonstrate that Rab28 is also required for dusk peaks of OSP, but not for basal OSP levels. This study further elucidated the molecular mechanisms by which Rab28 controls OSP and inherited blindness. Proteomic profiling identified factors whose expression in the eye or whose expression at dawn and dusk peaks of OSP is dysregulated by loss of Rab28. Notably, transgenic overexpression of Rab28, solely in zebrafish cones, rescues the OSP defect in rab28 KO fish, suggesting rab28 gene replacement in cone photoreceptors is sufficient to regulate Rab28-OSP. Rab28 loss also perturbs function of the visual cycle as retinoid levels of 11-cRAL, 11cRP, and atRP are significantly reduced in larval and adult rab28 KO retinae (p < .05). These data give further understanding on the molecular mechanisms of RAB28-associated CRD, highlighting roles of Rab28 in both peaks of OSP, in vitamin A metabolism and in retinoid recycling.
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Affiliation(s)
- Ailís L. Moran
- UCD School of Biomolecular and Biomedical ScienceUniversity College DublinDublinIreland
- UCD Conway InstituteUniversity College DublinDublinIreland
| | - Stephen P. Carter
- UCD School of Biomolecular and Biomedical ScienceUniversity College DublinDublinIreland
- UCD Conway InstituteUniversity College DublinDublinIreland
| | - Joanna J. Kaylor
- Department of OphthalmologyDavid Geffen School of MedicineUCLA Stein Eye InstituteUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | - Zhichun Jiang
- Department of OphthalmologyDavid Geffen School of MedicineUCLA Stein Eye InstituteUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | - Sanne Broekman
- Department of OtorhinolaryngologyRadboud University Medical CenterNijmegenThe Netherlands
- Donders Institute for Brain, Cognition, and BehaviorNijmegenThe Netherlands
| | | | - Alicia Gómez Sánchez
- UCD Conway InstituteUniversity College DublinDublinIreland
- Ocupharm Diagnostic Group ResearchFaculty of Optic and OptometryUniversidad Complutense de MadridMadridSpain
| | - Sajal K. Minhas
- UCD School of Mathematics & StatisticsUniversity College DublinDublinIreland
| | - Erwin van Wijk
- Department of OtorhinolaryngologyRadboud University Medical CenterNijmegenThe Netherlands
- Donders Institute for Brain, Cognition, and BehaviorNijmegenThe Netherlands
| | - Roxana A. Radu
- Department of OphthalmologyDavid Geffen School of MedicineUCLA Stein Eye InstituteUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | - Gabriel H. Travis
- Department of OphthalmologyDavid Geffen School of MedicineUCLA Stein Eye InstituteUniversity of California Los AngelesLos AngelesCaliforniaUSA
- Department of Biological ChemistryUniversity of CaliforniaLos Angeles School of MedicineLos AngelesCaliforniaUSA
| | - Michelle Carey
- UCD School of Mathematics & StatisticsUniversity College DublinDublinIreland
| | - Oliver E. Blacque
- UCD School of Biomolecular and Biomedical ScienceUniversity College DublinDublinIreland
- UCD Conway InstituteUniversity College DublinDublinIreland
| | - Breandán N. Kennedy
- UCD School of Biomolecular and Biomedical ScienceUniversity College DublinDublinIreland
- UCD Conway InstituteUniversity College DublinDublinIreland
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18
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Lima de Carvalho JR, Tsang SH, Sparrow JR. VITAMIN A DEFICIENCY MONITORED BY QUANTITATIVE SHORT WAVELENGTH FUNDUS AUTOFLUORESCENCE IN A CASE OF BARIATRIC SURGERY. Retin Cases Brief Rep 2022; 16:218-221. [PMID: 31599792 PMCID: PMC7182472 DOI: 10.1097/icb.0000000000000931] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND/PURPOSE Bariatric surgery is recognized as a treatment option for obesity. However, the cost-efficiency of screening for serum vitamin A and the effectiveness of its oral supplementation in these patients remain unclear. Here, we report a case in which vitamin A and carotenoid deficiency after bariatric surgery were monitored by noninvasive quantitative fundus autofluorescence imaging. METHODS Case report. RESULTS A 62-year-old man presented with a history of progressive night blindness. He had duodenal switch surgery 13 years earlier. One year before the initial visit, he had begun oral supplements of vitamins A. Short wavelength fundus autofluorescence images acquired for quantitative fundus autofluorescence revealed an intensity that was lower than the healthy-eye range. Scotopic rod-specific full-field electroretinograms were extinguished. These findings were consistent with vitamin A deficiency. The patient was given intramuscular vitamin A injections. At follow-up, quantitative fundus autofluorescence improved, ERG increased to normal, but macular pigment was unchanged. CONCLUSION Oral vitamin A supplementation may not be sufficient after mal-absorptive surgery and a quantitative and noninvasive short wavelength fundus autofluorescence imaging technique may be useful to monitor the status of vitamin A and the carotenoids comprising macular pigment in the retina.
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Affiliation(s)
- Jose Ronaldo Lima de Carvalho
- Department of Ophthalmology, Columbia University, New York, New York
- Department of Ophthalmology, Empresa Brasileira de Servicos Hospitalares (EBSERH)—Hospital das Clinicas de Pernambuco (HCPE), Federal University of Pernambuco (UFPE), Recife, Brazil
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil; and
| | - Stephen H. Tsang
- Department of Ophthalmology, Columbia University, New York, New York
- Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Janet R. Sparrow
- Department of Ophthalmology, Columbia University, New York, New York
- Department of Pathology and Cell Biology, Columbia University, New York, New York
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19
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Mucciolo DP, Giorgio D, Lippera M, Dattilo V, Passerini I, Pelo E, Sodi A, Virgili G, Giansanti F, Murro V. Choroidal Caverns in Stargardt Disease. Invest Ophthalmol Vis Sci 2022; 63:25. [PMID: 35156991 PMCID: PMC8857610 DOI: 10.1167/iovs.63.2.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose To report choroidal caverns in patients affected by recessive Stargardt disease (STGD1) and to investigate its clinical features. Methods Retrospective analysis of STGD1 patients recruited at the Regional Reference Center for Hereditary Retinal Degenerations at the Eye Clinic in Florence from 2012 to 2017. Patients included in the study underwent a complete ophthalmic examination including best-corrected visual acuity, color fundus photography, fundus autofluorescence, optical coherence tomography (OCT) and OCT angiography. Results Eighty-six patients (172 eyes) were included in the study. Twenty-three eyes (13.3%) of 21 patients presented choroidal caverns. The total number of detected choroidal caverns was 63. Choroidal caverns were only present in patients with stage III and IV STGD. Interestingly, patients with choroidal caverns presented larger macular atrophy (20.53 ± 16.9 mm2 vs. 18.11 ± 20.39 mm2), worse visual acuity (1.03 ± 0.29 vs. 0.83 ± 0.26), and a thinner choroidal thickness (245.9 ± 88.7 vs. 266.0 ± 110.5 µm). Conclusions Choroidal caverns are present only in the advanced stage of STGD1, and a possible degenerative origin of the finding has been hypothesized.
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Affiliation(s)
- Dario Pasquale Mucciolo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy.,Ophthalmology Unit, San Jacopo Hospital, Pistoia, Italy
| | - Dario Giorgio
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Myrta Lippera
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Valeria Dattilo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Elisabetta Pelo
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Andrea Sodi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Gianni Virgili
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy.,Fondazione GB Bietti, Roma, Italy
| | - Fabrizio Giansanti
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
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20
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Sajovic J, Meglič A, Glavač D, Markelj Š, Hawlina M, Fakin A. The Role of Vitamin A in Retinal Diseases. Int J Mol Sci 2022; 23:1014. [PMID: 35162940 PMCID: PMC8835581 DOI: 10.3390/ijms23031014] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 12/24/2022] Open
Abstract
Vitamin A is an essential fat-soluble vitamin that occurs in various chemical forms. It is essential for several physiological processes. Either hyper- or hypovitaminosis can be harmful. One of the most important vitamin A functions is its involvement in visual phototransduction, where it serves as the crucial part of photopigment, the first molecule in the process of transforming photons of light into electrical signals. In this process, large quantities of vitamin A in the form of 11-cis-retinal are being isomerized to all-trans-retinal and then quickly recycled back to 11-cis-retinal. Complex machinery of transporters and enzymes is involved in this process (i.e., the visual cycle). Any fault in the machinery may not only reduce the efficiency of visual detection but also cause the accumulation of toxic chemicals in the retina. This review provides a comprehensive overview of diseases that are directly or indirectly connected with vitamin A pathways in the retina. It includes the pathophysiological background and clinical presentation of each disease and summarizes the already existing therapeutic and prospective interventions.
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Affiliation(s)
- Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Andrej Meglič
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Damjan Glavač
- Department of Molecular Genetics, Institute of Pathology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
| | - Špela Markelj
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
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21
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Molday RS, Garces FA, Scortecci JF, Molday LL. Structure and function of ABCA4 and its role in the visual cycle and Stargardt macular degeneration. Prog Retin Eye Res 2021; 89:101036. [PMID: 34954332 DOI: 10.1016/j.preteyeres.2021.101036] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/07/2021] [Accepted: 12/13/2021] [Indexed: 12/17/2022]
Abstract
ABCA4 is a member of the superfamily of ATP-binding cassette (ABC) transporters that is preferentially localized along the rim region of rod and cone photoreceptor outer segment disc membranes. It uses the energy from ATP binding and hydrolysis to transport N-retinylidene-phosphatidylethanolamine (N-Ret-PE), the Schiff base adduct of retinal and phosphatidylethanolamine, from the lumen to the cytoplasmic leaflet of disc membranes. This ensures that all-trans-retinal and excess 11-cis-retinal are efficiently cleared from photoreceptor cells thereby preventing the accumulation of toxic retinoid compounds. Loss-of-function mutations in the gene encoding ABCA4 cause autosomal recessive Stargardt macular degeneration, also known as Stargardt disease (STGD1), and related autosomal recessive retinopathies characterized by impaired central vision and an accumulation of lipofuscin and bis-retinoid compounds. High resolution structures of ABCA4 in its substrate and nucleotide free state and containing bound N-Ret-PE or ATP have been determined by cryo-electron microscopy providing insight into the molecular architecture of ABCA4 and mechanisms underlying substrate recognition and conformational changes induced by ATP binding. The expression and functional characterization of a large number of disease-causing missense ABCA4 variants have been determined. These studies have shed light into the molecular mechanisms underlying Stargardt disease and a classification that reliably predicts the effect of a specific missense mutation on the severity of the disease. They also provide a framework for developing rational therapeutic treatments for ABCA4-associated diseases.
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Affiliation(s)
- Robert S Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada; Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, B.C., Canada.
| | - Fabian A Garces
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
| | | | - Laurie L Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
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22
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Huang D, Heath Jeffery RC, Aung-Htut MT, McLenachan S, Fletcher S, Wilton SD, Chen FK. Stargardt disease and progress in therapeutic strategies. Ophthalmic Genet 2021; 43:1-26. [PMID: 34455905 DOI: 10.1080/13816810.2021.1966053] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background: Stargardt disease (STGD1) is an autosomal recessive retinal dystrophy due to mutations in ABCA4, characterized by subretinal deposition of lipofuscin-like substances and bilateral centrifugal vision loss. Despite the tremendous progress made in the understanding of STGD1, there are no approved treatments to date. This review examines the challenges in the development of an effective STGD1 therapy.Materials and Methods: A literature review was performed through to June 2021 summarizing the spectrum of retinal phenotypes in STGD1, the molecular biology of ABCA4 protein, the in vivo and in vitro models used to investigate the mechanisms of ABCA4 mutations and current clinical trials.Results: STGD1 phenotypic variability remains an challenge for clinical trial design and patient selection. Pre-clinical development of therapeutic options has been limited by the lack of animal models reflecting the diverse phenotypic spectrum of STDG1. Patient-derived cell lines have facilitated the characterization of splice mutations but the clinical presentation is not always predicted by the effect of specific mutations on retinoid metabolism in cellular models. Current therapies primarily aim to delay vision loss whilst strategies to restore vision are less well developed.Conclusions: STGD1 therapy development can be accelerated by a deeper understanding of genotype-phenotype correlations.
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Affiliation(s)
- Di Huang
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Rachael C Heath Jeffery
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia
| | - May Thandar Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Samuel McLenachan
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.,Perron Institute for Neurological and Translational Science & the University of Western Australia, Nedlands, Western Australia, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), the University of Western Australia, Nedlands, Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.,Department of Ophthalmology, Perth Children's Hospital, Nedlands, Western Australia, Australia
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23
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Al-Khuzaei S, Broadgate S, Foster CR, Shah M, Yu J, Downes SM, Halford S. An Overview of the Genetics of ABCA4 Retinopathies, an Evolving Story. Genes (Basel) 2021; 12:1241. [PMID: 34440414 PMCID: PMC8392661 DOI: 10.3390/genes12081241] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Stargardt disease (STGD1) and ABCA4 retinopathies (ABCA4R) are caused by pathogenic variants in the ABCA4 gene inherited in an autosomal recessive manner. The gene encodes an importer flippase protein that prevents the build-up of vitamin A derivatives that are toxic to the RPE. Diagnosing ABCA4R is complex due to its phenotypic variability and the presence of other inherited retinal dystrophy phenocopies. ABCA4 is a large gene, comprising 50 exons; to date > 2000 variants have been described. These include missense, nonsense, splicing, structural, and deep intronic variants. Missense variants account for the majority of variants in ABCA4. However, in a significant proportion of patients with an ABCA4R phenotype, a second variant in ABCA4 is not identified. This could be due to the presence of yet unknown variants, or hypomorphic alleles being incorrectly classified as benign, or the possibility that the disease is caused by a variant in another gene. This underlines the importance of accurate genetic testing. The pathogenicity of novel variants can be predicted using in silico programs, but these rely on databases that are not ethnically diverse, thus highlighting the need for studies in differing populations. Functional studies in vitro are useful towards assessing protein function but do not directly measure the flippase activity. Obtaining an accurate molecular diagnosis is becoming increasingly more important as targeted therapeutic options become available; these include pharmacological, gene-based, and cell replacement-based therapies. The aim of this review is to provide an update on the current status of genotyping in ABCA4 and the status of the therapeutic approaches being investigated.
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Affiliation(s)
- Saoud Al-Khuzaei
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; (S.A.-K.); (M.S.)
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | - Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | | | - Mital Shah
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; (S.A.-K.); (M.S.)
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | - Susan M. Downes
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; (S.A.-K.); (M.S.)
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
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24
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Piotter E, McClements ME, MacLaren RE. Therapy Approaches for Stargardt Disease. Biomolecules 2021; 11:1179. [PMID: 34439845 PMCID: PMC8393614 DOI: 10.3390/biom11081179] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/27/2021] [Accepted: 08/05/2021] [Indexed: 12/14/2022] Open
Abstract
Despite being the most prevalent cause of inherited blindness in children, Stargardt disease is yet to achieve the same clinical trial success as has been achieved for other inherited retinal diseases. With an early age of onset and continual progression of disease over the life course of an individual, Stargardt disease appears to lend itself to therapeutic intervention. However, the aetiology provides issues not encountered with the likes of choroideremia and X-linked retinitis pigmentosa and this has led to a spectrum of treatment strategies that approach the problem from different aspects. These include therapeutics ranging from small molecules and anti-sense oligonucleotides to viral gene supplementation and cell replacement. The advancing development of CRISPR-based molecular tools is also likely to contribute to future therapies by way of genome editing. In this we review, we consider the most recent pre-clinical and clinical trial data relating to the different strategies being applied to the problem of generating a treatment for the large cohort of Stargardt disease patients worldwide.
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Affiliation(s)
- Elena Piotter
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Michelle E McClements
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
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25
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Nutraceutical Supplementation Ameliorates Visual Function, Retinal Degeneration, and Redox Status in rd10 Mice. Antioxidants (Basel) 2021; 10:antiox10071033. [PMID: 34206804 PMCID: PMC8300708 DOI: 10.3390/antiox10071033] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/17/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future.
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26
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Dhooge PPA, Runhart EH, Li CHZ, de Kat Angelino CM, Hoyng CB, van der Molen RG, den Hollander AI. Systemic complement activation levels in Stargardt disease. PLoS One 2021; 16:e0253716. [PMID: 34170959 PMCID: PMC8232401 DOI: 10.1371/journal.pone.0253716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/10/2021] [Indexed: 12/16/2022] Open
Abstract
Purpose Preclinical research provides evidence for the complement system as a potential common pathway in Stargardt disease (STGD1) and age-related macular degeneration (AMD) leading to retinal pigment epithelium (RPE) loss. However, systemic complement activation has not yet been assessed in STGD1 patients. We conducted a cross-sectional case-control study to assess systemic complement activation in STGD1 patients and its association with disease severity. Methods Systemic concentrations of complement component C3 and its degradation product C3d were compared between 80 STGD1 patients and 80 controls that were frequency matched for age and sex. The C3d/C3 ratio was used as parameter of systemic complement activation. Within the STGD1 cohort, we additionally examined the association between the C3d/C3 ratio, demographic and behavioural factors (age, sex, smoking and BMI), and measures of disease severity (age at onset, visual acuity, and area of atrophy). Results The C3d/C3 ratio did not significantly differ between patients (mean C3d/C3 ratio 3.5±1.4) and controls (mean C3d/C3 ratio 3.6±1.0), mean difference -0.156 (p = 0.804, independent samples t-test). The overall effect size was 8% (95% confidence interval, 3–15%). Elevated C3d/C3 ratios (>8.1) were found in three patients who all had a concomitant inflammatory condition at the time of blood draw. Within the patient cohort, C3 levels were associated with sex (mean difference -134, p = 0.001, independent samples t-test) and BMI (correlation coefficient 0.463, p<0.001, Spearman’s Correlation). Conclusions Systemic complement levels were not elevated in STGD1 patients compared to age and sex matched controls and was not associated with STGD1 severity. Considering the continued absent proof of a systemic contribution of the complement system to RPE loss in STGD1 patients, we hypothesize that complement activation in STGD1 is more likely a local process. In light of upcoming complement-targeted therapies, further studies are needed that measure complement levels in the eye of STGD1 patients.
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Affiliation(s)
- Patty P. A. Dhooge
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Esmee H. Runhart
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Catherina H. Z. Li
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Corrie M. de Kat Angelino
- Department of Laboratory Medicine, Laboratory of Medical Immunology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carel B. Hoyng
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Renate G. van der Molen
- Department of Laboratory Medicine, Laboratory of Medical Immunology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I. den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
- * E-mail:
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27
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Absence of Genotype/Phenotype Correlations Requires Molecular Diagnostic to Ascertain Stargardt and Stargardt-Like Swiss Patients. Genes (Basel) 2021; 12:genes12060812. [PMID: 34073554 PMCID: PMC8229718 DOI: 10.3390/genes12060812] [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: 05/04/2021] [Revised: 05/20/2021] [Accepted: 05/25/2021] [Indexed: 11/25/2022] Open
Abstract
We genetically characterized 22 Swiss patients who had been diagnosed with Stargardt disease after clinical examination. We identified in 11 patients (50%) pathogenic bi-allelic ABCA4 variants, c.1760+2T>C and c.4496T>C being novel. The dominantly inherited pathogenic ELOVL4 c.810C>G p.(Tyr270*) and PRPH2-c.422A>G p.(Tyr141Cys) variants were identified in eight (36%) and three patients (14%), respectively. All patients harboring the ELOVL4 c.810C>G p.(Tyr270*) variant originated from the same small Swiss area, identifying a founder mutation. In the ABCA4 and ELOVL4 cohorts, the clinical phenotypes of “flecks”, “atrophy”, and “bull’s eye like” were observed by fundus examination. In the small number of patients harboring the pathogenic PRPH2 variant, we could observe both “flecks” and “atrophy” clinical phenotypes. The onset of disease, progression of visual acuity and clinical symptoms, inheritance patterns, fundus autofluorescence, and optical coherence tomography did not allow discrimination between the genetically heterogeneous Stargardt patients. The genetic heterogeneity observed in the relatively small Swiss population should prompt systematic genetic testing of clinically diagnosed Stargardt patients. The resulting molecular diagnostic is required to prevent potentially harmful vitamin A supplementation, to provide genetic counseling with respect to inheritance, and to schedule appropriate follow-up visits in the presence of increased risk of choroidal neovascularization.
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28
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Birtel J, Yusuf IH, Priglinger C, Rudolph G, Charbel Issa P. Diagnosis of Inherited Retinal Diseases. Klin Monbl Augenheilkd 2021; 238:249-259. [PMID: 33784788 DOI: 10.1055/a-1388-7236] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Inherited retinal diseases are a frequent cause of severe visual impairment or blindness in children and adults of working age. Across this group of diseases, there is great variability in the degree of visual impairment, the impact on everyday life, disease progression, and the suitability to therapeutic intervention. Therefore, an early and precise diagnosis is crucial for patients and their families. Characterizing inherited retinal diseases involves a detailed medical history, clinical examination with testing of visual function, multimodal retinal imaging as well as molecular genetic testing. This may facilitate a distinction between different inherited retinal diseases, as well as a differentiation from monogenic systemic diseases with retinal involvement, and from mimicking diseases.
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Affiliation(s)
- Johannes Birtel
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Imran H Yusuf
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Claudia Priglinger
- Department of Ophthalmology, University Hospital, LMU Munich, Munich, Germany
| | - Günter Rudolph
- Department of Ophthalmology, University Hospital, LMU Munich, Munich, Germany
| | - Peter Charbel Issa
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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29
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Wu J, Cui D, Li H, Zeng J. Protective effects of NAC and salubrinal on apoptosis of retinal pigment epithelial cells induced by all-trans retinoic acid. Eur J Ophthalmol 2021; 32:395-401. [PMID: 33726556 DOI: 10.1177/11206721211000674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE Accumulation of endogenous all-trans retinoic acid (ATRA) plays a role in the degeneration of photoreceptor cells and retinal pigment epithelium (RPE) cells, contributing to age-related macular degeneration (AMD). This study attempted to investigate the influence of antioxidant N-acetylcysteine (NAC) and selective endoplasmic reticulum stress (ERS) inhibitor salubrinal on apoptosis of ARPE-19 cells induced by ATRA. METHODS The RPE cell line (ARPE-19) was treated with ATRA, ATRA+NAC, ATRA+salubrinal or ATRA+NAC+salubrinal and the control was untreated. After 24 h of cell culture, the levels of apoptosis, multicaspase and reactive oxygen species (ROS) were detected by flow cytometry. Western blot analysis was employed to detect the expression of vascular endothelial growth factor-A (VEGF-A), C/EBP homologous protein (CHOP) and cleaved caspase-3 in the groups. RESULTS The results of flow cytometry showed that NAC and salubrinal decreased the levels of apoptosis, ROS and multicaspase. ATRA increased VEGF-A levels associated with neovascularisation. NAC and salubrinal inhibited an increase in VEGF-A, CHOP and caspase-3 caused by ATRA in ARPE-19 cells. CONCLUSIONS In ARPE-19 cells, the levels of ROS and ERS can be increased by ATRA, contributing to apoptosis, which can be effectively inhibited by NAC and salubrinal. Thus, ATRA may play an important role in the prevention, diagnosis and treatment of age-related macular degeneration.
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Affiliation(s)
- Juan Wu
- Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China
| | - Dongmei Cui
- Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China
| | - Honghui Li
- Chengdu Air Eye Hospital, Sichuan, China
| | - Junwen Zeng
- Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China
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30
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Kim HJ, Sparrow JR. Bisretinoid phospholipid and vitamin A aldehyde: shining a light. J Lipid Res 2021; 62:100042. [PMID: 32371567 PMCID: PMC7933493 DOI: 10.1194/jlr.tr120000742] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/29/2020] [Indexed: 12/17/2022] Open
Abstract
Vitamin A aldehyde covalently bound to opsin protein is embedded in a phospholipid-rich membrane that supports photon absorption and phototransduction in photoreceptor cell outer segments. Following absorption of a photon, the 11-cis-retinal chromophore of visual pigment in photoreceptor cells isomerizes to all-trans-retinal. To maintain photosensitivity 11-cis-retinal must be replaced. At the same time, however, all-trans-retinal has to be handled so as to prevent nonspecific aldehyde activity. Some molecules of retinaldehyde upon release from opsin are efficiently reduced to retinol. Other molecules are released into the lipid phase of the disc membrane where they form a conjugate [N-retinylidene-PE (NRPE)] through a Schiff base linkage with PE. The reversible formation of NRPE serves as a transient sink for retinaldehyde that is intended to return retinaldehyde to the visual cycle. However, if instead of hydrolyzing to PE and retinaldehyde, NRPE reacts with a second molecule of retinaldehyde, a synthetic pathway is initiated that leads to the formation of multiple species of unwanted bisretinoid fluorophores. We report on recently identified members of the bisretinoid family, some of which differ with respect to the acyl chains associated with the glycerol backbone. We discuss processing of the lipid moieties of these fluorophores in lysosomes of retinal pigment epithelial cells, their fluorescence characters, and new findings related to light- and iron-associated oxidation of bisretinoids.
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Affiliation(s)
- Hye Jin Kim
- Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Janet R Sparrow
- Department of Ophthalmology, Columbia University, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.
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Mucciolo DP, Lippera M, Giorgio D, Sodi A, Passerini I, Cipollini F, Virgili G, Giansanti F, Murro V. Outer nuclear layer relevance in visual function correlated to quantitative enface OCT parameters in Stargardt disease. Eur J Ophthalmol 2021; 31:3248-3258. [PMID: 33508977 DOI: 10.1177/1120672121990579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To evaluate the correlation between Best Corrected Visual Acuity (BCVA) and the following parameters in Stargardt Disease (STGD): Central Retinal Thickness (CR-T), Central Outer Nuclear Layer Thickness (C-ONL-T), Areas of macular Photoreceptor loss (PHRa), and Retinal Pigment Epithelium (RPE) loss (RPEa). METHODS A total of 64 eyes of 32 STGD patients were included in the study. All patients received a comprehensive ophthalmological examination, color fundus photographs, fundus auto-fluorescence imaging, and Optical Coherence Tomography (OCT). The CR-T and C-ONL-T were evaluated from standard SD-OCT scans. The PHRa and RPEa were calculated from enface OCT scans (sub RPE slab and photoreceptor slab). The collected OCT parameters were evaluated for possible association with BCVA. RESULTS The mean macular PHRa and RPEa was 16.16 ± 13.36 and 12.05 ± 12.57 mm2 respectively. The mean CR-T measured 120.78 ± 41.49 μm while the mean C-ONL-T was assessed at 4.60 ± 13.73 μm. BCVA showed the highest correlation with the C-ONL-T (r = -0.72; p < 0.001) while there was no correlation with the CR-T (r = -0.17; p = 1.00). CONCLUSIONS Enface OCT permits a rapid and precise quantitative evaluation of the macular PHR and RPE atrophy area in STGD. Nonetheless, the OCT parameter that showed the highest correlation with visual acuity in STGD was the ONL thickness.
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Affiliation(s)
- Dario Pasquale Mucciolo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Myrta Lippera
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Dario Giorgio
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Andrea Sodi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Francesca Cipollini
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Gianni Virgili
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Fabrizio Giansanti
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
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32
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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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Cell-Type-Specific Complement Profiling in the ABCA4 -/- Mouse Model of Stargardt Disease. Int J Mol Sci 2020; 21:ijms21228468. [PMID: 33187113 PMCID: PMC7697683 DOI: 10.3390/ijms21228468] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/02/2020] [Accepted: 11/09/2020] [Indexed: 12/13/2022] Open
Abstract
Stargardt macular degeneration is an inherited retinal disease caused by mutations in the ATP-binding cassette subfamily A member 4 (ABCA4) gene. Here, we characterized the complement expression profile in ABCA4−/− retinae and aligned these findings with morphological markers of retinal degeneration. We found an enhanced retinal pigment epithelium (RPE) autofluorescence, cell loss in the inner retina of ABCA4−/− mice and demonstrated age-related differences in complement expression in various retinal cell types irrespective of the genotype. However, 24-week-old ABCA4−/− mice expressed more c3 in the RPE and fewer cfi transcripts in the microglia compared to controls. At the protein level, the decrease of complement inhibitors (complement factor I, CFI) in retinae, as well as an increased C3b/C3 ratio in the RPE/choroid and retinae of ABCA4−/−, mice was confirmed. We showed a corresponding increase of the C3d/C3 ratio in the serum of ABCA4−/− mice, while no changes were observed for CFI. Our findings suggest an overactive complement cascade in the ABCA4−/− retinae that possibly contributes to pathological alterations, including microglial activation and neurodegeneration. Overall, this underpins the importance of well-balanced complement homeostasis to maintain retinal integrity.
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Collin GB, Gogna N, Chang B, Damkham N, Pinkney J, Hyde LF, Stone L, Naggert JK, Nishina PM, Krebs MP. Mouse Models of Inherited Retinal Degeneration with Photoreceptor Cell Loss. Cells 2020; 9:cells9040931. [PMID: 32290105 PMCID: PMC7227028 DOI: 10.3390/cells9040931] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degeneration (RD) leads to the impairment or loss of vision in millions of individuals worldwide, most frequently due to the loss of photoreceptor (PR) cells. Animal models, particularly the laboratory mouse, have been used to understand the pathogenic mechanisms that underlie PR cell loss and to explore therapies that may prevent, delay, or reverse RD. Here, we reviewed entries in the Mouse Genome Informatics and PubMed databases to compile a comprehensive list of monogenic mouse models in which PR cell loss is demonstrated. The progression of PR cell loss with postnatal age was documented in mutant alleles of genes grouped by biological function. As anticipated, a wide range in the onset and rate of cell loss was observed among the reported models. The analysis underscored relationships between RD genes and ciliary function, transcription-coupled DNA damage repair, and cellular chloride homeostasis. Comparing the mouse gene list to human RD genes identified in the RetNet database revealed that mouse models are available for 40% of the known human diseases, suggesting opportunities for future research. This work may provide insight into the molecular players and pathways through which PR degenerative disease occurs and may be useful for planning translational studies.
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Affiliation(s)
- Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Navdeep Gogna
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Nattaya Damkham
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Jai Pinkney
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lillian F. Hyde
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Jürgen K. Naggert
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
| | - Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
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Lima de Carvalho JR, Kim HJ, Ueda K, Zhao J, Owji AP, Yang T, Tsang SH, Sparrow JR. Effects of deficiency in the RLBP1-encoded visual cycle protein CRALBP on visual dysfunction in humans and mice. J Biol Chem 2020; 295:6767-6780. [PMID: 32188692 PMCID: PMC7212638 DOI: 10.1074/jbc.ra120.012695] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/04/2020] [Indexed: 12/16/2022] Open
Abstract
Mutations in retinaldehyde-binding protein 1 (RLBP1), encoding the visual cycle protein cellular retinaldehyde-binding protein (CRALBP), cause an autosomal recessive form of retinal degeneration. By binding to 11-cis-retinoid, CRALBP augments the isomerase activity of retinoid isomerohydrolase RPE65 (RPE65) and facilitates 11-cis-retinol oxidation to 11-cis-retinal. CRALBP also maintains the 11-cis configuration and protects against unwanted retinaldehyde activity. Studying a sibling pair that is compound heterozygous for mutations in RLBP1/CRALBP, here we expand the phenotype of affected individuals, elucidate a previously unreported phenotype in RLBP1/CRALBP carriers, and demonstrate consistencies between the affected individuals and Rlbp1/Cralbp−/− mice. In the RLBP1/CRALBP-affected individuals, nonrecordable rod-specific electroretinogram traces were recovered after prolonged dark adaptation. In ultrawide-field fundus images, we observed radially arranged puncta typical of RLBP1/CRALBP-associated disease. Spectral domain-optical coherence tomography (SD-OCT) revealed hyperreflective aberrations within photoreceptor-associated bands. In short-wavelength fundus autofluorescence (SW-AF) images, speckled hyperautofluorescence and mottling indicated macular involvement. In both the affected individuals and their asymptomatic carrier parents, reduced SW-AF intensities, measured as quantitative fundus autofluorescence (qAF), indicated chronic impairment in 11-cis-retinal availability and provided information on mutation severity. Hypertransmission of the SD-OCT signal into the choroid together with decreased near-infrared autofluorescence (NIR-AF) provided evidence for retinal pigment epithelial cell (RPE) involvement. In Rlbp1/Cralbp−/− mice, reduced 11-cis-retinal levels, qAF and NIR-AF intensities, and photoreceptor loss were consistent with the clinical presentation of the affected siblings. These findings indicate that RLBP1 mutations are associated with progressive disease involving RPE atrophy and photoreceptor cell degeneration. In asymptomatic carriers, qAF disclosed previously undetected visual cycle deficiency.
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Affiliation(s)
| | - Hye Jin Kim
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York 10032
| | - Keiko Ueda
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York 10032
| | - Jin Zhao
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York 10032
| | - Aaron P Owji
- Department of Pharmacology, Columbia University Irving Medical Center, New York, New York 10032
| | - Tingting Yang
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York 10032
| | - Stephen H Tsang
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York 10032.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
| | - Janet R Sparrow
- Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York 10032 .,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
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Sheludchenko VM, Budzinskaya MV, Ronzina IA, Smirnova TV. [Effectiveness of new techniques of intraocular stem cells transplantation in the treatment of retinitis pigmentosa]. Vestn Oftalmol 2019; 135:267-271. [PMID: 31691671 DOI: 10.17116/oftalma2019135052267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Retinitis pigmentosa (RP) is a degenerative retinal disease that leads to blindness. Recently, treatment methods based on new technologies have emerged. Among them is stem cells transplantation (SC). PURPOSE To make a systematic evaluation of the results of control clinical studies of cellular technologies for the treatment of RP. MATERIAL AND METHODS The key words - retinitis pigmentosa, stem cells, control study - were used to search literature databases PubMed (250), WOS (172), MEDLINE (32) for the last 5 years. According to preliminary criteria, 88 articles were selected, according to final criteria - 4 articles. A total of 25 patients with RP were found. Control points of the analysis were: baseline, 3 months and 12 months. Methods of analysis (events): visual acuity (VA) and flash electroretinogram (f-ERG). RESULTS There was no VA increase in 15 (60%) of the blind (or with negligible vision of less than 20/1600 ENDRS) patients, and the f-ERG was unrecordable. In 10 patients (40%), VA improved from 0.1 to 0.4 logMAR and the amplitude of f-ERG increased at about 3 months after injection. At 12 months, the effect returned to the baseline values. CONCLUSION The use of SC transplantation technology in RP helps achieve short-term (up to 3 months) positive changes in VA and f-ERG, which depend on the initial stage of RP and do not remain in the final stage. This evokes a question of repeated use of SC transplantation in the same patient.
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Affiliation(s)
- V M Sheludchenko
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - M V Budzinskaya
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - I A Ronzina
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - T V Smirnova
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
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Strauss RW, Kong X, Ho A, Jha A, West S, Ip M, Bernstein PS, Birch DG, Cideciyan AV, Michaelides M, Sahel JA, Sunness JS, Traboulsi EI, Zrenner E, Pitetta S, Jenkins D, Hariri AH, Sadda S, Scholl HPN. Progression of Stargardt Disease as Determined by Fundus Autofluorescence Over a 12-Month Period: ProgStar Report No. 11. JAMA Ophthalmol 2019; 137:1134-1145. [PMID: 31369039 DOI: 10.1001/jamaophthalmol.2019.2885] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Importance Sensitive outcome measures for disease progression are needed for treatment trials of Stargardt disease. Objective To estimate the progression rate of atrophic lesions in the prospective Natural History of the Progression of Atrophy Secondary to Stargardt Disease (ProgStar) study over a 12-month period. Design, Setting, and Participants This multicenter prospective cohort study was conducted in an international selection of tertiary referral centers from October 21, 2013, to February 15, 2017. Patients who were affected by Stargardt disease, aged 6 years and older at baseline, and harboring disease-causing variants of the ABCA4 gene were enrolled at 9 centers in the United States, United Kingdom, and continental Europe. Data analysis occurred from November 2016 to January 2017. Exposures Autofluorescence images obtained with a standard protocol were sent to a central reading center, and areas of definitely decreased autofluorescence, questionably decreased autofluorescence, and the total combined area of decreased autofluorescence were outlined and quantified. Progression rates were estimated from linear mixed models with time as the independent variable. Main Outcomes and Measures Yearly rate of progression, using the growth of atrophic lesions measured by autofluorescence imaging. Results A total of 259 study participants (488 eyes; 230 individuals [88.8%] were examined in both eyes) were enrolled (mean [SD] age at first visit, 33.3 [15.1] years; 118 [54.4%] female). Gradable images were available for evaluation for 480 eyes at baseline and 454 eyes after 12 months. At baseline, definitely decreased autofluorescence was present in 306 eyes, and the mean (SD) lesion size was 3.93 (4.37) mm2. The mean total area of decreased autofluorescence at baseline was 4.07 (4.04) mm2. The estimated progression of definitely decreased autofluorescence was 0.76 (95% CI, 0.54-0.97) mm2 per year (P < .001), and the total area of both questionably and definitely decreased autofluorescence was 0.64 (95% CI, 0.50-0.78) mm2 per year (P < .001). Both progression rates depended on initial lesion size. Conclusions and Relevance In Stargardt disease, autofluorescence imaging may serve as a monitoring tool and definitely decreased autofluorescence and total area as outcome measures for interventional clinical trials that aim to slow disease progression. Rates of progression depended mainly on initial lesion size.
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Affiliation(s)
- Rupert W Strauss
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.,Moorfields Eye Hospital National Health Services Foundation Trust and UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Department of Ophthalmology, Johannes Kepler University Clinic Linz, Linz, Austria.,Department of Ophthalmology, Medical University Graz, Graz, Austria
| | - Xiangrong Kong
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.,Department of Biostatistics and Epidemiology, University of Massachusetts, Amherst
| | - Alexander Ho
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - Anamika Jha
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - Sheila West
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
| | - Michael Ip
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - Paul S Bernstein
- Moran Eye Center, University of Utah School of Medicine, Salt Lake City
| | | | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Michel Michaelides
- Moorfields Eye Hospital National Health Services Foundation Trust and UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - José-Alain Sahel
- Sorbonne Universités, University Pierre et Marie Curie Université de Paris 06, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de la Vision, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France
| | - Janet S Sunness
- Hoover Low Vision Rehabilitation Services, Greater Baltimore Medical Center, University of Maryland School of Medicine, Baltimore, Maryland
| | | | - Eberhart Zrenner
- Center for Ophthalmology, Eberhard-Karls University Hospital, Tübingen, Germany
| | - Sean Pitetta
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - Dennis Jenkins
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - Amir Hossein Hariri
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - SriniVas Sadda
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - Hendrik P N Scholl
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.,Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland
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Dyka FM, Molday LL, Chiodo VA, Molday RS, Hauswirth WW. Dual ABCA4-AAV Vector Treatment Reduces Pathogenic Retinal A2E Accumulation in a Mouse Model of Autosomal Recessive Stargardt Disease. Hum Gene Ther 2019; 30:1361-1370. [PMID: 31418294 DOI: 10.1089/hum.2019.132] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Autosomal recessive Stargardt disease is the most common inherited macular degeneration in humans. It is caused by mutations in the retina-specific ATP binding cassette transporter A4 (ABCA4) that is essential for the clearance of all-trans-retinal from photoreceptor cells. Loss of this function results in the accumulation of toxic bisretinoids in the outer segment disk membranes and their subsequent transfer into adjacent retinal pigment epithelium (RPE) cells. This ultimately leads to the Stargardt disease phenotype of increased retinal autofluorescence and progressive RPE and photoreceptor cell loss. Adeno-associated virus (AAV) vectors have been widely used in gene therapeutic applications, but their limited cDNA packaging capacity of ∼4.5 kb has impeded their use for transgenes exceeding this limit. AAV dual vectors were developed to overcome this size restriction. In this study, we have evaluated the in vitro expression of ABCA4 using three options: overlap, transplicing, and hybrid ABCA4 dual vector systems. The hybrid system was the most efficient of these dual vector alternatives and used to express the full-length ABCA4 in Abca4-/- mice. The full-length ABCA4 protein correctly localized to photoreceptor outer segments. Moreover, treatment of Abca4-/- mice with this ABCA4 hybrid dual vector system resulted in a reduced accumulation of the lipofuscin/N-retinylidene-N-retinylethanolamine (A2E) autofluorescence in vivo, and retinal A2E quantification supported these findings. These results show that the hybrid AAV dual vector option is both safe and therapeutic in mice, and the delivered ABCA4 transgene is functional and has a significant effect on reducing A2E accumulation in the Abca4-/- mouse model of Stargardt disease.
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Affiliation(s)
- Frank M Dyka
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Laurie L Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Vince A Chiodo
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
| | - Robert S Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - William W Hauswirth
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida
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Non-viral Gene Therapy for Stargardt Disease with ECO/pRHO-ABCA4 Self-Assembled Nanoparticles. Mol Ther 2019; 28:293-303. [PMID: 31611143 DOI: 10.1016/j.ymthe.2019.09.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/10/2019] [Accepted: 09/06/2019] [Indexed: 12/20/2022] Open
Abstract
Stargardt disease (STGD) is an autosomal recessive retinal disorder caused by a monogenic ABCA4 mutation. Currently, there is no effective therapy to cure Stargardt disease. The replacement of mutated ABCA4 with a functional gene remains an attractive strategy. In this study, we have developed a non-viral gene therapy using nanoparticles self-assembled by a multifunctional pH-sensitive amino lipid ECO and a therapeutic ABCA4 plasmid. The nanoparticles mediated efficient intracellular gene transduction in wild-type (WT) and Abca4-/- mice. Specific ABCA4 expression in the outer segment of photoreceptors was achieved by incorporating a rhodopsin promoter into the plasmids. The ECO/pRHO-ABCA4 nanoparticles induced substantial and specific ABCA4 expression for at least 8 months, 35% reduction in A2E accumulation on average, and a delayed Stargardt disease progression for at least 6 months in Abca4-/- mice. ECO/plasmid nanoparticles constitute a promising non-viral gene therapy platform for Stargardt disease and other visual dystrophies.
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40
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Waugh N, Loveman E, Colquitt J, Royle P, Yeong JL, Hoad G, Lois N. Treatments for dry age-related macular degeneration and Stargardt disease: a systematic review. Health Technol Assess 2019; 22:1-168. [PMID: 29846169 DOI: 10.3310/hta22270] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD) is the leading cause of visual loss in older people. Advanced AMD takes two forms, neovascular (wet) and atrophic (dry). Stargardt disease (STGD) is the commonest form of inherited macular dystrophy. OBJECTIVE To carry out a systematic review of treatments for dry AMD and STGD, and to identify emerging treatments where future NIHR research might be commissioned. DESIGN Systematic review. METHODS We searched MEDLINE, EMBASE, Web of Science and The Cochrane Library from 2005 to 13 July 2017 for reviews, journal articles and meeting abstracts. We looked for studies of interventions that aim to preserve or restore vision in people with dry AMD or STGD. The most important outcomes are those that matter to patients: visual acuity (VA), contrast sensitivity, reading speed, ability to drive, adverse effects of treatment, quality of life, progression of disease and patient preference. However, visual loss is a late event and intermediate predictors of future decline were accepted if there was good evidence that they are strong predictors of subsequent visual outcomes. These include changes detectable by investigation, but not necessarily noticed by people with AMD or STGD. ClinicalTrials.gov, the World Health Organization search portal and the UK Clinical Trials gateway were searched for ongoing and recently completed clinical trials. RESULTS The titles and abstracts of 7948 articles were screened for inclusion. The full text of 398 articles were obtained for further screening and checking of references and 112 articles were included in the final report. Overall, there were disappointingly few good-quality studies (including of sufficient size and duration) reporting useful outcomes, particularly in STGD. However we did identify a number of promising research topics, including drug treatments, stem cells, new forms of laser treatment, and implantable intraocular lens telescopes. In many cases, research is already under way, funded by industry or governments. LIMITATIONS In AMD, the main limitation came from the poor quality of much of the evidence. Many studies used VA as their main outcome despite not having sufficient duration to observe changes. The evidence on treatments for STGD is sparse. Most studies tested interventions with no comparison group, were far too short term, and the quality of some studies was poor. FUTURE WORK We think that the topics on which the Health Technology Assessment (HTA) and Efficacy Mechanism and Evaluation (EME) programmes might consider commissioning primary research are in STGD, a HTA trial of fenretinide (ReVision Therapeutics, San Diego, CA, USA), a visual cycle inhibitor, and EME research into the value of lutein and zeaxanthin supplements, using short-term measures of retinal function. In AMD, we suggest trials of fenretinide and of a potent statin. There is epidemiological evidence from the USA that the drug, levodopa, used for treating Parkinson's disease, may reduce the incidence of AMD. We suggest that similar research should be carried out using the large general practice databases in the UK. Ideally, future research should be at earlier stages in both diseases, before vision is impaired, using sensitive measures of macular function. This may require early detection of AMD by screening. STUDY REGISTRATION This study is registered as PROSPERO CRD42016038708. FUNDING The National Institute for Health Research HTA programme.
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Affiliation(s)
- Norman Waugh
- Division of Health Sciences, University of Warwick, Coventry, UK
| | | | | | - Pamela Royle
- Division of Health Sciences, University of Warwick, Coventry, UK
| | | | | | - Noemi Lois
- Ophthalmology, Royal Victoria Hospital, Belfast, UK.,Wellcome-Wolfson Centre for Experimental Medicine, Queens University, Belfast, UK
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Vitamins and Mineral Supplements for Retinitis Pigmentosa. J Ophthalmol 2019; 2019:8524607. [PMID: 30918719 PMCID: PMC6409042 DOI: 10.1155/2019/8524607] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/17/2018] [Accepted: 01/14/2019] [Indexed: 12/11/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited progressive retinal dystrophies that is present with progressive vision loss, night blindness, visual field reduction, and retinal pigmentation of the fundus. RP is an uncommon but clinically important disease. It is progressive and potentially blinding, and to date, no cure for RP has been identified and clinical interventions to retard disease progression are limited. Because of the nature of this disease, there has been great interest in the development of therapeutic interventions that may prevent its progression or restore the loss of visual function. Studies have indicated a possible role of vitamins and minerals in preventing the progression of RP: vitamin A has been reported to have an important role in the function of retinal photoreceptors; lutein is assumed to play a preventive role in fundus diseases; and docosahexaenoic acid, which is found within photoreceptor cell membranes, may have a functional role in preventing the progression of RP. Therefore, this study aimed to systematically review data from randomized clinical trials (RCTs) evaluating the safety and efficacy of vitamins and mineral supplements for the treatment of RP. We searched through relevant trials in the Cochrane Library, PubMed, Embase, Ovid, AMED, OpenGrey, ISRCTN registry, http://ClinicalTrials.gov, and the WHO ICTRP ranging from the respective dates of foundation to June 18, 2018. We reviewed eight randomized control trials (RCTs) with data for 1231 patients. The results indicated that patients with RP may experience delayed disease progression with vitamin and mineral supplementation. In a broader sense, this review suggests that the future trials on RP patients should consider more vitamins or mineral supplements and other outcome measures from the trials included in this review.
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Cicinelli MV, Battista M, Starace V, Battaglia Parodi M, Bandello F. Monitoring and Management of the Patient with Stargardt Disease. CLINICAL OPTOMETRY 2019; 11:151-165. [PMID: 31819694 PMCID: PMC6886536 DOI: 10.2147/opto.s226595] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/16/2019] [Indexed: 05/10/2023]
Abstract
Stargardt disease (STGD1) represents one of the major common causes of inherited irreversible visual loss. Due to its high phenotypic and genotypic heterogeneity, STGD1 is a complex disease to understand. Non-invasive imaging, biochemical, and genetic advances have led to substantial improvements in unveiling the disease processes and novel promising therapeutic landscapes have been proposed. This review recapitulates the modalities for monitoring patients with STGD1 and the therapeutic options currently under investigation for the different stages of the disease.
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Affiliation(s)
- Maria Vittoria Cicinelli
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
- Correspondence: Maria Vittoria Cicinelli Department of Ophthalmology, San Raffaele Vita-Salute University, Via Olgettina, 60, Milano20132, ItalyTel +39 02 26432648Fax +39 02 26483643 Email
| | - Marco Battista
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Vincenzo Starace
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | | | - Francesco Bandello
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
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McClements ME, Barnard AR, Singh MS, Charbel Issa P, Jiang Z, Radu RA, MacLaren RE. An AAV Dual Vector Strategy Ameliorates the Stargardt Phenotype in Adult Abca4-/- Mice. Hum Gene Ther 2018; 30:590-600. [PMID: 30381971 DOI: 10.1089/hum.2018.156] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The recent approval in the United States of the first adeno-associated viral (AAV) vector for the treatment of an inherited retinal degeneration validates this approach for the treatment of many other diseases. A major limiting factor continues to be the size restriction of the AAV transgene at under 5 kb. Stargardt disease is the most prevalent form of recessively inherited blindness and is caused by mutations in ABCA4, the gene that codes for ATP-binding cassette transporter protein family member 4, which has a coding sequence length of 6.8 kb. Dual vector approaches increase the capacity of AAV gene therapy, but at the cost of substantially reduced levels of target protein, which may be insufficient to achieve a therapeutic effect. Here we show that the efficacy of recombination of dual vectors is dependent on the length of DNA overlap between two transgenes. With optimized recombination, full-length ABCA4 protein is expressed in the photoreceptor outer segments of Abca4-/- mice at levels sufficient to reduce bisretinoid formation and correct the autofluorescent phenotype. These observations support a dual vector approach in future clinical trials using AAV gene therapy to treat Stargardt disease.
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Affiliation(s)
- Michelle E McClements
- 1 Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Alun R Barnard
- 1 Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | | | - Peter Charbel Issa
- 1 Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,3 Oxford Eye Hospital, Oxford, United Kingdom
| | - Zhichun Jiang
- 4 Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Roxana A Radu
- 4 Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Robert E MacLaren
- 1 Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,3 Oxford Eye Hospital, Oxford, United Kingdom
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Lenis TL, Hu J, Ng SY, Jiang Z, Sarfare S, Lloyd MB, Esposito NJ, Samuel W, Jaworski C, Bok D, Finnemann SC, Radeke MJ, Redmond TM, Travis GH, Radu RA. Expression of ABCA4 in the retinal pigment epithelium and its implications for Stargardt macular degeneration. Proc Natl Acad Sci U S A 2018; 115:E11120-E11127. [PMID: 30397118 PMCID: PMC6255167 DOI: 10.1073/pnas.1802519115] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recessive Stargardt disease (STGD1) is an inherited blinding disorder caused by mutations in the Abca4 gene. ABCA4 is a flippase in photoreceptor outer segments (OS) that translocates retinaldehyde conjugated to phosphatidylethanolamine across OS disc membranes. Loss of ABCA4 in Abca4-/- mice and STGD1 patients causes buildup of lipofuscin in the retinal pigment epithelium (RPE) and degeneration of photoreceptors, leading to blindness. No effective treatment currently exists for STGD1. Here we show by several approaches that ABCA4 is additionally expressed in RPE cells. (i) By in situ hybridization analysis and by RNA-sequencing analysis, we show the Abca4 mRNA is expressed in human and mouse RPE cells. (ii) By quantitative immunoblotting, we show that the level of ABCA4 protein in homogenates of wild-type mouse RPE is about 1% of the level in neural retina homogenates. (iii) ABCA4 immunofluorescence is present in RPE cells of wild-type and Mertk-/- but not Abca4-/- mouse retina sections, where it colocalizes with endolysosomal proteins. To elucidate the role of ABCA4 in RPE cells, we generated a line of genetically modified mice that express ABCA4 in RPE cells but not in photoreceptors. Mice from this line on the Abca4-/- background showed partial rescue of photoreceptor degeneration and decreased lipofuscin accumulation compared with nontransgenic Abca4-/- mice. We propose that ABCA4 functions to recycle retinaldehyde released during proteolysis of rhodopsin in RPE endolysosomes following daily phagocytosis of distal photoreceptor OS. ABCA4 deficiency in the RPE may play a role in the pathogenesis of STGD1.
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Affiliation(s)
- Tamara L Lenis
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Jane Hu
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Sze Yin Ng
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Zhichun Jiang
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Shanta Sarfare
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Marcia B Lloyd
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | | | - William Samuel
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20814
| | - Cynthia Jaworski
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20814
| | - Dean Bok
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | | | - Monte J Radeke
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20814
| | - Gabriel H Travis
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Roxana A Radu
- Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095;
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Taubitz T, Tschulakow AV, Tikhonovich M, Illing B, Fang Y, Biesemeier A, Julien-Schraermeyer S, Schraermeyer U. Ultrastructural alterations in the retinal pigment epithelium and photoreceptors of a Stargardt patient and three Stargardt mouse models: indication for the central role of RPE melanin in oxidative stress. PeerJ 2018; 6:e5215. [PMID: 30038866 PMCID: PMC6054867 DOI: 10.7717/peerj.5215] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 06/19/2018] [Indexed: 12/18/2022] Open
Abstract
Background Stargardt disease (SD) is characterized by the accumulation of the age-pigment lipofuscin in the retinal pigment epithelium (RPE) and subsequent neuroretinal degeneration. The disease leads to vision loss early in life. Here, we investigate age-dependent ultrastructural changes in three SD mouse models: albino Abca4-/- and pigmented Abca4-/- and Abca4-/-.Rdh8-/- mice. Since we found indications for oxidative stress primarily in albino SD mice, we tested RPE melanin for its antioxidative capabilities. Methods SD mouse eyes were investigated by light, fluorescence and electron microscopy and were compared to the respective albino and pigmented wild type mice and to a human donor SD eye. To confirm the role of RPE melanin in scavenging oxidative stress, melanin from S. officinalis as a standard and porcine RPE were tested for their capability to quench superoxide anions. Results Histological alterations indicative of oxidative stress and/or lysosomal dysfunction were present in albino Abca4-/- and Abca4-/-.Rdh8-/- mice. Retinal damage, such as inner segment rupture and pyknotic or free photoreceptor nuclei in the subretinal space and RPE vacuolization were exclusively found in albino Abca4-/- mice. Shortened and disorganized photoreceptor outer segments and dead RPE cells were found in albino Abca4-/- and Abca4-/-.Rdh8-/- mice, with earlier onset in albino Abca4-/- mice. Undegraded phagosomes and lipofuscin accumulation were present in the RPE of all three SD strains, but numbers were highest in Abca4-/-.Rdh8-/- mice. Lipofuscin morphology differed between SD strains: (melano-)lipofuscin granules in pigmented Abca4-/- mice had a homogenous electron density and sharp demarcations, while lipofuscin in albino Abca4-/- mice had a flocculent electron density and often lacked a surrounding membrane, indicating loss of lysosomal integrity. Young Abca4-/-.Rdh8-/- mice showed (melano-)lipofuscin granules with homogenous electron density, while in aged animals granules with flocculent electron density predominated. Both strains of pigmented SD mice had melanolipofuscin clusters as found in the human SD eye. Like melanin from S. officinalis, porcine RPE melanin can also quench superoxide anions. Discussion The presented pathologies in albino Abca4-/- and Abca4-/-.Rdh8-/- mice suggest oxidative stress and/or lysosomal dysfunction within the RPE. Since albino Abca4-/- mice have the earliest onset and severest damage and as absence of melanin and also melanin turnover with age are known to diminish RPEs anti-oxidative properties, we assume that RPE melanin plays a role in SD related damages. A lack of pathology in pigmented Abca4-/- mice due to lower stress levels as compared to the Abca4-/-.Rdh8-/- mice underlines this hypothesis. It is also supported by the finding that RPE melanin can quench superoxide anions. We therefore suppose that RPE melanin is important in retinal health and we discuss its role as an oxidative stress scavenger.
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Affiliation(s)
- Tatjana Taubitz
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Alexander V Tschulakow
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Marina Tikhonovich
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Barbara Illing
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Yuan Fang
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Antje Biesemeier
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Sylvie Julien-Schraermeyer
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Ulrich Schraermeyer
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
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Federspiel CA, Bertelsen M, Kessel L. Vitamin A in Stargardt disease-an evidence-based update. Ophthalmic Genet 2018; 39:555-559. [PMID: 29939824 DOI: 10.1080/13816810.2018.1488174] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND High intake of vitamin A is suspected to be a risk factor for the progression of Stargardt disease (STGD1) and many health authorities recommend Stargardt patients not to use oral vitamin A supplements outside that provided naturally in the food. The present study provides the first systematic review of the current level of evidence regarding the role of supplementary vitamin A in STGD1. MATERIALS AND METHODS We conducted a systematic scientific literature search in the Pubmed database on studies reporting on the effect of oral vitamin A or serum retinol on visual function. RESULTS In animal studies neither high nor low serum retinol in an Abca4 knockout mouse model of Stargardt showed any effect on electroretinography (ERG). In humans, significantly better visual function was reported in a cross-sectional study of patients with a low dietary intake of vitamin A, whereas a prospective study did not find any correlation between vitamin A supplementation and visual acuity. A newly introduced vitamin A substitute (C20-D(3)-vitamin A) has shown promising effects on ERG in a Stargardt mouse model. CONCLUSIONS There are few studies on the effect of vitamin A in STGD1. The scarcity and inconclusiveness of evidence available impel further research efforts to reach a more confident conclusion. Currently, recommendations to avoid vitamin A dietary supplementation rely mainly on a theoretical background. Animal studies on vitamin A substitute as a possible therapeutic approach in preventing or slowing vision loss in STGD1 seems promising but further clinical trials are needed to verify the results.
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Affiliation(s)
| | - Mette Bertelsen
- b Department of Clinical Genetics , Rigshospitalet , Copenhagen , Denmark
| | - Line Kessel
- a Department of Ophthalmology , Rigshospitalet-Glostrup , Copenhagen , Denmark.,c Institute of Clinical Medicine, Faculty of Health Sciences , University of Copenhagen , Copenhagen , Denmark
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Bisretinoid Photodegradation Is Likely Not a Good Thing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1074:395-401. [PMID: 29721969 DOI: 10.1007/978-3-319-75402-4_49] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Retinaldehyde adducts (bisretinoids) accumulate in retinal pigment epithelial (RPE) cells as lipofuscin. Bisretinoids are implicated in some inherited and age-related forms of macular degeneration that lead to the death of RPE cells and diminished vision. By comparing albino and black-eyed mice and by rearing mice in darkness and in cyclic light, evidence indicates that bisretinoid fluorophores undergo photodegradation in the eye (Ueda et al. Proc Natl Acad Sci 113:6904-6909, 2016). Given that the photodegradation products modify and impair cellular and extracellular molecules, these processes likely impart cumulative damage to retina.
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Abstract
Cells are subject to metabolic sources of oxidizing species and to the need to regulate Fe, a redox-active metal. Retinal pigment epithelial (RPE) cells have to contend with an additional, unique source of oxidative stress: photooxidative insult from bisretinoids that accumulate as lipofuscin. Here we report that Fe can interact with bisretinoids in RPE to promote cell damage. These findings inform disease processes in both Fe-related and bisretinoid-associated retinal degeneration. The link between Fe and bisretinoid oxidation also highlights opportunities for repurposed and combination therapies. This could include visual cycle inhibitors as a treatment for maculopathy associated with elevated retinal Fe, and Fe chelation to aid in suppressing the damaging effects of bisretinoids in juvenile and age-related macular degeneration. Intracellular Fe plays a key role in redox active energy and electron transfer. We sought to understand how Fe levels impact the retina, given that retinal pigment epithelial (RPE) cells are also challenged by accumulations of vitamin A aldehyde adducts (bisretinoid lipofuscin) that photogenerate reactive oxygen species and photodecompose into damaging aldehyde- and dicarbonyl-bearing species. In mice treated with the Fe chelator deferiprone (DFP), intracellular Fe levels, as reflected in transferrin receptor mRNA expression, were reduced. DFP-treated albino Abca4−/− and agouti wild-type mice exhibited elevated bisretinoid levels as measured by high-performance liquid chromatography or noninvasively by quantitative fundus autofluorescence. Thinning of the outer nuclear layer, a parameter indicative of the loss of photoreceptor cell viability, was also reduced in DFP-treated albino Abca4−/−. In contrast to the effects of the Fe chelator, mice burdened with increased intracellular Fe in RPE due to deficiency in the Fe export proteins hephaestin and ceruloplasmin, presented with reduced bisretinoid levels. These findings indicate that intracellular Fe promotes bisretinoid oxidation and degradation. This interpretation was supported by experiments showing that DFP decreased the oxidative/degradation of the bisretinoid A2E in the presence of light and reduced cell death in cell-based experiments. Moreover, light-independent oxidation and degradation of A2E by Fenton chemistry products were evidenced by the consumption of A2E, release of dicarbonyls, and generation of oxidized A2E species in cell-free assays.
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Shin Y, Moiseyev G, Petrukhin K, Cioffi CL, Muthuraman P, Takahashi Y, Ma JX. A novel RPE65 inhibitor CU239 suppresses visual cycle and prevents retinal degeneration. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2420-2429. [PMID: 29684583 DOI: 10.1016/j.bbadis.2018.04.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/02/2018] [Accepted: 04/17/2018] [Indexed: 01/25/2023]
Abstract
The retinoid visual cycle is an ocular retinoid metabolism specifically dedicated to support vertebrate vision. The visual cycle serves not only to generate light-sensitive visual chromophore 11-cis-retinal, but also to clear toxic byproducts of normal visual cycle (i.e. all-trans-retinal and its condensation products) from the retina, ensuring both the visual function and the retinal health. Unfortunately, various conditions including genetic predisposition, environment and aging may attribute to a functional decline of the all-trans-retinal clearance. To combat all-trans-retinal mediated retinal degeneration, we sought to slow down the retinoid influx from the RPE by inhibiting the visual cycle with a small molecule. The present study describes identification of CU239, a novel non-retinoid inhibitor of RPE65, a key enzyme in the visual cycle. Our data demonstrated that CU239 selectively inhibited isomerase activity of RPE65, with IC50 of 6 μM. Further, our results indicated that CU239 inhibited RPE65 via competition with its substrate all-trans-retinyl ester. Mice with systemic injection of CU239 exhibited delayed chromophore regeneration after light bleach, and conferred a partial protection of the retina against injury from high intensity light. Taken together, CU239 is a potent visual cycle modulator and may have a therapeutic potential for retinal degeneration.
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Affiliation(s)
- Younghwa Shin
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - Gennadiy Moiseyev
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States.
| | - Konstantin Petrukhin
- Department of Ophthalmology, Columbia University, New York, NY 10032, United States
| | - Christopher L Cioffi
- Departments of Basic & Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, United States
| | - Parthasarathy Muthuraman
- Departments of Basic & Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, United States
| | - Yusuke Takahashi
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United states
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
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Huang XF. Current Pharmacological Concepts in the Treatment of the Retinitis Pigmentosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1074:439-445. [PMID: 29721974 DOI: 10.1007/978-3-319-75402-4_54] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) encompasses a heterogeneous group of inherited retinal disorders characterized by progressive photoreceptor and/or retinal pigment epithelial (RPE) degenerations with a prevalence approximately 1 in 4000 in the general population. Over 70 causative genes have been defined in RP families, and a number of animal models have been identified so far. However there have been no widely recognized treatments able to recover or reverse the degenerating retina, to prevent the disease deterioration, ultimately to restore the remaining vision. Therapeutics advancements have been achieved including gene therapy, pharmacotherapy, cell replacement, neurotrophic factors, and retinal prosthesis. In this review, we focus on the pharmaceutical drugs for RP with emphases on the context of drug discovery, development, and clinical translation.
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Affiliation(s)
- Xiu-Feng Huang
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China.
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