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Sonntag SR, Hamann M, Seifert E, Grisanti S, Brinkmann R, Miura Y. Detection sensitivity of fluorescence lifetime imaging ophthalmoscopy for laser-induced selective damage of retinal pigment epithelium. Graefes Arch Clin Exp Ophthalmol 2024:10.1007/s00417-024-06449-2. [PMID: 38587656 DOI: 10.1007/s00417-024-06449-2] [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: 11/05/2023] [Revised: 03/05/2024] [Accepted: 03/08/2024] [Indexed: 04/09/2024] Open
Abstract
PURPOSE To investigate the sensitivity of fluorescence lifetime imaging ophthalmoscopy (FLIO) to detect retinal laser spots by comparative analysis with other imaging modalities. METHODS A diode laser with a wavelength of 514 nm was applied with pulse durations of 5.2, 12, 20, and 50 µs. The laser pulse energy was increased so that the visibility of the laser spot by slit-lamp fundus examination (SL) under the irradiator's observation covers from the subvisible to visible range immediately after irradiation. The irradiated areas were then examined by fundus color photography (FC), optical coherence tomography (OCT), fundus autofluorescence (AF), FLIO, and fluorescein angiography (FA). The visibility of a total of over 2200 laser spots was evaluated by two independent researchers, and effective dose (ED) 50 laser pulse energy values were calculated for each imaging modality and compared. RESULTS Among examined modalities, FA showed the lowest mean of ED50 energy value and SL the highest, that is, they had the highest and lowest sensitivity to detect retinal pigment epithalium (RPE)-selective laser spots, respectively. FLIO also detected spots significantly more sensitively than SL at most laser pulse durations and was not significantly inferior to FA. AF was also often more sensitive than SL, but the difference was slightly less significant than FLIO. CONCLUSION Considering its high sensitivity in detecting laser spots and previously reported potential of indicating local wound healing and metabolic changes around laser spots, FLIO may be useful as a non-invasive monitoring tool during and after minimally invasive retinal laser treatment.
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Affiliation(s)
- Svenja Rebecca Sonntag
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Maximilian Hamann
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
| | | | - Salvatore Grisanti
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Ralf Brinkmann
- Medical Laser Center Lübeck, Lübeck, Germany
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Yoko Miura
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany.
- Medical Laser Center Lübeck, Lübeck, Germany.
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany.
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Dujardin C, Habeler W, Monville C, Letourneur D, Simon-Yarza T. Advances in the engineering of the outer blood-retina barrier: From in-vitro modelling to cellular therapy. Bioact Mater 2024; 31:151-177. [PMID: 37637086 PMCID: PMC10448242 DOI: 10.1016/j.bioactmat.2023.08.003] [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: 06/05/2023] [Revised: 07/13/2023] [Accepted: 08/06/2023] [Indexed: 08/29/2023] Open
Abstract
The outer blood-retina barrier (oBRB), crucial for the survival and the proper functioning of the overlying retinal layers, is disrupted in numerous diseases affecting the retina, leading to the loss of the photoreceptors and ultimately of vision. To study the oBRB and/or its degeneration, many in vitro oBRB models have been developed, notably to investigate potential therapeutic strategies against retinal diseases. Indeed, to this day, most of these pathologies are untreatable, especially once the first signs of degeneration are observed. To cure those patients, a current strategy is to cultivate in vitro a mature oBRB epithelium on a custom membrane that is further implanted to replace the damaged native tissue. After a description of the oBRB and the related diseases, this review presents an overview of the oBRB models, from the simplest to the most complex. Then, we propose a discussion over the used cell types, for their relevance to study or treat the oBRB. Models designed for in vitro applications are then examined, by paying particular attention to the design evolution in the last years, the development of pathological models and the benefits of co-culture models, including both the retinal pigment epithelium and the choroid. Lastly, this review focuses on the models developed for in vivo implantation, with special emphasis on the choice of the material, its processing and its characterization, before discussing the reported pre-clinical and clinical trials.
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Affiliation(s)
- Chloé Dujardin
- Université Paris Cité, Université Sorbonne Paris Nord, Laboratory for Vascular Translational Science (LVTS) INSERM-U1148, 75018 Paris, France
| | - Walter Habeler
- INSERM U861, I-Stem, AFM, Institute for Stem Cell Therapy and Exploration of Monogenic Diseases, 91100, Corbeil-Essonnes, France
- U861, I-Stem, AFM, Université Paris-Saclay, Université D’Evry, 91100, Corbeil-Essonnes, France
- CECS, Centre D’étude des Cellules Souches, 91100, Corbeil-Essonnes, France
| | - Christelle Monville
- INSERM U861, I-Stem, AFM, Institute for Stem Cell Therapy and Exploration of Monogenic Diseases, 91100, Corbeil-Essonnes, France
- U861, I-Stem, AFM, Université Paris-Saclay, Université D’Evry, 91100, Corbeil-Essonnes, France
| | - Didier Letourneur
- Université Paris Cité, Université Sorbonne Paris Nord, Laboratory for Vascular Translational Science (LVTS) INSERM-U1148, 75018 Paris, France
| | - Teresa Simon-Yarza
- Université Paris Cité, Université Sorbonne Paris Nord, Laboratory for Vascular Translational Science (LVTS) INSERM-U1148, 75018 Paris, France
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Rajanala K, Dotiwala F, Upadhyay A. Geographic atrophy: pathophysiology and current therapeutic strategies. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1327883. [PMID: 38983017 PMCID: PMC11182118 DOI: 10.3389/fopht.2023.1327883] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 11/22/2023] [Indexed: 07/11/2024]
Abstract
Geographic atrophy (GA) is an advanced stage of age-related macular degeneration (AMD) that leads to gradual and permanent vision loss. GA is characterized by the loss of photoreceptor cells and retinal pigment epithelium (RPE), leading to distinct atrophic patches in the macula, which tends to increase with time. Patients with geographic atrophy often experience a gradual and painless loss of central vision, resulting in difficulty reading, recognizing faces, or performing activities that require detailed vision. The primary risk factor for the development of geographic atrophy is advanced age; however, other risk factors, such as family history, smoking, and certain genetic variations, are also associated with AMD. Diagnosis is usually based on a comprehensive eye examination, including imaging tests such as fundus photography, optical coherence tomography (OCT), and fluorescein angiography. Numerous clinical trials are underway, targeting identified molecular pathways associated with GA that are promising. Recent approvals of Syfovre and Izervay by the FDA for the treatment of GA provide hope to affected patients. Administration of these drugs resulted in slowing the rate of progression of the disease. Though these products provide treatment benefits to the patients, they do not offer a cure for geographic atrophy and are limited in efficacy. Considering these safety concerns and limited treatment benefits, there is still a significant need for therapeutics with improved efficacy, safety profiles, and better patient compliance. This comprehensive review discusses pathophysiology, currently approved products, their limitations, and potential future treatment strategies for GA.
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Affiliation(s)
| | | | - Arun Upadhyay
- Research and Development, Ocugen Inc., Malvern, PA, United States
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4
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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] [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
- *Correspondence: Rose M. Gilbert,
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Murbach-Oliveira G, Banerjee K, Nociari MM, Thompson DH. Continuous Flow Synthesis of A2E Guided by Design of Experiments and High-Throughput Studies. ACS BIO & MED CHEM AU 2022; 2:297-306. [PMID: 37101569 PMCID: PMC10114832 DOI: 10.1021/acsbiomedchemau.1c00060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
N-Retinylidene-N-retinylethanolamine (A2E) is the most studied lipid bisretinoid. It forms lipofuscin deposits in the retinal pigment epithelium (RPE), causing vision impairment and blindness in eye conditions, such as Stargardt's disease, cone-rod dystrophy, Best's macular dystrophy, and potentially age-related macular degeneration. Synthetic A2E is often used for inducing the accumulation of lipofuscins within the lysosomes of RPE cells in culture as an in vitro surrogate of retinal lipofuscin buildup, providing insights into the mechanisms of these eye conditions. Many reports describing the use of synthetic A2E employ material that has been prepared using a one-pot reaction of all-trans-retinal (ATR) and ethanolamine at room temperature for 48 h. We have revisited this synthesis by performing a design of experiments (DoE) and high-throughput experimentation workflow that was tailored to identify the most productive combination of the variables (temperature, solvent, and reagent equivalences) for optimization of A2E yield. Our DoE findings revealed that the interaction of ethanolamine with acetic acid and ATR was pivotal for the formation of A2E in high yield, indicating that imine formation is the critical step in the reaction. Armed with these results, we were able to optimize the method using a microfluidic reactor system before upscaling those conditions for continuous flow synthesis of A2E. This revised method enabled a more efficient production of material, from a reaction time of 48 h to a residence time of 33 min, with an accompanying yield improvement from 49 to 78%. Furthermore, we implemented a simple method to evaluate the quality of the A2E produced using optical spectroscopy and LC-MS characteristics to assure that the biological properties observed with A2E samples are not confounded by the presence of oxidized impurities that are commonly present in conventional A2E samples.
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Affiliation(s)
- Giulia Murbach-Oliveira
- Department
of Chemistry, Multidisciplinary Cancer Research Facility, Purdue University, West Lafayette, Indiana 47907, United States
| | - Kalpita Banerjee
- Weil
Cornell Medical College, Ophthalmology Department, Dyson Research Institute, 1300 York Avenue, New York, New York 10065, United
States
| | - Marcelo M. Nociari
- Weil
Cornell Medical College, Ophthalmology Department, Dyson Research Institute, 1300 York Avenue, New York, New York 10065, United
States
| | - David H. Thompson
- Department
of Chemistry, Multidisciplinary Cancer Research Facility, Purdue University, West Lafayette, Indiana 47907, United States
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Zhang D, Robinson K, Washington I. C20D3-Vitamin A Prevents Retinal Pigment Epithelium Atrophic Changes in a Mouse Model. Transl Vis Sci Technol 2021; 10:8. [PMID: 34878528 PMCID: PMC8662574 DOI: 10.1167/tvst.10.14.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Purpose This study aimed to evaluate the contribution of vitamin A dimerization to retinal pigment epithelium (RPE) atrophic changes. Leading causes of irreversible blindness, including Stargardt disease and age-related macular degeneration (AMD), occur as a result of atrophic changes in RPE. The cause of the RPE atrophic changes is not apparent. During the vitamin A cycle, vitamin A dimerizes, leading to vitamin A cycle byproducts, such as vitamin A dimers, in the RPE. Methods To study the consequence of vitamin A dimerization to RPE atrophic changes, we used a rodent model with accelerated vitamin A dimerization, Abca4−/−/Rdh8−/− mice, and the vitamin A analog C20D3-vitamin A to selectively ameliorate the accelerated rate of vitamin A dimerization. Results We show that ameliorating the rate of vitamin A dimerization with C20D3-vitamin A mitigates pathological changes observed in the prodromal phase of the most prevalent retinal degenerative diseases, including fundus autofluorescence changes, dark adaptation delays, and signature RPE atrophic changes. Conclusions Data demonstrate that the dimerization of vitamin A during the vitamin A cycle is sufficient alone to cause the prerequisite RPE atrophic changes thought to be responsible for the leading causes of irreversible blindness and that correcting the dimerization rate with C20D3-vitamin A may be sufficient to prevent the RPE atrophic changes. Translational Relevance Preventing the dimerization of vitamin A with the vitamin A analog C20D3-vitamin A may be sufficient to alter the clinical course of the most prevalent forms of blindness, including Stargardt disease and age-related macular degeneration (AMD).
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Affiliation(s)
- Dan Zhang
- Columbia University Medical Center, Ophthalmology, New York, NY, USA
| | - Kiera Robinson
- Columbia University Medical Center, Ophthalmology, New York, NY, USA
| | - Ilyas Washington
- Columbia University Medical Center, Ophthalmology, New York, NY, USA.,biOOrg3.14, Buffalo, WY, USA
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7
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Zhang D, Mihai DM, Washington I. Vitamin A cycle byproducts explain retinal damage and molecular changes thought to initiate retinal degeneration. Biol Open 2021; 10:273577. [PMID: 34842275 PMCID: PMC8649638 DOI: 10.1242/bio.058600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 09/03/2021] [Indexed: 01/24/2023] Open
Abstract
In the most prevalent retinal diseases, including Stargardt disease and age-related macular degeneration (AMD), byproducts of vitamin A form in the retina abnormally during the vitamin A cycle. Despite evidence of their toxicity, whether these vitamin A cycle byproducts contribute to retinal disease, are symptoms, beneficial, or benign has been debated. We delivered a representative vitamin A byproduct, A2E, to the rat's retina and monitored electrophysiological, histological, proteomic, and transcriptomic changes. We show that the vitamin A cycle byproduct is sufficient alone to damage the RPE, photoreceptor inner and outer segments, and the outer plexiform layer, cause the formation of sub-retinal debris, alter transcription and protein synthesis, and diminish retinal function. The presented data are consistent with the theory that the formation of vitamin A byproducts during the vitamin A cycle is neither benign nor beneficial but may be sufficient alone to cause the most prevalent forms of retinal disease. Retarding the formation of vitamin A byproducts could potentially address the root cause of several retinal diseases to eliminate the threat of irreversible blindness for millions of people. Summary: During the vitamin A cycle, byproducts of vitamin A form in the eye. Using a rat model, we show that the byproducts alone can explain several retinal derangements observed in the prodromal phase of human retinal disease. Retarding the formation of these byproducts may address the root cause of the most prevalent retinal diseases.
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Affiliation(s)
- Dan Zhang
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Doina M Mihai
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Ilyas Washington
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA.,biOOrg3.14, Buffalo, WY 82834, USA
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8
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Modeling of Retinal Degeneration. Bull Exp Biol Med 2021; 171:286-291. [PMID: 34173098 DOI: 10.1007/s10517-021-05213-4] [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: 07/10/2020] [Indexed: 10/21/2022]
Abstract
We developed a model of retinal degeneration in rabbits based on exposure to light with a wavelength of 405 nm. This model allows reproducing structural and functional disorders in the central parts of the retina, including primarily degeneration of the outer layers of the retina (retinal pigment epithelium and layer of photoreceptor cells), and is designed to study the mechanisms of formation, progression and effectiveness of new drugs and methods of treatment of degenerative diseases of the retina.
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9
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A2E Distribution in RPE Granules in Human Eyes. Molecules 2020; 25:molecules25061413. [PMID: 32244898 PMCID: PMC7144568 DOI: 10.3390/molecules25061413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/11/2020] [Accepted: 03/17/2020] [Indexed: 12/30/2022] Open
Abstract
A2E (N-retinylidene-N-retinylethanolamine) is a major fluorophore in the RPE (retinal pigment epithelium). To identify and characterize A2E-rich RPE lipofuscin, we fractionated RPE granules from human donor eyes into five fractions (F1–F5 in ascending order of density) by discontinuous sucrose density gradient centrifugation. The dry weight of each fraction was measured and A2E was quantified by liquid chromatography/mass spectrometry (LC/MS) using a synthetic A2E homolog as a standard. Autofluorescence emission was characterized by a customer-built spectro-fluorometer system. A significant A2E level was detected in every fraction, and the highest level was found in F1, a low-density fraction that makes up half of the total weight of all RPE granules, contains 67% of all A2E, and emits 75% of projected autofluorescence by all RPE granules. This group of RPE granules, not described previously, is therefore the most abundant RPE lipofuscin granule population. A progressive decrease in autofluorescence was observed from F2 to F4, whereas no autofluorescence emission was detected from the heavily pigmented F5. The identification of a novel and major RPE lipofuscin population could have significant implications in our understanding of A2E and lipofuscin in human RPE.
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10
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Kotnala A, Senthilkumari S, Halder N, Kumar A, Velpandian T. Microwave assisted synthesis for A2E and development of LC-ESI-MS method for quantification of ocular bisretinoids in human retina. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1073:10-18. [PMID: 29232606 DOI: 10.1016/j.jchromb.2017.11.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 11/13/2017] [Accepted: 11/17/2017] [Indexed: 01/05/2023]
Abstract
PURPOSE To develop a microwave assisted method for the rapid synthesis of A2E and also to develop a method to quantify N-retinylidene-N-retinylethanolamine(A2E), all-trans retinal dimer (ATRD), A2-glycerophospho ethanolamine (A2GPE), dihydropyridine phosphatidyl ethanolamine (A2DHPE) and monofuran A2E (MFA2E) in age matched retina. METHODS The development of microwave assisted synthesis of A2E, its purification and characterization for its utility in quantification in human retina. The semi-quantitative method development using LC-ESI-MS, LC-ESI-MS/MS and LC-APCI-MS/MS from pooled macula and peripheral retina for the bisretinoid analysis has been done. RESULTS Maximum A2E conversion using microwave assisted process took place at 80°C for 45min with a yield of 55.01%. Highly sensitive and specific mass spectrometric method was developed using reverse phase C-18 separation with positive electrospray ionization and positive atmospheric phase chemical ionization of tandom mass spectrometry. A gradient mobile phase separation was achieved using water and methanol with 0.1% TFA. Multiple reaction monitoring acquisition for ESI and APCI was performed at ATRD m/z 551.2/522.2, A2GPE m/z 746.4/729.5, A2DHPEm/z 594.4/576.5, MFA2E m/z 608.2/591.2, A2E m/z 592.4/418.2. Method was validated using LC-ESI-SIM mode to determine selectivity, linearity, sensitivity, precision and accuracy. CONCLUSION An attempt towards optimization of the synthetic procedure of A2E was made so as to reduce the lengthy reaction time without compromising the yield. Developed method was capable enough for the detection of low level of bisretinids in retina.
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Affiliation(s)
- A Kotnala
- Ocular Pharmacology & Pharmacy Division, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - S Senthilkumari
- Department of Ocular Pharmacology, Aravind Medical Research Foundation, Madurai, Tamilnadu, India
| | - N Halder
- Ocular Pharmacology & Pharmacy Division, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - A Kumar
- Department of Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - T Velpandian
- Ocular Pharmacology & Pharmacy Division, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
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Layana AG, Minnella AM, Garhöfer G, Aslam T, Holz FG, Leys A, Silva R, Delcourt C, Souied E, Seddon JM. Vitamin D and Age-Related Macular Degeneration. Nutrients 2017; 9:nu9101120. [PMID: 29027953 PMCID: PMC5691736 DOI: 10.3390/nu9101120] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/03/2017] [Accepted: 10/06/2017] [Indexed: 12/12/2022] Open
Abstract
In recent years, the relationship between vitamin D and health has received growing attention from the scientific and medical communities. Vitamin D deficiencies have been repeatedly associated with various acute and chronic diseases, including age-related macular degeneration (AMD). Its active metabolite, 1α,25-dihydoxy vitamin D, acts as a modulator of cell proliferation, differentiation and apoptosis, and cumulative data from experimental and observational studies suggest that relatively a lower vitamin D status could be a potential risk factor for the development of early and/or late AMD. Herein, we made a narrative review of the mechanisms linking a potential role of vitamin D with the current concepts of AMD pathophysiology.
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Affiliation(s)
| | - Angelo Maria Minnella
- Dipartimento di Scienze Otorinolaringoiatriche e Oftalmologiche, Universita' Cattolica del Sacro Cuore, Lgo F. Vito 1, 00168 Roma, Italy.
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, University of Vienna, 1090 Vienna, Austria.
| | - Tariq Aslam
- School of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK.
- Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, M13 9WL Manchester, and Heriot Watt University, Edinburgh EH14 4AS, UK.
| | - Frank G Holz
- Department of Ophthalmology, University of Bonn, D-53107 Bonn, Germany.
| | - Anita Leys
- Department of Ophthalmology, University Hospitals Leuven, 3000 Leuven, Belgium.
| | - Rufino Silva
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, 3000-548 Coimbra, Portugal.
- Centro Hospitalar e Universitário de Coimbra (CHUC), Department of Ophthalmology, 3000-548 Coimbra, Portugal.
- Centro Hospitalar e Universitário de Coimbra (CHUC), Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences (IBILI-FMUC), University of Coimbra, 3000-548 Coimbra, Portugal.
- Centro Hospitalar e Universitário de Coimbra (CHUC), Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal.
| | - Cécile Delcourt
- University of Bordeaux, INSERM, Bordeaux Population Health Research Center, Team LEHA, UMR 1219, F-33000 Bordeaux, France.
| | - Eric Souied
- Hôpital Intercommunal de Créteil, University Paris Est, 94010 Créteil, France.
| | - Johanna M Seddon
- Department of Ophthalmology, Tufts University School of Medicine, Boston, MA 02111, USA.
- Ophthalmic Epidemiology and Genetics Service, Tufts Medical Center, Boston, MA 02111, USA.
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12
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Xiao J, Yao J, Jia L, Lin C, Zacks DN. Protective Effect of Met12, a Small Peptide Inhibitor of Fas, on the Retinal Pigment Epithelium and Photoreceptor After Sodium Iodate Injury. Invest Ophthalmol Vis Sci 2017; 58:1801-1810. [PMID: 28346613 PMCID: PMC5374881 DOI: 10.1167/iovs.16-21392] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purpose A major problem in macular degeneration is the inability to reduce RPE and photoreceptor death. These cells die by necroptosis and apoptosis, respectively, but the upstream activator(s) of these death pathways is unknown. In this study, we use the sodium iodate (NaIO3) model of oxidative stress to test the hypothesis that activation of the Fas receptor contributes to the death of the RPE and photoreceptors. Methods Sodium iodate was injected in Brown-Norway rats via femoral vein injection. Both in vivo (fundus photography, optical coherence tomography, and fluorescein angiography) and ex vivo (histology, immunohistochemistry, Western blot, and RT-PCR) analyses of the RPE and retina were conducted at baseline, as well as at various times post NaIO3 injection. The ability of intravitreal injection of Met12, a small peptide inhibitor of the Fas receptor, to prevent RPE and photoreceptor cell death was assessed. Results Injection of NaIO3 led to Fas-mediated activation of both necroptosis and apoptosis in the RPE and photoreceptors, respectively. This was accompanied by a significant increase in the number of microglia/macrophages in the outer retina. Met12 significantly reduced the activation of the Fas-mediated death pathways, resulting in reduced RPE and photoreceptor death and a decreased immune response. Conclusions Our results demonstrate that NaIO3 activates Fas-mediated cell death, both in the RPE and photoreceptor, and that a small peptide antagonist of the Fas receptor, Met12, significantly reduces the extent of this cell death. These findings suggest a role for Fas inhibition to protect the RPE and photoreceptors from death due to oxidative stress.
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Affiliation(s)
- Jianhui Xiao
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan, United States 2Department of Ophthalmology, Sun Yat-Sen Memorial Hospital, Guangzhou, China
| | - Jingyu Yao
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - Chengmao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan, United States
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan, United States
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Fontaine V, Monteiro E, Brazhnikova E, Lesage L, Balducci C, Guibout L, Feraille L, Elena PP, Sahel JA, Veillet S, Lafont R. Norbixin Protects Retinal Pigmented Epithelium Cells and Photoreceptors against A2E-Mediated Phototoxicity In Vitro and In Vivo. PLoS One 2016; 11:e0167793. [PMID: 27992460 PMCID: PMC5161507 DOI: 10.1371/journal.pone.0167793] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 11/20/2016] [Indexed: 12/31/2022] Open
Abstract
The accumulation of N-retinylidene-N-retinylethanolamine (A2E, a toxic by-product of the visual pigment cycle) in the retinal pigment epithelium (RPE) is a major cause of visual impairment in the elderly. Photooxidation of A2E results in retinal pigment epithelium degeneration followed by that of associated photoreceptors. Present treatments rely on nutrient supplementation with antioxidants. 9’-cis-Norbixin (a natural diapocarotenoid, 97% purity) was prepared from Bixa orellana seeds. It was first evaluated in primary cultures of porcine retinal pigment epithelium cells challenged with A2E and illuminated with blue light, and it provided an improved photo-protection as compared with lutein or zeaxanthin. In Abca4-/-Rdh8-/- mice (a model of dry AMD), intravitreally-injected norbixin maintained the electroretinogram and protected photoreceptors against light damage. In a standard rat blue-light model of photodamage, norbixin was at least equally as active as phenyl-N-tert-butylnitrone, a free radical spin-trap. Chronic experiments performed with Abca4-/-Rdh8-/- mice treated orally for 3 months with norbixin showed a reduced A2E accumulation in the retina. Norbixin appears promising for developing an oral treatment of macular degeneration. A drug candidate (BIO201) with 9’-cis-norbixin as the active principle ingredient is under development, and its potential will be assessed in a forthcoming clinical trial.
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Affiliation(s)
- Valérie Fontaine
- Sorbonne Universités, UPMC Univ Paris, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, Paris, France
- * E-mail:
| | - Elodie Monteiro
- Sorbonne Universités, UPMC Univ Paris, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, Paris, France
| | - Elena Brazhnikova
- Sorbonne Universités, UPMC Univ Paris, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, Paris, France
| | - Laëtitia Lesage
- Sorbonne Universités, UPMC Univ Paris, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, Paris, France
| | - Christine Balducci
- Biophytis, Parc BIOCITECH, 102 Avenue Gaston Roussel, Romainville, France
| | - Louis Guibout
- Biophytis, Parc BIOCITECH, 102 Avenue Gaston Roussel, Romainville, France
| | | | | | - José-Alain Sahel
- Sorbonne Universités, UPMC Univ Paris, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, Paris, France
| | - Stanislas Veillet
- Biophytis, Parc BIOCITECH, 102 Avenue Gaston Roussel, Romainville, France
| | - René Lafont
- Biophytis, Parc BIOCITECH, 102 Avenue Gaston Roussel, Romainville, France
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14
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Washington I, Saad L. The Rate of Vitamin A Dimerization in Lipofuscinogenesis, Fundus Autofluorescence, Retinal Senescence and Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:347-53. [PMID: 26427431 DOI: 10.1007/978-3-319-17121-0_46] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
One of the earliest events preceding several forms of retinal degeneration is the formation and accumulation of vitamin A dimers in the retinal pigment epithelium (RPE) and underlying Bruch's membrane (BM). Such degenerations include Stargardt disease, Best disease, forms of retinitis pigmentosa, and age-related macular degeneration (AMD). Since their discovery in the 1990's, dimers of vitamin A, have been postulated as chemical triggers driving retinal senescence and degeneration. There is evidence to suggest that the rate at which vitamin A dimerizes and the eye's response to the dimerization products may dictate the retina's lifespan. Here, we present outstanding questions, finding the answers to which may help to elucidate the role of vitamin A dimerization in retinal degeneration.
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Affiliation(s)
- Ilyas Washington
- Department of Ophthalmology, Columbia University Medical Center, 160 Fort Washington Ave, Eye Research, 10032, New York, NY, USA.
| | - Leonide Saad
- Alkeus Pharmaceuticals, Inc., 02210, Boston, MA, USA.
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15
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Rescue of the Stargardt phenotype in Abca4 knockout mice through inhibition of vitamin A dimerization. Proc Natl Acad Sci U S A 2015; 112:8415-20. [PMID: 26106163 DOI: 10.1073/pnas.1506960112] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Stargardt disease, an ATP-binding cassette, subfamily A, member 4 (ABCA4)-related retinopathy, is a genetic condition characterized by the accelerated accumulation of lipofuscin in the retinal pigment epithelium, degeneration of the neuroretina, and loss of vision. No approved treatment exists. Here, using a murine model of Stargardt disease, we show that the propensity of vitamin A to dimerize is responsible for triggering the formation of the majority of lipofuscin and transcriptional dysregulation of genes associated with inflammation. Data further demonstrate that replacing vitamin A with vitamin A deuterated at the carbon 20 position (C20-D3-vitamin A) impedes the dimerization rate of vitamin A--by approximately fivefold for the vitamin A dimer A2E--and subsequent lipofuscinogenesis and normalizes the aberrant transcription of complement genes without impairing retinal function. Phenotypic rescue by C20-D3-vitamin A was also observed noninvasively by quantitative autofluorescence, an imaging technique used clinically, in as little as 3 months after the initiation of treatment, whereas upon interruption of treatment, the age-related increase in autofluorescence resumed. Data suggest that C20-D3-vitamin A is a clinically amiable tool to inhibit vitamin A dimerization, which can be used to determine whether slowing the dimerization of vitamin A can prevent vision loss caused by Stargardt disease and other retinopathies associated with the accumulation of lipofuscin in the retina.
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