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Korbelik M, Heger M, Girotti AW. Participation of lipids in the tumor response to photodynamic therapy and its exploitation for therapeutic gain. J Lipid Res 2025; 66:100729. [PMID: 39675508 PMCID: PMC11911859 DOI: 10.1016/j.jlr.2024.100729] [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: 04/22/2024] [Revised: 11/19/2024] [Accepted: 12/06/2024] [Indexed: 12/17/2024] Open
Abstract
Hydroperoxides of unsaturated membrane lipids (LOOHs) are the most abundant non-radical intermediates generated by photodynamic therapy (PDT) of soft tissues such as tumors and have far longer average lifetimes than singlet oxygen or oxygen radicals formed during initial photodynamic action. LOOH-initiated post-irradiation damage to remaining membrane lipids (chain peroxidation) or to membrane-associated proteins remains largely unrecognized. Such after-light processes could occur during clinical oncological PDT, but this is not well-perceived by practitioners of this therapy. In general, the pivotal influence of lipids in tumor responses to PDT needs to be better appreciated. Of related importance is the fact that most malignant tumors have dramatically different lipid metabolism compared with healthy tissues, and this too is often ignored. The response of tumors to PDT appears especially vulnerable to manipulations within the tumor lipid microenvironment. This can be exploited for therapeutic gain with PDT, as exemplified here by the combined treatment with the antitumor lipid edelfosine.
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Affiliation(s)
- Mladen Korbelik
- Department of Integrative Oncology, BC Cancer, Vancouver, BC, Canada
| | - Michal Heger
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, Department of Pharmaceutics, College of Medicine, Jiaxing University, Jiaxing, Zhejiang, P. R. China; Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands; Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands.
| | - Albert W Girotti
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
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Cai J, Liao F, Mao Y, Liu S, Wu X, Tang S, Wang S, Shan G, Wu S. Regulation of LAMTOR1 by oxidative stress in retinal pigment epithelium: Implications for age-related macular degeneration pathogenesis. Exp Eye Res 2024; 249:110129. [PMID: 39424220 DOI: 10.1016/j.exer.2024.110129] [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: 07/29/2024] [Revised: 09/23/2024] [Accepted: 10/15/2024] [Indexed: 10/21/2024]
Abstract
Oxidative stress is a critical pathogenic factor for age-related macular degeneration (AMD). Autophagy serves as a mechanism to counteract oxidative stress. LAMTOR1 regulates mTORC1 activity by recruiting or disassembling it on the lysosome under the addition or deprivation of amino acids. This regulation inhibits or enhances autophagy. Our study investigates whether oxidative stress impacts LAMTOR1, thereby adapting to oxidative conditions. We employed oxidative stressors, menadione (VK3) and 4-hydroxynonenal (4-HNE), and observed a reduction of LAMTOR1 in both human and mouse retinal pigment epithelium (RPE) following short-term (1h) and prolonged exposures (24h). Nrf2 overexpression increased both lamtor1 mRNA and LAMTOR1 protein in the RPE. To determine if Nrf2 regulates lamtor1 transcription, we cloned the deletion mutants of the lamtor1 promoter into a luciferase reporter. Although the promoter contained antioxidant response elements, transcriptional activity depended on the interaction between Nrf2 and the constructs containing the transcriptional start site. Moreover, Nrf2-driven transcription was significantly reduced by an inhibitor of histone acetyltransferase, p300. Correspondingly, Nrf2 overexpression increased levels of acetylated histone 3 and p300. The reduction in LAMTOR1 by 4-HNE was reversed by pepstatin A and NH4Cl which block lysosomal degradation. 4-HNE increased TFEB nuclear translocation which was reversed by LAMTOR1 overexpression. In vivo, LAMTOR1 levels decreased in the photoreceptor and RPE layers of NaIO3-injected mice, compared to PBS-injected controls. In conclusion, oxidative injury reduces LAMTOR1, predominantly through lysosomal degradation although Nrf2-mediated histone acetylation enhances lamtor1 transcription. This study reveals a previously unrecognized regulatory mechanism of lamtor1 by oxidative stress, suggesting a novel role for LAMTOR1 in the pathogenesis of AMD.
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Affiliation(s)
- Jingjing Cai
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Fei Liao
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Yandie Mao
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Shuyi Liu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Xiong Wu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Shiqi Tang
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Simin Wang
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Ge Shan
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, 230027, China
| | - Shengzhou Wu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
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3
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Bakker LM, Boulton ME, Różanowska MB. (Photo)toxicity of Partially Oxidized Docosahexaenoate and Its Effect on the Formation of Lipofuscin in Cultured Human Retinal Pigment Epithelial Cells. Antioxidants (Basel) 2024; 13:1428. [PMID: 39594569 PMCID: PMC11591205 DOI: 10.3390/antiox13111428] [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: 10/10/2024] [Revised: 11/08/2024] [Accepted: 11/19/2024] [Indexed: 11/28/2024] Open
Abstract
Docosahexaenoate is a cytoprotective ω-3 polyunsaturated lipid that is abundant in the retina and is essential for its function. Due to its six unsaturated double bonds, docosahexaenoate is highly susceptible to oxidation and the formation of products with photosensitizing properties. This study aimed to test on cultured human retinal pigment epithelial cells ARPE-19 the (photo)cytotoxic potential of partly oxidized docosahexaenoate and its effect on the formation of lipofuscin from phagocytosed photoreceptor outer segments (POSs). The results demonstrate that the cytoprotective effects of docosahexaenoate do not counteract the deleterious effects of its oxidation products, leading to the concentration-dependent loss of cell metabolic activity, which is exacerbated by concomitant exposure to visible light. Partly oxidized docosahexaenoate does not cause permeability of the cell plasma membrane but does cause apoptosis. While vitamin E can provide partial protection from the (photo)toxicity of partly oxidized docosahexaenoate, zeaxanthin undergoes rapid photodegradation and can exacerbate the (photo)toxicity. Feeding cells with POSs enriched in partly oxidized docosahexaenoate results in a greater accumulation of intracellular fluorescent lipofuscin than in cells fed POSs without the addition. In conclusion, partly oxidized docosahexaenoate increases the accumulation of lipofuscin-like intracellular deposits, is cytotoxic, and its toxicity increases during exposure to light. These effects may contribute to the increased progression of geographic atrophy observed after long-term supplementation with docosahexaenoate in age-related macular degeneration patients.
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Affiliation(s)
- Linda M. Bakker
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, Wales, UK;
| | - Michael E. Boulton
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, Wales, UK;
- Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff CF10 3AX, Wales, UK
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4
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Geathers JS, Grillo SL, Karakoleva E, Campbell GP, Du Y, Chen H, Barber AJ, Zhao Y, Sundstrom JM. Sodium Iodate: Rapid and Clinically Relevant Model of AMD. FRONT BIOSCI-LANDMRK 2024; 29:380. [PMID: 39614439 DOI: 10.31083/j.fbl2911380] [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: 06/01/2024] [Revised: 08/21/2024] [Accepted: 08/27/2024] [Indexed: 12/01/2024]
Abstract
BACKGROUND Age-related macular degeneration (AMD) is the most common cause of vision loss in people above the age of 50, affecting approximately 10% of the population worldwide and the incidence is rising. Hyperreflective foci (HRF) are a major predictor of AMD progression. The purpose of this study was to use the sodium iodate mouse model to study HRF formation in retinal degeneration. METHODS Sodium iodate (NaIO3) treated rodents were studied to characterize HRF. 3-month-old male wild-type (WT) C57Bl/6J mice were injected with phosphate-buffered saline (PBS) or varying doses of NaIO3 (15-60 mg/kg). Optical Coherence Tomography (OCT) images were collected at baseline and several days post-NaIO3 injection. Retinal thicknesses were measured using Bioptigen software. Seven days post-injection, eyes were prepared for either transmission electron microscopy (TEM), Hematoxylin & Eosin (H&E), or immunofluorescence. RESULTS OCT imaging of the mice given higher doses of NaIO3 revealed HRF formation in the neural retina (n = 4). The amount of HRF correlated with the degree of retinal tissue loss. H&E and TEM imaging of the retinas seven days post-NaIO3 injection revealed several pigmented bodies in multiple layers of the retina (n = 3-5). Immunofluorescence revealed that some pigmented bodies were positive for macrophage markers and an epithelial-to-mesenchymal transition marker, while all were retinal pigment epithelium (RPE) 65-negative (n = 4). CONCLUSIONS The data suggest that NaIO3 induces the formation of HRF in the outer retina and their abundance correlates with retinal tissue loss. The experiments in this study highlight NaIO3 as a clinically relevant model of intermediate AMD that can be used to study HRF formation and to discover new treatment targets.
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Affiliation(s)
- Jasmine S Geathers
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Stephanie L Grillo
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Ema Karakoleva
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Gregory P Campbell
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Yixuan Du
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Han Chen
- Section of Research Resources, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Alistair J Barber
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Yuanjun Zhao
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Jeffrey M Sundstrom
- Department of Ophthalmology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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5
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Tang S, Yang J, Xiao B, Wang Y, Lei Y, Lai D, Qiu Q. Aberrant Lipid Metabolism and Complement Activation in Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2024; 65:20. [PMID: 39405051 PMCID: PMC11482642 DOI: 10.1167/iovs.65.12.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Accepted: 09/10/2024] [Indexed: 10/19/2024] Open
Abstract
Age-related macular degeneration (AMD) stands as a leading cause of severe visual impairment and blindness among the elderly globally. As a multifactorial disease, AMD's pathogenesis is influenced by genetic, environmental, and age-related factors, with lipid metabolism abnormalities and complement system dysregulation playing critical roles. This review delves into recent advancements in understanding the intricate interaction between these two crucial pathways, highlighting their contribution to the disease's progression through chronic inflammation, drusen formation, and retinal pigment epithelium dysfunction. Importantly, emerging evidence points to dysregulated lipid profiles, particularly alterations in high-density lipoprotein levels, oxidized lipid deposits, and intracellular lipofuscin accumulation, as exacerbating factors that enhance complement activation and subsequently amplify tissue damage in AMD. Furthermore, genetic studies have revealed significant associations between AMD and specific genes involved in lipid transport and complement regulation, shedding light on disease susceptibility and underlying mechanisms. The review further explores the clinical implications of these findings, advocating for a novel therapeutic approach that integrates lipid metabolism modulators with complement inhibitors. By concurrently targeting these pathways, the dual-targeted approach holds promise in significantly improving outcomes for AMD patients, heralding a new horizon in AMD management and treatment.
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Affiliation(s)
- Siao Tang
- Xiangya School of Medicine, Central South University, Changsha, Hunan, PR China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Jiaqi Yang
- Xiangya School of Medicine, Central South University, Changsha, Hunan, PR China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Bingqing Xiao
- Xiangya School of Medicine, Central South University, Changsha, Hunan, PR China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Yani Wang
- Xiangya School of Medicine, Central South University, Changsha, Hunan, PR China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Yiou Lei
- Xiangya School of Medicine, Central South University, Changsha, Hunan, PR China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Dongwei Lai
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, PR China
| | - Qinghua Qiu
- Department of Ophthalmology, Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
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6
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Bejarano E, Domenech-Bendaña A, Avila-Portillo N, Rowan S, Edirisinghe S, Taylor A. Glycative stress as a cause of macular degeneration. Prog Retin Eye Res 2024; 101:101260. [PMID: 38521386 PMCID: PMC11699537 DOI: 10.1016/j.preteyeres.2024.101260] [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: 01/05/2024] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 03/25/2024]
Abstract
People are living longer and rates of age-related diseases such as age-related macular degeneration (AMD) are accelerating, placing enormous burdens on patients and health care systems. The quality of carbohydrate foods consumed by an individual impacts health. The glycemic index (GI) is a kinetic measure of the rate at which glucose arrives in the blood stream after consuming various carbohydrates. Consuming diets that favor slowly digested carbohydrates releases sugar into the bloodstream gradually after consuming a meal (low glycemic index). This is associated with reduced risk for major age-related diseases including AMD, cardiovascular disease, and diabetes. In comparison, consuming the same amounts of different carbohydrates in higher GI diets, releases glucose into the blood rapidly, causing glycative stress as well as accumulation of advanced glycation end products (AGEs). Such AGEs are cytotoxic by virtue of their forming abnormal proteins and protein aggregates, as well as inhibiting proteolytic and other protective pathways that might otherwise selectively recognize and remove toxic species. Using in vitro and animal models of glycative stress, we observed that consuming higher GI diets perturbs metabolism and the microbiome, resulting in a shift to more lipid-rich metabolomic profiles. Interactions between aging, diet, eye phenotypes and physiology were observed. A large body of laboratory animal and human clinical epidemiologic data indicates that consuming lower GI diets, or lower glycemia diets, is protective against features of early AMD (AMDf) in mice and AMD prevalence or AMD progression in humans. Drugs may be optimized to diminish the ravages of higher glycemic diets. Human trials are indicated to determine if AMD progression can be retarded using lower GI diets. Here we summarized the current knowledge regarding the pathological role of glycative stress in retinal dysfunction and how dietary strategies might diminish retinal disease.
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Affiliation(s)
- Eloy Bejarano
- Department of Biomedical Sciences, School of Health Sciences and Veterinary School, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain
| | - Alicia Domenech-Bendaña
- Department of Biomedical Sciences, School of Health Sciences and Veterinary School, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain
| | | | - Sheldon Rowan
- JM USDA Human Nutrition Research Center on Aging at Tufts University, United States
| | - Sachini Edirisinghe
- Tufts University Friedman School of Nutrition Science and Policy, United States
| | - Allen Taylor
- Tufts University Friedman School of Nutrition Science and Policy, United States.
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7
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Basyal D, Lee S, Kim HJ. Antioxidants and Mechanistic Insights for Managing Dry Age-Related Macular Degeneration. Antioxidants (Basel) 2024; 13:568. [PMID: 38790673 PMCID: PMC11117704 DOI: 10.3390/antiox13050568] [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: 03/18/2024] [Revised: 04/26/2024] [Accepted: 05/02/2024] [Indexed: 05/26/2024] Open
Abstract
Age-related macular degeneration (AMD) severely affects central vision due to progressive macular degeneration and its staggering prevalence is rising globally, especially in the elderly population above 55 years. Increased oxidative stress with aging is considered an important contributor to AMD pathogenesis despite multifaceted risk factors including genetic predisposition and environmental agents. Wet AMD can be managed with routine intra-vitreal injection of angiogenesis inhibitors, but no satisfactory medicine has been approved for the successful management of the dry form. The toxic carbonyls due to photo-oxidative degradation of accumulated bisretinoids within lysosomes initiate a series of events including protein adduct formation, impaired autophagy flux, complement activation, and chronic inflammation, which is implicated in dry AMD. Therapy based on antioxidants has been extensively studied for its promising effect in reducing the impact of oxidative stress. This paper reviews the dry AMD pathogenesis, delineates the effectiveness of dietary and nutrition supplements in clinical studies, and explores pre-clinical studies of antioxidant molecules, extracts, and formulations with their mechanistic insights.
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Affiliation(s)
| | | | - Hye Jin Kim
- College of Pharmacy, Keimyung University, Dauge 42601, Republic of Korea
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8
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Korhonen E. Inflammasome activation in response to aberrations of cellular homeostasis in epithelial cells from human cornea and retina. Acta Ophthalmol 2024; 102 Suppl 281:3-68. [PMID: 38386419 DOI: 10.1111/aos.16646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Accepted: 01/16/2024] [Indexed: 02/24/2024]
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9
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Rozanowska M, Edge R, Land EJ, Navaratnam S, Sarna T, Truscott TG. Scavenging of Cation Radicals of the Visual Cycle Retinoids by Lutein, Zeaxanthin, Taurine, and Melanin. Int J Mol Sci 2023; 25:506. [PMID: 38203675 PMCID: PMC10779001 DOI: 10.3390/ijms25010506] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/26/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
In the retina, retinoids involved in vision are under constant threat of oxidation, and their oxidation products exhibit deleterious properties. Using pulse radiolysis, this study determined that the bimolecular rate constants of scavenging cation radicals of retinoids by taurine are smaller than 2 × 107 M-1s-1 whereas lutein scavenges cation radicals of all three retinoids with the bimolecular rate constants approach the diffusion-controlled limits, while zeaxanthin is only 1.4-1.6-fold less effective. Despite that lutein exhibits greater scavenging rate constants of retinoid cation radicals than other antioxidants, the greater concentrations of ascorbate in the retina suggest that ascorbate may be the main protectant of all visual cycle retinoids from oxidative degradation, while α-tocopherol may play a substantial role in the protection of retinaldehyde but is relatively inefficient in the protection of retinol or retinyl palmitate. While the protection of retinoids by lutein and zeaxanthin appears inefficient in the retinal periphery, it can be quite substantial in the macula. Although the determined rate constants of scavenging the cation radicals of retinol and retinaldehyde by dopa-melanin are relatively small, the high concentration of melanin in the RPE melanosomes suggests they can be scavenged if they are in proximity to melanin-containing pigment granules.
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Affiliation(s)
- Malgorzata Rozanowska
- Cardiff Institute of Tissue Engineering and Repair, Cardiff University, Cardiff CF10 3AX, UK
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK
| | - Ruth Edge
- Dalton Cumbrian Facility, The University of Manchester, Westlakes Science Park, Moor Row, Cumbria CA24 3HA, UK;
| | - Edward J. Land
- The Paterson Institute, The University of Manchester, Wilmslow Road, Manchester M20 4BX, UK;
| | - Suppiah Navaratnam
- Biomedical Sciences Research Institute, University of Salford, Manchester M5 4WT, UK;
| | - Tadeusz Sarna
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland;
| | - T. George Truscott
- School of Chemical and Physical Sciences, Lennard-Jones Building, Keele University, Staffordshire ST5 5BG, UK;
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10
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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: 1.0] [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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11
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Moir J, Hyman MJ, Wang J, Shah A, Maatouk C, Flores A, Skondra D. Associations Between Autoimmune Disease and the Development of Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2023; 64:45. [PMID: 38153747 PMCID: PMC10756244 DOI: 10.1167/iovs.64.15.45] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 12/05/2023] [Indexed: 12/29/2023] Open
Abstract
Purpose The pathogenesis of age-related macular degeneration (AMD) likely implicates the dysregulation of immune response pathways. Several studies demonstrate that the pathogenic elements of AMD resemble those of autoimmune diseases, yet the association between AMD development and most autoimmune diseases remain unexplored. Methods We conducted a case-control analysis of patients ages 55 and older with new-onset International Classification of Diseases (ICD) coding of dry, wet, or unspecified AMD between 2005 and 2019 in the Merative MarketScan Commercial and Medicare Databases. The diagnosis of an autoimmune disease was defined by an outpatient or inpatient claim with a relevant ICD code in the 12 months before the index visit. Conditional multivariable logistic regression, adjusted for AMD risk factors, was used to calculate odd ratios and 95% confidence intervals. Results We identified 415,027 cases with new-onset ICD coding for AMD matched with propensity scores to 414,853 controls. In total, 16.1% of cases and 15.9% of controls were diagnosed with any autoimmune disease. The diagnosis of any autoimmune disease did not affect the odds of new-onset ICD coding for AMD in multivariable regression (OR = 1.01; 95% CI, 0.999-1.02). Discoid lupus erythematosus (OR = 1.29; 95% CI, 1.12-1.48), systemic lupus erythematosus (SLE) (OR = 1.21; 95% CI, 1.15-1.27), giant cell arteritis (OR = 1.19; 95% CI, 1.09-1.30), Sjogren's syndrome (OR = 1.17; 95% CI, 1.09-1.26), and Crohn's disease (OR = 1.13; 95% CI, 1.06-1.22) increased the odds of a new-onset ICD coding for AMD. Conclusions Most autoimmune diseases do not affect the odds of developing AMD but several common autoimmune disorders such as SLE and Crohn's disease were associated with modestly increased odds of AMD. Further studies are needed to validate and investigate the underlying mechanisms of these associations.
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Affiliation(s)
- John Moir
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois, United States
| | - Max J. Hyman
- The Center for Health and the Social Sciences, University of Chicago, Chicago, Illinois, United States
| | - Jessie Wang
- Department of Ophthalmology and Visual Science, University of Chicago Medicine, Chicago, Illinois, United States
| | - Arjav Shah
- Department of Ophthalmology and Visual Science, University of Chicago Medicine, Chicago, Illinois, United States
| | - Christopher Maatouk
- Department of Ophthalmology and Visual Science, University of Chicago Medicine, Chicago, Illinois, United States
| | - Andrea Flores
- The Center for Health and the Social Sciences, University of Chicago, Chicago, Illinois, United States
| | - Dimitra Skondra
- Department of Ophthalmology and Visual Science, University of Chicago Medicine, Chicago, Illinois, United States
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12
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Linetsky M, Mondal A, Liu SY, Hite AM, Enduri S, Cheng YS, Feijo B, Kang G, Arhin N, Zeng H, Laniak OR, Denker J, Salomon RG. Cysteinyl leukotriene-like metabolites are generated in retinal pigment epithelial cells through glutathionylation/reduction of an oxidatively truncated fragment of arachidonate. RESULTS IN CHEMISTRY 2023; 6:100995. [PMID: 38855016 PMCID: PMC11160973 DOI: 10.1016/j.rechem.2023.100995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024] Open
Abstract
γ-Hydroxyalkenals, 4-hydroxynonenal (HNE) and phospholipid esters of 4-hydroxy-8-oxooctenoic acid (HOOA-PL), are produced from the alkyl and carboxyl termini of arachidonyl phospholipids by radical-induced oxidative cleavage. Metabolism of HNE by Michael addition of glutathione (GSH) followed by reduction of the aldehyde carbonyl produces a GSH derivative of 1,4-dihydroxynonane (DHN)-GSH. Analogous biochemistry was anticipated to produce a GSH derivative of 5,8-dihydroxyoctanoic acid (DHOA-GSH) that has structural and functional similarity to the cysteinyl leukotriene (LT)C4. We now report that exposure of human retinal pigment epithelial cells to CoCl2, an in vitro model of hypoxia-induced oxidative stress, generates DHOA-GSH and two products of its peptidolysis, DHOA-CysGly and DHOA-Cys that resemble LTD4 and LTE4. Identification of these metabolites was confirmed by unambiguous chemical syntheses that also provided a heavy isotope labeled quantitative standard 13C2 15N-DHOA-GSH. The availability of pure samples of these arachidonate metabolites will enable assessment of their biological activities, and testing the hypothesis that øLTs promote pathological inflammation by serving as LT receptor agonists. Because LT biosynthetic enzymes, e.g., 5-lipoxygenase, are not involved in the generation of øLTs in vivo, inhibitors of LT biosynthesis, e.g., Zileuton, are not expected to prevent the generation of øLTs. On the other hand, if øLTs are leukotriene receptor agonists, then the therapeutic effects of leukotriene receptor antagonist drugs, e.g., Montelukast, may include inhibition not only of LT-induced but also øLT-induced LT receptor activation and signaling.
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Affiliation(s)
- Mikhail Linetsky
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
- Department of Ophthalmology, Case Western Reserve University, Cleveland, OH 44106
| | - Anshula Mondal
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Si-Yang Liu
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Abby M Hite
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Shravani Enduri
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106
| | - Yu-Shiuan Cheng
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Beatriz Feijo
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106
| | - Graham Kang
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Nana Arhin
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Hong Zeng
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Olivia R Laniak
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
| | - John Denker
- Department of Ophthalmology, Case Western Reserve University, Cleveland, OH 44106
| | - Robert G Salomon
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
- Department of Ophthalmology, Case Western Reserve University, Cleveland, OH 44106
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13
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Neiteler A, Palakkan AA, Gallagher KM, Ross JA. Oxidative stress and docosahexaenoic acid injury lead to increased necroptosis and ferroptosis in retinal pigment epithelium. Sci Rep 2023; 13:21143. [PMID: 38036571 PMCID: PMC10689458 DOI: 10.1038/s41598-023-47721-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 11/17/2023] [Indexed: 12/02/2023] Open
Abstract
Age-related macular degeneration (AMD) is a complex disease caused by different genetic and environmental risk factors leading to loss of cells in the central part of the retina. Oxidative stress appears to be an important environmental risk factor that contributes to both the initiation and progression of AMD. Retinal pigment epithelium (RPE) plays an important role in regulating oxidative stress in the retina and is one of the main retinal cell types affected in AMD. A main function of RPE is to phagocytose photoreceptor outer segments (POS) which are rich in the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA), making this cell type potentially more susceptible to oxidative stress-induced lipid peroxidation which can lead to cell death. RPE is known to undergo necrotic cell death in response to oxidative stress. The aim of this study was to determine if DHA in POS can increase oxidative damage to RPE. It was found that RPE undergo increased lipid peroxidation and decreased cell viability when stressed with hydrogen peroxide in combination with DHA or POS. H2O2-induced oxidative stress was found to cause both ferroptosis and necroptosis. However, the ferroptosis regulator acyl-CoA synthetase long-chain family member 4 (ACSL4) was found to be downregulated in RPE exposed to H2O2 and this effect was exacerbated when the RPE cells were simultaneously treated with DHA. Together, these results show a response of RPE when stressed which will likely be overwhelmed under disease conditions such as AMD resulting in cell death.
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Affiliation(s)
- Almar Neiteler
- Tissue Injury and Repair Group, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
| | - Anwar A Palakkan
- Immunology and Stem Cell Biology, Aravind Medical Research Foundation, Anna Nagar, Madurai, 625020, India
| | - Kevin M Gallagher
- Tissue Injury and Repair Group, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - James A Ross
- Tissue Injury and Repair Group, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
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14
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Manikandan SK, Logan A, Cerrada-Gimenez M, Fitzhenry L, Coffey L, Kaja S, Rani S. Immune System, Inflammation and Autoantigens in Wet Age-Related Macular Degeneration: Pathological Significance and Therapeutic Importance. Life (Basel) 2023; 13:2236. [PMID: 38137838 PMCID: PMC10744676 DOI: 10.3390/life13122236] [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: 09/01/2023] [Revised: 11/06/2023] [Accepted: 11/13/2023] [Indexed: 12/24/2023] Open
Abstract
Wet age-related macular degeneration (wAMD) is a chronic inflammation-associated neurodegenerative disease affecting the posterior part of the eye in the aging population. Aging results in the reduced functionality of cells and tissues, including the cells of the retina. Initiators of a chronic inflammatory and pathologic state in wAMD may be a result of the accumulation of inevitable metabolic injuries associated with the maintenance of tissue homeostasis from a young age to over 50. Apart from this, risk factors like smoking, genetic predisposition, and failure to repair the injuries that occur, alongside attempts to rescue the hypoxic outer retina may also contribute to the pathogenesis. Aging of the immune system (immunosenescence) and a compromised outer blood retinal barrier (BRB) result in the exposure of the privileged milieu of the retina to the systemic immune system, further increasing the severity of the disease. When immune-privileged sites like the retina are under pathological stress, certain age- and disease-related conditions may necessitate assistance from cells distant from the resident ones to help restore the functionality of the tissue. As a necessary part of tissue repair, inflammation is a major response to disease and recruits immune cells to the site of damage. We suspect that the specific reparative inflammatory responses are controlled by an autoantigen-T cell-mediated mechanism, a process that may be hindered in wAMD.
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Affiliation(s)
- Sreeraj Kuruppilakath Manikandan
- Ocular Therapeutics Research Group, Pharmaceutical and Molecular Biotechnology Research Centre, South East Technological University, Waterford Campus, X91 K0EK Waterford, Ireland; (S.K.M.); (L.F.)
| | - Ann Logan
- Department of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7HL, UK;
| | | | - Laurence Fitzhenry
- Ocular Therapeutics Research Group, Pharmaceutical and Molecular Biotechnology Research Centre, South East Technological University, Waterford Campus, X91 K0EK Waterford, Ireland; (S.K.M.); (L.F.)
| | - Lee Coffey
- Ocular Therapeutics Research Group, Pharmaceutical and Molecular Biotechnology Research Centre, South East Technological University, Waterford Campus, X91 K0EK Waterford, Ireland; (S.K.M.); (L.F.)
| | - Simon Kaja
- Departments of Ophthalmology, Molecular Pharmacology & Neuroscience, Loyola University Chicago, Maywood, IL 60153, USA
| | - Sweta Rani
- Ocular Therapeutics Research Group, Pharmaceutical and Molecular Biotechnology Research Centre, South East Technological University, Waterford Campus, X91 K0EK Waterford, Ireland; (S.K.M.); (L.F.)
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15
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Liu M, Wu S, Wu Y, Zhang J, Chen J, Peng X, Yang Q, Tan Z, Zeng Z. Rubus suavissimus S. Lee Extract Alleviates Oxidative Stress and Inflammation in H 2O 2-Treated Retinal Pigment Epithelial Cells and in High-Fat Diet-Fed Mouse Retinas. FRONT BIOSCI-LANDMRK 2023; 28:279. [PMID: 38062823 DOI: 10.31083/j.fbl2811279] [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: 04/13/2023] [Revised: 07/15/2023] [Accepted: 07/20/2023] [Indexed: 12/18/2023]
Abstract
BACKGROUND Age-related macular degeneration (AMD) is the most common cause of visual disorders in the aged population and is characterized by the formation of retinal pigment epithelium (RPE) deposits and dysfunction/death of the RPE and photoreceptors. It is supposed that both oxidative stress and inflammation play a critical role in the pathogenesis of AMD. The development of therapeutic strategies against oxidative stress and inflammation in AMD is urgently needed. Rubus suavissimus S. Lee (RS), a medicinal plant growing in the southwest region of China, has been used as an herbal tea and medicine for various diseases. METHODS In this project, we evaluate the therapeutic potential of RS extract for AMD. We prepared RS extracts from dried leaves, which contained the main functional compounds. RESULTS RS extract significantly increased cell viability, upregulated the expression of antioxidant genes, lowered the generation of malondialdehyde and reactive oxygen species, and suppressed inflammation in H2O2-treated human RPE cells. In the in vivo study, treatment with RS extract attenuated body weight gain, lowered cholesterol and triglyceride levels in the liver and serum, increased antioxidant capacity, and alleviated inflammation in the retina and RPE/choroid of mice fed a high-fat diet. CONCLUSIONS Our findings suggest that RS extract offers therapeutic potential for treating AMD patients.
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Affiliation(s)
- Minzhuo Liu
- College of Biological and Chemical Engineering, Changsha University, 410022 Changsha, Hunan, China
| | - Shuiqing Wu
- Department of Urology, The Second Xiangya Hospital, Central South University, 410011 Changsha, Hunan, China
| | - Yi Wu
- College of Chinese Medicine, Hunan University of Chinese Medicine, 410208 Changsha, Hunan, China
| | - Jie Zhang
- College of Biological and Chemical Engineering, Changsha University, 410022 Changsha, Hunan, China
| | - Jun Chen
- College of Biological and Chemical Engineering, Changsha University, 410022 Changsha, Hunan, China
| | - Xucong Peng
- College of Biological and Chemical Engineering, Changsha University, 410022 Changsha, Hunan, China
| | - Qiusheng Yang
- College of Biological and Chemical Engineering, Changsha University, 410022 Changsha, Hunan, China
| | - Zhoujin Tan
- College of Chinese Medicine, Hunan University of Chinese Medicine, 410208 Changsha, Hunan, China
| | - Zhihong Zeng
- College of Biological and Chemical Engineering, Changsha University, 410022 Changsha, Hunan, China
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16
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Akhavanrezayat A, Khatri A, Onghanseng NGL, Halim MS, Or C, Sredar N, Razeen M, Hasanreisoglu M, Regenold J, Thng ZX, Mohammadi SS, Jain T, Yavari N, Bazojoo V, Gupta AS, Mobasserian A, Yasar C, Than NTT, Uludag Kirimli G, Karaca I, Shin YU, Yoo WS, Ghoraba H, Do DV, Dubra A, Nguyen QD. Structural and Functional Changes in Non-Paraneoplastic Autoimmune Retinopathy. Diagnostics (Basel) 2023; 13:3376. [PMID: 37958272 PMCID: PMC10649684 DOI: 10.3390/diagnostics13213376] [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: 09/27/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
BACKGROUND To describe longitudinal changes in patients with non-paraneoplastic autoimmune retinopathy (npAIR) by utilizing different diagnostic modalities/tests. METHODS The index study is a retrospective longitudinal review of sixteen eyes of eight patients from a tertiary care eye hospital diagnosed with npAIR. Multiple diagnostic modalities such as wide-angle fundus photography (WAFP), WA fundus autofluorescence (WAFAF), spectral-domain optical coherence tomography (SD-OCT), Goldmann visual field (GVF) perimetry, microperimetry (MP), electrophysiologic testing, and adaptive optics scanning laser ophthalmoscopy (AOSLO) were reviewed and analyzed. RESULTS At the baseline visits, anomalies were detected by multimodal diagnostic tests on all patients. Subjects were followed up for a median duration of 11.5 [3.0-18.7] months. Structural changes at the baseline were detected in 14 of 16 (87.5%) eyes on WAFP and WAFAF and 13 of 16 (81.2%) eyes on SD-OCT. Eight of the ten (80%) eyes that underwent AOSLO imaging depicted structural changes. Functional changes were detected in 14 of 16 (87.5%) eyes on GVF, 15 of 16 (93.7%) eyes on MP, and 11 of 16 (68.7%) eyes on full-field electroretinogram (ff-ERG). Multifocal electroretinogram (mf-ERG) and visual evoked potential (VEP) tests were performed in 14 eyes, of which 12 (85.7%) and 14 (100%) of the eyes demonstrated functional abnormalities, respectively, at baseline. Compared to all the other structural diagnostic tools, AOSLO had a better ability to demonstrate deterioration in retinal microstructures occurring at follow-ups. Functional deterioration at follow-up was detected on GVF in 8 of 10 (80%) eyes, mf-ERG in 4 of 8 (50%) eyes, and MP in 7 of 16 (43.7%) eyes. The ff-ERG and VEP were stable in the majority of cases at follow-up. CONCLUSIONS The utilization of multimodal imaging/tests in the diagnosing and monitoring of npAIR patients can aid in identifying anomalous changes over time. Analysis of both the anatomical and functional aspects by these devices can be supportive of detecting the changes early in such patients. AOSLO shows promise as it enables the capture of high-resolution images demonstrating quantifiable changes to retinal microstructure.
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Affiliation(s)
- Amir Akhavanrezayat
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Anadi Khatri
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- Birat Aankha Aspatal, Biratnagar 56613, Nepal
- Department of Ophthalmology, Birat Medical College and Teaching Hospital, Kathmandu University, Biratnagar 45200, Nepal
| | - Neil Gregory L. Onghanseng
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- Department of Ophthalmology, Makati Medical Center, Manila 1229, Philippines
| | - Muhammad Sohail Halim
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- Ocular Imaging Research and Reading Center, Sunnyvale, CA 94085, USA
| | - Christopher Or
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Nripun Sredar
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Moataz Razeen
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Murat Hasanreisoglu
- Department of Ophthalmology, Koc University School of Medicine, 34450 Istanbul, Turkey
- Koc University Research Center for Translational Medicine, Koc University, 34450 Istanbul, Turkey
| | - Jonathan Regenold
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Zheng Xian Thng
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore 308433, Singapore
| | - S. Saeed Mohammadi
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Tanya Jain
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- Dr. Shroff Charity Eye Hospital, New Delhi 110002, India
| | - Negin Yavari
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Vahid Bazojoo
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Ankur Sudhir Gupta
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Azadeh Mobasserian
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Cigdem Yasar
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Ngoc Trong Tuong Than
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Gunay Uludag Kirimli
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- Department of Ophthalmology, Duke University, Durham, NC 27705, USA
| | - Irmak Karaca
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Yong-Un Shin
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- Department of Ophthalmology, Hanyang University Guri Hospital, Hanyang University College of Medicine, Seoul 04763, Republic of Korea
| | - Woong-Sun Yoo
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
- Department of Ophthalmology, Gyeongsang National University College of Medicine, and Gyeongsang National University Hospital, Jinju 52727, Republic of Korea
| | - Hashem Ghoraba
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Diana V. Do
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Alfredo Dubra
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
| | - Quan Dong Nguyen
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA 94303, USA; (A.A.); (A.K.)
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17
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Swinkels D, Kocherlakota S, Das Y, Dane AD, Wever EJM, Vaz FM, Bazan NG, Van Veldhoven PP, Baes M. DHA Shortage Causes the Early Degeneration of Photoreceptors and RPE in Mice With Peroxisomal β-Oxidation Deficiency. Invest Ophthalmol Vis Sci 2023; 64:10. [PMID: 37934161 PMCID: PMC10631513 DOI: 10.1167/iovs.64.14.10] [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: 05/23/2023] [Accepted: 09/06/2023] [Indexed: 11/08/2023] Open
Abstract
Purpose Patients deficient in peroxisomal β-oxidation, which is essential for the synthesis of docosahexaenoic acid (DHA, C22:6n-3) and breakdown of very-long-chain polyunsaturated fatty acids (VLC-PUFAs), both important components of photoreceptor outer segments, develop retinopathy present with retinopathy. The representative mouse model lacking the central enzyme of this pathway, multifunctional protein 2 (Mfp2-/-), also show early-onset retinal decay and cell-autonomous retinal pigment epithelium (RPE) degeneration, accompanied by reduced plasma and retinal DHA levels. In this study, we investigated whether DHA supplementation can rescue the retinal degeneration of Mfp2-/- mice. Methods Mfp2+/- breeding pairs and their offspring were fed a 0.12% DHA or control diet during gestation and lactation and until sacrifice. Offspring were analyzed for retinal function via electroretinograms and for lipid composition of neural retina and plasma with lipidome analysis and gas chromatography, respectively, and histologically using retinal sections and RPE flatmounts at the ages of 4, 8, and 16 weeks. Results DHA supplementation to Mfp2-/- mice restored retinal DHA levels and prevented photoreceptor shortening, death, and impaired functioning until 8 weeks. In addition, rescue of retinal DHA levels temporarily improved the ability of the RPE to phagocytose outer segments and delayed the RPE dedifferentiation. However, despite the initial rescue of retinal integrity, DHA supplementation could not prevent retinal degeneration at 16 weeks. Conclusions We reveal that the shortage of a systemic supply of DHA is pivotal for the early retinal degeneration in Mfp2-/- mice. Furthermore, we report that adequate retinal DHA levels are essential not only for photoreceptors but also for RPE homeostasis.
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Affiliation(s)
- Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Sai Kocherlakota
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Yannick Das
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Adriaan D. Dane
- Department of Epidemiology and Data Science, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Eric J. M. Wever
- Department of Epidemiology and Data Science, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Frédéric M. Vaz
- Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Inborn Errors of Metabolism, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, The Netherlands
| | - Nicolas G. Bazan
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, Louisiana State University, New Orleans, Louisiana, United States
| | - Paul P. Van Veldhoven
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
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18
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Ferreira PA. Nucleocytoplasmic transport at the crossroads of proteostasis, neurodegeneration and neuroprotection. FEBS Lett 2023; 597:2567-2589. [PMID: 37597509 DOI: 10.1002/1873-3468.14722] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/21/2023]
Abstract
Nucleocytoplasmic transport comprises the multistep assembly, transport, and disassembly of protein and RNA cargoes entering and exiting nuclear pores. Accruing evidence supports that impairments to nucleocytoplasmic transport are a hallmark of neurodegenerative diseases. These impairments cause dysregulations in nucleocytoplasmic partitioning and proteostasis of nuclear transport receptors and client substrates that promote intracellular deposits - another hallmark of neurodegeneration. Disturbances in liquid-liquid phase separation (LLPS) between dense and dilute phases of biomolecules implicated in nucleocytoplasmic transport promote micrometer-scale coacervates, leading to proteinaceous aggregates. This Review provides historical and emerging principles of LLPS at the interface of nucleocytoplasmic transport, proteostasis, aging and noxious insults, whose dysregulations promote intracellular aggregates. E3 SUMO-protein ligase Ranbp2 constitutes the cytoplasmic filaments of nuclear pores, where it acts as a molecular hub for rate-limiting steps of nucleocytoplasmic transport. A vignette is provided on the roles of Ranbp2 in nucleocytoplasmic transport and at the intersection of proteostasis in the survival of photoreceptor and motor neurons under homeostatic and pathophysiological environments. Current unmet clinical needs are highlighted, including therapeutics aiming to manipulate aggregation-dissolution models of purported neurotoxicity in neurodegeneration.
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Affiliation(s)
- Paulo A Ferreira
- Department of Ophthalmology, Department of Pathology, Duke University Medical Center, NC, Durham, USA
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19
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Shome I, Thathapudi NC, Aramati BMR, Kowtharapu BS, Jangamreddy JR. Stages, pathogenesis, clinical management and advancements in therapies of age-related macular degeneration. Int Ophthalmol 2023; 43:3891-3909. [PMID: 37347455 DOI: 10.1007/s10792-023-02767-2] [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: 02/16/2022] [Accepted: 06/08/2023] [Indexed: 06/23/2023]
Abstract
Age-related macular degeneration (AMD) is a retinal degenerative disorder prevalent in the elderly population, which leads to the loss of central vision. The disease progression can be managed, if not prevented, either by blocking neovascularization ("wet" form of AMD) or by preserving retinal pigment epithelium and photoreceptor cells ("dry" form of AMD). Although current therapeutic modalities are moderately successful in delaying the progression and management of the disease, advances over the past years in regenerative medicine using iPSC, embryonic stem cells, advanced materials (including nanomaterials) and organ bio-printing show great prospects in restoring vision and efficient management of either forms of AMD. This review focuses on the molecular mechanism of the disease, model systems (both cellular and animal) used in studying AMD, the list of various regenerative therapies and the current treatments available. The article also highlights on the recent clinical trials using regenerative therapies and management of the disease.
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Affiliation(s)
- Ishita Shome
- UR Advanced Therapeutics Private Limited, ASPIRE-BioNest, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Neethi C Thathapudi
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada
- Department of Ophthalmology and Institute of Biomedical Engineering, Université de Montréal, Montréal, QC, Canada
| | - Bindu Madhav Reddy Aramati
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Bhavani S Kowtharapu
- UR Advanced Therapeutics Private Limited, ASPIRE-BioNest, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Jaganmohan R Jangamreddy
- UR Advanced Therapeutics Private Limited, ASPIRE-BioNest, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India.
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20
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Tong Y, Wu Y, Ma J, Ikeda M, Ide T, Griffin CT, Ding XQ, Wang S. Comparative mechanistic study of RPE cell death induced by different oxidative stresses. Redox Biol 2023; 65:102840. [PMID: 37566944 PMCID: PMC10440584 DOI: 10.1016/j.redox.2023.102840] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
Oxidative stress is hypothesized to drive the progression of age-related macular degeneration (AMD). Retinal pigment epithelial (RPE) cell layer is important for supporting the function of retina and is particularly susceptible to oxidative stress-induced cell death. How RPE cells die in AMD, especially in geographic atrophy (GA), a late stage of dry AMD, is still controversial. The goal of this study is to compare the features and mechanisms of RPE cell death induced by different oxidative stresses, to identify potential universal therapeutic targets for GA. RPE cell death was induced both in vitro and ex vivo by 4-Hydroxynonenal (4-HNE), a major product of lipid peroxidation, sodium iodate (NaIO3) that has been widely used to model RPE cell death in dry AMD, a ferroptosis inducer RAS-selective lethal 3 (RSL3) or a necroptosis inducer shikonin. We found that RPE necroptosis and ferroptosis show common and distinct features. Common features include receptor-interacting protein kinase (RIPK)1/RIPK3 activation and lipid reactive oxygen species (ROS) accumulation, although lipid ROS accumulation is much milder during necroptosis. This supports cross talk between RPE ferroptosis and necroptosis pathways and is consistent with the rescue of RPE necroptosis and ferroptosis by RIPK1 inhibitor Necrostatin-1 (Nec-1) or in Ripk3-/- RPE explants. Distinct feature includes activated mixed lineage kinase domain like pseudokinase (MLKL) that is translocated to the cell membrane during necroptosis, which is not happening in ferroptosis. This is consistent with the failure to rescue RPE ferroptosis by MLKL inhibitor necrosulfonamide (NSA) or in Mlkl-/- RPE explants. Using this framework, we found that 4-HNE and NaIO3 induced RPE cell death likely through necroptosis based on the molecular features and the rescuing effect by multiple inhibitors. Our studies suggest that multiple markers and inhibitors are required to distinguish RPE necroptosis and ferroptosis, and that necroptosis inhibitor Nec-1 could be a potential therapeutic compound for GA since it inhibits RIPK1/RIPK3 activation and lipid ROS accumulation occurred in both necroptosis and ferroptosis pathways.
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Affiliation(s)
- Yao Tong
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, 70118, USA
| | - Yinga Wu
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, 70118, USA
| | - Jing Ma
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, 70118, USA
| | - Masataka Ikeda
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tomomi Ide
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Courtney T Griffin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA; Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Xi-Qin Ding
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, 70118, USA; Department of Ophthalmology, Tulane University, New Orleans, LA, 70118, USA; Tulane Personalized Health Institute, Tulane University, New Orleans, LA, 70112, USA.
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21
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Kushwah N, Bora K, Maurya M, Pavlovich MC, Chen J. Oxidative Stress and Antioxidants in Age-Related Macular Degeneration. Antioxidants (Basel) 2023; 12:1379. [PMID: 37507918 PMCID: PMC10376043 DOI: 10.3390/antiox12071379] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
Oxidative stress plays a crucial role in aging-related eye diseases, including age-related macular degeneration (AMD), cataracts, and glaucoma. With age, antioxidant reparative capacity decreases, and excess levels of reactive oxygen species produce oxidative damage in many ocular cell types underling age-related pathologies. In AMD, loss of central vision in the elderly is caused primarily by retinal pigment epithelium (RPE) dysfunction and degeneration and/or choroidal neovascularization that trigger malfunction and loss of photo-sensing photoreceptor cells. Along with various genetic and environmental factors that contribute to AMD, aging and age-related oxidative damage have critical involvement in AMD pathogenesis. To this end, dietary intake of antioxidants is a proven way to scavenge free radicals and to prevent or slow AMD progression. This review focuses on AMD and highlights the pathogenic role of oxidative stress in AMD from both clinical and experimental studies. The beneficial roles of antioxidants and dietary micronutrients in AMD are also summarized.
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Affiliation(s)
| | | | | | | | - Jing Chen
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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22
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Zhang KR, Jankowski CSR, Marshall R, Nair R, Más Gómez N, Alnemri A, Liu Y, Erler E, Ferrante J, Song Y, Bell BA, Baumann BH, Sterling J, Anderson B, Foshe S, Roof J, Fazelinia H, Spruce LA, Chuang JZ, Sung CH, Dhingra A, Boesze-Battaglia K, Chavali VRM, Rabinowitz JD, Mitchell CH, Dunaief JL. Oxidative stress induces lysosomal membrane permeabilization and ceramide accumulation in retinal pigment epithelial cells. Dis Model Mech 2023; 16:dmm050066. [PMID: 37401371 PMCID: PMC10399446 DOI: 10.1242/dmm.050066] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 06/23/2023] [Indexed: 07/05/2023] Open
Abstract
Oxidative stress has been implicated in the pathogenesis of age-related macular degeneration, the leading cause of blindness in older adults, with retinal pigment epithelium (RPE) cells playing a key role. To better understand the cytotoxic mechanisms underlying oxidative stress, we used cell culture and mouse models of iron overload, as iron can catalyze reactive oxygen species formation in the RPE. Iron-loading of cultured induced pluripotent stem cell-derived RPE cells increased lysosomal abundance, impaired proteolysis and reduced the activity of a subset of lysosomal enzymes, including lysosomal acid lipase (LIPA) and acid sphingomyelinase (SMPD1). In a liver-specific Hepc (Hamp) knockout murine model of systemic iron overload, RPE cells accumulated lipid peroxidation adducts and lysosomes, developed progressive hypertrophy and underwent cell death. Proteomic and lipidomic analyses revealed accumulation of lysosomal proteins, ceramide biosynthetic enzymes and ceramides. The proteolytic enzyme cathepsin D (CTSD) had impaired maturation. A large proportion of lysosomes were galectin-3 (Lgals3) positive, suggesting cytotoxic lysosomal membrane permeabilization. Collectively, these results demonstrate that iron overload induces lysosomal accumulation and impairs lysosomal function, likely due to iron-induced lipid peroxides that can inhibit lysosomal enzymes.
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Affiliation(s)
- Kevin R. Zhang
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Connor S. R. Jankowski
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Rayna Marshall
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rohini Nair
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Néstor Más Gómez
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ahab Alnemri
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yingrui Liu
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elizabeth Erler
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Julia Ferrante
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ying Song
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brent A. Bell
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bailey H. Baumann
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jacob Sterling
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brandon Anderson
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sierra Foshe
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer Roof
- CHOP-PENN Proteomics Core Facility, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
| | - Hossein Fazelinia
- CHOP-PENN Proteomics Core Facility, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
| | - Lynn A. Spruce
- CHOP-PENN Proteomics Core Facility, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
| | - Jen-Zen Chuang
- Department of Ophthalmology, Weill Cornell Medicine, New York, NY 10065, USA
- Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Ching-Hwa Sung
- Department of Ophthalmology, Weill Cornell Medicine, New York, NY 10065, USA
- Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Venkata R. M. Chavali
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joshua D. Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Claire H. Mitchell
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joshua L. Dunaief
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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23
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Khan AH, Chowers I, Lotery AJ. Beyond the Complement Cascade: Insights into Systemic Immunosenescence and Inflammaging in Age-Related Macular Degeneration and Current Barriers to Treatment. Cells 2023; 12:1708. [PMID: 37443742 PMCID: PMC10340338 DOI: 10.3390/cells12131708] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/22/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
Landmark genetic studies have revealed the effect of complement biology and its regulation on the pathogenesis of age-related macular degeneration (AMD). Limited phase 3 clinical trial data showing a benefit of complement inhibition in AMD raises the prospect of more complex mediators at play. Substantial evidence supports the role of para-inflammation in maintaining homeostasis in the retina and choroid. With increasing age, a decline in immune system regulation, known as immunosenescence, has been shown to alter the equilibrium maintained by para-inflammation. The altered equilibrium results in chronic, sterile inflammation with aging, termed 'inflammaging', including in the retina and choroid. The chronic inflammatory state in AMD is complex, with contributions from cells of the innate and adaptive branches of the immune system, sometimes with overlapping features, and the interaction of their secretory products with retinal cells such as microglia and retinal pigment epithelium (RPE), extracellular matrix and choroidal vascular endothelial cells. In this review, the chronic inflammatory state in AMD will be explored by immune cell type, with a discussion of factors that will need to be overcome in the development of curative therapies.
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Affiliation(s)
- Adnan H. Khan
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, UK
- Southampton Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Itay Chowers
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
- Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91121, Israel
| | - Andrew J. Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, UK
- Southampton Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
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24
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Swinkels D, Baes M. The essential role of docosahexaenoic acid and its derivatives for retinal integrity. Pharmacol Ther 2023; 247:108440. [PMID: 37201739 DOI: 10.1016/j.pharmthera.2023.108440] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/08/2023] [Accepted: 05/15/2023] [Indexed: 05/20/2023]
Abstract
The fatty acid composition of photoreceptor outer segment (POS) phospholipids diverges from other membranes, being highly enriched in polyunsaturated fatty acids (PUFAs). The most abundant PUFA is docosahexaenoic acid (DHA, C22:6n-3), an omega-3 PUFA that amounts to over 50% of the POS phospholipid fatty acid side chains. Interestingly, DHA is the precursor of other bioactive lipids such as elongated PUFAs and oxygenated derivatives. In this review, we present the current view on metabolism, trafficking and function of DHA and very long chain polyunsaturated fatty acids (VLC-PUFAs) in the retina. New insights on pathological features generated from PUFA deficient mouse models with enzyme or transporter defects and corresponding patients are discussed. Not only the neural retina, but also abnormalities in the retinal pigment epithelium are considered. Furthermore, the potential involvement of PUFAs in more common retinal degeneration diseases such as diabetic retinopathy, retinitis pigmentosa and age-related macular degeneration are evaluated. Supplementation treatment strategies and their outcome are summarized.
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Affiliation(s)
- Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium.
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25
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Goodman D, Ness S. The Role of Oxidative Stress in the Aging Eye. Life (Basel) 2023; 13:life13030837. [PMID: 36983992 PMCID: PMC10052045 DOI: 10.3390/life13030837] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Given the expanding elderly population in the United States and the world, it is important to understand the processes underlying both natural and pathological age-related changes in the eye. Both the anterior and posterior segment of the eye undergo changes in biological, chemical, and physical properties driven by oxidative stress. With advancing age, changes in the anterior segment include dermatochalasis, blepharoptosis, thickening of the sclera, loss of corneal endothelial cells, and stiffening of the lens. Changes in the posterior segment include lowered viscoelasticity of the vitreous body, photoreceptor cell loss, and drusen deposition at the macula and fovea. Age-related ocular pathologies including glaucoma, cataracts, and age-related macular degeneration are largely mediated by oxidative stress. The prevalence of these diseases is expected to increase in the coming years, highlighting the need to develop new therapies that address oxidative stress and slow the progression of age-related pathologies.
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Affiliation(s)
- Deniz Goodman
- Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA
| | - Steven Ness
- Department of Ophthalmology, Boston Medical Center, Boston, MA 02118, USA
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26
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Serum Autoantibodies in Patients with Dry and Wet Age-Related Macular Degeneration. J Clin Med 2023; 12:jcm12041590. [PMID: 36836125 PMCID: PMC9960765 DOI: 10.3390/jcm12041590] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/02/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND To assess the serum autoantibody profile in patients with dry and exudative age-related macular degeneration compared with healthy volunteers to detect potential biomarkers, e.g., markers for progression of the disease. MATERIALS AND METHODS IgG Immunoreactivities were compared in patients suffering from dry age-related macular degeneration (AMD) (n = 20), patients with treatment-naive exudative AMD (n = 29) and healthy volunteers (n = 21). Serum was analysed by customized antigen microarrays containing 61 antigens. The statistical analysis was performed by univariate and multivariate analysis of variance, predictive data-mining methods and artificial neuronal networks were used to detect specific autoantibody patterns. RESULTS The immunoreactivities of dry and wet AMD patients were significantly different from each other and from controls. One of the most prominently changed reactivity was against alpha-synuclein (p ≤ 0.0034), which is known from other neurodegenerative diseases. Furthermore, reactivities against glyceraldehyde-3-phosphat-dehydrogenase (p ≤ 0.031) and Annexin V (p ≤ 0.034), which performs a major role in apoptotic processes, were significantly changed. Some immunoreacitvities were antithetic regulated in wet and dry-AMD, such as Vesicle transport-related protein (VTI-B). CONCLUSIONS Comparison of autoantibody profiles in patients with dry and wet AMD revealed significantly altered immunoreactivities against proteins particularly found in immunological diseases, further neurodegenerative, apoptotic and autoimmune markers could be observed. A validation study has to explore if these antibody pattern can help to understand the underlying differences in pathogenesis, evaluate their prognostic value and if those could be possibly useful as additional therapeutic targets.
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27
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Yednock T, Fong DS, Lad EM. C1q and the classical complement cascade in geographic atrophy secondary to age-related macular degeneration. Int J Retina Vitreous 2022; 8:79. [PMID: 36348407 PMCID: PMC9641935 DOI: 10.1186/s40942-022-00431-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 10/21/2022] [Indexed: 11/10/2022] Open
Abstract
Geographic atrophy (GA) secondary to age-related macular degeneration (AMD) is a retinal neurodegenerative disorder. Human genetic data support the complement system as a key component of pathogenesis in AMD, which has been further supported by pre-clinical and recent clinical studies. However, the involvement of the different complement pathways (classical, lectin, alternative), and thus the optimal complement inhibition target, has yet to be fully defined. There is evidence that C1q, the initiating molecule of the classical pathway, is a key driver of complement activity in AMD. C1q is expressed locally by infiltrating phagocytic cells and C1q-activating ligands are present at disease onset and continue to accumulate with disease progression. The accumulation of C1q on photoreceptor synapses with age and disease is consistent with its role in synapse elimination and neurodegeneration that has been observed in other neurodegenerative disorders. Furthermore, genetic deletion of C1q, local pharmacologic inhibition within the eye, or genetic deletion of downstream C4 prevents photoreceptor cell damage in mouse models. Hence, targeting the classical pathway in GA could provide a more specific therapeutic approach with potential for favorable efficacy and safety.
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Affiliation(s)
- Ted Yednock
- Annexon Biosciences, 1400 Sierra Point Parkway Building C, 2nd Floor, Brisbane, CA, 94005, USA
| | - Donald S Fong
- Annexon Biosciences, 1400 Sierra Point Parkway Building C, 2nd Floor, Brisbane, CA, 94005, USA.
| | - Eleonora M Lad
- Department of Ophthalmology, Duke University Medical Center, 2351 Erwin Rd, Durham, NC, 27705, USA
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28
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Tolentino MJ, Tolentino AJ. Investigational drugs in clinical trials for macular degeneration. Expert Opin Investig Drugs 2022; 31:1067-1085. [PMID: 35962560 DOI: 10.1080/13543784.2022.2113375] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Intravitreal anti-vascular endothelial growth factor (VEGF) injections for exudative age-related macular degeneration (eAMD) are effective and safe but require frequent injections and have nonresponding patients. Geographic atrophy/dry AMD (gaAMD) remains an unmet medical need . New therapies are needed to address this leading cause of blindness in the increasing aged population. AREAS COVERED This paper reviews the pathogenesis of macular degeneration, current and failed therapeutics, therapies undergoing clinical trials and a rationale for why certain AMD therapies may succeed or fail . EXPERT OPINION VEGF- inhibitors reduce both vascular leakage and neovascularization. Experimental therapies that only address neovascularization or leakage will unlikely supplant anti-VEGF therapies. The most promising future therapies for eAMD, are those that target, more potently inhibit and have a more sustained effect on the VEGF pathway such as KSI-301, RGX-314, CLS-AX, EYEP-1901, OTX-TKI. GaAMD is a phenotype of phagocytic retinal cell loss. Inhibiting phagocytic activity of retinal microglial/macrophages at the border of GA and reducing complement derived activators of microglial/macrophage is the most promising strategy. Complement inhibitors (Pegcetacoplan and Avacincaptad pegol) will likely obtain FDA approval but will serve to pave the way for combined complement and direct phagocytic inhibitors such as AVD-104.
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Affiliation(s)
- Michael J Tolentino
- University of Central Florida, FL, USA.,Blue Ocean Clinical Research, Lakeland, FL, USA.,Aviceda Therapeutics, Cambridge, MA, USA
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29
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Lewandowski D, Sander CL, Tworak A, Gao F, Xu Q, Skowronska-Krawczyk D. Dynamic lipid turnover in photoreceptors and retinal pigment epithelium throughout life. Prog Retin Eye Res 2022; 89:101037. [PMID: 34971765 PMCID: PMC10361839 DOI: 10.1016/j.preteyeres.2021.101037] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 12/13/2022]
Abstract
The retinal pigment epithelium-photoreceptor interphase is renewed each day in a stunning display of cellular interdependence. While photoreceptors use photosensitive pigments to convert light into electrical signals, the RPE supports photoreceptors in their function by phagocytizing shed photoreceptor tips, regulating the blood retina barrier, and modulating inflammatory responses, as well as regenerating the 11-cis-retinal chromophore via the classical visual cycle. These processes involve multiple protein complexes, tightly regulated ligand-receptors interactions, and a plethora of lipids and protein-lipids interactions. The role of lipids in maintaining a healthy interplay between the RPE and photoreceptors has not been fully delineated. In recent years, novel technologies have resulted in major advancements in understanding several facets of this interplay, including the involvement of lipids in phagocytosis and phagolysosome function, nutrient recycling, and the metabolic dependence between the two cell types. In this review, we aim to integrate the complex role of lipids in photoreceptor and RPE function, emphasizing the dynamic exchange between the cells as well as discuss how these processes are affected in aging and retinal diseases.
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Affiliation(s)
- Dominik Lewandowski
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Christopher L Sander
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Aleksander Tworak
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Fangyuan Gao
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Qianlan Xu
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA.
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30
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Sridevi Gurubaran I, Hytti M, Kaarniranta K, Kauppinen A. Epoxomicin, a Selective Proteasome Inhibitor, Activates AIM2 Inflammasome in Human Retinal Pigment Epithelium Cells. Antioxidants (Basel) 2022; 11:antiox11071288. [PMID: 35883779 PMCID: PMC9311580 DOI: 10.3390/antiox11071288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/26/2022] [Accepted: 06/26/2022] [Indexed: 02/04/2023] Open
Abstract
Emerging evidence suggests that the intracellular clearance system plays a vital role in maintaining homeostasis and in regulating oxidative stress and inflammation in retinal pigment epithelium (RPE) cells. Dysfunctional proteasomes and autophagy in RPE cells have been associated with the pathogenesis of age-related macular degeneration. We have previously shown that the inhibition of proteasomes using MG-132 activates the NLR family pyrin domain containing 3 (NLRP3) inflammasome in human RPE cells. However, MG-132 is a non-selective proteasome inhibitor. In this study, we used the selective proteasome inhibitor epoxomicin to study the effect of non-functional intracellular clearance systems on inflammasome activation. Our data show that epoxomicin-induced proteasome inhibition promoted both nicotinamide adenine dinucleotide phosphate oxidase and mitochondria-mediated oxidative stress and release of mitochondrial DNA to the cytosol, which resulted in potassium efflux-dependent absence in melanoma 2 (AIM2) inflammasome activation and subsequent interleukin-1β secretion in ARPE-19 cells. The non-specific proteasome inhibitor MG-132 activated both NLRP3 and AIM2 inflammasomes and oxidative stress predominated as the activation mechanism, but modest potassium efflux was also detected. Collectively, our data suggest that a selective proteasome inhibitor is a potent inflammasome activator in human RPE cells and emphasize the role of the AIM2 inflammasome in addition to the more commonly known NLRP3 inflammasome.
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Affiliation(s)
- Iswariyaraja Sridevi Gurubaran
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, 70210 Kuopio, Finland; (I.S.G.); (K.K.)
| | - Maria Hytti
- Immuno-Ophthalmology, School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland;
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, 70210 Kuopio, Finland; (I.S.G.); (K.K.)
- Department of Ophthalmology, University of Eastern Finland, 70211 Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, 70029 Kuopio, Finland
| | - Anu Kauppinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, 70210 Kuopio, Finland; (I.S.G.); (K.K.)
- Immuno-Ophthalmology, School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland;
- Correspondence:
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Casteel JL, Keever KR, Ardell CL, Williams DL, Gao D, Podrez EA, Byzova TV, Yakubenko VP. Modification of Extracellular Matrix by the Product of DHA Oxidation Switches Macrophage Adhesion Patterns and Promotes Retention of Macrophages During Chronic Inflammation. Front Immunol 2022; 13:867082. [PMID: 35720381 PMCID: PMC9204313 DOI: 10.3389/fimmu.2022.867082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/27/2022] [Indexed: 11/13/2022] Open
Abstract
Oxidation of polyunsaturated fatty acids contributes to different aspects of the inflammatory response due to the variety of products generated. Specifically, the oxidation of DHA produces the end-product, carboxyethylpyrrole (CEP), which forms a covalent adduct with proteins via an ϵ-amino group of lysines. Previously, we found that CEP formation is dramatically increased in inflamed tissue and CEP-modified albumin and fibrinogen became ligands for αDβ2 (CD11d/CD18) and αMβ2 (CD11b/CD18) integrins. In this study, we evaluated the effect of extracellular matrix (ECM) modification with CEP on the adhesive properties of M1-polarized macrophages, particularly during chronic inflammation. Using digested atherosclerotic lesions and in vitro oxidation assays, we demonstrated the ability of ECM proteins to form adducts with CEP, particularly, DHA oxidation leads to the formation of CEP adducts with collagen IV and laminin, but not with collagen I. Using integrin αDβ2-transfected HEK293 cells, WT and α D - / - mouse M1-polarized macrophages, we revealed that CEP-modified proteins support stronger cell adhesion and spreading when compared with natural ECM ligands such as collagen IV, laminin, and fibrinogen. Integrin αDβ2 is critical for M1 macrophage adhesion to CEP. Based on biolayer interferometry results, the isolated αD I-domain demonstrates markedly higher binding affinity to CEP compared to the "natural" αDβ2 ligand fibrinogen. Finally, the presence of CEP-modified proteins in a 3D fibrin matrix significantly increased M1 macrophage retention. Therefore, CEP modification converts ECM proteins to αDβ2-recognition ligands by changing a positively charged lysine to negatively charged CEP, which increases M1 macrophage adhesion to ECM and promotes macrophage retention during detrimental inflammation, autoimmunity, and chronic inflammation.
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Affiliation(s)
- Jared L. Casteel
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Kasey R. Keever
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Christopher L. Ardell
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - David L. Williams
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
- Department of Surgery, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Detao Gao
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Eugene A. Podrez
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Tatiana V. Byzova
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Valentin P. Yakubenko
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
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Liu Y, Bell BA, Song Y, Zhang K, Anderson B, Axelsen PH, Bohannan W, Agbaga M, Park HG, James G, Brenna JT, Schmidt K, Dunaief JL, Shchepinov MS. Deuterated docosahexaenoic acid protects against oxidative stress and geographic atrophy-like retinal degeneration in a mouse model with iron overload. Aging Cell 2022; 21:e13579. [PMID: 35257475 PMCID: PMC9009113 DOI: 10.1111/acel.13579] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/24/2022] [Accepted: 02/11/2022] [Indexed: 01/03/2023] Open
Abstract
Oxidative stress plays a central role in age-related macular degeneration (AMD). Iron, a potent generator of hydroxyl radicals through the Fenton reaction, has been implicated in AMD. One easily oxidized molecule is docosahexaenoic acid (DHA), the most abundant polyunsaturated fatty acid in photoreceptor membranes. Oxidation of DHA produces toxic oxidation products including carboxyethylpyrrole (CEP) adducts, which are increased in the retinas of AMD patients. In this study, we hypothesized that deuterium substitution on the bis-allylic sites of DHA in photoreceptor membranes could prevent iron-induced retinal degeneration by inhibiting oxidative stress and lipid peroxidation. Mice were fed with either DHA deuterated at the oxidation-prone positions (D-DHA) or control natural DHA and then given an intravitreal injection of iron or control saline. Orally administered D-DHA caused a dose-dependent increase in D-DHA levels in the neural retina and retinal pigment epithelium (RPE) as measured by mass spectrometry. At 1 week after iron injection, D-DHA provided nearly complete protection against iron-induced retinal autofluorescence and retinal degeneration, as determined by in vivo imaging, electroretinography, and histology. Iron injection resulted in carboxyethylpyrrole conjugate immunoreactivity in photoreceptors and RPE in mice fed with natural DHA but not D-DHA. Quantitative PCR results were consistent with iron-induced oxidative stress, inflammation, and retinal cell death in mice fed with natural DHA but not D-DHA. Taken together, our findings suggest that DHA oxidation is central to the pathogenesis of iron-induced retinal degeneration. They also provide preclinical evidence that dosing with D-DHA could be a viable therapeutic strategy for retinal diseases involving oxidative stress.
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Affiliation(s)
- Yingrui Liu
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Brent A. Bell
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Ying Song
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Kevin Zhang
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Brandon Anderson
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Paul H. Axelsen
- Department of PharmacologyPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Whitney Bohannan
- Departments of Cell Biology and OphthalmologyUniversity of Oklahoma Health Sciences Center and the Dean McGee Eye InstituteOklahoma CityOklahomaUSA
| | - Martin‐Paul Agbaga
- Departments of Cell Biology and OphthalmologyUniversity of Oklahoma Health Sciences Center and the Dean McGee Eye InstituteOklahoma CityOklahomaUSA
| | - Hui Gyu Park
- Dell Pediatric Research InstituteUniversity of Texas at AustinAustinTexasUSA
| | - Genevieve James
- Dell Pediatric Research InstituteUniversity of Texas at AustinAustinTexasUSA
| | - J. Thomas Brenna
- Dell Pediatric Research InstituteUniversity of Texas at AustinAustinTexasUSA
| | | | - Joshua L. Dunaief
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
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Różanowska MB, Różanowski B. Photodegradation of Lipofuscin in Suspension and in ARPE-19 Cells and the Similarity of Fluorescence of the Photodegradation Product with Oxidized Docosahexaenoate. Int J Mol Sci 2022; 23:ijms23020922. [PMID: 35055111 PMCID: PMC8778276 DOI: 10.3390/ijms23020922] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 02/01/2023] Open
Abstract
Retinal lipofuscin accumulates with age in the retinal pigment epithelium (RPE), where its fluorescence properties are used to assess retinal health. It was observed that there is a decrease in lipofuscin fluorescence above the age of 75 years and in the early stages of age-related macular degeneration (AMD). The purpose of this study was to investigate the response of lipofuscin isolated from human RPE and lipofuscin-laden cells to visible light, and to determine whether an abundant component of lipofuscin, docosahexaenoate (DHA), can contribute to lipofuscin fluorescence upon oxidation. Exposure of lipofuscin to visible light leads to a decrease in its long-wavelength fluorescence at about 610 nm, with a concomitant increase in the short-wavelength fluorescence. The emission spectrum of photodegraded lipofuscin exhibits similarity with that of oxidized DHA. Exposure of lipofuscin-laden cells to light leads to a loss of lipofuscin granules from cells, while retaining cell viability. The spectral changes in fluorescence in lipofuscin-laden cells resemble those seen during photodegradation of isolated lipofuscin. Our results demonstrate that fluorescence emission spectra, together with quantitation of the intensity of long-wavelength fluorescence, can serve as a marker useful for lipofuscin quantification and for monitoring its oxidation, and hence useful for screening the retina for increased oxidative damage and early AMD-related changes.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK
- Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff CF10 3NB, UK
- Correspondence: ; Tel.: +44-2920875057
| | - Bartosz Różanowski
- Institute of Biology, Pedagogical University of Kraków, 30-084 Kraków, Poland;
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Xiong L, McCoy M, Komuro H, West XZ, Yakubenko V, Gao D, Dudiki T, Milo A, Chen J, Podrez EA, Trapp B, Byzova TV. Inflammation-dependent oxidative stress metabolites as a hallmark of amyotrophic lateral sclerosis. Free Radic Biol Med 2022; 178:125-133. [PMID: 34871763 PMCID: PMC8744315 DOI: 10.1016/j.freeradbiomed.2021.11.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/24/2021] [Accepted: 11/22/2021] [Indexed: 01/03/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease, with poor prognosis and no cure. Substantial evidence implicates inflammation and associated oxidative stress as a potential mechanism for ALS, especially in patients carrying the SOD1 mutation and, therefore, lacking anti-oxidant defense. The brain is particularly vulnerable to oxidation due to the abundance of polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), which can give rise to several oxidized metabolites. Accumulation of a DHA peroxidation product, CarboxyEthylPyrrole (CEP) is dependent on activated inflammatory cells and myeloperoxidase (MPO), and thus marks areas of inflammation-associated oxidative stress. At the same time, generation of an alternative inactive DHA peroxidation product, ethylpyrrole, does not require cell activation and MPO activity. While absent in normal brain tissues, CEP is accumulated in the central nervous system (CNS) of ALS patients, reaching particularly high levels in individuals carrying a SOD1 mutation. ALS brains are characterized by high levels of MPO and lowered anti-oxidant activity (due to the SOD1 mutation), thereby aiding CEP generation and accumulation. Due to DHA oxidation within the membranes, CEP marks cells with the highest oxidative damage. In all ALS cases CEP is present in nearly all astrocytes and microglia, however, only in individuals carrying a SOD1 mutation CEP marks >90% of neurons, thereby emphasizing an importance of CEP accumulation as a potential hallmark of oxidative damage in neurodegenerative diseases.
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Affiliation(s)
- Luyang Xiong
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Michael McCoy
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Hitoshi Komuro
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Xiaoxia Z West
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Valentin Yakubenko
- Department of Biomedical Sciences, Center of Excellence for Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, 37684, USA
| | - Detao Gao
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Tejasvi Dudiki
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Amanda Milo
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jacqueline Chen
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Eugene A Podrez
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Bruce Trapp
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Tatiana V Byzova
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
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Schäfer N, Rasras A, Ormenisan DM, Amslinger S, Enzmann V, Jägle H, Pauly D. Complement Factor H-Related 3 Enhanced Inflammation and Complement Activation in Human RPE Cells. Front Immunol 2021; 12:769242. [PMID: 34819935 PMCID: PMC8606654 DOI: 10.3389/fimmu.2021.769242] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/18/2021] [Indexed: 12/14/2022] Open
Abstract
Complement Factor H-Related 3 (FHR-3) is a major regulator of the complement system, which is associated with different diseases, such as age-related macular degeneration (AMD). However, the non-canonical local, cellular functions of FHR-3 remained poorly understood. Here, we report that FHR-3 bound to oxidative stress epitopes and competed with FH for interaction. Furthermore, FHR-3 was internalized by viable RPE cells and modulated time-dependently complement component (C3, FB) and receptor (C3aR, CR3) expression of human RPE cells. Independently of any external blood-derived proteins, complement activation products were detected. Anaphylatoxin C3a was visualized in treated cells and showed a translocation from the cytoplasm to the cell membrane after FHR-3 exposure. Subsequently, FHR-3 induced a RPE cell dependent pro-inflammatory microenvironment. Inflammasome NLRP3 activation and pro-inflammatory cytokine secretion of IL-1ß, IL-18, IL-6 and TNF-α were induced after FHR-3-RPE interaction. Our previously published monoclonal anti-FHR-3 antibody, which was chimerized to reduce immunogenicity, RETC-2-ximab, ameliorated the effect of FHR-3 on ARPE-19 cells. Our studies suggest FHR-3 as an exogenous trigger molecule for the RPE cell "complosome" and as a putative target for a therapeutic approach for associated degenerative diseases.
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Affiliation(s)
- Nicole Schäfer
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
- Department of Orthopaedic Surgery, Experimental Orthopaedics, Centre for Medical Biotechnology (ZMB), University of Regensburg, Regensburg, Germany
| | - Anas Rasras
- Chemistry Department, Al-Balqa Applied University, Al-Salt, Jordan
- Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany
| | - Delia M. Ormenisan
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
| | - Sabine Amslinger
- Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany
| | - Volker Enzmann
- Department of Ophthalmology, University Hospital of Bern and Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Herbert Jägle
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
| | - Diana Pauly
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
- Experimental Ophthalmology, Philipps-University Marburg, Marburg, Germany
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Chen C, Wang C, Zhou X, Xu L, Chen H, Qian K, Jia B, Su G, Fu J. Nonsteroidal anti-inflammatory drugs for retinal neurodegenerative diseases. Prostaglandins Other Lipid Mediat 2021; 156:106578. [PMID: 34245897 DOI: 10.1016/j.prostaglandins.2021.106578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 06/29/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most common prescription drugs for inflammation, and topical NSAIDs are often used in ophthalmology to reduce pain, photophobia, inflammation, and edema. In recent years, many published reports have found that NSAIDs play an important role in the treatment of retinal neurodegenerative diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma, pathological myopia, and retinitis pigmentosa (RP). The aim of the current review is to provide an overview of the role of various NSAIDs in the treatment of retinal neurodegenerative diseases and the corresponding mechanisms of action. This review highlighted that the topical application of NSAIDs for the treatment of retinal degenerative diseases has been studied to a remarkable extent and that its beneficial effects in many diseases have been proven. In the future, prospective studies with large study populations are required to extend these effects to clinical settings.
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Affiliation(s)
- Chen Chen
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Chenguang Wang
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Xuebin Zhou
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Lingxian Xu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Han Chen
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Kun Qian
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Bo Jia
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Guanfang Su
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
| | - Jinling Fu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China.
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Retinal Pigment Epithelium Expressed Toll-like Receptors and Their Potential Role in Age-Related Macular Degeneration. Int J Mol Sci 2021; 22:ijms22168387. [PMID: 34445096 PMCID: PMC8395065 DOI: 10.3390/ijms22168387] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 01/17/2023] Open
Abstract
(1) Background: Inflammation is a major pathomechanism in the development and progression of age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) may contribute to retinal inflammation via activation of its Toll-like receptors (TLR). TLR are pattern recognition receptors that detect the pathogen- or danger-associated molecular pattern. The involvement of TLR activation in AMD is so far not understood. (2) Methods: We performed a systematic literature research, consulting the National Library of Medicine (PubMed). (3) Results: We identified 106 studies, of which 54 were included in this review. Based on these studies, the current status of TLR in AMD, the effects of TLR in RPE activation and of the interaction of TLR activated RPE with monocytic cells are given, and the potential of TLR activation in RPE as part of the AMD development is discussed. (4) Conclusion: The activation of TLR2, -3, and -4 induces a profound pro-inflammatory response in the RPE that may contribute to (long-term) inflammation by induction of pro-inflammatory cytokines, reducing RPE function and causing RPE cell degeneration, thereby potentially constantly providing new TLR ligands, which could perpetuate and, in the long run, exacerbate the inflammatory response, which may contribute to AMD development. Furthermore, the combined activation of RPE and microglia may exacerbate neurotoxic effects.
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Annamalai B, Parsons N, Nicholson C, Joseph K, Coughlin B, Yang X, Jones BW, Tomlinson S, Rohrer B. Natural immunoglobulin M-based delivery of a complement alternative pathway inhibitor in mouse models of retinal degeneration. Exp Eye Res 2021; 207:108583. [PMID: 33878326 PMCID: PMC8504679 DOI: 10.1016/j.exer.2021.108583] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 03/31/2021] [Accepted: 04/13/2021] [Indexed: 11/23/2022]
Abstract
PURPOSE Age-related macular degeneration is a slowly progressing disease. Studies have tied disease risk to an overactive complement system. We have previously demonstrated that pathology in two mouse models, the choroidal neovascularization (CNV) model and the smoke-induced ocular pathology (SIOP) model, can be reduced by specifically inhibiting the alternative complement pathway (AP). Here we report on the development of a novel injury-site targeted inhibitor of the alternative pathway, and its characterization in models of retinal degeneration. METHODS Expression of the danger associated molecular pattern, a modified annexin IV, in injured ARPE-19 cells was confirmed by immunohistochemistry and complementation assays using B4 IgM mAb. Subsequently, a construct was prepared consisting of B4 single chain antibody (scFv) linked to a fragment of the alternative pathway inhibitor, fH (B4-scFv-fH). ARPE-19 cells stably expressing B4-scFv-fH were microencapsulated and administered intravitreally or subcutaneously into C57BL/6 J mice, followed by CNV induction or smoke exposure. Progression of CNV was analyzed using optical coherence tomography, and SIOP using structure-function analyses. B4-scFv-fH targeting and AP specificity was assessed by Western blot and binding experiments. RESULTS B4-scFv-fH was secreted from encapsulated RPE and inhibited complement in RPE monolayers. B4-scFv-fH capsules reduced CNV and SIOP, and western blotting for breakdown products of C3α, IgM and IgG confirmed a reduction in complement activation and antibody binding in RPE/choroid. CONCLUSIONS Data supports a role for natural antibodies and neoepitope expression in ocular disease, and describes a novel strategy to target AP-specific complement inhibition to diseased tissue in the eye. PRECIS AMD risk is tied to an overactive complement system, and ocular injury is reduced by alternative pathway (AP) inhibition in experimental models. We developed a novel inhibitor of the AP that targets an injury-specific danger associated molecular pattern, and characterized it in disease models.
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Affiliation(s)
| | - Nathaniel Parsons
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA
| | - Crystal Nicholson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA
| | - Kusumam Joseph
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA
| | - Beth Coughlin
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA
| | - Xiaofeng Yang
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, USA
| | - Bryan W Jones
- Department of Ophthalmology, University of Utah, Salt Lake City, UT, USA
| | - Stephen Tomlinson
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Division of Research, Charleston, SC, USA
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Division of Research, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
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Provis JM, Penfold PL, Cornish EE, Sandercoe TM, Madigan MC. Anatomy and development of the macula: specialisation and the vulnerability to macular degeneration. Clin Exp Optom 2021; 88:269-81. [PMID: 16255686 DOI: 10.1111/j.1444-0938.2005.tb06711.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 06/27/2005] [Accepted: 07/01/2005] [Indexed: 01/14/2023] Open
Abstract
The central retina in primates is adapted for high acuity vision. The most significant adaptations to neural retina in this respect are: 1. The very high density of cone photoreceptors on the visual axis; 2. The dominance of Midget pathways arising from these cones and 3. The diminishment of retinal blood supply in the macula, and its absence on the visual axis. Restricted blood supply to the part of the retina that has the highest density of neural elements is paradoxical. Inhibition of vascular growth and proliferation is evident during foetal life and results in metabolic stress in ganglion cells and Muller cells, which is resolved during formation of the foveal depression. In this review we argue that at the macula stressed retinal neurons adapt during development to a limited blood supply from the choriocapillaris, which supplies little in excess of metabolic demand of the neural retina under normal conditions. We argue also that while adaptation of the choriocapillaris underlying the foveal region may initially augment the local supply of oxygen and nutrients by diffusion, in the long term these adaptations make the region more vulnerable to age-related changes, including the accumulation of insoluble material in Bruch's membrane and beneath the retinal pigment epithelium. These changes eventually impact on delivery of oxygen and nutrients to the RPE and outer neural retina because of reduced flow in the choriocapillaris and the increasing barriers to effective diffusion. Both the inflammatory response and the sequelae of oxidative stress are predictable outcomes in this scenario.
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Affiliation(s)
- Jan M Provis
- Research School of Biological Sciences, The Australian National University, GPO Box 475, Canberra, ACT, 2601, Australia.
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Różanowska MB, Pawlak A, Różanowski B. Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin. Int J Mol Sci 2021; 22:ijms22073525. [PMID: 33805370 PMCID: PMC8037991 DOI: 10.3390/ijms22073525] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/16/2022] Open
Abstract
Retinal lipofuscin which accumulates with age in the retinal pigment epithelium (RPE) is subjected to daily exposures to high fluxes of visible light and exhibits potent photosensitising properties; however, the molecules responsible for its photoreactivity remain unknown. Here, we demonstrate that autooxidation of docosahexaenoate (DHE) leads to the formation of products absorbing, in addition to UVB and UVA light, also visible light. The products of DHE oxidation exhibit potent photosensitising properties similar to photosensitising properties of lipofuscin, including generation of an excited triplet state with similar characteristics as the lipofuscin triplet state, and photosensitised formation of singlet oxygen and superoxide. The quantum yields of singlet oxygen and superoxide generation by oxidised DHE photoexcited with visible light are 2.4- and 3.6-fold higher, respectively, than for lipofuscin, which is consistent with the fact that lipofuscin contains some chromophores which do contribute to the absorption of light but not so much to its photosensitising properties. Importantly, the wavelength dependence of photooxidation induced by DHE oxidation products normalised to equal numbers of incident photons is also similar to that of lipofuscin—it steeply increases with decreasing wavelength. Altogether, our results demonstrate that products of DHE oxidation include potent photosensitiser(s) which are likely to contribute to lipofuscin photoreactivity.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, Wales, UK
- Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff CF24 4HQ, Wales, UK
- Correspondence: ; Tel.: +44-292087-5057
| | - Anna Pawlak
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
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Toll-like Receptor 2 Facilitates Oxidative Damage-Induced Retinal Degeneration. Cell Rep 2021; 30:2209-2224.e5. [PMID: 32075760 PMCID: PMC7179253 DOI: 10.1016/j.celrep.2020.01.064] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/18/2019] [Accepted: 01/21/2020] [Indexed: 12/11/2022] Open
Abstract
Retinal degeneration is a form of neurodegenerative disease and is the leading cause of vision loss globally. The Toll-like receptors (TLRs) are primary components of the innate immune system involved in signal transduction. Here we show that TLR2 induces complement factors C3 and CFB, the common and rate-limiting factors of the alternative pathway in both retinal pigment epithelial (RPE) cells and mononuclear phagocytes. Neutralization of TLR2 reduces opsonizing fragments of C3 in the outer retina and protects photoreceptor neurons from oxidative stress-induced degeneration. TLR2 deficiency also preserves tight junction expression and promotes RPE resistance to fragmentation. Finally, oxidative stress-induced formation of the terminal complement membrane attack complex and Iba1+ cell infiltration are strikingly inhibited in the TLR2-deficient retina. Our data directly implicate TLR2 as a mediator of retinal degeneration in response to oxidative stress and present TLR2 as a bridge between oxidative damage and complement-mediated retinal pathology. Oxidative stress and complement deposition are common to many retinal degenerative diseases. Mulfaul et al. demonstrate that TLR2 blockade protects against photoreceptor neuronal cell death and RPE fragmentation in experimental models of oxidative stress-induced retinal degeneration and present TLR2 as a bridge between oxidative damage and complement-mediated retinal pathology.
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Mulfaul K, Doyle SL. In vitro Measurement of Membrane Attack Complex in RPE Cells. Bio Protoc 2021; 11:e3916. [PMID: 33732803 DOI: 10.21769/bioprotoc.3916] [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: 06/22/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 11/02/2022] Open
Abstract
Initiation of the complement system results in the formation of a multiprotein pore termed the membrane attack complex (MAC, C5b-C9). MAC pores accumulate on a cell surface and can result in cell lysis. The retinal pigment epithelium (RPE) is a single monolayer of pigmented epithelial cells located at the posterior poll of the eye that forms the outer blood retinal barrier. RPE cells are highly polarized with apical microvilli and basolateral contact with Bruch's membrane. In order to obtain biologically relevant polarized RPE cultures in vitro, RPE cells are seeded onto the apical side of a transwell filter and cultured for 4 weeks in low serum media. MAC formation on RPE cells has been reported to be sub-lytic. MAC formation can be achieved in vitro by introduction of normal human serum (NHS) to media following serum starvation for 24 h. NHS contains all serum complement proteins required to initiate complement activation and MAC formation. We combined in vitro RPE polarization and complement activation to visualize MAC formation in vitro utilizing confocal microscopy allowing for high resolution MAC imaging.
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Affiliation(s)
- Kelly Mulfaul
- Dept. Clinical Medicine, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Sarah L Doyle
- Dept. Clinical Medicine, School of Medicine, Trinity College Dublin, Dublin, Ireland.,Trinity College Institute of Neuroscience (TCIN), TCD, Dublin, Ireland.,The National Children's Research Centre, Our Lady's Hospital Crumlin, Dublin, Ireland
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Mitochondria: The Retina's Achilles' Heel in AMD. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1256:237-264. [PMID: 33848005 DOI: 10.1007/978-3-030-66014-7_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Strong experimental evidence from studies in human donor retinas and animal models supports the idea that the retinal pathology associated with age-related macular degeneration (AMD) involves mitochondrial dysfunction and consequent altered retinal metabolism. This chapter provides a brief overview of mitochondrial structure and function, summarizes evidence for mitochondrial defects in AMD, and highlights the potential ramifications of these defects on retinal health and function. Discussion of mitochondrial haplogroups and their association with AMD brings to light how mitochondrial genetics can influence disease outcome. As one of the most metabolically active tissues in the human body, there is strong evidence that disruption in key metabolic pathways contributes to AMD pathology. The section on retinal metabolism reviews cell-specific metabolic differences and how the metabolic interdependence of each retinal cell type creates a unique ecosystem that is disrupted in the diseased retina. The final discussion includes strategies for therapeutic interventions that target key mitochondrial pathways as a treatment for AMD.
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Immunological Aspects of Age-Related Macular Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1256:143-189. [PMID: 33848001 DOI: 10.1007/978-3-030-66014-7_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Increasing evidence over the past two decades points to a pivotal role for immune mechanisms in age-related macular degeneration (AMD) pathobiology. In this chapter, we will explore immunological aspects of AMD, with a specific focus on how immune mechanisms modulate clinical phenotypes of disease and severity and how components of the immune system may serve as triggers for disease progression in both dry and neovascular AMD. We will briefly review the biology of the immune system, defining the role of immune mechanisms in chronic degenerative disease and differentiating from immune responses to acute injury or infection. We will explore current understanding of the roles of innate immunity (especially macrophages), antigen-specific immunity (T cells, B cells, and autoimmunity), immune amplifications systems, especially complement activity and the NLRP3 inflammasome, in the pathogenesis of both dry and neovascular AMD, reviewing data from pathology, experimental animal models, and clinical studies of AMD patients. We will also assess how interactions between the immune system and infectious pathogens could potentially modulate AMD pathobiology via alterations in in immune effector mechanisms. We will conclude by reviewing the paradigm of "response to injury," which provides a means to integrate various immunologic mechanisms along with nonimmune mechanisms of tissue injury and repair as a model to understand the pathobiology of AMD.
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Cheng YS, Linetsky M, Li H, Ayyash N, Gardella A, Salomon RG. 4-Hydroxy-7-oxo-5-heptenoic acid lactone can induce mitochondrial dysfunction in retinal pigmented epithelial cells. Free Radic Biol Med 2020; 160:719-733. [PMID: 32920040 PMCID: PMC7704664 DOI: 10.1016/j.freeradbiomed.2020.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/25/2020] [Accepted: 09/04/2020] [Indexed: 11/30/2022]
Abstract
Oxidation of docosahexaenoate (DHA)-containing phospholipids in the cell plasma membrane leads to release of the α,β-unsaturated aldehyde 4-hydroxy-7-oxo-5-heptenoic acid (HOHA) lactone which is capable of inducing retinal pigmented epithelial (RPE) cell dysfunction. Previously, HOHA lactone was shown to induce apoptosis and angiogenesis, and to activate the alternative complement pathway. RPE cells metabolize HOHA lactone through enzymatic conjugation with glutathione (GSH). Competing with this process is the adduction of HOHA lactone to protein lysyl residues generating 2-(ω-carboxyethyl)pyrrole (CEP) derivatives that have pathological relevance to age-related macular degeneration (AMD). We now find that HOHA lactone induces mitochondrial dysfunction. It decreases ATP levels, mitochondrial membrane potentials, enzymatic activities of mitochondrial complexes, depletes GSH and induces oxidative stress in RPE cells. The present study confirmed that pyridoxamine and other primary amines, which have been shown to scavenge γ-ketoaldehydes formed by carbohydrate or lipid peroxidation, are ineffective for scavenging the α,β-unsaturated aldehydes. Histidyl hydrazide (HH), that has both hydrazide and imidazole nucleophile functionalities, is an effective scavenger of HOHA lactone and it protects ARPE-19 cells against HOHA lactone-induced cytotoxicity. The HH α-amino group is not essential for this electrophile trapping activity. The Nα-acyl L-histidyl hydrazide derivatives with 2- to 7-carbon acyl groups with increasing lipophilicities are capable of maintaining the effectiveness of HH in protecting ARPE-19 cells against HOHA lactone toxicity, which potentially has therapeutic utility for treatment of age related eye diseases.
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Affiliation(s)
- Yu-Shiuan Cheng
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Mikhail Linetsky
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA; Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Haoting Li
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Naji Ayyash
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Anthony Gardella
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Robert G Salomon
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA; Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA.
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The pathogenesis of age-related macular degeneration is not inflammatory mediated but is instead due to immunosenescence-related failure of tissue repair. Med Hypotheses 2020; 146:110392. [PMID: 33246696 DOI: 10.1016/j.mehy.2020.110392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/08/2020] [Indexed: 01/13/2023]
Abstract
A natural consequence of everyday tissue metabolism is cell injury or stress. This injury activates a canonical immune-mediated inflammatory response in order to achieve tissue repair so that homeostasis is maintained. With aging there is increased tissue injury and therefore increasing demands placed on an immune system, which itself is aging (immunosenescence). Thus, the increased reparative demands are reflected by an increased inflammatory load both locally and systemically. Eventually, if the reparative demands are excessive, the aging immune system is overwhelmed and disease ensues. In the macula this age-related failure in repair gives rise to age-related macular degeneration (AMD). The hypothesis proposed herein is therefore, that AMD is due to age-related failure of tissue repair and the chronic inflammation associated with this failure ('inflammaging') is both a surrogate and biomarker of this reparative failure and not in itself the primary cause of disease. Such a hypothesis can be applied to all the diseases of aging and by extension suggests that effective therapies should be aimed at facilitating repair through immunotherapy, possibly and perhaps controversially, through the promotion of inflammation rather than the current approach of its inhibition (anti-inflammatory strategies), the latter which can ultimately only hinder the repair process and thereby lead to the persistence of disease.
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An In-Vitro Cell Model of Intracellular Protein Aggregation Provides Insights into RPE Stress Associated with Retinopathy. Int J Mol Sci 2020; 21:ijms21186647. [PMID: 32932802 PMCID: PMC7555953 DOI: 10.3390/ijms21186647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/30/2020] [Accepted: 09/07/2020] [Indexed: 12/11/2022] Open
Abstract
Impaired cargo trafficking and the aggregation of intracellular macromolecules are key features of neurodegeneration, and a hallmark of aged as well as diseased retinal pigment epithelial (RPE) cells in the eye. Here, photoreceptor outer segments (POS), which are internalized daily by RPE cells, were modified by UV-irradiation to create oxidatively modified POS (OxPOS). Oxidative modification was quantified by a protein carbonyl content assay. Human ARPE-19 cells were synchronously pulsed with POS or OxPOS to study whether oxidatively modified cargos can recapitulate features of RPE pathology associated with blinding diseases. Confocal immunofluorescence microscopy analysis showed that OxPOS was trafficked to LAMP1, LAMP2 lysosomes and to LC3b autophagy vacuoles. Whilst POS were eventually degraded, OxPOS cargos were sequestered in late compartments. Co-localization of OxPOS was also associated with swollen autolysosomes. Ultrastructural analysis revealed the presence of electron-dense OxPOS aggregates in RPE cells, which appeared to be largely resistant to degradation. Measurement of cellular autofluorescence, using parameters used to assess fundus autofluorescence (FAF) in age-related macular disease (AMD) patients, revealed that OxPOS contributed significantly to a key feature of aged and diseased RPE. This in vitro cell model therefore represents a versatile tool to study disease pathways linked with RPE damage and sight-loss.
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Sheludchenko VM. [Influence of docosahexaenoic acid treatment on visual acuity, visual field and bioelectric potential of the retina in patients with retinitis pigmentosa]. Vestn Oftalmol 2020; 136:296-299. [PMID: 32880154 DOI: 10.17116/oftalma2020136042296] [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: 11/18/2022]
Abstract
Retinitis pigmentosa (PR) is manifested by decreased vision, night blindness and narrowing of the visual field. In RP, the level of docosahexaenoic acid (DHA) in blood plasma and red blood cells is significantly reduced. The largest amount of DHA is contained in the retina (30-40% of phospholipids). DHA increases membrane permeability, accelerates the release of vital proteins and retinal enzymes, provides differentiation of photoreceptors, and slows down apoptosis. The introduction of DHA in isolation or in combination with other fatty acids into the body increases its concentration and can be used for metabolism. While there is a known correlation between the level of DHA in the blood and certain retinal functions (visual acuity, light sensitivity, the value of bioelectric potential), many years of multicenter studies have not produced reliable data on the direct effect of isolated or combined use of DHA in maintaining retinal functions in PR. Despite inconsistent outcomes, the clinical trials should continue.
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Annamalai B, Nicholson C, Parsons N, Stephenson S, Atkinson C, Jones B, Rohrer B. Immunization Against Oxidized Elastin Exacerbates Structural and Functional Damage in Mouse Model of Smoke-Induced Ocular Injury. Invest Ophthalmol Vis Sci 2020; 61:45. [PMID: 32207814 PMCID: PMC7401451 DOI: 10.1167/iovs.61.3.45] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose Age-related macular degeneration (AMD) is the leading cause of blindness in Western populations. While an overactive complement system has been linked to pathogenesis, mechanisms contributing to its activation are largely unknown. In aged and AMD eyes, loss of the elastin layer (EL) of Bruch's membrane (BrM) has been reported. Elastin antibodies are elevated in patients with AMD, the pathogenic significance of which is unclear. Here we assess the role of elastin antibodies using a mouse model of smoke-induced ocular pathology (SIOP), which similarly demonstrates EL loss. Methods C57BL/6J mice were immunized with elastin or elastin peptide oxidatively modified by cigarette smoke (ox-elastin). Mice were then exposed to cigarette smoke or air for 6 months. Visual function was assessed by optokinetic response, retinal morphology by spectral-domain optical coherence tomography and electron microscopy, and complement activation and antibody deposition by Western blot. Results Ox-elastin IgG and IgM antibodies were elevated in ox-elastin immunized mice following 6 months of smoke, whereas elastin immunization had a smaller effect. Ox-elastin immunization exacerbated smoke-induced vision loss, with thicker BrM and more damaged retinal pigment epithelium (RPE) mitochondria compared with mice immunized with elastin or nonimmunized controls. These changes were correlated with increased levels of IgM, IgG2, IgG3, and complement activation products in RPE/choroid. Conclusions These data demonstrate that SIOP mice generate elastin-specific antibodies and that immunization with ox-elastin exacerbates ocular pathology. Elastin antibodies represented complement fixing isotypes that, together with the increased presence of complement activation seen in immunized mice, suggest that elastin antibodies exert pathogenic effects through mediating complement activation.
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Linetsky M, Guo J, Udeigwe E, Ma D, Chamberlain AS, Yu AO, Solovyova K, Edgar E, Salomon RG. 4-Hydroxy-7-oxo-5-heptenoic acid (HOHA) lactone induces apoptosis in retinal pigment epithelial cells. Free Radic Biol Med 2020; 152:280-294. [PMID: 32222470 PMCID: PMC7276294 DOI: 10.1016/j.freeradbiomed.2020.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 02/06/2023]
Abstract
Retinal pigment epithelial (RPE) cell dysfunction and death play vital roles in age-related macular degeneration (AMD) pathogenesis. Previously we showed that oxidative cleavage of docosahexenoate (DHA) phospholipids generates an α,β-unsaturated aldehyde, 4-hydroxy-7-oxohept-4-enoic acid (HOHA) lactone, that forms ω-carboxyethylpyrrole (CEP) derivatives through adduction to proteins and ethanolamine phospholipids. CEP derivatives and autoantibodies accumulate in the retinas and blood plasma of individuals with AMD and are a biomarker of AMD. They promote the choroidal neovascularization of "wet AMD". Immunization of mice with CEP-modified mouse serum albumin induces "dry AMD"-like lesions in their retinas as well as interferon-gamma and interleukin-17 production by CEP-specific T cells that promote inflammatory M1 polarization of macrophages. The present study confirms that oxidative stress or inflammatory stimulus produces CEP in both the primary human ARPE-19 cell line and hRPE cells. Exposure of these cells to HOHA lactone fosters production of reactive oxygen species. Thus, HOHA lactone participates in a vicious cycle, promoting intracellular oxidative stress leading to oxidative cleavage of DHA to produce more HOHA lactone. We now show that HOHA lactone is cytotoxic, inducing apoptotic cell death through activation of the intrinsic pathway. This suggests that therapeutic interventions targeting HOHA lactone-induced apoptosis may prevent the loss of RPE cells during the early phase of AMD. We also discovered that ARPE-19 cells are more susceptible than hRPE cells to HOHA lactone cytotoxicity. This is consistent with the view that, compared to normal RPE cells, ARPE-19 cells exhibit a diseased RPE phenotype that also includes elevated expression of the mesenchymal indicator vimentin, elevated integrin a5 promotor strength and deficient secretion of the anti-VEGF molecule pigment-epithelium-derived factor fostering weaker tight junctions.
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Affiliation(s)
- Mikhail Linetsky
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA; Department of Ophthalmology and Visual Sciences, Case Western Reserve University, USA
| | - Junhong Guo
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Emeka Udeigwe
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Duoming Ma
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Amanda S Chamberlain
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Annabelle O Yu
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Kseniya Solovyova
- Department of Chemistry, Cleveland State University, Cleveland, OH, 44115, USA
| | - Elise Edgar
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Robert G Salomon
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA; Department of Ophthalmology and Visual Sciences, Case Western Reserve University, USA.
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