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Faatz H, Lommatzsch A. Overview of the Use of Optical Coherence Tomography Angiography in Neovascular Age-Related Macular Degeneration. J Clin Med 2024; 13:5042. [PMID: 39274255 PMCID: PMC11396513 DOI: 10.3390/jcm13175042] [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: 06/17/2024] [Revised: 08/19/2024] [Accepted: 08/22/2024] [Indexed: 09/16/2024] Open
Abstract
The aim of this review is to present and discuss the use of optical coherence tomography angiography (OCTA) in age-related macular degeneration (AMD). OCTA is a non-invasive imaging procedure that gives a detailed indirect view of physiological and pathological vessels in the retina and choroid membrane. Compared with dye-based imaging, OCTA provides a segmented presentation of the individual vascular layers and plexuses, thus enabling previously unattainable differentiation and classification of pathological vascular changes within or underneath the retina. In particular, OCTA facilitates early detection of exudative macular neovascularizations (MNV) so that treatment with anti-VEGF medication can be initiated. Moreover, in the context of both screening and therapy monitoring, it is hoped that OCTA can provide more detailed data to enable greater personalization of treatment and follow-up. The image quality of OCTA is, however, susceptible to artifacts, and validation of the results by studies is required. Recent developments have shown constant improvement both in the algorithms for image calculation and avoidance of artifacts and in image quality, so the scope of OCTA will certainly expand with time.
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Affiliation(s)
- Henrik Faatz
- Eye Center, St. Franziskus Hospital Münster, 48145 Münster, Germany
- Achim Wessing Institute for Imaging in Ophthalmology, University of Essen-Duisburg, 45147 Essen, Germany
- Department of Ophthalmology, University of Essen-Duisburg, 45147 Essen, Germany
| | - Albrecht Lommatzsch
- Eye Center, St. Franziskus Hospital Münster, 48145 Münster, Germany
- Achim Wessing Institute for Imaging in Ophthalmology, University of Essen-Duisburg, 45147 Essen, Germany
- Department of Ophthalmology, University of Essen-Duisburg, 45147 Essen, Germany
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2
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Bai G, Wei H, Li S. THE DIAGNOSTIC VALUE OF MULTISPECTRAL FUNDUS IMAGING IN HYPERTENSIVE RETINOPATHY. Retina 2024; 44:1092-1099. [PMID: 38320305 DOI: 10.1097/iae.0000000000004060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
PURPOSE To observe the diagnostic value of multispectral fundus imaging (MSI) in hypertensive retinopathy (HR). METHODS A total of 100 patients with HR were enrolled in this cross-sectional study, and all participants received fundus photography and MSI. Participants with severe HR received fundus fluorescein angiography (FFA). The diagnostic consistency between fundus photography and MSI in the diagnosis of HR was calculated. The sensitivity of MSI in the diagnosis of severe HR was calculated by comparison with FFA. Choroidal vascular index was calculated in patients with HR using MSI at 780 nm. RESULTS MSI and fundus photography were highly concordant in the diagnosis of HR with a Kappa value = 0.883. MSI had a sensitivity of 96% in diagnosing retinal hemorrhage, a sensitivity of 89.47% in diagnosing retinal exudation, a sensitivity of 100% in diagnosing vascular compression indentation, and a sensitivity of 96.15% in diagnosing retinal arteriosclerosis. The choroidal vascular index of the patients in the HR group was significantly lower than that of the control group, whereas there was no significant difference between the affected and fellow eyes. CONCLUSION As a noninvasive modality of observation, MSI may be a new tool for the diagnosis and assessment of HR.
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Affiliation(s)
- Guitao Bai
- Department of Ophthalmology, Zigong First People's Hospital, Zigong, China; and
| | - Hao Wei
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Shuangle Li
- Department of Ophthalmology, Zigong First People's Hospital, Zigong, China; and
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3
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Ning K, Bhuckory MB, Lo CH, Sendayen BE, Kowal TJ, Chen M, Bansal R, Chang KC, Vollrath D, Berbari NF, Mahajan VB, Hu Y, Sun Y. Cilia-associated wound repair mediated by IFT88 in retinal pigment epithelium. Sci Rep 2023; 13:8205. [PMID: 37211572 PMCID: PMC10200793 DOI: 10.1038/s41598-023-35099-3] [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: 12/06/2022] [Accepted: 05/12/2023] [Indexed: 05/23/2023] Open
Abstract
Primary cilia are conserved organelles that integrate extracellular cues into intracellular signals and are critical for diverse processes, including cellular development and repair responses. Deficits in ciliary function cause multisystemic human diseases known as ciliopathies. In the eye, atrophy of the retinal pigment epithelium (RPE) is a common feature of many ciliopathies. However, the roles of RPE cilia in vivo remain poorly understood. In this study, we first found that mouse RPE cells only transiently form primary cilia. We then examined the RPE in the mouse model of Bardet-Biedl Syndrome 4 (BBS4), a ciliopathy associated with retinal degeneration in humans, and found that ciliation in BBS4 mutant RPE cells is disrupted early during development. Next, using a laser-induced injury model in vivo, we found that primary cilia in RPE reassemble in response to laser injury during RPE wound healing and then rapidly disassemble after the repair is completed. Finally, we demonstrated that RPE-specific depletion of primary cilia in a conditional mouse model of cilia loss promoted wound healing and enhanced cell proliferation. In summary, our data suggest that RPE cilia contribute to both retinal development and repair and provide insights into potential therapeutic targets for more common RPE degenerative diseases.
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Affiliation(s)
- Ke Ning
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
| | - Mohajeet B Bhuckory
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
| | - Chien-Hui Lo
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
| | - Brent E Sendayen
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
- Palo Alto Veterans Administration, Palo Alto, CA, USA
| | - Tia J Kowal
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
| | - Ming Chen
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
| | - Ruchi Bansal
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Kun-Che Chang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Douglas Vollrath
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Vinit B Mahajan
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA, 94304, USA.
- Palo Alto Veterans Administration, Palo Alto, CA, USA.
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4
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Ahsanuddin S, Rios HA, Otero-Marquez O, Macanian J, Zhou D, Rich C, Rosen RB. Flavoprotein fluorescence elevation is a marker of mitochondrial oxidative stress in patients with retinal disease. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1110501. [PMID: 38983095 PMCID: PMC11182218 DOI: 10.3389/fopht.2023.1110501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/27/2023] [Indexed: 07/11/2024]
Abstract
Purpose Recent studies of glaucoma, age-related macular degeneration, and diabetic retinopathy have demonstrated that flavoprotein fluorescence (FPF) can be utilized non-invasively as an indicator of mitochondrial oxidative stress in the retina. However, a comprehensive assessment of the validity and reliability of FPF in differentiating between healthy and diseased eyes across multiple disease states is lacking. Here, we evaluate the sensitivity and specificity of FPF in discriminating between healthy and diseased eyes in four leading causes of visual impairment worldwide, one of which has not been previously evaluated using FPF. We also evaluate the association between FPF and visual acuity. Methods A total of 88 eyes [21 eyes of 21 unaffected controls, 20 eyes from 20 retinal vein occlusion (RVO) patients, 20 eyes from 20 diabetic retinopathy (DR) patients, 17 eyes from 17 chronic exudative age-related macular degeneration (exudative AMD) patients, and 10 eyes from 10 central serous retinopathy (CSR) patients] were included in the present cross-sectional observational study. Eyes were imaged non-invasively using a specially configured fundus camera OcuMet Beacon® (OcuSciences, Ann Arbor, MI). The macula was illuminated using a narrow bandwidth blue light (455 - 470 nm) and fluorescence was recorded using a narrow notch filter to match the peak emission of flavoproteins from 520 to 540 nm. AUROC analysis was used to determine the sensitivity of FPF in discriminating between diseased eyes and healthy eyes. Nonparametric Kruskal-Wallis Tests with post-hoc Mann Whitney U tests with the Holm-Bonferroni correction were performed to assess differences in FPF intensity, FPF heterogeneity, and best corrected visual acuity (BCVA) between the five groups. Spearman rank correlation coefficients were calculated to assess the relationship between FPF and BCVA. Results AUROC analysis indicated that FPF intensity is highly sensitive for detecting disease, particularly for exudative AMD subjects (0.989; 95% CI = 0.963 - 1.000, p=3.0 x 107). A significant difference was detected between the FPF intensity, FPF heterogeneity, and BCVA in all four disease states compared to unaffected controls (Kruskal-Wallis Tests, p = 1.06 x 10-8, p = 0.002, p = 5.54 x 10-8, respectively). Compared to healthy controls, FPF intensity values were significantly higher in RVO, DR, exudative AMD, and CSR (p < 0.001, p < 0.001, p < 0.001, and p = 0.001, respectively). Spearman rank correlation coefficient between FPF intensity and BCVA was ρ = 0.595 (p = 9.62 x 10-10). Conclusions Despite variations in structural retinal findings, FPF was found to be highly sensitive for detecting retinal disease. Significant FPF elevation were seen in all four disease states, with the exudative AMD patients exhibiting the highest FPF values compared to DR, CSR, and RVO subjects. This is consistent with the hypothesis that there is elevated oxidative stress in all of these conditions as previously demonstrated by blood studies. FPF intensity is moderately correlated with the late-in disease-marker BCVA, which suggests that the degree of FPF elevation can be used as a metabolic indicator of disease severity.
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Affiliation(s)
- Sofia Ahsanuddin
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, United States
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Hernan A. Rios
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, United States
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Oscar Otero-Marquez
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, United States
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Jason Macanian
- Department of Medical Education, New York Medical College, Valhalla, NY, United States
| | - Davis Zhou
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, United States
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Collin Rich
- OcuSciences Inc., Ann Arbor, MI, United States
| | - Richard B. Rosen
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, United States
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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5
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Gullapalli VK, Zarbin MA. New Prospects for Retinal Pigment Epithelium Transplantation. Asia Pac J Ophthalmol (Phila) 2022; 11:302-313. [PMID: 36041145 DOI: 10.1097/apo.0000000000000521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/28/2022] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT Retinal pigment epithelium (RPE) transplants rescue photoreceptors in selected animal models of retinal degenerative disease. Early clinical studies of RPE transplants as treatment for age-related macular degeneration (AMD) included autologous and allogeneic transplants of RPE suspensions and RPE sheets for atrophic and neovascular complications of AMD. Subsequent studies explored autologous RPE-Bruch membrane-choroid transplants in patients with neovascular AMD with occasional marked visual benefit, which establishes a rationale for RPE transplants in late-stage AMD. More recent work has involved transplantation of autologous and allogeneic stem cell-derived RPE for patients with AMD and those with Stargardt disease. These early-stage clinical trials have employed RPE suspensions and RPE monolayers on biocompatible scaffolds. Safety has been well documented, but evidence of efficacy is variable. Current research involves development of better scaffolds, improved modulation of immune surveillance, and modification of the extracellular milieu to improve RPE survival and integration with host retina.
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Affiliation(s)
| | - Marco A Zarbin
- Iinstitute of Ophthalmology and visual Science, Rutgers-New Jersey Medical School, Rutgers University, Newark, NJ, US
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6
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Zauhar R, Biber J, Jabri Y, Kim M, Hu J, Kaplan L, Pfaller AM, Schäfer N, Enzmann V, Schlötzer-Schrehardt U, Straub T, Hauck SM, Gamlin PD, McFerrin MB, Messinger J, Strang CE, Curcio CA, Dana N, Pauly D, Grosche A, Li M, Stambolian D. As in Real Estate, Location Matters: Cellular Expression of Complement Varies Between Macular and Peripheral Regions of the Retina and Supporting Tissues. Front Immunol 2022; 13:895519. [PMID: 35784369 PMCID: PMC9240314 DOI: 10.3389/fimmu.2022.895519] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 05/11/2022] [Indexed: 01/02/2023] Open
Abstract
The cellular events that dictate the initiation of the complement pathway in ocular degeneration, such as age-related macular degeneration (AMD), is poorly understood. Using gene expression analysis (single cell and bulk), mass spectrometry, and immunohistochemistry, we dissected the role of multiple retinal and choroidal cell types in determining the complement homeostasis. Our scRNA-seq data show that the cellular response to early AMD is more robust in the choroid, particularly in fibroblasts, pericytes and endothelial cells. In late AMD, complement changes were more prominent in the retina especially with the expression of the classical pathway initiators. Notably, we found a spatial preference for these differences. Overall, this study provides insights into the heterogeneity of cellular responses for complement expression and the cooperation of neighboring cells to complete the pathway in healthy and AMD eyes. Further, our findings provide new cellular targets for therapies directed at complement.
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Affiliation(s)
- Randy Zauhar
- Department of Chemistry and Biochemistry, The University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Josef Biber
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Yassin Jabri
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
| | - Mijin Kim
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Jian Hu
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Lew Kaplan
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Anna M. Pfaller
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - 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
| | - Volker Enzmann
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | | | - Tobias Straub
- Bioinformatics Unit, Biomedical Center, Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany
| | - Stefanie M. Hauck
- Metabolomics and Proteomics Core and Research Unit Protein Science, Helmholtz-Zentrum München, Neuherberg, Germany
| | - Paul D. Gamlin
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Michael B. McFerrin
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jeffrey Messinger
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Christianne E. Strang
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Nicholas Dana
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Diana Pauly
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
- Experimental Ophthalmology, University of Marburg, Marburg, Germany
| | - Antje Grosche
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Mingyao Li
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Dwight Stambolian
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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7
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Khoobehi B, Wafapoor H, Eaton A, Liu R, Firn K, Kubilay T. Noninvasive Measurement of Oxygen Saturation in Human Retinal Blood Vessels and Tissues With Multispectral Confocal Imaging. Ophthalmic Surg Lasers Imaging Retina 2022; 53:275-283. [PMID: 35575738 DOI: 10.3928/23258160-20220420-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE Proof of concept for the first system of noninvasive human retinal vessel and tissue oxygenation measurement in axial and radial directions. MATERIALS AND METHODS A confocal imaging system capable of calculating and mapping relative retinal blood oxygenation in radial and axial directions from three eyes of two healthy subjects was built. The relationship between oxygenation and retinal depth in vivo was analyzed to illustrate application of this novel system. RESULTS The system shows capacity for measuring oxygenation along retinal depth for the first time. (1) Arteriovenous oxygenation difference decreases with blood vessel diameter. (2) Artery-tissue oxygenation difference is greater than vein-tissue oxygenation difference in the same region. (3) Intravascular-extravascular oxygenation difference decreases with blood vessel diameter. (4) Oxygenation data reported with a 95% CI are as follows: A1 91.5% ± 18.2%, V1 32.8% ± 18.6%, A2 97.3% ± 17.8%, V2 64.4% ± 11.2%, A3 73.2% ± 19.1%, V3 52.9% ± 15.3%, and Tissue 56.6% ± 00.4%. CONCLUSION This article demonstrates proof of concept for retinal oxygenation calculation in radial and axial dimensions for the first time. Initial results provide biological validity to this method. Future aims include further characterization of this system's results in healthy subjects and subsequent comparison of oxygenation between diseased and healthy retinae. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:275-283.].
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Huang D, Xu C, Guo R, Ji J, Liu W. Anterior lens capsule: biomechanical properties and biomedical engineering perspectives. Acta Ophthalmol 2021; 99:e302-e309. [PMID: 32914585 DOI: 10.1111/aos.14600] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 07/19/2020] [Accepted: 08/01/2020] [Indexed: 12/13/2022]
Abstract
Anterior lens capsule, as the thickest basement membrane in the body, has its unique physiology characteristics. In ophthalmology, many attempts have been made to culture different kinds of cells including iris pigment epithelial cells, retinal pigment epithelial cells, corneal epithelium and endothelium cells, trabecular meshwork cells etc and anterior lens capsule has been confirmed to be served as an excellent scaffold for the growth and expansion of different ocular cells. Furthermore, anterior lens capsule also has unique potential in gestation evaluation and the treatment of various ocular diseases, including corneal ulcer, glaucoma, age-related macular degeneration and macular hole, etc. Here, we provide an overview of the biomechanical properties and biomedical engineering perspectives of anterior lens capsule.
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Affiliation(s)
- Dandan Huang
- Department of Ophthalmology Taihe Hospital Hubei University of Medicine Shiyan China
| | - Chenjia Xu
- Tianjin Key Laboratory of Retinal Functions and Diseases Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science Eye Institute and School of Optometry Tianjin Medical University Eye Hospital Tianjin China
| | - Ruru Guo
- Tianjin Key Laboratory of Retinal Functions and Diseases Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science Eye Institute and School of Optometry Tianjin Medical University Eye Hospital Tianjin China
| | - Jian Ji
- Tianjin Key Laboratory of Retinal Functions and Diseases Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science Eye Institute and School of Optometry Tianjin Medical University Eye Hospital Tianjin China
| | - Wei Liu
- Tianjin Key Laboratory of Retinal Functions and Diseases Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science Eye Institute and School of Optometry Tianjin Medical University Eye Hospital Tianjin China
- Department of Ophthalmology University Medical Center Groningen University of Groningen Groningen The Netherlands
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9
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Hsu XL, Wu LC, Hsieh JY, Huang YY. Nanoparticle-Hydrogel Composite Drug Delivery System for Potential Ocular Applications. Polymers (Basel) 2021; 13:polym13040642. [PMID: 33670014 PMCID: PMC7927131 DOI: 10.3390/polym13040642] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 01/05/2023] Open
Abstract
Intravitreal injections are clinically established procedures in the treatment of posterior eye diseases, such as wet age-related macular degeneration (wet AMD) which requires monthly intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) protein drugs that can lead to complications due to frequent dosing. In this study, we designed a composite drug delivery system (DDS) consisting of drug-loaded poly (lactide–co–glycolide) (PLGA) nanoparticles and a chemically crosslinked hyaluronan hydrogel to reduce the dosing frequency. The morphology, size, composition, and drug loading efficiency of the prepared nanoparticles were characterized. The properties of the modified hyaluronan polymers used were also examined. The degree of swelling/degradation and controlled release ability of the hyaluronan hydrogel and the composite DDS were identified using bovine serum albumin (BSA) as a model drug. The results show that this system can retain 75% of its wet weight without losing its integrity and release the model drug at the rate of 0.4 μg/day for more than two months under physiological conditions. In addition, the nanoparticulate formulation of the system can further improve bioavailability of the drugs by penetrating deep into the retinal layers. In conclusion, the proposed composite DDS is easily prepared with biocompatible materials and is promising for providing the sustained release of the protein drugs as a better treatment for ocular neovascular diseases like wet AMD.
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Affiliation(s)
- Xuan-Ling Hsu
- Department of Biomedical Engineering, National Taiwan University, Taipei 10051, Taiwan; (X.-L.H.); (J.-Y.H.)
| | - Lien-Chen Wu
- Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan;
- Department of Orthopedics, Shuang Ho Hospital, Taipei Medical University, Taipei 23561, Taiwan
| | - Jui-Yang Hsieh
- Department of Biomedical Engineering, National Taiwan University, Taipei 10051, Taiwan; (X.-L.H.); (J.-Y.H.)
| | - Yi-You Huang
- Department of Biomedical Engineering, National Taiwan University, Taipei 10051, Taiwan; (X.-L.H.); (J.-Y.H.)
- Department of Biomedical Engineering, National Taiwan University Hospital, Taipei 10051, Taiwan
- Correspondence:
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10
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Hermenean A, Trotta MC, Gharbia S, Hermenean AG, Peteu VE, Balta C, Cotoraci C, Gesualdo C, Rossi S, Gherghiceanu M, D'Amico M. Changes in Retinal Structure and Ultrastructure in the Aged Mice Correlate With Differences in the Expression of Selected Retinal miRNAs. Front Pharmacol 2021; 11:593514. [PMID: 33519453 PMCID: PMC7838525 DOI: 10.3389/fphar.2020.593514] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/29/2020] [Indexed: 12/19/2022] Open
Abstract
Age and gender are two important factors that may influence the function and structure of the retina and its susceptibility to retinal diseases. The aim of this study was to delineate the influence that biological sex and age exert on the retinal structural and ultrastructural changes in mice and to identify the age-related miRNA dysregulation profiles in the retina by gender. Experiments were undertaken on male and female Balb/c aged 24 months (approximately 75–85 years in humans) compared to the control (3 months). The retinas were analyzed by histology, transmission electron microscopy, and age-related miRNA expression profile analysis. Retinas of both sexes showed a steady decline in retinal thickness as follows: photoreceptor (PS) and outer layers (p < 0.01 for the aged male vs. control; p < 0.05 for the aged female vs. control); the inner retinal layers were significantly affected by the aging process in the males (p < 0.01) but not in the aged females. Electron microscopy revealed more abnormalities which involve the retinal pigment epithelium (RPE) and Bruch’s membrane, outer and inner layers, vascular changes, deposits of amorphous materials, and accumulation of lipids or lipofuscins. Age-related miRNAs, miR-27a-3p (p < 0.01), miR-27b-3p (p < 0.05), and miR-20a-5p (p < 0.05) were significantly up-regulated in aged male mice compared to the controls, whereas miR-20b-5p was significantly down-regulated in aged male (p < 0.05) and female mice (p < 0.05) compared to the respective controls. miR-27a-3p (5.00 fold; p < 0.01) and miR-27b (7.58 fold; p < 0.01) were significantly up-regulated in aged male mice vs. aged female mice, whereas miR-20b-5p (−2.10 fold; p < 0.05) was significantly down-regulated in aged male mice vs. aged female mice. Interestingly, miR-27a-3p, miR-27b-3p, miR-20a-5p, and miR-20b-5p expressions significantly correlated with the thickness of the retinal PS layer (p < 0.01), retinal outer layers (p < 0.01), and Bruch’s membrane (p < 0.01). Our results showed that biological sex can influence the structure and function of the retina upon aging, suggesting that this difference may be underlined by the dysregulation of age-related mi-RNAs.
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Affiliation(s)
- Anca Hermenean
- "Aurel Ardelean" Institute of Life Sciences, Vasile Goldis Western University of Arad, Arad, Romania.,Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania
| | - Maria Consiglia Trotta
- Section of Pharmacology, Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Sami Gharbia
- "Aurel Ardelean" Institute of Life Sciences, Vasile Goldis Western University of Arad, Arad, Romania.,Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania
| | | | | | - Cornel Balta
- "Aurel Ardelean" Institute of Life Sciences, Vasile Goldis Western University of Arad, Arad, Romania
| | - Coralia Cotoraci
- Faculty of Medicine, Vasile Goldis Western University of Arad, Arad, Romania
| | - Carlo Gesualdo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Settimio Rossi
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Mihaela Gherghiceanu
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.,Victor Babes National Institute of Pathology, Bucharest, Romania
| | - Michele D'Amico
- Section of Pharmacology, Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
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11
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Huang X, Chau Y. Enhanced Delivery of siRNA to Retinal Ganglion Cells by Intravitreal Lipid Nanoparticles of Positive Charge. Mol Pharm 2020; 18:377-385. [PMID: 33295773 DOI: 10.1021/acs.molpharmaceut.0c00992] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
RNAi therapy has been developed and explored for treating retinal conditions since last decades. The progression of retinal diseases including the age-related macular degeneration and glaucoma is associated with the malfunction of specific retinal cells. Therefore, to deliver therapeutic RNAi to selective retinal tissues with desired gene downregulation is crucial for the treatment of retinal diseases via RNAi therapy. Lipid-based nanoparticles are potent delivery vectors for RNAi therapeutics to achieve high gene silencing efficiency. The surface charge has been demonstrated to affect the intraocular behaviors and retinal distribution of intravitreally administered lipid nanoparticles (LNPs), which could subsequently affect the gene knockdown efficiency in specific retinal layers. Here, we evaluated three charged LNPs for their ability to deliver siRNA and facilitate gene downregulation both in vitro and in vivo. LNPs with different surface charges ranging from neutral to positive (5-34 mV) were successfully formulated. All types of charged LNPs managed gene knockdown in both mammalian cell line and primary neurons. At 48 h post intravitreal injection, neutral LNPs (6.2 mV) and mildly positive LNPs (15.9 mV) mediated limited retinal gene suppression (<10%) and the more positive LNPs (31.2 mV) led to ∼25% gene suppression in the retinal ganglion cell (RGC) layer. No gene silencing in the retinal pigmented epithelium layer was facilitated by any LNPs independent of the charges. In summary, this study has shown that positive LNPs with an optimized charge managed specific gene downregulation in the RGC layer. These RNAi carriers hold potential for the treatment of RGC-associated retinal diseases.
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Affiliation(s)
- Xiaonan Huang
- Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon 999077, Hong Kong, China
| | - Ying Chau
- Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon 999077, Hong Kong, China
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12
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Ozcaliskan S, Balci S, Yenerel NM. Choroidal vascularity index determined by binarization of enhanced depth imaging optical coherence tomography images in eyes with intermediate age-related macular degeneration. Eur J Ophthalmol 2020; 30:1512-1518. [DOI: 10.1177/1120672120919341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Purpose To evaluate choroidal structural changes in patients with intermediate age-related macular degeneration using choroidal vascularity index. Methods The eyes of patients with intermediate age-related macular degeneration and controls were evaluated with enhanced depth imaging optical coherence tomography images. Subfoveal choroidal area was segmented into luminal area and stromal area by the binarization technique on enhanced depth imaging optical coherence tomography images using ImageJ software. Choroidal vascularity index was defined as the ratio of luminal area to total circumscribed subfoveal choroidal area. Results Fifty-seven eyes with intermediate age-related macular degeneration and 60 healthy control eyes were included in the study. The choroidal vascularity index was computed as 59.53% ± 4.9% in the intermediate age-related macular degeneration group and as 62.7% ± 4.3% in the control group ( p = 0.002). Patients with age-related macular degeneration showed significantly lower values of stromal area and higher values of luminal area compared to control subjects (0.51 ± 0.22 vs 0.87 ± 0.21, p < 0.001 and 0.74 ± 0.22 vs 0.52 ± 0.18, p < 0.001, respectively). Conclusion Eyes with intermediate age-related macular degeneration demonstrated reduced choroidal vascularity index compared to healthy eyes. Choroidal vascularity index seems to be a potential non-invasive quantitative method for studying structural changes of the choroid in patients with intermediate age-related macular degeneration.
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Affiliation(s)
- Sehnaz Ozcaliskan
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
| | - Sevcan Balci
- University of Health Sciences, Haydarpaşa Numune Training and Research Hospital, Istanbul, Turkey
| | - Nursal Melda Yenerel
- University of Health Sciences, Haydarpaşa Numune Training and Research Hospital, Istanbul, Turkey
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13
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Xu XZ, Tang Y, Cheng LB, Yao J, Jiang Q, Li KR, Zhen YF. Targeting Keap1 by miR-626 protects retinal pigment epithelium cells from oxidative injury by activating Nrf2 signaling. Free Radic Biol Med 2019; 143:387-396. [PMID: 31446056 DOI: 10.1016/j.freeradbiomed.2019.08.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/09/2019] [Accepted: 08/21/2019] [Indexed: 11/19/2022]
Abstract
Activation of the NF-E2-related factor 2 (Nrf2) cascade can offer significant protection against oxidative stress in retinal pigment epithelium (RPE) cells. Here, we identified a novel kelch-like ECH-associated protein 1 (Keap1)-targeting microRNA, microRNA-626 (miR-626) that activates Nrf2 signaling. In ARPE-19 cells and primary human RPE cells, ectopic overexpression of miR-626 targeting the 3'-UTR (3'-untranslated region) of Keap1 downregulated its expression, promoting Nrf2 protein stabilization and nuclear translocation, leading to expression of ARE-dependent genes (HO1, NOQ1 and GCLC). Functional studies showed that miR-626 protected RPE cells from hydrogen peroxide (H2O2)-induced oxidative injury. Conversely, miR-626 inhibition induced Keap1 upregulation and Nrf2 cascade inhibition, exacerbating oxidative injury in RPE cells. Further studies demonstrated that miR-626 was ineffective in Keap1-knockout or Nrf2-knockout RPE cells. Importantly, miR-626 also activated Keap1-Nrf2 signaling cascade in human lens epithelial cells (HLECs) and primary human retinal ganglion cells (RGCs), providing protection from H2O2. At last, we show that plasma miR-626 levels are significantly downregulated in age-related macular degeneration (AMD) patients than those in the healthy donors. We conclude that targeting Keap1 by miR-626 protects RPE cells and other ophthalmic cells from oxidative injury via activation of Nrf2 signaling cascade.
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Affiliation(s)
- Xiang-Zhong Xu
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Yu Tang
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Li-Bo Cheng
- Department of Ophthalmology, Wuxi Second Hospital, Nanjing Medical University, Wu'xi, China
| | - Jin Yao
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Qin Jiang
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China.
| | - Ke-Ran Li
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China.
| | - Yun-Fang Zhen
- The Center of Diagnosis and Treatment for Children's Bone Diseases, The Children's Hospital Affiliated to Soochow University, Suzhou, China.
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14
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CFH exerts anti-oxidant effects on retinal pigment epithelial cells independently from protecting against membrane attack complex. Sci Rep 2019; 9:13873. [PMID: 31554875 PMCID: PMC6761137 DOI: 10.1038/s41598-019-50420-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/20/2019] [Indexed: 12/03/2022] Open
Abstract
Age Related Macular Degeneration (AMD) is the first cause of social blindness in people aged over 65 leading to atrophy of retinal pigment epithelial cells (RPE), photoreceptors and choroids, eventually associated with choroidal neovascularization. Accumulation of undigested cellular debris within RPE cells or under the RPE (Drusen), oxidative stress and inflammatory mediators contribute to the RPE cell death. The major risk to develop AMD is the Y402H polymorphism of complement factor H (CFH). CFH interacting with oxidized phospholipids on the RPE membrane modulates the functions of these cells, but the exact role of CFH in RPE cell death and survival remain poorly understood. The aim of this study was to analyze the potential protective mechanism of CFH on RPE cells submitted to oxidative stress. Upon exposure to oxidized lipids 4-HNE (4-hydroxy-2-nonenal) derived from photoreceptors, both the human RPE cell line ARPE-19 and RPE cells derived from human induced pluripotent stem cells were protected from death only in the presence of the full length human recombinant CFH in the culture medium. This protective effect was independent from the membrane attack complex (MAC) formation. CFH maintained RPE cells tight junctions’ structure and regulated the caspase dependent apoptosis process. These results demonstrated the CFH anti-oxidative stress functions independently of its capacity to inhibit MAC formation.
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15
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Ultrastructural Changes and Expression of PCNA and RPE65 in Sodium Iodate-Induced Acute Retinal Pigment Epithelium Degeneration Model. Neurochem Res 2018; 43:1010-1019. [DOI: 10.1007/s11064-018-2508-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 03/14/2018] [Accepted: 03/16/2018] [Indexed: 01/30/2023]
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16
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Heo JH, Yoon JA, Ahn EK, Kim H, Urm SH, Oak CO, Yu BC, Lee SJ. Intraperitoneal administration of adipose tissue-derived stem cells for the rescue of retinal degeneration in a mouse model via indigenous CNTF up-regulation by IL-6. J Tissue Eng Regen Med 2017; 12:e1370-e1382. [PMID: 28715614 DOI: 10.1002/term.2522] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 04/05/2017] [Accepted: 06/20/2017] [Indexed: 12/21/2022]
Abstract
As the world's population begins to age, retinal degeneration is an increasing problem, and various treatment modalities are being developed. However, there have been no therapies for degenerative retinal conditions that are not characterized by neovascularization. We investigated whether transplantation of mouse adipose tissue-derived stem cells (mADSC) into the intraperitoneal space has a rescue effect on NaIO3 -induced retinal degeneration in mice. In this study, mADSC transplantation recovered visual function and preserved the retinal outer layer structure compared to the control group without any integration of mADSC into the retina. Moreover, endogenous ciliary neurotrophic factor (CNTF) was elevated in the retinas of mADSC-treated mice. We found that lipopolysaccharide (LPS) or LPS-stimulated monocyte supernatant induced the secretion of granulocyte colony stimulating factor (GCSF), CD54, CXCL10, interleukin-6 (IL-6), and CCL5 from the mADSC by cytokine array. Network inference was conducted to investigate signaling networks related to CNTF regulation. Based on bioinformatics data, the expression of IL-6 was related to the expression of CNTF. Additionally, intravitreal injection of IL-6 in rats produced up-regulation of endogenous CNTF in the retina. mADSC had a rescue effect on retinal degeneration through the up-regulation of endogenous CNTF by IL-6. Thus, transplantation of mADSC could be a potential treatment option for retinal degeneration.
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Affiliation(s)
- Jeong Hoon Heo
- Department of Molecular Biology and Immunology, College of Medicine, Kosin University, Pusan, Korea.,Institute for Medicine, College of Medicine, Kosin University, Pusan, Korea
| | - Jung Ae Yoon
- Department of Dental Hygiene, Dong Ju College, Pusan, Korea
| | - Eun Kyung Ahn
- Department of Biological Science, College of Natural Science, Dong-A University, Pusan, Korea
| | - Hyun Kim
- Department of Anatomy, College of Medicine, Kosin University, Pusan, Korea
| | - Sang Hwa Urm
- Department of Preventive Medicine, Inje University College of Medicine, Pusan, Korea
| | - Chul Oh Oak
- Department of Internal Medicine, College of Medicine, Kosin University, Pusan, Korea
| | - Byeng Chul Yu
- Department of Preventive Medicine, College of Medicine, Kosin University, Pusan, Korea
| | - Sang Joon Lee
- Institute for Medicine, College of Medicine, Kosin University, Pusan, Korea.,Department of Ophthalmology, College of Medicine, Kosin University, Pusan, Korea
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17
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Ko JA, Sotani Y, Ibrahim DG, Kiuchi Y. Role of macrophage migration inhibitory factor (MIF) in the effects of oxidative stress on human retinal pigment epithelial cells. Cell Biochem Funct 2017; 35:426-432. [PMID: 28906008 DOI: 10.1002/cbf.3292] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 07/31/2017] [Accepted: 08/10/2017] [Indexed: 12/27/2022]
Abstract
Proliferative vitreoretinopathy (PVR) is the major cause of treatment failure in individuals who undergo surgery for retinal detachment. The epithelial-mesenchymal transition (EMT) in retinal pigment epithelium (RPE) cells contributes to the pathogenesis of PVR. Oxidative stress is thought to play a role in the progression of retinal diseases including PVR. We have now examined the effects of oxidative stress on the EMT and related processes in the human RPE cell line. We found that H2 O2 induced the contraction of RPE cells in a three-dimensional collagen gel. Analysis of a cytokine array revealed that H2 O2 specifically increased the release of macrophage migration inhibitory factor (MIF) from RPE cells. Reverse transcription-polymerase chain reaction and immunoblot analyses showed that H2 O2 increased the expression of MIF in RPE cells. Immunoblot and immunofluorescence analyses revealed that H2 O2 upregulated the expression of α-SMA and vimentin and downregulated that of ZO-1 and N-cadherin. Consistent with these observations, the transepithelial electrical resistance of cell was reduced by exposure to H2 O2 . The effects of oxidative stress on EMT-related and junctional protein expression as well as on transepithelial electrical resistance were inhibited by antibodies to MIF, but they were not mimicked by treatment with recombinant MIF. Finally, analysis with a profiling array for mitogen-activated protein kinase signalling revealed that H2 O2 specifically induced the phosphorylation of p38 mitogen-activated protein kinase. Our results thus suggest that MIF may play a role in induction of the EMT and related processes by oxidative stress in RPE cells and that it might thereby contribute to the pathogenesis of PVR. Proliferative vitreoretinopathy is a major complication of rhegmatogenous retinal detachment, and both oxidative stress and induction of the EMT in RPE cells are thought to contribute to the pathogenesis of this condition. We have now examined the effects of oxidative stress on the EMT and related processes in the human RPE cell line ARPE19. Our results thus implicate MIF in induction of the EMT and related processes by oxidative stress in RPE cells and the regulated expression of EMT markers. They further suggest that MIF may play an important role in the pathogenesis of PVR.
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Affiliation(s)
- Ji-Ae Ko
- Department of Ophthalmology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
| | - Yasuyuki Sotani
- Department of Ophthalmology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
| | - Diah Gemala Ibrahim
- Department of Ophthalmology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
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18
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Kurihara T, Westenskow PD, Gantner ML, Usui Y, Schultz A, Bravo S, Aguilar E, Wittgrove C, Friedlander MS, Paris LP, Chew E, Siuzdak G, Friedlander M. Hypoxia-induced metabolic stress in retinal pigment epithelial cells is sufficient to induce photoreceptor degeneration. eLife 2016; 5. [PMID: 26978795 PMCID: PMC4848091 DOI: 10.7554/elife.14319] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/11/2016] [Indexed: 12/24/2022] Open
Abstract
Photoreceptors are the most numerous and metabolically demanding cells in the retina. Their primary nutrient source is the choriocapillaris, and both the choriocapillaris and photoreceptors require trophic and functional support from retinal pigment epithelium (RPE) cells. Defects in RPE, photoreceptors, and the choriocapillaris are characteristic of age-related macular degeneration (AMD), a common vision-threatening disease. RPE dysfunction or death is a primary event in AMD, but the combination(s) of cellular stresses that affect the function and survival of RPE are incompletely understood. Here, using mouse models in which hypoxia can be genetically triggered in RPE, we show that hypoxia-induced metabolic stress alone leads to photoreceptor atrophy. Glucose and lipid metabolism are radically altered in hypoxic RPE cells; these changes impact nutrient availability for the sensory retina and promote progressive photoreceptor degeneration. Understanding the molecular pathways that control these responses may provide important clues about AMD pathogenesis and inform future therapies. DOI:http://dx.doi.org/10.7554/eLife.14319.001 Cells use a sugar called glucose as fuel to provide energy for many essential processes. The light-sensing cells in the eye, known as photoreceptors, need tremendous amounts of glucose, which they receive from the blood with the help of neighboring cells called retinal pigment epithelium (RPE) cells. Without a reliable supply of this sugar, the photoreceptors die and vision is lost. As we age, we are at greater risk of vision loss because RPE cells become less efficient at transporting glucose and our blood vessels shrink so that the photoreceptors may become starved of glucose. To prevent age-related vision loss, we need new strategies to keep blood vessels and RPE cells healthy. However, it was not clear exactly how RPE cells supply photoreceptors with glucose, and what happens when blood supplies are reduced. To address this question, Kurihara, Westenskow et al. used genetically modified mice to investigate how cells in the eye respond to starvation. The experiments show that when nutrients are scarce the RPE cells essentially panic, radically change their diet, and become greedy. That is to say that they double in size and begin burning fuel faster while also stockpiling extra sugar and fat for later use. In turn, the photoreceptors don’t get the energy they need and so they slowly stop working and die. Kurihara, Westenskow et al. also show that there is a rapid change in the way in which sugar and fat are processed in the eye during starvation. Learning how to prevent these changes in patients with age-related vision loss could protect their photoreceptors from starvation and death. The next step following on from this research is to design drugs to improve the supply of glucose and nutrients to the photoreceptors by repairing aging blood vessels and/or preventing RPE cells from stockpiling glucose for themselves. DOI:http://dx.doi.org/10.7554/eLife.14319.002
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Affiliation(s)
- Toshihide Kurihara
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
| | - Peter D Westenskow
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States.,The Lowy Medical Research Institute, La Jolla, United States
| | - Marin L Gantner
- The Lowy Medical Research Institute, La Jolla, United States
| | - Yoshihiko Usui
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
| | - Andrew Schultz
- Center for Metabolomics, The Scripps Research Institute, La Jolla, United States
| | - Stephen Bravo
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
| | - Edith Aguilar
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
| | - Carli Wittgrove
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
| | - Mollie Sh Friedlander
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
| | - Liliana P Paris
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
| | - Emily Chew
- National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Gary Siuzdak
- Center for Metabolomics, The Scripps Research Institute, La Jolla, United States
| | - Martin Friedlander
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, United States
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19
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Connexin43 in retinal injury and disease. Prog Retin Eye Res 2016; 51:41-68. [DOI: 10.1016/j.preteyeres.2015.09.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/25/2015] [Accepted: 09/27/2015] [Indexed: 12/26/2022]
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20
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Tuo J, Wang Y, Cheng R, Li Y, Chen M, Qiu F, Qian H, Shen D, Penalva R, Xu H, Ma JX, Chan CC. Wnt signaling in age-related macular degeneration: human macular tissue and mouse model. J Transl Med 2015; 13:330. [PMID: 26476672 PMCID: PMC4609061 DOI: 10.1186/s12967-015-0683-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 09/29/2015] [Indexed: 01/02/2023] Open
Abstract
Background The wingless-type MMTV integration site (Wnt) signaling is a group of signal transduction pathways. In canonical Wnt pathway, Wnt ligands bind to low-density lipoprotein receptor-related protein 5 or 6 (LRP5 or LRP6), resulting in phosphorylation and activation of the receptor. We hypothesize that canonical Wnt pathway plays a role in the retinal lesion of age-related macular degeneration (AMD), a leading cause of irreversible central visual loss in elderly. Methods We examined LRP6 phosphorylation and Wnt signaling cascade in human retinal sections and plasma kallistatin, an endogenous inhibitor of the Wnt pathway in AMD patients and non-AMD subjects. We also used the Ccl2−/−/Cx3cr1−/−/rd8 and Ccl2−/−/Cx3cr1gfp/gfp mouse models with AMD-like retinal degeneration to further explore the involvement of Wnt signaling activation in the retinal lesions in those models and to preclinically evaluate the role of Wnt signaling suppression as a potential therapeutic option for AMD. Results We found higher levels of LRP6 (a key Wnt signaling receptor) protein phosphorylation and transcripts of the Wnt pathway-targeted genes, as well as higher beta-catenin protein in AMD macula compared to controls. Kallistatin was decreased in the plasma of AMD patients. Retinal non-phosphorylated-β-catenin and phosphorylated-LRP6 were higher in Ccl2−/−/Cx3cr1−/−/rd8 mice than that in wild type. Intravitreal administration of an anti-LRP6 antibody slowed the progression of retinal lesions in Ccl2−/−/Cx3cr1−/−/rd8 and Ccl2−/−/Cx3cr1gfp/gfp mice. Electroretinography of treated eyes exhibited larger amplitudes compared to controls in both mouse models. A2E, a retinoid byproduct associated with AMD was lower in the treated eyes of Ccl2−/−/Cx3cr1−/−/rd8 mice. Anti-LRP6 also suppressed the expression of Tnf-α and Icam-1 in Ccl2−/−/Cx3cr1−/−/rd8 retinas. Conclusions Wnt signaling may be disturbed in AMD patients, which could contribute to the retinal inflammation and increased A2E levels found in AMD. Aberrant activation of canonical Wnt signaling might also contribute to the focal retinal degenerative lesions of mouse models with Ccl2 and Cx3cr1 deficiency, and intravitreal administration of anti-LRP6 antibody could be beneficial by deactivating the canonical Wnt pathway. Electronic supplementary material The online version of this article (doi:10.1186/s12967-015-0683-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jingsheng Tuo
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
| | - Yujuan Wang
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
| | - Rui Cheng
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Mei Chen
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.
| | - Fangfang Qiu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Defen Shen
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
| | - Rosana Penalva
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.
| | - Heping Xu
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Chi-Chao Chan
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
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21
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Biesemeier A, Yoeruek E, Eibl O, Schraermeyer U. Iron accumulation in Bruch's membrane and melanosomes of donor eyes with age-related macular degeneration. Exp Eye Res 2015; 137:39-49. [DOI: 10.1016/j.exer.2015.05.019] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 05/11/2015] [Accepted: 05/26/2015] [Indexed: 02/07/2023]
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22
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Wigg JP, Zhang H, Yang D. A Quantitative and Standardized Method for the Evaluation of Choroidal Neovascularization Using MICRON III Fluorescein Angiograms in Rats. PLoS One 2015; 10:e0128418. [PMID: 26024231 PMCID: PMC4449229 DOI: 10.1371/journal.pone.0128418] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/27/2015] [Indexed: 01/18/2023] Open
Abstract
Introduction In-vivo imaging of choroidal neovascularization (CNV) has been increasingly recognized as a valuable tool in the investigation of age-related macular degeneration (AMD) in both clinical and basic research applications. Arguably the most widely utilised model replicating AMD is laser generated CNV by rupture of Bruch’s membrane in rodents. Heretofore CNV evaluation via in-vivo imaging techniques has been hamstrung by a lack of appropriate rodent fundus camera and a non-standardised analysis method. The aim of this study was to establish a simple, quantifiable method of fluorescein fundus angiogram (FFA) image analysis for CNV lesions. Methods Laser was applied to 32 Brown Norway Rats; FFA images were taken using a rodent specific fundus camera (Micron III, Phoenix Laboratories) over 3 weeks and compared to conventional ex-vivo CNV assessment. FFA images acquired with fluorescein administered by intraperitoneal injection and intravenous injection were compared and shown to greatly influence lesion properties. Utilising commonly used software packages, FFA images were assessed for CNV and chorioretinal burns lesion area by manually outlining the maximum border of each lesion and normalising against the optic nerve head. Net fluorescence above background and derived value of area corrected lesion intensity were calculated. Results CNV lesions of rats treated with anti-VEGF antibody were significantly smaller in normalised lesion area (p<0.001) and fluorescent intensity (p<0.001) than the PBS treated control two weeks post laser. The calculated area corrected lesion intensity was significantly smaller (p<0.001) in anti-VEGF treated animals at 2 and 3 weeks post laser. The results obtained using FFA correlated with, and were confirmed by conventional lesion area measurements from isolectin stained choroidal flatmounts, where lesions of anti-VEGF treated rats were significantly smaller at 2 weeks (p = 0.049) and 3 weeks (p<0.001) post laser. Conclusion The presented method of in-vivo FFA quantification of CNV, including acquisition variable corrections, using the Micron III system and common use software establishes a reliable method for detecting and quantifying CNV enabling longitudinal studies and represents an important alternative to conventional CNV quantification methods.
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Affiliation(s)
- Jonathan P. Wigg
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Hong Zhang
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Eye Hospital, Harbin Medical University, Nangang District, Harbin, Heilongjiang Province, China
- * E-mail:
| | - Dong Yang
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
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Reichhart N, Keckeis S, Fried F, Fels G, Strauss O. Regulation of surface expression of TRPV2 channels in the retinal pigment epithelium. Graefes Arch Clin Exp Ophthalmol 2015; 253:865-74. [DOI: 10.1007/s00417-014-2917-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/23/2014] [Accepted: 12/23/2014] [Indexed: 12/31/2022] Open
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Li X, Zhao H, Wang Q, Liang H, Jiang X. Fucoidan protects ARPE-19 cells from oxidative stress via normalization of reactive oxygen species generation through the Ca²⁺-dependent ERK signaling pathway. Mol Med Rep 2015; 11:3746-52. [PMID: 25606812 DOI: 10.3892/mmr.2015.3224] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 12/12/2014] [Indexed: 11/06/2022] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes mellitus (DM) and it is the main cause of loss of vision. In previous years, interest in the biological activities of marine organisms has intensified. The effect of fucoidan from the seaweed Fucus vesiculosus on the molecular mechanisms of numerous diseases has been studied, while to date, its effect on DR was yet to be investigated. Therefore, the aim of the present study was to evaluate the role of fucoidan in DR. The human retinal pigment epithelial cell line ARPE‑19 was exposed to high D‑glucose in the presence or absence of fucoidan. Cell viability was monitored using MTT and lactate dehydrogenase assays. The intracellular reactive oxygen species (ROS) generation was measured using fluorescence spectrophotometry. Cell apoptosis was measured by flow cytometry using Annexin V‑fluorescein isothiocyanate staining. Ca2+ influx was measured with a calcium imaging system and the activation of the extracellular signal‑regulated kinase (ERK) protein was evaluated using western blot analysis. The non‑toxic fucoidan protected ARPE‑19 cells from high glucose‑induced cell death and normalized high glucose‑induced generation of ROS. Fucoidan also inhibited high glucose‑induced cell apoptosis, as well as the Ca2+ influx and ERK1/2 phosphorylation in ARPE‑19 cells. Taken together, these findings indicated that fucoidan protects ARPE‑19 cells against high glucose‑induced oxidative damage via normalization of ROS generation through the Ca2+‑dependent ERK signaling pathway.
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Affiliation(s)
- Xiaoxia Li
- Department of Clinical Biochemistry Laboratory, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Haiyan Zhao
- Department of Ophthalmology, Central Hospital of Liaoyang City, Liaoyang, Liaoning 111000, P.R. China
| | - Qingfa Wang
- Department of Emergency, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Hongyan Liang
- Department of Clinical Biochemistry Laboratory, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Xiaofeng Jiang
- Department of Clinical Biochemistry Laboratory, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
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Ko JA, Hirata J, Yamane K, Sonoda KH, Kiuchi Y. Up-regulation of semaphorin 4A expression in human retinal pigment epithelial cells by PACAP released from cocultured neural cells. Cell Biochem Funct 2014; 33:29-36. [PMID: 25515530 DOI: 10.1002/cbf.3082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/04/2014] [Accepted: 11/05/2014] [Indexed: 01/01/2023]
Abstract
Development and homeostasis of multicellular organisms require interactions between neighbouring cells. We recently established an in vitro model of cell-cell interaction based on a collagen vitrigel membrane. We have now examined the role of neural cells in retinal homeostasis by coculture of human retinal pigment epithelial (RPE) cells and neural cells on opposite sides of such a membrane. The neural cells (differentiated PC12 cells) induced up-regulation of semaphorin 4A (Sema4A), a member of the semaphorin family of neural guidance proteins, in RPE (ARPE19) cells. This effect of the neural cells was mimicked by the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) and was abolished by the PACAP antagonist PACAP(6-38). Coculture with neural cells or stimulation with PACAP also induced the phosphorylation of extracellular-signal-regulated kinase in ARPE19 cells, and this effect of the neural cells was inhibited by PACAP(6-38). Finally, among various cytokines examined, only the amount of interleukin-6 released by cocultures of ARPE19 and neural cells differed from that released by ARPE19 cells cultured alone. Interleukin-6 was not detected in culture supernatants of neural cells, and the reduction in the amount of interleukin-6 released by the cocultures compared with that released by ARPE19 cells alone was prevented by PACAP(6-38). Our findings suggest that PACAP released from retinal neural cells (photoreceptors or optic nerve cells) may regulate Sema4A expression in RPE cells and thereby contribute to the maintenance of retinal structure and function. Development and homeostasis of multicellular organisms require interactions between neighbouring cells. With the use of a coculture system based on a collagen vitrigel membrane, we have now shown that neural cells induce up-regulation of the neural guidance protein Sema4A in RPE cells. This effect of neural cells appears to be mediated by the neuropeptide PACAP. PACAP released from retinal neural cells (photoreceptors or optic nerve cells) may thus regulate Sema4A expression in RPE cells and thereby contribute to the maintenance of retinal structure and function.
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Affiliation(s)
- Ji-Ae Ko
- Department of Ophthalmology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima City, Hiroshima, Japan
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Scotopic microperimetry in the early diagnosis of age-related macular degeneration: preliminary study. BIOMED RESEARCH INTERNATIONAL 2014; 2014:671529. [PMID: 25548774 PMCID: PMC4274674 DOI: 10.1155/2014/671529] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 09/14/2014] [Accepted: 09/17/2014] [Indexed: 11/18/2022]
Abstract
Background. Recent clinical studies have shown that, in some degenerative retinal diseases, like age-related macular degeneration (AMD), the sensitivity of the rods decreases more rapidly than the sensitivity of the cones. The aim of this study was to evaluate if there is a correlation between the presence of hard drusen at the macular level and the rod damage responsible for the reduction in scotopic retinal sensitivity in subjects at risk for AMD. Methods. The authors selected 24 subjects (14 men and 10 women) with an average age of 67.25 ± 5.7 years. Macular hard drusen were present in 50% of the subjects at the fundus oculi exam. The researchers evaluated the retinal sensitivity to light in mesopic and scotopic conditions of each subject with an MP-1 scotopic microperimeter (MP-1S). Results. In subjects with hard drusen in the fundus oculi examination, there was a statistically significant reduction in scotopic retinal sensitivity, while the mesopic retinal sensitivity was not compromised. Conclusion. This study revealed how the presence of hard drusen at the macular level is associated with a reduction in scotopic retinal sensitivity compared to a control group of healthy subjects. Retinal functionality in a scotopic setting examined with MP-1S could be useful in early diagnosis of AMD.
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Squamosamide derivative FLZ protects retinal pigment epithelium cells from oxidative stress through activation of epidermal growth factor receptor (EGFR)-AKT signaling. Int J Mol Sci 2014; 15:18762-75. [PMID: 25329617 PMCID: PMC4227245 DOI: 10.3390/ijms151018762] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/02/2014] [Accepted: 09/11/2014] [Indexed: 12/19/2022] Open
Abstract
Reactive oxygen species (ROS)-mediated retinal pigment epithelium (RPE) cell apoptosis is attributed to age-related macular degeneration (AMD) pathogenesis. FLZ, a novel synthetic squamosamide derivative from a Chinese herb, Annona glabra, has displayed significant cyto-protective activity. In the current study, we explored the pro-survival effect of FLZ in oxidative stressed-RPE cells and studied the underlying signaling mechanisms. Our results showed that FLZ attenuated hydrogen peroxide (H2O2)-induced viability decrease and apoptosis in the RPE cell line (ARPE-19 cells) and in primary mouse RPE cells. Western blotting results showed that FLZ activated AKT signaling in RPE cells. The AKT-specific inhibitor, MK-2206, the phosphoinositide 3-kinase (PI3K)/AKT pan inhibitor, wortmannin, and AKT1-shRNA (short hairpin RNA) depletion almost abolished FLZ-mediated pro-survival/anti-apoptosis activity. We discovered that epidermal growth factor receptor (EGFR) trans-activation mediated FLZ-induced AKT activation and the pro-survival effect in RPE cells, and the anti-apoptosis effect of FLZ against H2O2 was inhibited by the EGFR inhibitor, PD153035, or by EGFR shRNA-knockdown. In conclusion, FLZ protects RPE cells from oxidative stress through activation of EGFR-AKT signaling, and our results suggest that FLZ might have therapeutic values for AMD.
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Koinzer S, Reinecke K, Herdegen T, Roider J, Klettner A. Oxidative Stress Induces Biphasic ERK1/2 Activation in the RPE with Distinct Effects on Cell Survival at Early and Late Activation. Curr Eye Res 2014; 40:853-7. [PMID: 25251900 DOI: 10.3109/02713683.2014.961613] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE Oxidative stress is considered a major factor in the deterioration of retinal pigment epithelium (RPE) cells in dry age-related macular degeneration (AMD). The MAPK ERK1/2 can be activated by oxidative stress, may exert both pro- and anti-apoptotic functions, and has recently been proposed as a major factor in RPE degeneration in atrophic changes. Nrf2 is a master regulator of oxidative stress defense and ERK1/2 is an upstream activator of Nrf2. In this study, we investigate the participation of ERK1/2 in oxidative stress pathways in connection with Nrf2. METHODS Nrf2 knock-out and wild-type primary RPE cells were prepared from mouse eyes. Oxidative stress was induced by different concentrations of t-butylhydroperoxide. Mitogen-activated protein kinases (MAPKs) were blocked by commercially available inhibitors (SB203580, U0126, SP600125). Cell viability was determined by MTT assay. ERK1/2 expression and activation were assessed by Western blotting. RESULTS Oxidative stress induced concentration dependent cell death, which occurred at lower concentrations in Nrf2 knock-out RPE. Western blot analysis displayed a biphasic activation of ERK1/2 in murine wild-type RPE and the inhibition of late, but not early activation of ERK1/2 exerted protection in wild-type murine RPE cells. The biphasic activation of ERK1/2 is lost in Nrf2 knock-out mice, and inhibition of ERK1/2 was generally protective. The inhibition of MAPK JNK or p38 exerted no protection, irrespective of Nrf2. CONCLUSION RPE cells display a biphasic activation of ERK1/2 after oxidative insult, of which the late activation is pro-apoptotic. The biphasic activation is lost in Nrf2 knock-outs, suggesting that early ERK1/2 activation may be connected to Nrf2 signaling. In addition, ERK1/2 activation in Nrf2 knock-outs mediates oxidative stress-induced cell death.
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Retinal pigment epithelial cells undergoing mitotic catastrophe are vulnerable to autophagy inhibition. Cell Death Dis 2014; 5:e1303. [PMID: 24967965 PMCID: PMC4611738 DOI: 10.1038/cddis.2014.266] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/20/2014] [Accepted: 05/20/2014] [Indexed: 12/03/2022]
Abstract
The increased mitochondrial DNA damage leads to altered functional capacities of retinal pigment epithelial (RPE) cells. A previous study showed the increased autophagy in RPE cells caused by low concentrations of rotenone, a selective inhibitor of mitochondrial complex I. However, the mechanism by which autophagy regulates RPE cell death is still unclear. In the present study, we examined the mechanism underlying the regulation of RPE cell death through the inhibition of mitochondrial complex I. We report herein that rotenone induced mitotic catastrophe (MC) in RPE cells. We further observed an increased level of autophagy in the RPE cells undergoing MC (RPE-MC cells). Importantly, autophagy inhibition induced nonapoptotic cell death in RPE-MC cells. These findings indicate that autophagy has a pivotal role in the survival of RPE-MC cells. We next observed PINK1 accumulation in the mitochondrial membrane and parkin translocation into the mitochondria from the cytosol in the rotenone-treated RPE-MC cells, which indicates that increased mitophagy accompanies MC in ARPE-19 cells. Noticeably, the mitophagy also contributed to the cytoprotection of RPE-MC cells. Although there might be a significant gap in the roles of autophagy and mitophagy in the RPE cells in vivo, our in vitro study suggests that autophagy and mitophagy presumably prevent the RPE-MC cells from plunging into cell death, resulting in the prevention of RPE cell loss.
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30
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Rabin DM, Rabin RL, Blenkinsop TA, Temple S, Stern JH. Chronic oxidative stress upregulates Drusen-related protein expression in adult human RPE stem cell-derived RPE cells: a novel culture model for dry AMD. Aging (Albany NY) 2013; 5:51-66. [PMID: 23257616 PMCID: PMC3616231 DOI: 10.18632/aging.100516] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The goal of this study was to examine changes in the expression of transcripts and proteins associated with drusen in Age-related Macular Degeneration (AMD) after exposing human retinal pigment epithelium (hRPE) cells to chronic oxidative stress. METHODS Primary adult human RPE cells were isolated from cadaveric donor eyes. The subpopulation of RPE stem cells (RPESCs) was activated, expanded, and then differentiated into RPE progeny. Confluent cultures of RPESC-derived hRPE and ARPE-19 cells were exposed to a regimen of tert-butylhydroperoxide (TBHP) for 1-5 days. After treatment, gene expression was measured by quantitative PCR (qPCR), protein expression was assessed by immunocytochemistry and transepithelial resistance and cell toxicity were measured. RESULTS hRPE cells exposed to a regimen of TBHP for 5 days upregulate expression of several molecules identified in drusen, including molecular chaperones and pro-angiogenic factors. 5-day TBHP treatment was significantly more effective than 1-day treatment at eliciting these effects. The extent of hRPE response to 5-day treatment varied significantly between individual donors, nevertheless, 6 transcripts were reliably significantly upregulated. ARPE-19 cells treated with the same 5-day stress regime did not show the same pattern of response and did not upregulate this group of transcripts. CONCLUSIONS RPESC-derived hRPE cells change significantly when exposed to repeated oxidative stress conditions, upregulating expression of several drusen-related proteins and transcripts. This is consistent with the hypothesis that hRPE cells are competent to be a source of proteins found in drusen deposits. Our results suggest that donor-specific genetic and environmental factors influence the RPE stress response. ARPE-19 cells appear to be less representative of AMD-like changes than RPESC-derived hRPE. This adult stem cell-based system using chronic TBHP treatment of hRPE represents a novel in vitro model useful for the study of drusen formation and dry AMD pathophysiology.
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Affiliation(s)
- David M Rabin
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany NY 12208, USA
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31
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Age-related macular degeneration (AMD): Current concepts in pathogenesis and prospects for treatment. Tissue Eng Regen Med 2013. [DOI: 10.1007/s13770-012-0374-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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32
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Diminishing risk for age-related macular degeneration with nutrition: a current view. Nutrients 2013; 5:2405-56. [PMID: 23820727 PMCID: PMC3738980 DOI: 10.3390/nu5072405] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 06/24/2013] [Accepted: 06/24/2013] [Indexed: 02/02/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. Clinical hallmarks of AMD are observed in one third of the elderly in industrialized countries. Preventative interventions through dietary modification are attractive strategies, because they are more affordable than clinical therapies, do not require specialists for administration and many studies suggest a benefit of micro- and macro-nutrients with respect to AMD with few, if any, adverse effects. The goal of this review is to provide information from recent literature on the value of various nutrients, particularly omega-3 fatty acids, lower glycemic index diets and, perhaps, some carotenoids, with regard to diminishing risk for onset or progression of AMD. Results from the upcoming Age-Related Eye Disease Study (AREDS) II intervention trial should be particularly informative.
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33
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Age-Related Macular Degeneration. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00065-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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34
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Gullapalli VK, Khodair MA, Wang H, Sugino IK, Madreperla S, Zarbin MA. Transplantation Frontiers. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00125-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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35
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The Influence of NaIO3-Induced Retinal Degeneration on Intra-retinal Layer and the Changes of Expression Profile/Morphology of DA-ACs and mRGCS. Mol Neurobiol 2012; 47:241-60. [DOI: 10.1007/s12035-012-8366-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 10/22/2012] [Indexed: 10/27/2022]
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36
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Liu T, Hui L, Wang YS, Guo JQ, Li R, Su JB, Chen JK, Xin XM, Li WH. In-vivo investigation of laser-induced choroidal neovascularization in rat using spectral-domain optical coherence tomography (SD-OCT). Graefes Arch Clin Exp Ophthalmol 2012; 251:1293-301. [PMID: 23114625 DOI: 10.1007/s00417-012-2185-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 09/06/2012] [Accepted: 10/15/2012] [Indexed: 12/26/2022] Open
Abstract
PURPOSE This study investigated the in-vivo formation process of laser-induced choroidal neovascularization (CNV) in rat using high-resolution spectral-domain optical coherence tomography (SD-OCT), and compared the results to histological methods. METHODS Brown Norway rats (n = 60, 6-8 weeks of age) received 532-nm diode laser photocoagulation. SD-OCT and fluorescein angiography (FA) were performed in vivo 2, 5, 7, 14, and 21 days post-laser application. Haematoxylin and eosin (H&E) staining and immunohistochemistry for CD31, phosphorylated vascular endothelial factor receptor 2 (pVEGFR2) were conducted at each time point to observe the CNV in vitro. Choroidal flatmount preparations were observed using a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM). RESULTS SD-OCT monitored the longitudinal morphological changes of laser-induced CNV. CNV reached its maximal size on day 7, and began a gradual reduction on day 14. FA revealed similar dynamic changes in leakage. CNV thickness, as assessed by SD-OCT, was consistent with H&E-stained sections at each time point. CLSM and SEM revealed the details of the fibrovascular membrane. CD31 and pVEGFR2 expression supported the results of SD-OCT and histology. CONCLUSIONS SD-OCT was a convenient and reliable tool for the imaging of the CNV formation process and quantification of the lesion size in vivo.
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Affiliation(s)
- Tao Liu
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
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37
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Pilot study for the detection of early exudative age-related macular degeneration with optical coherence tomography. Retina 2012; 32:1045-56. [PMID: 22186740 DOI: 10.1097/iae.0b03e31823fb82b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Optical coherence tomography (OCT) provides microscopic retinal images. Optical coherence tomography is noninvasive, using light waves to produce detailed retinal images. Here, we investigate the ability of OCT to detect early choroidal neovascularization in age-related macular degeneration. METHODS Seventy-nine patients, diagnosed with nonexudative macular degeneration in one eye and exudative macular degeneration in the other were enrolled in this prospective, observational, nonrandomized study. Participants underwent examination (visual acuity, intraocular pressure, biomicroscopy, and ophthalmoscopy) followed by OCT in the study eye (nonexudative macular degeneration eye) every 3 months for 2 years. If examination did not show choroidal neovascularization, but OCT images raised suspicion, patients were reexamined in 4 weeks to 6 weeks and/or fluorescein angiography was performed. Visual acuity, OCT anomaly detected, and time between OCT and fluorescein angiography detection were examined. RESULTS Fifteen (19%) patients developed exudative macular degeneration, as confirmed by fluorescein angiography, in the study eye. Four additional patients showed potential exudative macular degeneration on OCT only. Of the 15 patients who developed exudative macular degeneration, 13 had disease progression identified on OCT before examination and/or fluorescein angiography showed changes. Subretinal pigment epithelium fluid was the most common OCT anomaly, with development of sub-/intraretinal fluid also visible. CONCLUSION Optical coherence tomography could be a powerful screening tool for patients with age-related macular degeneration at high risk for developing choroidal neovascularization.
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38
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Ultrastructure of the human retina in aging and various pathological states. Micron 2012; 43:759-81. [DOI: 10.1016/j.micron.2012.01.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 01/24/2012] [Indexed: 11/22/2022]
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39
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Goldenberg D, Moisseiev E, Goldstein M, Loewenstein A, Barak A. Enhanced Depth Imaging Optical Coherence Tomography: Choroidal Thickness and Correlations With Age, Refractive Error, and Axial Length. Ophthalmic Surg Lasers Imaging Retina 2012; 43:296-301. [DOI: 10.3928/15428877-20120426-02] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 02/17/2012] [Indexed: 02/01/2023]
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40
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Chucair-Elliott AJ, Elliott MH, Wang J, Moiseyev GP, Ma JX, Politi LE, Rotstein NP, Akira S, Uematsu S, Ash JD. Leukemia inhibitory factor coordinates the down-regulation of the visual cycle in the retina and retinal-pigmented epithelium. J Biol Chem 2012; 287:24092-102. [PMID: 22645143 DOI: 10.1074/jbc.m112.378240] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leukemia inhibitory factor (LIF), an interleukin-6 family neurocytokine, is up-regulated in response to different types of retinal stress and has neuroprotective activity through activation of the gp130 receptor/STAT3 pathway. We observed that LIF induces rapid, robust, and sustained activation of STAT3 in both the retina and retinal pigmented epithelium (RPE). Here, we tested whether LIF-induced STAT3 activation within the RPE can down-regulate RPE65, the central enzyme in the visual cycle that provides the 11-cis-retinal chromophore to photoreceptors in vivo. We generated conditional knock-out mice to specifically delete STAT3 or gp130 in RPE, retina, or both RPE and retina. After intravitreal injection of LIF, we analyzed the expression levels of visual cycle genes and proteins, isomerase activity of RPE65, levels of rhodopsin protein, and the rates of dark adaptation and rhodopsin regeneration. We found that RPE65 protein levels and isomerase activity were reduced and recovery of bleachable rhodopsin was delayed in LIF-injected eyes. In mice with functional gp130/STAT3 signaling in the retina, rhodopsin protein was also reduced by LIF. However, the LIF-induced down-regulation of RPE65 required a functional gp130/STAT3 cascade intrinsic to RPE. Our data demonstrate that a single cytokine, LIF, can simultaneously and independently affect both RPE and photoreceptors through the same signaling cascade to reduce the generation and utilization of 11-cis-retinal.
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Affiliation(s)
- Ana J Chucair-Elliott
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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41
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Mettu PS, Wielgus AR, Ong SS, Cousins SW. Retinal pigment epithelium response to oxidant injury in the pathogenesis of early age-related macular degeneration. Mol Aspects Med 2012; 33:376-98. [PMID: 22575354 DOI: 10.1016/j.mam.2012.04.006] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 04/14/2012] [Indexed: 01/06/2023]
Abstract
Age-related macular degeneration (AMD) represents the leading cause of vision loss in the elderly. Accumulation of lipid- and protein-rich deposits under the retinal pigment epithelium (RPE) heralds the onset of early AMD, but the pathogenesis of subretinal deposit formation is poorly understood. Numerous hypothetical models of deposit formation have been proposed, including hypotheses for a genetic basis, choroidal hypoperfusion, abnormal barrier formation, and lysosomal failure. This review explore the RPE injury hypothesis, characterized by three distinct stages (1) Initial RPE oxidant injury, caused by any number of endogenous or exogenous oxidants, results in extrusion of cell membrane "blebs," together with decreased activity of matrix metalloproteinases (MMPs), promoting bleb accumulation under the RPE as basal laminar deposits (BLD). (2) RPE cells are subsequently stimulated to increase synthesis of MMPs and other molecules responsible for extracellular matrix turnover (i.e., producing decreased collagen), affecting both RPE basement membrane and Bruchs membrane (BrM). This process leads to progression of BLD into basal linear deposits (BLinD) and drusen by admixture of blebs into BrM, followed by the formation of new basement membrane under the RPE to trap these deposits within BrM. We postulate that various hormones and other plasma-derived molecules related to systemic health cofactors are implicated in this second stage. (3) Finally, macrophages are recruited to sites of RPE injury and deposit formation. The recruitment of nonactivated or scavenging macrophages may remove deposits without further injury, while the recruitment of activated or reparative macrophages, through the release of inflammatory mediators, growth factors, or other substances, may promote complications and progression to the late forms of the disease.
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Affiliation(s)
- Priyatham S Mettu
- Duke Center for Macular Diseases, Duke Eye Center, Durham, NC 27710, USA
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42
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Weikel KA, Chiu CJ, Taylor A. Nutritional modulation of age-related macular degeneration. Mol Aspects Med 2012; 33:318-75. [PMID: 22503690 DOI: 10.1016/j.mam.2012.03.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 03/30/2012] [Indexed: 11/24/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30-50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated with AMD are in excess of $340 billion US (American-Health-Assistance-Foundation, 2012). The majority of AMD patients in the United States are not eligible for clinical treatments (Biarnes et al., 2011; Klein et al., 2011). Preventive interventions through dietary modulation are attractive strategies because many studies suggest a benefit of micro- and macronutrients with respect to AMD, as well as other age-related debilities, and with few, if any, adverse effects (Chiu, 2011). Preservation of vision would enhance quality of life for millions of elderly people, and alleviate the personal and public health financial burden of AMD (Frick et al., 2007; Wood et al., 2011). Observational studies indicate that maintaining adequate levels of omega-3 fatty acids (i.e. with 2 servings/week of fish) or a low glycemic index diet may be particularly beneficial for early AMD and that higher levels of carotenoids may be protective, most probably, against neovascular AMD. Intervention trials are needed to better understand the full effect of these nutrients and/or combinations of nutrients on retinal health. Analyses that describe effects of a nutrient on onset and/or progress of AMD are valuable because they indicate the value of a nutrient to arrest AMD at the early stages. This comprehensive summary provides essential information about the value of nutrients with regard to diminishing risk for onset or progress of AMD and can serve as a guide until data from ongoing intervention trials are available.
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Affiliation(s)
- Karen A Weikel
- Laboratory for Nutrition and Vision Research, JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
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Nag TC, Wadhwa S. WITHDRAWN: Ultrastructure of the human retina in aging and various pathological states. Micron 2011:S0968-4328(11)00226-5. [PMID: 22410275 DOI: 10.1016/j.micron.2011.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 12/07/2011] [Indexed: 10/14/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Tapas Chandra Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
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Nicotine reduces VEGF-secretion and phagocytotic activity in porcine RPE. Graefes Arch Clin Exp Ophthalmol 2011; 250:33-8. [DOI: 10.1007/s00417-011-1776-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 07/04/2011] [Accepted: 07/28/2011] [Indexed: 10/17/2022] Open
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El-Mollayess GM, Noureddine BN, Bashshur ZF. Bevacizumab and Neovascular Age Related Macular Degeneration: Pathogenesis and Treatment. Semin Ophthalmol 2011; 26:69-76. [DOI: 10.3109/08820538.2010.545100] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Schimel AM, Abraham L, Cox D, Sene A, Kraus C, Dace DS, Ercal N, Apte RS. N-acetylcysteine amide (NACA) prevents retinal degeneration by up-regulating reduced glutathione production and reversing lipid peroxidation. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:2032-43. [PMID: 21457933 DOI: 10.1016/j.ajpath.2011.01.036] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 01/18/2011] [Accepted: 01/25/2011] [Indexed: 02/07/2023]
Abstract
Oxidative stress plays a critical role in accelerating retinal pigment epithelial dysfunction and death in degenerative retinal diseases, including age-related macular degeneration. Given the key role of oxidative stress-induced retinal pigment epithelial cell death and secondary photoreceptor loss in the pathogenesis of age-related macular degeneration, we hypothesized that a novel thiol antioxidant, N-acetylcysteine amide (NACA), might ameliorate cellular damage and subsequent loss of vision. Treatment of human retinal pigment epithelial cells with NACA protected against oxidative stress-induced cellular injury and death. NACA acted mechanistically by scavenging existing reactive oxygen species while halting production of reactive oxygen species by reversing lipid peroxidation. Furthermore, NACA functioned by increasing the levels of reduced glutathione and the phase II detoxification enzyme glutathione peroxidase. Treatment of mice exposed to phototoxic doses of light with NACA maintained retinal pigment epithelial cell integrity and prevented outer nuclear layer cell death as examined by histopathologic methods and rescued photoreceptor function as measured by electroretinography. These observations indicate that NACA protects against oxidative stress-induced retinal pigment epithelial and photoreceptor cell death in vitro and in vivo. The data suggest that NACA may be a novel treatment in rescuing retinal function and preventing vision loss secondary to retinal degenerative diseases, including age-related macular degeneration.
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Affiliation(s)
- Andrew M Schimel
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, USA
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Evidence of alpha 7 nicotinic acetylcholine receptor expression in retinal pigment epithelial cells. Vis Neurosci 2010; 27:139-47. [DOI: 10.1017/s0952523810000246] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractSome evidence suggests that retinal pigment epithelium (RPE) can express nicotinic acetylcholine receptors (nAChRs) as described for other epithelial cells, where nAChRs have been involved in processes such as cell development, cell death, cell migration, and angiogenesis. This study is designed to determine the expression and activity of α7 nAChRs in RPE cells. Reverse transcriptase (RT)-PCR was performed to test the expression of nicotinic α7 subunit in bovine RPE cells. Protein expression was determined by Western blot and by immunocytochemistry. Expression of nicotinic α7 subunits was also analyzed in cryostat sections of albino rat retina. Changes in protein expression were tested under hypoxic conditions. Functional nAChRs were studied by examining the Ca2+transients elicited by nicotine and acetylcholine stimulation in fura-2–loaded cells. Expression of endogenous modulators of nAChRs was analyzed by RT-PCR and Western blot in retina and RPE. Cultured bovine RPE cells expressed nicotinic receptors containing α7 subunit. RT-PCR amplified the expected specific α7 fragment. Western blotting showed expression at the protein level, with a specific band being found at 57 kDa in both cultured and freshly isolated RPE cells. Expression of nAChRs was confirmed for cultured cells by immunofluorescence. Immunohistochemistry confirmed α7 receptor expression in rat RPE retina. α7 receptor expression was down-regulated by long-term hypoxia. A small subpopulation of RPE cultured cells showed functional nAChRs, as evidenced by the selective response elicited by nicotine and acetylcholine stimulation. Expression of the endogenous nicotinic receptors’ modulator lynx1 was confirmed in bovine retina and RPE, and expression of lynx1 and other endogenous nicotinic receptor modulators (SLURP1 and RGD1308195) were also confirmed in rat retina. These results suggest that nAChRs could have a significant role in RPE, which may not be related to the traditional role in nerve transmission but could more likely be related to the nonneuronal cholinergic system in the eye.
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Schmidt-Erfurth U. Clinical safety of ranibizumab in age-related macular degeneration. Expert Opin Drug Saf 2010; 9:149-65. [PMID: 20001757 DOI: 10.1517/14740330903418422] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Clinical safety of pharmaceutical products in the elderly is vital because of their increased risk of cardiac and other adverse events. AREAS COVERED IN THIS REVIEW Search of the Medline database, including articles and abstracts from 1984 to 2009. WHAT THE READER WILL GAIN Knowledge of ocular and systemic risks: The rate of endophthalmitis was 0.05% per injection (MARINA) and <0.1% per injection (ANCHOR), rates confirmed in a retrospective analysis of 14,320 injections. Moderate increases in intraocular pressure were transient, and incidences of intraocular inflammation were rarely serious. Systemic arterial thromboembolic events occurred in 4.6 and 0% of ranibizumab-treated patients and in 3.8 and 0% of sham-treated patients in MARINA (2 years) and PIER (1 year), respectively. In SAILOR, there was a numerically higher rate of cerebrovascular stroke with 0.5 mg ranibizumab compared with 0.3 mg ranibizumab (1.2 vs 0.7%), which was a non-statistically significant trend in patients with a history of stroke. TAKE HOME MESSAGE Although further studies to investigate the risk of stroke with ranibizumab therapy are required, repeated intravitreal ranibizumab was well tolerated and not associated with clinically significant safety risks during up to 2 years of treatment.
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Affiliation(s)
- Ursula Schmidt-Erfurth
- Medical University of Vienna, Department of Ophthalmology, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
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Abstract
The choroid of the eye is primarily a vascular structure supplying the outer retina. It has several unusual features: It contains large membrane-lined lacunae, which, at least in birds, function as part of the lymphatic drainage of the eye and which can change their volume dramatically, thereby changing the thickness of the choroid as much as four-fold over a few days (much less in primates). It contains non-vascular smooth muscle cells, especially behind the fovea, the contraction of which may thin the choroid, thereby opposing the thickening caused by expansion of the lacunae. It has intrinsic choroidal neurons, also mostly behind the central retina, which may control these muscles and may modulate choroidal blood flow as well. These neurons receive sympathetic, parasympathetic and nitrergic innervation. The choroid has several functions: Its vasculature is the major supply for the outer retina; impairment of the flow of oxygen from choroid to retina may cause Age-Related Macular Degeneration. The choroidal blood flow, which is as great as in any other organ, may also cool and warm the retina. In addition to its vascular functions, the choroid contains secretory cells, probably involved in modulation of vascularization and in growth of the sclera. Finally, the dramatic changes in choroidal thickness move the retina forward and back, bringing the photoreceptors into the plane of focus, a function demonstrated by the thinning of the choroid that occurs when the focal plane is moved back by the wearing of negative lenses, and, conversely, by the thickening that occurs when positive lenses are worn. In addition to focusing the eye, more slowly than accommodation and more quickly than emmetropization, we argue that the choroidal thickness changes also are correlated with changes in the growth of the sclera, and hence of the eye. Because transient increases in choroidal thickness are followed by a prolonged decrease in synthesis of extracellular matrix molecules and a slowing of ocular elongation, and attempts to decouple the choroidal and scleral changes have largely failed, it seems that the thickening of the choroid may be mechanistically linked to the scleral synthesis of macromolecules, and thus may play an important role in the homeostatic control of eye growth, and, consequently, in the etiology of myopia and hyperopia.
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Affiliation(s)
- Debora L Nickla
- Department of Biosciences, New England College of Optometry, Boston, MA 02115, USA.
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