251
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Human stem cell-derived retinal epithelial cells activate complement via collectin 11 in response to stress. Sci Rep 2017; 7:14625. [PMID: 29116192 PMCID: PMC5677091 DOI: 10.1038/s41598-017-15212-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 10/24/2017] [Indexed: 01/07/2023] Open
Abstract
Age-related macular degeneration (AMD) is a major cause of blindness and is associated with complement dysregulation. The disease is a potential target for stem cell therapy but success is likely to be limited by the inflammatory response. We investigated the innate immune properties of human induced-pluripotent stem cell (iPSC)-derived RPE cells, particularly with regard to the complement pathway. We focused on collectin-11 (CL-11), a pattern recognition molecule that can trigger complement activation in renal epithelial tissue. We found evidence of constitutive and hypoxia-induced expression of CL-11 in iPS-RPE cells, and in the extracellular fluid. Complement activation on the cell surface occurred in conjunction with CL-11 binding. CL-11 has been shown to activate inflammatory responses through recognition of L-fucose, which we confirmed by showing that fucosidase-treated cells, largely, failed to activate complement. The presence of CL-11 in healthy murine and human retinal tissues confirmed the biological relevance of CL-11. Our data describe a new trigger mechanism of complement activation that could be important in disease pathogenesis and therapeutic interventions.
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252
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On phagocytes and macular degeneration. Prog Retin Eye Res 2017; 61:98-128. [DOI: 10.1016/j.preteyeres.2017.06.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/29/2017] [Accepted: 06/05/2017] [Indexed: 12/17/2022]
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253
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Hallam D, Collin J, Bojic S, Chichagova V, Buskin A, Xu Y, Lafage L, Otten EG, Anyfantis G, Mellough C, Przyborski S, Alharthi S, Korolchuk V, Lotery A, Saretzki G, McKibbin M, Armstrong L, Steel D, Kavanagh D, Lako M. An Induced Pluripotent Stem Cell Patient Specific Model of Complement Factor H (Y402H) Polymorphism Displays Characteristic Features of Age-Related Macular Degeneration and Indicates a Beneficial Role for UV Light Exposure. Stem Cells 2017; 35:2305-2320. [PMID: 28913923 PMCID: PMC5698780 DOI: 10.1002/stem.2708] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/21/2017] [Accepted: 09/07/2017] [Indexed: 11/11/2022]
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness, accounting for 8.7% of all blindness globally. Vision loss is caused ultimately by apoptosis of the retinal pigment epithelium (RPE) and overlying photoreceptors. Treatments are evolving for the wet form of the disease; however, these do not exist for the dry form. Complement factor H polymorphism in exon 9 (Y402H) has shown a strong association with susceptibility to AMD resulting in complement activation, recruitment of phagocytes, RPE damage, and visual decline. We have derived and characterized induced pluripotent stem cell (iPSC) lines from two subjects without AMD and low-risk genotype and two patients with advanced AMD and high-risk genotype and generated RPE cells that show local secretion of several proteins involved in the complement pathway including factor H, factor I, and factor H-like protein 1. The iPSC RPE cells derived from high-risk patients mimic several key features of AMD including increased inflammation and cellular stress, accumulation of lipid droplets, impaired autophagy, and deposition of "drüsen"-like deposits. The low- and high-risk RPE cells respond differently to intermittent exposure to UV light, which leads to an improvement in cellular and functional phenotype only in the high-risk AMD-RPE cells. Taken together, our data indicate that the patient specific iPSC model provides a robust platform for understanding the role of complement activation in AMD, evaluating new therapies based on complement modulation and drug testing. Stem Cells 2017;35:2305-2320.
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Affiliation(s)
- Dean Hallam
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Joseph Collin
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Sanja Bojic
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Valeria Chichagova
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Adriana Buskin
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Yaobo Xu
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Lucia Lafage
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Elsje G Otten
- Campus for Ageing and Vitality, Institute for Cell and Molecular Biosciences and Institute for Ageing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - George Anyfantis
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Carla Mellough
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Stefan Przyborski
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Sameer Alharthi
- Princess Al Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Saudi Arabia
| | - Viktor Korolchuk
- Campus for Ageing and Vitality, Institute for Cell and Molecular Biosciences and Institute for Ageing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Gabriele Saretzki
- Campus for Ageing and Vitality, Institute for Cell and Molecular Biosciences and Institute for Ageing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Lyle Armstrong
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - David Steel
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - David Kavanagh
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Majlinda Lako
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
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254
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Hazim RA, Karumbayaram S, Jiang M, Dimashkie A, Lopes VS, Li D, Burgess BL, Vijayaraj P, Alva-Ornelas JA, Zack JA, Kohn DB, Gomperts BN, Pyle AD, Lowry WE, Williams DS. Differentiation of RPE cells from integration-free iPS cells and their cell biological characterization. Stem Cell Res Ther 2017; 8:217. [PMID: 28969679 PMCID: PMC5625837 DOI: 10.1186/s13287-017-0652-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 08/16/2017] [Accepted: 08/29/2017] [Indexed: 01/18/2023] Open
Abstract
Background Dysfunction of the retinal pigment epithelium (RPE) is implicated in numerous forms of retinal degeneration. The readily accessible environment of the eye makes it particularly suitable for the transplantation of RPE cells, which can now be derived from autologous induced pluripotent stem cells (iPSCs), to treat retinal degeneration. For RPE transplantation to become feasible in the clinic, patient-specific somatic cells should be reprogrammed to iPSCs without the introduction of reprogramming genes into the genome of the host cell, and then subsequently differentiated into RPE cells that are well characterized for safety and functionality prior to transplantation. Methods We have reprogrammed human dermal fibroblasts to iPSCs using nonintegrating RNA, and differentiated the iPSCs toward an RPE fate (iPSC-RPE), under Good Manufacturing Practice (GMP)-compatible conditions. Results Using highly sensitive assays for cell polarity, structure, organelle trafficking, and function, we found that iPSC-RPE cells in culture exhibited key characteristics of native RPE. Importantly, we demonstrate for the first time with any stem cell-derived RPE cell that live cells are able to support dynamic organelle transport. This highly sensitive test is critical for RPE cells intended for transplantation, since defects in intracellular motility have been shown to promote RPE pathogenesis akin to that found in macular degeneration. To test their capabilities for in-vivo transplantation, we injected the iPSC-RPE cells into the subretinal space of a mouse model of retinal degeneration, and demonstrated that the transplanted cells are capable of rescuing lost RPE function. Conclusions This report documents the successful generation, under GMP-compatible conditions, of human iPSC-RPE cells that possess specific characteristics of healthy RPE. The report adds to a growing literature on the utility of human iPSC-RPE cells for cell culture investigations on pathogenicity and for therapeutic transplantation, by corroborating findings of others, and providing important new information on essential RPE cell biological properties. Electronic supplementary material The online version of this article (doi:10.1186/s13287-017-0652-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Roni A Hazim
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, 100 Stein Plaza, Los Angeles, CA, 90095, USA
| | - Saravanan Karumbayaram
- Department of Microbiology Immunology and Molecular Genetics, Los Angeles, CA, USA. .,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, CA, USA. .,Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA.
| | - Mei Jiang
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, 100 Stein Plaza, Los Angeles, CA, 90095, USA
| | - Anupama Dimashkie
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, CA, USA
| | - Vanda S Lopes
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, 100 Stein Plaza, Los Angeles, CA, 90095, USA
| | - Douran Li
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, 100 Stein Plaza, Los Angeles, CA, 90095, USA.,Department of Molecular Cell and Developmental Biology, Los Angeles, CA, USA
| | - Barry L Burgess
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, 100 Stein Plaza, Los Angeles, CA, 90095, USA
| | - Preethi Vijayaraj
- Department of Pediatrics, David Geffen School of Medicine, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | | | - Jerome A Zack
- Department of Microbiology Immunology and Molecular Genetics, Los Angeles, CA, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA.,Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Donald B Kohn
- Department of Microbiology Immunology and Molecular Genetics, Los Angeles, CA, USA.,Department of Pediatrics, David Geffen School of Medicine, Los Angeles, CA, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Brigitte N Gomperts
- Department of Pediatrics, David Geffen School of Medicine, Los Angeles, CA, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - April D Pyle
- Department of Microbiology Immunology and Molecular Genetics, Los Angeles, CA, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - William E Lowry
- Department of Molecular Cell and Developmental Biology, Los Angeles, CA, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - David S Williams
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, 100 Stein Plaza, Los Angeles, CA, 90095, USA. .,Department of Neurobiology, David Geffen School of Medicine, Los Angeles, CA, USA. .,Molecular Biology Institute, Los Angeles, CA, USA. .,Brain Research Institute, University of California, Los Angeles, CA, USA.
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255
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2016 Glenn A. Fry Award Lecture: Mechanisms and Potential Treatments of Early Age-Related Macular Degeneration. Optom Vis Sci 2017; 94:939-945. [DOI: 10.1097/opx.0000000000001124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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256
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Bergen AA. Nicotinamide, iRPE-in-a dish, and age-related macular degeneration therapy development. Stem Cell Investig 2017; 4:81. [PMID: 29057253 DOI: 10.21037/sci.2017.09.05] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/06/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Arthur A Bergen
- Department of Clinical Genetics and Ophthalmology, Academic Medical Center, Amsterdam, the Netherlands.,Netherlands Institute for Neuroscience (NIN-KNAW), Amsterdam, The Netherlands
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257
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Cammalleri M, Dal Monte M, Locri F, Lardner E, Kvanta A, Rusciano D, André H, Bagnoli P. Efficacy of a Fatty Acids Dietary Supplement in a Polyethylene Glycol-Induced Mouse Model of Retinal Degeneration. Nutrients 2017; 9:nu9101079. [PMID: 28961167 PMCID: PMC5691696 DOI: 10.3390/nu9101079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/18/2017] [Accepted: 09/27/2017] [Indexed: 01/07/2023] Open
Abstract
Current knowledge of the benefits of nutrition supplements for eye pathologies is based largely on the use of appropriate animal models, together with defined dietary supplementation. Here, C57BL6 mice were subretinally injected with polyethylene glycol (PEG)-400, an established model of retinal degeneration with a dry age-related macular degeneration (AMD)-like phenotype, an eye pathology that lacks treatment. In response to PEG-400, markers of the complement system, angiogenesis, inflammation, gliosis, and macrophage infiltration were upregulated in both retinas and retinal pigment epithelium (RPE)/choroids, whereas dietary supplementation with a mixture based on fatty acids counteracted their upregulation. Major effects include a reduction of inflammation, in both retinas and RPE/choroids, and an inhibition of macrophage infiltration in the choroid, yet not in the retina, suggesting a targeted action through the choroidal vasculature. Histological analysis revealed a thinning of the outer nuclear layer (ONL), together with dysregulation of the epithelium layer in response to PEG-400. In addition, immunohistofluorescence demonstrated Müller cell gliosis and macrophage infiltration into subretinal tissues supporting the molecular findings. Reduced ONL thickness, gliosis, and macrophage infiltration were counteracted by the diet supplement. The present data suggest that fatty acids may represent a useful form of diet supplementation to prevent or limit the progression of dry AMD.
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Affiliation(s)
- Maurizio Cammalleri
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
| | - Filippo Locri
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Emma Lardner
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Anders Kvanta
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Dario Rusciano
- Sooft Fidia Pharma, Contrada Molino 17, 63833 Montegiorgio (FM), Italy.
| | - Helder André
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Paola Bagnoli
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
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258
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Clark SJ, Bishop PN. The eye as a complement dysregulation hotspot. Semin Immunopathol 2017; 40:65-74. [PMID: 28948331 PMCID: PMC5794836 DOI: 10.1007/s00281-017-0649-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 08/30/2017] [Indexed: 01/23/2023]
Abstract
Complement turnover is tightly regulated throughout the human body in order to prevent over-activation and subsequent damage from inflammation. In the eye, low-level complement activation is maintained to provide immune tolerance in this immune privileged organ. Conversely, the complement system is suppressed in the cornea to protect it from continuous immunological insult. Over-activation of the complement cascade has been implicated in the disease progression of glaucoma and diabetic retinopathy and is now known to be a central driver in the pathogenesis of age-related macular degeneration (AMD). Indeed, it is with AMD where the most recent and exciting work has been carried out with complement-based therapies entering into clinical trials. However, the success of these trials will depend upon delivering the therapeutics to the correct anatomical sites within the eye, so a full understanding of how complement regulation is compartmentalized in the eye is required, a topic that will be highlighted in this review.
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Affiliation(s)
- Simon J Clark
- Division of Evolution and Genomic Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
| | - Paul N Bishop
- Division of Evolution and Genomic Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.,Manchester Royal Eye Hospital, Manchester Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK
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259
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Ye Z, Li Z, He S. Long non‑coding RNA associated‑competing endogenous RNAs are induced by clusterin in retinal pigment epithelial cells. Mol Med Rep 2017; 16:8399-8405. [PMID: 28944909 DOI: 10.3892/mmr.2017.7606] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 06/30/2017] [Indexed: 11/05/2022] Open
Abstract
Age related macular degeneration is one of the most common causes of vision loss in the elderly. Long noncoding RNAs (lncRNAs) serve important roles in regulating gene expression by acting as competing endogenous RNAs (ceRNAs). However, the roles of specific lncRNAs and their associated ceRNA function induced by clusterin in cultured retinal pigment epithelial (RPE) cells remain to be fully elucidated. Based on high throughput sequencing data from RPE cells treated with or without clusterin, the present study identified differentially expressed mRNAs, lncRNAs and microRNAs (miRNAs). A lncRNA‑mRNA‑microRNA (miRNA) network (ceRNA network) was subsequently constructed based on the bioinformatic database miRanda and miRNA targets database miRTarBase. These results demonstrated the expression pattern of several lncRNAs, and a clear clusterin‑associated ceRNA network in RPE cells, which included 75 lncRNAs and 32 miRNAs in RPE cells induced by clusterin. Collectively, the present study uncovered and characterized via bioinformatics the global properties of the ceRNA network in human RPE cells in response to clusterin. These results may aid in the elucidation of the molecular mechanisms of clusterin in age‑related macular degeneration.
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Affiliation(s)
- Zi Ye
- Department of Ophthalmology, People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Zhaohui Li
- Department of Ophthalmology, People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Shouzhi He
- Department of Ophthalmology, People's Liberation Army General Hospital, Beijing 100853, P.R. China
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260
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Complement factor H in AMD: Bridging genetic associations and pathobiology. Prog Retin Eye Res 2017; 62:38-57. [PMID: 28928087 DOI: 10.1016/j.preteyeres.2017.09.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 09/08/2017] [Accepted: 09/13/2017] [Indexed: 01/28/2023]
Abstract
Age-Related Macular Degeneration (AMD) is a complex multifactorial disease characterized in its early stages by lipoprotein accumulations in Bruch's Membrane (BrM), seen on fundoscopic exam as drusen, and in its late forms by neovascularization ("wet") or geographic atrophy of the Retinal Pigmented Epithelial (RPE) cell layer ("dry"). Genetic studies have strongly supported a relationship between the alternative complement cascade, in particular the common H402 variant in Complement Factor H (CFH) and development of AMD. However, the functional significance of the CFH Y402H polymorphism remains elusive. In this article, we critically review the literature surrounding the functional significance of this polymorphism. Furthermore, based on our group's studies we propose a model in which CFH H402 affects CFH binding to heparan sulfate proteoglycans leading to accelerated lipoprotein accumulation in BrM and drusen progression. We also review the literature on the role of other complement components in AMD pathobiologies, including C3a, C5a and the membrane attack complex (MAC), and on transgenic mouse models developed to interrogate in vivo the effects of the CFH Y402H polymorphism.
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261
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Abstract
Age-related macular degeneration (AMD) and related macular dystrophies (MDs) are a major cause of vision loss. However, the mechanisms underlying their progression remain ill-defined. This is partly due to the lack of disease models recapitulating the human pathology. Furthermore, in vivo studies have yielded limited understanding of the role of specific cell types in the eye vs. systemic influences (e.g., serum) on the disease pathology. Here, we use human induced pluripotent stem cell-retinal pigment epithelium (hiPSC-RPE) derived from patients with three dominant MDs, Sorsby's fundus dystrophy (SFD), Doyne honeycomb retinal dystrophy/malattia Leventinese (DHRD), and autosomal dominant radial drusen (ADRD), and demonstrate that dysfunction of RPE cells alone is sufficient for the initiation of sub-RPE lipoproteinaceous deposit (drusen) formation and extracellular matrix (ECM) alteration in these diseases. Consistent with clinical studies, sub-RPE basal deposits were present beneath both control (unaffected) and patient hiPSC-RPE cells. Importantly basal deposits in patient hiPSC-RPE cultures were more abundant and displayed a lipid- and protein-rich "drusen-like" composition. Furthermore, increased accumulation of COL4 was observed in ECM isolated from control vs. patient hiPSC-RPE cultures. Interestingly, RPE-specific up-regulation in the expression of several complement genes was also seen in patient hiPSC-RPE cultures of all three MDs (SFD, DHRD, and ADRD). Finally, although serum exposure was not necessary for drusen formation, COL4 accumulation in ECM, and complement pathway gene alteration, it impacted the composition of drusen-like deposits in patient hiPSC-RPE cultures. Together, the drusen model(s) of MDs described here provide fundamental insights into the unique biology of maculopathies affecting the RPE-ECM interface.
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262
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Li H, Chintalapudi SR, Jablonski MM. Current drug and molecular therapies for the treatment of atrophic age-related macular degeneration: phase I to phase III clinical development. Expert Opin Investig Drugs 2017; 26:1103-1114. [PMID: 28816076 DOI: 10.1080/13543784.2017.1369042] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Age-related macular degeneration (AMD) is the leading cause of vision loss among the elderly. Atrophic AMD, including early, intermediate and geographic atrophy (GA), accounts for ~90% of all cases. It is a multifactorial degeneration characterized by chronic inflammation, oxidative stress and aging components. Although no FDA-approved treatment yet exists for the late stage of atrophic AMD, multiple pathological mechanisms are partially known and several promising therapies are in various stages of development. Areas covered: Underlying mechanisms that define atrophic AMD will help provide novel therapeutic targets that will address this largely unmet clinical need. The purpose of this paper is to review current promising drugs that are being evaluated in clinical trials. Because no pharmacological treatments are currently available for late stage of atrophic AMD, any new therapy would have extensive market potential. Expert opinion: The number of AMD patients is predicted to increase to ~30 million worldwide by 2020. In response to this enormous unmet clinical need, new promising therapies are being developed and evaluated in clinical trials. We propose that the assessment of novel interventions will also need to consider the genotypes of participants, as the benefit may be determined by polymorphisms in an individual's genetic background.
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Affiliation(s)
- Huiling Li
- a Department of Ophthalmology, The Second Xiangya Hospital , Central South University , Changsha , China
| | - Sumana R Chintalapudi
- b Department of Ophthalmology, The Hamilton Eye Institute , The University of Tennessee Health Science Center , Memphis , TN , USA.,c Department of Anatomy and Neurobiology , The University of Tennessee Health Science Center , Memphis , TN , USA
| | - Monica M Jablonski
- b Department of Ophthalmology, The Hamilton Eye Institute , The University of Tennessee Health Science Center , Memphis , TN , USA.,c Department of Anatomy and Neurobiology , The University of Tennessee Health Science Center , Memphis , TN , USA.,d Department of Pharmaceutical Sciences , The University of Tennessee Health Science Center , Memphis , TN , USA
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263
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Bak M, Sørensen TL, Flachs EM, Zwisler AD, Juel K, Frederiksen H, Hasselbalch HC. Age-Related Macular Degeneration in Patients With Chronic Myeloproliferative Neoplasms. JAMA Ophthalmol 2017; 135:835-843. [PMID: 28655032 DOI: 10.1001/jamaophthalmol.2017.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Importance It has been suggested that systemic inflammation increases the risk of age-related macular degeneration (AMD). Given that chronic immune modulation is present in patients with myeloproliferative neoplasms (MPNs), the risk of AMD in these patients may be increased. Objective To compare the risk of AMD in patients with MPNs with the risk of AMD in matched controls from the general population. Design, Setting, and Participants A nationwide population-based cohort study using Danish registers was conducted of all patients in Denmark who received a diagnosis between January 1, 1994, and December 31, 2013, of essential thrombocythemia, polycythemia vera, myelofibrosis, or unclassifiable MPNs. For each patient, 10 age- and sex-matched controls were included. All patients without prior AMD were followed up from the date of diagnosis (or corresponding entry date for the controls) until the first AMD diagnosis, death or emigration, or December 31, 2013, whichever occurred first. Data analysis was performed from April 1, 2015, to October 31, 2016. Main Outcomes and Measures Incidence of AMD recorded in specialized hospital-based care. The rates and absolute risk of AMD were calculated. Using Cox proportional hazards regression models, smoking and risk-time adjusted hazard ratios (HRs) between patients and controls were calculated. In addition, HRs of neovascular AMD after 2006 were calculated since antivascular endothelial growth factor treatment was introduced nationwide at hospitals thereafter. Results A total of 7958 patients with MPNs (4279 women [53.8%] and 3679 men [46.2%]; mean [SD] age at diagnosis, 66.4 [14.3] years) were included in the study. The rate of AMD per 1000 person-years at risk was 5.2 (95% CI, 4.6-5.9) for patients with MPNs (2628 with essential thrombocythemia, 3063 with polycythemia vera, 547 with myelofibrosis, and 1720 with unclassifiable MPNs) and 4.3 (95% CI, 4.1-4.4) for the 77 445 controls, while the 10-year risk of AMD was 2.4% (95% CI, 2.1%-2.8%) for patients with MPNs and 2.3% (95% CI, 2.2%-2.4%) for the controls. The risk of AMD was increased overall for patients with MPNs (adjusted HR, 1.3; 95% CI, 1.1-1.5), with adjusted HRs for the subtypes of 1.2 (95% CI, 1.0-1.6) for essential thrombocythemia, 1.4 (95% CI, 1.2-1.7) for polycythemia vera, 1.7 (95% CI, 0.8-4.0) for myelofibrosis, and 1.5 (95% CI, 1.1-2.1) for unclassifiable MPNs. In addition, patients with MPNs had a higher risk of neovascular AMD (adjusted HR, 1.4; 95% CI, 1.2-1.6). Conclusions and Relevance Our results suggest that patients with MPNs are at increased risk of AMD, supporting the possibility that systemic inflammation is involved in the pathogenesis of AMD.
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Affiliation(s)
- Marie Bak
- Department of Haematology, Zealand University Hospital, University of Copenhagen, Roskilde, Denmark
| | - Torben Lykke Sørensen
- Department of Ophthalmology, Zealand University Hospital, University of Copenhagen, Roskilde, Denmark
| | - Esben Meulengracht Flachs
- Department of Occupational and Environmental Medicine, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Ann-Dorthe Zwisler
- Danish Knowledge Centre for Rehabilitation and Palliative Care, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Knud Juel
- National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark
| | - Henrik Frederiksen
- Department of Haematology, Odense University Hospital, Odense, Denmark.,Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
| | - Hans Carl Hasselbalch
- Department of Haematology, Zealand University Hospital, University of Copenhagen, Roskilde, Denmark
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Yan F, Wang H, Gao Y, Xu J, Zheng W. Artemisinin Protects Retinal Neuronal Cells against Oxidative Stress and Restores Rat Retinal Physiological Function from Light Exposed Damage. ACS Chem Neurosci 2017; 8:1713-1723. [PMID: 28447781 DOI: 10.1021/acschemneuro.7b00021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Oxidative stress plays a key role in the pathogenesis of age-related macular degeneration (AMD), a leading cause of severe visual loss and blindness in the aging population which lacks any effective treatments currently. In this study, artemisinin, a well-known antimalarial drug was found to suppress hydrogen peroxide (H2O2)-induced cell death in retinal neuronal RGC-5 cells. Artemisinin, in the therapeutically relevant dosage, concentration-dependently attenuated the accumulation of intracellular reactive oxygen species (ROS), increased mitochondrial membrane potential and decreased cell apoptosis in RGC-5 cells induced by H2O2. Western blot analysis showed that artemisinin upregulated the phosphorylation of p38 and extracellular signal-regulated kinases1/2 (ERK1/2) and reversed the inhibitory effect of H2O2 on the phosphorylation of these two kinases. Moreover, protective effect of artemisinin was blocked by the p38 kinase inhibitor PD169316 or ERK1/2 kinase pathway inhibitor PD98059, respectively. In contrast, c-Jun N-terminal kinase inhibitor and rapamycin had no effect in the protective effect of artemisinin. Taken together, these results demonstrated that artemisinin promoted the survival of RGC-5 cells from H2O2 toxicity via the activation of the p38 and ERK1/2 pathways. Interestingly, intravitreous injection of artimisinin, concentration-dependently reversed light exposed-damage (a dry AMD animal model) of rat retinal physiological function detected by flash electroretinogram. These results indicate that artemisinin can protect retinal neuronal functions from H2O2-induced damage in vitro and in vivo and suggest the potential application of artemisinin as a new drug in the treatment of retinal disorders like AMD.
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Affiliation(s)
- Fengxia Yan
- Faculty
of Health Sciences, University of Macau, Taipa, Macau 999078, China
- The
First Affiliated Hospital and Neuroparmacology, School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Haitao Wang
- Faculty
of Health Sciences, University of Macau, Taipa, Macau 999078, China
- School
of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yang Gao
- Zhongshan
Ophthalmic Center, Sun Yat-sen University, Guangzhou 510006, China
| | - Jiangping Xu
- School
of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Wenhua Zheng
- Faculty
of Health Sciences, University of Macau, Taipa, Macau 999078, China
- The
First Affiliated Hospital and Neuroparmacology, School of Pharmaceutical
Sciences, Sun Yat-sen University, Guangzhou 510006, China
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265
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Grossman TR, Carrer M, Shen L, Johnson RB, Hettrick LA, Henry SP, Monia BP, McCaleb ML. Reduction in ocular complement factor B protein in mice and monkeys by systemic administration of factor B antisense oligonucleotide. Mol Vis 2017; 23:561-571. [PMID: 28855795 PMCID: PMC5563462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 08/08/2017] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Age-related macular degeneration (AMD) is the leading cause of permanent vision loss among the elderly in many industrialized countries, and the complement system plays an important role in the pathogenesis of AMD. Inhibition of complement factor B, a key regulator of the alternative pathway, is implicated as a potential therapeutic intervention for AMD. Here we investigated the effect of liver factor B reduction on systemic and ocular factor B levels. METHODS Second-generation antisense oligonucleotides (ASOs) targeting mouse and monkey factor B mRNA were administered by subcutaneous injection to healthy mice or monkeys, and the level of factor B mRNA was assessed in the liver and the eye. In addition, the factor B protein level was determined in plasma and whole eyes from the treated animals. RESULTS Mice and monkeys treated with factor B ASOs demonstrated a robust reduction in liver factor B mRNA levels with no change in ocular factor B mRNA levels. Plasma factor B protein levels were significantly reduced in mice and monkeys treated with factor B ASOs, leading to a dramatic reduction in ocular factor B protein, below the assay detection levels. CONCLUSIONS The results add to the increasing evidence that the liver is the main source of plasma and ocular factor B protein, and demonstrate that reduction of liver factor B mRNA by an ASO results in a significant reduction in plasma and ocular factor B protein levels. The results suggest that inhibition of liver factor B mRNA by factor B ASOs would reduce systemic alternative complement pathway activation and has potential to be used as a novel therapy for AMD.
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266
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Abstract
Recognition and removal of apoptotic and necrotic cells must be efficient and highly controlled to avoid excessive inflammation and autoimmune responses to self. The complement system, a crucial part of innate immunity, plays an important role in this process. Thus, apoptotic and necrotic cells are recognized by complement initiators such as C1q, mannose binding lectin, ficolins, and properdin. This triggers complement activation and opsonization of cells with fragments of C3b, which enhances phagocytosis and thus ensures silent removal. Importantly, the process is tightly controlled by the binding of complement inhibitors C4b-binding protein and factor H, which attenuates late steps of complement activation and inflammation. Furthermore, factor H becomes actively internalized by apoptotic cells, where it catalyzes the cleavage of intracellular C3 to C3b. The intracellularly derived C3b additionally opsonizes the cell surface further supporting safe and fast clearance and thereby aids to prevent autoimmunity. Internalized factor H also binds nucleosomes and directs monocytes into production of anti-inflammatory cytokines upon phagocytosis of such complexes. Disturbances in the complement-mediated clearance of dying cells result in persistence of autoantigens and development of autoimmune diseases like systemic lupus erythematosus, and may also be involved in development of age-related macula degeneration.
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Affiliation(s)
- Myriam Martin
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Anna M Blom
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden.
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267
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Subhi Y, Lykke Sørensen T. New neovascular age-related macular degeneration is associated with systemic leucocyte activity. Acta Ophthalmol 2017; 95:472-480. [PMID: 27860298 DOI: 10.1111/aos.13330] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/07/2016] [Indexed: 12/11/2022]
Abstract
PURPOSE To investigate systemic leucocyte activity in subtypes of age-related macular degeneration (AMD) and onset of neovascular AMD. METHODS Patients with early and late AMD and age-matched control individuals were recruited consecutively, and venous blood was sampled for differential leucocyte counts. Patients with neovascular AMD were grouped based on time of blood sampling in relation to diagnosis of neovascular AMD: diagnosis of new neovascular AMD more than 30 days before blood sampling, within 30 days of blood sampling and more than 30 days after blood sampling. RESULTS Of 347 recruited participants, 330 fulfilled the eligibility criteria (77 age-matched controls, 33 with early AMD, 56 with geographic atrophy and 164 with neovascular AMD). We did not find any differences in the differential counts between patients at different stages of AMD and age-matched control individuals. However, lymphocyte and monocytes-basophils-eosinophils mixed (MXD) counts were both significantly increased in patients with new neovascular AMD. Among these patients; higher MXD correlated with lower BCVA, larger central foveal thickness and larger total lesion size; higher lymphocytes correlated with smaller total lesion size; higher neutrophils correlated with CNV lesion size; and higher neutrophil-to-lymphocyte ratio correlated with larger lesion size. CONCLUSIONS Systemic leucocyte activity is associated with onset of CNV in patients with AMD and correlate with lesion size and BCVA, which suggest that acute systemic immune activity may play a role in neovascular flaring of AMD.
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Affiliation(s)
- Yousif Subhi
- Clinical Eye Research Unit; Department of Ophthalmology; Zealand University Hospital; Roskilde Denmark
- Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Torben Lykke Sørensen
- Clinical Eye Research Unit; Department of Ophthalmology; Zealand University Hospital; Roskilde Denmark
- Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
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268
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Yang P, Skiba NP, Tewkesbury GM, Treboschi VM, Baciu P, Jaffe GJ. Complement-Mediated Regulation of Apolipoprotein E in Cultured Human RPE Cells. Invest Ophthalmol Vis Sci 2017. [PMID: 28632844 PMCID: PMC5482245 DOI: 10.1167/iovs.16-20083] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Purpose. Complement activation is implicated in the pathogenesis of age-related macular degeneration (AMD). Apolipoprotein E (ApoE) and complement activation products such as membrane attack complex (MAC) are present in eyes of individuals with AMD. Herein, we investigated the effect of complement activation on induction of ApoE accumulation in human retinal pigment epithelial (RPE) cells. Methods. Cultured human RPE cells were primed with a complement-fixing antibody followed by treatment with C1q-depleted (C1q-Dep) human serum to elicit alternative pathway complement activation. Controls included anti-C5 antibody-treated serum and heat-inactivated C1q-Dep. Total protein was determined on RPE cell extracts, conditioned media, and extracellular matrix (ECM) by Western blot. ApoE and MAC colocalization was assessed on cultured RPE cells and human eyes by immunofluorescent stain. ApoE mRNA expression was evaluated by quantitative PCR (qPCR). Results. Complement challenge upregulated cell-associated ApoE, but not apolipoprotein A1. ApoE accumulation was blocked by anti-C5 antibody and enhanced by repetitive complement challenge. ApoE mRNA levels were not affected by complement challenge. ApoE was frequently colocalized with MAC in complement-treated cells and drusen from human eyes. ApoE was released into complement-treated conditioned media after a single complement challenge and accumulated on ECM after repetitive complement challenge. Conclusions. Complement challenge induces time-dependent ApoE accumulation in RPE cells. An understanding of the mechanisms by which complement affects RPE ApoE accumulation may help to better explain drusen composition, and provide insights into potential therapeutic targets.
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Affiliation(s)
- Ping Yang
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Nikolai P Skiba
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Grace M Tewkesbury
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Victoria M Treboschi
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Peter Baciu
- Department of Biology, Allergan, Inc., Irvine, California, United States
| | - Glenn J Jaffe
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
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269
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Klingeborn M, Dismuke WM, Bowes Rickman C, Stamer WD. Roles of exosomes in the normal and diseased eye. Prog Retin Eye Res 2017; 59:158-177. [PMID: 28465248 PMCID: PMC5537591 DOI: 10.1016/j.preteyeres.2017.04.004] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 12/21/2022]
Abstract
Exosomes are nanometer-sized vesicles that are released by cells in a controlled fashion and mediate a plethora of extra- and intercellular activities. Some key functions of exosomes include cell-cell communication, immune modulation, extracellular matrix turnover, stem cell division/differentiation, neovascularization and cellular waste removal. While much is known about their role in cancer, exosome function in the many specialized tissues of the eye is just beginning to undergo rigorous study. Here we review current knowledge of exosome function in the visual system in the context of larger bodies of data from other fields, in both health and disease. Additionally, we discuss recent advances in the exosome field including use of exosomes as a therapeutic vehicle, exosomes as a source of biomarkers for disease, plus current standards for isolation and validation of exosome populations. Finally, we use this foundational information about exosomes in the eye as a platform to identify areas of opportunity for future research studies.
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Affiliation(s)
- Mikael Klingeborn
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC 27710, USA
| | - W Michael Dismuke
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC 27710, USA
| | - Catherine Bowes Rickman
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC 27710, USA; Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - W Daniel Stamer
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC 27710, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA.
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270
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Yao Y, Song W, Deng Q, Zhang H, Wang J, Liu H, Zhou Y. General regulatory effects of hypoxia on human cartilage endplate‑derived stem cells: A genome‑wide analysis of differential gene expression and alternative splicing events. Mol Med Rep 2017; 16:3001-3009. [PMID: 28677762 DOI: 10.3892/mmr.2017.6907] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 05/12/2017] [Indexed: 11/06/2022] Open
Abstract
Intervertebral disc (IVD) degeneration of is considered to be initiated by the degeneration of the cartilage endplate (CEP). CEP‑derived stem cells (CESCs) with the capacity for osteochondrogenic differentiation may be responsible for CEP cartilage restoration. As CEP is avascular and hypoxic, and hypoxia can greatly influence biological activities of stem cells, physiological hypoxia may serve important roles in regulating the physiological functions of CESCs. The aim of the present study was to investigate the mechanisms of hypoxia‑regulated CESCs fate by using the Human Transcriptome Array 2.0 system to identify differentially expressed genes (DEGs) and alternatively spliced genes (ASGs) in CESCs cultured under hypoxic and normoxic conditions. The high‑throughput analysis of both DEGs and ASGs were notably enriched in the immune response signal, which so far has not been investigated in IVD cells, due to their avascular nature and low immunogenicity. The present results provided a referential study direction of the mechanisms of hypoxia‑regulated CESC fate at the level of gene expression and alternative splicing, which may aid in our understanding of the processes of CEP degeneration.
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Affiliation(s)
- Yuan Yao
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Weilin Song
- Department of Ophthalmology, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R. China
| | - Qiyue Deng
- Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, P.R. China
| | - Huiyu Zhang
- Department of Stomatology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Jian Wang
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Huan Liu
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Yue Zhou
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
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271
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Liu H, Liu W, Zhou X, Long C, Kuang X, Hu J, Tang Y, Liu L, He J, Huang Z, Fan Y, Jin G, Zhang Q, Shen H. Protective effect of lutein on ARPE-19 cells upon H2O2-induced G2/M arrest. Mol Med Rep 2017; 16:2069-2074. [PMID: 28656238 DOI: 10.3892/mmr.2017.6838] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 03/23/2017] [Indexed: 11/05/2022] Open
Abstract
Oxidative damage is a key factor for the pathogenesis of age‑related macular degeneration (AMD), therefore, anti-oxidative stress is a valuable method for the prevention or treatment of AMD. The aim of the present study was to reveal the protective mechanism of lutein on retinal pigment epithelium (RPE) cells subjected to oxidative stress. Acute retinal pigment epithelial 19 (ARPE‑19) cells were exposed to oxidative stress induced by H2O2 following lutein pretreatment. The activities of caspases, level of intracellular reactive oxygen species (ROS) and cell cycle were analyzed using flow cytometry. The expression levels of cell cycle regulatory proteins and inflammation‑associated genes were detected using western blot and reverse transcription‑polymerase chain reaction analyses, respectively. The data showed that oxidative stress reduced cell viability, and increased total apoptosis and ROS generation, however, lutein prevented cells from oxidative stress‑induced damage. In addition, oxidative damage triggered G2/M phase arrest of the ARPE‑19 cells, which was reversed by lutein in a concentration‑dependent manner, through the activation of cyclin‑dependent kinase 1 and cell division cycle 25C, and degradation of cyclin B1. These results demonstrated that lutein may be an effective antioxidant, which can be applied in the prevention of AMD, or other age-related diseases associated with oxidative damage.
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Affiliation(s)
- Huijun Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Weiwei Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xin Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Chongde Long
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xielan Kuang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Jie Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yan Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Lanying Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Jia He
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Zixin Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yuting Fan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Guorong Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Huangxuan Shen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
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Schäfer N, Grosche A, Schmitt SI, Braunger BM, Pauly D. Complement Components Showed a Time-Dependent Local Expression Pattern in Constant and Acute White Light-Induced Photoreceptor Damage. Front Mol Neurosci 2017; 10:197. [PMID: 28676742 PMCID: PMC5476694 DOI: 10.3389/fnmol.2017.00197] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 06/02/2017] [Indexed: 11/26/2022] Open
Abstract
Background: Photoreceptor cell death due to extensive light exposure and induced oxidative-stress are associated with retinal degeneration. A correlated dysregulation of the complement system amplifies the damaging effects, but the local and time-dependent progression of this mechanism is not thoroughly understood. Methods: Light-induced photoreceptor damage (LD) was induced in Balb/c mice with white light illumination either for 24 h with 1000 lux (constant model) or 0.5 h with 5000 lux (acute model). Complement protein and mRNA expression levels were compared at 1 and 3 days post-LD for C1s, complement factor B (CFB), mannose binding lectin A, mannose-binding protein-associated serine protease 1 (MASP-1), C3, C4, C9, and complement factor P in retina and RPE/choroid. Histological analyses visualized apoptosis, microglia/macrophage migration, gliosis and deposition of the complement activation marker C3d. Systemic anaphylatoxin serum concentrations were determined using an ELISA. Results: Apoptosis, gliosis and microglia/macrophage migration into the outer nuclear layer showed similar patterns in both models. Local complement factor expression revealed an early upregulation of complement factor mRNA in the acute and constant light regimen at 1 day post-treatment for c1s, cfb, masp-1, c3, c4 and c9 in the RPE/choroid. However, intraretinal complement mRNA expression for c1s, cfb, c3 and c4 was increased at 1 day in the constant and at 3 days in the acute model. A corresponding regulation on protein level in the retina following both LD models was observed for C3, which was upregulated at 1 day and correlated with increased C3d staining in the ganglion cell layer and at the RPE. In the RPE/choroid C1s-complex protein detection was increased at 3 days after LD irrespectively of the light intensities used. Conclusion: LD in mouse eyes is correlated with local complement activity. The time-dependent local progression of complement regulation on mRNA and protein levels were equivalent in the acute and constant LD model, except for the intraretinal, time-dependent mRNA expression. Knowing the relative time courses of local complement expression and cellular activity can help to elucidate novel therapeutic options in retinal degeneration indicating at which time point of disease complement has to be rebalanced.
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Affiliation(s)
- Nicole Schäfer
- Department of Ophthalmology, University Hospital RegensburgRegensburg, Germany
| | - Antje Grosche
- Institute of Human Genetics, University RegensburgRegensburg, Germany
| | - Sabrina I Schmitt
- Institute of Human Anatomy and Embryology, University RegensburgRegensburg, Germany
| | - Barbara M Braunger
- Institute of Human Anatomy and Embryology, University RegensburgRegensburg, Germany
| | - Diana Pauly
- Department of Ophthalmology, University Hospital RegensburgRegensburg, Germany
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273
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Prokopiou E, Kolovos P, Kalogerou M, Neokleous A, Papagregoriou G, Deltas C, Malas S, Georgiou T. Therapeutic potential of omega-3 fatty acids supplementation in a mouse model of dry macular degeneration. BMJ Open Ophthalmol 2017; 1:e000056. [PMID: 29354704 PMCID: PMC5721630 DOI: 10.1136/bmjophth-2016-000056] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 04/13/2017] [Accepted: 05/07/2017] [Indexed: 01/27/2023] Open
Abstract
Purpose To evaluate the therapeutic effects of omega-3 (ω-3) and omega-6 (ω-6) fatty acids in the CCL2-/- model of dry age-related macular degeneration (AMD). The blood level of eicosapentaenoic acid (EPA) and arachidonic acid (AA) served to adjust the treatment dosage (AA/EPA=1-1.5). Methods Nine-month-old animals were allocated to different groups: (A) C57BL/6 untreated , (B) CCL2-/- untreated, (C) CCL2-/- treated with ω-3+ω-6, and (D) CCL2-/- treated with ω-3. Treatment was daily administered by gavage for 3 months. Fatty acids analysis was performed and retinas were histologically examined. Three-month-old wild type mice were used for comparison purposes. Real-time PCR and Western blot were performed for retinal inflammatory mediators. Results Increased EPA and decreased AA levels were observed in both blood and retinas in the treatment groups. The outer nuclear layer thickness was increased in groups C (90.0±7.8 μm) and D (125.6±9.8 μm) [corrected] compared with groups B (65.6±3.0 μm) and A (71.1±4.2 μm), and in young mice, it was 98.0±3.9 μm. A decrease in NF-κB expression was noted in the treatment groups. Interleukin (IL) 18 protein levels demonstrated a significant reduction in the ω-3-treated group only. Conclusion Supplementation with ω-3+ω-6 or ω-3 alone (AA/EPA=1-1.5) suggests a protective mechanism in the CCL2-/- animal model of dry AMD, with a more beneficial effect when ω-3 are used alone. Our findings indicated that inflammation is not the only determining factor; perhaps a regenerative process might be involved following administration of ω-3 fatty acids.
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Affiliation(s)
| | | | - Maria Kalogerou
- Ophthalmos Research and Educational Institute, Nicosia, Cyprus
| | | | - Gregory Papagregoriou
- Department of Biological Sciences, Molecular Medicine Research Centre and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Constantinos Deltas
- Department of Biological Sciences, Molecular Medicine Research Centre and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Stavros Malas
- Developmental and Functional Genetics Group, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Tassos Georgiou
- Ophthalmos Research and Educational Institute, Nicosia, Cyprus
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274
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Busch C, Annamalai B, Abdusalamova K, Reichhart N, Huber C, Lin Y, Jo EAH, Zipfel PF, Skerka C, Wildner G, Diedrichs-Möhring M, Rohrer B, Strauß O. Anaphylatoxins Activate Ca 2+, Akt/PI3-Kinase, and FOXO1/FoxP3 in the Retinal Pigment Epithelium. Front Immunol 2017; 8:703. [PMID: 28663750 PMCID: PMC5472091 DOI: 10.3389/fimmu.2017.00703] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/31/2017] [Indexed: 12/20/2022] Open
Abstract
PURPOSE The retinal pigment epithelium (RPE) is a main target for complement activation in age-related macular degeneration (AMD). The anaphylatoxins C3a and C5a have been thought to mostly play a role as chemoattractants for macrophages and immune cells; here, we explore whether they trigger RPE alterations. Specifically, we investigated the RPE as a potential immunoregulatory gate, allowing for active changes in the RPE microenvironment in response to complement. DESIGN In vitro and in vivo analysis of signaling pathways. METHODS Individual activities of and interaction between the two anaphylatoxin receptors were tested in cultured RPE cells by fluorescence microscopy, western blot, and immunohistochemistry. MAIN OUTCOME MEASURES Intracellular free calcium, protein phosphorylation, immunostaining of tissues/cells, and multiplex secretion assay. RESULTS Similar to immune cells, anaphylatoxin exposure resulted in increases in free cytosolic Ca2+, PI3-kinase/Akt activation, FoxP3 and FOXO1 phosphorylation, and cytokine/chemokine secretion. Differential responses were elicited depending on whether C3a and C5a were co-administered or applied consecutively, and response amplitudes in co-administration experiments ranged from additive to driven by C5a (C3a + C5a = C5a) or being smaller than those elicited by C3a alone (C3a + C5a < C3a). CONCLUSION We suggest that this combination of integrative signaling between C3aR and C5aR helps the RPE to precisely adopt its immune regulatory function. These data further contribute to our understanding of AMD pathophysiology.
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Affiliation(s)
- Catharina Busch
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
| | | | - Khava Abdusalamova
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
| | - Nadine Reichhart
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
| | - Christian Huber
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
- Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany
| | - Yuchen Lin
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Emeraldo A. H. Jo
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Gerhild Wildner
- Department of Ophthalmology, Section of Immunobiology, Clinic of the LMU Munich, Munich, Germany
| | - Maria Diedrichs-Möhring
- Department of Ophthalmology, Section of Immunobiology, Clinic of the LMU Munich, Munich, Germany
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, United States
- Ralph H. Johnson VA Medical Center, Division of Research, Charleston, SC, United States
| | - Olaf Strauß
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
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275
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Abstract
The complement system is a vital component of the immune-priveliged human eye that is always active at a low-grade level, preventing harmful intraocular injuries caused by accumulation of turnover products and controlling pathogens to preserve eye homeostasis and vision. The complement system is a double-edged sword that is essential for protection but may also become harmful and contribute to eye pathology. Here, we review the evidence for the involvement of complement system dysregulation in age-related macular degeneration, glaucoma, uveitis, and neuromyelitis optica, highlighting the relationship between morphogical changes and complement system protein expression and regulation in these diseases. The potential benefits of complement inhibition in age-related macular degeneration, glaucoma, uveitis, and neuromyelitis optica are abundant, as are those of further research to improve our understanding of complement-mediated injury in these diseases.
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Affiliation(s)
- Camilla Mohlin
- Linnæus Center of Biomaterials Chemistry, Linnæus University, Kalmar, Sweden
| | - Kerstin Sandholm
- Linnæus Center of Biomaterials Chemistry, Linnæus University, Kalmar, Sweden
| | - Kristina N Ekdahl
- Linnæus Center of Biomaterials Chemistry, Linnæus University, Kalmar, Sweden; Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Bo Nilsson
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
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276
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Diabetic retinopathy and dysregulated innate immunity. Vision Res 2017; 139:39-46. [PMID: 28571700 DOI: 10.1016/j.visres.2017.04.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 04/12/2017] [Accepted: 04/13/2017] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is the progressive degeneration of retinal blood vessels and neurons. Inflammation is known to play an important role in the pathogenesis of DR. During diabetes, metabolic disorder leads to the release of damage-associated molecular patterns (DAMPs) both in the retina and elsewhere in the body. The innate immune system provides the first line of defense against the DAMPs. In the early stages of DR when the blood retinal barrier (BRB) is intact, retinal microglia and the complement system are activated at low levels. This low-level of inflammation (para-inflammation) is believed to be essential to maintain homeostasis and restore functionality. However, prolonged stimulation by DAMPs in the diabetic eye leads to maladaptation of the innate immune system and dysregulated para-inflammation may contribute to DR development. In the advanced stages of DR where immune privilege is comprised, circulating immune cells and serum proteins may infiltrate the retina and participate in retinal chronic inflammation and retinal vascular and neuronal damage. This review discusses how the innate immune system is activated in diabetes and DR. The view also discusses why the protective immune response becomes detrimental in DR.
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277
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Extracellular matrix nitration alters growth factor release and activates bioactive complement in human retinal pigment epithelial cells. PLoS One 2017; 12:e0177763. [PMID: 28505174 PMCID: PMC5432172 DOI: 10.1371/journal.pone.0177763] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/03/2017] [Indexed: 12/18/2022] Open
Abstract
Purpose We have shown previously that non-enzymatic nitration (NEN) of the extracellular matrix (ECM), which serves as a model of Bruch’s membrane (BM) aging, has a profound effect on the behavior of the overlying retinal pigment epithelial (RPE) cells, including altered phagocytic ability, reduced cell adhesion, and inhibition of proliferation. We know that transplanted RPE monolayers will encounter a hostile sub-RPE environment, including age-related alterations in BM that may compromise cell function and survival. Here we use our previous NEN model of BM aging to determine the effects of NEN of the ECM on growth factor release and complement activation in RPE cells. Methods Human induced-pluripotent stem cells (iPSCs) were differentiated into RPE cells, and confirmed by immunohistochemistry, confocal microscopy, and polymerase chain reaction. IPSC-derived RPE cells were plated onto RPE-derived ECM under untreated or nitrite-modified conditions. Cells were cultured for 7 days and barrier function measured by transepithelial resistance (TER). Vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), and complement component C3a were measured using enzyme-linked immunosorbent assay (ELISA). Results On average nitrite-modified ECM increased VEGF release both apically and basally by 0.15 ± 0.014 ng/mL (p <0.0001) and 0.21 ± 0.022 ng/mL (p <0.0001), respectively, in iPSC-derived RPE cells. Nitrite-modified ECM increased PEDF release in iPSC-derived RPE cells apically by 0.16 ± 0.031 ng/mL (p <0.0001), but not basally (0.27 ± 0.015 vs. 0.32 ± 0.029 ng/mL, (p >0.05)). Nitrite-modified ECM increased production of C3a in iPSC-derived RPE cells by 0.52 ± 0.123 ng/mL (p <0.05). Conclusion Nitrite-modified ECM increased VEGF, PEDF release, and C3a production in human iPSC-derived RPE cells. This model demonstrates changes seen in the basement membrane can lead to alterations in the cell biology of the RPE cells that may be related to the development of age-related macular degeneration.
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278
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A review of human diseases caused or exacerbated by aberrant complement activation. Neurobiol Aging 2017; 52:12-22. [DOI: 10.1016/j.neurobiolaging.2016.12.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 11/15/2016] [Accepted: 12/18/2016] [Indexed: 12/14/2022]
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279
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Age-related macular degeneration in a randomized controlled trial of low-dose aspirin: Rationale and study design of the ASPREE-AMD study. Contemp Clin Trials Commun 2017; 6:105-114. [PMID: 28736754 PMCID: PMC5518696 DOI: 10.1016/j.conctc.2017.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Purpose Although aspirin therapy is used widely in older adults for prevention of cardiovascular disease, its impact on the incidence, progression and severity of age-related macular degeneration (AMD) is uncertain. The effect of low-dose aspirin on the course of AMD will be evaluated in this clinical trial. Design A sub-study of the ‘ASPirin in Reducing Events in the Elderly’ (ASPREE) trial, ASPREE-AMD is a 5-year follow-up double-blind, placebo-controlled, randomized trial of the effect of 100 mg daily aspirin on the course of AMD in 5000 subjects aged 70 years or older, with normal cognitive function and without cardiovascular disease at baseline. Non-mydriatic fundus photography will be performed at baseline, 3-year and 5-year follow-up to determine AMD status. Primary outcome measures The incidence and progression of AMD. Exploratory analyses will determine whether aspirin affects the risk of retinal hemorrhage in late AMD, and whether other factors, such as genotype, systemic disease, inflammatory biomarkers, influence the effect of aspirin on AMD. Conclusion The study findings will be of significant clinical and public interest due to a potential to identify a possible low cost therapy for preventing AMD worldwide and to determine risk/benefit balance of the aspirin usage by the AMD-affected elderly. The ASPREE-AMD study provides a unique opportunity to determine the effect of aspirin on AMD incidence and progression, by adding retinal imaging to an ongoing, large-scale primary prevention randomized clinical trial.
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280
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The impact of oxidative stress and inflammation on RPE degeneration in non-neovascular AMD. Prog Retin Eye Res 2017; 60:201-218. [PMID: 28336424 DOI: 10.1016/j.preteyeres.2017.03.002] [Citation(s) in RCA: 495] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly specialized, unique epithelial cell that interacts with photoreceptors on its apical side and with Bruch's membrane and the choriocapillaris on its basal side. Due to vital functions that keep photoreceptors healthy, the RPE is essential for maintaining vision. With aging and the accumulated effects of environmental stresses, the RPE can become dysfunctional and die. This degeneration plays a central role in age-related macular degeneration (AMD) pathobiology, the leading cause of blindness among the elderly in western societies. Oxidative stress and inflammation have both physiological and potentially pathological roles in RPE degeneration. Given the central role of the RPE, this review will focus on the impact of oxidative stress and inflammation on the RPE with AMD pathobiology. Physiological sources of oxidative stress as well as unique sources from photo-oxidative stress, the phagocytosis of photoreceptor outer segments, and modifiable factors such as cigarette smoking and high fat diet ingestion that can convert oxidative stress into a pathological role, and the negative impact of impairing the cytoprotective roles of mitochondrial dynamics and the Nrf2 signaling system on RPE health in AMD will be discussed. Likewise, the response by the innate immune system to an inciting trigger, and the potential role of local RPE production of inflammation, as well as a potential role for damage by inflammation with chronicity if the inciting trigger is not neutralized, will be debated.
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281
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Adamus G. Can innate and autoimmune reactivity forecast early and advance stages of age-related macular degeneration? Autoimmun Rev 2017; 16:231-236. [PMID: 28137479 PMCID: PMC5334174 DOI: 10.1016/j.autrev.2017.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 11/03/2016] [Indexed: 01/17/2023]
Abstract
Age-related macular degeneration (AMD) is a major cause of central vision loss in persons over 55years of age in developed countries. AMD is a complex disease in which genetic, environmental and inflammatory factors influence its onset and progression. Elevation in serum anti-retinal autoantibodies, plasma and local activation of complement proteins of the alternative pathway, and increase in secretion of proinflammatory cytokines have been seen over the course of disease. Genetic studies of AMD patients confirmed that genetic variants affecting the alternative complement pathway have a major influence on AMD risk. Because the heterogeneity of this disease, there is no sufficient strategy to identify the disease onset and progression sole based eye examination, thus identification of reliable serological biomarkers for diagnosis, prognosis and response to treatment by sampling patient's blood is necessary. This review provides an outline of the current knowledge on possible serological (autoantibodies, complement factors, cytokines, chemokines) and related genetic biomarkers relevant to the pathology of AMD, and discusses their application for prediction of disease activity and prognosis in AMD.
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Affiliation(s)
- Grazyna Adamus
- Ocular Immunology Laboratory, Casey Eye Institute, School of Medicine, Oregon Health and Science University, Portland, OR, USA.
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282
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Calippe B, Augustin S, Beguier F, Charles-Messance H, Poupel L, Conart JB, Hu SJ, Lavalette S, Fauvet A, Rayes J, Levy O, Raoul W, Fitting C, Denèfle T, Pickering MC, Harris C, Jorieux S, Sullivan PM, Sahel JA, Karoyan P, Sapieha P, Guillonneau X, Gautier EL, Sennlaub F. Complement Factor H Inhibits CD47-Mediated Resolution of Inflammation. Immunity 2017; 46:261-272. [DOI: 10.1016/j.immuni.2017.01.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 11/20/2016] [Accepted: 12/12/2016] [Indexed: 12/16/2022]
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283
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Local complement activation in aqueous humor in patients with age-related macular degeneration. Eye (Lond) 2017; 31:810-813. [PMID: 28128795 DOI: 10.1038/eye.2016.328] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/18/2016] [Indexed: 01/30/2023] Open
Abstract
PurposeTo investigate complement activation in aqueous humor and in plasma of patients with neovascular age-related macular degeneration (nAMD).Patients and methodsAqueous humor and EDTA-plasma of 31 nAMD patients and 30 age-matched controls was collected. The levels of the complement factor 3 (C3), the regulators factor H (FH), and factor I (FI), and of the complement activation products Ba, C3a, and the terminal complement complex (sC5b-9) were measured. Associations between complement levels and phenotype were determined using Mann-Whitney U-test.ResultsIn plasma, no significant differences were found between the nAMD group and the control group. In aqueous humor, significantly increased levels of Ba (P=0.002), and C3a (P=0.002) indicate local complement activation in nAMD patients and a trend for a concomitant upregulation of the complement regulators FH (P=0.02) and FI (P=0.04).ConclusionsOur findings provide strong evidence for a local complement dysregulation in nAMD patients.
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284
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Abstract
PURPOSE OF REVIEW The following review describes the recent evidence regarding the effect of cataract surgery on age-related macular degeneration (AMD). RECENT FINDINGS For patients with both visually significant cataracts and AMD, recent evidence supports the role of cataract surgery with reports demonstrating improved visual acuity, absence of significant disease progression, and improved quality of life. SUMMARY Recent evidence does not find cataract surgery to cause or worsen AMD.
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285
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Chung WH, van Dijk EHC, Mohabati D, Dijkman G, Yzer S, de Jong EK, Fauser S, Schlingemann RO, Hoyng CB, Boon CJF. Neovascular age-related macular degeneration without drusen in the fellow eye: clinical spectrum and therapeutic outcome. Clin Ophthalmol 2017; 11:63-70. [PMID: 28053502 PMCID: PMC5189970 DOI: 10.2147/opth.s122568] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose To investigate the clinical characteristics and therapeutic outcome of patients with neovascular age-related macular degeneration (nAMD) in 1 eye, without drusen in the fellow eye. Patients and methods Medical records of 381 patients were analyzed to identify the cases. The main outcomes included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA) and change in central retinal thickness (CRT). These parameters were reviewed at baseline, first follow-up visit, and after 6, 12, and 24 months. Results Out of 381 patients, 29 cases (8%) were included (of whom 3 had polypoidal choroidal vasculopathy [PCV]) who were treated with anti-vascular endothelial growth factor (anti-VEGF) therapy which was supplemented by photodynamic therapy (PDT) in the PCV patients. Overall, no statistically significant change in mean BCVA was observed during follow-up. BCVA improved or remained stable (defined as a gain in BCVA, a stable BCVA, or a loss of <5 ETDRS letters) in 22 patients (76%), and 7 patients (23%) had lost ≥5 ETDRS letters at final follow-up. A gain of ≥15 ETDRS letters at final follow-up was seen in 5 patients (17%). Mean CRT had decreased significantly with 99 µm (P<0.001) at 24 months after the initial visit. Conclusion There is a clinical spectrum of nAMD that is not associated with drusen in the fellow eye. Patients with nAMD without drusen in the fellow eye respond to anti-VEGF treatment and, in cases of PCV, to supplemental PDT. The pathophysiology of this spectrum of nAMD may be different from drusen-associated age-related macular degeneration.
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Affiliation(s)
- Wing H Chung
- Department of Ophthalmology, Leiden University Medical Center, Leiden
| | - Elon H C van Dijk
- Department of Ophthalmology, Leiden University Medical Center, Leiden
| | - Danial Mohabati
- Department of Ophthalmology, Leiden University Medical Center, Leiden
| | - Greet Dijkman
- Department of Ophthalmology, Leiden University Medical Center, Leiden
| | | | - Eiko K de Jong
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Sascha Fauser
- Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany
| | - Reinier O Schlingemann
- Department of Ophthalmology; Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center; Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden; Department of Ophthalmology
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286
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Lynn SA, Keeling E, Munday R, Gabha G, Griffiths H, Lotery AJ, Ratnayaka JA. The complexities underlying age-related macular degeneration: could amyloid beta play an important role? Neural Regen Res 2017; 12:538-548. [PMID: 28553324 PMCID: PMC5436342 DOI: 10.4103/1673-5374.205083] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Age-related macular degeneration (AMD) causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer's-linked amyloid beta (Aβ) group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer's disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for late-stage AMD.
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Affiliation(s)
- Savannah A Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Rosie Munday
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Gagandeep Gabha
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Helen Griffiths
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,Eye Unit, University Southampton NHS Trust, Southampton, United Kingdom
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
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287
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McKay GJ, Young IS, McGinty A, Bentham GC, Chakravarthy U, Rahu M, Seland J, Soubrane G, Tomazzoli L, Topouzis F, Vioque J, de Jong PT, Fletcher AE. Associations between Serum Vitamin D and Genetic Variants in Vitamin D Pathways and Age-Related Macular Degeneration in the European Eye Study. Ophthalmology 2017; 124:90-96. [DOI: 10.1016/j.ophtha.2016.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/09/2016] [Accepted: 09/09/2016] [Indexed: 12/25/2022] Open
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288
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Del Amo EM, Rimpelä AK, Heikkinen E, Kari OK, Ramsay E, Lajunen T, Schmitt M, Pelkonen L, Bhattacharya M, Richardson D, Subrizi A, Turunen T, Reinisalo M, Itkonen J, Toropainen E, Casteleijn M, Kidron H, Antopolsky M, Vellonen KS, Ruponen M, Urtti A. Pharmacokinetic aspects of retinal drug delivery. Prog Retin Eye Res 2016; 57:134-185. [PMID: 28028001 DOI: 10.1016/j.preteyeres.2016.12.001] [Citation(s) in RCA: 410] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/25/2016] [Accepted: 12/01/2016] [Indexed: 12/14/2022]
Abstract
Drug delivery to the posterior eye segment is an important challenge in ophthalmology, because many diseases affect the retina and choroid leading to impaired vision or blindness. Currently, intravitreal injections are the method of choice to administer drugs to the retina, but this approach is applicable only in selected cases (e.g. anti-VEGF antibodies and soluble receptors). There are two basic approaches that can be adopted to improve retinal drug delivery: prolonged and/or retina targeted delivery of intravitreal drugs and use of other routes of drug administration, such as periocular, suprachoroidal, sub-retinal, systemic, or topical. Properties of the administration route, drug and delivery system determine the efficacy and safety of these approaches. Pharmacokinetic and pharmacodynamic factors determine the required dosing rates and doses that are needed for drug action. In addition, tolerability factors limit the use of many materials in ocular drug delivery. This review article provides a critical discussion of retinal drug delivery, particularly from the pharmacokinetic point of view. This article does not include an extensive review of drug delivery technologies, because they have already been reviewed several times recently. Instead, we aim to provide a systematic and quantitative view on the pharmacokinetic factors in drug delivery to the posterior eye segment. This review is based on the literature and unpublished data from the authors' laboratory.
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Affiliation(s)
- Eva M Del Amo
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Anna-Kaisa Rimpelä
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Emma Heikkinen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Otto K Kari
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Eva Ramsay
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Tatu Lajunen
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Mechthild Schmitt
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Laura Pelkonen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Madhushree Bhattacharya
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Dominique Richardson
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Astrid Subrizi
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Tiina Turunen
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Mika Reinisalo
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Jaakko Itkonen
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Elisa Toropainen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Marco Casteleijn
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Heidi Kidron
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Maxim Antopolsky
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | | | - Marika Ruponen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Arto Urtti
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland; School of Pharmacy, University of Eastern Finland, Kuopio, Finland.
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289
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Ocular neovascular-related diseases: immunological mechanisms of development and the potential of anti-angiogenic therapy. OPHTHALMOLOGY JOURNAL 2016. [DOI: 10.17816/ov9458-67] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The paper adresses three ocular diseases - “wet” type of age-related macular degeneration, diabetic macular edema and neovascular glaucoma, which have similar neovascular changes and immunological disorders. The key moment of neovascularization development is an imbalance between pro- and anti-angiogenic factors. Particular attention is paid to vascular endothelial growth factor (VEGF-A), pigment epithelial derived factor (PEDF), transforming growth factor-beta (ТGF-β). The paper discusses the “immune privilege” of the eye, ACAID phenomenon, aspects of choroidal neovascularization pathogenesis, inflammation as an important part of neovascularization and the protective response to endogenous and exogenous damage, as well as complement system’s disorders, cytokine status impairment and autoimmune mechanisms. Laser treatment is widely used for treatment of neovascular diseases, but pharmacotherapy is very important too. Anti-angiogenic therapy is extremely promising and is held to provide regression of the newly-formed vasculature and/or normalization of newly formed blood vessels structure and suppress the functional activity of a key proangiogenic factor VEGF-A. Pegaptanib, ranibizumab and bevacizumab are discussed, and results of international clinical trials MARINA, ANCHOR, FOCUS, PrONTO, IVAN, CATT, RESTORE are provided.
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290
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Parente R, Clark SJ, Inforzato A, Day AJ. Complement factor H in host defense and immune evasion. Cell Mol Life Sci 2016; 74:1605-1624. [PMID: 27942748 PMCID: PMC5378756 DOI: 10.1007/s00018-016-2418-4] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 12/30/2022]
Abstract
Complement is the major humoral component of the innate immune system. It recognizes pathogen- and damage-associated molecular patterns, and initiates the immune response in coordination with innate and adaptive immunity. When activated, the complement system unleashes powerful cytotoxic and inflammatory mechanisms, and thus its tight control is crucial to prevent damage to host tissues and allow restoration of immune homeostasis. Factor H is the major soluble inhibitor of complement, where its binding to self markers (i.e., particular glycan structures) prevents complement activation and amplification on host surfaces. Not surprisingly, mutations and polymorphisms that affect recognition of self by factor H are associated with diseases of complement dysregulation, such as age-related macular degeneration and atypical haemolytic uremic syndrome. In addition, pathogens (i.e., non-self) and cancer cells (i.e., altered-self) can hijack factor H to evade the immune response. Here we review recent (and not so recent) literature on the structure and function of factor H, including the emerging roles of this protein in the pathophysiology of infectious diseases and cancer.
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Affiliation(s)
- Raffaella Parente
- Humanitas Clinical and Research Center, Via Manzoni 56, Rozzano, 20089, Milan, Italy
| | - Simon J Clark
- Division of Evolution and Genomic Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Antonio Inforzato
- Humanitas Clinical and Research Center, Via Manzoni 56, Rozzano, 20089, Milan, Italy. .,Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129, Milan, Italy.
| | - Anthony J Day
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
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291
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Proangiogenic characteristics of activated macrophages from patients with age-related macular degeneration. Neurobiol Aging 2016; 51:71-82. [PMID: 28039766 DOI: 10.1016/j.neurobiolaging.2016.11.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/23/2016] [Accepted: 11/30/2016] [Indexed: 12/12/2022]
Abstract
Macrophages were previously implicated in the pathogenesis of neovascular age-related macular degeneration (nvAMD). It is unclear if a specific macrophage phenotype is associated with nvAMD, and if macrophages from nvAMD patients are more pathogenic as compared with controls. To address these issues, we evaluated macrophages derived from peripheral blood monocytes of nvAMD patients and age-matched controls. Macrophages were assessed in terms of their expression profile and of their angiogenic potential in the choroid sprouting assay and the rat model of laser-induced choroidal neovascularization. Results showed a proangiogenic and inflammatory gene and protein expression profiles in classic (M[IFNγ and LPS]) and alternative (M[IL-4 and IL-13]) polarized macrophages. Furthermore, activated macrophages, particularly of the M(IFNγ and LPS) phenotype from nvAMD patients, were proangiogenic ex vivo and in vivo. These findings implicate activated human macrophages, particularly M(IFNγ and LPS) macrophages from nvAMD patients, in nvAMD. Further research is required to determine whether activated macrophages can serve as therapeutic targets in nvAMD.
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292
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Ong OTW, Young LJ, Old JM. Sequences and expression of pathway-specific complement components in developing red-tailed phascogale (Phascogale calura). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 65:314-320. [PMID: 27514577 DOI: 10.1016/j.dci.2016.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/06/2016] [Accepted: 08/06/2016] [Indexed: 06/06/2023]
Abstract
Marsupials are born immunologically premature, relying on cells and molecules in maternal milk for immune protection. Both immunoglobulin and complement proteins have been identified in marsupial milk, but the expression of specific complement proteins remains largely unexplored. We report partial cDNA sequences for two complement-activating proteins, C3, C1r, CFP and MASP2, in liver tissues from red-tailed phascogale (Phascogale calura). Conservation of functionally relevant motifs were identified in the translated cDNA sequences from phascogale C3, CFP and MASP2 and their eutherian homologues. Gene expression of representative molecules from each of the major complement pathways was also investigated in whole body tissues from 1 to 18 day old animals and liver tissues from 31-day to 14-month old animals. Average complement expression in whole bodies and liver tissues of C1r, CFP, MASP2 and C3 increased significantly in juveniles compared to pouch young, presumably due to the maturation of the young's own complement system. Comparing expression in liver tissues only, we found that the average CFP expression were higher in pouch young compared to juveniles, while results were still statistically similar to the average expression of all tissues for C1r, MASP2 and C3. The average complement expression then significantly decreased as the animals aged into adulthood.
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Affiliation(s)
- Oselyne T W Ong
- School of Science and Health, Hawkesbury, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Lauren J Young
- School of Science and Health, Hawkesbury, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Julie M Old
- School of Science and Health, Hawkesbury, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia.
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293
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Ricklin D, Reis ES, Mastellos DC, Gros P, Lambris JD. Complement component C3 - The "Swiss Army Knife" of innate immunity and host defense. Immunol Rev 2016; 274:33-58. [PMID: 27782325 PMCID: PMC5427221 DOI: 10.1111/imr.12500] [Citation(s) in RCA: 273] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
As a preformed defense system, complement faces a delicate challenge in providing an immediate, forceful response to pathogens even at first encounter, while sparing host cells in the process. For this purpose, it engages a tightly regulated network of plasma proteins, cell surface receptors, and regulators. Complement component C3 plays a particularly versatile role in this process by keeping the cascade alert, acting as a point of convergence of activation pathways, fueling the amplification of the complement response, exerting direct effector functions, and helping to coordinate downstream immune responses. In recent years, it has become evident that nature engages the power of C3 not only to clear pathogens but also for a variety of homeostatic processes ranging from tissue regeneration and synapse pruning to clearing debris and controlling tumor cell progression. At the same time, its central position in immune surveillance makes C3 a target for microbial immune evasion and, if improperly engaged, a trigger point for various clinical conditions. In our review, we look at the versatile roles and evolutionary journey of C3, discuss new insights into the molecular basis for C3 function, provide examples of disease involvement, and summarize the emerging potential of C3 as a therapeutic target.
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Affiliation(s)
- Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Edimara S Reis
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Dimitrios C Mastellos
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
- National Center for Scientific Research 'Demokritos', Athens, Greece
| | - Piet Gros
- Utrecht University, Utrecht, The Netherlands
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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294
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Mohan RR, Cabrera AP, Harrison RES, Gorham RD, Johnson LV, Ghosh K, Morikis D. Peptide redesign for inhibition of the complement system: Targeting age-related macular degeneration. Mol Vis 2016; 22:1280-1290. [PMID: 27829783 PMCID: PMC5082644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 10/24/2016] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To redesign a complement-inhibiting peptide with the potential to become a therapeutic for dry and wet age-related macular degeneration (AMD). METHODS We present a new potent peptide (Peptide 2) of the compstatin family. The peptide is developed by rational design, based on a mechanistic binding hypothesis, and structural and physicochemical properties derived from molecular dynamics (MD) simulation. The inhibitory activity, efficacy, and solubility of Peptide 2 are evaluated using a hemolytic assay, a human RPE cell-based assay, and ultraviolet (UV) absorption properties, respectively, and compared to the respective properties of its parent peptide (Peptide 1). RESULTS The sequence of Peptide 2 contains an arginine-serine N-terminal extension (a characteristic of parent Peptide 1) and a novel 8-polyethylene glycol (PEG) block C-terminal extension. Peptide 2 has significantly improved aqueous solubility compared to Peptide 1 and comparable complement inhibitory activity. In addition, Peptide 2 is more efficacious in inhibiting complement activation in a cell-based model that mimics the pathobiology of dry AMD. CONCLUSIONS We have designed a new peptide analog of compstatin that combines N-terminal polar amino acid extensions and C-terminal PEGylation extensions. This peptide demonstrates significantly improved aqueous solubility and complement inhibitory efficacy, compared to the parent peptide. The new peptide overcomes the aggregation limitation for clinical translation of previous compstatin analogs and is a candidate to become a therapeutic for the treatment of AMD.
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Affiliation(s)
- Rohith R. Mohan
- Department of Bioengineering, University of California, Riverside, CA
| | - Andrea P. Cabrera
- Department of Bioengineering, University of California, Riverside, CA
| | | | - Ronald D. Gorham
- Department of Bioengineering, University of California, Riverside, CA
| | - Lincoln V. Johnson
- Center for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, CA
| | - Kaustabh Ghosh
- Department of Bioengineering, University of California, Riverside, CA
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, CA
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295
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Xu H, Chen M. Targeting the complement system for the management of retinal inflammatory and degenerative diseases. Eur J Pharmacol 2016; 787:94-104. [PMID: 26948311 PMCID: PMC5026403 DOI: 10.1016/j.ejphar.2016.03.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/12/2016] [Accepted: 03/01/2016] [Indexed: 12/20/2022]
Abstract
The retina, an immune privileged tissue, has specialized immune defense mechanisms against noxious insults that may exist in diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), uveoretinitis and glaucoma. The defense system consists of retinal innate immune cells (including microglia, perivascular macrophages, and a small population of dendritic cells) and the complement system. Under normal aging conditions, retinal innate immune cells and the complement system undergo a low-grade activation (parainflammation) which is important for retinal homeostasis. In disease states such as AMD and DR, the parainflammatory response is dysregulated and develops into detrimental chronic inflammation. Complement activation in the retina is an important part of chronic inflammation and may contribute to retinal pathology in these disease states. Here, we review the evidence that supports the role of uncontrolled or dysregulated complement activation in various retinal degenerative and angiogenic conditions. We also discuss current strategies that are used to develop complement-based therapies for retinal diseases such as AMD. The potential benefits of complement inhibition in DR, uveoretinitis and glaucoma are also discussed, as well as the need for further research to better understand the mechanisms of complement-mediated retinal damage in these disease states.
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Affiliation(s)
- Heping Xu
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Queen's University Belfast, UK.
| | - Mei Chen
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Queen's University Belfast, UK.
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296
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Kam JH, Jeffery G. To unite or divide: mitochondrial dynamics in the murine outer retina that preceded age related photoreceptor loss. Oncotarget 2016; 6:26690-701. [PMID: 26393878 PMCID: PMC4694945 DOI: 10.18632/oncotarget.5614] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 08/27/2015] [Indexed: 12/18/2022] Open
Abstract
Mitochondrial function declines with age and is associated with age-related disorders and cell death. In the retina this is critical as photoreceptor energy demands are the greatest in the body and aged cell loss large (~30%). But mitochondria can fuse or divide to accommodate changing demands. We explore ageing mitochondrial dynamics in young (1 month) and old (12 months) mouse retina, investigating changes in mitochondrial fission (Fis1) and fusion (Opa1) proteins, cytochrome C oxidase (COX III), which reflects mitochondrial metabolic status, and heat shock protein 60 (Hsp60) that is a mitochondrial chaperon for protein folding.Western blots showed each protein declined with age. However, within this, immunostaining revealed increases of around 50% in Fis1 and Opa1 in photoreceptor inner segments (IS). Electron microscope analysis revealed mitochondrial fragmentation with age and marked changes in morphology in IS, consistent with elevated dynamics. COX III declined by approximately 30% in IS, but Hsp60 reductions were around 80% in the outer plexiform layer.Our results are consistent with declining mitochondrial metabolism. But also with increased photoreceptor mitochondrial dynamics that differ from other retinal regions, perhaps reflecting attempts to maintain function. These changes are the platform for age related photoreceptor loss initiated after 12 months.
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Affiliation(s)
- Jaimie Hoh Kam
- Institute of Ophthalmology, University College London, London, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, London, UK
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297
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Lyzogubov VV, Bora PS, Wu X, Horn LE, de Roque R, Rudolf XV, Atkinson JP, Bora NS. The Complement Regulatory Protein CD46 Deficient Mouse Spontaneously Develops Dry-Type Age-Related Macular Degeneration-Like Phenotype. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:2088-2104. [PMID: 27295359 PMCID: PMC4973660 DOI: 10.1016/j.ajpath.2016.03.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 11/20/2022]
Abstract
In the mouse, membrane cofactor protein (CD46), a key regulator of the alternative pathway of the complement system, is only expressed in the eye and on the inner acrosomal membrane of spermatozoa. We noted that although Cd46(-/-) mice have normal systemic alternative pathway activating ability, lack of CD46 leads to dysregulated complement activation in the eye, as evidenced by increased deposition of C5b-9 in the retinal pigment epithelium (RPE) and choroid. A knockout of CD46 induced the following cardinal features of human dry age-related macular degeneration (AMD) in 12-month-old male and female mice: accumulation of autofluorescent material in and hypertrophy of the RPE, dense deposits in and thickening of Bruch's membrane, loss of photoreceptors, cells in subretinal space, and a reduction of choroidal vessels. Collectively, our results demonstrate spontaneous age-related degenerative changes in the retina, RPE, and choroid of Cd46(-/-) mice that are consistent with human dry AMD. These findings provide the exciting possibility of using Cd46(-/-) mice as a convenient and reliable animal model for dry AMD. Having such a relatively straight-forward model for dry AMD should provide valuable insights into pathogenesis and a test model system for novel drug targets. More important, tissue-specific expression of CD46 gives the Cd46(-/-) mouse model of dry AMD a unique advantage over other mouse models using knockout strains.
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Affiliation(s)
- Valeriy V Lyzogubov
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Puran S Bora
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Xiaobo Wu
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Leah E Horn
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Ryan de Roque
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; University of Arkansas for Medical Sciences, College of Medicine, Little Rock, Arkansas
| | - Xeniya V Rudolf
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - John P Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Nalini S Bora
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
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298
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Protective responses to sublytic complement in the retinal pigment epithelium. Proc Natl Acad Sci U S A 2016; 113:8789-94. [PMID: 27432952 DOI: 10.1073/pnas.1523061113] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The retinal pigment epithelium (RPE) is a key site of injury in inherited and age-related macular degenerations. Abnormal activation of the complement system is a feature of these blinding diseases, yet how the RPE combats complement attack is poorly understood. The complement cascade terminates in the cell-surface assembly of membrane attack complexes (MACs), which promote inflammation by causing aberrant signal transduction. Here, we investigated mechanisms crucial for limiting MAC assembly and preserving cellular integrity in the RPE and asked how these are compromised in models of macular degeneration. Using polarized primary RPE and the pigmented Abca4(-/-) Stargardt disease mouse model, we provide evidence for two protective responses occurring within minutes of complement attack, which are essential for maintaining mitochondrial health in the RPE. First, accelerated recycling of the membrane-bound complement regulator CD59 to the RPE cell surface inhibits MAC formation. Second, fusion of lysosomes with the RPE plasma membrane immediately after complement attack limits sustained elevations in intracellular calcium and prevents mitochondrial injury. Cholesterol accumulation in the RPE, induced by vitamin A dimers or oxidized LDL, inhibits these defense mechanisms by activating acid sphingomyelinase (ASMase), which increases tubulin acetylation and derails organelle traffic. Defective CD59 recycling and lysosome exocytosis after complement attack lead to mitochondrial fragmentation and oxidative stress in the RPE. Drugs that stimulate cholesterol efflux or inhibit ASMase restore both these critical safeguards in the RPE and avert complement-induced mitochondrial injury in vitro and in Abca4(-/-) mice, indicating that they could be effective therapeutic approaches for macular degenerations.
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299
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Correspondence. Retina 2016; 36:e70-1. [DOI: 10.1097/iae.0000000000001153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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300
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Khan KN, Mahroo OA, Khan RS, Mohamed MD, McKibbin M, Bird A, Michaelides M, Tufail A, Moore AT. Differentiating drusen: Drusen and drusen-like appearances associated with ageing, age-related macular degeneration, inherited eye disease and other pathological processes. Prog Retin Eye Res 2016; 53:70-106. [DOI: 10.1016/j.preteyeres.2016.04.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 04/24/2016] [Accepted: 04/27/2016] [Indexed: 12/11/2022]
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