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Murenu E, Gerhardt MJ, Biel M, Michalakis S. More than meets the eye: The role of microglia in healthy and diseased retina. Front Immunol 2022; 13:1006897. [PMID: 36524119 PMCID: PMC9745050 DOI: 10.3389/fimmu.2022.1006897] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 11/11/2022] [Indexed: 11/30/2022] Open
Abstract
Microglia are the main resident immune cells of the nervous system and as such they are involved in multiple roles ranging from tissue homeostasis to response to insults and circuit refinement. While most knowledge about microglia comes from brain studies, some mechanisms have been confirmed for microglia cells in the retina, the light-sensing compartment of the eye responsible for initial processing of visual information. However, several key pieces of this puzzle are still unaccounted for, as the characterization of retinal microglia has long been hindered by the reduced population size within the retina as well as the previous lack of technologies enabling single-cell analyses. Accumulating evidence indicates that the same cell type may harbor a high degree of transcriptional, morphological and functional differences depending on its location within the central nervous system. Thus, studying the roles and signatures adopted specifically by microglia in the retina has become increasingly important. Here, we review the current understanding of retinal microglia cells in physiology and in disease, with particular emphasis on newly discovered mechanisms and future research directions.
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Affiliation(s)
- Elisa Murenu
- Department of Ophthalmology, Klinikum der Ludwig-Maximilians-Universität München, Munich, Germany,*Correspondence: Elisa Murenu, ; ; Stylianos Michalakis,
| | | | - Martin Biel
- Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Department of Ophthalmology, Klinikum der Ludwig-Maximilians-Universität München, Munich, Germany,*Correspondence: Elisa Murenu, ; ; Stylianos Michalakis,
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2
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Vallée A. Curcumin and Wnt/β‑catenin signaling in exudative age‑related macular degeneration (Review). Int J Mol Med 2022; 49:79. [PMID: 35445729 PMCID: PMC9083851 DOI: 10.3892/ijmm.2022.5135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/11/2022] [Indexed: 11/06/2022] Open
Abstract
Curcumin is a natural product widely used due to its pharmacological effects. Nevertheless, only a limited number of studies concerning the effects of curcumin on exudative age‑related macular degeneration (AMD) is currently available. Since ophthalmic diseases, including exudative AMD, have a marked impact on public health, the prevention and therapy of ophthalmic disorders remain of increasing concern. Exudative AMD is characterized by choroidal neovascularization (CNV) invading the subretinal space, ultimately enhancing exudation and hemorrhaging. The exudative AMD subtype corresponds to 10 to 15% of cases of macular degeneration; however, the occurrence of this subtype has been reported as the major cause of vision loss and blindness, with the occurrence of CNV being responsible for 80% of the cases with vision loss. In CNV increased expression of VEGF has been observed, stimulated by the overactivation of Wnt/β‑catenin signaling pathway. The stimulation of the Wnt/β‑catenin signaling pathway is responsible for the activation of several cellular mechanisms, simultaneously enhancing inflammation, oxidative stress and angiogenesis in numerous diseases, including ophthalmic disorders. Some studies have previously demonstrated the possible advantage of the use of curcumin for the inhibition of Wnt/β‑catenin signaling. In the present review article, the different mechanisms of curcumin are described concerning its effects on oxidative stress, inflammation and angiogenesis in exudative AMD, by interacting with Wnt/β‑catenin signaling.
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Affiliation(s)
- Alexandre Vallée
- Department of Epidemiology-Data-Biostatistics, Delegation of Clinical Research and Innovation (DRCI), Foch Hospital, 92150 Suresnes, France
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3
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Yu Y, Liu L, Hu LL, Yu LL, Li JP, Rao JA, Zhu LJ, Liang Q, Zhang RW, Bao HH, Cheng XS. Potential therapeutic target genes for systemic lupus erythematosus: a bioinformatics analysis. Bioengineered 2021; 12:2810-2819. [PMID: 34180358 PMCID: PMC8806421 DOI: 10.1080/21655979.2021.1939637] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs. However, the underlying etiology and mechanisms remain unclear. This study was performed to identify potential therapeutic targets for SLE using bioinformatics methods. First, 584 differentially expressed genes were identified based on the GSE61635 dataset. Tissue-specific analyses, enrichment analyses, and Protein–Protein interaction network were successively conducted. Furthermore, ELISA was performed to confirm the expression levels of key genes in the control and SLE blood samples. The findings revealed that tissue-specific expression of markers of the hematological system (25.5%, 28/110) varied significantly. CCL2, MMP9, and RSAD2 expression was markedly increased in the SLE samples compared with controls. In conclusion, the identified key genes (CCL2, MMP9, and RSAD2) may act as possible therapeutic targets for the treatment of SLE.
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Affiliation(s)
- Yun Yu
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Liang Liu
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Long-Long Hu
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Ling-Ling Yu
- Department of Rehabilitation, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Jun-Pei Li
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Jing-An Rao
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Ling-Juan Zhu
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Qian Liang
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Rong-Wei Zhang
- Department of Rheumatology, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Hui-Hui Bao
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Xiao-Shu Cheng
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
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4
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Ahsan B, Aldwaikat A, Aboud O, Ramadan A, Abu-Asab MS. Retinal and choroidal capillaries contribution to age-related macular degeneration (AMD) phenotypes in murine models of the disease. Ultrastruct Pathol 2020; 44:174-181. [PMID: 32079449 PMCID: PMC9930639 DOI: 10.1080/01913123.2020.1731039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Mouse models of age-related macular degeneration (AMD) such as Ccl2-/- and Ccl2-/-/Cx3cr1-/- have not yet been fully characterized ultrastructurally. Although we have previously shown extranuclear DNA (enDNA) leakage into the cytoplasm and damaged mitochondria in the retinal pigment epithelium (RPE) of these AMD mouse models, little is known about the state of their vascular capillaries of the retina and choroid. Our ultrastructural survey shows that the aberrations were not restricted to the RPE cells, but also extended to the vasculature of the retina and choroid. Their endothelial aberrations included cytoplasmic degeneration, pyknotic DNA, hypertrophic nuclei, and loss of fenestration in addition to duplication of basement membrane and loss of density in Bruch's membrane. Moreover, the state of the vasculature in the mutant mice models suggests that the capillaries could also be active contributors to the pathological findings seen in AMD. The goal of this study is to gain insights into the early events of AMD that may lead to a better understanding of AMD's pathogenesis, improve our preventative measures, and formulate designed therapeutic regimens that are tailored to target the initial pathological events.Abbreviations: AMD: age-related macular degeneration; BM: Bruch's membrane; DPC: degenerate pericyte; EN: endothelial nucleus; enDNA: extranuclear DNA; GCL: ganglion cell layer; HEN: hypertrophic endothelial nucleus; IPL: inner plexiform layer; NFL: nerve fiber layer; OPL: outer plexiform layer; RBC: red blood cell; RPE: retinal pigment epithelium; SNPs: Single nucleotide polymorphisms.
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Affiliation(s)
- Bisma Ahsan
- Section of Histopathology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ahmad Aldwaikat
- Division of Pulmonary and Critical Care and Sleep Medicine, Wayne State University School of Medicine, Detroit, MI, USA
| | - Orwa Aboud
- Neuro Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ali Ramadan
- Department of Pathology, Howard University Hospital, Washington, DC, USA
| | - Mones S. Abu-Asab
- Section of Histopathology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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Vallée A, Lecarpentier Y, Vallée R, Guillevin R, Vallée JN. Circadian Rhythms in Exudative Age-Related Macular Degeneration: The Key Role of the Canonical WNT/β-Catenin Pathway. Int J Mol Sci 2020; 21:ijms21030820. [PMID: 32012797 PMCID: PMC7037737 DOI: 10.3390/ijms21030820] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 02/07/2023] Open
Abstract
Age-related macular degeneration (AMD) is considered as the main worldwide cause of blindness in elderly adults. Exudative AMD type represents 10 to 15% of macular degeneration cases, but is the main cause of vision loss and blindness. Circadian rhythm changes are associated with aging and could further accelerate it. However, the link between circadian rhythms and exudative AMD is not fully understood. Some evidence suggests that dysregulation of circadian functions could be manifestations of diseases or could be risk factors for the development of disease in elderly adults. Biological rhythms are complex systems interacting with the environment and control several physiological pathways. Recent findings have shown that the dysregulation of circadian rhythms is correlated with exudative AMD. One of the main pathways involved in exudative AMD is the canonical WNT/β-catenin pathway. Circadian clocks have a main role in some tissues by driving the circadian expression of genes involved in physiological and metabolic functions. In exudative AMD, the increase of the canonical WNT/β-catenin pathway is enhanced by the dysregulation of circadian rhythms. Exudative AMD progression is associated with major metabolic reprogramming, initiated by aberrant WNT/β-catenin pathway, of aerobic glycolysis. This review focuses on the interest of circadian rhythm dysregulation in exudative AMD through the aberrant upregulation of the canonical WNT/β-catenin pathway.
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Affiliation(s)
- Alexandre Vallée
- DACTIM-MIS, Laboratory of Mathematics and Applications (LMA), UMR CNRS 7348, University of Poitiers, CHU de Poitiers, 86021 Poitiers, France
| | - Yves Lecarpentier
- Centre de Recherche Clinique, Grand Hôpital de l'Est Francilien (GHEF), 77100 Meaux, France
| | - Rodolphe Vallée
- University Hospital Group of Paris-Seine-Saint-Denis, APHP, University of Paris-13 Sorbonne Paris-Cité, 93000 Paris, France
| | - Rémy Guillevin
- DACTIM-MIS, Laboratory of Mathematics and Applications (LMA), UMR CNRS 7348, University of Poitiers, CHU de Poitiers, 86021 Poitiers, France
| | - Jean-Noël Vallée
- CHU Amiens Picardie, University of Picardie Jules Verne (UPJV), 80000 Amiens, France
- Laboratory of Mathematics and Applications (LMA), UMR CNRS 7348, University of Poitiers, 86021 Poitiers, France
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6
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Moore BA, Roux MJ, Sebbag L, Cooper A, Edwards SG, Leonard BC, Imai DM, Griffey S, Bower L, Clary D, Lloyd KCK, Hérault Y, Thomasy SM, Murphy CJ, Moshiri A. A Population Study of Common Ocular Abnormalities in C57BL/6N rd8 Mice. Invest Ophthalmol Vis Sci 2019; 59:2252-2261. [PMID: 29847629 PMCID: PMC5935295 DOI: 10.1167/iovs.17-23513] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose The purpose of this study was to quantify the frequency and severity of ocular abnormalities affecting wild-type C57BL/6N mice, the most common strain used worldwide for the creation of single-gene knockouts. Methods A total of 2773 animals (5546 eyes) were examined at one colony at UC Davis and in three more colonies at the Institut Clinique de la Souris in Strasbourg, France. Mice were examined at 15 to 16 weeks postnatal age by performing anterior segment biomicroscopy, posterior segment examination by indirect ophthalmoscopy, intraocular pressure measurement, and optical coherence tomography of anterior and posterior segment structures. Results Common ocular findings in the C57BL/6N strain included corneal deposits (3%), increased optical density of the anterior lens capsule (67%), punctate nuclear cataracts (98%), vitreous crystalline deposits (61%), hyaloid vascular remnant (6%), and retinal dysplasia attributed to the rd8 mutation (58%). Interestingly, retinal dysplasia was more common in male mice in all four breeding colonies evaluated in this study. The thickness of ocular tissues and compartments were measured by spectral-domain optical coherence tomography, including the central cornea, anterior chamber, vitreous, and retinal layers. Intraocular pressure was measured by rebound tonometry. Conclusions Ocular abnormalities are common in anterior and posterior segments of the C57BL/6N mouse, the most common background on which single-gene knockout mice have been made. It is important that vision scientists understand the extent and variability of ocular findings associated with this particular genetic background of mice.
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Affiliation(s)
- Bret A Moore
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Michel J Roux
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Lionel Sebbag
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Ann Cooper
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Sydney G Edwards
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Brian C Leonard
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Denise M Imai
- Comparative Pathology Laboratory, School of Veterinary Medicine, UC Davis, Davis, California, United States
| | - Stephen Griffey
- Comparative Pathology Laboratory, School of Veterinary Medicine, UC Davis, Davis, California, United States
| | - Lynette Bower
- Mouse Biology Program, University of California-Davis, Davis, California, United States
| | - Dave Clary
- Mouse Biology Program, University of California-Davis, Davis, California, United States
| | - K C Kent Lloyd
- Mouse Biology Program, University of California-Davis, Davis, California, United States.,Department of Surgery, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Yann Hérault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France.,CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), CNRS, INSERM, Université de Strasbourg, Illkirch, France
| | - Sara M Thomasy
- Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, UC Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Christopher J Murphy
- Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, UC Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Ala Moshiri
- Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
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7
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Vallée A, Lecarpentier Y, Guillevin R, Vallée JN. Aerobic Glycolysis Hypothesis Through WNT/Beta-Catenin Pathway in Exudative Age-Related Macular Degeneration. J Mol Neurosci 2017; 62:368-379. [PMID: 28689265 DOI: 10.1007/s12031-017-0947-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 06/28/2017] [Indexed: 12/18/2022]
Abstract
Exudative age-related macular degeneration (AMD) is characterized by molecular mechanisms responsible for the initiation of choroidal neovascularization (CNV). Inflammatory processes are associated with upregulation of the canonical WNT/beta-catenin pathway in exudative AMD. We focus this review on the link between WNT/beta-catenin pathway activation and neovascular progression in exudative AMD through activation of aerobic glycolysis for production of angiogenic factors. Increased WNT/beta-catenin pathway involves hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). WNT/beta-catenin pathway stimulates PI3K/Akt pathway and then HIF-1alpha which activates glycolytic enzymes: glucose transporter (Glut), pyruvate dehydrogenase kinase 1 (PDK1), lactate dehydrogenase A (LDH-A), and monocarboxylate lactate transporter (MCT-1). This phenomenon is called aerobic glycolysis or the Warburg effect. Consequently, phosphorylation of PDK-1 inhibits the pyruvate dehydrogenase complex (PDH). Thus, a large part of pyruvate cannot be converted into acetyl-CoA in mitochondria and only a part of acetyl-CoA can enter the tricarboxylic acid cycle. Cytosolic pyruvate is converted into lactate through the action of LDH-A. In exudative AMD, high level of cytosolic lactate is correlated with increase of VEGF expression, the angiogenic factor of CNV. Photoreceptors in retina cells can metabolize glucose through aerobic glycolysis to protect them against oxidative damage, as cancer cells do.
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Affiliation(s)
- Alexandre Vallée
- Experimental and Clinical Neurosciences Laboratory, INSERM U1084, University of Poitiers, Poitiers, France.
- Laboratoire de Mathématiques et Applications (LMA), UMR CNRS 7348, Université de Poitiers, 11 Boulevard Marie et Pierre Curie, Poitiers, France.
| | | | - Rémy Guillevin
- DACTIM, Laboratoire de Mathématiques et Applications, Université de Poitiers et CHU de Poitiers, UMR CNRS 7348, SP2MI Futuroscope, Chasseneuil-du-Poitou, France
| | - Jean-Noël Vallée
- Laboratoire de Mathématiques et Applications (LMA), UMR CNRS 7348, Université de Poitiers, 11 Boulevard Marie et Pierre Curie, Poitiers, France
- CHU Amiens Picardie, Université Picardie Jules Verne (UPJV), Amiens, France
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Polato F, Becerra SP. Pigment Epithelium-Derived Factor, a Protective Factor for Photoreceptors in Vivo. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:699-706. [PMID: 26427478 DOI: 10.1007/978-3-319-17121-0_93] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a natural protein of the retina with demonstrable neurotrophic properties, found in the interphotoreceptor matrix in intimate contact with photoreceptors. This review summarizes the effects of PEDF on photoreceptors in several animal models of retinal degeneration.
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Affiliation(s)
- Federica Polato
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, NIH-NEI BG.6. Room 134. 6 Center Drive MSC 0608, 20892-0608, Bethesda, MD, USA.
| | - S Patricia Becerra
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, NIH-NEI BG.6. Room 134. 6 Center Drive MSC 0608, 20892-0608, Bethesda, MD, USA.
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9
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Wang Y, Hanus JW, Abu-Asab MS, Shen D, Ogilvy A, Ou J, Chu XK, Shi G, Li W, Wang S, Chan CC. NLRP3 Upregulation in Retinal Pigment Epithelium in Age-Related Macular Degeneration. Int J Mol Sci 2016; 17:E73. [PMID: 26760997 PMCID: PMC4730317 DOI: 10.3390/ijms17010073] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 12/29/2015] [Accepted: 12/30/2015] [Indexed: 01/03/2023] Open
Abstract
Inflammation and oxidative stress are involved in age-related macular degeneration (AMD) and possibly associated with an activation of neuronal apoptosis inhibitor protein/class II transcription activator of the Major Histocompatibility Complex (MHC)/heterokaryon incompatibility/telomerase-associated protein 1, leucine-rich repeat or nucleotide-binding domain, leucine-rich repeat-containing family, and pyrin domain-containing 3 (NLRP3) inflammasome. In the present study, we used a translational approach to address this hypothesis. In patients with AMD, we observed increased mRNA levels of NLRP3, pro-interleukin-1 beta (IL-1β) and pro-IL-18 in AMD lesions of the retinal pigment epithelium (RPE) and photoreceptor. In vitro, a similar increase was evoked by oxidative stress or lipopolysaccharide (LPS) stimulation in the adult retinal pigment epithelium (ARPE-19) cell line, and the increase was reduced in siRNA transfected cells to knockdown NLRP3. Ultrastructural studies of ARPE-19 cells showed a swelling of the cytoplasm, mitochondrial damage, and occurrence of autophagosome-like structures. NLRP3 positive dots were detected within autophagosome-like structures or in the extracellular space. Next, we used a mouse model of AMD, Ccl2/Cx3cr1 double knockout on rd8 background (DKO rd8) to ascertain the in vivo relevance. Ultrastructural studies of the RPE of these mice showed damaged mitochondria, autophagosome-like structures, and cytoplasmic vacuoles, which are reminiscent of the pathology seen in stressed ARPE-19 cells. The data suggest that the NLRP3 inflammasome may contribute in AMD pathogenesis.
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Affiliation(s)
- Yujuan Wang
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
| | - Jakub W Hanus
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA.
| | - Mones S Abu-Asab
- Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Defen Shen
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Alexander Ogilvy
- Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jingxing Ou
- Unit on Retinal Neurophysiology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Xi K Chu
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Guangpu Shi
- Experimental Immunology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Wei Li
- Unit on Retinal Neurophysiology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA.
| | - Chi-Chao Chan
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
- Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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10
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Markand S, Saul A, Tawfik A, Cui X, Rozen R, Smith SB. Mthfr as a modifier of the retinal phenotype of Crb1(rd8/rd8) mice. Exp Eye Res 2015; 145:164-172. [PMID: 26646559 DOI: 10.1016/j.exer.2015.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 10/21/2015] [Accepted: 11/20/2015] [Indexed: 10/22/2022]
Abstract
Mutations in crumb homologue 1 (CRB1) in humans are associated with Leber's congenital amaurosis (LCA) and retinitis pigmentosa (RP). There is no clear genotype-phenotype correlation for human CRB1 mutations in RP and LCA. The high variability in clinical features observed in CRB1 mutations suggests that environmental factors or genetic modifiers influence severity of CRB1 related retinopathies. Retinal degeneration 8 (rd8) is a spontaneous mutation in the Crb1 gene (Crb1(rdr/rd8)). Crb1(rdr/rd8) mice present with focal disruption in the outer retina manifesting as white spots on fundus examination. Mild retinal dysfunction with decreased b-wave amplitude has been reported in Crb1(rdr/rd8) mice at 18 months. Methylene tetrahydrofolate reductase (MTHFR) is a crucial enzyme of homocysteine metabolism. MTHFR mutations are prevalent in humans and are linked to a broad spectrum of disorders including cardiovascular and neurodegenerative diseases. We recently reported the retinal phenotype in Mthfr-deficient (Mthfr(+/-)) heterozygous mice. At 24 weeks the mice showed decreased RGC function, thinner nerve fiber layer, focal areas of vascular leakage and 20% fewer cells in the ganglion cell layer (GCL). Considering the variability in CRB1-related retinopathies and the high occurrence of human MTHFR mutations we evaluated whether Mthfr deficiency influences rd8 retinal phenotype. Mthfr heterozygous mice with rd8 mutations (Mthfr(+/-)(rd8/rd8)) and Crb(rd8/rd8) mice (Mthfr(+/+rd8/rd8)) mice were subjected to comprehensive retinal evaluation using ERG, fundoscopy, fluorescein angiography (FA), morphometric and retinal flat mount immunostaining analyses of isolectin-B4 at 8-54 wks. Assessment of retinal function revealed a significant decrease in the a-, b- and c-wave amplitudes in Mthfr(+/-)(rd8/rd8) mice at 52 wks. Fundoscopic evaluation demonstrated the presence of signature rd8 spots in Mthfr(+/+rd8/rd8) mice and an increase in the extent of these rd8 spots in Mthfr(+/-)(rd8/rd8) mice at 24 weeks and beyond. FA revealed marked vascular leakage, ischemia and vascular tortuosity in Mthfr(+/-)(rd8/rd8) mice at 24 and 52 weeks. Retinal dysplasia was observed in ∼14-33% Mthfr(+/-)(rd8/rd8) mice by morphometric analysis. This was accompanied by a ∼20% reduction in cells of the GCL of Mthfr(+/-)(rd8/rd8) mice at 24 and 52 weeks. Retinal flat mount immunostaining with isolectin-B4 showed neovascularization and loss of blood vessel integrity in Mthfr(+/-)(rd8/rd8) mice in contrast to mild vasculopathy in Mthfr(+/+rd8/rd8) mice. Taken together, our data support an earlier onset and worsened retinal phenotype when Mthfr and rd8 mutations coexist. Our study sets the stage for future studies to investigate the role of MTHFR deficiency in human CRB1 retinopathies.
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Affiliation(s)
- Shanu Markand
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA
| | - Alan Saul
- The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Amany Tawfik
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA
| | - Xuezhi Cui
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA
| | - Rima Rozen
- Departments of Pediatrics and Human Genetics, McGill University, Montreal, Canada
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
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11
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Pak JS, Lee EJ, Craft CM. The retinal phenotype of Grk1-/- is compromised by a Crb1 rd8 mutation. Mol Vis 2015; 21:1281-94. [PMID: 26664249 PMCID: PMC4663191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 11/25/2015] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Well-established laboratory mouse lines are important in creating genetically engineered knockout mouse models; however, these routinely used inbred strains are prone to spontaneous and deleterious mutations. One of these strains, the commonly used C57BL/6N (B6N), was discovered to carry a point mutation in the Crumbs homolog 1 (Crb1(rd8) ) gene, which codes for a developmental protein involved in tight junction formation at the outer limiting membrane (OLM). This mutation disrupts photoreceptor polarity and leads to retinal degeneration. It was hypothesized that the G-protein receptor kinase 1 knockouts (Grk1(-/-) ), which were based on the B6N strain, would exhibit abnormal morphological phenotypes in their offspring not related to GRK1's major phosphorylation function. The hypothesis was tested by examining Grk1(-/-) with or without the Crb1(rd8) mutation. METHODS The mice strains tested were C57BL/6J (B6J), B6N, and Grk1(-/-) on either a B6J (Grk1(-/-) (;B6J)) or B6N background (Grk1(-/-) (;B6N)) and were verified with PCR genotype analysis for Grk1(-/-) and Crb (rd8) . The mice were bred and raised in complete darkness until 1 or 3 months of age and then exposed to 1,000 lux light for 24 h, followed by processing for immunohistochemistry (IHC) analysis on the retinal structure to investigate the morphological effects of light exposure. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was performed to detect photoreceptor apoptosis. RESULTS The microanatomy of the retinal sections revealed disorganization of the outer nuclear layer (ONL) in the B6N and Grk1(-/-) (;B6N) mice and a significant decrease in the thickness of the ONL in the 3-month-old Grk1(-/-) (;B6N) mice. The adherens-junction-associated protein, Zona occludens-1 (ZO-1), formed a continuous line at the OLM in the 1- and 3-month-old control B6J and Grk1(-/-) (;B6J) mice. In contrast, the B6N and Grk1(-/-) (;B6N) retinas showed discontinuous and fragmented staining for ZO-1 at the OLM at both ages. After the mice were exposed to light, TUNEL analysis showed a significant increase in photoreceptor cell death in the Grk1(-/-) (;B6J) and Grk1(-/-) (;B6N) retinas versus either the B6J or B6N retinas at 1 and 3 months of age and a small significant difference between the Grk1(-/-) (;B6J) and Grk1(-/-) (;B6N) retinas at 1 month. In addition, glial fibrillary acidic protein (GFAP) expression was enhanced in the Grk1(-/-) (;B6J) and Grk1(-/-) (;B6N) retinas at 1 and 3 months. Occasional sprouting processes of rod bipolar cells were detected in the B6N and Grk1(-/-) (;B6N) retinas, but sprouting was not detected in the B6J or Grk1(-/-) (;B6J) retinas at either age. CONCLUSIONS The B6N strain background exhibited abnormal phenotypes in the Grk1(-/-) (;B6N) retina. This study demonstrates that the B6N background can influence the phenotype of a genetic mouse knockout and introduces potential visual functional consequences of the Crb1 mutation.
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Affiliation(s)
- Joseph S. Pak
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Departments of Ophthalmology and Cell & Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
| | - Eun-Jin Lee
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Departments of Ophthalmology and Cell & Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, CA,Department of Biomedical Engineering, University of Southern California Viterbi School of Engineering, CA
| | - Cheryl Mae Craft
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Departments of Ophthalmology and Cell & Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
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12
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Hanus J, Anderson C, Wang S. RPE necroptosis in response to oxidative stress and in AMD. Ageing Res Rev 2015; 24:286-98. [PMID: 26369358 PMCID: PMC4661094 DOI: 10.1016/j.arr.2015.09.002] [Citation(s) in RCA: 185] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/19/2015] [Accepted: 09/09/2015] [Indexed: 12/19/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly. The underlying mechanism of non-neovascular AMD (dry AMD), also named geographic atrophy (GA) remains unclear and the mechanism of retinal pigment epithelial (RPE) cell death in AMD is controversial. We review the history and recent progress in understanding the mechanism of RPE cell death induced by oxidative stress, in AMD mouse models, and in AMD patients. Due to the limitation of toolsets to distinguish between apoptosis and necroptosis (or necrosis), most previous research concludes that apoptosis is a major mechanism for RPE cell death in response to oxidative stress and in AMD. Recent studies suggest necroptosis as a major mechanism of RPE cell death in response to oxidative stress. Moreover, ultrastructural and histopathological studies support necrosis as major mechanism of RPE cells death in AMD. In this review, we discuss the mechanism of RPE cell death in response to oxidative stress, in AMD mouse models, and in human AMD patients. Based on the literature, we hypothesize that necroptosis is a major mechanism for RPE cell death in response to oxidative stress and in AMD.
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Affiliation(s)
- Jakub Hanus
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Chastain Anderson
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA; Department of Ophthalmology, Tulane University, New Orleans, LA 70118, USA.
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13
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Tuo J, Wang Y, Cheng R, Li Y, Chen M, Qiu F, Qian H, Shen D, Penalva R, Xu H, Ma JX, Chan CC. Wnt signaling in age-related macular degeneration: human macular tissue and mouse model. J Transl Med 2015; 13:330. [PMID: 26476672 PMCID: PMC4609061 DOI: 10.1186/s12967-015-0683-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 09/29/2015] [Indexed: 01/02/2023] Open
Abstract
Background The wingless-type MMTV integration site (Wnt) signaling is a group of signal transduction pathways. In canonical Wnt pathway, Wnt ligands bind to low-density lipoprotein receptor-related protein 5 or 6 (LRP5 or LRP6), resulting in phosphorylation and activation of the receptor. We hypothesize that canonical Wnt pathway plays a role in the retinal lesion of age-related macular degeneration (AMD), a leading cause of irreversible central visual loss in elderly. Methods We examined LRP6 phosphorylation and Wnt signaling cascade in human retinal sections and plasma kallistatin, an endogenous inhibitor of the Wnt pathway in AMD patients and non-AMD subjects. We also used the Ccl2−/−/Cx3cr1−/−/rd8 and Ccl2−/−/Cx3cr1gfp/gfp mouse models with AMD-like retinal degeneration to further explore the involvement of Wnt signaling activation in the retinal lesions in those models and to preclinically evaluate the role of Wnt signaling suppression as a potential therapeutic option for AMD. Results We found higher levels of LRP6 (a key Wnt signaling receptor) protein phosphorylation and transcripts of the Wnt pathway-targeted genes, as well as higher beta-catenin protein in AMD macula compared to controls. Kallistatin was decreased in the plasma of AMD patients. Retinal non-phosphorylated-β-catenin and phosphorylated-LRP6 were higher in Ccl2−/−/Cx3cr1−/−/rd8 mice than that in wild type. Intravitreal administration of an anti-LRP6 antibody slowed the progression of retinal lesions in Ccl2−/−/Cx3cr1−/−/rd8 and Ccl2−/−/Cx3cr1gfp/gfp mice. Electroretinography of treated eyes exhibited larger amplitudes compared to controls in both mouse models. A2E, a retinoid byproduct associated with AMD was lower in the treated eyes of Ccl2−/−/Cx3cr1−/−/rd8 mice. Anti-LRP6 also suppressed the expression of Tnf-α and Icam-1 in Ccl2−/−/Cx3cr1−/−/rd8 retinas. Conclusions Wnt signaling may be disturbed in AMD patients, which could contribute to the retinal inflammation and increased A2E levels found in AMD. Aberrant activation of canonical Wnt signaling might also contribute to the focal retinal degenerative lesions of mouse models with Ccl2 and Cx3cr1 deficiency, and intravitreal administration of anti-LRP6 antibody could be beneficial by deactivating the canonical Wnt pathway. Electronic supplementary material The online version of this article (doi:10.1186/s12967-015-0683-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jingsheng Tuo
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
| | - Yujuan Wang
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
| | - Rui Cheng
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Mei Chen
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.
| | - Fangfang Qiu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Defen Shen
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
| | - Rosana Penalva
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.
| | - Heping Xu
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Chi-Chao Chan
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm. 10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA.
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14
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Saadane A, Mast N, Charvet CD, Omarova S, Zheng W, Huang SS, Kern TS, Peachey NS, Pikuleva IA. Retinal and nonocular abnormalities in Cyp27a1(-/-)Cyp46a1(-/-) mice with dysfunctional metabolism of cholesterol. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2403-19. [PMID: 25065682 DOI: 10.1016/j.ajpath.2014.05.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/21/2014] [Accepted: 05/29/2014] [Indexed: 01/08/2023]
Abstract
Cholesterol elimination from nonhepatic cells involves metabolism to side-chain oxysterols, which serve as transport forms of cholesterol and bioactive molecules modulating a variety of cellular processes. Cholesterol metabolism is tissue specific, and its significance has not yet been established for the retina, where cytochromes P450 (CYP27A1 and CYP46A1) are the major cholesterol-metabolizing enzymes. We generated Cyp27a1(-/-)Cyp46a1(-/-) mice, which were lean and had normal serum cholesterol and glucose levels. These animals, however, had changes in the retinal vasculature, retina, and several nonocular organs (lungs, liver, and spleen). Changes in the retinal vasculature included structural abnormalities (retinal-choroidal anastomoses, arteriovenous shunts, increased permeability, dilation, nonperfusion, and capillary degeneration) and cholesterol deposition and oxidation in the vascular wall, which also exhibited increased adhesion of leukocytes and activation of the complement pathway. Changes in the retina included increased content of cholesterol and its metabolite, cholestanol, which were focally deposited at the apical and basal sides of the retinal pigment epithelium. Retinal macrophages of Cyp27a1(-/-)Cyp46a1(-/-) mice were activated, and oxidative stress was noted in their photoreceptor inner segments. Our findings demonstrate the importance of retinal cholesterol metabolism for maintenance of the normal retina, and suggest new targets for diseases affecting the retinal vasculature.
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Affiliation(s)
- Aicha Saadane
- Department of Ophthalmology and Visual Sciences, Cleveland, Ohio
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Cleveland, Ohio
| | - Casey D Charvet
- Department of Ophthalmology and Visual Sciences, Cleveland, Ohio
| | - Saida Omarova
- Department of Ophthalmology and Visual Sciences, Cleveland, Ohio
| | - Wenchao Zheng
- Department of Ophthalmology and Visual Sciences, Cleveland, Ohio
| | - Suber S Huang
- Department of Ophthalmology and Visual Sciences, Cleveland, Ohio; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Timothy S Kern
- Department of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio; Cleveland VA Medical Center, Cleveland, Ohio; Department of Medicine, University Hospitals, Cleveland, Ohio
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Cleveland, Ohio.
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15
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Ogilvy AJ, Shen D, Wang Y, Chan CC, Abu-Asab MS. Implications of DNA leakage in eyes of mutant mice. Ultrastruct Pathol 2014; 38:335-43. [PMID: 24963552 DOI: 10.3109/01913123.2014.927406] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Extranuclear DNA (enDNA) is not well studied ultrastructurally in the retinal pigment epithelium (RPE). We analyzed the retina and vastus medialis muscle of four mouse strains that are related to focal retinal degeneration by transmission electron microscopy (TEM) and EM immunolabeling. Evaluation of enDNA would imply the involvements of enDNA is either limited to the affected tissue or generalized in the whole body. Ultrastructural analysis and EM immunolabeling revealed that enDNA was present in the RPE cells but not in the muscle. These data suggest that enDNA could be unique to unhealthy RPE and a potential biomarker for cellular abnormality.
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Affiliation(s)
- Alexander J Ogilvy
- Laboratory of Immunology, National Eye Institute , Bethesda, MA , USA and
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16
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Wang Y, Abu-Asab MS, Yu CR, Tang Z, Shen D, Tuo J, Li X, Chan CC. Platelet-derived growth factor (PDGF)-C inhibits neuroretinal apoptosis in a murine model of focal retinal degeneration. J Transl Med 2014; 94:674-82. [PMID: 24709779 PMCID: PMC4039574 DOI: 10.1038/labinvest.2014.60] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 03/06/2014] [Accepted: 03/10/2014] [Indexed: 01/06/2023] Open
Abstract
Platelet-derived growth factor (PDGF)-C is a member of the PDGF family and is critical for neuronal survival in the central nervous system. We studied the possible survival and antiapoptotic effects of PDGF-C on focal retinal lesions in Ccl2(-/-)/Cx3cr1(-/-) on C57BL/6N [Crb1(rd8)] (DKO rd8) background mice, a model for progressive and focal retinal degeneration. We found no difference in transcript and protein expression of PDGF-C in the retina between DKO rd8 mice and wild type (WT, C57BL/6N). Recombinant PDGF-CC protein (500 ng/eye) was injected intravitreally into the right eye of DKO rd8 mice with phosphate-buffered saline as controls into the left eye. The retinal effects of PDGF-C were assessed by fundoscopy, ocular histopathology, A2E levels, apoptotic molecule analysis, and direct flat mount retinal vascular labeling. We found that the PDGF-CC-treated eyes showed slower progression or attenuation of the focal retinal lesions, lesser photoreceptor and retinal pigment epithelial degeneration resulting in better-preserved photoreceptor structure. Lower expression of apoptotic molecules was detected in the PDGF-CC-treated eyes than in controls. In addition, no retinal neovascularization was observed after PDGF-CC treatment. Our results demonstrate that PDGF-C potently ameliorates photoreceptor degeneration via the suppression of apoptotic pathways without inducing retinal angiogenesis. The protective effects of PDGF-C suggest a novel alternative approach for potential age-related retinal degeneration treatment.
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Affiliation(s)
- Yujuan Wang
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060, P.R. China
| | - Mones S. Abu-Asab
- Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cheng-Rong Yu
- Molecular Immunology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhongshu Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060, P.R. China
| | - Defen Shen
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jingsheng Tuo
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xuri Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060, P.R. China
| | - Chi-Chao Chan
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA,Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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17
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Ardeljan D, Wang Y, Park S, Shen D, Chu XK, Yu CR, Abu-Asab M, Tuo J, Eberhart CG, Olsen TW, Mullins RF, White G, Wadsworth S, Scaria A, Chan CC. Interleukin-17 retinotoxicity is prevented by gene transfer of a soluble interleukin-17 receptor acting as a cytokine blocker: implications for age-related macular degeneration. PLoS One 2014; 9:e95900. [PMID: 24780906 PMCID: PMC4004582 DOI: 10.1371/journal.pone.0095900] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/31/2014] [Indexed: 01/11/2023] Open
Abstract
Age-related macular degeneration (AMD) is a common yet complex retinal degeneration that causes irreversible central blindness in the elderly. Pathology is widely believed to follow loss of retinal pigment epithelium (RPE) and photoreceptor degeneration. Here we report aberrant expression of interleukin-17A (IL17A) and the receptor IL17RC in the macula of AMD patients. In vitro, IL17A induces RPE cell death characterized by the accumulation of cytoplasmic lipids and autophagosomes with subsequent activation of pro-apoptotic Caspase-3 and Caspase-9. This pathology is reduced by siRNA knockdown of IL17RC. IL17-dependent retinal degeneration in a mouse model of focal retinal degeneration can be prevented by gene therapy with adeno-associated virus vector encoding soluble IL17 receptor. This intervention rescues RPE and photoreceptors in a MAPK-dependent process. The IL17 pathway plays a key role in RPE and photoreceptor degeneration and could hold therapeutic potential in AMD.
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Affiliation(s)
- Daniel Ardeljan
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Yujuan Wang
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Stanley Park
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Defen Shen
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Xi Kathy Chu
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Cheng-Rong Yu
- Molecular Immunology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Mones Abu-Asab
- Histology Core, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jingsheng Tuo
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Charles G. Eberhart
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Timothy W. Olsen
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States of America
| | - Robert F. Mullins
- Department of Ophthalmology and Visual Sciences, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Gary White
- Genzyme Corporation, Framingham, Massachusetts, United States of America
| | - Sam Wadsworth
- Genzyme Corporation, Framingham, Massachusetts, United States of America
| | - Abraham Scaria
- Genzyme Corporation, Framingham, Massachusetts, United States of America
| | - Chi-Chao Chan
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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18
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Low BE, Krebs MP, Joung JK, Tsai SQ, Nishina PM, Wiles MV. Correction of the Crb1rd8 allele and retinal phenotype in C57BL/6N mice via TALEN-mediated homology-directed repair. Invest Ophthalmol Vis Sci 2014; 55:387-95. [PMID: 24346171 DOI: 10.1167/iovs.13-13278] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We directly corrected the mouse Crb1(rd8) gene mutation, which is present in many inbred laboratory strains derived from C57BL/6N and complicates genetic studies of retinal disease in mice. METHODS Fertilized C57BL/6NJ oocytes were coinjected with mRNAs encoding a transcription activator-like effector nuclease (TALEN) targeting the Crb1(rd8) allele plus single-stranded oligonucleotides to correct the allele. The oligonucleotides included additional nucleotide changes to distinguish the corrected allele (Crb1(em1Mvw)) from wild-type Crb1 and to minimize TALEN recutting. Oligonucleotide length, concentration of injected oligonucleotides and TALEN mRNAs were varied to optimize homology-directed repair of the locus. Following microinjection, embryos were carried to term in pseudopregnant females. Correction efficiency was assessed by PCR analysis of the Crb1(em1Mvw) allele. Phenotypic correction was demonstrated by fundus imaging and optical coherence tomography of live mice, and by confocal fluorescence microscopy of retinal flat mounts. RESULTS Under optimal conditions, homology-directed repair was observed in 27% (8/30) of live-born animals and showed minimal illegitimate recombination of donor DNA. However, extensive founder mosaicism was evident, emphasizing the need to analyze offspring of founder animals. Unlike C57BL/6NJ mice, which exhibited external limiting membrane fragmentation and regional retinal dysplasia, heterozygous Crb1(em1Mvw)/Crb1(rd8) mice showed a normal retinal phenotype. CONCLUSIONS The C57BL/6NJ-Crb1(rd8) mutation and its associated retinal phenotypes were corrected efficiently by TALEN-mediated homology-directed repair. The C57BL/6NJ-Crb1(em1Mvw) mice generated by this strategy will enhance ocular phenotyping efforts based on the C57BL/6N background, such as those implemented by the International Mouse Phenotyping Consortium (IMPC) project.
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19
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Promsote W, Veeranan-Karmegam R, Ananth S, Shen D, Chan CC, Lambert NA, Ganapathy V, Martin PM. L-2-oxothiazolidine-4-carboxylic acid attenuates oxidative stress and inflammation in retinal pigment epithelium. Mol Vis 2014; 20:73-88. [PMID: 24426777 PMCID: PMC3888500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 01/03/2014] [Indexed: 11/21/2022] Open
Abstract
PURPOSE Oxidant- and inflammation-induced damage to retinal pigment epithelial (RPE) cells is central to the pathogenesis of age-related macular degeneration (AMD). Thus, developing novel strategies to protect these cells is important. We reported previously on the robust antioxidant and therefore cell-protective effects of the cysteine pro-drug L-2-oxothiazolidine-4-carboxylic acid (OTC) in cultured human RPE cells. New reports citing a novel anti-inflammatory role for OTC in addition to the known glutathione-stimulating and antioxidant properties emerged recently; however, this role has not been evaluated in RPE cells or in intact retina. Given the crucial causative roles of oxidative stress and inflammation in AMD pathogenesis, knowing whether OTC might exhibit a similar benefit in this cell and tissue type has high clinical relevance; thus, we evaluated OTC in the present study. METHODS ARPE-19 and primary RPE cells isolated from wild-type, Gpr109a(-/-) , or Slc5a8(-/-) mouse eyes were exposed to TNF-α in the presence or absence of OTC, followed by analysis of IL-6 and Ccl2 expression with real-time quantitative polymerase chain reaction or enzyme-linked immunosorbent assay. Cellular and molecular markers of inflammation and oxidative stress (i.e., IL-1β, TGF-β, ABCG1, ABCA1, reduced glutathione, and dihydroethidium) were evaluated in Ccl2(-/-)/Cx3cr1(-/-) double knockout mice on rd8 background (DKO rd8) treated with OTC (10 mg/ml) in drinking water for a period of 5 months. RESULTS OTC treatment significantly inhibited the expression and secretion of IL-6 and Ccl2 in TNF-α-stimulated ARPE-19 cells. Studies conducted using DKO rd8 animals treated with OTC in drinking water confirmed these findings. Cellular and molecular markers of inflammation were significantly suppressed in the retinas of the OTC-treated DKO rd8 animals. Subsequent in vitro and in vivo studies of the possible mechanism(s) to explain these actions revealed that although OTC is an agonist of the anti-inflammatory G-protein coupled receptor GPR109A and a transportable substrate of the sodium-coupled monocarboxylate transporter SMCT1 (SLC5A8), these properties may play a role but do not explain entirely the anti-inflammatory effects this compound elicits in cultured RPE cells and the intact mouse retina. CONCLUSIONS This study represents, to our knowledge, the first report of the suppressive effects of OTC on inflammation in cultured RPE cells and on inflammation and oxidative stress in the retina in vivo.
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Affiliation(s)
- Wanwisa Promsote
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, GA
| | | | - Sudha Ananth
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, GA
| | - Defen Shen
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Chi-Chao Chan
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Nevin A. Lambert
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, GA
| | - Vadivel Ganapathy
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, GA,James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA
| | - Pamela M. Martin
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, GA,Department of Ophthalmology, and the Georgia Regents University, Augusta, GA,James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA
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20
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Pigment epithelium-derived factor reduces apoptosis and pro-inflammatory cytokine gene expression in a murine model of focal retinal degeneration. ASN Neuro 2013; 5:e00126. [PMID: 24160756 PMCID: PMC3840469 DOI: 10.1042/an20130028] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
AMD (age-related macular degeneration) is a neurodegenerative disease causing irreversible central blindness in the elderly. Apoptosis and inflammation play important roles in AMD pathogenesis. PEDF (pigment epithelium-derived factor) is a potent neurotrophic and anti-inflammatory glycoprotein that protects the retinal neurons and photoreceptors against cell death caused by pathological insults. We studied the effects of PEDF on focal retinal lesions in DKO rd8 (Ccl2−/−/Cx3cr1−/− on C57BL/6N [Crb1rd8]) mice, a model for progressive, focal rd (retinal degeneration). First, we found a significant decrease in PEDF transcript expression in DKO rd8 mouse retina and RPE (retinal pigment epithelium) than WT (wild-type, C57BL/6N). Next, cultured DKO rd8 RPE cells secreted lower levels of PEDF protein in the media than WT. Then the right eyes of DKO rd8 mice were injected intravitreously with recombinant human PEDF protein (1 μg), followed by a subconjunctival injection of PEDF (3 μg) 4 weeks later. The untreated left eyes served as controls. The effect of PEDF was assessed by fundoscopy, ocular histopathology and A2E {[2,6-dimethyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E,3E,5E,7E-octatetra-enyl]-1-(2-hydroxyethyl)-4-[4-methyl-6(2,6,6-trimethyl-1-cyclohexen-1-yl) 1E,3E,5E,7E-hexatrienyl]-pyridinium} levels, as well as apoptotic and inflammatory molecules. The PEDF-treated eyes showed slower progression or attenuation of the focal retinal lesions, fewer and/or smaller photoreceptor and RPE degeneration, and significantly lower A2E, relative to the untreated eyes. In addition, lower expression of apoptotic and inflammatory molecules were detected in the PEDF-treated than untreated eyes. Our results establish that PEDF potently stabilizes photoreceptor degeneration via suppression of both apoptotic and inflammatory pathways. The multiple beneficial effects of PEDF represent a novel approach for potential AMD treatment. Apoptosis and inflammation play important roles in age-related macular degeneration. As a potent neurotrophic and anti-inflammatory glycoprotein, PEDF potently stabilizes photoreceptor degeneration via suppression of apoptotic and inflammatory pathways in a mouse model of progressive, focal rd.
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Zhang J, Tuo J, Cao X, Shen D, Li W, Chan CC. Early degeneration of photoreceptor synapse in Ccl2/Cx3cr1-deficient mice on Crb1(rd8) background. Synapse 2013; 67:515-31. [PMID: 23592324 DOI: 10.1002/syn.21674] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 04/03/2013] [Indexed: 12/13/2022]
Abstract
Photoreceptor ribbon synapse releases glutamate to postsynaptic targets. The synaptic ribbon may play multiple roles in ribbon synapse development, synaptic vesicle recycling, and synaptic transmission. Age-related macular degeneration (AMD) patients appear to have fewer or no detectable synaptic ribbons as well as abnormal swelling in the photoreceptor terminals in the macula. However, reports on changes of photoreceptor synapses in AMD are scarce and photoreceptor type and quantity affected in early AMD is still unclear. Here, we employed multiple anatomical techniques to investigate these questions in Ccl2⁻/⁻/Cx3cr1⁻/⁻ mouse on Crb1(rd8) background (DKO rd8) at one month of age. We found that approximately 17% of photoreceptors over the focal lesion were lost. Immunostaining for synapse-associated proteins (CtBP2, synaptophysin, and vesicular glutamate transporter 1) showed significantly reduced expression and ectopic localization. Cone opsins demonstrated dramatic reduction in expression (S-opsins) and extensive mislocalization (M-opsins). Quantitative ultrastructural analysis confirmed a significant decrease in the number of cone terminals and nuclei, numerous vacuoles in remaining cone terminals, reduction in the number of synaptic ribbons in photoreceptor terminals, and ectopic rod ribbon synapses. In addition, glutamate receptor immunoreactivity on aberrant sprouting of rod bipolar cells and horizontal cells were identified at the ectopic synapses. These results indicate that synaptic alterations occur at the early stages of disease and cones are likely more susceptible to damage caused by DKO rd8 mutation. They provide a new insight into potential mechanism of vision function lost due to synaptic degeneration before cell death in the early stages of AMD.
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Affiliation(s)
- Jun Zhang
- Histology Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Popp N, Chu XK, Shen D, Tuo J, Chan CC. Evaluating Potential Therapies in a Mouse Model of Focal Retinal Degeneration with Age-related Macular Degeneration (AMD)-Like Lesions. ACTA ACUST UNITED AC 2013; 4:1000296. [PMID: 24432192 PMCID: PMC3890246 DOI: 10.4172/2155-9570.1000296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although the mouse has no macula leutea, its neuroretina and retinal pigment epithelium (RPE) can develop lesions mimicking certain features of age-related macular degeneration (AMD). Differences between the Ccl2 and Cx3cr1 double deficient mouse on Crb1rd8(rd8) background (DKOrd8) and the Crb1rd8 mouse in photoreceptor and RPE pathology, as well as ocularA2E contents and immune responses, show that DKOrd8 recapitulates some human AMD-like features in addition to rd8 retinal dystrophy/degeneration. Different therapeutic interventions have been demonstrated to be effective on the AMD-like features of DKOrd8 mice. The use of the DKOrd8 model and C57BL/6N (wild type, WT) mice as group controls (4 groups) to test treatments such as high omega-3 polyunsaturated fatty acid (n-3) diet has, for example, shown the beneficial effect of n-3 on AMD-like lesions by anti-inflammatory action of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). The use of self-control in the DKOrd8 mouse by treating one eye and using the contralateral eye as the control for the same mouse allows for appropriate interventional experiments and evaluates various novel therapeutic agents. Three examples will be briefly presented and discussed: (1) tumor necrosis factor-inducible gene 6 recombinant protein (TSG-6) arrests the AMD-like lesions via modulation of ocular immunological gene expression, e.g., Il-17a; (2) adeno-associated virus encoding sIL-17R (AAV2.sIL17R) stabilizes the AMD-like lesions; and (3) pigment epithelium-derived factor (PEDF) ameliorates the AMD-lesions by its anti-inflammatory, anti-apoptotic and neuroprotective roles. Therefore, the DKOrd8 mouse model can be useful and appropriate for therapeutic compound screening in the management of human AMD.
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Affiliation(s)
- Nicholas Popp
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Dr., 10/10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA
| | - Xi K Chu
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Dr., 10/10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA
| | - Defen Shen
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Dr., 10/10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA
| | - Jingsheng Tuo
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Dr., 10/10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA
| | - Chi-Chao Chan
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, 10 Center Dr., 10/10N103, NIH/NEI, Bethesda, MD, 20892-1857, USA
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