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Occelli LM, Tran NM, Chen S, Petersen-Jones SM. Cat LCA-CRX Model, Homozygous for an Antimorphic Mutation Has a Unique Phenotype. Transl Vis Sci Technol 2023; 12:15. [PMID: 37351895 PMCID: PMC10292669 DOI: 10.1167/tvst.12.6.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 05/15/2023] [Indexed: 06/24/2023] Open
Abstract
Purpose Mutations in the CRX transcription factor are associated with dominant retinopathies often with more severe macular changes. The CRX-mutant cat (Rdy-A182d2) is the only animal model with the equivalent of the critical retinal region for high-acuity vision, the macula. Heterozygous cats (CRXRdy/+) have a severe phenotype modeling Leber congenital amaurosis. This study reports the distinct ocular phenotype of homozygous cats (CRXRdy/Rdy). Methods Gene expression changes were assessed at both mRNA and protein levels. Changes in globe morphology and retinal structure were analyzed. Results CRXRdy/Rdy cats had high levels of mutant CRX mRNA and protein. The expression of photoreceptor target genes was severely impaired although there were variable effects on the expression of other transcription factors. The photoreceptor cells remained immature and failed to elaborate outer segments consistent with the lack of retinal function. The retinal layers displayed a progressive remodeling with cell loss but maintained overall retinal thickness due to gliosis. Rapid photoreceptor loss largely occurred in the macula-equivalent retinal region. The homozygous cats developed markedly increased ocular globe length. Conclusions The phenotype of CRXRdy/Rdy cats was more severe compared to CRXRdy/+ cats by several metrics. Translational Relevance The CRX-mutant cat is the only model for CRX-retinopathies with a macula-equivalent region. A prominent feature of the CRXRdy/Rdy cat phenotype not detectable in homozygous mouse models was the rapid degeneration of the macula-equivalent retinal region highlighting the value of this large animal model and its future importance in the testing of translational therapies aiming to restore vision.
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Affiliation(s)
- Laurence M. Occelli
- Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - Nicholas M. Tran
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Shiming Chen
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
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2
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Sirés A, Turch-Anguera M, Bogdanov P, Sampedro J, Ramos H, Ruíz Lasa A, Huo J, Xu S, Lam KP, López-Soriano J, Pérez-García MJ, Hernández C, Simó R, Solé M, Comella JX. Faim knockout leads to gliosis and late-onset neurodegeneration of photoreceptors in the mouse retina. J Neurosci Res 2021; 99:3103-3120. [PMID: 34713467 DOI: 10.1002/jnr.24978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/13/2021] [Accepted: 09/21/2021] [Indexed: 01/08/2023]
Abstract
Fas Apoptotic Inhibitory Molecule protein (FAIM) is a death receptor antagonist and an apoptosis regulator. It encodes two isoforms, namely FAIM-S (short) and FAIM-L (long), both with significant neuronal functions. FAIM-S, which is ubiquitously expressed, is involved in neurite outgrowth. In contrast, FAIM-L is expressed only in neurons and it protects them from cell death. Interestingly, FAIM-L is downregulated in patients and mouse models of Alzheimer's disease before the onset of neurodegeneration, and Faim transcript levels are decreased in mouse models of retinal degeneration. However, few studies have addressed the role of FAIM in the central nervous system, yet alone the retina. The retina is a highly specialized tissue, and its degeneration has proved to precede pathological mechanisms of neurodegenerative diseases. Here we describe that Faim depletion in mice damages the retina persistently and leads to late-onset photoreceptor death in older mice. Immunohistochemical analyses showed that Faim knockout (Faim-/- ) mice present ubiquitinated aggregates throughout the retina from early ages. Moreover, retinal cells released stress signals that can signal to Müller cells, as shown by immunofluorescence and qRT-PCR. Müller cells monitor retinal homeostasis and trigger a gliotic response in Faim-/- mice that becomes pathogenic when sustained. In this regard, we observed pronounced vascular leakage at later ages, which may be caused by persistent inflammation. These results suggest that FAIM is an important player in the maintenance of retinal homeostasis, and they support the premise that FAIM is a plausible early marker for late photoreceptor and neuronal degeneration.
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Affiliation(s)
- Anna Sirés
- Cell Signaling and Apoptosis Group, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain.,Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - Mireia Turch-Anguera
- Cell Signaling and Apoptosis Group, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.,Diabetes and Metabolism Research Unit, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, Madrid, Spain
| | - Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, Madrid, Spain
| | - Joel Sampedro
- Diabetes and Metabolism Research Unit, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, Madrid, Spain
| | - Hugo Ramos
- Diabetes and Metabolism Research Unit, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, Madrid, Spain
| | - Agustín Ruíz Lasa
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain.,Research Center and Memory Clinic. Fundació ACE, Institut Català de Neurociències Aplicades, Universitat Internacional de Catalunya (UIC), Barcelona, Spain
| | - Jianxin Huo
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Singapore, Singapore
| | - Shengli Xu
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Singapore, Singapore
| | - Kong-Peng Lam
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Singapore, Singapore
| | - Joaquín López-Soriano
- Cell Signaling and Apoptosis Group, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain.,Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - M Jose Pérez-García
- Cell Signaling and Apoptosis Group, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, Madrid, Spain
| | - Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, Madrid, Spain
| | - Montse Solé
- Cell Signaling and Apoptosis Group, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain.,Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - Joan X Comella
- Cell Signaling and Apoptosis Group, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain.,Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
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3
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Leiton CV, Chen E, Cutrone A, Conn K, Mellanson K, Malik DM, Klingener M, Lamm R, Cutrone M, Petrie J, Sheikh J, DiBua A, Cohen B, Floyd TF. Astrocyte HIF-2α supports learning in a passive avoidance paradigm under hypoxic stress. HYPOXIA (AUCKLAND, N.Z.) 2018; 6:35-56. [PMID: 30519596 PMCID: PMC6234990 DOI: 10.2147/hp.s173589] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The brain is extensively vascularized, useŝ20% of the body's oxygen, and is highly sensitive to changes in oxygen. While synaptic plasticity and memory are impaired in healthy individuals by exposure to mild hypoxia, aged individuals appear to be even more sensitive. Aging is associated with progressive failure in pulmonary and cardiovascular systems, exposing the aged to both chronic and superimposed acute hypoxia. The HIF proteins, the "master regulators" of the cellular response to hypoxia, are robustly expressed in neurons and astrocytes. Astrocytes support neurons and synaptic plasticity via complex metabolic and trophic mechanisms. The activity of HIF proteins in the brain is diminished with aging, and the increased exposure to chronic and acute hypoxia with aging combined with diminished HIF activity may impair synaptic plasticity. PURPOSE Herein, we test the hypothesis that astrocyte HIF supports synaptic plasticity and learning upon hypoxia. MATERIALS AND METHODS An Astrocyte-specific HIF loss-of-function model was employed, where knock-out of HIF-1α or HIF-2α in GFAP expressing cells was accomplished by cre-mediated recombination. Animals were tested for behavioral (open field and rotarod), learning (passive avoidance paradigm), and electrophysiological (long term potentiation) responses to mild hypoxic challenge. RESULTS In an astrocyte-specific HIF loss-of-function model followed by mild hypoxia, we identified that the depletion of HIF-2α resulted in an impaired passive avoidance learning performance. This was accompanied by an attenuated response to induction in long-term potentiation (LTP), suggesting that the hippocampal circuitry was perturbed upon hypoxic exposure following HIF-2α loss in astrocytes, and not due to hippocampal cell death. We investigated HIF-regulated trophic and metabolic target genes and found that they were not regulated by HIF-2α, suggesting that these specific targets may not be involved in mediating the phenotypes observed. CONCLUSION Together, these results point to a role for HIF-2α in the astrocyte's regulatory role in synaptic plasticity and learning under hypoxia and suggest that even mild, acute hypoxic challenges can impair cognitive performance in the aged population who harbor impaired HIF function.
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Affiliation(s)
- Cindy V Leiton
- Department of Pathology, Stony Brook University, Stony Brook, NY, USA
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, USA
| | - Elyssa Chen
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, USA
| | - Alissa Cutrone
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kristy Conn
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, USA
| | - Kennelia Mellanson
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Dania M Malik
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Klingener
- Department of Genetics, Stony Brook University, Stony Brook, NY, USA
| | - Ryan Lamm
- Department of General Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Michael Cutrone
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - John Petrie
- Department of Biochemistry & Molecular Biology, Bloomberg School of Public health, Johns Hopkins University, Baltimore, MD, USA
| | - Joher Sheikh
- Department of Physiology and Biophysics, Georgetown University, Washington, DC, USA
| | - Adriana DiBua
- Department of Chemistry, Hofstra University, Hempstead, NY, USA
| | - Betsy Cohen
- Computer Science Department, Swarthmore College, Swarthmore, PA, USA
| | - Thomas F Floyd
- Department of Anesthesiology and Pain Management, University of Texas Southwestern, Dallas, TX, USA,
- Department of Cardiothoracic Surgery, University of Texas Southwestern, Dallas, TX, USA,
- Department of Radiology, University of Texas Southwestern, Dallas, TX, USA,
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4
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Occelli LM, Schön C, Seeliger MW, Biel M, Michalakis S, Petersen-Jones SM. Gene Supplementation Rescues Rod Function and Preserves Photoreceptor and Retinal Morphology in Dogs, Leading the Way Toward Treating Human PDE6A-Retinitis Pigmentosa. Hum Gene Ther 2017; 28:1189-1201. [PMID: 29212382 DOI: 10.1089/hum.2017.155] [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] [Indexed: 11/12/2022] Open
Abstract
Mutations in the phosphodiesterase 6A gene (PDE6A) result in retinitis pigmentosa (RP) type 43 (RP43) and are responsible for about 4% of autosomal recessive RP. There is currently no treatment for this blinding condition. The aim of this project was to use a large-animal model to test a gene supplementation viral vector designed to be translated for use in a clinical trial for the treatment of RP43. Seven Pde6a-/- puppies were given sub-retinal injections of an adeno-associated viral vector (AAV) serotype 2/8 delivering human PDE6A cDNA under control of a short rhodopsin promoter (AAV8-PDE6A). Three puppies received ∼1 × 1011 vg in one eye and four puppies ∼5 × 1011 vg/per eye, with both eyes being injected in two animals. In vivo outcome measures included vision testing and electroretinography (ERG), as well as fundus and spectral domain-optical coherence tomography imaging. Some puppies were euthanized and their eyes processed for immunohistochemistry. All puppies had improved rod-mediated vision in the treated eye. ERGs showed improved rod-mediated responses in the higher-dose group but in only one of the lower-dose group animals. Receptor+ thickness was preserved and photoreceptor morphology improved in the treated retinal regions in all puppies. Treatment resulted in PDE6A transgene expression, accompanied by much increased levels of Pde6b, in rod outer segments in the injected retinal regions. There were several indications of improved retinal health in the PDE6A-expressing regions, including lack of abnormal cyclic guanosine monophosphate accumulation, appropriate rod opsin localization to the outer segments with a large reduction in mislocalization to other regions of the rod cell, and reduced Müller cell activation. Additionally, cone photoreceptors showed morphological improvement in the treated region, with normal-appearing inner and outer segments. AAV8-PDE6A gene supplementation therapy restored rod vision in Pde6a-/- puppies and preserved retinal morphology. These positive outcomes are an important step toward a human clinical trial to treat PDE6A-RP.
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Affiliation(s)
- Laurence M Occelli
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan
| | - Christian Schön
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University, Tuebingen, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan
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5
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Occelli LM, Tran NM, Narfström K, Chen S, Petersen-Jones SM. CrxRdy Cat: A Large Animal Model for CRX-Associated Leber Congenital Amaurosis. Invest Ophthalmol Vis Sci 2017; 57:3780-92. [PMID: 27427859 PMCID: PMC4960999 DOI: 10.1167/iovs.16-19444] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Purpose Mutations in the retinal transcription factor cone-rod homeobox (CRX) gene result in severe dominant retinopathies. A large animal model, the Rdy cat, carrying a spontaneous frameshift mutation in Crx, was reported previously. The present study aimed to further understand pathogenesis in this model by thoroughly characterizing the Rdy retina. Methods Structural and functional changes were found in a comparison between the retinas of CrxRdy/+ kittens and those of wild-type littermates and were determined at various ages by fundus examination, electroretinography (ERG), optical coherence tomography, and histologic analyses. RNA and protein expression changes of Crx and key target genes were analyzed using quantitative reverse-transcribed PCR, Western blot analysis, and immunohistochemistry. Transcription activity of the mutant Crx was measured by a dual-luciferase transactivation assay. Results CrxRdy/+ kittens had no recordable cone ERGs. Rod responses were delayed in development and markedly reduced at young ages and lost by 20 weeks. Photoreceptor outer segment development was incomplete and was followed by progressive outer retinal thinning starting in the cone-rich area centralis. Expression of cone and rod Crx target genes was significantly down-regulated. The mutant Crx allele was overexpressed, leading to high levels of the mutant protein lacking transactivation activity. Conclusions The CrxRdy mutation exerts a dominant negative effect on wild-type Crx by overexpressing mutant protein. These findings, consistent with those of studies in a mouse model, support a conserved pathogenic mechanism for CRX frameshift mutations. The similarities between the feline eye and the human eye with the presence of a central region of high cone density makes the CrxRdy/+ cat a valuable model for preclinical testing of therapies for dominant CRX diseases.
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Affiliation(s)
- Laurence M Occelli
- Small Animal Clinical Sciences Michigan State University, East Lansing, Michigan, United States
| | - Nicholas M Tran
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Kristina Narfström
- Department of Veterinary Medicine and Surgery, University of Missouri-Columbia, Columbia, Missouri, United States
| | - Shiming Chen
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Simon M Petersen-Jones
- Small Animal Clinical Sciences Michigan State University, East Lansing, Michigan, United States
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6
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7
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Coorey NJ, Shen W, Chung SH, Zhu L, Gillies MC. The role of glia in retinal vascular disease. Clin Exp Optom 2012; 95:266-81. [PMID: 22519424 DOI: 10.1111/j.1444-0938.2012.00741.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Retinal vascular diseases collectively represent a leading cause of blindness. Unsurprisingly, pathological characterisation and treatment of retinal 'vascular' diseases have primarily focused on the aetiology and consequences of vascular dysfunction. Far less research has addressed the contribution of neuronal and glial dysfunction to the disease process of retinal vascular disorders. Ample evidence now suggests that retinal vasculopathy only uncommonly occurs in isolation, usually existing in concert with neuropathy and gliopathy. Retinal glia (Müller cells, astrocytes and microglia) have been reported to exhibit morphological and functional changes in both early and advanced phases of almost every retinal vascular disease. It is anticipated that identifying the causes of glial activation and dysfunction, and their contribution to loss of vision in retinal vascular disease, will lead to a better understanding of retinal vascular diseases, which might ultimately be translated into novel clinical therapies.
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Affiliation(s)
- Nathan J Coorey
- Save Sight Institute, The University of Sydney, Sydney, Australia
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8
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Cho W, Hagemann TL, Johnson DA, Johnson JA, Messing A. Dual transgenic reporter mice as a tool for monitoring expression of glial fibrillary acidic protein. J Neurochem 2009; 110:343-51. [PMID: 19457099 DOI: 10.1111/j.1471-4159.2009.06146.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Glial fibrillary acidic protein (GFAP) is the major intermediate filament protein of astrocytes, and its expression changes dramatically during development and following injury. To facilitate study of the regulation of GFAP expression, we have generated dual transgenic mice expressing both firefly luciferase under the control of a 2.2 kb human GFAP promoter and Renilla luciferase under the control of a 0.5 kb human Glyceraldehyde 3 phosphate dehydrogenase (GAPDH) promoter for normalization of the GFAP signal. The GFAP-fLuc was highly expressed in brain compared to other tissues, and was limited to astrocytes, whereas the GAPDH-RLuc was more widely expressed. Normalization of the GFAP signal to the GAPDH signal reduced the inter-individual variability compared to using the GFAP signal alone. The GFAP/GAPDH ratio correctly reflected the up-regulation of GFAP that occurs following retinal degeneration in FVB/N mice because of the rd mutation. Following kainic acid-induced seizures, changes in the GFAP/GAPDH ratio precede those in total GFAP protein. In knock-in mice expressing the R236H Alexander disease mutant, GFAP promoter activity is only transiently elevated and may not entirely account for the accumulation of GFAP protein that takes place.
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Affiliation(s)
- Woosung Cho
- Waisman Center and Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.
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9
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Tuntivanich N, Pittler SJ, Fischer AJ, Omar G, Kiupel M, Weber A, Yao S, Steibel JP, Khan NW, Petersen-Jones SM. Characterization of a canine model of autosomal recessive retinitis pigmentosa due to a PDE6A mutation. Invest Ophthalmol Vis Sci 2009; 50:801-13. [PMID: 18775863 PMCID: PMC3720143 DOI: 10.1167/iovs.08-2562] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize a canine model of autosomal recessive RP due to a PDE6A gene mutation. METHODS Affected and breed- and age-matched control puppies were studied by electroretinography (ERG), light and electron microscopy, immunohistochemistry, and assay for retinal PDE6 levels and enzymatic activity. RESULTS The mutant puppies failed to develop normal rod-mediated ERG responses and had reduced light-adapted a-wave amplitudes from an early age. The residual ERG waveforms originated primarily from cone-driven responses. Development of photoreceptor outer segments stopped, and rod cells were lost by apoptosis. Immunohistochemistry demonstrated a marked reduction in rod opsin immunostaining outer segments and relative preservation of cones early in the disease process. With exception of rod bipolar cells, which appeared to be reduced in number relatively early in the disease process, other inner retinal cells were preserved in the early stages of the disease, although there was marked and early activation of Müller glia. Western blot analysis showed that the PDE6A mutation not only resulted in a lack of PDE6A protein but the affected retinas also lacked the other PDE6 subunits, suggesting expression of PDE6A is essential for normal expression of PDE6B and PDE6G. Affected retinas lacked PDE6 enzymatic activity. CONCLUSIONS This represents the first characterization of a PDE6A model of autosomal recessive retinitis pigmentosa, and the PDE6A mutant dog shows promise as a large animal model for investigation of therapies to rescue mutant rod photoreceptors and to preserve cone photoreceptors in the face of a rapid loss of rod cells.
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Affiliation(s)
- Nalinee Tuntivanich
- Department of Small Animal Clinical Studies, Michigan State University, East Lansing, Michigan 48824, USA
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10
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Leukemia inhibitory factor extends the lifespan of injured photoreceptors in vivo. J Neurosci 2009; 28:13765-74. [PMID: 19091967 DOI: 10.1523/jneurosci.5114-08.2008] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Survival and death of photoreceptors in degenerative diseases of the retina is controlled by a multitude of genes and endogenous factors. Some genes may be involved in the degenerative process itself whereas others may be part of an endogenous defense system. We show in two models of retinal degeneration that photoreceptor death strongly induces expression of leukemia inhibitory factor (LIF) in a subset of Muller glia cells in the inner nuclear layer of the retina. LIF expression is essential to induce an extensive intraretinal signaling system which includes Muller cells and photoreceptors and is characterized by an upregulation of Edn2, STAT3, FGF2 and GFAP. In the absence of LIF, Muller cells remain quiescent, the signaling system is not activated and retinal degeneration is strongly accelerated. Intravitreal application of recombinant LIF induces the full molecular pathway including the activation of Muller cells in wild-type and Lif(-/-) mice. Interruption of the signaling cascade by an Edn2 receptor antagonist increases whereas activation of the receptor decreases photoreceptor cell death. Thus, LIF is essential and sufficient to activate an extensive molecular defense response to photoreceptor injury. Our data establish LIF as a Muller cell derived neuronal survival factor which controls an intrinsic protective mechanism that includes Edn2 signaling to support photoreceptor cell survival and to preserve vision in the injured retina.
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Zou W, Kim BO, Zhou BY, Liu Y, Messing A, He JJ. Protection against human immunodeficiency virus type 1 Tat neurotoxicity by Ginkgo biloba extract EGb 761 involving glial fibrillary acidic protein. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:1923-35. [PMID: 18055541 DOI: 10.2353/ajpath.2007.070333] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human immunodeficiency virus (HIV)-1 Tat protein is an important pathogenic factor in HIV-associated neuropathogenesis. Despite recent progress, the molecular mechanisms underlying Tat neurotoxicity are still not completely understood. However, few therapeutics have been developed to specifically target HIV infection in the brain. Recent development of an inducible brain-specific Tat transgenic mouse model has made it possible to define the mechanisms of Tat neurotoxicity and evaluate anti-neuroAIDS therapeutic candidates in the context of a whole organism. Herein, we demonstrate that administration of EGb 761, a standardized formulation of Ginkgo biloba extract, markedly protected Tat transgenic mice from Tat-induced developmental retardation, inflammation, death, astrocytosis, and neuron loss. EGb 761 directly down-regulated glial fibrillary acidic protein (GFAP) expression at both protein and mRNA levels. This down-regulation was, at least in part, attributable to direct effects of EGb 761 on the interactions of the AP1 and NF-kappaB transcription factors with the GFAP promoter. Most strikingly, Tat-induced neuropathological phenotypes including macrophage/microglia activation, central nervous system infiltration of T lymphocytes, and oxidative stress were significantly alleviated in GFAP-null/Tat transgenic mice. Taken together, these results provide the first evidence to support the potential for clinical use of EGb 761 to treat HIV-associated neurological diseases. Moreover, these findings suggest for the first time that GFAP activation is directly involved in Tat neurotoxicity, supporting the notion that astrocyte activation or astrocytosis may directly contribute to HIV-associated neurological disorders.
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Affiliation(s)
- Wei Zou
- Department of Microbiology and Immunology, Indiana University School of Medicine, R2 302, 950 W. Walnut St., Indianapolis, IN 46202, USA
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12
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Fimbel SM, Montgomery JE, Burket CT, Hyde DR. Regeneration of inner retinal neurons after intravitreal injection of ouabain in zebrafish. J Neurosci 2007; 27:1712-24. [PMID: 17301179 PMCID: PMC6673754 DOI: 10.1523/jneurosci.5317-06.2007] [Citation(s) in RCA: 227] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
We examined the regenerative capacity of the adult zebrafish retina by intravitreal injection of a low ouabain concentration to rapidly damage the ganglion cell layer (GCL) and inner nuclear layer (INL) with minimal photoreceptor cell damage. By 24 h after ouabain injection, maximal numbers of terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL)-positive cells were detected in the INL and GCL, with low numbers of TUNEL-positive cells in the outer nuclear layer. Immunolabeling revealed that approximately 85% of the HuC/D-positive amacrine and ganglion cells were lost by 7 d post-ouabain injection (dpi). This ganglion cell loss was consistent with the small, but statistically significant, decrease in the optic nerve diameter. The regeneration response began within 1 dpi with increased proliferating cell nuclear antigen (PCNA) expression in both the INL and GCL. By 3 dpi, PCNA expression is primarily restricted to the Müller glia. By 5 dpi, most of the PCNA expression was localized to neuronal progenitors expressing the olig2:egfp transgene rather than the Müller glia. By 7 dpi, the neuronal progenitors began committing to the ganglion cell fate based on the coexpression of the atoh7:EGFP transgene and the zn5 antigen. The regeneration of ganglion and amacrine cells continued until 60 dpi, when they reached 75% of their uninjected control number. This demonstrates that inner retinal damage, without extensive photoreceptor damage, is sufficient to induce a regeneration response that is marked by the Müller glial cells reentering the cell cycle to produce neuronal progenitor cells that regenerate INL and ganglion cells in the zebrafish retina.
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Affiliation(s)
- Shane M. Fimbel
- Department of Biological Sciences and Center for Zebrafish Research, University of Notre Dame, Notre Dame, Indiana 46556
| | - Jacob E. Montgomery
- Department of Biological Sciences and Center for Zebrafish Research, University of Notre Dame, Notre Dame, Indiana 46556
| | - Christopher T. Burket
- Department of Biological Sciences and Center for Zebrafish Research, University of Notre Dame, Notre Dame, Indiana 46556
| | - David R. Hyde
- Department of Biological Sciences and Center for Zebrafish Research, University of Notre Dame, Notre Dame, Indiana 46556
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Ramírez AI, Salazar JJ, De Hoz R, Rojas B, Ruiz E, Tejerina T, Ramírez JM, Triviño A. Macroglial and retinal changes in hypercholesterolemic rabbits after normalization of cholesterol levels. Exp Eye Res 2006; 83:1423-38. [PMID: 17007836 DOI: 10.1016/j.exer.2006.07.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 07/03/2006] [Accepted: 07/22/2006] [Indexed: 11/21/2022]
Abstract
This study evaluates hypercholesterolemic rabbits, examining the retinal changes in Müller cells and astrocytes as well as their variations after a period of normal blood-cholesterol values induced by a standard diet. New Zealand rabbits were divided into three groups: G0, fed a standard diet; G1A, fed a 0.5% cholesterol-enriched diet for 8 months; and G1B, fed as G1A followed by standard diet for 6 months. Eyes were processed for transmission electron microscopy and immunohistochemistry (GFAP). While G1B resembled G0 more than did G1A, they shared alterations with G1A: a) as in G1A, Müller cells were GFAP+, filled spaces left by axonal degeneration, formed glial scars and their nuclei were displaced to the nerve-fibre layer. The area occupied by the astrocytes associated with the nerve-fibre bundles (AANFB) and by perivascular astrocytes (PVA) in G1A and G1B was significantly lower than in controls. However, no significant differences in PVA were found between G1A and G1B. In G1B, type I PVA was absent and replaced by hypertrophic type II cells; b) Bruch's membrane (BM) was thinner in G1B than in G1A; c) the retinal pigment epithelium (RPE) cytoplasm contained fewer lipids in G1B than in G1A; d) in G1A and G1B choriocapillaris and retinal vessel showed alterations with respect to G0; e) cell death and axonal degeneration in the retina were similar in G1A and G1B. The substitution of a hyperlipemic diet by a standard one normalizes blood-lipid levels. However, the persistence of damage at retinal vessels and BM-RPE could trigger chronic ischemia.
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Affiliation(s)
- Ana I Ramírez
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, School of Medicine, Complutense University, Ciudad Universitaria s/n UCM, Madrid, Spain.
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Lewis GP, Fisher SK. Up-Regulation of Glial Fibrillary Acidic Protein in Response to Retinal Injury: Its Potential Role in Glial Remodeling and a Comparison to Vimentin Expression. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 230:263-90. [PMID: 14692684 DOI: 10.1016/s0074-7696(03)30005-1] [Citation(s) in RCA: 266] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Intermediate filament proteins are a heterogeneous group of proteins that form 10-nm-diameter filaments, a highly stable cytoskeletal component occurring in various cell types. The up-regulation of one of these intermediate filament proteins, glial fibrillary acidic protein (GFAP), historically has been an indicator of "stress" in central nervous system (CNS) astrocytes. The retina also responds similarly to "stress" but the up-regulation of intermediate filaments occurs primarily in the Müller cells, the radial glia of the retina. This is a remarkably ubiquitous response in that a similar up-regulation can be observed in numerous forms of retinal degeneration. As a consequence of retinal detachment, a "mechanical" injury to the retina, GFAP, and another intermediate filament protein, vimentin, dramatically increase in Müller cells. Concomitant with this up-regulation is the hypertrophy of these cells both within the retina and onto the photoreceptor and vitreal surfaces of the retina. The function of this distinctive intermediate filament up-regulation in glial cells is unknown, but in the retina their expression is differentially regulated in a polarized manner as the Müller cells hypertrophy, suggesting that they play some role in this process. Moreover the response of intermediate filaments and the Müller cells differs depending on whether the retina has been detached or reattached to the retinal pigment epithelium. The differential expression of these proteins may give insight into their role in the formation of glial scars in the retina and elsewhere in the CNS.
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Affiliation(s)
- Geoffrey P Lewis
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California 93106, USA
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Jones SE, Jomary C, Grist J, Stewart HJ, Neal MJ. Identification by array screening of altered nm23-M2/PuF mRNA expression in mouse retinal degeneration. MOLECULAR CELL BIOLOGY RESEARCH COMMUNICATIONS : MCBRC 2000; 4:20-5. [PMID: 11152623 DOI: 10.1006/mcbr.2000.0250] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the rd/rd mouse model of inherited retinal degeneration, the majority of photoreceptors die apoptotically between postnatal age (P)10 and 20 days, during which period the inner retina appears morphologically unaffected. To examine mRNA changes associated with the degeneration, we performed differential screening of 588 arrayed murine cDNAs using probes reverse-transcribed from P8 predegenerative and control mouse retinal RNAs. We detected altered expression of the gene encoding nm23-M2, a member of the family of nucleoside diphosphate kinases implicated in diverse processes including metastasis suppression and transcriptional regulation. Retinal nm23 mRNA levels increased during degeneration while control levels decreased over age-matched time-points. In situ hybridization showed the high level of expression at P20 in rd/rd was concentrated in the retinal ganglion cells. Previous studies have indicated upregulation of the stress-response related gene alphaB-crystallin in the rd/rd inner retina, and increased nm23 levels may be a component of this response to photoreceptor loss and altered retinal architecture.
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Affiliation(s)
- S E Jones
- Retinitis Pigmentosa Research Unit, The Rayne Institute, London, SE1 7EH, United Kingdom
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Zrenner E, Stett A, Weiss S, Aramant RB, Guenther E, Kohler K, Miliczek KD, Seiler MJ, Haemmerle H. Can subretinal microphotodiodes successfully replace degenerated photoreceptors? Vision Res 1999; 39:2555-67. [PMID: 10396624 DOI: 10.1016/s0042-6989(98)00312-5] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The idea of implanting microphotodiode arrays as visual prostheses has aroused controversy on its feasibility from the moment it appeared in print. We now present results which basically support the concept of replacing damaged photoreceptors with subretinally implanted stimulation devices. Network activity in degenerated rat retinae could be modulated through local electrical stimulation in vitro. We also investigated the long term stability and biocompatibility of the subretinal implants and their impact on retinal physiology in rats. Ganzfeld electroretinograms and histology showed no significant side effect of subretinal implants on retinal function or the architecture of the inner retina.
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Affiliation(s)
- E Zrenner
- University Eye Hospital, Department II, Tuebingen, Germany.
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17
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Jones SE, Jomary C, Grist J, Thomas MR, Neal MJ. Expression of alphaB-crystallin in a mouse model of inherited retinal degeneration. Neuroreport 1998; 9:4161-5. [PMID: 9926867 DOI: 10.1097/00001756-199812210-00030] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AlphaB-crystallin, which is abundantly expressed in the lens but also in a diversity of other tissues, functions as a stress-inducible molecular chaperone and is increased in brain neurodegenerative diseases. We compared retinal alphaB-crystallin expression in a model of inherited retinal degeneration, the rd mouse, and controls. Northern and in situ hybridization analysis showed alphaB-crystallin mRNA to have an altered spatio-temporal pattern with increased levels localized to glial cells in the degenerative state. Immunocytochemistry confirmed increased expression at Müller cells and astrocytes, together with transiently increased localization to the degenerating photoreceptors. These findings suggest that increased alphaB-crystallin expression is associated with glial cell reaction to neuronal damage in the retina, and may comprise part of the retina's overall defensive response to the stress of apoptotic photoreceptor cell death.
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Affiliation(s)
- S E Jones
- British Retinitis Pigmentosa Society Laboratory, Department of Pharmacology, GKT, The Rayne Institute, St Thomas' Hospital, London, UK
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18
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Zhuo L, Sun B, Zhang CL, Fine A, Chiu SY, Messing A. Live astrocytes visualized by green fluorescent protein in transgenic mice. Dev Biol 1997; 187:36-42. [PMID: 9224672 DOI: 10.1006/dbio.1997.8601] [Citation(s) in RCA: 295] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Green fluorescent protein (hGFP-S65T) was expressed in transgenic mice under the control of the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter. Tissues from two independent transgenic lines were characterized by Northern blot analysis and by confocal microscopy. The expression pattern in these two lines was identical in all tissues examined, and similar to that found previously with a lacZ transgene driven by the same promoter. Bright fluorescence was observed in the cell bodies and processes of unfixed or fixed astrocytes, using both whole mount and brain slice preparations, from multiple areas of the central nervous system. However, in contrast to GFAP-lacZ transgenics, retinal Müller cells expressed the GFP transgene in response to degeneration of neighboring photoreceptors. These data indicate that the 2.2-kb hGFAP promoter contains sufficient regulatory elements to direct expression in Müller cells, and that GFP is a suitable reporter gene for use in living preparations of the mammalian nervous system. Such mice should prove useful for studies of dynamic changes in astrocyte morphology during development, and in response to physiological and pathological conditions.
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Affiliation(s)
- L Zhuo
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 53706, USA
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19
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Sarthy V, Bickoff C. Immunocytochemical localization of retinoid-binding protein in the dogfish retina. Curr Eye Res 1996; 15:905-7. [PMID: 8921235 DOI: 10.3109/02713689609017633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE The cellular localization of retinoid-binding proteins has been extensively studied in the mammalian retina. Less is known about the distribution and identity of retinoid-binding proteins in lower vertebrate retinas. To understand their cellular functions, we have examined the distribution of specific retinoid-binding proteins in the neural retina and RPE of an elasmobranch, the dogfish. METHODS Retinoid-binding proteins were localized in cryostat sections of dogfish eyes by the indirect immunofluorescence technique. We used well-characterized antibodies that have been previously employed for immunostaining. Immunoblotting was carried out to identify the antigen. RESULTS The studies show that the cellular retinaldehyde-binding protein is present in the RPE and retinal Müller cells, and the interphotoreceptor retinoid-binding protein is found in the interstitial space between pigment epithelium and retina. CONCLUSIONS The distribution of retinoid-binding proteins in dogfish retina is similar to that found in the mammalian retina which suggests that the sites of action of the retinoid-binding proteins are highly conserved in vertebrates.
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Affiliation(s)
- V Sarthy
- Department of Ophthalmology, Northwestern University Medical School, Chicago, IL 60611, USA
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20
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MacLaren RE. Development and role of retinal glia in regeneration of ganglion cells following retinal injury. Br J Ophthalmol 1996; 80:458-64. [PMID: 8695569 PMCID: PMC505499 DOI: 10.1136/bjo.80.5.458] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
AIMS/BACKGROUND Recent observations have shown that the glial scar resulting from a surgical lesion of the immature retina differs from elsewhere in the central nervous system, in that it permits the through growth and reconnection of regenerating axons. This study in the opossum examines in detail the development and reaction to injury of retinal glia at different developmental stages, and specifically examines the distribution of the gliosis related inhibitory molecule, chondroitin sulphate proteoglycan (CSPG), making comparisons with a control site of gliosis in the cerebral cortex. METHODS A linear slit was cut into the retina or cortex with a fine tungsten probe. After a variable time delay, immunocytochemistry of the resulting gliosis was employed to detect astrocytes with glial fibrillary acidic protein (GFAP), Müller cells with vimentin, and CSPG with CS-56 antibodies. GFAP was also used at different ages to examine the normal development of astrocytes in the retina of this species. RESULTS Astrocytes entered the retina 12 days after birth (P12), closely associated with blood vessels in the nerve fibre layer. In experiments at all ages studied, cellular continuity was re-established across the lesioned retina, which did not result in a significant astrocyte proliferation or CSPG expression. In contrast, cortical injury led to the development of a cystic cavity surrounded by astrocytes and CSPG. Müller cells expressed GFAP but not CSPG in the lesioned retina. CONCLUSION Successful regrowth of ganglion cells through a retinal lesion may be partly the result of the scarcity of astrocytes in the retina, which results in minimal gliosis, or of their apparent inability to express inhibitory molecules.
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Affiliation(s)
- R E MacLaren
- Department of Human Anatomy, University of Oxford
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21
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Abstract
There is a very wide spread Müller glial response to focal laser photocoagulation lesions in the rabbit retina. In this study we have described the microglial response to similar lesions and compared this with the Müller and retinal ganglion cell responses. Microglia were labelled using nucleoside di-phosphatase histochemistry in adult rabbit retinal wholemounts and compared with axonal and Müller cell responses as shown respectively by neurofilament and GFAP immunohistochemistry. In the normal retina, microglia were located in the nerve fibre layer (NFL), inner plexiform layer (IPL), and sparsely in the outer plexiform layer (OPL). Following laser photocoagulation each layer reacted differently. The NFL reaction was exclusively associated with axonal degeneration, as shown by abnormal neurofilament label, and therefore only started several days after injury. In the IPL, neighbouring microglial cells directed their processes towards the lesion by 2 h and had migrated into the lesion by 6 h, but the reaction did not extend more than 2-3 cell diameters from the lesion and was over by 7 days. In the OPL the cell density increased by 1-2 days over a few millimeters from the lesion. The Müller cells expressed GFAP for several millimeters from the lesion starting at 24 h and persisting for over one month and therefore the correlation with the microglial reaction was poor. The different reaction in each retinal layer is evidence that microglial responses are modulated by local factors, probably mainly by contact with injured retinal elements as well as diffusable factors.
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Affiliation(s)
- M F Humphrey
- WARP Research Centre, Lions Eye Institute, University of Western Australia, Nedlands
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Drescher KM, Whittum-Hudson JA. Modulation of immune-associated surface markers and cytokine production by murine retinal glial cells. J Neuroimmunol 1996; 64:71-81. [PMID: 8598392 PMCID: PMC7119802 DOI: 10.1016/0165-5728(95)00156-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Murine retinal glia are normally negative for major histocompatibility complex (MHC) Class II antigens and express low levels of MHC Class I and intercellular adhesion molecule-1 (ICAM-1) as detected by avidin-biotin-peroxidase immunohistochemistry. These surface molecules associated with immune function were either induced (Class II) or upregulated (Class I and ICAM-1) on cultured retinal glial cells in a dose- and time-dependent manner following exposure to recombinant interferon-gamma (rIFN-gamma). MHC Class I and II expression by passaged and primary cells was maximal (> 90% positive) after incubation with 100 U/m1 of rIFN-gamma for 48 h. ICAM-1 expression by primary and passaged cells tripled between 48 and 72 h after exposure to 25 or 50 U/m1 of rIFN-gamma. By 72 h after exposure to 100 U/m1 of rIFN-gamma, 62% of the retinal glia were positive for ICAM-1, whereas under normal culture conditions these molecules were detected on < 3% of the retinal glia. Bacterial lipopolysaccharide (LPS), a known stimulator of central nervous system (CNS) astrocytes, increased ICAM-1 expression only 3-fold to 9% of cells staining positively, but neither MHC Class I nor Class II expression was altered from baseline levels. Surface expression of ICAM-1, MHC Class I, and MHC Class II was unaffected by exposure to either rTNF-alpha (1000 U/m1) or rIL-6 (100 U/m1) for 24 h. Under normal culture conditions, intracellular interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were detected immunohistochemically. Exposure to either rIFN-gamma or LPS induced more intense staining which correlated with increased secreted levels of both cytokines in culture supernatants. Levels of secreted TNF-alpha increased 6-fold after stimulation with LPS for 24 h, while secreted IL-6 increased over 9-fold. These results support the hypothesis that retinal glia may participate in intraretinal immune processes following stimulation during inflammatory and infections processes via either cell surface-or soluble mediator-dependent mechanisms or a combination of both.
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Affiliation(s)
- K M Drescher
- Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
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DiLoreto DA, Martzen MR, del Cerro C, Coleman PD, del Cerro M. Müller cell changes precede photoreceptor cell degeneration in the age-related retinal degeneration of the Fischer 344 rat. Brain Res 1995; 698:1-14. [PMID: 8581466 DOI: 10.1016/0006-8993(95)00647-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Previously, we have used descriptive pathology and histomorphometry, as well as functional testing to characterize the age-related retinal degeneration in the Fischer 344 rat. These studies suggested an association between Müller cells and photoreceptor cells in this process. The purpose of the present study was to further investigate the respective roles of these cell types in the development and progression of the retinal degeneration. Retinas from male Fischer 344 rats aged 3-24 months were first studied by light and electron microscopy. Since Müller cells abundantly express GFAP during pathological states, GFAP content was studied by immunocytochemistry and by immunoblotting following one- and two-dimensional gel electrophoresis. Microscopically, at 12 months, Müller cells showed a gradient of immunoreactivity for GFAP that was minimal in the central retina, positive for their radial processes in the equator, and abundantly expressed in the periphery. At this age, the photoreceptor cells were just beginning to degenerate in the far periphery, while they appeared healthy in the equatorial and central regions. By 24 months, Müller cell hypertrophy was seen in the peripheral regions where photoreceptor cell degeneration was most severe, while the immunoreactivity of the Müller cell processes spread further toward the central regions, ahead of the degeneration of the photoreceptor cells. Thus, Müller cell changes actually preceded photoreceptor degeneration in time and location. This phenomenon was confirmed by measurement of GFAP after one- and two-dimensional PAGE. These findings show that Müller cell changes precede chronic photoreceptor cell degeneration in the aging Fischer 344 rat and are consistent with the hypothesis that Müller cell alteration may be the primary mechanism of this age-related retinal degeneration.
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Affiliation(s)
- D A DiLoreto
- Department of Neurobiology, University of Rochester School of Medicine and Dentistry, NY 14642, USA
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24
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Abstract
The present study aimed to characterize the reaction of mammalian (rat) retinal macroglia (Müller cells and astrocytes) to disturbances of their environment in the form of intraorbital section of the optic nerve, intraocular insertion of a thin glass capillary (without damage to the retina) or a combination of both. Glial reactivity was assessed through the use of a battery of antibodies which recognise four different proteins--glial fibrillary protein (GFAP) and three other proteins designated respectively MA1, 4D6 and 4H11. Retinal astrocytes did not exhibit any changes in normally expressed GFAP or MA1. By contrast, the expression of GFAP and MA1 in Müller cells increased 14 days following section of the optic nerve and/or intravitreal insertions of a glass capillary. Three days postoperatively, the expression of GFAP, but not MA1, had already increased significantly in Müller cells. 4D6 and 4H11 proteins were not expressed in astrocytes. In Müller cells, the levels of these proteins increased significantly following combined optic nerve section and intraocular insertion of a glass capillary. Thus, a mechanical disturbance of the intraocular environment constitutes a more effective stimulus in increasing the expression of some Müllerian proteins than damage to the axons of retinal ganglion cells. Such changes have important implications for various ocular treatments that involve intraocular administration of drugs, as well as for the survival/regeneration potential of retinal ganglion cells undergoing Wallerian degeneration.
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Affiliation(s)
- K R Huxlin
- Department of Physiology, University of Sydney, N.S.W., Australia
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Rich KA, Figueroa SL, Zhan Y, Blanks JC. Effects of Müller cell disruption on mouse photoreceptor cell development. Exp Eye Res 1995; 61:235-48. [PMID: 7556487 DOI: 10.1016/s0014-4835(05)80043-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Müller cells have been proposed to play an important role in photoreceptor cell development during the final stages of retinal maturation. The effect of disrupting Müller cells during mouse retinal development was investigated using the specific glial cell toxin, DL-alpha-aminoadipic acid (AAA). By giving multiple systemic injections over several days, impairment of Müller cell function was maintained during the period of photoreceptor migration and differentiation. Following three consecutive days of AAA treatment [commencing on post-natal (P) day 3, 5, 7 or 9, and examined at P8-P14], clumps of photoreceptor nuclei were displaced through the inner segments, lying immediately beneath the retinal pigment epithelium (RPE). Apart from the scalloped appearance of the outer retina, the overall lamination pattern of the retina was relatively well preserved. Even when AAA treatment commenced as early as P3, several days prior to the formation of the outer nuclear layer, the majority of photoreceptors migrated to their correct position and formed inner and outer segments. Therefore, the signals for photoreceptor migration are either provided by the Müller cells prior to P3, or, alternatively, are derived from different intrinsic or extrinsic cues. Disruption of Müller cell function was evidenced by decreased glutamine synthetase activity as well as by increased glial fibrillary acidic protein (GFAP) and decreased cellular retinaldehyde-binding protein (CRALBP) immunoreactivity. Immunocytochemistry with an antibody to CD44, which labels the microvilli of Müller cells at the outer limiting membrane, coupled with electron microscopic analysis, demonstrated that the zonulae adherentes between Müller cells and photoreceptors were either irregular or absent in areas adjacent to displaced clumps of photoreceptors. Thus AAA treatment of early post-natal mice results in localized disruption of the contacts between Müller cells and photoreceptors. These pathologic changes persist into adulthood since at P28, while short stretches of photoreceptors appeared relatively normal with fully developed outer segments, periodic clumps of displaced photoreceptor nuclei were still present adjacent to the RPE. In conclusion, Müller cell processes at the outer limiting membrane appear to play a critical role in providing a barrier to aberrant photoreceptor migration into the subretinal space.
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Affiliation(s)
- K A Rich
- Department of Pathology, University of Southern California School of Medicine, Los Angeles 90033, USA
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Oguma Y, Sawa M, Matsubayashi H, Nonaka M, Tomaru M. P element-induced mutations in Drosophila melanogaster showing high interspecific crossability between D. melanogaster females and D. simulans males. IDENGAKU ZASSHI 1995; 70:197-209. [PMID: 7605672 DOI: 10.1266/jjg.70.197] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Homozygous stocks for the second or the third chromosome of Drosophila melanogaster with a single insertional plwB element were screened for high crossability with D. simulans. Reciprocal crosses between each of these stocks and D. simulans were made, and the insemination rate at two or three days was examined. From two cycles of screening of the original 575 stocks, one stock (# 687) which showed high insemination rate was selected and was backcrossed to a w strain to substitute the background. We obtained a stock which showed 10% insemination rate with D. simulans males (control was 0%). No stocks exhibiting a high crossability with D. simulans females were acquired. Revertant strains, from which the P element had been lost, were obtained from the backcrossed # 687 stock. The insemination rates of 13 revertants to D. simulans males ranged from 1% to 33%. Seven of these 13 were not significantly different from the control line but were significantly different from the backcrossed # 687 stock. It was concluded that the mutation showing high crossability with D. simulans males was caused by the P element transposition.
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Affiliation(s)
- Y Oguma
- Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan
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27
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Sarthy V, Egal H. Transient induction of the glial intermediate filament protein gene in Müller cells in the mouse retina. DNA Cell Biol 1995; 14:313-20. [PMID: 7710688 DOI: 10.1089/dna.1995.14.313] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The glial intermediate filament protein (GFAP) gene is not normally expressed by retinal Müller cells but it is transcriptionally activated following photoreceptor degeneration. In the present study, we have examined the relationship between progressive photoreceptor loss and changes in GFAP gene activity in Müller cells. In albino mice with light-induced photoreceptor degeneration, GFAP level was strongly elevated after 2 weeks. GFAP level remained high even after 3 months in light. In situ hybridization studies showed that GFAP transcripts were quite sparse in the first week but increased dramatically after 2 weeks of light exposure. After 4 weeks in constant light, however, little GFAP mRNA was detected in Müller cells. RNA blotting also showed that there was an approximately 20-fold increase in GFAP mRNA content at 2 weeks; but at 4 weeks, the RNA content fell to about four-fold higher than the basal level. These results show that GFAP level remains high long after its synthesis, probably as a consequence of low GFAP turnover in the Müller cell cytoskeleton, while GFAP mRNA level rises and declines rapidly due to transient activation of the GFAP gene in Müller cells.
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Affiliation(s)
- V Sarthy
- Department of Ophthalmology, Cell and Molecular Biology, Northwestern University Medical School, Chicago, IL 60611, USA
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Johnson WB, Ruppe MD, Rockenstein EM, Price J, Sarthy VP, Verderber LC, Mucke L. Indicator expression directed by regulatory sequences of the glial fibrillary acidic protein (GFAP) gene: in vivo comparison of distinct GFAP-lacZ transgenes. Glia 1995; 13:174-84. [PMID: 7782103 DOI: 10.1002/glia.440130304] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An increase in the expression of the glial fibrillary acidic protein (GFAP) gene by astrocytes appears to constitute a crucial component of the brain's response to injury because it is seen in many different species and features prominently in diverse neurological diseases. Previously, we have used a modified GFAP gene (C-339) to target the expression of beta-galactosidase (beta-gal) to astrocytes in transgenic mice (Mucke et al.; New Biol 3:465-474 1991). To determine to what extent the in vivo expression of GFAP-driven fusion genes is influenced by intragenic GFAP sequences, the E. coli lacZ reporter gene was either placed downstream of approximately 2 kb of murine GFAP 5' flanking region (C-259) or ligated into exon 1 of the entire murine GFAP gene (C-445). Transgenic mice expressing C-259 versus C-445 showed similar levels and distributions of beta-gal activity in their brains. Exclusion of intragenic GFAP sequences from the GFAP-lacZ fusion gene did not diminish injury-induced upmodulation of astroglial beta-gal expression or increase beta-gal expression in non-astrocytic brain cells. These results demonstrate that 2 kb of murine GFAP 5' flanking region is sufficient to restrict transgene expression primarily to astrocytes and to mediate injury-responsiveness in vivo. This sequence therefore constitutes a critical target for mediators of reactive astrocytosis. While acute penetrating brain injuries induced focal increases in beta-gal expression around the lesion sites in C-259, C-445, and C-339 transgenic mice, infection of C-339 transgenic mice with scrapie led to a widespread upmodulation of astroglial beta-gal expression. Hence, GFAP-lacZ transgenic mice can be used to monitor differential patterns of astroglial activation in vivo. These and related models should facilitate the assessment of strategies aimed at the in vivo manipulation of GFAP expression and astroglial activation.
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Affiliation(s)
- W B Johnson
- Department of Neuropharmacology, Scripps Research Institute, La Jolla, California 92037, USA
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OGUMA Y, SAWA M, MATSUBAYASH H, NONAKA M, TOMARU M. P element-induced mutations in Drosophila melanogaster showing high interspecific crossability between D. melanogaster females and D. simulans males. Genes Genet Syst 1995. [DOI: 10.1266/ggs.70.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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Abstract
Recent experiments on the retina have examined the effectiveness of various factors (e.g. growth factors, neurotrophins and cytokines) for enhancing survival and reducing injury of retinal neurons, such as photoreceptors and ganglion cells, whose death leads to blindness in degenerative retinal diseases. It has also been shown that retinal injury stimulates intrinsic survival mechanisms that promote survival of these neurons.
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Affiliation(s)
- R H Steinberg
- Department of Physiology, University of California, San Francisco 94143-0730
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32
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Abstract
Transcriptional regulation of the GFAP gene is intimately connected with astrocyte function: its initial activation marks the differentiation of astrocytes, and its up-regulation accompanies the reactive response to CNS injury. Studies of GFAP transcription should thus provide insights into multiple regulatory pathways operating in these cells. In addition, they should identify DNA elements that could be used to direct synthesis of other proteins to astrocytes in transgenic animals, permitting creation of disease models, and the testing of cause and effect relationships. This review describes several GFAP cDNA and genomic clones that have been isolated, including homology comparisons of the encoded RNAs and proteins. Cell transfection studies by several laboratories are summarized that have identified a DNA segment immediately upstream of the RNA start site that is essential for transcriptional activity, but which have yielded conflicting results concerning the importance of other segments located both further upstream and downstream of the RNA start site. Two procedures are recounted that have led to the successful expression of GFAP-transgenes in astrocytes in mice. One of these incorporates the transgene into the first exon of a fragment spanning the entire GFAP gene, while the other links it to a 2 kb 5'-flanking segment. Results already produced by GFAP-transgenic studies include demonstration of a neurotoxic effect of the HIV-1 gp120 coat protein, and creation of a hydrocephalic mouse model.
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Affiliation(s)
- M Brenner
- Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
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33
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The rd mouse story: Seventy years of research on an animal model of inherited retinal degeneration. Prog Retin Eye Res 1994. [DOI: 10.1016/1350-9462(94)90004-3] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Humphrey MF, Constable IJ, Chu Y, Wiffen S. A quantitative study of the lateral spread of Müller cell responses to retinal lesions in the rabbit. J Comp Neurol 1993; 334:545-58. [PMID: 8408765 DOI: 10.1002/cne.903340404] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A wide variety of retinal pathology is associated with an increase in Müller glial cell expression of glial fibrillary acidic protein (GFAP). In this study the time course and spatial spread of the Müller cell GFAP response following argon laser photocoagulation lesions was examined in wholemounted rabbit retina. At 24 hours single focal lesions were surrounded by GFAP positive Müller cell end feet which declined in density with distance but extended as far as 2-3 mm from the lesion. The Müller cell reaction reached a maximal spread of 4-5 mm at 14 to 21 days and had started to contract by 30 days, leaving a core of GFAP positive processes immediately around the lesion site at 60 days. This zone of spread was much larger than the area of disrupted pigment epithelium. Isodensity plots did not reveal any correlation with the trajectory of retinal ganglion cell axons. The spread of reaction was more confined for lesions within the visual streak than in the dorsal or ventral retinal periphery. Multiple lesions within a focal region of retina resulted in a greater density of GFAP reactive end feet with a corresponding greater spread. However, when five to ten lesions were made in a horizontal row, the Müller cells over the entire retina became GFAP immunoreactive. This pan-retinal reaction took several days to spread, peaked at 7-14 days, and contracted back to the primary lesion sites by 2 months. This spread of Müller cell reactivity may be triggered by the diffusion of substances released by injury or it may be due to direct cellular communication. The extensive indirect effect on Müller cells of laser irradiation might be an important component of the clinical effect of laser photocoagulation and indicates a long distance communication mechanism between retinal glia which is poorly understood. This study also shows the importance of the time at which the Müller cell response is assessed.
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Affiliation(s)
- M F Humphrey
- Western Australian Retinitis Pigmentosa Research Centre, Nedlands
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Edward DP, Lim K, Sawaguchi S, Tso MO. An immunohistochemical study of opsin in photoreceptor cells following light-induced retinal degeneration in the rat. Graefes Arch Clin Exp Ophthalmol 1993; 231:289-94. [PMID: 8319919 DOI: 10.1007/bf00919107] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Light-induced retinal degeneration has been hypothesized to be rhodopsin-mediated. However, the alterations induced in the opsin moiety of the rhodopsin molecule and its distribution in the rod cell after a photic insult have not been definitively established. We used light and electron immunohistochemistry to study the alterations in retinal opsin immunoreactivity in a rat model of retinal photic injury. In normal unexposed rat retinas, opsin immunoreactivity was restricted to the rod outer segments. At 6 h after a 24-h light exposure, opsin immunoreactivity was present in the rod outer segments in both the superior and inferior retina, but in addition marked immunoreactivity was present in the inner segments in the superior quadrant of the light-damaged retina. At 6 days after exposure, intense immunoreactivity was noted around the severely degenerating rod nuclei and inner segments. However, at 21 days following light exposure, opsin immunoreactivity in areas of recovery was again restricted to the short regenerated rod outer segments. It appears that, despite severe light-mediated retinal degeneration, anti-opsin immunoreactivity persisted in the photoreceptor cells but with an altered pattern in damaged rod outer segments and photoreceptor perikarya. However, opsin immunoreactivity relocated to the regenerated rod outer segments in the recovery phase.
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Affiliation(s)
- D P Edward
- Georgiana Dvorak Theobald Ophthalmic Pathology Laboratory, Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago College of Medicine 60612
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Landers RA, Hollyfield JG. Proteoglycans in the mouse interphotoreceptor matrix. VI. Evidence for photoreceptor synthesis of chondroitin sulfate proteoglycan using genetically fractionated retinas. Exp Eye Res 1992; 55:345-56. [PMID: 1426067 DOI: 10.1016/0014-4835(92)90199-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To determine the role of photoreceptors in the synthesis of chondroitin sulfate proteoglycan (CS-PG) present in the interphotoreceptor matrix (IPM), 35SO4(2-) was used as a tracer for comparison of proteoglycans synthesized in vitro in the absence of the pigment epithelium by normal retinas and retinas from retinal degeneration (rd) mice at stages before and after photoreceptor degeneration. Isolated retinas from 10 day post-partum (P-10) pups, adult normal mice (C57BL/6J ++/++) and retinal degeneration mice (C57BL/6J rdle/rdle) were incubated for 7 hr with 35SO4(2-) to label newly synthesized sulfated proteoglycans. At P-10, rd retinas have not undergone extensive photoreceptor degeneration, whereas in the adult retinas from this strain, only a few cone photoreceptors remain. At the termination of the labeling period, proteoglycans in the incubation medium and those remaining in guanidine hydrochloride (GuHCl) extracts of the retina were analysed separately and identified by their susceptibility to enzymatic or nitrous acid depolymerization. At P-10, no significant differences were observed in the types or sizes of newly synthesized proteoglycan in normal and rd retinas. Medium samples from P-10 retinas contained near equal amounts of 35S-labeled CS-PG and heparan sulfate proteoglycan (HS-PG), while in GuHCl extracts, approximately 90% of the 35SO4(2-) was incorporated into HS-PG, with the remainder found in CS-PG. Comparisons of adult tissue revealed a divergence of proteoglycan synthesis profiles. Retinas from normal adults label predominantly CS-PG. [35S]proteoglycan from normal retina incubation medium was approximately 96% CS-PG, and GuHCl extracts were about 73% CS-PG. From adult rd retinas these values were 18 and 10%, respectively. Per retina, this shows the rd retinas labeling less than 4% of the medium CS-PG, and about 50% of the GuHCl extractable CS-PG compared to normal retinas. Labeled HS-PG comprised about 28% of the normal retina GuHCl extracts, but was not detected in the incubation medium. In contrast, HS-PG synthesis accounted for about 76% of the medium proteoglycan label, and about 85% of the extracted proteoglycan in the adult rd retina. In fact, 35SO4(2-) labeling of HS-PG in the rd retina GuHCl extracts exceeded by 1000% the level observed in normal retina extracts on a per retina basis. Retinas from both strains incorporate significant amounts of 35SO4(2-) into proteins with rd achieving higher specific activity. IRBP was identified as a 35SO4(2-) labeled protein by immunoadsorption from aliquots of the incubation medium.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- R A Landers
- Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030
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Erickson PA, Feinstein SC, Lewis GP, Fisher SK. Glial fibrillary acidic protein and its mRNA: ultrastructural detection and determination of changes after CNS injury. J Struct Biol 1992; 108:148-61. [PMID: 1486005 DOI: 10.1016/1047-8477(92)90014-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have previously demonstrated that glial fibrillary acidic protein (GFAP) containing intermediate filaments in retinal Müller cells undergo both quantitative induction and subcellular reorganization as a response to long-term retinal detachment (an induced CNS degeneration wherein the Müller cells form a multicellular scar). This study demonstrates by RNA blotting analysis that normal retina expresses a low basal level of GFAP mRNA, which is induced approximately 500% within 3 days of retinal detachment. At the cellular level, electron microscopic in situ hybridization analysis readily detects GFAP mRNA in Müller cells of detached retinas, but not in normal retinas. On the other hand, GFAP mRNA was readily detected in retinal astrocytes (which appear to express GFAP mRNA at high, constitutive levels). In both cell types, the ultrastructural localization of GFAP mRNA was the same. In the nuclei, the GFAP mRNA was associated with amorphous, electron-dense regions within the euchromatin. In the cytoplasm, the GFAP mRNA was associated with intermediate filaments near the nuclear pores, along the filaments when no other structures were apparent, and when the filaments appeared to be associated with ribosomes and polysomes. The ultrastructural location of the GFAP mRNA (especially along the intermediate filaments) may be unique to this mRNA or may represent a more generalized mRNA phenomenon.
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Affiliation(s)
- P A Erickson
- Neuroscience Research Institute, University of California, Santa Barbara 93106
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Fukuyama R, Fushiki S, Fujita S. Purification of glial fibrillary acidic protein (GFAP) from normal bovine brain. J Neurosci Methods 1991; 40:133-7. [PMID: 1800850 DOI: 10.1016/0165-0270(91)90062-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Glial fibrillary acidic protein (GFAP) was purified from normal bovine brain by a modification of the procedure used to isolate vimentin in order to avoid contamination by other cytoskeletal components: vimentin, neurofilament triplet proteins, tubulin and actin. GFAP is thought to be separated from vimentin in the DE cellulose column chromatography step. The three other major proteins were also separable through ion exchange and gel filtration column chromatographies. A purified 49 kDa polypeptide was estimated to be GFAP from peptide mapping and subsequent immunoblotting analysis. We obtained 4.4 mg GFAP/1 g bovine brain white matter in less than 3 days. The polyclonal antibody raised against purified GFAP was able to detect 49 kDa GFAP by immunoblotting analysis. This isolation method is simpler and more rapid than previous methods.
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Affiliation(s)
- R Fukuyama
- Department of Pathology, Kyoto Prefectural University of Medicine, Japan
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Sarthy PV, Fu M, Huang J. Developmental expression of the glial fibrillary acidic protein (GFAP) gene in the mouse retina. Cell Mol Neurobiol 1991; 11:623-37. [PMID: 1723659 DOI: 10.1007/bf00741450] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. In the nervous system, Glial fibrillary acidic protein (GFAP) is a well-known, cell type-specific marker for astrocytes. 2. In the mammalian retina, Muller cells, the major class of retinal glia, do not express GFAP or contain only low amounts of this protein. In retinas with photoreceptor degeneration, however, high levels of GFAP are found. It is possible that GFAP synthesis in these retinas could result from "dedifferentiation" of Muller cells as a consequence of disruption of normal neuron-glia interactions. 3. We have carried out immunocytochemical and in situ hybridization studies to examine whether GFAP or its mRNA is expressed by retinal cells early in embryonic development. 4. Our results show that GFAP-containing cells, which are probably astrocytes, are found only in the ganglion cell and nerve fiber layers and that these cells appear after postnatal day-1 (P-1) and continue to form until P-10. 5. Astrocyte formation starts from the optic disc and moves toward the periphery of the retina at a rate of approximately 160-200 microns per day. 6. An unexpected result from these studies is that GFAP mRNA levels are high in the first week of birth and decline rapidly as the animal develops. 7. Finally, we did not find either GFAP or GFAP mRNA in retinal cells other than astrocytes during normal development.
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Affiliation(s)
- P V Sarthy
- Department of Ophthalmology, University of Washington, Seattle 98195
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40
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Scherer J, Schnitzer J. Intraorbital transection of the rabbit optic nerve: consequences for ganglion cells and neuroglia in the retina. J Comp Neurol 1991; 312:175-92. [PMID: 1748726 DOI: 10.1002/cne.903120202] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rabbit retinae were stained with antibodies to glial fibrillary acidic protein (GFAP) at various times up to 5 months after complete unilateral intraorbital optic nerve transection, which is known to induce degeneration of ganglion cell axons and perikarya in the retina. A transient immunoreactivity for GFAP was observed in Müller glial cells that normally lack this marker. Müller-cell GFAP immunoreactivity became detectable 4 days after the lesion, but Müller cells were no longer labeled 3 months later. GFAP-labeled astrocytes located in the nerve fiber layer showed no change in immunoreactivity at any stage after transection. Application of horseradish peroxidase to the left and right superior colliculus of a rabbit whose optic nerve had been transected unilaterally 2 years before confirmed the completeness of the transection. Yet electron microscopy showed the presence of some healthy-looking ganglion cell axons in the lesioned retina, although these cells were deprived of their target. Labeling retinal wholemounts with neurofilament antibodies confirmed the presence of some ganglion cell axons and perikarya in the retina more than 2 years after transection. The course of these axons suggested that they were remnants of axons. Using antibodies to galactocerebroside (GC) we found that, as in the normal rabbit, these persisting ganglion cell axons were myelinated in the medullary rays. Although many ganglion cell axons had disappeared after 2 years, the number of neuroglial cells (including astrocytes and oligodendrocytes) present in the medullary ray region was not altered. The cell bodies of some oligodendrocytes were covered with a myelin sheath, an aberrant feature not seen normally.
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Affiliation(s)
- J Scherer
- Max-Planck-Institut für Hirnforschung, Abteilung Neuroanatomie, Frankfurt am Main, Federal Republic of Germany
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41
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Semple-Rowland SL. Expression of glial fibrillary acidic protein by Müller cells in rd chick retina. J Comp Neurol 1991; 305:582-90. [PMID: 2045537 DOI: 10.1002/cne.903050405] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Accumulation of glial fibrillary acidic protein (GFAP) in Müller cells has been observed in retinas of several mammalian species secondary to genetically induced degeneration and neuronal injury. In the present series of experiments, I have examined the effects of the rd (retinal degeneration) mutation on the expression of GFAP in retinas of chicks homozygous for the mutation (rd/rd) prior to and following the onset of photoreceptor degeneration, which first appears approximately 7 days posthatch (7 dph). Carrier (+/rd) and wild-type (+/+) retinas served as controls. Retinas taken from 1, 7, 21, and 33 dph rd/rd, +/rd, and +/+ chicks were analyzed for the presence of GFAP by immunocytochemical and SDS-PAGE/Western blot techniques. The following immunocytochemical observations were made: (1) GFAP immunostaining was limited to and located throughout the Müller cells. (2) The intensity of GFAP immunostaining increased with age in all three retina types in tissue sections, as well as on immunoblots. (3) The distribution of GFAP staining within rd/rd Müller cells following the onset of degeneration was slightly different from that observed in +/+ and +/rd retinas and was distinguished by increased staining of the cell bodies and the cell processes forming the outer limiting membrane. The results of these experiments show that Müller cells in chick retina contain GFAP. In addition, they suggest that, in contrast to Müller cells in degenerating mammalian retina, Müller cells in rd chick retina do not accumulate large amounts of GFAP in response to degeneration.
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Affiliation(s)
- S L Semple-Rowland
- Department of Neuroscience, University of Florida College of Medicine, Gainesville 32610-0244
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Cuthbertson RA, Lang RA, Coghlan JP. Macrophage products IL-1 alpha, TNF alpha and bFGF may mediate multiple cytopathic effects in the developing eyes of GM-CSF transgenic mice. Exp Eye Res 1990; 51:335-44. [PMID: 2205511 DOI: 10.1016/0014-4835(90)90030-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
GM-CSF transgenic mice develop eye disease during ontogeny that is mediated by autostimulated macrophages. The ocular pathology is characterized in part by corneal and vitreous neovascularization, pronounced GFAP expression by retinal Müller cells and degeneration of the retinal photoreceptor layer. The invading intraocular macrophages express the genes for the cytokines interleukin-1 alpha, tumor necrosis factor alpha and basic fibroblast growth factor, which may contribute to the multifaceted developmental ocular disorder. These cytokines, suspected to be angiogenic, may be responsible for neovascularization of the cornea in our transgenic animals. GFAP is normally made by astrocytes in the superficial retina and is induced in Müller cells in models of retinal degeneration. This protein is abnormally and copiously produced by Müller cells in the transgenic mice, which we suggest may be due to the release of cytokines from the invading macrophages. We suggest a mechanism by which autostimulated macrophages, through a perturbation of their normal developmental role, may be responsible for photoreceptor cell death in these transgenic animals.
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Affiliation(s)
- R A Cuthbertson
- Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria, Australia
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Abstract
In the nervous system, neuronal migration and axonal growth are dependent on specific interactions with extracellular matrix proteins. During development of the vertebrate retina, ganglion cell axons extend along the internal limiting (basement) membrane and form the optic nerve. Laminin, a major component of basement membranes, is known to be present in the internal limiting membrane, and might be involved in the growth of ganglion cell axons. The identity of the cells that produce retinal laminin, however, has not been established. In the present study, we have used in situ hybridization to localize the sites of laminin B1 mRNA synthesis in the developing mouse retina. Our results show that there are at least two principal sites of laminin B1 mRNA synthesis: (a) the hyaloid vessels and the lens during the period of major axonal outgrowth, and (b) the retinal ganglion cells at later development stages. Müller (glial) cells, the major class of nonneuronal cells in the retina, do not appear to express laminin B1 mRNA either during development or in the adult retina. In Northern blots, we found a single transcript of approximately 6-kb size that encodes the laminin B1 chain in the retina. Moreover, laminin B1 mRNA level was four- to fivefold higher in the postnatal retina compared to that in the adult. Our results show that in addition to nonneuronal cells, retinal ganglion cells also synthesize laminin. The function of laminin in postnatal retinas, however, remains to be elucidated. Nevertheless, our findings raise the possibility that neurons in other parts of the nervous system might also synthesize extracellular matrix proteins.
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Affiliation(s)
- P V Sarthy
- Department of Ophthalmology, University of Washington, Seattle 98195
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44
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Burns MS, Robles M. Müller cell GFAP expression exhibits gradient from focus of photoreceptor light damage. Curr Eye Res 1990; 9:479-86. [PMID: 2200639 DOI: 10.3109/02713689008999613] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
High intensity (ca. 150 foot-candles), cumulative fluorescent light exposure regimes of 40 or 60 minutes to pigmented Long Evans rats were sufficient to elicit glial fibrillary acidic protein immunoreactivity (GFAP-IR) in Müller cells, when the animals are sacrificed 7 days post-exposure. Exposure to only 20 minutes of cumulative light or sacrifice immediately after exposure was not sufficient to initiate GFAP-IR in Müller cells. A gradient of GFAP-IR was observed extending from an approximately circular focus superior to the optic disc to the peripheral retina, whether or not there was morphological damage to the photoreceptors observable at the light microscopic level. Photoreceptor lesions produced by laser photocoagulation elicited the same gradient of GFAP-IR, and showed that GFAP-IR was not a reflection of a central to peripheral gradient of light received by the retina. Excessive light exposure initiated a signal which induced GFAP expression in Müller cells. This signal appeared to require a dark period and may be a diffusible factor that moves through extracellular pathways.
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Affiliation(s)
- M S Burns
- Department of Ophthalmology, School of Medicine, University of California, Davis
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45
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Subcellular localization of an intermediate filament protein and its mRNA in glial cells. Mol Cell Biol 1989. [PMID: 2586519 DOI: 10.1128/mcb.9.10.4556] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eucaryotic mRNAs are generally localized in the cell body, where most protein synthesis occurs. We have found that mRNAs encoding the glial intermediate filament protein are spatially distributed in the glial cell cytoplasm close to the location of the glial filaments. Whereas the glial filament protein mRNA was located predominantly in the distal process, actin mRNA was found almost exclusively in the apical portion of the glial cell. This pattern of mRNA localization might provide a mechanism for synthesis of proteins in specific subcellular compartments by mRNA translation locally.
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46
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Sarthy PV, Fu M, Huang J. Subcellular localization of an intermediate filament protein and its mRNA in glial cells. Mol Cell Biol 1989; 9:4556-9. [PMID: 2586519 PMCID: PMC362543 DOI: 10.1128/mcb.9.10.4556-4559.1989] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Eucaryotic mRNAs are generally localized in the cell body, where most protein synthesis occurs. We have found that mRNAs encoding the glial intermediate filament protein are spatially distributed in the glial cell cytoplasm close to the location of the glial filaments. Whereas the glial filament protein mRNA was located predominantly in the distal process, actin mRNA was found almost exclusively in the apical portion of the glial cell. This pattern of mRNA localization might provide a mechanism for synthesis of proteins in specific subcellular compartments by mRNA translation locally.
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Affiliation(s)
- P V Sarthy
- Department of Ophthalmology, Physiology and Biophysics, University of Washington, Seattle 98195
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