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Sen A, Desai J, Sharma S, Thounaojam S, Kala U, Majumdar B, Pradhan A, Chowdhury R, Chattree S, Saurabh K, Roy R. Hyperreflective Ganglion Cell Layer Band in Gyrate Atrophy. Ophthalmic Surg Lasers Imaging Retina 2024:1-5. [PMID: 39037355 DOI: 10.3928/23258160-20240528-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
We have described the hyperreflective ganglion cell layer band (HGCB) in a series of cases of gyrate atrophy. Clinical fundus examination and multimodal imaging which included optical coherence tomography (OCT) was done in all cases. Four patients (one male, three female) were studied. In all four cases, a hyperreflective band was noted in the ganglion cell layer. In three patients, the band was continuous, and in one patient, the band was patchy. To conclude, HGCB is a novel OCT sign in gyrate atrophy and can be valuable in prognostication of disease. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].
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Pauleikhoff L, Weisschuh N, Lentzsch A, Spital G, Krohne TU, Agostini H, Lange CAK. Clinical characteristics of gyrate atrophy compared with a gyrate atrophy-like retinal phenotype. Eur J Ophthalmol 2024; 34:79-88. [PMID: 37218157 DOI: 10.1177/11206721231178147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
INTRODUCTION Gyrate atrophy (GA) is a rare retinal dystrophy due to biallelic pathogenic variants in the ornithine aminotransferase (OAT) gene, causing a 10-fold increase in plasma ornithine levels. It is characterized by circular patches of chorioretinal atrophy. However, a GA-like retinal phenotype (GALRP) without elevated ornithine levels has also been reported. The aim of this study is to compare the clinical characteristics of GA and GALRP and to identify possible discriminators. METHODS A multicenter, retrospective chart review was performed at three German referral centres on patient records between 01/01/2009 and 31/12/2021. Records were screened for patients affected by GA or GALRP. Only patients with examination results for plasma ornithine levels and / or genetic testing of the OAT gene were included. Further clinical data was gathered where available. RESULTS Ten patients (5 female) were included in the analysis. Three suffered from GA, while seven had a GALRP. Mean age (± SD) at onset of symptoms was 12.3 (± 3.5) years for GA compared with 46.7 (± 14.0) years for GALRP patients (p = 0.002). Mean degree of myopia was higher in GA (-8.0 dpt. ± 3.6) compared to GALRP patients (-3.8 dpt. ± 4.8, p = 0.04). Interestingly, all GA patients showed macular oedema, while only one GALRP patient did. Only one patient with GALRP had a positive family history, while two were immunosuppressed. DISCUSSION Age of onset, refraction and presence of macular cystoid cavities appear to be discriminators between GA and GALRP. GALRP may encompass both genetic and non-genetic subtypes.
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Affiliation(s)
- L Pauleikhoff
- Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Ophthalmology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - N Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - A Lentzsch
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - G Spital
- St. Franziskus Eye Center, Münster, Germany
| | - T U Krohne
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - H Agostini
- Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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da Palma MM, Ku C, Igelman AD, Burr A, Shevchenko Sutherland L, Koerner C, Valle D, Pennesi ME, Yang P. A possible ocular biomarker for response to hyperornithinemia in gyrate atrophy: the effect of pyridoxine, lysine, and arginine-restricted diet in a patient with advanced disease. Ophthalmic Genet 2023; 44:191-197. [PMID: 35856163 DOI: 10.1080/13816810.2022.2098986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND Loss of function variants in the ornithine aminotransferase (OAT) gene cause accumulation of ornithine levels, leading to gyrate atrophy. The benefit of ornithine-lowering therapies has been documented in a mouse model and young patients, however, the effect in adults with advanced disease has not been well described. MATERIALS AND METHODS Case report of an adult patient with advanced gyrate atrophy, who underwent treatment with pyridoxine and an arginine-restricted diet for four years. RESULTS A 51-year-old female with advanced chorioretinal degeneration presented with hyperornithinemia (961 vs. normal 18-135 µmol/L) and compound heterozygous pathogenic variants in OAT (p.Tyr299* and p.Ala270Pro). Treatment with pyridoxine and arginine-diet restriction yielded a maximal reduction in ornithine levels by 71% (275 µmol/L). Optical coherence tomography (OCT) showed a reduction in ellipsoid zone (EZ) thickness that correlated with lower ornithine levels and reversed with higher ornithine levels. While her best-corrected visual acuity remained unchanged, the progressive decline in her visual fields appeared to stabilize during a one-year period when ornithine levels were below 500 µmol/L. CONCLUSIONS In this report, we demonstrate that chorioretinal degeneration appears to stabilize in an adult patient with gyrate atrophy in association with a partial reduction in ornithine levels. We also observed a correlation with reduced EZ thickness on OCT and propose this may be a novel biomarker for ornithine reduction therapies. Our case study characterizes the potential retinal structure-function benefits of ornithine-lowering treatments even in cases of advanced chorioretinal degeneration. Thus, we recommend a low threshold for treating all patients with gyrate atrophy.
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Affiliation(s)
- Mariana Matioli da Palma
- Department of Ophthalmology, Casey Eye Institute at Oregon Health & Science University (OHSU), Portland, OR, USA
- Department of Ophthalmology, Universidade Federal de São Paulo Escola Paulista de Medicina (UNIFESP), São Paulo, Brazil
| | - Cristy Ku
- Department of Ophthalmology, Casey Eye Institute at Oregon Health & Science University (OHSU), Portland, OR, USA
| | - Austin D Igelman
- Department of Ophthalmology, Casey Eye Institute at Oregon Health & Science University (OHSU), Portland, OR, USA
| | - Amanda Burr
- Department of Ophthalmology, Casey Eye Institute at Oregon Health & Science University (OHSU), Portland, OR, USA
| | | | - Celide Koerner
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine Baltimore, Maryland, USA
| | - David Valle
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine Baltimore, Maryland, USA
| | - Mark E Pennesi
- Department of Ophthalmology, Casey Eye Institute at Oregon Health & Science University (OHSU), Portland, OR, USA
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute at Oregon Health & Science University (OHSU), Portland, OR, USA
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Cellular and Molecular Mechanisms of Pathogenesis Underlying Inherited Retinal Dystrophies. Biomolecules 2023; 13:biom13020271. [PMID: 36830640 PMCID: PMC9953031 DOI: 10.3390/biom13020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/23/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) are congenital retinal degenerative diseases that have various inheritance patterns, including dominant, recessive, X-linked, and mitochondrial. These diseases are most often the result of defects in rod and/or cone photoreceptor and retinal pigment epithelium function, development, or both. The genes associated with these diseases, when mutated, produce altered protein products that have downstream effects in pathways critical to vision, including phototransduction, the visual cycle, photoreceptor development, cellular respiration, and retinal homeostasis. The aim of this manuscript is to provide a comprehensive review of the underlying molecular mechanisms of pathogenesis of IRDs by delving into many of the genes associated with IRD development, their protein products, and the pathways interrupted by genetic mutation.
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Boffa I, Polishchuk E, De Stefano L, Dell'Aquila F, Nusco E, Marrocco E, Audano M, Pedretti S, Caterino M, Bellezza I, Ruoppolo M, Mitro N, Cellini B, Auricchio A, Brunetti-Pierri N. Liver-directed gene therapy for ornithine aminotransferase deficiency. EMBO Mol Med 2023; 15:e17033. [PMID: 36647689 PMCID: PMC10086579 DOI: 10.15252/emmm.202217033] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 01/18/2023] Open
Abstract
Gyrate atrophy of choroid and retina (GACR) is a chorioretinal degeneration caused by pathogenic variants in the gene encoding ornithine aminotransferase (OAT), an enzyme mainly expressed in liver. Affected patients have increased ornithine concentrations in blood and other body fluids and develop progressive constriction of vision fields leading to blindness. Current therapies are unsatisfactory and better treatments are highly needed. In two mouse models of OAT deficiency that recapitulates biochemical and retinal changes of GACR, we investigated the efficacy of an intravenously injected serotype 8 adeno-associated (AAV8) vector expressing OAT under the control of a hepatocyte-specific promoter. Following injections, OAT-deficient mice showed reductions of ornithine concentrations in blood and eye cups compared with control mice injected with a vector expressing green fluorescent protein. AAV-injected mice showed improved electroretinogram response and partial restoration of retinal structure up to one-year post-injection. In summary, hepatic OAT expression by AAV8 vector was effective at correction of hyperornithinemia and improved function and structure of the retina. In conclusion, this study provides proof-of-concept of efficacy of liver-directed AAV-mediated gene therapy of GACR.
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Affiliation(s)
- Iolanda Boffa
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Elena Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Lucia De Stefano
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Fabio Dell'Aquila
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Edoardo Nusco
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Elena Marrocco
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Matteo Audano
- Department of Pharmacology and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Silvia Pedretti
- Department of Pharmacology and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Marianna Caterino
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy.,CEINGE - Biotecnologie Avanzate s.c.a.r.l., Naples, Italy
| | - Ilaria Bellezza
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
| | - Margherita Ruoppolo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy.,CEINGE - Biotecnologie Avanzate s.c.a.r.l., Naples, Italy
| | - Nico Mitro
- Department of Pharmacology and Biomolecular Sciences, University of Milan, Milan, Italy.,Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Barbara Cellini
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Advanced Biomedical Sciences, "Federico II" University, Naples, Italy
| | - Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Translational Medicine, "Federico II" University, Naples, Italy.,Scuola Superiore Meridionale (SSM, School of Advanced Studies), Genomics and Experimental Medicine Program, University of Naples Federico II, Naples, Italy
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Preclinical Models of Retinitis Pigmentosa. Methods Mol Biol 2022; 2560:181-215. [PMID: 36481897 DOI: 10.1007/978-1-0716-2651-1_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is the name for a group of phenotypically-related heritable retinal degenerative disorders. Many genes have been implicated as causing variants of RP, and while the clinical phenotypes are remarkably similar, they may differ in age of onset, progression, and severity. Common inheritance patterns for specific genes connected with the development of the disorder include autosomal dominant, autosomal recessive, and X-linked. Modeling the disease in animals and other preclinical systems offers a cost-conscious, ethical, and time-efficient method for studying the disease subtypes. The history of RP models is briefly examined, and both naturally occurring and transgenic preclinical models of RP in many different organisms are discussed. Syndromic forms of RP and models thereof are reviewed as well.
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Maldonado R, Jalil S, Keskinen T, Nieminen AI, Hyvönen ME, Lapatto R, Wartiovaara K. CRISPR correction of the Finnish ornithine delta-aminotransferase mutation restores metabolic homeostasis in iPSC from patients with gyrate atrophy. Mol Genet Metab Rep 2022; 31:100863. [PMID: 35782600 PMCID: PMC9248217 DOI: 10.1016/j.ymgmr.2022.100863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 03/18/2022] [Indexed: 11/26/2022] Open
Abstract
Hyperornithinemia with gyrate atrophy of the choroid and retina (HOGA) is a severe recessive inherited disease, causing muscular degeneration and retinochoroidal atrophy that progresses to blindness. HOGA arises from mutations in the ornithine aminotransferase (OAT) gene, and nearly one-third of the known patients worldwide are homozygous for the Finnish founder mutation OAT c.1205 T > C p.(Leu402Pro). We have corrected this loss-of-function OAT mutation in patient-derived induced pluripotent stem cells (iPSCs) using CRISPR/Cas9. The correction restored OAT expression in stem cells and normalized the elevated ornithine levels in cell lysates and cell media. These results show an efficient recovery of OAT function in iPSC, encouraging the possibility of autologous cell therapy for the HOGA disease.
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Affiliation(s)
- Rocio Maldonado
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Sami Jalil
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Timo Keskinen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anni I. Nieminen
- Metabolomics Unit, Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Mervi E. Hyvönen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Risto Lapatto
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Kirmo Wartiovaara
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Clinical Genetics, Helsinki University Hospital, Helsinki, Finland
- Corresponding author at: Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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Nitta K, Mukai R, Akiyama H. Obscured interdigitation zone at the early stage of gyrate atrophy: A case report. Am J Ophthalmol Case Rep 2022; 25:101277. [PMID: 35112019 PMCID: PMC8790631 DOI: 10.1016/j.ajoc.2022.101277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/22/2021] [Accepted: 01/13/2022] [Indexed: 11/28/2022] Open
Abstract
Purpose To report an early stage of gyrate atrophy (GA) of the retina and choroid for which spectral-domain optical coherence tomography (SD-OCT) images revealed an obscured interdigitation zone (IZ). Observation A 13-year-old boy was referred to our department due to blurred vision in his left eye. Best corrected visual acuity was 20/20 and 20/25 in the right and left eye, respectively. Fundus examination revealed scalloped atrophic peripheral chorioretinal lesions in both eyes. Concentrations of plasma and urine ornithine were 1192 nmol/mL and 1930 μmol/g·cre, respectively. Consequently, he was diagnosed with GA. Although Goldmann perimetry found no abnormalities, electroretinogram (ERG) revealed loss of the rod responses and significant attenuation of the cone responses in both eyes. Detailed analysis of the posterior part of the fundus using multifocal electroretinogram showed poor responses, specifically in the nasal macular area of the left eye. SD-OCT showed an obscured IZ corresponding to the attenuated cone response determined by ERG. There was preservation of the retinal pigment epithelium, ellipsoid zone and external limiting membrane. Conclusions and Importance Obscured IZ during early stage GA was confirmed in a teenage patient with a chief complaint of blurred vision. OCT is useful in the detection of minute morphological changes that occur earlier in GA.
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9
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Abstract
Gyrate atrophy (GA) of the choroid and retina is a rare autosomal recessive genetic condition characterized by elevation of the plasma level of the amino acid ornithine due to deficiency of the enzyme ornithine ketoacid aminotransferase. Accumulation of ornithine occurs in various body tissues but leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes. Patients usually present with night blindness that starts in the first decade of life followed by visual field constriction and eventually diminution of the central visual acuity and blindness. The condition has been reported worldwide and its differential diagnosis is broad and includes choroideremia and retinitis pigmentosa. Treatment currently depends on life-long dietary modifications including restriction of the amino acid arginine in diet. This article describes in detail the pathogenesis, clinical features, multimodal imaging findings, and treatment options for GA of the choroid and retina and its complications.
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Affiliation(s)
- Ayman G Elnahry
- Department of Ophthalmology, Faculty of Medicine, 63526Cairo University, Cairo, Egypt
| | - Gehad A Elnahry
- Department of Ophthalmology, Faculty of Medicine, 63526Cairo University, Cairo, Egypt
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Oh JK, Lima de Carvalho JR, Nuzbrokh Y, Ryu J, Chemudupati T, Mahajan VB, Sparrow JR, Tsang SH. Retinal Manifestations of Mitochondrial Oxidative Phosphorylation Disorders. Invest Ophthalmol Vis Sci 2021; 61:12. [PMID: 33049060 PMCID: PMC7571321 DOI: 10.1167/iovs.61.12.12] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose The purpose of this paper was to discuss manifestations of primary mitochondrial dysfunctions and whether the retinal pigment epithelium or the photoreceptors are preferentially affected. Methods A retrospective analysis was performed of patients with clinically and laboratory confirmed diagnoses of maternally inherited diabetes and deafness (MIDD) or Kearns–Sayre syndrome (KSS). Patients underwent full ophthalmic examination, full-field electroretinogram, and multimodal imaging studies, including short-wavelength autofluorescence, spectral domain-optical coherence tomography, and color fundus photography. Results A total of five patients with MIDD and four patients with KSS were evaluated at two tertiary referral centers. Mean age at initial evaluation was 50.3 years old. Nascent outer retinal tubulations corresponding with faint foci of autofluorescence were observed in two patients with MIDD. Characteristic features of this cohort included a foveal sparing phenotype observed in 13 of 18 eyes (72%), global absence of intraretinal pigment migration, and preserved retinal function on full-field electroretinogram testing in 12 of 16 eyes (75%). One patient diagnosed with MIDD presented with an unusual pattern of atrophy surrounding the parapapillary region and one patient with KSS presented with an atypical choroideremia-like phenotype. Conclusions MIDD and KSS are phenotypically heterogeneous disorders. Several features of disease suggest that primary mitochondrial dysfunction may first affect the retinal pigment epithelium followed by secondary photoreceptor loss. Similarities between primary mitochondrial degenerations and retinal disorders, such as age-related macular degeneration may suggest a primary role of mitochondria in the pathogenesis of these oligogenic disorders.
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Affiliation(s)
- Jin Kyun Oh
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,State University of New York at Downstate Medical Center, Brooklyn, New York, United States
| | - Jose Ronaldo Lima de Carvalho
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Department of Ophthalmology, Empresa Brasileira de Servicos Hospitalares (EBSERH) - Hospital das Clinicas de Pernambuco (HCPE), Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil.,Department of Ophthalmology, Federal University of São Paulo (UNIFESP), São Paulo, São Paulo, Brazil
| | - Yan Nuzbrokh
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Renaissance School of Medicine at Stony Brook University, Stony Brook, New York, United States
| | - Joseph Ryu
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States
| | - Teja Chemudupati
- Molecular Surgery Laboratory, Byers Eye Institute, Stanford University, Palo Alto, California, United States
| | - Vinit B Mahajan
- Molecular Surgery Laboratory, Byers Eye Institute, Stanford University, Palo Alto, California, United States.,Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States
| | - Janet R Sparrow
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Department of Pathology and Cell Biology and Columbia Stem Cell Initiative (CSCI), Columbia University Irving Medical Center, New York, New York, United States
| | - Stephen H Tsang
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Department of Pathology and Cell Biology and Columbia Stem Cell Initiative (CSCI), Columbia University Irving Medical Center, New York, New York, United States
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Montioli R, Bellezza I, Desbats MA, Borri Voltattorni C, Salviati L, Cellini B. Deficit of human ornithine aminotransferase in gyrate atrophy: Molecular, cellular, and clinical aspects. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1869:140555. [PMID: 33068755 DOI: 10.1016/j.bbapap.2020.140555] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023]
Abstract
Gyrate Atrophy (GA) of the choroid and retina (MIM# 258870) is an autosomal recessive disorder due to mutations of the OAT gene encoding ornithine-delta-aminotransferase (OAT), associated with progressive retinal deterioration and blindness. The disease has a theoretical global incidence of approximately 1:1,500,000. OAT is mainly involved in ornithine catabolism in adults, thus explaining the hyperornithinemia as hallmark of the disease. Patients are treated with an arginine-restricted diet, to limit ornithine load, or the administration of Vitamin B6, a precursor of the OAT coenzyme pyridoxal phosphate. Although the clinical and genetic aspects of GA are known for many years, the enzymatic phenotype of pathogenic variants and their response to Vitamin B6, as well as the molecular mechanisms explaining retinal damage, are poorly clarified. Herein, we provide an overview of the current knowledge on the biochemical properties of human OAT and on the molecular, cellular, and clinical aspects of GA.
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Affiliation(s)
- Riccardo Montioli
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | - Ilaria Bellezza
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
| | - Maria Andrea Desbats
- Clinical Genetics Unit, Department of Woman and Child Health, University of Padova, Padova, Italy
| | - Carla Borri Voltattorni
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Woman and Child Health, University of Padova, Padova, Italy.
| | - Barbara Cellini
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy.
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Mansour AM, Elnahry AG, Tripathy K, Foster RE, Mehanna CJ, Vishal R, Çavdarlı C, Arrigo A, Parodi MB. Analysis of optical coherence angiography in cystoid macular oedema associated with gyrate atrophy. Eye (Lond) 2020; 35:1766-1774. [PMID: 32873946 DOI: 10.1038/s41433-020-01166-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/14/2020] [Accepted: 08/21/2020] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND To evaluate the relationship between superficial, deep foveal avascular zone (FAZ) and foveal cyst areas in eyes with cystoid macular oedema (CMO) associated with gyrate atrophy of the choroid and retina (GA). METHODS This is a retrospective collaborative multicenter study of optical coherence tomography-angiography (OCTA) images in GA. Superficial and deep FAZ and foveal cyst were measured using Image J by two independent experts. Values were corrected for myopia magnification. These values were compared with age-matched controls from normative data. RESULTS Twenty-three eyes from 12 patients with GA and CMO were included in the study. The mean ± standard deviation age was 22 ± 19.7 years, mean Snellen spectacle-corrected visual acuity of 20/70 with mean myopia of 5.7 ± 4.1 dioptres. Qualitatively, no focal occlusion of superficial and deep capillary plexus was noted. Mean superficial FAZ area (0.484 ± 0.317 mm2), deep FAZ area (0.626 ± 0.452 mm2), and foveal cyst area (0.630 ± 0.503 mm2) were significantly larger than superficial and deep FAZ areas in controls of same age range (p < 0.001). Macular cyst area correlated with superficial FAZ area (R = 0.59; p = 0.0057) and more strongly with deep FAZ area (R = 0.69; p < 0.001). CONCLUSIONS The superficial and deep FAZ area in GA-associated CMO were noted to be significantly larger than in controls. It seems that RPE dysfunction leads to foveal cyst enlargement displacing the capillary plexus with resultant enlarged superficial and deep FAZ area.
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Affiliation(s)
- Ahmad M Mansour
- Department of Ophthalmology, American University of Beirut, Beirut, Lebanon. .,Department of Ophthalmology, Rafic Hariri University Hospital, Beirut, Lebanon.
| | - Ayman G Elnahry
- Department of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Koushik Tripathy
- Department of Ophthalmology, Department of Retina and Uvea, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.,Department of Vitreoretina and Uvea, ASG Eye Hospital, 149 BT Road, Near Kamarhati More, Kolkata, India
| | - Robert E Foster
- Department of Ophthalmology, University of Cincinnati, CIncinnati Eye Institute, Cincinnati, OH, USA
| | - Carl-Jo Mehanna
- Department of Ophthalmology, American University of Beirut, Beirut, Lebanon
| | - Raval Vishal
- L.V. Prasad Eye Institute, Kode Venkatadri Chowdary Campus, Tadigadapa, India
| | - Cemal Çavdarlı
- Department of Ophthalmology, Ankara City Hospital, MHC Blok Bilent University, Ankara, Turkey
| | - Alessandro Arrigo
- Department of Ophthalmology Ospedale San Raffaele, University Vita-Salute Milan, Milano, Italy.,Department of Biomedical sciences and morphological and functional imaging, University of Messina, Messina, Italy
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Yam M, Engel AL, Wang Y, Zhu S, Hauer A, Zhang R, Lohner D, Huang J, Dinterman M, Zhao C, Chao JR, Du J. Proline mediates metabolic communication between retinal pigment epithelial cells and the retina. J Biol Chem 2019; 294:10278-10289. [PMID: 31110046 PMCID: PMC6664195 DOI: 10.1074/jbc.ra119.007983] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/16/2019] [Indexed: 01/16/2023] Open
Abstract
The retinal pigment epithelium (RPE) is a monolayer of pigmented cells between the choroid and the retina. RPE dysfunction underlies many retinal degenerative diseases, including age-related macular degeneration, the leading cause of age-related blindness. To perform its various functions in nutrient transport, phagocytosis of the outer segment, and cytokine secretion, the RPE relies on an active energy metabolism. We previously reported that human RPE cells prefer proline as a nutrient and transport proline-derived metabolites to the apical, or retinal, side. In this study, we investigated how RPE utilizes proline in vivo and why proline is a preferred substrate. By using [13C]proline labeling both ex vivo and in vivo, we found that the retina rarely uses proline directly, whereas the RPE utilizes it at a high rate, exporting proline-derived mitochondrial intermediates for use by the retina. We observed that in primary human RPE cell culture, proline is the only amino acid whose uptake increases with cellular maturity. In human RPE, proline was sufficient to stimulate de novo serine synthesis, increase reductive carboxylation, and protect against oxidative damage. Blocking proline catabolism in RPE impaired glucose metabolism and GSH production. Notably, in an acute model of RPE-induced retinal degeneration, dietary proline improved visual function. In conclusion, proline is an important nutrient that supports RPE metabolism and the metabolic demand of the retina.
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Affiliation(s)
- Michelle Yam
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Abbi L Engel
- the Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | - Yekai Wang
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Siyan Zhu
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Allison Hauer
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Rui Zhang
- From the Departments of Ophthalmology and
- the Save Sight Institute, University of Sydney, 8 Macquarie Street, Sydney, New South Wales 2000, Australia
| | - Daniel Lohner
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Jiancheng Huang
- From the Departments of Ophthalmology and
- the Eye Institute, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China, and
- the Department of Ophthalmology, State Key Laboratory of Reproductive Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Marlee Dinterman
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Chen Zhao
- the Eye Institute, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China, and
| | - Jennifer R Chao
- the Department of Ophthalmology, University of Washington, Seattle, Washington 98109,
| | - Jianhai Du
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
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14
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Jasani KM, Parry NRA, Black G, Kelly SP. Unique case of gyrate atrophy with a well-preserved electroretinogram (ERG). BMJ Case Rep 2018; 2018:bcr-2016-217556. [PMID: 29437727 DOI: 10.1136/bcr-2016-217556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Gyrate atrophy is a rare autosomal recessive disorder caused by a mutation in the ornithine-δ-amino transferase gene. We present an interesting case of a 33-year-old woman who presented with increasing myopia, nyctalopia and failing vision. Examination revealed posterior subscapsular cataracts, narrowed peripheral visual fields and scalloped atrophic peripheral chorioretinal lesions. Blood investigations showed a raised plasma ornithine level at 917 μmol/L (normal range: 32-88 μmol/L) confirming the diagnosis of gyrate atrophy. The patient, despite not tolerating dietary treatment, had retained central vision over a follow-up period of 18 years. The electroretinogram, which normally diminishes with disease progression, was still nearly normal when last tested at 16 years follow-up. Genetic testing did not reveal any novel mutation that could account for this variation.
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Affiliation(s)
- Kirti M Jasani
- Department of Ophthalmology, Royal Bolton Hospital, Bolton, UK
| | - Neil R A Parry
- Vision Science Centre, Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK.,Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Graeme Black
- Vision Science Centre, Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK.,Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Simon P Kelly
- Department of Ophthalmology, Royal Bolton Hospital, Bolton, UK
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15
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Chao JR, Knight K, Engel AL, Jankowski C, Wang Y, Manson MA, Gu H, Djukovic D, Raftery D, Hurley JB, Du J. Human retinal pigment epithelial cells prefer proline as a nutrient and transport metabolic intermediates to the retinal side. J Biol Chem 2017; 292:12895-12905. [PMID: 28615447 DOI: 10.1074/jbc.m117.788422] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/30/2017] [Indexed: 11/06/2022] Open
Abstract
Metabolite transport is a major function of the retinal pigment epithelium (RPE) to support the neural retina. RPE dysfunction plays a significant role in retinal degenerative diseases. We have used mass spectrometry with 13C tracers to systematically study nutrient consumption and metabolite transport in cultured human fetal RPE. LC/MS-MS detected 120 metabolites in the medium from either the apical or basal side. Surprisingly, more proline is consumed than any other nutrient, including glucose, taurine, lipids, vitamins, or other amino acids. Besides being oxidized through the Krebs cycle, proline is used to make citrate via reductive carboxylation. Citrate, made either from 13C proline or from 13C glucose, is preferentially exported to the apical side and is taken up by the retina. In conclusion, RPE cells consume multiple nutrients, including glucose and taurine, but prefer proline, and they actively synthesize and export metabolic intermediates to the apical side to nourish the outer retina.
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Affiliation(s)
- Jennifer R Chao
- Department of Ophthalmology, University of Washington, Seattle, Washington 98109.
| | - Kaitlen Knight
- Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | - Abbi L Engel
- Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | - Connor Jankowski
- Department of Biochemistry, University of Washington, Seattle, Washington 98109
| | - Yekai Wang
- Department of Ophthalmology, West Virginia University, Morgantown, West Virginia 26506; Department of Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Megan A Manson
- Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | - Haiwei Gu
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington 98109
| | - Danijel Djukovic
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington 98109
| | - Daniel Raftery
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington 98109
| | - James B Hurley
- Department of Ophthalmology, University of Washington, Seattle, Washington 98109; Department of Biochemistry, University of Washington, Seattle, Washington 98109
| | - Jianhai Du
- Department of Ophthalmology, West Virginia University, Morgantown, West Virginia 26506; Department of Biochemistry, West Virginia University, Morgantown, West Virginia 26506.
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16
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Spermidine Oxidation-Mediated Degeneration of Retinal Pigment Epithelium in Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4128061. [PMID: 28367269 PMCID: PMC5359532 DOI: 10.1155/2017/4128061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/05/2017] [Accepted: 01/29/2017] [Indexed: 11/19/2022]
Abstract
Retinal pigment epithelium (RPE) degeneration is a crucial event in dry age-related macular degeneration and gyrate atrophy. The polyamine spermidine has been shown to induce RPE cell death in vitro. The present study aimed to establish a novel in vivo model of spermidine-induced RPE degeneration and to determine whether spermidine-induced RPE cell death involves oxidative mechanisms. In this study, spermidine caused ARPE-19 cell death in a concentration-dependent manner. This effect was prevented by removal of serum from the culture medium or treatment with amine oxidase inhibitors, N-acetylcysteine (NAC), or aldehyde dehydrogenase (ALDH). Intravitreal injection of spermidine into rats significantly increased the permeability of the blood-retinal barrier and decreased the amplitudes of scotopic electroretinogram a- and b-waves. Histological analysis revealed that spermidine induced vacuolation, atrophy, and dropout of RPE cells, leading to the disruption of photoreceptor outer segments. Simultaneous intravitreal administration of NAC and ALDH with spermidine prominently inhibited the functional and morphological changes induced by spermidine. In conclusion, this study demonstrated that the intravitreal administration of spermidine induced RPE cell dysfunction and death followed by photoreceptor degeneration in rats. These effects of spermidine are thought to be mediated by oxidative stress and a toxic aldehyde generated during spermidine oxidation.
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17
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Rackayova V, Cudalbu C, Pouwels PJW, Braissant O. Creatine in the central nervous system: From magnetic resonance spectroscopy to creatine deficiencies. Anal Biochem 2016; 529:144-157. [PMID: 27840053 DOI: 10.1016/j.ab.2016.11.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 10/20/2022]
Abstract
Creatine (Cr) is an important organic compound acting as intracellular high-energy phosphate shuttle and in energy storage. While located in most cells where it plays its main roles in energy metabolism and cytoprotection, Cr is highly concentrated in muscle and brain tissues, in which Cr also appears to act in osmoregulation and neurotransmission. This review discusses the basis of Cr metabolism, synthesis and transport within brain cells. The importance of Cr in brain function and the consequences of its impaired metabolism in primary and secondary Cr deficiencies are also discussed. Cr and phosphocreatine (PCr) in living systems can be well characterized using in vivo magnetic resonance spectroscopy (MRS). This review describes how 1H MRS allows the measurement of Cr and PCr, and how 31P MRS makes it possible to estimate the creatine kinase (CK) rate constant and so detect dynamic changes in the Cr/PCr/CK system. Absolute quantification by MRS using creatine as internal reference is also debated. The use of in vivo MRS to study brain Cr in a non-invasive way is presented, as well as its use in clinical and preclinical studies, including diagnosis and treatment follow-up in patients.
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Affiliation(s)
- Veronika Rackayova
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Petra J W Pouwels
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| | - Olivier Braissant
- Service of Biomedicine, Neurometabolic Unit, Lausanne University Hospital, Lausanne, Switzerland.
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18
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Sakamoto K, Mori A, Nakahara T, Morita M, Ishii K. Effect of Long-Term Treatment of L-Ornithine on Visual Function and Retinal Histology in the Rats. Biol Pharm Bull 2015; 38:139-43. [DOI: 10.1248/bpb.b14-00491] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Masahiko Morita
- Healthcare Products Development Center, Kyowa Hakko Bio Co., Ltd
| | - Kunio Ishii
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
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19
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Bisaillon JJ, Radden LA, Szabo ET, Hughes SR, Feliciano AM, Nesta AV, Petrovic B, Palanza KM, Lancinskas D, Szmurlo TA, Artus DC, Kapper MA, Mulrooney JP, King TR. The retarded hair growth ( rhg) mutation in mice is an allele of ornithine aminotransferase ( Oat). Mol Genet Metab Rep 2014; 1:378-390. [PMID: 25264521 PMCID: PMC4171744 DOI: 10.1016/j.ymgmr.2014.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Because of the similar phenotypes they generate and their proximate reported locations on Chromosome 7, we tested the recessive retarded hair growth (rhg) and frizzy (fr) mouse mutations for allelism, but found instead that these defects complement. To discover the molecular basis of rhg, we analyzed a large intraspecific backcross panel that segregated for rhg and restricted this locus to a 0.9 Mb region that includes fewer than ten genes, only five of which have been reported to be expressed in skin. Complementation testing between rhg and a recessive null allele of fibroblast growth factor receptor 2 eliminated Fgfr2 as the possible basis of the retarded hair growth phenotype, but DNA sequencing of another of these candidates, ornithine aminotransferase (Oat), revealed a G to C transversion specifically associated with the rhg allele that would result in a glycine to alanine substitution at residue 353 of the gene product. To test whether this missense mutation might cause the mutant phenotype, we crossed rhg/rhg mice with mice that carried a recessive, perinatal-lethal, null mutation in Oat (designated OatΔ herein). Hybrid offspring that inherited both rhg and OatΔ displayed markedly delayed postnatal growth and hair development, indicating that these two mutations are allelic, and suggesting strongly that the G to C mutation in Oat is responsible for the retarded hair growth phenotype. Comparisons among +/+, +/rhg, rhg/rhg and rhg/OatΔ mice showed plasma ornithine levels and ornithine aminotransferase activities (in liver lysates) consistent with this assignment. Because histology of 7- and 12-month-old rhg/rhg and rhg/OatΔ retinas revealed chorioretinal degeneration similar to that described previously for OatΔ/OatΔ mice, we suggest that the rhg mutant may offer an ideal model for gyrate atrophy of the choroid and retina (GACR) in humans, which is also caused by the substitution of glycine 353 in some families. Genetic mapping identifies a small number of candidates for the mouse rhg mutation. Complementation testing between a null allele of Fgfr2 and rhg rules out allelism. A null allele of ornithine aminotransferase (Oat) fails to complement rhg. The rhg mutation results from a missense mutation in Oat. Mutant rhg/rhg mice show diminished OAT function, and chorioretinal degeneration.
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Affiliation(s)
- Jason J Bisaillon
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Legairre A Radden
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Eric T Szabo
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Samantha R Hughes
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Aaron M Feliciano
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Alex V Nesta
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Belinda Petrovic
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Kenneth M Palanza
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Dainius Lancinskas
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Theodore A Szmurlo
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - David C Artus
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Martin A Kapper
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - James P Mulrooney
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
| | - Thomas R King
- Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06053, USA
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20
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Hereditary Choroidal Diseases. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00043-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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21
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Cho KI, Searle K, Webb M, Yi H, Ferreira PA. Ranbp2 haploinsufficiency mediates distinct cellular and biochemical phenotypes in brain and retinal dopaminergic and glia cells elicited by the Parkinsonian neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Cell Mol Life Sci 2012; 69:3511-27. [PMID: 22821000 PMCID: PMC3445802 DOI: 10.1007/s00018-012-1071-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/04/2012] [Accepted: 06/21/2012] [Indexed: 11/25/2022]
Abstract
Many components and pathways transducing multifaceted and deleterious effects of stress stimuli remain ill-defined. The Ran-binding protein 2 (RanBP2) interactome modulates the expression of a range of clinical and cell-context-dependent manifestations upon a variety of stressors. We examined the role of Ranbp2 haploinsufficiency on cellular and metabolic manifestations linked to tyrosine-hydroxylase (TH+) dopaminergic neurons and glial cells of the brain and retina upon acute challenge to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a parkinsonian neurotoxin, which models facets of Parkinson disease. MPTP led to stronger akinetic parkinsonism and slower recovery in Ranbp2+/− than wild-type mice without viability changes of brain TH+-neurons of either genotype, with the exception of transient nuclear atypia via changes in chromatin condensation of Ranbp2+/− TH+-neurons. Conversely, the number of wild-type retinal TH+-amacrine neurons compared to Ranbp2+/− underwent milder declines without apoptosis followed by stronger recoveries without neurogenesis. These phenotypes were accompanied by a stronger rise of EdU+-proliferative cells and non-proliferative gliosis of GFAP+-Müller cells in wild-type than Ranbp2+/− that outlasted the MPTP-insult. Finally, MPTP-treated wild-type and Ranbp2+/− mice present distinct metabolic footprints in the brain or selective regions thereof, such as striatum, that are supportive of RanBP2-mediated regulation of interdependent metabolic pathways of lysine, cholesterol, free-fatty acids, or their β-oxidation. These studies demonstrate contrasting gene-environment phenodeviances and roles of Ranbp2 between dopaminergic and glial cells of the brain and retina upon oxidative stress-elicited signaling and factors triggering a continuum of metabolic and cellular manifestations and proxies linked to oxidative stress, and chorioretinal and neurological disorders such as Parkinson.
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Affiliation(s)
- Kyoung-in Cho
- Department of Ophthalmology, Duke University Medical Center, DUEC 3802, 2351 Erwin Road, Durham, NC 27710 USA
| | - Kelly Searle
- Department of Ophthalmology, Duke University Medical Center, DUEC 3802, 2351 Erwin Road, Durham, NC 27710 USA
- Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, 21205 MD
| | - Mason Webb
- Department of Ophthalmology, Duke University Medical Center, DUEC 3802, 2351 Erwin Road, Durham, NC 27710 USA
| | - Haiqing Yi
- Department of Ophthalmology, Duke University Medical Center, DUEC 3802, 2351 Erwin Road, Durham, NC 27710 USA
| | - Paulo A. Ferreira
- Department of Ophthalmology, Duke University Medical Center, DUEC 3802, 2351 Erwin Road, Durham, NC 27710 USA
- Department of Pathology, Duke University Medical Center, Durham, NC 27710 USA
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22
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Sergouniotis PI, Davidson AE, Lenassi E, Devery SR, Moore AT, Webster AR. Retinal Structure, Function, and Molecular Pathologic Features in Gyrate Atrophy. Ophthalmology 2012; 119:596-605. [DOI: 10.1016/j.ophtha.2011.09.017] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 09/07/2011] [Accepted: 09/08/2011] [Indexed: 10/14/2022] Open
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23
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de Sain-van der Velden MGM, Rinaldo P, Elvers B, Henderson M, Walter JH, Prinsen BHCMT, Verhoeven-Duif NM, de Koning TJ, van Hasselt P. The Proline/Citrulline Ratio as a Biomarker for OAT Deficiency in Early Infancy. JIMD Rep 2012; 6:95-9. [PMID: 23430945 PMCID: PMC3565682 DOI: 10.1007/8904_2011_122] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 11/22/2011] [Accepted: 11/30/2011] [Indexed: 01/18/2023] Open
Abstract
Deficiency of ornithine-δ-aminotransferase (OAT) in humans results in gyrate atrophy. Early diagnosis may allow initiation of treatment before irreversible damage has occurred. However, diagnosis is commonly delayed well into adulthood because of the nonspecific character of initial symptoms. Here, we report findings in a neonate who was evaluated because of a positive family history of OAT deficiency. The reversed enzymatic flux in early infancy resulted in borderline low ornithine concentration - evoking urea cycle disturbances - and increased proline. In addition, plasma citrulline was low. Consequently, the proline/citrulline ratio in plasma was increased compared to controls. To find out whether amino acid profiling in neonatal dried blood spots is suitable to detect OAT deficiency, we evaluated the original newborn dried blood spots of two affected patients and compared it with a database of >450,000 newborns tested in Minnesota since 2004. Proline concentrations (777 and 1,381 μmol/L) were above the 99 percentile (776 μmol/L) of the general population, and citrulline concentrations (4.5 and 4.9 μmol/L) only just above the 1 percentile (4.37 μmol/L). The proline/citrulline ratio was 172.9 and 281.8, respectively. This ratio was calculated retrospectively in the normal population, and the 99 percentile was 97.6. Applying this ratio for NBS could lead to early and specific detection of neonatal OAT deficiency, with no additional expense to newborn screening laboratories quantifying amino acids. Given that early diagnosis of OAT disease can lead to earlier treatment and prevent visual impairment, further studies are indicated to evaluate whether newborn screening for OAT deficiency is warranted.
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Affiliation(s)
- Monique G M de Sain-van der Velden
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, 85090, 3508, Utrecht, The Netherlands,
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24
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Meyer JS, Howden SE, Wallace KA, Verhoeven AD, Wright LS, Capowski EE, Pinilla I, Martin JM, Tian S, Stewart R, Pattnaik B, Thomson J, Gamm DM. Optic vesicle-like structures derived from human pluripotent stem cells facilitate a customized approach to retinal disease treatment. Stem Cells 2011; 29:1206-18. [PMID: 21678528 PMCID: PMC3412675 DOI: 10.1002/stem.674] [Citation(s) in RCA: 346] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Differentiation methods for human induced pluripotent stem cells (hiPSCs) typically yield progeny from multiple tissue lineages, limiting their use for drug testing and autologous cell transplantation. In particular, early retina and forebrain derivatives often intermingle in pluripotent stem cell cultures, owing to their shared ancestry and tightly coupled development. Here, we demonstrate that three-dimensional populations of retinal progenitor cells (RPCs) can be isolated from early forebrain populations in both human embryonic stem cell and hiPSC cultures, providing a valuable tool for developmental, functional, and translational studies. Using our established protocol, we identified a transient population of optic vesicle (OV)-like structures that arose during a time period appropriate for normal human retinogenesis. These structures were independently cultured and analyzed to confirm their multipotent RPC status and capacity to produce physiologically responsive retinal cell types, including photoreceptors and retinal pigment epithelium (RPE). We then applied this method to hiPSCs derived from a patient with gyrate atrophy, a retinal degenerative disease affecting the RPE. RPE generated from these hiPSCs exhibited a disease-specific functional defect that could be corrected either by pharmacological means or following targeted gene repair. The production of OV-like populations from human pluripotent stem cells should facilitate the study of human retinal development and disease and advance the use of hiPSCs in personalized medicine.
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Affiliation(s)
- Jason S. Meyer
- Waisman Center, University of Wisconsin, Madison WI 53705
| | - Sara E. Howden
- Department of Cell & Regenerative Biology, University of Wisconsin, Madison WI 53705
- The Genome Center of Wisconsin, University of Wisconsin, Madison WI 53705
- Morgridge Institute for Research, Madison WI 53706
| | | | | | | | | | - Isabel Pinilla
- Department of Ophthalmology, Blesa University Hospital and the Instituto Aragones de Ciencias de la Salud, Zaragoza, Spain
| | | | - Shulan Tian
- Morgridge Institute for Research, Madison WI 53706
| | - Ron Stewart
- Morgridge Institute for Research, Madison WI 53706
| | - Bikash Pattnaik
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison WI 53705
- Department of Pediatrics, University of Wisconsin, Madison WI 53705
- Eye Research Institute, University of Wisconsin, Madison WI 53705
| | - James Thomson
- Department of Cell & Regenerative Biology, University of Wisconsin, Madison WI 53705
- The Genome Center of Wisconsin, University of Wisconsin, Madison WI 53705
- Morgridge Institute for Research, Madison WI 53706
- Department of Molecular, Cellular, & Developmental Biology, University of California Santa Barbara, Santa Barbara CA 93106
| | - David M. Gamm
- Waisman Center, University of Wisconsin, Madison WI 53705
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison WI 53705
- Eye Research Institute, University of Wisconsin, Madison WI 53705
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25
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Abstract
We reviewed the literature on ornithine supplementation and related topics. Nutritionists and physicians have reported that ornithine supplementation is useful. Paediatricians and biochemists have reported that ornithine is supplemented for NH3detoxification in the hyperornithinaemia–hyperammonaemia–homocitrullinuria (HHH) syndrome. In contrast, ophthalmic researchers have reported retinotoxicity associated with high-dose ornithine.In vivoandin vitroexperiments have shown that high concentrations of ornithine or its metabolites are toxic to the retinal pigment epithelial (RPE) cells. Long-term (exceeding a few years) and high concentrations (exceeding 600 μmol/l) of ornithine in the blood induce retinal toxicity in gyrate atrophy of the choroid and retina (GA). Intermittent high levels of ornithine do not lead to retinal lesions. Constant blood ornithine levels between 250 and 600 μmol/l do not induce retinal lesions or cause a very slowly progressive retinal degeneration. Blood ornithine levels below 250 μmol/l do not produce retinal alteration. We concluded that short-term, low-dose or transient high-dose ornithine intake is safe for the retina; its nutritional usefulness and effect on NH3detoxification are supported by many researchers, but the effect may be limited; and long-term, high-dose ornithine intake may be risky for the retina. Patients with GA should avoid taking ornithine; amino acid supplementation should be administered carefully for patients with the HHH syndrome, relatives of patients with GA (heterozygotes) and subjects with RPE lesions; and blood ornithine levels and retinal conditions should be evaluated in individuals taking long-term, high-dose ornithine.
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Poll-The BT, Maillette de Buy Wenniger-Prick CJ. The eye in metabolic diseases: clues to diagnosis. Eur J Paediatr Neurol 2011; 15:197-204. [PMID: 21511505 DOI: 10.1016/j.ejpn.2011.03.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 03/20/2011] [Indexed: 11/17/2022]
Abstract
Ophthalmologic manifestations occur in various inborn errors of metabolism (IEM), including small molecule disorders and organelle disorders. In a minority of diseases the occurrence of eye abnormalities could be attributed to direct toxic mechanisms of abnormal metabolic products or accumulation of normal metabolites by errors of synthetic pathways or by deficient energy metabolism. The age of onset of ocular abnormalities in IEM is variable, but onset often begins from birth to childhood. The major IEM associated with eye abnormalities include errors of lipid metabolism, carbohydrate metabolism, protein metabolism, and metal metabolism. IEM disorders with ocular motor manifestations include lipid storage diseases, neurotransmitter disorders and respiratory chain disorders. The purpose of this article is to describe ocular phenotypes associated with IEM, focusing on those diseases in which the ocular involvement is seen relatively early in the course of the disease. As therapeutic approaches become available for certain groups of IEM, the need for early diagnosis is increasingly important.
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Affiliation(s)
- B T Poll-The
- Academic Medical Center, Department of Pediatric Neurology Emma Children's Hospital (H7-282), PO Box 22660, 1100 DD Amsterdam, The Netherlands.
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Howden SE, Gore A, Li Z, Fung HL, Nisler BS, Nie J, Chen G, McIntosh BE, Gulbranson DR, Diol NR, Taapken SM, Vereide DT, Montgomery KD, Zhang K, Gamm DM, Thomson JA. Genetic correction and analysis of induced pluripotent stem cells from a patient with gyrate atrophy. Proc Natl Acad Sci U S A 2011; 108:6537-42. [PMID: 21464322 PMCID: PMC3080993 DOI: 10.1073/pnas.1103388108] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Gene-corrected patient-specific induced pluripotent stem (iPS) cells offer a unique approach to gene therapy. Here, we begin to assess whether the mutational load acquired during gene correction of iPS cells is compatible with use in the treatment of genetic causes of retinal degenerative disease. We isolated iPS cells free of transgene sequences from a patient with gyrate atrophy caused by a point mutation in the gene encoding ornithine-δ-aminotransferase (OAT) and used homologous recombination to correct the genetic defect. Cytogenetic analysis, array comparative genomic hybridization (aCGH), and exome sequencing were performed to assess the genomic integrity of an iPS cell line after three sequential clonal events: initial reprogramming, gene targeting, and subsequent removal of a selection cassette. No abnormalities were detected after standard G-band metaphase analysis. However, aCGH and exome sequencing identified two deletions, one amplification, and nine mutations in protein coding regions in the initial iPS cell clone. Except for the targeted correction of the single nucleotide in the OAT locus and a single synonymous base-pair change, no additional mutations or copy number variation were identified in iPS cells after the two subsequent clonal events. These findings confirm that iPS cells themselves may carry a significant mutational load at initial isolation, but that the clonal events and prolonged cultured required for correction of a genetic defect can be accomplished without a substantial increase in mutational burden.
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Affiliation(s)
- Sara E. Howden
- Morgridge Institute for Research, Madison, WI 53715
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53707-7365
- Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706
| | - Athurva Gore
- Department of Bioengineering, University of California at San Diego, La Jolla, CA 92093
| | - Zhe Li
- Department of Bioengineering, University of California at San Diego, La Jolla, CA 92093
| | - Ho-Lim Fung
- Department of Bioengineering, University of California at San Diego, La Jolla, CA 92093
| | | | - Jeff Nie
- Morgridge Institute for Research, Madison, WI 53715
| | - Goukai Chen
- Morgridge Institute for Research, Madison, WI 53715
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53707-7365
- Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706
| | - Brian E. McIntosh
- Morgridge Institute for Research, Madison, WI 53715
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53707-7365
- Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706
| | - Daniel R. Gulbranson
- Morgridge Institute for Research, Madison, WI 53715
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53707-7365
- Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706
| | - Nicole R. Diol
- Morgridge Institute for Research, Madison, WI 53715
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53707-7365
- Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706
| | | | - David T. Vereide
- Morgridge Institute for Research, Madison, WI 53715
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53707-7365
- Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706
| | | | - Kun Zhang
- Department of Bioengineering, University of California at San Diego, La Jolla, CA 92093
| | - David M. Gamm
- Department of Ophthalmology and Visual Sciences, Waisman Center Stem Cell Research Program, Eye Research Institute, University of Wisconsin, Madison, WI 53705; and
| | - James A. Thomson
- Morgridge Institute for Research, Madison, WI 53715
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53707-7365
- Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106
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Sokoro AAH, Lepage J, Antonishyn N, McDonald R, Rockman-Greenberg C, Irvine J, Lehotay DC. Diagnosis and high incidence of hyperornithinemia-hyperammonemia-homocitrullinemia (HHH) syndrome in northern Saskatchewan. J Inherit Metab Dis 2010; 33 Suppl 3:S275-81. [PMID: 20574716 DOI: 10.1007/s10545-010-9148-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 05/19/2010] [Accepted: 05/26/2010] [Indexed: 10/19/2022]
Abstract
Mutations in the SLC25A15 gene, encoding the human inner mitochondrial membrane ornithine transporter, are thought to be responsible for hyperornithinemia-hyperammonemia-homocitrullinemia (HHH) syndrome, a rare autosomal recessive condition. HHH syndrome has been detected in several small, isolated communities in northern Saskatchewan (SK). To determine the incidence of HHH syndrome in these communities, a PCR method was set up to detect F188Δ, the common French-Canadian mutation. Neonatal blood spots collected from all newborns from the high risk area were genotyped for the F188Δ mutation for seven consecutive years. Using DNA analysis, we estimated that the heterozygote frequency for the mutant allele for HHH syndrome to be about 1 in 19 individuals, predicting one affected child with HHH syndrome for approximately every 1,500 individuals (1 in 1,550 live births; 1 child every 12 years) in this isolated population. The frequency for the mutant allele for HHH syndrome in this isolated community is probably the highest in the world for this rare disorder. We determined that ornithine levels, by tandem mass spectrometry, were not abnormal in newborns with F188Δ mutation, carriers and normals. Ornithine rises to abnormally high levels at some time after birth well past the time that the newborn screening blood spot is collected. The timing or the reasons for the delayed rise of ornithine in affected children with HHH syndrome have not been determined. Newborn screening for HHH Syndrome in this high risk population is only possible by detection of the mutant allele using DNA analysis.
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Affiliation(s)
- AbdulRazaq A H Sokoro
- Department of Pathology, Diagnostic Services of Manitoba & University of Manitoba, Health Sciences Centre, Winnipeg, MB, Canada
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Béard E, Braissant O. Synthesis and transport of creatine in the CNS: importance for cerebral functions. J Neurochem 2010; 115:297-313. [DOI: 10.1111/j.1471-4159.2010.06935.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Machalińska A, Lubiński W, Kłos P, Kawa M, Baumert B, Penkala K, Grzegrzółka R, Karczewicz D, Wiszniewska B, Machaliński B. Sodium iodate selectively injuries the posterior pole of the retina in a dose-dependent manner: morphological and electrophysiological study. Neurochem Res 2010; 35:1819-27. [PMID: 20725778 PMCID: PMC2957578 DOI: 10.1007/s11064-010-0248-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2010] [Indexed: 11/30/2022]
Abstract
Sequential morphological and functional features of retinal damage in mice exposed to different doses (40 vs. 20 mg/kg) of sodium iodate (NaIO3) were analyzed. Retinal morphology, apoptosis (TUNEL assay), and function (electroretinography; ERG) were examined at several time points after NaIO3 administration. The higher dose of NaIO3 caused progressive degeneration of the whole retinal area and total suppression of scotopic and photopic ERG. In contrast, the lower dose induced much less severe degeneration in peripheral part of retina along with a moderate decline of b- and a-wave amplitudes in ERG, corroborating the presence of regions within retina that retain their function. The peak of photoreceptor apoptosis was found on the 3rd day, but the lower dose induced more intense reaction within the central retina than in its peripheral region. In conclusion, these results indicate that peripheral area of the retina reveals better resistance to NaIO3 injury than its central part.
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Affiliation(s)
- Anna Machalińska
- Department of Histology and Embryology, Pomeranian Medical University, Szczecin, Poland.
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31
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Inherited metabolic disorders involving the eye: a clinico-biochemical perspective. Eye (Lond) 2009; 24:507-18. [PMID: 19798114 DOI: 10.1038/eye.2009.229] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The diagnosis of inborn errors of metabolism is challenging for most physicians. Improvements in medical technology and greater knowledge of the human genome are resulting in significant changes in the diagnosis, classification, and treatment of inherited metabolic disorders (IMDs). Many known inborn errors of metabolism will be recognised earlier or treated differently because of these changes. It is important that physicians recognise the clinical signs of IMDs and know when to propose advanced laboratory testing or referral to a higher centre for better patient management. Ocular manifestations occur in various metabolic disorders. Although there is an extensive understanding of many inborn errors of metabolism at the biochemical, molecular, and metabolic levels, little is known about their pathogenesis. In particular, how systemic metabolic disease contributes to ocular defects remains to be elucidated in IMDs. The occurrence of eye abnormalities could be due to direct toxic mechanisms of abnormal metabolic products or accumulation of normal metabolites by errors of synthetic pathways or by deficient energy metabolism. A detailed ophthalmological assessment is essential. Definitive diagnosis and management of patients with IMDs is ideally carried out by a combination of specialists, including an ophthalmologist, paediatrician, biochemist, and medical geneticist. Recent advances in the diagnosis and treatment of IMDs have substantially improved the prognosis for many of these conditions.
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Short-term correction of arginase deficiency in a neonatal murine model with a helper-dependent adenoviral vector. Mol Ther 2009; 17:1155-63. [PMID: 19367256 DOI: 10.1038/mt.2009.65] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Neonatal gene therapy has the potential to ameliorate abnormalities before disease onset. Our gene knockout of arginase I (AI) deficiency is characterized by increasing hyperammonemia, neurological deterioration, and early death. We constructed a helper-dependent adenoviral vector (HDV) carrying AI and examined for correction of this defect. Neonates were administered 5 x 10(9) viral particles/g and analyzed for survival, arginase activity, and ammonia and amino acids levels. The life expectancy of arg(-/-) mice increased to 27 days while controls died at 14 days with hyperammonemia and in extremis. Death correlated with a decrease in viral DNA/RNA per cell as liver mass increased. Arginase assays demonstrated that vector-injected hepatocytes had ~20% activity of heterozygotes at 2 weeks of age. Hepatic arginine and ornithine in treated mice were similar to those of saline-injected heterozygotes at 2 weeks, whereas ammonia was normal. By 26 days, arginase activity in the treated arg(-/-) livers declined to <10%, and arginine and ornithine increased. Ammonia levels began increasing by day 25, suggesting the cause of death to be similar to that of uninjected arg(-/-) mice, albeit at a later time. These studies demonstrate that the AI deficient newborn mouse can be temporarily corrected and rescued using a HDV.
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33
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Grover S, Fishman GA. Choroidal Dystrophies. Ophthalmology 2009. [DOI: 10.1016/b978-0-323-04332-8.00085-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Hu CAA, Khalil S, Zhaorigetu S, Liu Z, Tyler M, Wan G, Valle D. Human Delta1-pyrroline-5-carboxylate synthase: function and regulation. Amino Acids 2008; 35:665-72. [PMID: 18401542 DOI: 10.1007/s00726-008-0075-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 03/24/2008] [Indexed: 11/25/2022]
Abstract
Mammalian Delta(1)-pyrroline-5-carboxylate synthase (P5CS) is a bifunctional ATP- and NAD(P)H-dependent mitochondrial enzyme that catalyzes the coupled phosphorylation and reduction-conversion of L: -glutamate to P5C, a pivotal step in the biosynthesis of L: -proline, L: -ornithine and L: -arginine. Previously, we reported cloning and characterization of two P5CS transcript variants generated by exon sliding that encode two protein isoforms differing only by a two amino acid-insert at the N-terminus of the gamma-glutamyl kinase active site. The short form (P5CS.short) is highly expressed in the gut and is inhibited by ornithine. In contrast, the long form (P5CS.long) is expressed ubiquitously and is insensitive to ornithine. Interestingly, we found that all the established human cell lines we have studied expressed P5CS.long but not P5CS.short. In addition, expression of P5CS.long can be modulated by hormones: downregulation by hydrocortisone and dexamethasone and upregulation by estradiol, for example. Using a quantitative proteomic approach, we showed that P5CS.long is upregulated by p53 in p53-induced apoptosis in DLD-1 colorectal cancer cells. Functional genomic analysis confirmed that there are two p53-binding consensus sequences in the promoter region and in the intron 1 of the human P5CS gene. Interestingly, overexpression of P5CS by adenoviruses harboring P5CS.long or P5CS.short in various cell types has no effect on cell growth or survival. It would be of importance to further investigate the role of P5CS as a p53 downstream effector and how P5CS.short expression is regulated by hormones and factors of alternative splicing in cells isolated from model animals.
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Affiliation(s)
- C-A A Hu
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA.
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Cideciyan AV, Swider M, Aleman TS, Sumaroka A, Schwartz SB, Roman MI, Milam AH, Bennett J, Stone EM, Jacobson SG. ABCA4-associated retinal degenerations spare structure and function of the human parapapillary retina. Invest Ophthalmol Vis Sci 2006; 46:4739-46. [PMID: 16303974 PMCID: PMC2579900 DOI: 10.1167/iovs.05-0805] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To study the parapapillary retinal region in patients with ABCA4-associated retinal degenerations. METHODS Patients with Stargardt disease or cone-rod dystrophy and disease-causing variants in the ABCA4 gene were included. Fixation location was determined under fundus visualization, and central cone-mediated vision was measured. Intensity and texture abnormalities of autofluorescence (AF) images were quantified. Parapapillary retina of an eye donor with ungenotyped Stargardt disease was examined microscopically. RESULTS AF images ranged from normal, to spatially homogenous abnormal increase of intensity, to a spatially heterogenous speckled pattern, to variably sized patches of low intensity. A parapapillary ring of normal-appearing AF was visible at all disease stages. Quantitative analysis of the intensity and texture properties of AF images showed the preserved region to be an annulus, at least 0.6 mm wide, surrounding the optic nerve head. A similar region of relatively preserved photoreceptor nuclei was apparent in the donor retina. In patients with foveal fixation, there was better cone sensitivity at a parapapillary locus in the nasal retina than at the same eccentricity in the temporal retina. In patients with eccentric fixation, approximately 30% had a preferred retinal locus in the parapapillary retina. CONCLUSIONS Human retinal degenerations caused by ABCA4 mutations spare the structure of retina and RPE in a circular parapapillary region that commonly serves as the preferred fixation locus when central vision is lost. The retina between fovea and optic nerve head could serve as a convenient, accessible, and informative region for structural and functional studies to determine natural history or outcome of therapy in ABCA4-associated disease.
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Affiliation(s)
- Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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36
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Do DV, Zhang K, Garibaldi DC, Carr RE, Sunness JS. Hereditary Choroidal Disease. Retina 2006. [DOI: 10.1016/b978-0-323-02598-0.50024-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Johnson DA, Sharma RK, Allan K, Ray R, Johnson LR. Immunocytochemical localization of polyamines during attachment and spreading of retinal pigment epithelial and intestinal epithelial cells. ACTA ACUST UNITED AC 2005; 58:269-80. [PMID: 15236357 DOI: 10.1002/cm.20014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In order to form and maintain a protective barrier for photoreceptors, the retinal pigment epithelium relies on integrin signaling and related pathways to form adhesion complexes, undergo cell spreading, and establish a confluent cellular monolayer. Polyamines are multifunctional polycations that are essential for cell attachment and spreading, although their exact mechanisms of action are as yet unclear. We report new immunocytochemical evidence suggesting that in the cells of retinal pigment epithelium and also the intestinal epithelium, polyamines are present in a population of intracellular vesicles that appear transiently during initial stages of cell spreading. In newly attached cells with minimal spreading, the vesicles are seen near the nucleus, whereas in more highly spread cells, the vesicles are localized to the plasma membrane, near, but not precisely co-localized with an enzyme marker for adhesion complexes, focal adhesion kinase. We also observe pronounced nuclear staining in newly attached cells that have not spread, whereas this staining is decreased in cells that have spread. Nuclear staining has been previously reported in other cell types and has been attributed to DNA binding of polyamines, which is known to stabilize chromatin structure. We hypothesize that the appearance of polyamine vesicles near focal adhesions of cells undergoing attachment and spreading may reflect the mechanism by which polyamine pools are targeted to appropriate interaction sites necessary for the assembly of adhesion complexes. Alternatively, the vesicles could represent the mechanism by which polyamines are removed from the nucleus and possibly released from the cell.
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Affiliation(s)
- Dianna A Johnson
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, USA.
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Xu S, Wang Y, Zhao H, Zhang L, Xiong W, Yau KW, Hiel H, Glowatzki E, Ryugo DK, Valle D. PHR1, a PH domain-containing protein expressed in primary sensory neurons. Mol Cell Biol 2004; 24:9137-51. [PMID: 15456885 PMCID: PMC517893 DOI: 10.1128/mcb.24.20.9137-9151.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Previously, we identified PHR1 as an abundantly expressed gene in photoreceptors and showed that it encodes four isoforms, each with N-terminal pleckstrin homology (PH) and C-terminal transmembrane domains. To better understand PHR1 function and expression, we made a Phr1 null mouse by inserting a beta-galactosidase/neor cassette into exon 3. In addition to photoreceptors, we found abundant expression of specific Phr1 splice forms in olfactory receptor neurons and vestibular and cochlear hair cells. We also found Phr1 expression in cells with a possible sensory function, including peripheral retinal ganglion cells, cochlear interdental cells, and neurons of the circumventricular organ. Despite this discrete expression in known and putative sensory neurons, mice lacking PHR1 do not have overt sensory deficits.
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Affiliation(s)
- Shunbin Xu
- McKusick-Nathans Institute of Genetic Medicine, Howard Hughes Medical Institute, PCTB 519, 733 N. Broadway, Baltimore, MD 21205, USA
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Poll-The BT, Maillette de Buy Wenniger-Prick LJ, Barth PG, Duran M. The eye as a window to inborn errors of metabolism. J Inherit Metab Dis 2003; 26:229-44. [PMID: 12889663 DOI: 10.1023/a:1024493318913] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ocular manifestations in inborn errors of metabolism occur in many diseases and may be associated with any part of all eye components. In a minority of diseases it is possible to attribute the eye symptoms to a single hereditary pathogenetic mechanism. More often the aetiological relationship of the ocular defects to the metabolic disease is unknown. Diverse pathogenetic mechanisms may act via a common pathological pathway inducing ocular damage. The occurrence of eye abnormalities in metabolic disorders suggests that they are associated with direct toxic actions, errors of synthetic pathways or deficient energy metabolism. In this review, metabolic disorders with major abnormalities in the cornea, lens, retina and optic nerve are presented. In all cases, an appropriate combined approach by the ophthalmologist, paediatrician/neurologist, geneticist and clinical biochemist is the only way to diagnostic success.
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Affiliation(s)
- B T Poll-The
- Department of Pediatrics/Emma Children's Hospital and Laboratory of Genetic Metabolic Diseases, Amsterdam, The Netherlands.
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Kiuchi K, Yoshizawa K, Shikata N, Moriguchi K, Tsubura A. Morphologic characteristics of retinal degeneration induced by sodium iodate in mice. Curr Eye Res 2002; 25:373-9. [PMID: 12789545 DOI: 10.1076/ceyr.25.6.373.14227] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Retinal degeneration induced by sodium iodate (NaIO( 3)) in mice was evaluated morphologically. METHODS Male and female ICR and C57BL mice were intraperitoneally administered 100 mg/kg NaIO(3) at 7 weeks of age, and were killed 6, 12, 24 hrs, and 3, 7 and 28 days after the treatment. Retinas were examined histologically, ultrastructurally, immunohistochemically, and by the TUNEL method. RESULTS Retinal degeneration was evoked in all NaIO(3)-treated mice. The primary site of damage appeared in the retinal pigment epithelial (RPE) cells followed by photoreceptor cell degeneration. Initially, the RPE cells showed necrosis starting 6 hrs post-NaIO(3), followed by photoreceptor outer segment disruption and photoreceptor cell apoptosis at 24 hrs; photoreceptor cell apoptosis peaked at day 3 and was completed by day 7. At day 3, Müller cell proliferation, macrophage migration within the retina, and regeneration of damaged RPE cells occurred. Finally at day 7 and day 28, the retina showed a mosaic pattern of relatively normal retina and areas lacking RPE cells and photoreceptor cells. CONCLUSIONS RPE cell necrosis followed by photoreceptor cell apoptosis and the resulting mosaic pattern of the retina phenotypically resembles gyrate atrophy of the choroid and retina.
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Affiliation(s)
- Katsuji Kiuchi
- Department of Pathology II, Kansai Medical University, Osaka, Moriguchi, Japan
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Abstract
The past decade has witnessed extraordinary progress in retinal disease gene identification, the analysis of animal and tissue culture models of disease processes, and the integration of this information with clinical observations and with retinal biochemistry and physiology. During this period over twenty retinal disease genes were identified and for many of these genes there are now significant insights into their role in disease. This review presents an overview of the basic and clinical biology of the retina, summarizes recent progress in understanding the molecular mechanisms of inherited retinal diseases, and offers an assessment of the role that genetics will play in the next phase of research in this area.
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Affiliation(s)
- A Rattner
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Wang T, Steel G, Milam AH, Valle D. Correction of ornithine accumulation prevents retinal degeneration in a mouse model of gyrate atrophy of the choroid and retina. Proc Natl Acad Sci U S A 2000; 97:1224-9. [PMID: 10655512 PMCID: PMC15576 DOI: 10.1073/pnas.97.3.1224] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Deficiency of ornithine-delta-aminotransferase (OAT) in humans results in gyrate atrophy of the choroid and retina (GA), an autosomal recessive disorder characterized by ornithine accumulation and a progressive chorioretinal degeneration of unknown pathogenesis. To determine whether chronic, systemic reduction of ornithine can prevent this form of retinal degeneration, we used an arginine-restricted diet to maintain long term reduction of ornithine in a mouse model of OAT-deficiency (Oat(-/-)) produced by gene targeting. We evaluated the mice over a 12-month period by measurement of plasma amino acids, electroretinograms, and retinal histologic and ultrastructural studies. We found that an arginine-restricted diet substantially reduces plasma ornithine levels and completely prevents retinal degeneration in Oat(-/-). This result indicates that ornithine accumulation is a necessary factor in the pathophysiology of the retinal degeneration in GA and that restoration of OAT activity in retina is not required for effective treatment of GA.
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Affiliation(s)
- T Wang
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Ando A, Ueda M, Uyama M, Masu Y, Okumura T, Ito S. Heterogeneity in ornithine cytotoxicity of bovine retinal pigment epithelial cells in primary culture. Exp Eye Res 2000; 70:89-96. [PMID: 10644424 DOI: 10.1006/exer.1999.0750] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gyrate atrophy of the choroid and retina is a chorioretinal degeneration caused by hyperornithinemia and a deficiency of ornithine-delta-aminotransferase (OAT). We recently showed that ornithine exhibits cytotoxicity to human retinal pigment epithelial (RPE) cell lines treated with the OAT inhibitor, 5-fluoromethylornithine (5-FMOrn), and suggested that this system may be an in vitro model of gyrate atrophy. In the present study, in order to apply this system to primary cultured RPE cells, we freshly prepared RPE cells from bovine eyes and studied the effect of ornithine on cell damage. Two phenotypes, epithelioid and fusiform, which coexisted in the primary culture and epithelioid phenotype cells, but not fusiform ones, were severely damaged and partially detached from the substrate by 10 m m ornithine and 0.5 m m 5-FMOrn. Neither ornithine nor 5-FMOrn alone exhibited such cytotoxicity to both phenotypes of RPE cells. Proline significantly prevented the ornithine-induced cytotoxicity. Epithelioid and fusiform phenotypes isolated from the primary culture showed different distribution of actin filaments. A combination of ornithine and 5-FMOrn time-dependently inhibited [(3)H]thymidine incorporation in the epithelioid, but not fusiform, cells. Proline prevented the inhibition of [(3)H]thymidine incorporation by ornithine in 5-FMOrn-treated epithelioid cells. Furthermore, l -azetidine-2-carboxylic acid, a collagen synthesis inhibitor, reduced [(3)H]thymidine incorporation in epithelioid, but not fusiform, cells, which was reversed by proline. These results demonstrate that the epithelioid phenotype of bovine RPE cells becomes susceptible to ornithine following inactivation of OAT. The phenotypic cells and its prevention by proline may provide insight into biochemical triggers that induce gyrate atrophy.
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Affiliation(s)
- A Ando
- Department of Ophthalmology, Kansai Medical University, 10-15 Fumizono, Moriguchi, Osaka, 570-8506, Japan
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Schmidt A, Tief K, Yavuzer U, Beermann F. Ectopic expression of RET results in microphthalmia and tumors in the retinal pigment epithelium. Int J Cancer 1999; 80:600-5. [PMID: 9935163 DOI: 10.1002/(sici)1097-0215(19990209)80:4<600::aid-ijc19>3.0.co;2-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The retinal pigment epithelium (RPE) is essential for eye development by interacting with the overlaying neuroepithelium. Regulatory sequences of the gene encoding for tyrosinase-related protein 1 (TRP-1), linked to the lacZ reporter gene, lead to strong and specific beta-galactosidase expression in the RPE. We asked how the oncogene ret would affect this epithelial cell type during mouse development. We used the TRP-1 promoter to express ret in the developing RPE, and obtained transgenic mouse lines, which showed mild to severe microphthalmia. During development, the RPE changed to a stratified epithelium with reduced or absent pigmentation from E10.5 onward. In addition, proliferation of RPE cells and tumor formation were observed from E12.5 onward. These early events prevent closure of choroid fissure and lead to microphthalmia and secondary malformations after birth. We conclude that ret transgene expression in the RPE prevents normal differentiation of this epithelial layer and induces proliferation and tumor formation. The appearance of the microphthalmic phenotype underlines the requirement of a normally developed RPE for eye development.
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Affiliation(s)
- A Schmidt
- Swiss Institute for Experimental Cancer Research (ISREC), Epalinges
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Nussenblatt RB, Csaky K. Perspectives on gene therapy in the treatment of ocular inflammation. Eye (Lond) 1998; 11 ( Pt 2):217-21. [PMID: 9349416 DOI: 10.1038/eye.1997.55] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Gene therapy may become a powerful therapeutic strategy. However, the application of this method in the treatment of ocular disease presents us with interesting and unique questions. Gene therapy for ocular inflammatory disease has the potential for both therapeutic interventions and a method for studying mechanism of disease. An evolving philosophy on this subject would support the use of somatic gene therapy for ocular inflammatory disease, even if not life threatening. Major technical questions remain, including the use of the appropriate vector, the best methodology for the stable insertion into the genome, and the duration and intensity of expression of the transgene. Various transgenes encoding a wide variety of proteins can be envisaged for the insertion of genes. The study of gyrate atrophy, an hereditary ocular disorder and an excellent candidate for gene therapy, has given us enormous information in the development of practical therapeutic strategies, as have in vitro studies of gene insertion. Future concerns will need to concentrate on the use of better methods for gene insertion and homologous recombination techniques for the development of animal models and later as a strategy for gene therapy. The use of gene therapy as a drug delivery system must also be considered. In addition, the elucidation of the various events controlling transcription for the expression of transgenes in various resident ocular cells is necessary.
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