1
|
Thompson DA, Bach M, McAnany JJ, Šuštar Habjan M, Viswanathan S, Robson AG. ISCEV standard for clinical pattern electroretinography (2024 update). Doc Ophthalmol 2024; 148:75-85. [PMID: 38488946 PMCID: PMC10954931 DOI: 10.1007/s10633-024-09970-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 02/18/2024] [Indexed: 03/17/2024]
Abstract
The pattern electroretinogram (PERG) is a localized retinal response evoked by a contrast-reversing pattern, usually a black and white checkerboard, which provides information about macular and retinal ganglion cell function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV; www.iscev.org ) presents an updated and revised Standard for clinical PERG testing. This replaces the 2013 and all earlier versions. Minimum protocols for basic PERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis and monitoring purposes, while responding to evolving clinical practices and technology. The main changes in the updated ISCEV Standard for clinical PERG include expanded guidance about large stimulus fields, stimulus parameters for simultaneous PERG and pattern visual evoked potential recording, baseline drift correction, and use of consistent ambient room lighting. These changes aim to provide a clinically relevant document about current practice which will facilitate good quality recordings and inter-laboratory comparisons.
Collapse
Affiliation(s)
- D A Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Sight and Sound Centre, Great Ormond Street Hospital for Children NHS Trust, London, WC1N 3AJ, UK.
- Great Ormond Street Institute for Child Health, University College London, London, UK.
| | - M Bach
- Eye Center, Medical Center - Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - J J McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - M Šuštar Habjan
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva ulica 46, 1000, Ljubljana, Slovenia
| | - S Viswanathan
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
| | - A G Robson
- Department of Electrophysiology, Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK
- Institute of Ophthalmology, University College London, London, UK
| |
Collapse
|
2
|
Jolly JK, Grigg JR, McKendrick AM, Fujinami K, Cideciyan AV, Thompson DA, Matsumoto C, Asaoka R, Johnson C, Dul MW, Artes PH, Robson AG. ISCEV and IPS guideline for the full-field stimulus test (FST). Doc Ophthalmol 2024; 148:3-14. [PMID: 38238632 PMCID: PMC10879267 DOI: 10.1007/s10633-023-09962-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 02/21/2024]
Abstract
The full-field stimulus test (FST) is a psychophysical technique designed for the measurement of visual function in low vision. The method involves the use of a ganzfeld stimulator, as used in routine full-field electroretinography, to deliver full-field flashes of light. This guideline was developed jointly by the International Society for Clinical Electrophysiology of Vision (ISCEV) and Imaging and Perimetry Society (IPS) in order to provide technical information, promote consistency of testing and reporting, and encourage convergence of methods for FST. It is intended to aid practitioners and guide the formulation of FST protocols, with a view to future standardisation.
Collapse
Affiliation(s)
- J K Jolly
- Vision and Eye Research Institute, Anglia Ruskin University, Young Street, Cambridge, CB1 2LZ, UK.
| | - J R Grigg
- Save Sight Institute, Specialty of Clinical Ophthalmology and Eye Health, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
- Eye Genetics Research Unit, Sydney Children's Hospitals Network, Save Sight Institute, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - A M McKendrick
- Lions Eye Institute, University of Western Australia, Perth, Australia
- School of Allied Health, University of Western Australia, Crawley, Australia
| | - K Fujinami
- Laboratory of Visual Physiology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
- Institute of Ophthalmology, University College London, London, UK
| | - A V Cideciyan
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, University of Pennsylvania, Philadelphia, USA
| | - D A Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic, Department of Ophthalmology, Sight and Sound Centre, Great Ormond Street Hospital for Children NHS Trust, London, UK
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - C Matsumoto
- Department of Ophthalmology, Kindai University, Osakasayama, Japan
| | - R Asaoka
- Department of Ophthalmology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan
- Seirei Christopher University, Hamamatsu, Shizuoka, Japan
- Nanovision Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka, Japan
- The Graduate School for the Creation of New Photonics Industries, Shizuoka, Japan
| | - C Johnson
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
- School of Optometry, The Ohio State University, Columbus, IA, USA
| | - M W Dul
- Department of Biological and Vision Science, College of Optometry, State University of New York, New York, USA
| | - P H Artes
- Faculty of Health, University of Plymouth, Plymouth, UK
| | - A G Robson
- Institute of Ophthalmology, University College London, London, UK
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
| |
Collapse
|
3
|
Handley SE, Thompson DA, Liasis A, Bowman RJ, Rahi JS. 7 Scoping review of homonymous hemianopia in childhood. BMJ Open Ophthalmol 2023; 8:A3. [PMID: 37798009 DOI: 10.1136/bmjophth-2023-biposa.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023] Open
Abstract
Cerebral visual impairment (CVI) encompasses a heterogeneous group of disorders and a spectrum of types of visual impairments. Research is needed to characterise the different forms of CVI and identify the specific needs of these groups to inform individualised patient care. Homonymous hemianopia (HH) is a definable visual field defect that affect some children with CVI. As part of a new research programme, we conducted a scoping review of the literature on HH in children and young people to map current knowledge and identify evidence gaps.We used the PRISMA extension for Scoping Reviews methodology. Multiple online databases were searched using terms associated with 'homonymous hemianopia' and 'children'. This yielded 1588 papers which were screened by two reviewers. Of these 1001 were excluded at abstract screen and a further 415 excluded after full text review, with full text unavailable for 15. Data were extracted and charted from 157 studies and additional grey literature.Interim analysis shows reported studies are predominantly from high income countries with a paucity of higher-level evidence, and a preponderance of case reports. Most papers reported causative pathology and diagnosis of HH. There was minimal attention to or evidence relating to intervention. Child-specific grey literature on HH was limited.This review collates the current evidence-base for HH in children. It demonstrates the important evidence-gap relating to intervention in these cases that would help inform more individualised care. Similar scoping reviews may be prove useful in assessing the evidence relating to other definable groups within the CVI umbrella.
Collapse
Affiliation(s)
- S E Handley
- Great Ormond Street Hospital for Children, London, UK
| | - D A Thompson
- Great Ormond Street Hospital for Children, London, UK
| | - A Liasis
- Great Ormond Street Hospital for Children, London, UK
| | - R J Bowman
- Great Ormond Street Hospital for Children, London, UK
| | - J S Rahi
- Great Ormond Street Hospital for Children, London, UK
| |
Collapse
|
4
|
Feathers KL, Jia L, Khan NW, Smith A, Ma JX, Ali RR, Thompson DA. Gene Supplementation in Mice Heterozygous for the D477G-RPE65 Variant Implicated in Autosomal Dominant Retinitis Pigmentosa. Hum Gene Ther 2023. [PMID: 37014074 DOI: 10.1089/hum.2022.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
Abstract
The use of AAV-RPE65 vectors for gene supplementation has achieved spectacular success as a treatment for individuals with autosomal recessive retinal disease (arRD) caused by biallelic mutations in the visual cycle gene RPE65. However, the efficacy of this approach in treating autosomal dominant retinitis pigmentosa (adRP) associated with a monoallelic mutation encoding a rare D477G RPE65 variant has not been studied. Although lacking a severe phenotype, we now find that knock-in mice heterozygous for D477G RPE65 (D477G KI mice) can be used to evaluate outcomes of AAV-RPE65 gene-supplementation. Total RPE65 protein levels, which are decreased in heterozygous D477G KI mice, were doubled following subretinal delivery of rAAV2/5.hRPE65p.hRPE65. In addition, rates of recovery of the chromophore 11-cis retinal after bleaching were significantly increased in eyes that received AAV-RPE65, consistent with increased RPE65 isomerase activity. While dark-adapted chromophore levels and a-wave amplitudes were not affected, b-wave recovery rates were modestly improved. The present findings establish that gene supplementation enhances 11-cis retinal synthesis in heterozygous D477G KI mice, and complement previous studies showing that chromophore therapy results in improved vision in individuals with adRP associated with D477G RPE65.
Collapse
Affiliation(s)
- Kecia L Feathers
- University of Michigan Medical School, 12266, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States;
| | - Lin Jia
- University of Michigan Medical School, 12266, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States;
| | - Naheed W Khan
- University of Michigan Medical School, 12266, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States;
| | - Alexander Smith
- King's College London, 4616, London, United Kingdom of Great Britain and Northern Ireland;
| | - Jian-Xing Ma
- Wake Forest School of Medicine, 12279, Biochemistry, Winston-Salem, North Carolina, United States;
| | - Robin R Ali
- King's College London, 4616, London, United Kingdom of Great Britain and Northern Ireland;
| | - Debra A Thompson
- University of Michigan Medical School, 12266, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States
- University of Michigan Medical School, 12266, Department of Biological Chemistry, Ann Arbor, Michigan, United States;
| |
Collapse
|
5
|
Bowman R, Walters B, Smith V, Prise KL, Handley SE, Green K, Mankad K, O'Hare P, Dahl C, Jorgensen M, Opocher E, Hargrave D, Thompson DA. Visual outcomes and predictors in optic pathway glioma: a single centre study. Eye (Lond) 2023; 37:1178-1183. [PMID: 35562551 PMCID: PMC10101957 DOI: 10.1038/s41433-022-02096-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 03/31/2022] [Accepted: 05/06/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND/AIMS Optic pathway gliomas (OPGs) may cause progressive visual loss despite chemotherapy. Newer, less toxic treatments might be given earlier, depending on visual prognosis. We aimed to investigate the prognostic value of visual evoked potentials (VEP) and optical coherence tomography (OCT). METHODS A retrospective study of OPG patients (treated 2003-2017) was conducted. Primary outcome was PEDIG category visual acuity in better and worse eyes (good < = 0.2, moderate 0.3-0.6 and poor > = 0.7 logMAR). Binary logistic regression analysis was used to identify predictors of these outcomes. RESULTS 60 patients (32 Neurofibromatosis type 1 [NF1] and 28 sporadic) had median presentation age 49 months (range 17-183) (NF1) and 27 months (range 4-92) (sporadic). Median follow up was 82 months (range 12-189 months). At follow up 24/32 (75%) of NF1 children and 14/28 (50%) of sporadic children had good better eye visual acuity and 11/32 (34%) of NF1 children and 15/28 (54%) of sporadics had poor worse eye acuity. Mean peripapillary retinal nerve fibre layer (RNFL) thickness predicted good better eye final acuity (OR 0.799, 95%CI 0.646-0.987, p = 0.038). Presenting with visual symptoms (OR 0.22 95% CI 0.001-0.508, p = 0.017) and poorer VEP scores (OR 2.35 95% CI 1.1-5.03, p = 0.027) predicted poor worse eye final acuity. 16 children had homonymous hemianopias at follow up, predicted by poor presenting binocular VEP score (OR 1.449 95%CI 1.052-1.995, p = 0.02). CONCLUSIONS We found that both RNFL thickness on OCT and VEP were useful in predicting future visual acuity and vision and potentially in planning treatment. We had a high prevalence of homonymous hemianopia.
Collapse
Affiliation(s)
- R Bowman
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England.
- University College London, Great Ormond Street Institute of Child Health, WC1N 1EH, London, England.
| | - B Walters
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - V Smith
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - K L Prise
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - S E Handley
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
- University College London, Great Ormond Street Institute of Child Health, WC1N 1EH, London, England
| | - K Green
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - K Mankad
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
- University College London, Great Ormond Street Institute of Child Health, WC1N 1EH, London, England
| | - P O'Hare
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - C Dahl
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - M Jorgensen
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - E Opocher
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
| | - D Hargrave
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
- University College London, Great Ormond Street Institute of Child Health, WC1N 1EH, London, England
| | - D A Thompson
- Great Ormond Street Hospital, Great Ormond Street NHS Foundation Trust, WC1N 3JH, London, England
- University College London, Great Ormond Street Institute of Child Health, WC1N 1EH, London, England
| |
Collapse
|
6
|
Liton PB, Boesze-Battaglia K, Boulton ME, Boya P, Ferguson TA, Ganley IG, Kauppinnen A, Laurie GW, Mizushima N, Morishita H, Russo R, Sadda J, Shyam R, Sinha D, Thompson DA, Zacks DN. AUTOPHAGY IN THE EYE: FROM PHYSIOLOGY TO PATHOPHYSOLOGY. Autophagy Rep 2023; 2:2178996. [PMID: 37034386 PMCID: PMC10078619 DOI: 10.1080/27694127.2023.2178996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/26/2023] [Indexed: 03/05/2023]
Abstract
Autophagy is a catabolic self-degradative pathway that promotes the degradation and recycling of intracellular material through the lysosomal compartment. Although first believed to function in conditions of nutritional stress, autophagy is emerging as a critical cellular pathway, involved in a variety of physiological and pathophysiological processes. Autophagy dysregulation is associated with an increasing number of diseases, including ocular diseases. On one hand, mutations in autophagy-related genes have been linked to cataracts, glaucoma, and corneal dystrophy; on the other hand, alterations in autophagy and lysosomal pathways are a common finding in essentially all diseases of the eye. Moreover, LC3-associated phagocytosis, a form of non-canonical autophagy, is critical in promoting visual cycle function. This review collects the latest understanding of autophagy in the context of the eye. We will review and discuss the respective roles of autophagy in the physiology and/or pathophysiology of each of the ocular tissues, its diurnal/circadian variation, as well as its involvement in diseases of the eye.
Collapse
Affiliation(s)
- Paloma B. Liton
- Departments of Ophthalmology & Pathology, Duke School of Medicine, Duke University, Durham, NC 27705, USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA 19104, USA
| | - Michael E. Boulton
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham (UAB), Birmingham, AL, USA
| | - Patricia Boya
- Department of Neuroscience and Movement Science. Faculty of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Thomas A. Ferguson
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Ian G. Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Anu Kauppinnen
- Faculty of Health and Sciences, School of Pharmacy, University of Eastern Finland, 70210 Kuopio, Finland
| | - Gordon W. Laurie
- Departments of Cell Biology, Ophthalmology and Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, 113-0033, Japan
| | - Hideaki Morishita
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, 113-0033, Japan
- Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Rossella Russo
- Preclinical and Translational Pharmacology, Glaucoma Unit, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
| | - Jaya Sadda
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Debasish Sinha
- Department of Ophthalmology, Cell Biology, and Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Debra A. Thompson
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - David N. Zacks
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| |
Collapse
|
7
|
Chen L, Perera ND, Karoukis AJ, Feathers KL, Ali RR, Thompson DA, Fahim AT. Oxidative stress differentially impacts apical and basolateral secretion of angiogenic factors from human iPSC-derived retinal pigment epithelium cells. Sci Rep 2022; 12:12694. [PMID: 35882889 PMCID: PMC9325713 DOI: 10.1038/s41598-022-16701-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 07/14/2022] [Indexed: 11/10/2022] Open
Abstract
The retinal pigment epithelium (RPE) is a polarized monolayer that secretes growth factors and cytokines towards the retina apically and the choroid basolaterally. Numerous RPE secreted proteins have been linked to the pathogenesis of age-related macular degeneration (AMD). The purpose of this study was to determine the differential apical and basolateral secretome of RPE cells, and the effects of oxidative stress on directional secretion of proteins linked to AMD and angiogenesis. Tandem mass tag spectrometry was used to profile proteins in human iPSC-RPE apical and basolateral conditioned media. Changes in secretion after oxidative stress induced by H2O2 or tert-butyl hydroperoxide (tBH) were investigated by ELISA and western analysis. Out of 926 differentially secreted proteins, 890 (96%) were more apical. Oxidative stress altered the secretion of multiple factors implicated in AMD and neovascularization and promoted a pro-angiogenic microenvironment by increasing the secretion of pro-angiogenic molecules (VEGF, PTN, and CRYAB) and decreasing the secretion of anti-angiogenic molecules (PEDF and CFH). Apical secretion was impacted more than basolateral for PEDF, CRYAB and CFH, while basolateral secretion was impacted more for VEGF, which may have implications for choroidal neovascularization. This study lays a foundation for investigations of dysfunctional RPE polarized protein secretion in AMD and other chorioretinal degenerative disorders.
Collapse
Affiliation(s)
- Lisheng Chen
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - N Dayanthi Perera
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Athanasios J Karoukis
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Kecia L Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Robin R Ali
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
- KCL Centre for Cell and Gene Therapy, London, WC2R 2LS, England, UK
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Abigail T Fahim
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA.
| |
Collapse
|
8
|
Boyer NP, Thompson DA, Koutalos Y. Relative Contributions of All-Trans and 11-Cis Retinal to Formation of Lipofuscin and A2E Accumulating in Mouse Retinal Pigment Epithelium. Invest Ophthalmol Vis Sci 2021; 62:1. [PMID: 33523199 PMCID: PMC7862733 DOI: 10.1167/iovs.62.2.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Bis-retinoids are a major component of lipofuscin that accumulates in the retinal pigment epithelium (RPE) in aging and age-related macular degeneration (AMD). Although bis-retinoids are known to originate from retinaldehydes required for the light response of photoreceptor cells, the relative contributions of the chromophore, 11-cis retinal, and photoisomerization product, all-trans retinal, are unknown. In photoreceptor outer segments, all-trans retinal, but not 11-cis retinal, is reduced by retinol dehydrogenase 8 (RDH8). Using Rdh8−/− mice, we evaluated the contribution of increased all-trans retinal to the formation and stability of RPE lipofuscin. Methods Rdh8−/− mice were reared in cyclic-light or darkness for up to 6 months, with selected light-reared cohorts switched to dark-rearing for the final 1 to 8 weeks. The bis-retinoid A2E was measured from chloroform-methanol extracts of RPE-choroid using HPLC-UV/VIS spectroscopy. Lipofuscin fluorescence was measured from whole flattened eyecups (excitation, 488 nm; emission, 565–725 nm). Results Cyclic-light-reared Rdh8−/− mice accumulated A2E and RPE lipofuscin approximately 1.5 times and approximately 2 times faster, respectively, than dark-reared mice. Moving Rdh8−/− mice from cyclic-light to darkness resulted in A2E levels less than expected to have accumulated before the move. Conclusions Our findings establish that elevated levels of all-trans retinal present in cyclic-light-reared Rdh8−/− mice, which remain low in wild-type mice, contribute only modestly to RPE lipofuscin formation and accumulation. Furthermore, decreases in A2E levels occurring after moving cyclic-light-reared Rdh8−/− mice to darkness are consistent with processing of A2E within the RPE and the existence of a mechanism that could be a therapeutic target for controlling A2E cytotoxicity.
Collapse
Affiliation(s)
- Nicholas P Boyer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Debra A Thompson
- Department of Ophthalmology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States.,Department of Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, Michigan, United States
| | - Yiannis Koutalos
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| |
Collapse
|
9
|
Zhang Q, Presswalla F, Ali RR, Zacks DN, Thompson DA, Miller JML. Pharmacologic activation of autophagy without direct mTOR inhibition as a therapeutic strategy for treating dry macular degeneration. Aging (Albany NY) 2021; 13:10866-10890. [PMID: 33872219 PMCID: PMC8109132 DOI: 10.18632/aging.202974] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 03/13/2021] [Indexed: 12/15/2022]
Abstract
Dry age-related macular degeneration (AMD) is marked by the accumulation of extracellular and intracellular lipid-rich deposits within and around the retinal pigment epithelium (RPE). Inducing autophagy, a conserved, intracellular degradative pathway, is a potential treatment strategy to prevent disease by clearing these deposits. However, mTOR inhibition, the major mechanism for inducing autophagy, disrupts core RPE functions. Here, we screened autophagy inducers that do not directly inhibit mTOR for their potential as an AMD therapeutic in primary human RPE culture. Only two out of more than thirty autophagy inducers tested reliably increased autophagy flux in RPE, emphasizing that autophagy induction mechanistically differs across distinct tissues. In contrast to mTOR inhibitors, these compounds preserved RPE health, and one inducer, the FDA-approved compound flubendazole (FLBZ), reduced the secretion of apolipoprotein that contributes to extracellular deposits termed drusen. Simultaneously, FLBZ increased production of the lipid-degradation product β-hydroxybutyrate, which is used by photoreceptor cells as an energy source. FLBZ also reduced the accumulation of intracellular deposits, termed lipofuscin, and alleviated lipofuscin-induced cellular senescence and tight-junction disruption. FLBZ triggered compaction of lipofuscin-like granules into a potentially less toxic form. Thus, induction of RPE autophagy without direct mTOR inhibition is a promising therapeutic approach for dry AMD.
Collapse
Affiliation(s)
- Qitao Zhang
- Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
| | - Feriel Presswalla
- Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
| | - Robin R. Ali
- Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
- KCL Centre for Cell and Gene Therapy, London, England WC2R 2LS, United Kingdom
| | - David N. Zacks
- Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
| | - Debra A. Thompson
- Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48105, USA
| | - Jason ML. Miller
- Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
| |
Collapse
|
10
|
Soriano LF, Chowdhury MMU, Cooper SM, Cousen P, Dawe S, Havelin A, Holden CR, Johnston GA, Orton DI, Ramoutar A, Stone NM, Thompson DA, Buckley DA. Current prevalence and relevance of positive patch test reactions to cosmetic and noncosmetic isothiazolinones in the UK. Br J Dermatol 2021; 185:223-225. [PMID: 33657657 DOI: 10.1111/bjd.19898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/26/2021] [Accepted: 02/27/2021] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | - P Cousen
- The James Cook University Hospital, Middlesbrough, TS4 3BW, UK
| | - S Dawe
- West Hertfordshire Hospitals NHS Trust, UK
| | - A Havelin
- The James Cook University Hospital, Middlesbrough, TS4 3BW, UK
| | - C R Holden
- Sheffield Teaching Hospital NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield, S10 2JF, UK
| | - G A Johnston
- Leicester Royal Infirmary, Leicester, LE1 5WW, UK
| | - D I Orton
- 152 Harley St, Marylebone, London, W1G 7LH, UK
| | - A Ramoutar
- Sheffield Teaching Hospital NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield, S10 2JF, UK
| | - N M Stone
- Royal Gwent Hospital, Newport, NP20 2UB, UK
| | - D A Thompson
- Birmingham Skin Centre, Sandwell and West Birmingham Hospitals NHS Trust, City Hospital, Birmingham, B18 7QH, UK
| | | |
Collapse
|
11
|
Soriano LF, Bertram CG, Chowdhury MMU, Cousen P, Divekar P, Ghaffar SA, Green C, Havelin A, Holden CR, Johnston GA, Mughal AA, Nic Dhonncha E, Sabroe RA, Stone NM, Thompson DA, Wilkinson SM, Buckley DA. Prevalence of allergic contact dermatitis to decyl and lauryl glucoside in the UK and Ireland. Br J Dermatol 2020; 184:571-573. [PMID: 33090453 DOI: 10.1111/bjd.19603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/08/2020] [Accepted: 10/11/2020] [Indexed: 01/27/2023]
Affiliation(s)
| | - C G Bertram
- Royal Infirmary of Edinburgh, Edinburgh, EH16 4SA, UK
| | | | - P Cousen
- The James Cook University Hospital, Middlesbrough, TS4 3BW, UK
| | - P Divekar
- Royal Cornwall Hospitals NHS Trust, Truro, Cornwall, TR1 3LJ, UK
| | | | - C Green
- Ninewells Hospital, Dundee, DD2 1SG, UK
| | - A Havelin
- The James Cook University Hospital, Middlesbrough, TS4 3BW, UK
| | - C R Holden
- Sheffield Teaching Hospital NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield, S10 2JF, UK
| | - G A Johnston
- Leicester Royal Infirmary, Leicester, LE1 5WW, UK
| | - A A Mughal
- Singleton Hospital, Swansea, SA2 8QA, UK
| | - E Nic Dhonncha
- South Infirmary Victoria University Hospital, Cork, T12 X23H, Ireland
| | - R A Sabroe
- Sheffield Teaching Hospital NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield, S10 2JF, UK
| | - N M Stone
- Royal Gwent Hospital, Newport, NP20 2UB, UK
| | - D A Thompson
- Birmingham Skin Centre, Sandwell and West Birmingham Hospitals NHS Trust, City Hospital, Birmingham, B18 7QH, UK
| | | | | |
Collapse
|
12
|
Thompson DA, Iannaccone A, Ali RR, Arshavsky VY, Audo I, Bainbridge JWB, Besirli CG, Birch DG, Branham KE, Cideciyan AV, Daiger SP, Dalkara D, Duncan JL, Fahim AT, Flannery JG, Gattegna R, Heckenlively JR, Heon E, Jayasundera KT, Khan NW, Klassen H, Leroy BP, Molday RS, Musch DC, Pennesi ME, Petersen-Jones SM, Pierce EA, Rao RC, Reh TA, Sahel JA, Sharon D, Sieving PA, Strettoi E, Yang P, Zacks DN. Advancing Clinical Trials for Inherited Retinal Diseases: Recommendations from the Second Monaciano Symposium. Transl Vis Sci Technol 2020; 9:2. [PMID: 32832209 PMCID: PMC7414644 DOI: 10.1167/tvst.9.7.2] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 03/12/2020] [Indexed: 12/18/2022] Open
Abstract
Major advances in the study of inherited retinal diseases (IRDs) have placed efforts to develop treatments for these blinding conditions at the forefront of the emerging field of precision medicine. As a result, the growth of clinical trials for IRDs has increased rapidly over the past decade and is expected to further accelerate as more therapeutic possibilities emerge and qualified participants are identified. Although guided by established principles, these specialized trials, requiring analysis of novel outcome measures and endpoints in small patient populations, present multiple challenges relative to study design and ethical considerations. This position paper reviews recent accomplishments and existing challenges in clinical trials for IRDs and presents a set of recommendations aimed at rapidly advancing future progress. The goal is to stimulate discussions among researchers, funding agencies, industry, and policy makers that will further the design, conduct, and analysis of clinical trials needed to accelerate the approval of effective treatments for IRDs, while promoting advocacy and ensuring patient safety.
Collapse
Affiliation(s)
- Debra A Thompson
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Alessandro Iannaccone
- Department of Ophthalmology, Duke Eye Center, Duke University Medical Center, Durham, NC, USA
| | - Robin R Ali
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA.,Institute of Ophthalmology, University College London, London, UK
| | - Vadim Y Arshavsky
- Department of Ophthalmology, Duke Eye Center, Duke University Medical Center, Durham, NC, USA
| | - Isabelle Audo
- Sorbonne Université, Institut de la Vision, INSERM, CNRS, Paris, France.,CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, Paris, France
| | | | - Cagri G Besirli
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Kari E Branham
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Artur V Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Steven P Daiger
- Human Genetics Center, School of Public Health, University of Texas Health Science Center Houston, Houston, TX, USA
| | - Deniz Dalkara
- Sorbonne Université, Institut de la Vision, INSERM, CNRS, Paris, France
| | - Jacque L Duncan
- Department of Ophthalmology, University of California-San Francisco, San Francisco, CA, USA
| | - Abigail T Fahim
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - John G Flannery
- Helen Wills Neuroscience Institute, University of California-Berkeley, Berkeley, CA, USA
| | | | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, Toronto, Ontario, Canada
| | - K Thiran Jayasundera
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Naheed W Khan
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Henry Klassen
- Gavin Herbert Eye Institute, Stem Cell Research Center, University of California-Irvine, Irvine, CA, USA
| | - Bart P Leroy
- Department of Ophthalmology and Center Medical Genetics, Ghent University Hospital and University, Ghent, Belgium.,Division of Ophthalmology and Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Robert S Molday
- Department of Biochemistry/Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - David C Musch
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Mark E Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science Center, Portland, OR, USA
| | - Simon M Petersen-Jones
- Small Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, MI, USA
| | - Eric A Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Rajesh C Rao
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Jose A Sahel
- Sorbonne Université, Institut de la Vision, INSERM, CNRS, Paris, France.,CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, Paris, France.,Fondation Ophtalmologique Rothschild, Paris, France.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Paul A Sieving
- Department of Ophthalmology and Center for Ocular Regenerative Therapy, University of California-Davis School of Medicine, Sacramento, CA, USA.,National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Enrica Strettoi
- Institute of Neuroscience, National Research Council (CNR), Pisa, Italy
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science Center, Portland, OR, USA
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | | |
Collapse
|
13
|
Rolls S, Owen E, Bertram CG, Bourke JF, Buckley DA, Chowdhury MMU, Cooper SM, Ghaffar SA, Green CM, Hughes TM, Johnston GA, Reckling CM, Thompson DA, Wakelin SH, Wilkinson M, Stone NM. What is in? What is out? Updating the British Society for Cutaneous Allergy facial series. Br J Dermatol 2020; 184:151-155. [PMID: 32282055 DOI: 10.1111/bjd.19127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND Allergic contact dermatitis (ACD) to cosmetics is widely reported. To ensure we are accurately diagnosing ACD, patch test series should be continually reviewed to identify relevant and emerging allergens and highlight those that are outdated. The current British Society for Cutaneous Allergy (BSCA) facial series recommends 26 allergens and was last modified in 2012. OBJECTIVES To review and update the BSCA facial series. METHODS We retrospectively reviewed the results from 12 UK and Ireland patch test centres' facial series from January 2016 to December 2017. We recorded the number of allergens tested in each centre and the detection rate for each allergen. Using a 0·3% positive rate as the inclusion threshold, we established which allergens in the BSCA facial series had positive patch test rates < 0·3% and > 0·3%. Allergens not in the BSCA facial series that had a positive patch test rate > 0·3% were identified. RESULTS Overall, 4224 patients were patch tested to the facial series. The number of allergens included in individual centres' facial series ranged from 24 to 66, with a total of 103 allergens tested across all centres. Twelve of the 26 allergens in the BSCA facial series had a positive patch test rate < 0·3% and 14 had a rate > 0·3%. Twenty-five allergens not recommended in the BSCA facial series had a positive patch test rate > 0·3%. CONCLUSIONS This audit has highlighted the significant variation in practice that exists among patch test centres, despite a recommended facial series. The BSCA facial series has been updated and now contains 24 allergens. Fifteen allergens remain, 11 allergens have been dropped and nine new allergens have been added.
Collapse
Affiliation(s)
- S Rolls
- Royal Gwent and Nevill Hall Hospitals, Newport, UK
| | - E Owen
- Royal Gwent and Nevill Hall Hospitals, Newport, UK
| | | | - J F Bourke
- South Infirmary Victoria University Hospital, Cork, Ireland
| | | | | | | | | | | | - T M Hughes
- Royal Gwent and Nevill Hall Hospitals, Newport, UK
| | | | | | - D A Thompson
- Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK
| | - S H Wakelin
- Imperial College Healthcare NHS Trust, London, UK
| | - M Wilkinson
- Leeds Teaching Hospital NHS Trust, Leeds, UK
| | - N M Stone
- Royal Gwent and Nevill Hall Hospitals, Newport, UK
| |
Collapse
|
14
|
Zhang Q, Presswalla F, Calton M, Charniga C, Stern J, Temple S, Vollrath D, Zacks DN, Ali RR, Thompson DA, Miller JML. Highly Differentiated Human Fetal RPE Cultures Are Resistant to the Accumulation and Toxicity of Lipofuscin-Like Material. Invest Ophthalmol Vis Sci 2019; 60:3468-3479. [PMID: 31408109 PMCID: PMC6692057 DOI: 10.1167/iovs.19-26690] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Purpose The accumulation of undigestible autofluorescent material (UAM), termed lipofuscin in vivo, is a hallmark of aged RPE. Lipofuscin derives, in part, from the incomplete degradation of phagocytized photoreceptor outer segments (OS). Whether this accumulated waste is toxic is unclear. We therefore investigated the effects of UAM in highly differentiated human fetal RPE (hfRPE) cultures. Methods Unmodified and photo-oxidized OS were fed daily to confluent cultures of ARPE-19 RPE or hfRPE. The emission spectrum, composition, and morphology of resulting UAM were measured and compared to in vivo lipofuscin. Effects of UAM on multiple RPE phenotypes were assessed. Results Compared to ARPE-19, hfRPE were markedly less susceptible to UAM buildup. Accumulated UAM in hfRPE initially resembled the morphology of lipofuscin from AMD eyes, but compacted and shifted spectrum over time to resemble lipofuscin from healthy aged human RPE. UAM accumulation mildly reduced transepithelial electrical resistance, ketogenesis, certain RPE differentiation markers, and phagocytosis efficiency, while inducing senescence and rare, focal pockets of epithelial-mesenchymal transition. However, it had no effects on mitochondrial oxygen consumption rate, certain other RPE differentiation markers, secretion of drusen components or polarity markers, nor cell death. Conclusions hfRPE demonstrates a remarkable resistance to UAM accumulation, suggesting mechanisms for efficient OS processing that may be lost in other RPE culture models. Furthermore, while UAM alters hfRPE phenotype, the effects are modest, consistent with conflicting reports in the literature on the toxicity of lipofuscin. Our results suggest that healthy RPE may adequately adapt to and tolerate lipofuscin accumulation.
Collapse
Affiliation(s)
- Qitao Zhang
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Feriel Presswalla
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Melissa Calton
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States
| | - Carol Charniga
- Neural Stem Cell Institute, Rensselaer, New York, United States
| | - Jeffrey Stern
- Neural Stem Cell Institute, Rensselaer, New York, United States
| | - Sally Temple
- Neural Stem Cell Institute, Rensselaer, New York, United States
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States
| | - David N Zacks
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Robin R Ali
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States.,UCL Institute of Ophthalmology, London, United Kingdom
| | - Debra A Thompson
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Jason M L Miller
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| |
Collapse
|
15
|
Qiu Y, Yao J, Jia L, Thompson DA, Zacks DN. Shifting the balance of autophagy and proteasome activation reduces proteotoxic cell death: a novel therapeutic approach for restoring photoreceptor homeostasis. Cell Death Dis 2019; 10:547. [PMID: 31320609 PMCID: PMC6639359 DOI: 10.1038/s41419-019-1780-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/26/2019] [Accepted: 06/27/2019] [Indexed: 12/13/2022]
Abstract
The P23H variant of rhodopsin results in misfolding of the protein, and is a common cause of the blinding disease autosomal dominant retinitis pigmentosa (adRP). We have recently demonstrated that degeneration of photoreceptor cells in retinas of P23H mice is due to the endoplasmic reticulum stress (ERS)-induced activation of autophagy that leads to a secondary proteasome insufficiency and activation of cell death pathways. We propose that this increased level of autophagy flux relative to proteasome activity, which we term the A:P ratio, represents a marker of altered photoreceptor cell homeostasis, and that therapies aimed at normalizing this ratio will result in increased photoreceptor cell survival. To test this postulate, we treated P23H mice with a chemical chaperone (4-phenylbutyric acid) to improve rhodopsin folding, or with a selective phosphodiesterase-4 inhibitor (rolipram) to increase proteasome activity. P23H mice treated with either of these agents exhibited reduced ERS, decreased autophagy flux, increased proteasome activity, and decreased activation of cell death pathways. In addition, rates of retinal degeneration were decreased, and photoreceptor morphology and visual function were preserved. These findings support the conclusion that normalizing the A:P ratio, either by reducing the ERS-induced activation of autophagy, or by increasing proteasome activity, improves photoreceptor survival, and suggest a potential new therapeutic strategy for the treatment of adRP caused by protein folding defects.
Collapse
Affiliation(s)
- Yaoyan Qiu
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Kellogg Eye Center, Ann Arbor, MI, USA.,Department of Ophthalmology, Xiangya School of medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jingyu Yao
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Kellogg Eye Center, Ann Arbor, MI, USA
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Kellogg Eye Center, Ann Arbor, MI, USA
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Kellogg Eye Center, Ann Arbor, MI, USA.,Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Kellogg Eye Center, Ann Arbor, MI, USA.
| |
Collapse
|
16
|
Feathers KL, Jia L, Perera ND, Chen A, Presswalla FK, Khan NW, Fahim AT, Smith AJ, Ali RR, Thompson DA. Development of a Gene Therapy Vector for RDH12-Associated Retinal Dystrophy. Hum Gene Ther 2019; 30:1325-1335. [PMID: 31237438 DOI: 10.1089/hum.2019.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Early-onset severe retinal dystrophy (EOSRD) is a genetically heterogeneous group of diseases resulting in serious visual disability in children. A significant number of EOSRD cases, often diagnosed as Leber congenital amaurosis (LCA13), are associated with mutations in the gene encoding retinol dehydrogenase 12 (RDH12). RDH12 is a member of the enzyme family of short-chain dehydrogenases/reductases. In the retina, RDH12 plays a critical role in reducing toxic retinaldehydes generated by visual cycle activity that is required for the light response of the photoreceptor cells. Individuals with RDH12 deficiency exhibit widespread retinal degeneration impacting both rods and cones. Although Rdh12-deficient (Rdh12-/-) mice do not exhibit retinal degeneration, functional deficits relevant to visual cycle function can be demonstrated. In the present study, we describe the development and preclinical testing of a recombinant adeno-associated viral (rAAV) vector that has the potential for use in treating EOSRD due to RDH12 mutations. Wild-type and Rdh12-/- mice that received a subretinal injection of rAAV2/5 carrying a human RDH12 cDNA driven by a human rhodopsin-kinase promoter exhibited transgene expression that was stable, correctly localized, and did not cause retinal toxicity. In addition, administration of the vector reconstituted retinal reductase activity in the retinas of Rdh12-/- mice and decreased susceptibility to light damage associated with Rdh12 deficiency, thus demonstrating potential therapeutic efficacy in an animal model that does not exhibit a retinal degeneration phenotype. These findings support further efforts to develop gene replacement therapy for individuals with RDH12 mutations.
Collapse
Affiliation(s)
- Kecia L Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Nirosha Dayanthi Perera
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Adrienne Chen
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Feriel K Presswalla
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Naheed W Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Abigail T Fahim
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Alexander J Smith
- Department of Genetics, University College London Institute of Ophthalmology, London, United Kingdom
| | - Robin R Ali
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan.,Department of Genetics, University College London Institute of Ophthalmology, London, United Kingdom
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan.,Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan
| |
Collapse
|
17
|
Fahim AT, Bouzia Z, Branham KH, Kumaran N, Vargas ME, Feathers KL, Perera ND, Young K, Khan NW, Heckenlively JR, Webster AR, Pennesi ME, Ali RR, Thompson DA, Michaelides M. Detailed clinical characterisation, unique features and natural history of autosomal recessive RDH12-associated retinal degeneration. Br J Ophthalmol 2019; 103:1789-1796. [PMID: 30979730 DOI: 10.1136/bjophthalmol-2018-313580] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/28/2019] [Accepted: 02/05/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND Defects in retinol dehydrogenase 12 (RDH12) account for 3.4%-10.5 % of Leber congenital amaurosis and early-onset severe retinal dystrophy (EOSRD) and are a potential target for gene therapy. Clinical trials in inherited retinal diseases have unique challenges, and natural history studies are critical to successful trial design. The purpose of this study was to characterise the natural history of RDH12-associated retinal degeneration. METHODS A retrospective chart review was performed in individuals with retinal degeneration and two likely disease-causing variants in RDH12. RESULTS 57 subjects were enrolled from nine countries. 33 subjects had clinical records available from childhood. The data revealed an EOSRD, with average age of onset of 4.1 years. Macular atrophy was a universal clinical finding in all subjects, as young as 2 years of age. Scotopic and photopic electroretinography (ERG) responses were markedly reduced in all subjects, and a non-recordable ERG was documented as young as 1 year of age. Assessment of visual acuity, visual field and optical coherence tomography revealed severe loss of function and structure in the majority of subjects after the age of 10 years. Widefield imaging in 23 subjects revealed a unique, variegated watercolour-like pattern of atrophy in 13 subjects and sparing of the peripapillary area in 18 subjects. CONCLUSIONS This study includes the largest collection of phenotypic data from children with RDH12-associated EOSRD and provides a comprehensive description of the timeline of vision loss in this severe, early-onset condition. These findings will help identify patients with RDH12-associated retinal degeneration and will inform future design of therapeutic trials.
Collapse
Affiliation(s)
- Abigail T Fahim
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Zaina Bouzia
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Kari H Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Neruban Kumaran
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Mauricio E Vargas
- Department of Ophthalmology, Oregon Health & Science University - Casey Eye Institute, Portland, Oregon, USA
| | - Kecia L Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - N Dayanthi Perera
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Kelly Young
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Naheed W Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Andrew R Webster
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Mark E Pennesi
- Department of Ophthalmology, Oregon Health & Science University - Casey Eye Institute, Portland, Oregon, USA
| | - Robin R Ali
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA.,Institute of Ophthalmology, University College London, London, UK
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA.,Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| |
Collapse
|
18
|
Zhang Q, Presswalla F, Feathers K, Cao X, Hughes BA, Zacks DN, Thompson DA, Miller JML. A platform for assessing outer segment fate in primary human fetal RPE cultures. Exp Eye Res 2018; 178:212-222. [PMID: 30336126 DOI: 10.1016/j.exer.2018.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 10/01/2018] [Accepted: 10/13/2018] [Indexed: 12/14/2022]
Abstract
The daily shedding and renewal of photoreceptor outer segments (OS) is critical for maintaining vision. This process relies on the efficient uptake, degradation, and sorting of shed OS material by the retinal pigment epithelium (RPE). Poor OS degradation has been linked to retinal degenerations such as Stargardt disease and may contribute to macular degeneration. While primary human fetal RPE cultures have emerged as a valuable model of in vivo human RPE function, surprisingly few studies have utilized the model for tracking the degradation and fate of OS components in the RPE. Here, we establish an improved platform for studying this topic by modifying existing protocols and creating new methods. Our human fetal culture model facilitates studies of RPE secretion in response to OS ingestion, preserves RPE differentiation and polarization during live-cell imaging of OS phagocytosis, and minimizes costs. We optimize Mer tyrosine kinase-dependent OS phagocytosis assays specifically in human fetal cultures and provide a simple and accurate method for measuring total OS consumption by the RPE. Finally, we utilize chemical transfection, dextran labeling, and immunocytochemistry to evaluate key players in OS degradation, including lysosomes and autophagy proteins. To facilitate quantification of autophagy vesicles, we develop customized image analysis macros in the Fiji/ImageJ software environment. These protocols will facilitate a broad range of studies in human fetal RPE cultures aimed at determining the ultimate fate of OS components after ingestion, a critical step in understanding the pathogenesis of numerous retinal diseases.
Collapse
Affiliation(s)
- Qitao Zhang
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Feriel Presswalla
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Kecia Feathers
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Xu Cao
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Bret A Hughes
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Jason M L Miller
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
19
|
Yao J, Qiu Y, Frontera E, Jia L, Khan NW, Klionsky DJ, Ferguson TA, Thompson DA, Zacks DN. Inhibiting autophagy reduces retinal degeneration caused by protein misfolding. Autophagy 2018; 14:1226-1238. [PMID: 29940785 PMCID: PMC6103695 DOI: 10.1080/15548627.2018.1463121] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 12/13/2022] Open
Abstract
Mutations in the genes necessary for the structure and function of vertebrate photoreceptor cells are associated with multiple forms of inherited retinal degeneration. Mutations in the gene encoding RHO (rhodopsin) are a common cause of autosomal dominant retinitis pigmentosa (adRP), with the Pro23His variant of RHO resulting in a misfolded protein that activates endoplasmic reticulum stress and the unfolded protein response. Stimulating macroautophagy/autophagy has been proposed as a strategy for clearing misfolded RHO and reducing photoreceptor death. We found that retinas from mice heterozygous for the gene encoding the RHOP23H variant (hereafter called P23H) exhibited elevated levels of autophagy flux, and that pharmacological stimulation of autophagy accelerated retinal degeneration. In contrast, reducing autophagy flux pharmacologically or by rod-specific deletion of the autophagy-activating gene Atg5, improved photoreceptor structure and function. Furthermore, proteasome levels and activity were reduced in the P23H retina, and increased when Atg5 was deleted. Our findings suggest that autophagy contributes to photoreceptor cell death in P23H mice, and that decreasing autophagy shifts the degradation of misfolded RHO protein to the proteasome and is protective. These observations suggest that modulating the flux of misfolded proteins from autophagy to the proteasome may represent an important therapeutic strategy for reducing proteotoxicity in adRP and other diseases caused by protein folding defects.
Collapse
Affiliation(s)
- Jingyu Yao
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Yaoyan Qiu
- Department of Ophthalmology, Xiangya School of medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Eric Frontera
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Naheed W. Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
| | | | - Thomas A. Ferguson
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, USA
| | - Debra A. Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - David N. Zacks
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
20
|
Greenspan SL, Singer A, Vujevich K, Marchand B, Thompson DA, Hsu YJ, Vaidya D, Stern LS, Zeldow D, Lee DB, Karp S, Recker R. Implementing a fracture liaison service open model of care utilizing a cloud-based tool. Osteoporos Int 2018; 29:953-960. [PMID: 29429033 PMCID: PMC6481927 DOI: 10.1007/s00198-017-4371-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 12/25/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE Although half of women and one-quarter of men aged 50 and older will sustain an acute low-trauma fracture, less than a quarter receive appropriate secondary fracture prevention. The goal of this quality improvement demonstration project was to implement a Fracture Liaison Service (FLS) focused on secondary prevention of an osteoporotic fracture in three open health care systems aided by a cloud-based tool. METHODS The pre-post study design examined the proportion of men and women over age 50 who received appropriate assessment (bone mineral density, vitamin D levels) and treatment (calcium/vitamin D, pharmacologic therapy) in the six months following a recently diagnosed fracture. The pre-study (Pre FLS) included a retrospective chart review for baseline data (N = 344 patients) within each health care system. In the post-evaluation (Post FLS, N = 148 patients), the FLS coordinator from each health care system examined these parameters following enrollment and for 6 months following the recently diagnosed fracture. Data were managed in the cloud-based FLS application tool. RESULTS Ninety-three participants completed the program. The FLS program increased the percentage of patients receiving bone mineral density testing from 21% at baseline to 93% (p < 0.001) Post FLS implementation. Assessments of vitamin D levels increased from 25 to 84% (p < 0.001). Patients prescribed calcium/vitamin D increased from 36% at baseline to 93% (p < 0.001) and those prescribed pharmacologic treatment for osteoporosis increased on average from 20 to 54% (p < 0.001) Post FLS. CONCLUSIONS We conclude that the FLS model of care in an open health care system, assisted by a cloud-based tool, significantly improved assessment and/or treatment of patients with a recently diagnosed osteoporotic fracture. Future studies are necessary to determine if this model of care is scalable and if such programs result in prevention of fractures. Mini-Abstract: The goal was to implement a Fracture Liaison Service (FLS) focused on secondary prevention of an osteoporotic fracture in open health care systems aided by a cloud-based tool. This model significantly improved assessment and/or treatment of patients with a recently diagnosed fracture.
Collapse
Affiliation(s)
- S L Greenspan
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
| | - A Singer
- Department of Obstetrics and Gynecology and Medicine, MedStar Georgetown University Hospital, Washington, DC, USA
| | - K Vujevich
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - B Marchand
- CECity®, a subsidiary of Premier, Inc., Pittsburgh, PA, USA
| | - D A Thompson
- Johns Hopkins Armstrong Institute for Patient Safety and Quality, Baltimore, MD, USA
| | - Y-J Hsu
- Johns Hopkins Armstrong Institute for Patient Safety and Quality, Baltimore, MD, USA
| | - D Vaidya
- Johns Hopkins Armstrong Institute for Patient Safety and Quality, Baltimore, MD, USA
| | - L S Stern
- Merck Research Labs, Merck & Co., North Wales, PA, USA
| | - D Zeldow
- National Bone Health Alliance, Arlington, VA, USA
| | - D B Lee
- National Bone Health Alliance, Arlington, VA, USA
| | - S Karp
- CECity®, a subsidiary of Premier, Inc., Pittsburgh, PA, USA
| | - R Recker
- Department of Medicine, Creighton University Hospital, Omaha, NE, USA
| |
Collapse
|
21
|
Chen C, Adler L, Goletz P, Gonzalez-Fernandez F, Thompson DA, Koutalos Y. Interphotoreceptor retinoid-binding protein removes all- trans-retinol and retinal from rod outer segments, preventing lipofuscin precursor formation. J Biol Chem 2017; 292:19356-19365. [PMID: 28972139 DOI: 10.1074/jbc.m117.795187] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 09/22/2017] [Indexed: 11/06/2022] Open
Abstract
Interphotoreceptor retinoid-binding protein (IRBP) is a specialized lipophilic carrier that binds the all-trans and 11-cis isomers of retinal and retinol, and this facilitates their transport between photoreceptors and cells in the retina. One of these retinoids, all-trans-retinal, is released in the rod outer segment by photoactivated rhodopsin after light excitation. Following its release, all-trans-retinal is reduced by the retinol dehydrogenase RDH8 to all-trans-retinol in an NADPH-dependent reaction. However, all-trans-retinal can also react with outer segment components, sometimes forming lipofuscin precursors, which after conversion to lipofuscin accumulate in the lysosomes of the retinal pigment epithelium and display cytotoxic effects. Here, we have imaged the fluorescence of all-trans-retinol, all-trans-retinal, and lipofuscin precursors in real time in single isolated mouse rod photoreceptors. We found that IRBP removes all-trans-retinol from individual rod photoreceptors in a concentration-dependent manner. The rate constant for retinol removal increased linearly with IRBP concentration with a slope of 0.012 min-1 μm-1 IRBP also removed all-trans-retinal, but with much less efficacy, indicating that the reduction of retinal to retinol promotes faster clearance of the photoisomerized rhodopsin chromophore. The presence of physiological IRBP concentrations in the extracellular medium resulted in lower levels of all-trans-retinal and retinol in rod outer segments following light exposure. It also prevented light-induced lipofuscin precursor formation, but it did not remove precursors that were already present. These findings reveal an important and previously unappreciated role of IRBP in protecting the photoreceptor cells against the cytotoxic effects of accumulated all-trans-retinal.
Collapse
Affiliation(s)
- Chunhe Chen
- From the Departments of Ophthalmology and Neurosciences, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Leopold Adler
- From the Departments of Ophthalmology and Neurosciences, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Patrice Goletz
- From the Departments of Ophthalmology and Neurosciences, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Federico Gonzalez-Fernandez
- the Departments of Ophthalmology and Pathology, University of Mississippi and G. V. (Sonny) Montgomery Veterans Affairs Medical Centers, Jackson, Mississippi 39216, and
| | - Debra A Thompson
- the Departments of Ophthalmology and Visual Sciences, and Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, Michigan 48105
| | - Yiannis Koutalos
- From the Departments of Ophthalmology and Neurosciences, Medical University of South Carolina, Charleston, South Carolina 29425,
| |
Collapse
|
22
|
Yao J, Jia L, Khan N, Lin C, Mitter SK, Boulton ME, Dunaief JL, Klionsky DJ, Guan JL, Thompson DA, Zacks DN. Deletion of autophagy inducer RB1CC1 results in degeneration of the retinal pigment epithelium. Autophagy 2016; 11:939-53. [PMID: 26075877 DOI: 10.1080/15548627.2015.1041699] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Autophagy regulates cellular homeostasis and response to environmental stress. Within the retinal pigment epithelium (RPE) of the eye, the level of autophagy can change with both age and disease. The purpose of this study is to determine the relationship between reduced autophagy and age-related degeneration of the RPE. The gene encoding RB1CC1/FIP200 (RB1-inducible coiled-coil 1), a protein essential for induction of autophagy, was selectively knocked out in the RPE by crossing Best1-Cre mice with mice in which the Rb1cc1 gene was flanked with Lox-P sites (Rb1cc1(flox/flox)). Ex vivo and in vivo analyses, including western blot, immunohistochemistry, transmission electron microscopy, fundus photography, optical coherence tomography, fluorescein angiography, and electroretinography were performed to assess the structure and function of the retina as a function of age. Deletion of Rb1cc1 resulted in multiple autophagy defects within the RPE including decreased conversion of LC3-I to LC3-II, accumulation of autophagy-targeted precursors, and increased numbers of mitochondria. Age-dependent degeneration of the RPE occurred, with formation of atrophic patches, subretinal migration of activated microglial cells, subRPE deposition of inflammatory and oxidatively damaged proteins, subretinal drusenoid deposits, and occasional foci of choroidal neovascularization. There was secondary loss of photoreceptors overlying the degenerated RPE and reduction in the electroretinogram. These observations are consistent with a critical role of autophagy in the maintenance of normal homeostasis in the aging RPE, and indicate that disruption of autophagy leads to retinal phenotypes associated with age-related degeneration.
Collapse
Key Words
- AMD, age-related macular degeneration
- ANOVA, analysis of variance
- Bru, Bruch's membrane
- CKO, conditional knockout
- CTSD, cathepsin D
- ERG, electroretinogram
- FIP200
- GCL, ganglion cell layer
- INL, inner nuclear layer
- IS, inner segment
- LAP, LC3-associated phagocytosis
- MTOR, mechanistic target of rapamycin
- OCT, optical coherence tomography
- ONL, outer nuclear layer
- OS, outer segment
- PBS, phosphate-buffered saline
- POS, photoreceptor outer segments
- RB1CC1, RB1-inducible coiled-coil 1
- RPE, retinal pigment epithelium
- age-related macular degeneration
- photoreceptor
- retina
- retinal pigment epithelium
- siRNA, small interfering ribonucleic acid.
Collapse
Affiliation(s)
- Jingyu Yao
- a Department of Ophthalmology and Visual Sciences ; University of Michigan ; Ann Arbor , MI USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Holzmueller CG, Karp S, Zeldow D, Lee DB, Thompson DA. Development of a cloud-based application for the Fracture Liaison Service model of care. Osteoporos Int 2016; 27:683-90. [PMID: 26286624 PMCID: PMC4740567 DOI: 10.1007/s00198-015-3260-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/24/2015] [Indexed: 11/13/2022]
Abstract
UNLABELLED The aims of this study are to develop a cloud-based application of the Fracture Liaison Service for practitioners to coordinate the care of osteoporotic patients after suffering primary fractures and provide a performance feedback portal for practitioners to determine quality of care. The application provides continuity of care, improved patient outcomes, and reduced medical costs. INTRODUCTION The purpose of this study is to describe the content development and functionality of a cloud-based application to broadly deploy the Fracture Liaison Service (FLS) to coordinate post-fracture care for osteoporotic patients. METHODS The Bone Health Collaborative developed the FLS application in 2013 to support practitioners' access to information and management of patients and provide a feedback portal for practitioners to track their performance in providing quality care. A five-step protocol (identify, inform, initiate, investigate, and iterate) organized osteoporotic post-fracture care-related tasks and timelines for the application. A range of descriptive data about the patient, their medical condition, therapies and care, and current providers can be collected. Seven quality of care measures from the National Quality Forum, The Joint Commission, and the Centers for Medicare and Medicaid Services can be tracked through the application. RESULTS There are five functional areas including home, tasks, measures, improvement, and data. The home, tasks, and data pages are used to enter patient information and coordinate care using the five-step protocol. Measures and improvement pages are used to enter quality measures and provide practitioners with continuous performance feedback. The application resides within a portal, running on a multitenant, private cloud-based Avedis enterprise registry platform. All data are encrypted in transit and users access the application using a password from any common web browser. CONCLUSION The application could spread the FLS model of care across the US health care system, provide continuity of care, effectively manage osteoporotic patients, improve outcomes, and reduce medical costs.
Collapse
Affiliation(s)
- C G Holzmueller
- Johns Hopkins Medicine, Armstrong Institute for Patient Safety and Quality, Johns Hopkins University School of Medicine, 750 E. Pratt Street, 15th floor, Baltimore, MD, 21202, USA
| | - S Karp
- CECity, 285 Waterfront Drive, Homestead, PA, 15120, USA
| | - D Zeldow
- National Bone Health Alliance, 1150 17th Street, NW, Suite 850, Washington, DC, 20036, USA
| | - D B Lee
- National Bone Health Alliance, 1150 17th Street, NW, Suite 850, Washington, DC, 20036, USA
| | - D A Thompson
- Johns Hopkins Medicine, Armstrong Institute for Patient Safety and Quality, Johns Hopkins University School of Medicine, 750 E. Pratt Street, 15th floor, Baltimore, MD, 21202, USA.
- School of Nursing and Bloomberg School of Public Health, Johns Hopkins University, Baltimore, USA.
| |
Collapse
|
24
|
Lin HC, Stein JD, Nan B, Childers D, Newman-Casey PA, Thompson DA, Richards JE. Association of Geroprotective Effects of Metformin and Risk of Open-Angle Glaucoma in Persons With Diabetes Mellitus. JAMA Ophthalmol 2015; 133:915-23. [PMID: 26022641 DOI: 10.1001/jamaophthalmol.2015.1440] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
IMPORTANCE Caloric restriction mimetic drugs have geroprotective effects that delay or reduce risks for a variety of age-associated systemic diseases, suggesting that such drugs might also have the potential to reduce risks of blinding ophthalmologic conditions for which age is a major risk factor. OBJECTIVE To determine whether the caloric restriction mimetic drug metformin hydrochloride is associated with reduced risk of open-angle glaucoma (OAG) in persons with diabetes mellitus. DESIGN, SETTING, AND PATIENTS Retrospective cohort study of patients aged 40 years or older with diabetes mellitus and no preexisting record of OAG in a large US managed care network from January 1, 2001, through December 31, 2010. EXPOSURES Quantity of metformin and other prescribed diabetes medications as captured from outpatient pharmacy records. MAIN OUTCOMES AND MEASURES Risk of developing OAG. RESULTS Of 150 016 patients with diabetes mellitus, 5893 (3.9%) developed OAG. After adjusting for confounding factors, those prescribed the highest quartile of metformin hydrochloride (>1110 g in 2 years) had a 25% reduced OAG risk relative to those who took no metformin (hazard ratio = 0.75; 95% CI, 0.59-0.95; P = .02). Every 1-g increase in metformin hydrochloride use was associated with a 0.16% reduction in OAG risk (adjusted hazard ratio = 0.99984; 95% CI, 0.99969-0.99999; P = .04), which predicts that taking a standard dose of 2 g of metformin hydrochloride per day for 2 years would result in a 20.8% reduction in risk of OAG. After accounting for potential confounders, including metformin and diabetic medications, the risk of developing OAG was increased by 8% (hazard ratio = 1.08; 95% CI, 1.03-1.13; P = .003) for each unit of increase in glycated hemoglobin level. CONCLUSIONS AND RELEVANCE Metformin use is associated with reduction in risk of developing OAG, and risk is reduced even when accounting for glycemic control in the form of glycated hemoglobin level. Other diabetes medications did not confer a similar OAG risk reduction. This study suggests that metformin may be affecting OAG risk on multiple levels, some involving improved glycemic control and some involving mechanisms outside glycemic control such as neurogenesis, inflammatory systems, or longevity pathways targeted by caloric restriction mimetic drugs. If confirmed by prospective clinical trials, these findings could lead to novel treatments for this sight-threatening disease.
Collapse
Affiliation(s)
- Hsien-Chang Lin
- Department of Applied Health Science, Indiana University, Bloomington
| | - Joshua D Stein
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor3Institute for Health Care Policy and Innovation, University of Michigan, Ann Arbor
| | - Bin Nan
- Department of Biostatistics, University of Michigan, Ann Arbor
| | - David Childers
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor5Center for Statistical Consultation and Research, University of Michigan, Ann Arbor
| | - Paula Anne Newman-Casey
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor3Institute for Health Care Policy and Innovation, University of Michigan, Ann Arbor
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor6Department of Biological Chemistry, University of Michigan, Ann Arbor
| | | |
Collapse
|
25
|
Shelby SJ, Feathers KL, Ganios AM, Jia L, Miller JM, Thompson DA. MERTK signaling in the retinal pigment epithelium regulates the tyrosine phosphorylation of GDP dissociation inhibitor alpha from the GDI/CHM family of RAB GTPase effectors. Exp Eye Res 2015; 140:28-40. [PMID: 26283020 DOI: 10.1016/j.exer.2015.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 08/10/2015] [Accepted: 08/10/2015] [Indexed: 10/25/2022]
Abstract
Photoreceptor outer segments (OS) in the vertebrate retina undergo a process of continual renewal involving shedding of disc membranes that are cleared by phagocytic uptake into the retinal pigment epithelium (RPE). In dystrophic Royal College of Surgeons (RCS) rats, OS phagocytosis is blocked by a mutation in the gene encoding the receptor tyrosine kinase MERTK. To identify proteins tyrosine-phosphorylated downstream of MERTK in the RPE, MALDI-mass spectrometry with peptide-mass fingerprinting was used in comparative studies of RCS congenic and dystrophic rats. At times corresponding to peak phagocytic activity, the RAB GTPase effector GDP dissociation inhibitor alpha (GDI1) was found to undergo tyrosine phosphorylation only in congenic rats. In cryosections of native RPE/choroid, GDI1 colocalized with MERTK and the intracellular tyrosine-kinase SRC. In cultured RPE-J cells, and in transfected heterologous cells, MERTK stimulated SRC-mediated tyrosine phosphorylation of GDI1. In OS-fed RPE-J cells, GDI1 colocalized with MERTK and SRC on apparent phagosomes located near the apical membrane. In addition, both GDI1 and RAB5, a regulator of vesicular transport, colocalized with ingested OS. Taken together, these findings identify a novel role of MERTK signaling in membrane trafficking in the RPE that is likely to subserve mechanisms of phagosome formation.
Collapse
Affiliation(s)
- Shameka J Shelby
- Department of Biological Chemistry, University of Michigan Medical School, 1150 W. Medical Center Dr., Ann Arbor, MI 48109, USA; Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Kecia L Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Anna M Ganios
- Department of Biological Chemistry, University of Michigan Medical School, 1150 W. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Jason M Miller
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA
| | - Debra A Thompson
- Department of Biological Chemistry, University of Michigan Medical School, 1150 W. Medical Center Dr., Ann Arbor, MI 48109, USA; Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI 48105, USA.
| |
Collapse
|
26
|
Hull S, Kalhoro A, Marr J, Thompson DA, Holder GE, Robson AG, Moore AT. Congenital high myopia and central macular atrophy: a report of 3 families. Eye (Lond) 2015; 29:936-42. [PMID: 25998941 DOI: 10.1038/eye.2015.53] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 03/01/2015] [Indexed: 11/09/2022] Open
Abstract
AIMS To report the clinical phenotype in a series of four children from three families with the rare association of high myopia, central macular atrophy, and normal full-field electroretinography (ERG). METHODS Four male patients were ascertained with reduced vision, nystagmus, and atrophy of the macula from early childhood. Patients underwent full ophthalmic examination, electrophysiological testing, and retinal imaging. RESULTS Minimum duration of follow-up was 8 years. At last review, visual acuity ranged from 0.22 to 1.20 logMAR (6/9.5-6/95 Snellen) at a mean age of 10.5 years (median 9.5 years, range 9-14 years). Refractive error ranged from a spherical equivalent of -7.40 D to -24.00 D. Three had convergent squint. Fundus examination and imaging demonstrated bilateral macular atrophy in all patients that varied from mild atrophy of the retinal pigment epithelium (RPE) to well-demarcated, punched-out atrophic lesions of retina, RPE, and choroid. Flash ERG was normal under photopic and scotopic conditions in all patients. Pattern ERG, performed in three patients, was consistent with mild to severe macular dysfunction. Progression of the area of atrophy was evident in one patient and of the myopia in two patients but all patients had stable visual acuity. CONCLUSIONS Patients with congenital high myopia and macular atrophy present in infancy with reduced visual acuity and nystagmus. The macular atrophic lesions vary in size and severity but electrophysiological testing is consistent with dysfunction confined to the macula. There was no deterioration in visual acuity over 8-10 years of monitoring.
Collapse
Affiliation(s)
- S Hull
- 1] Inherited Eye Diseases, UCL Institute of Ophthalmology, London, UK [2] Moorfields Eye Hospital, London, UK
| | - A Kalhoro
- 1] Inherited Eye Diseases, UCL Institute of Ophthalmology, London, UK [2] Moorfields Eye Hospital, London, UK
| | - J Marr
- Department of Ophthalmology, Sheffield Children's Hospital, Sheffield, UK
| | - D A Thompson
- Department of Ophthalmology, Great Ormond Street Hospital, London, UK
| | - G E Holder
- 1] Inherited Eye Diseases, UCL Institute of Ophthalmology, London, UK [2] Moorfields Eye Hospital, London, UK
| | - A G Robson
- 1] Inherited Eye Diseases, UCL Institute of Ophthalmology, London, UK [2] Moorfields Eye Hospital, London, UK
| | - A T Moore
- 1] Inherited Eye Diseases, UCL Institute of Ophthalmology, London, UK [2] Moorfields Eye Hospital, London, UK [3] Department of Ophthalmology, Great Ormond Street Hospital, London, UK [4] Department of Ophthalmology, University of California, San Francisco, CA, USA
| |
Collapse
|
27
|
Bainbridge JWB, Mehat MS, Sundaram V, Robbie SJ, Barker SE, Ripamonti C, Georgiadis A, Mowat FM, Beattie SG, Gardner PJ, Feathers KL, Luong VA, Yzer S, Balaggan K, Viswanathan A, de Ravel TJL, Casteels I, Holder GE, Tyler N, Fitzke FW, Weleber RG, Nardini M, Moore AT, Thompson DA, Petersen-Jones SM, Michaelides M, van den Born LI, Stockman A, Smith AJ, Rubin G, Ali RR. Long-term effect of gene therapy on Leber's congenital amaurosis. N Engl J Med 2015; 372:1887-97. [PMID: 25938638 PMCID: PMC4497809 DOI: 10.1056/nejmoa1414221] [Citation(s) in RCA: 508] [Impact Index Per Article: 56.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Mutations in RPE65 cause Leber's congenital amaurosis, a progressive retinal degenerative disease that severely impairs sight in children. Gene therapy can result in modest improvements in night vision, but knowledge of its efficacy in humans is limited. METHODS We performed a phase 1-2 open-label trial involving 12 participants to evaluate the safety and efficacy of gene therapy with a recombinant adeno-associated virus 2/2 (rAAV2/2) vector carrying the RPE65 complementary DNA, and measured visual function over the course of 3 years. Four participants were administered a lower dose of the vector, and 8 were administered a higher dose. In a parallel study in dogs, we investigated the relationship among vector dose, visual function, and electroretinography (ERG) findings. RESULTS Improvements in retinal sensitivity were evident, to varying extents, in six participants for up to 3 years, peaking at 6 to 12 months after treatment and then declining. No associated improvement in retinal function was detected by means of ERG. Three participants had intraocular inflammation, and two had clinically significant deterioration of visual acuity. The reduction in central retinal thickness varied among participants. In dogs, RPE65 gene therapy with the same vector at lower doses improved vision-guided behavior, but only higher doses resulted in improvements in retinal function that were detectable with the use of ERG. CONCLUSIONS Gene therapy with rAAV2/2 RPE65 vector improved retinal sensitivity, albeit modestly and temporarily. Comparison with the results obtained in the dog model indicates that there is a species difference in the amount of RPE65 required to drive the visual cycle and that the demand for RPE65 in affected persons was not met to the extent required for a durable, robust effect. (Funded by the National Institute for Health Research and others; ClinicalTrials.gov number, NCT00643747.).
Collapse
Affiliation(s)
- James W B Bainbridge
- From the UCL (University College London) Institute of Ophthalmology (J.W.B.B., M.S.M., V.S., S.J.R., S.E.B., C.R., A.G., F.M.M., S.G.B., P.J.G., V.A.L., K.B., A.V., G.E.H., F.W.F., M.N., A.T.M., M.M., A.S., A.J.S., G.R., R.R.A.) and the Department of Civil, Environmental, and Geomatic Engineering (N.T.), UCL, and Moorfields Eye Hospital (J.W.B.B., M.S.M., V.S., S.J.R., A.G., K.B., G.H., A.M., M.M.), London, and the Department of Psychology, Durham University, Durham (M.N.) - all in the United Kingdom; the College of Veterinary Medicine, Michigan State University, East Lansing (F.M.M., S.M.P.-J.), and the Kellogg Eye Center, University of Michigan Medical School, Ann Arbor (K.L.F., D.A.T., R.R.A.); the Center for Human Genetics, KU Leuven (T.J.L.R.), and the Department of Ophthalmology, UZ Leuven, Campus Sint-Rafaël (I.C.) - both in Leuven, Belgium; Rotterdam Eye Hospital, Rotterdam, the Netherlands (S.Y., L.I.B.); and the Oregon Retinal Degeneration Center, Ophthalmic Genetics Service, Casey Eye Institute, Oregon Health and Science University, Portland (R.G.W.)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Hamilton R, Al Abdlseaed A, Healey J, Neveu MM, Brown L, Keating D, McBain VA, Sculfor D, Thompson DA. Multi-centre variability of ISCEV standard ERGs in two normal adults. Doc Ophthalmol 2015; 130:83-101. [PMID: 25720529 DOI: 10.1007/s10633-014-9471-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 11/12/2014] [Indexed: 10/23/2022]
Abstract
BACKGROUND The reproducibility of an individual's full-field ERG between centres has not previously been investigated. METHODS ERGs were recorded using both silver thread and skin electrodes from the same two normal adult subjects at 15 UK centres using routine, local protocols and a highly standardised, 'ISCEV-specified' protocol matching the values specified in the ISCEV standard; where the ISCEV standard allows options, a single value was chosen. RESULTS Inter-ocular differences were small, and amplitudes were smaller for skin than silver thread electrodes. No centre produced outlying data points, and ERGs across all 15 centres were remarkably similar. Amplitude variability was less for local protocols (using LED flashes) than for the ISCEV-specified protocol using xenon flashes (22 vs. 24 %, p = 0.01), but peak time variability was less for the ISCEV-specified protocol (6.1 vs. 7.4 %, p = 0.001). Only the DA 0.01 ERG correlated with photometric variability. The bifidity of the DA 3 a-wave doubled its peak time variability compared with the DA 10 a-wave. CONCLUSIONS Inter-centre amplitude variability was typically within clinically significant thresholds, suggesting that inter-centre variability with suitable standardisation may not add more to total variability than inter-subject variability. Variability improvements gained by the tighter specifications of the ISCEV-specified protocol were possibly more than lost due to imprecisions of xenon flashtubes. Peak time variability was far lower than amplitude variability, corresponding with acceptable variability of biochemical assays. These results represent a vindication of the existence of an ERG standard and suggest that further standardisation would lend itself to greater reproducibility of ERGs worldwide.
Collapse
Affiliation(s)
- R Hamilton
- Department of Clinical Physics, Royal Hospital for Sick Children, NHS Greater Glasgow and Clyde, University of Glasgow, Dalnair Street, Glasgow, G3 8SJ, UK,
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Thompson DA, Ali RR, Banin E, Branham KE, Flannery JG, Gamm DM, Hauswirth WW, Heckenlively JR, Iannaccone A, Jayasundera KT, Khan NW, Molday RS, Pennesi ME, Reh TA, Weleber RG, Zacks DN. Advancing therapeutic strategies for inherited retinal degeneration: recommendations from the Monaciano Symposium. Invest Ophthalmol Vis Sci 2015; 56:918-31. [PMID: 25667399 DOI: 10.1167/iovs.14-16049] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although rare in the general population, retinal dystrophies occupy a central position in current efforts to develop innovative therapies for blinding diseases. This status derives, in part, from the unique biology, accessibility, and function of the retina, as well as from the synergy between molecular discoveries and transformative advances in functional assessment and retinal imaging. The combination of these factors has fueled remarkable progress in the field, while at the same time creating complex challenges for organizing collective efforts aimed at advancing translational research. The present position paper outlines recent progress in gene therapy and cell therapy for this group of disorders, and presents a set of recommendations for addressing the challenges remaining for the coming decade. It is hoped that the formulation of these recommendations will stimulate discussions among researchers, funding agencies, industry, and policy makers that will accelerate the development of safe and effective treatments for retinal dystrophies and related diseases.
Collapse
Affiliation(s)
- Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Robin R Ali
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States Division of Molecular Therapy, University College London Institute of Ophthalmology, London, England, United Kingdom
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Kari E Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - John G Flannery
- Helen Wills Neuroscience Institute, University of California-Berkeley, Berkeley, California, United States
| | - David M Gamm
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Alessandro Iannaccone
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - K Thiran Jayasundera
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Naheed W Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Robert S Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mark E Pennesi
- Casey Eye Institute and the Department of Ophthalmology, Oregon Health and Science University, Portland, Oregon, United States
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, Washington, United States
| | - Richard G Weleber
- Casey Eye Institute and the Department of Ophthalmology, Oregon Health and Science University, Portland, Oregon, United States Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, United States
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | | |
Collapse
|
30
|
Han Y, Balkrishnan R, Thompson DA, Richards JE, Stein JD. Statin Medication Use and the Development of Proliferative Diabetic Retinopathy Among Patients with Type 2 Diabetes, Hypertension, and Hyperlipidemia. Value Health 2014; 17:A721. [PMID: 27202555 DOI: 10.1016/j.jval.2014.08.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Y Han
- University of Michigan, Ann Arbor, MI, USA
| | | | | | | | - J D Stein
- University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
31
|
Yao J, Jia L, Shelby SJ, Ganios AM, Feathers K, Thompson DA, Zacks DN. Circadian and noncircadian modulation of autophagy in photoreceptors and retinal pigment epithelium. Invest Ophthalmol Vis Sci 2014; 55:3237-46. [PMID: 24781939 DOI: 10.1167/iovs.13-13336] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Autophagy in photoreceptors and the RPE promotes homeostasis and survival. The purpose of this study is to determine the daily pattern of changes in autophagy and factors contributing to its regulation in the outer retina. METHODS Levels of autophagy markers in the retina and RPE were evaluated over a 24-hour period. To assess the role of phagocytosis in stimulating autophagy in the RPE, cultured RPE-J cells were incubated with isolated photoreceptor outer segments and levels of autophagy markers were measured. Electron microscopy was performed on retina sections and RPE-J cells to assess formation of double-membraned vesicles consistent with autophagosomes. RESULTS In wild-type C57BL/6 mice maintained under normal cycling light conditions, autophagy in photoreceptor cells and the RPE exhibited a bimodal pattern of activation. In photoreceptors, shifts between light and dark evoked a sharp decrease in autophagy that was followed by a time-dependent increase. In photoreceptors, translocation of transducin and arrestin from the outer to inner segment appeared to contribute to the light-dependent upregulation of autophagy. In contrast, the cyclic variations in RPE autophagy were independent of lighting conditions, and are triggered, at least in part, by ingestion of outer segments. CONCLUSIONS Activation of autophagy in the outer retina exhibits a bimodal pattern that correlates with shifts in transduction proteins within the photoreceptor and by circadian ingestion of outer segments in the RPE. These dynamic shifts suggest a critical role for this pathway in maintaining homeostasis, with further study needed to define the mechanisms underlying the regulation of this phenomenon.
Collapse
Affiliation(s)
- Jingyu Yao
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Shameka J Shelby
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Anna M Ganios
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Kecia Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States
| |
Collapse
|
32
|
Abstract
Molecular biology holds the promise not only of increasing our understanding of basic cell biology, but also of advancing our ability to design targeted therapeutic methods for treating a range of diseases. One example that seems to hold tremendous potential is gene therapy, the use of exogenous DNA to replace or suppress a mutant gene in the patient's genome, or to boost the activity of a normal gene. A recent report (highlighted in a punctum in this issue of the journal) has brought autophagy into the gene therapy realm.
Collapse
Affiliation(s)
- Debra A Thompson
- Department of Ophthalmology and Visual Sciences and Department of Biological Chemistry; University of Michigan; Ann Arbor, MI USA
| | | |
Collapse
|
33
|
Shelby SJ, Colwill K, Dhe-Paganon S, Pawson T, Thompson DA. MERTK interactions with SH2-domain proteins in the retinal pigment epithelium. PLoS One 2013; 8:e53964. [PMID: 23390493 PMCID: PMC3563642 DOI: 10.1371/journal.pone.0053964] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 12/05/2012] [Indexed: 11/18/2022] Open
Abstract
The receptor tyrosine kinase MERTK plays an essential role in the phagocytic uptake of shed photoreceptor membranes by the retinal pigment epithelium (RPE). A fundamental aspect of signal transduction by receptor tyrosine kinases involves autophosphorylation of tyrosine residues that recruit Src-homology 2 (SH2)-domain proteins to the receptor intracellular domain. The goal of the current study was to evaluate the interactions of human MERTK with SH2-domain proteins present in the RPE. The MERTK intracellular domain was expressed as a 6xHis-fusion protein (6xHis-rMERTK(571-999)), purified and phosphorylated. Ni(2+)-NTA pull downs were performed using 6xHis-rMERTK(571-999) in incubations with recombinant phosphotyrosine-recognition sequences expressed as GST-fusion proteins. In addition, pull downs of native SH2-domain proteins were performed using 6xHis-rMERTK(571-999) and protein homogenates from rat RPE/choroid. For both recombinant and native proteins, western analysis detected MERTK interactions with GRB2, PIK3R1 (P85α), VAV3, and SRC. Immunohistochemical analysis localized each protein to mouse RPE. In cultured RPE-J cells incubated with rod outer segments (OS), siRNA knockdown of Grb2 had no effect on OS binding, but significantly reduced OS uptake. Pik3r1 localized to early phagosomes along with Rab5 and Eea1. Phosphorylation and activation of Src was detected downstream of phagocytosis and Mertk activation. These findings suggest that MERTK signaling in the RPE involves a cohort of SH2-domain proteins with the potential to regulate both cytoskeletal rearrangement and membrane movement. Identification of the SH2-domain signaling partners of MERTK is an important step toward further defining the mechanism of RPE phagocytosis that is central to the function and survival of the retina.
Collapse
Affiliation(s)
- Shameka J. Shelby
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Karen Colwill
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Sirano Dhe-Paganon
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Tony Pawson
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Medical Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Debra A. Thompson
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
34
|
Chen C, Thompson DA, Koutalos Y. Reduction of all-trans-retinal in vertebrate rod photoreceptors requires the combined action of RDH8 and RDH12. J Biol Chem 2012; 287:24662-70. [PMID: 22621924 DOI: 10.1074/jbc.m112.354514] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In vertebrate rod cells, retinoid dehydrogenases/reductases (RDHs) are critical for reducing the reactive aldehyde all-trans-retinal that is released by photoactivated rhodopsin, to all-trans-retinol (vitamin A). Previous studies have shown that RDH8 localizes to photoreceptor outer segments and is a strong candidate for performing this role. However, RDH12 function in the photoreceptor inner segments is also key, because loss of function mutations cause retinal degeneration in some forms of Leber congenital amaurosis. To investigate the in vivo roles of RDH8 and RDH12, we used fluorescence imaging to examine all-trans-retinol production in single isolated rod cells from wild-type mice and knock-out mice lacking either one or both RDHs. Outer segments of rods deficient in Rdh8 failed to reduce all-trans-retinal, but those deficient in Rdh12 were unaffected. Following exposure to light, a leak of retinoids from outer to inner segments was detected in rods from both wild-type and knock-out mice. In cells lacking Rdh8 or Rdh12, this leak was mainly all-trans-retinal. Wild-type rods incubated with all-trans-retinal reduced moderate loads of retinal within the cell interior, but this ability was lost by cells deficient in Rdh8 or Rdh12. Our findings are consistent with localization of RDH8 to the outer segment where it provides most of the activity needed to reduce all-trans-retinal generated by the light response. In contrast, RDH12 in inner segments can protect vital cell organelles against aldehyde toxicity caused by an intracellular leak of all-trans-retinal, as well as other aldehydes originating both inside and outside the cell.
Collapse
Affiliation(s)
- Chunhe Chen
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
| | | | | |
Collapse
|
35
|
Thompson DA, Khan NW, Othman MI, Chang B, Jia L, Grahek G, Wu Z, Hiriyanna S, Nellissery J, Li T, Khanna H, Colosi P, Swaroop A, Heckenlively JR. Rd9 is a naturally occurring mouse model of a common form of retinitis pigmentosa caused by mutations in RPGR-ORF15. PLoS One 2012; 7:e35865. [PMID: 22563472 PMCID: PMC3341386 DOI: 10.1371/journal.pone.0035865] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 03/27/2012] [Indexed: 11/18/2022] Open
Abstract
Animal models of human disease are an invaluable component of studies aimed at understanding disease pathogenesis and therapeutic possibilities. Mutations in the gene encoding retinitis pigmentosa GTPase regulator (RPGR) are the most common cause of X-linked retinitis pigmentosa (XLRP) and are estimated to cause 20% of all retinal dystrophy cases. A majority of RPGR mutations are present in ORF15, the purine-rich terminal exon of the predominant splice-variant expressed in retina. Here we describe the genetic and phenotypic characterization of the retinal degeneration 9 (Rd9) strain of mice, a naturally occurring animal model of XLRP. Rd9 mice were found to carry a 32-base-pair duplication within ORF15 that causes a shift in the reading frame that introduces a premature-stop codon. Rpgr ORF15 transcripts, but not protein, were detected in retinas from Rd9/Y male mice that exhibited retinal pathology, including pigment loss and slowly progressing decrease in outer nuclear layer thickness. The levels of rhodopsin and transducin in rod outer segments were also decreased, and M-cone opsin appeared mislocalized within cone photoreceptors. In addition, electroretinogram (ERG) a- and b-wave amplitudes of both Rd9/Y male and Rd9/Rd9 female mice showed moderate gradual reduction that continued to 24 months of age. The presence of multiple retinal features that correlate with findings in individuals with XLRP identifies Rd9 as a valuable model for use in gaining insight into ORF15-associated disease progression and pathogenesis, as well as accelerating the development and testing of therapeutic strategies for this common form of retinal dystrophy.
Collapse
Affiliation(s)
- Debra A. Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Naheed W. Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Mohammad I. Othman
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Bo Chang
- Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Garrett Grahek
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Zhijian Wu
- Neurobiology-Neurodegeneration & Repair laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Suja Hiriyanna
- Neurobiology-Neurodegeneration & Repair laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jacob Nellissery
- Neurobiology-Neurodegeneration & Repair laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tiansen Li
- Neurobiology-Neurodegeneration & Repair laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hemant Khanna
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Peter Colosi
- Neurobiology-Neurodegeneration & Repair laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (AS); (JRH)
| | - John R. Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail: (AS); (JRH)
| |
Collapse
|
36
|
Gearhart PM, Gearhart C, Thompson DA, Petersen-Jones SM. Improvement of visual performance with intravitreal administration of 9-cis-retinal in Rpe65-mutant dogs. ACTA ACUST UNITED AC 2010; 128:1442-8. [PMID: 20837787 DOI: 10.1001/archophthalmol.2010.210] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To determine the efficacy of intravitreal administration of 9-cis-retinal in restoring visual function in Rpe65-mutant dogs. METHODS Intravitreal injection of 9-cis-retinal was administered in 1 eye of 7 Rpe65-/- dogs at a range of ages. Electroretinogram analysis and testing of visual performance was used to evaluate outcomes after a single injection and in 2 dogs after a second injection in the same eye. RESULTS In 5 of 7 injected dogs, 9-cis-retinal injection resulted in increased rod electroretinogram responses and improved functional vision. Three injected dogs exhibited increased 33-Hz flicker amplitudes characteristic of cone-mediated responses. Electroretinogram improvement was no longer evident by week 10 postinjection in 1 dog monitored over time. A second injection of 9-cis-retinal was performed in the same eye of 2 of the 7 dogs and also resulted in rescue of visual function. CONCLUSION Our findings establish that 9-cis-retinoid therapy can restore visual function in a canine model of human disease resulting from RPE65 mutations. CLINICAL RELEVANCE These positive proof-of-principle results provide support for the development of intravitreal devices for sustained delivery of 9-cis-retinal as a therapy for conditions resulting from failure of the visual cycle.
Collapse
Affiliation(s)
- Patricia M Gearhart
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | |
Collapse
|
37
|
Czaban JA, Thompson DA. Semiconductor optical amplifiers grown on a metamorphic substrate for long wavelength applications. Nanotechnology 2010; 21:134005. [PMID: 20208114 DOI: 10.1088/0957-4484/21/13/134005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A semiconductor optical amplifier is grown on an InAsP metamorphic substrate to extend the long wavelength accessibility of the amplifier. The amplifier is shown to produce gain at wavelength exceeding 1640 nm while containing large tensile strain in the quantum wells. Also a laser diode is fabricated from the same device structure.
Collapse
Affiliation(s)
- J A Czaban
- Engineering Physics McMaster University, Hamilton, ON, Canada
| | | |
Collapse
|
38
|
Caram J, Sandoval C, Tirado M, Comedi D, Czaban J, Thompson DA, LaPierre RR. Electrical characteristics of core-shell p-n GaAs nanowire structures with Te as the n-dopant. Nanotechnology 2010; 21:134007. [PMID: 20208111 DOI: 10.1088/0957-4484/21/13/134007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
GaAs nanowire (NW)-based p-n photovoltaic devices, with two distinct p and n spatial distributions and where Te was the n-dopant, have been studied by impedance spectroscopy in the 10(3)-10(7) Hz frequency range and the - 1.5-1.5 V bias range. For a large n-core/p-shell overlap region within NWs in a coaxial geometry, the p-n junction properties (DC rectification and p-n depletion capacitance) are found to prevail. The impedance data at low bias for both NW devices show large frequency dispersions with relaxation frequencies that are compatible with carrier re-emission times from traps due to GaAs surface states. An increasing conductance with increasing frequency for low bias is observed, suggesting hopping transport through localized states. For large bias the conductance increases exponentially with bias and is frequency independent, indicating conduction through extended states in this regime.
Collapse
Affiliation(s)
- J Caram
- Laboratorio de Física del Sólido, Departamento de Física, FACET, Universidad Nacional de Tucumán, Tucumán, Argentina
| | | | | | | | | | | | | |
Collapse
|
39
|
Marchette LD, Thompson DA, Kravtsova M, Ngansop TN, Mandal MNA, Kasus-Jacobi A. Retinol dehydrogenase 12 detoxifies 4-hydroxynonenal in photoreceptor cells. Free Radic Biol Med 2010; 48:16-25. [PMID: 19686838 PMCID: PMC2874966 DOI: 10.1016/j.freeradbiomed.2009.08.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 07/15/2009] [Accepted: 08/10/2009] [Indexed: 11/18/2022]
Abstract
Mutations of the photoreceptor retinol dehydrogenase 12 (RDH12) gene cause the early onset retinal dystrophy Leber congenital amaurosis (LCA) by mechanisms not completely resolved. Determining the physiological role of RDH12 in photoreceptors is the focus of this study. Previous studies showed that RDH12, and the closely related retinol dehydrogenase RDH11, can enzymatically reduce toxic lipid peroxidation products such as 4-hydroxynonenal (4-HNE), in vitro. To explore the significance of this activity, we investigated the ability of RDH11 and RDH12 to protect stably transfected HEK-293 cells against the toxicity of 4-HNE. Both enzymes protected against 4-HNE modification of proteins and 4-HNE-induced apoptosis in HEK-293 cells. In the retina, exposure to bright light induced lipid peroxidation, 4-HNE production, and 4-HNE modification of proteins in photoreceptor inner segments, where RDH11 and RDH12 are located. In mouse retina, RDH12-but not RDH11-protected against adduct formation, suggesting that 4-HNE is a physiological substrate of RDH12. RDH12-but not RDH11-also protected against light-induced apoptosis of photoreceptors. We conclude that in mouse retina RDH12 reduces 4-HNE to a nontoxic alcohol, protecting cellular macromolecules against oxidative modification and protecting photoreceptors from light-induced apoptosis. This activity is of particular significance to the understanding of the molecular mechanisms of RDH12-induced LCA.
Collapse
Affiliation(s)
- Lea D. Marchette
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Debra A. Thompson
- Departments of Ophthalmology and Visual Sciences, and Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48105, USA
| | - Marina Kravtsova
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Thierry N. Ngansop
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Md Nawajes A. Mandal
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Anne Kasus-Jacobi
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| |
Collapse
|
40
|
Chrispell JD, Feathers KL, Kane MA, Kim CY, Brooks M, Khanna R, Kurth I, Hübner CA, Gal A, Mears AJ, Swaroop A, Napoli JL, Sparrow JR, Thompson DA. Rdh12 activity and effects on retinoid processing in the murine retina. J Biol Chem 2009; 284:21468-77. [PMID: 19506076 PMCID: PMC2755871 DOI: 10.1074/jbc.m109.020966] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 06/04/2009] [Indexed: 11/06/2022] Open
Abstract
RDH12 mutations are responsible for early-onset autosomal recessive retinal dystrophy, which results in profound retinal pathology and severe visual handicap in patients. To investigate the function of RDH12 within the network of retinoid dehydrogenases/reductases (RDHs) present in retina, we studied the retinal phenotype of Rdh12-deficient mice. In vivo rates of all-trans-retinal reduction and 11-cis-retinal formation during recovery from bleaching were similar in Rdh12-deficient and wild-type mice matched for an Rpe65 polymorphism that impacts visual cycle efficiency. However, retinal homogenates from Rdh12-deficient mice exhibited markedly decreased capacity to reduce exogenous retinaldehydes in vitro. Furthermore, in vivo levels of the bisretinoid compound diretinoid-pyridinium-ethanolamine (A2E) were increased in Rdh12-deficient mice of various genetic backgrounds. Conversely, in vivo levels of retinoic acid and total retinol were significantly decreased. Rdh12 transcript levels in wild-type mice homozygous for the Rpe65-Leu(450) polymorphism were greater than in Rpe65-Met(450) mice and increased during postnatal development in wild-type mice and Nrl-deficient mice having an all-cone retina. Rdh12-deficient mice did not exhibit increased retinal degeneration relative to wild-type mice at advanced ages, when bred on the light-sensitive BALB/c background, or when heterozygous for a null allele of superoxide dismutase 2 (Sod2(+/-)). Our findings suggest that a critical function of RDH12 is the reduction of all-trans-retinal that exceeds the reductive capacity of the photoreceptor outer segments.
Collapse
Affiliation(s)
| | - Kecia L. Feathers
- Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Maureen A. Kane
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720
| | - Chul Y. Kim
- Departments of Ophthalmology and Pathology and Cell Biology, Columbia University, New York, New York 10032
| | - Matthew Brooks
- Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan 48105
- Neurobiology-Neurodegeneration and Repair Laboratory, NEI, National Institutes of Health, Bethesda, Maryland 20892
| | - Ritu Khanna
- Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Ingo Kurth
- Institute of Human Genetics, University of Hamburg-Eppendorf, D-20251 Hamburg, Germany
| | - Christian A. Hübner
- Department of Clinical Chemistry, Friedrich-Schiller-Universität, D-07747 Jena, Germany
| | - Andreas Gal
- Institute of Human Genetics, University of Hamburg-Eppendorf, D-20251 Hamburg, Germany
| | - Alan J. Mears
- Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan 48105
- University of Ottawa Eye Institute and Ottawa Health Research Institute, Ottawa, Ontario K1Y 4E9, Canada, and
| | - Anand Swaroop
- Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan 48105
- Neurobiology-Neurodegeneration and Repair Laboratory, NEI, National Institutes of Health, Bethesda, Maryland 20892
| | - Joseph L. Napoli
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720
| | - Janet R. Sparrow
- Departments of Ophthalmology and Pathology and Cell Biology, Columbia University, New York, New York 10032
| | - Debra A. Thompson
- From the Departments of Biological Chemistry and
- Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan 48105
| |
Collapse
|
41
|
Huang X, Finerty P, Walker JR, Butler-Cole C, Vedadi M, Schapira M, Parker SA, Turk BE, Thompson DA, Dhe-Paganon S. Structural insights into the inhibited states of the Mer receptor tyrosine kinase. J Struct Biol 2008; 165:88-96. [PMID: 19028587 PMCID: PMC2686088 DOI: 10.1016/j.jsb.2008.10.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2008] [Revised: 10/19/2008] [Accepted: 10/20/2008] [Indexed: 01/12/2023]
Abstract
The mammalian ortholog of the retroviral oncogene v-Eyk, and a receptor tyrosine kinase upstream of antiapoptotic and transforming signals, Mer (MerTK) is a mediator of the phagocytic process, being involved in retinal and immune cell clearance and platelet aggregation. Mer knockout mice are viable and are protected from epinephrine-induced pulmonary thromboembolism and ferric chloride-induced thrombosis. Mer overexpression, on the other hand, is associated with numerous carcinomas. Although Mer adaptor proteins and signaling pathways have been identified, it remains unclear how Mer initiates phagocytosis. When bound to its nucleotide cofactor, the high-resolution structure of Mer shows an autoinhibited αC-Glu-out conformation with insertion of an activation loop residue into the active site. Mer complexed with compound-52 (C52: 2-(2-hydroxyethylamino)-6-(3-chloroanilino)-9-isopropylpurine), a ligand identified from a focused library, retains its DFG-Asp-in and αC-Glu-out conformation, but acquires other conformational changes. The αC helix and DFGL region is closer to the hinge region and the ethanolamine moiety of C52 binds in the groove formed between Leu593 and Val601 of the P-loop, causing a compression of the active site pocket. These conformational states reveal the mechanisms of autoinhibition, the pathophysiological basis of disease-causing mutations, and a platform for the development of chemical probes.
Collapse
Affiliation(s)
- Xudong Huang
- Structural Genomics Consortium, University of Toronto, Toronto, Ont., Canada
- Department of Physiology, University of Toronto, Toronto, Ont., Canada
| | - Patrick Finerty
- Structural Genomics Consortium, University of Toronto, Toronto, Ont., Canada
| | - John R. Walker
- Structural Genomics Consortium, University of Toronto, Toronto, Ont., Canada
| | | | - Masoud Vedadi
- Structural Genomics Consortium, University of Toronto, Toronto, Ont., Canada
| | - Matthieu Schapira
- Structural Genomics Consortium, University of Toronto, Toronto, Ont., Canada
- Department of Pharmacology, University of Toronto, Toronto, Ont., Canada
| | - Sirlester A. Parker
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Benjamin E. Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Debra A. Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, W.K. Kellogg Eye Center, Ann Arbor, MI 48105-0714, USA
- Department of Biological Chemistry, University of Michigan Medical School, W.K. Kellogg Eye Center, Ann Arbor, MI 48105-0714, USA
| | - Sirano Dhe-Paganon
- Structural Genomics Consortium, University of Toronto, Toronto, Ont., Canada
- Department of Physiology, University of Toronto, Toronto, Ont., Canada
- Corresponding author. Address: Banting & Best Institute, University of Toronto, 100 College Street, Room 511, Toronto, Ont., Canada M5G 1L5. Fax: +1 416 946 0588.
| |
Collapse
|
42
|
Feathers KL, Lyubarsky AL, Khan NW, Teofilo K, Swaroop A, Williams DS, Pugh EN, Thompson DA. Nrl-knockout mice deficient in Rpe65 fail to synthesize 11-cis retinal and cone outer segments. Invest Ophthalmol Vis Sci 2008; 49:1126-35. [PMID: 18326740 DOI: 10.1167/iovs.07-1234] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To define rod and cone function further in terms of visual cycle mechanism, the retinal phenotype resulting from Rpe65 (retinoid isomerase I) deficiency in Nrl(-)(/)(-) mice having a single class of photoreceptors resembling wild-type cones was characterized and outcomes of retinoid supplementation evaluated. METHODS Rpe65(-)(/)(-)/Nrl(-)(/)(-) mice were generated by breeding Rpe65(-)(/)(-) and Nrl(-)(/)(-) strains. Retinal histology, protein expression, retinoid content, and electroretinographic (ERG) responses were evaluated before and after treatment with 11-cis retinal by intraperitoneal injection. Results Retinas of young Rpe65(-)(/-)/Nrl(-)(/-) mice exhibited normal lamination, but lacked intact photoreceptor outer segments at all ages examined. Rpe65, Nrl, and rhodopsin were not detected, and S-opsin and M/L-opsin levels were reduced. Retinyl esters were the only retinoids present. In contrast, Nrl(-)(/)(-) mice exhibited decreased levels of retinaldehydes and retinyl esters, and elevated levels of retinols. ERG responses were elicited from Rpe65(-)(/-)/Nrl(-)(/-) mice only at the two highest intensities over a 4-log-unit range. Significant retinal thinning and outer nuclear layer loss occurred in Rpe65(-)(/-)/Nrl(-)(/-) mice with aging. Administration of exogenous 11-cis retinal did not rescue retinal morphology or markedly improve ERG responses. CONCLUSIONS The findings provide clarification of reported cone loss of function in Rpe65(-)(/-)/Nrl(-)(/-) mice, now showing that chromophore absence results in destabilized cone outer segments and rapid retinal degeneration. The data support the view that rod-dominant retinas do not have a cone-specific mechanism for 11-cis retinal synthesis and have potential significance for therapeutic strategies for rescue of cone-rich retinal regions affected by disease in the aging human population.
Collapse
Affiliation(s)
- Kecia L Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan 48105, USA
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Schuster A, Janecke AR, Wilke R, Schmid E, Thompson DA, Utermann G, Wissinger B, Zrenner E, Gal A. The Phenotype of Early-Onset Retinal Degeneration in Persons withRDH12Mutations. ACTA ACUST UNITED AC 2007; 48:1824-31. [PMID: 17389517 DOI: 10.1167/iovs.06-0628] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
PURPOSE To describe the retinal dystrophy phenotype associated with mutations in RDH12, the gene encoding a retinoid dehydrogenase/reductase expressed in the photoreceptor cells. METHODS Sixteen persons from 12 families with pathogenic RDH12 mutations on both alleles were studied. Retinal phenotypes were characterized by ophthalmic examination, including psychophysical and standardized electrophysiological methods and multifocal electroretinography (mfERG). RESULTS The retinal disease in persons with RDH12 mutations in the homozygous (p.G127X, p.Q189X, p.Y226C, p.A269GfsX1, and p.L274P) or compound heterozygous state (p.R65X/p.A269GfsX1, p.H151D/p.T155I, p.H151D/p.A269GfsX1) was diagnosed initially as Leber congenital amaurosis (LCA) or early-onset retinitis pigmentosa. These individuals appeared to share a common clinical picture, independent of the type of mutation, characterized by poor, yet useful visual function in early life, followed by progressive decline due to both rod and cone degeneration. Marked pigmentary retinopathy, including bone spicules in the peripheral retina, was present in all persons older than age 6, and pronounced maculopathy was evident in persons older than 7 years. A unique view into the progressive nature of the disorder was achieved by evaluation of seven affected persons from three consanguineous families, all carrying the homozygous p.Y226C mutation. CONCLUSIONS Ophthalmic findings in persons with RDH12 mutations suggest that RDH12 loss-of-function results in a characteristic form of early and progressive rod-cone degeneration distinct from that caused by mutations in other LCA genes. From our data, it seems likely that various clinical designations appropriately describe the diagnosis in these persons, including early-onset retinitis pigmentosa, LCA type II, and childhood retinal dystrophy.
Collapse
Affiliation(s)
- Andreas Schuster
- Department of Pathophysiology of Vision and Neuroophthalmology, University Eye Hospital, Schleichstrasse 12-16, D-72076 Tübingen, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Jacobson SG, Cideciyan AV, Aleman TS, Sumaroka A, Schwartz SB, Windsor EAM, Roman AJ, Heon E, Stone EM, Thompson DA. RDH12 and RPE65, visual cycle genes causing leber congenital amaurosis, differ in disease expression. Invest Ophthalmol Vis Sci 2007; 48:332-8. [PMID: 17197551 DOI: 10.1167/iovs.06-0599] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Human blindness caused by mutation of visual cycle genes has been discussed as potentially treatable by retinoid replacement either through gene transfer or pharmacological bypass. Mutations in the RDH12 gene disrupt the visual cycle in vitro, but little is known of the in vivo effects of mutant RDH12, other than the association with severe early-onset autosomal recessive retinal disease. The relationship of retinal organization and visual function in patients with RDH12 mutations was determined and comparisons made with the disease from mutations in another visual cycle gene, RPE65. METHODS Young patients with RDH12 mutations were studied with optical coherence tomography (OCT) and colocalized measures of vision with dark-adapted absolute thresholds. Results were compared to those in patients with RPE65 mutations. RESULTS Retinal architecture of patients with RDH12 mutations was appreciably distorted, precluding identification of the normal laminae. Some RDH12-mutant retinas were remarkably thick and others were thin, but all had the same dysplastic pattern. A comparison with the structural and functional consequences in patients with mutations in RPE65 indicated that the pathogenesis of retinal degeneration in RDH12 mutations was distinctly different. CONCLUSIONS The results demand critical consideration of the human disease mechanism and the therapeutic approach in patients with mutations in the putative visual cycle gene RDH12.
Collapse
Affiliation(s)
- Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Friedman JS, Chang B, Kannabiran C, Chakarova C, Singh HP, Jalali S, Hawes NL, Branham K, Othman M, Filippova E, Thompson DA, Webster AR, Andréasson S, Jacobson SG, Bhattacharya SS, Heckenlively JR, Swaroop A. Premature truncation of a novel protein, RD3, exhibiting subnuclear localization is associated with retinal degeneration. Am J Hum Genet 2006; 79:1059-70. [PMID: 17186464 PMCID: PMC1698706 DOI: 10.1086/510021] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Accepted: 10/06/2006] [Indexed: 01/03/2023] Open
Abstract
The rd3 mouse is one of the oldest identified models of early-onset retinal degeneration. Using the positional candidate approach, we have identified a C-->T substitution in a novel gene, Rd3, that encodes an evolutionarily conserved protein of 195 amino acids. The rd3 mutation results in a predicted stop codon after residue 106. This change is observed in four rd3 lines derived from the original collected mice but not in the nine wild-type mouse strains that were examined. Rd3 is preferentially expressed in the retina and exhibits increasing expression through early postnatal development. In transiently transfected COS-1 cells, the RD3-fusion protein shows subnuclear localization adjacent to promyelocytic leukemia-gene-product bodies. The truncated mutant RD3 protein is detectable in COS-1 cells but appears to get degraded rapidly. To explore potential association of the human RD3 gene at chromosome 1q32 with retinopathies, we performed a mutation screen of 881 probands from North America, India, and Europe. In addition to several alterations of uncertain significance, we identified a homozygous alteration in the invariant G nucleotide of the RD3 exon 2 donor splice site in two siblings with Leber congenital amaurosis. This mutation is predicted to result in premature truncation of the RD3 protein, segregates with the disease, and is not detected in 121 ethnically matched control individuals. We suggest that the retinopathy-associated RD3 protein is part of subnuclear protein complexes involved in diverse processes, such as transcription and splicing.
Collapse
Affiliation(s)
- James S Friedman
- Department of Ophthalmology, W. K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Kurth I, Thompson DA, Rüther K, Feathers KL, Chrispell JD, Schroth J, McHenry CL, Schweizer M, Skosyrski S, Gal A, Hübner CA. Targeted disruption of the murine retinal dehydrogenase gene Rdh12 does not limit visual cycle function. Mol Cell Biol 2006; 27:1370-9. [PMID: 17130236 PMCID: PMC1800705 DOI: 10.1128/mcb.01486-06] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RDH12 codes for a member of the family of short-chain alcohol dehydrogenases/reductases proposed to function in the visual cycle that supplies the chromophore 11-cis retinal to photoreceptor cells. Mutations in RDH12 cause severe and progressive childhood onset autosomal-recessive retinal dystrophy, including Leber congenital amaurosis. We generated Rdh12 knockout mice, which exhibited grossly normal retinal histology at 10 months of age. Levels of all-trans and 11-cis retinoids in dark- and light-adapted animals and scotopic and photopic electroretinogram (ERG) responses were similar to those for the wild type, as was recovery of the ERG response following bleaching, for animals matched for an Rpe65 polymorphism (p.L450M). Lipid peroxidation products and other measures of oxidative stress did not appear to be elevated in Rdh12(-/-) animals. RDH12 was localized to photoreceptor inner segments and the outer nuclear layer in both mouse and human retinas by immunohistochemistry. The present findings, together with those of earlier studies showing only minor functional deficits in mice deficient for Rdh5, Rdh8, or Rdh11, suggest that the activity of any one isoform is not rate limiting in the visual response.
Collapse
Affiliation(s)
- Ingo Kurth
- Institut für Humangenetik, Universitätsklinikum Hamburg-Eppendorf, Butenfeld 42, 22529 Hamburg, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Sexton JB, Holzmueller CG, Pronovost PJ, Thomas EJ, McFerran S, Nunes J, Thompson DA, Knight AP, Penning DH, Fox HE. Variation in caregiver perceptions of teamwork climate in labor and delivery units. J Perinatol 2006; 26:463-70. [PMID: 16775621 DOI: 10.1038/sj.jp.7211556] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To test the psychometric soundness of a teamwork climate survey in labor and delivery, examine differences in perceptions of teamwork, and provide benchmarking data. DESIGN Cross-sectional survey of labor and delivery caregivers in 44 hospitals in diverse regions of the US, using the Safety Attitudes Questionnaire teamwork climate scale. RESULTS The response rate was 72% (3382 of 4700). The teamwork climate scale had good internal reliability (overall alpha = 0.78). Teamwork climate scale factor structure was confirmed using multilevel confirmatory factor analyses (CFI = 0.95, TLI = 0.92, RMSEA = 0.12, SRMR(within) = 0.04, SRMR(between) = 0.09). Aggregation of individual-level responses to the L&D unit-level was supported by ICC (1) = 0.06 (P < 0.001), ICC (2) = 0.83 and mean r (wg(j)) = 0.83. ANOVA demonstrated differences between caregivers F (7, 3013) = 10.30, P < 0.001 and labor and delivery units, F (43, 1022) = 3.49, P < 0.001. Convergent validity of the scale scores was measured by correlations with external teamwork-related items: collaborative decision making (r = 0.780, P < 0.001), use of briefings (r = 0.496, P < 0.001) and perceived adequacy of staffing levels (r = 0.593, P < 0.001). CONCLUSION We demonstrate a psychometrically sound teamwork climate scale, correlate it to external teamwork-related items, and provide labor and delivery teamwork benchmarks. Further teamwork climate research should explore the links to clinical and operational outcomes.
Collapse
Affiliation(s)
- J B Sexton
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore, MD, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Thompson DA, Janecke AR, Lange J, Feathers KL, Hübner CA, McHenry CL, Stockton DW, Rammesmayer G, Lupski JR, Antinolo G, Ayuso C, Baiget M, Gouras P, Heckenlively JR, den Hollander A, Jacobson SG, Lewis RA, Sieving PA, Wissinger B, Yzer S, Zrenner E, Utermann G, Gal A. Retinal degeneration associated with RDH12 mutations results from decreased 11-cis retinal synthesis due to disruption of the visual cycle. Hum Mol Genet 2006. [DOI: 10.1093/hmg/ddl079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
49
|
Hemati N, Feathers KL, Chrispell JD, Reed DM, Carlson TJ, Thompson DA. RPE65 surface epitopes, protein interactions, and expression in rod- and cone-dominant species. Mol Vis 2005; 11:1151-65. [PMID: 16379027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
PURPOSE RPE65 is an abundant protein necessary for the synthesis of the chromophore 11-cis retinal by the retinal pigment epithelium (RPE). Our purpose was to identify RPE65 surface epitopes, to assess protein interactions, and to evaluate RPE65 expression in eyes from rod- and cone-dominant species using a monoclonal antibody approach. METHODS RPE65-specific monoclonal antibodies, mAb 8B11, and mAb 1F9, were generated using bovine RPE microsomal membranes and a human RPE65 synthetic peptide as immunogen, respectively. Western analysis was performed on bovine RPE membranes, as well as yeast strains generated by transfection with RPE65 cDNAs. Competition of antibody binding by synthetic peptides was assayed using ELISAs, western analysis, and elution from immunoaffinity matrices. RPE65 structural models were generated by ab initio and comparative methods. Immunohistochemistry was performed on retina/RPE/choroid cryosections and retina flatmounts. RESULTS The antigenic determinant recognized by mAb 8B11 was localized to a 10 amino acid sequence, KVNPETLETI, that competed binding with microM affinity and eluted RPE65 from an immunoaffinity matrix incubated with solubilized bovine RPE membranes or RPE65-transfected cells. Similarly, solubilized RPE65 was bound and eluted from an mAb 1F9 immunoaffinity matrix using the immunizing peptide, FHHINTYEDNGFLIV. In both cases, 11-cis retinol dehydrogenase, but not other known visual cycle proteins, appeared to co-elute with RPE65 in substoichiometric amounts. Both sequences localized to surface exposed regions of predicted RPE65 tertiary structures. RPE65 immunoreactivity was detected by mAb 8B11 and mAb 1F9 in the RPE, but not in retina, in bovine, rat, mouse, human, chicken, and Xenopus laevis, and in Nrl knockout mice whose retinas contain exclusively cone-like photoreceptor cells. CONCLUSIONS The identification of RPE65 surface exposed antigenic determinants represents a first step toward understanding RPE65 structure and its interaction with visual cycle proteins, and provides a means for the purification of the native protein. The finding that RPE65 immunoreactivity is present in the RPE and not retina of both rod- and cone-dominant species does not support a proposed direct role for RPE65 in cone cell function.
Collapse
Affiliation(s)
- Nahid Hemati
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, MI 48105, USA
| | | | | | | | | | | |
Collapse
|
50
|
Sami DA, Saunders D, Thompson DA, Russell-Eggitt IM, Nischal KK, Jeffrey G, Jeffery G, Dattani M, Clement RA, Liasis A, Liassis A, Taylor DS. The achiasmia spectrum: congenitally reduced chiasmal decussation. Br J Ophthalmol 2005; 89:1311-7. [PMID: 16170123 PMCID: PMC1772901 DOI: 10.1136/bjo.2005.068171] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To describe the clinical spectrum of achiasmia, a congenital disorder of reduced relative decussation at the optic chiasm. METHODS A retrospective case note and patient review of nine children (four boys). Achiasmia was defined by the combination of a characteristic asymmetry of the monocular visual evoked potential (VEP) response to flash and neuroimaging showing reduced chiasmal size. RESULTS Three of the children had an associated skull base encephalocele with agenesis of the corpus callosum. In two patients achiasmia was associated with septo-optic dysplasia. Three patients had no neuroimaging abnormalities other than reduced chiasmal size and have no known pituitary dysfunction. One child had multiple physical deformities but the only brain imaging abnormality was reduced chiasmal size. CONCLUSIONS Some children with disorders of midline central nervous system development, including septo-optic dysplasia and skull base encephaloceles, have congenitally reduced chiasmal decussation. Reduced relative decussation may co-exist with overall chiasmal hypoplasia. Children with an apparently isolated chiasmal decussation deficit may have other subtle neurological findings, but our clinical impression is that most of these children function well.
Collapse
Affiliation(s)
- D A Sami
- Visual Sciences Unit, Institute of Child Health University College, London WC1N 1EH, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|