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Wang M, Su S, Jiang S, Sun X, Wang J. Role of amyloid β-peptide in the pathogenesis of age-related macular degeneration. BMJ Open Ophthalmol 2021; 6:e000774. [PMID: 34263061 PMCID: PMC8245440 DOI: 10.1136/bmjophth-2021-000774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/18/2021] [Indexed: 01/13/2023] Open
Abstract
Age-related macular degeneration (AMD) is the most common eye disease in elderly patients, which could lead to irreversible vision loss and blindness. Increasing evidence indicates that amyloid β-peptide (Aβ) might be associated with the pathogenesis of AMD. In this review, we would like to summarise the current findings in this field. The literature search was done from 1995 to Feb, 2021 with following keywords, ‘Amyloid β-peptide and age-related macular degeneration’, ‘Inflammation and age-related macular degeneration’, ‘Angiogenesis and age-related macular degeneration’, ‘Actin cytoskeleton and amyloid β-peptide’, ‘Mitochondrial dysfunction and amyloid β-peptide’, ‘Ribosomal dysregulation and amyloid β-peptide’ using search engines Pubmed, Google Scholar and Web of Science. Aβ congregates in subretinal drusen of patients with AMD and participates in the pathogenesis of AMD through enhancing inflammatory activity, inducing mitochondrial dysfunction, altering ribosomal function, regulating the lysosomal pathway, affecting RNA splicing, modulating angiogenesis and modifying cell structure in AMD. The methods targeting Aβ are shown to inhibit inflammatory signalling pathway and restore the function of retinal pigment epithelium cells and photoreceptor cells in the subretinal region. Targeting Aβ may provide a novel therapeutic strategy for AMD.
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Affiliation(s)
- Minwei Wang
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Shiqi Su
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, California, USA
| | - Shaoyun Jiang
- Stomatological Center, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Xinghuai Sun
- Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
| | - Jiantao Wang
- Shenzhen Eye Hospital, Shenzhen, Guangdong, China
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2
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Wang L, Mao X. Role of Retinal Amyloid-β in Neurodegenerative Diseases: Overlapping Mechanisms and Emerging Clinical Applications. Int J Mol Sci 2021; 22:2360. [PMID: 33653000 PMCID: PMC7956232 DOI: 10.3390/ijms22052360] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 02/03/2023] Open
Abstract
Amyloid-β (Aβ) accumulations have been identified in the retina for neurodegeneration-associated disorders like Alzheimer's disease (AD), glaucoma, and age-related macular degeneration (AMD). Elevated retinal Aβ levels were associated with progressive retinal neurodegeneration, elevated cerebral Aβ accumulation, and increased disease severity with a decline in cognition and vision. Retinal Aβ accumulation and its pathological effects were demonstrated to occur prior to irreversible neurodegeneration, which highlights its potential in early disease detection and intervention. Using the retina as a model of the brain, recent studies have focused on characterizing retinal Aβ to determine its applicability for population-based screening of AD, which warrants a further understanding of how Aβ manifests between these disorders. While current treatments directly targeting Aβ accumulations have had limited results, continued exploration of Aβ-associated pathological pathways may yield new therapeutic targets for preserving cognition and vision. Here, we provide a review on the role of retinal Aβ manifestations in these distinct neurodegeneration-associated disorders. We also discuss the recent applications of retinal Aβ for AD screening and current clinical trial outcomes for Aβ-associated treatment approaches. Lastly, we explore potential future therapeutic targets based on overlapping mechanisms of pathophysiology in AD, glaucoma, and AMD.
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Affiliation(s)
- Liang Wang
- Miller School of Medicine, University of Miami, Miami, FL 33136, USA;
| | - Xiaobo Mao
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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3
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Lynn SA, Johnston DA, Scott JA, Munday R, Desai RS, Keeling E, Weaterton R, Simpson A, Davis D, Freeman T, Chatelet DS, Page A, Cree AJ, Lee H, Newman TA, Lotery AJ, Ratnayaka JA. Oligomeric Aβ 1-42 Induces an AMD-Like Phenotype and Accumulates in Lysosomes to Impair RPE Function. Cells 2021; 10:413. [PMID: 33671133 PMCID: PMC7922851 DOI: 10.3390/cells10020413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 02/04/2021] [Accepted: 02/11/2021] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease-associated amyloid beta (Aβ) proteins accumulate in the outer retina with increasing age and in eyes of age-related macular degeneration (AMD) patients. To study Aβ-induced retinopathy, wild-type mice were injected with nanomolar human oligomeric Aβ1-42, which recapitulate the Aβ burden reported in human donor eyes. In vitro studies investigated the cellular effects of Aβ in endothelial and retinal pigment epithelial (RPE) cells. Results show subretinal Aβ-induced focal AMD-like pathology within 2 weeks. Aβ exposure caused endothelial cell migration, and morphological and barrier alterations to the RPE. Aβ co-localized to late-endocytic compartments of RPE cells, which persisted despite attempts to clear it through upregulation of lysosomal cathepsin B, revealing a novel mechanism of lysosomal impairment in retinal degeneration. The rapid upregulation of cathepsin B was out of step with the prolonged accumulation of Aβ within lysosomes, and contrasted with enzymatic responses to internalized photoreceptor outer segments (POS). Furthermore, RPE cells exposed to Aβ were identified as deficient in cargo-carrying lysosomes at time points that are critical to POS degradation. These findings imply that Aβ accumulation within late-endocytic compartments, as well as lysosomal deficiency, impairs RPE function over time, contributing to visual defects seen in aging and AMD eyes.
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Affiliation(s)
- Savannah A. Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - David A. Johnston
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton SO16 6YD, UK; (D.A.J.); (D.S.C.); (A.P.)
| | - Jenny A. Scott
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Rosie Munday
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Roshni S. Desai
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Ruaridh Weaterton
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Alexander Simpson
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Dillon Davis
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Thomas Freeman
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - David S. Chatelet
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton SO16 6YD, UK; (D.A.J.); (D.S.C.); (A.P.)
| | - Anton Page
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton SO16 6YD, UK; (D.A.J.); (D.S.C.); (A.P.)
| | - Angela J. Cree
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Helena Lee
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Tracey A. Newman
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Andrew J. Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - J. Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
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4
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Kaynezhad P, Tachtsidis I, Aboelnour A, Sivaprasad S, Jeffery G. Watching synchronous mitochondrial respiration in the retina and its instability in a mouse model of macular degeneration. Sci Rep 2021; 11:3274. [PMID: 33558624 PMCID: PMC7870852 DOI: 10.1038/s41598-021-82811-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/12/2021] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial function declines with age and in some diseases, but we have been unable to analyze this in vivo. Here, we optically examine retinal mitochondrial function as well as choroidal oxygenation and hemodynamics in aging C57 and complement factor H (CFH-/-) mice, proposed models of macular degeneration which suffer early retinal mitochondrial decline. In young C57s mitochondrial populations respire in coupled oscillatory behavior in cycles of ~ 8 min, which is phase linked to choroidal oscillatory hemodynamics. In aging C57s, the oscillations are less regular being ~ 14 min and more dissociated from choroidal hemodynamics. The mitochondrial oscillatory cycles are extended in CFH-/- mice being ~ 16 min and are further dissociated from choroidal hemodynamics. Mitochondrial decline occurs before age-related changes to choroidal vasculature, hence, is the likely origin of oscillatory disruption in hemodynamics. This technology offers a non-invasive technique to detect early retinal disease and its relationship to blood oxygenation in vivo and in real time.
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Affiliation(s)
- Pardis Kaynezhad
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Asmaa Aboelnour
- Histology and Cytology Department, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Sobha Sivaprasad
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.
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5
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Chibhabha F, Yaqi Y, Li F. Retinal involvement in Alzheimer's disease (AD): evidence and current progress on the non-invasive diagnosis and monitoring of AD-related pathology using the eye. Rev Neurosci 2020; 31:/j/revneuro.ahead-of-print/revneuro-2019-0119/revneuro-2019-0119.xml. [PMID: 32804680 DOI: 10.1515/revneuro-2019-0119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 06/04/2020] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is a common form of age-related dementia that mostly affects the aging population. Clinically, it is a disease characterized by impaired memory and progressive cognitive decline. Although the pathological hallmarks of AD have been traditionally described with a general confinement in the brain, recent studies have shown similar pathological changes in the retina, which is a developmental outgrowth of the forebrain. These AD-related neurodegenerative changes in the retina have been implicated to cause early visual problems in AD even before cognitive impairment becomes apparent. With recent advances in research, the commonly held view that AD-related cerebral pathology causes visual dysfunction through disruption of central visual pathways has been re-examined. Currently, several studies have already explored how AD manifests in the retina and the possibility of using the same retina as a window to non-invasively examine AD-related pathology in the brain. Non-invasive screening of AD through the retina has the potential to improve on early detection and management of the disease since the majority of AD cases are usually diagnosed very late. The purpose of this review is to provide evidence on the involvement of the retina in AD and to suggest a possible direction for future research into the non-invasive screening, diagnosis, and monitoring of AD using the retina.
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Affiliation(s)
- Fidelis Chibhabha
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou510080,China
- Department of Anatomy, Faculty of Medicine, Midlands State University, P. Bag 9055, Senga, Gweru, Zimbabwe
- and Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080,China
| | - Yang Yaqi
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou510080,China
- and Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080,China
| | - Feng Li
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou510080,China
- and Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080,China
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6
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Intracellular amyloid-β disrupts tight junctions of the retinal pigment epithelium via NF-κB activation. Neurobiol Aging 2020; 95:115-122. [PMID: 32795848 DOI: 10.1016/j.neurobiolaging.2020.07.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 07/07/2020] [Accepted: 07/14/2020] [Indexed: 12/16/2022]
Abstract
Drusen are focal deposits between the retinal pigment epithelium (RPE) and Bruch's membrane in the retina of patients with age-related macular degeneration. Amyloid-β is one of the important components of drusen, which leads to local inflammation. Furthermore, intracellular amyloid-β disrupts tight junctions of the RPE. However, the intracellular mechanisms linking intracellular amyloid-β and tight-junction disruption are not clear. In this study, intracellular amyloid-β oligomers activated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65, leading to the disorganization of tight junctions of the RPE in mice after subretinal injection of amyloid-β. Amyloid-β also triggered NF-κB activation in the RPE cells in confluent culture, which was inhibited by the suppression of the advanced glycosylation end product-specific receptor. NF-κB inhibition by an IκB kinase inhibitor prevented the suppression of expression of tight-junction proteins, zonula occuludens-1 and occludin in RPE cells. In addition, tight-junction complexes remained intact in the RPE of mice with NF-κB inhibition, although there were intracellular amyloid-β oligomers. These data suggested that NF-κB inhibition might be a therapeutic approach to prevent amyloid-β-mediated tight-junction disruption.
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7
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Kam JH, Weinrich TW, Shinhmar H, Powner MB, Roberts NW, Aboelnour A, Jeffery G. Fundamental differences in patterns of retinal ageing between primates and mice. Sci Rep 2019; 9:12574. [PMID: 31467395 PMCID: PMC6715671 DOI: 10.1038/s41598-019-49121-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/06/2019] [Indexed: 01/09/2023] Open
Abstract
Photoreceptors have high metabolic demands and age rapidly, undermining visual function. We base our understanding mainly on ageing mice where elevated inflammation, extracellular deposition, including that of amyloid beta, and rod and cone photoreceptor loss occur, but cones are not lost in ageing primate although their function declines, revealing that primate and mouse age differently. We examine ageing primate retinae and show elevated stress but low inflammation. However, aged primates have a >70% reduction in adenosine triphosphate (ATP) and a decrease in cytochrome c oxidase. There is a shift in cone mitochondrial positioning and glycolytic activity increases. Bruch’s membrane thickens but unlike in mice, amyloid beta is absent. Hence, reduced ATP may explain cone functional decline in ageing but their retained presence offers the possibility of functional restoration if they can be fuelled appropriately to restore cellular function. This is important because as humans we largely depend on cone function to see and are rarely fully dark adapted. Presence of limited aged inflammation and amyloid beta deposition question some of the therapeutic approaches taken to resolve problems of retinal ageing in humans and the possible lack of success in clinical trials in macular degeneration that have targeted inflammatory agents.
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Affiliation(s)
- Jaimie Hoh Kam
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK
| | - Tobias W Weinrich
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK
| | - Harpreet Shinhmar
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK
| | - Michael B Powner
- City, University of London, Centre of Applied Vision Research, EC1V0HB, London, UK
| | - Nicholas W Roberts
- School of Biological Sciences, University of Bristol, BS8 1TQ, Bristol, UK
| | - Asmaa Aboelnour
- Histology and Cytology Department, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Glen Jeffery
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK.
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8
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Ibbett P, Goverdhan SV, Pipi E, Chouhan JK, Keeling E, Angus EM, Scott JA, Gatherer M, Page A, Teeling JL, Lotery AJ, Arjuna Ratnayaka J. A lasered mouse model of retinal degeneration displays progressive outer retinal pathology providing insights into early geographic atrophy. Sci Rep 2019; 9:7475. [PMID: 31097765 PMCID: PMC6522499 DOI: 10.1038/s41598-019-43906-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/03/2019] [Indexed: 12/14/2022] Open
Abstract
Early stages of geographic atrophy (GA) age-related macular degeneration is characterised by the demise of photoreceptors, which precedes the loss of underlying retinal pigment epithelial (RPE) cells. Sight-loss due to GA has no effective treatment; reflecting both the complexity of the disease and the lack of suitable animal models for testing potential therapies. We report the development and characterisation of a laser-induced mouse model with early GA-like pathology. Retinas were lasered at adjacent sites using a 810 nm laser (1.9 J/spot), resulting in the development of confluent, hypopigmented central lesions with well-defined borders. Optical Coherence Tomography over 2-months showed progressive obliteration of photoreceptors with hyper-reflective outer plexiform and RPE/Bruch’s membrane (BrM) layers within lesions, but an unaffected inner retina. Light/electron microscopy after 3-months revealed lesions without photoreceptors, leaving the outer plexiform layer apposed to the RPE. We observed outer segment debris, hypo/hyperpigmented RPE, abnormal apical-basal RPE surfaces and BrM thickening. Lesions had wedge-shaped margins, extended zones of damage, activated Müller cells, microglial recruitment and functional retinal deficits. mRNA studies showed complement and inflammasome activation, microglial/macrophage phagocytosis and oxidative stress providing mechanistic insights into GA. We propose this mouse model as an attractive tool for early GA studies and drug-discovery.
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Affiliation(s)
- Paul Ibbett
- Biological Sciences, University of Southampton, SGH, South Lab and Path Block, MP840, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Srinivas V Goverdhan
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom.,Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, SO16 6YD, United Kingdom
| | - Elena Pipi
- Biological Sciences, University of Southampton, SGH, South Lab and Path Block, MP840, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Joe K Chouhan
- Biological Sciences, University of Southampton, SGH, South Lab and Path Block, MP840, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Elizabeth M Angus
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Jenny A Scott
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Maureen Gatherer
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Anton Page
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Jessica L Teeling
- Biological Sciences, University of Southampton, SGH, South Lab and Path Block, MP840, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom. .,Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, SO16 6YD, United Kingdom.
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom.
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9
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Rosenfeld PJ, Berger B, Reichel E, Danis RP, Gress A, Ye L, Magee M, Parham LR, McLaughlin MM. A Randomized Phase 2 Study of an Anti–Amyloid β Monoclonal Antibody in Geographic Atrophy Secondary to Age-Related Macular Degeneration. ACTA ACUST UNITED AC 2018; 2:1028-1040. [DOI: 10.1016/j.oret.2018.03.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/16/2018] [Accepted: 03/01/2018] [Indexed: 11/28/2022]
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10
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Lashkari K, Teague G, Chen H, Lin YQ, Kumar S, McLaughlin MM, López FJ. A monoclonal antibody targeting amyloid β (Aβ) restores complement factor I bioactivity: Potential implications in age-related macular degeneration and Alzheimer's disease. PLoS One 2018; 13:e0195751. [PMID: 29782502 PMCID: PMC5962057 DOI: 10.1371/journal.pone.0195751] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/28/2018] [Indexed: 11/18/2022] Open
Abstract
Activation of the alternative complement cascade has been implicated in the pathogenesis of age related macular degeneration (AMD) and Alzheimer’s disease (AD). Amyloid β (Aβ), a component of drusen, may promote complement activation by inhibiting CFI bioactivity. We determined whether Aβ reduced CFI bioactivity and whether antibodies against Aβ including a monoclonal antibody, GSK933776 could restore CFI bioactivity. We also measured CFI bioactivity in plasma of subjects with AMD and AD. In support of the GSK933776 development program in AMD (geographic atrophy), we developed a quantitative assay to measure CFI bioactivity based on its ability to cleave C3b to iC3b, and repeated it in presence or absence of Aβ and anti-Aβ antibodies. Using this assay, we measured CFI bioactivity in plasma of 194 subjects with AMD, and in samples from subjects with AD that had been treated with GSK933776 as part of the GSK933776 development program in AD. Aβ reduced the CFI bioactivity by 5-fold and pre-incubation with GSK933776 restored CFI bioactivity. In subjects with AMD, plasma CFI levels and bioactivity were not significantly different from non-AMD controls. However, we detected a positive linear trend, suggesting increasing activity with disease severity. In subjects with AD, we observed a 10% and 27% increase in overall CFI bioactivity after treatment with GSK933776 during the second and third dose. Our studies indicate that CFI enzymatic activity can be inhibited by Aβ and be altered in proinflammatory diseases such as AMD and AD, in which deposition of Aβ and activation of the alternative complement cascade are believed to play a key role in the disease process.
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Affiliation(s)
- Kameran Lashkari
- Schepens Eye Research Institute, Mass Eye & Ear, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Gianna Teague
- Schepens Eye Research Institute, Mass Eye & Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hong Chen
- Alliance Pharma, Malvern, Pennsylvania, United States of America
| | - Yong-Qing Lin
- Alliance Pharma, Malvern, Pennsylvania, United States of America
| | - Sanjay Kumar
- Alternative Discovery & Development, GlaxoSmithKline, King of Prussia, Pennsylvania, United States of America
| | - Megan M. McLaughlin
- Alternative Discovery & Development, GlaxoSmithKline, King of Prussia, Pennsylvania, United States of America
| | - Francisco J. López
- Alternative Discovery & Development, GlaxoSmithKline, King of Prussia, Pennsylvania, United States of America
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11
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Mullins RF, Warwick AN, Sohn EH, Lotery AJ. From compliment to insult: genetics of the complement system in physiology and disease in the human retina. Hum Mol Genet 2017; 26:R51-R57. [PMID: 28482029 DOI: 10.1093/hmg/ddx181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/05/2017] [Indexed: 01/11/2023] Open
Abstract
Age-related macular degeneration (AMD) is a major cause of visual impairment that affects the central retina. Genome wide association studies and candidate gene screens have identified members of the complement pathway as contributing to the risk of AMD. In this review, we discuss the complement system, its importance in retinal development and normal physiology, how its dysregulation may contribute to disease, and how it might be targeted to prevent damage to the aging choriocapillaris in AMD.
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Affiliation(s)
- Robert F Mullins
- Department of Ophthalmology and Visual Sciences.,Stephen A. Wynn Institute for Vision Research, University of Iowa, Iowa City, IA, USA
| | - Alasdair N Warwick
- Western Eye Hospital, Imperial College Healthcare NHS Foundation Trust, London, UK
| | - Elliott H Sohn
- Department of Ophthalmology and Visual Sciences.,Stephen A. Wynn Institute for Vision Research, University of Iowa, Iowa City, IA, USA
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
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12
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Biswal MR, Han P, Zhu P, Wang Z, Li H, Ildefonso CJ, Lewin AS. Timing of Antioxidant Gene Therapy: Implications for Treating Dry AMD. Invest Ophthalmol Vis Sci 2017; 58:1237-1245. [PMID: 28241311 PMCID: PMC5338629 DOI: 10.1167/iovs.16-21272] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose To investigate whether antioxidant gene therapy protects the structure and function of retina in a murine model of RPE atrophy, and to determine whether antioxidant gene therapy can prevent degeneration once it has begun. Methods We induced mitochondrial oxidative stress in RPE by conditional deletion of Sod2, the gene for manganese superoxide dismutase (MnSOD). These mice exhibited localized atrophy of the RPE and overlying photoreceptors. We restored Sod2 to the RPE of one eye using adeno-associated virus (AAV) by subretinal injection at an early (6 weeks) and a late stage (6 months), injecting the other eye with an AAV vector expressing green fluorescent protein (GFP). Retinal degeneration was monitored over a period of 9 months by electroretinography (ERG) and spectral-domain optical coherence tomography (SD-OCT). Immunohistochemical and histologic analyses were conducted to measure oxidative stress markers and to visualize retinal structure. Results One month after delivery, the AAV-Sod2 injection resulted in production of MnSod in the RPE and negligible expression in the neural retina. Electroretinography and OCT suggested no adverse effects due to increased expression of MnSOD or subretinal injection. Decrease in the ERG response and thinning retinal thickness was significantly delayed in eyes with early treatment with the Sod2 vector, but treatment at 6 months of age did not affect the ERG decline seen in these mice. Conclusions We conclude that antioxidant gene therapy may be effective in preventing the detrimental effects of oxidative stress, but may not be beneficial once substantial tissue damage has occurred.
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Affiliation(s)
- Manas R Biswal
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Pingyang Han
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Ping Zhu
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Zhaoyang Wang
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Hong Li
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Cristhian J Ildefonso
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, United States
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, United States
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13
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Sivapathasuntharam C, Sivaprasad S, Hogg C, Jeffery G. Aging retinal function is improved by near infrared light (670 nm) that is associated with corrected mitochondrial decline. Neurobiol Aging 2017; 52:66-70. [PMID: 28129566 PMCID: PMC5364001 DOI: 10.1016/j.neurobiolaging.2017.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 01/01/2017] [Accepted: 01/02/2017] [Indexed: 11/01/2022]
Abstract
Aging is associated with cellular decline and reduced function, partly mediated by mitochondrial compromise. However, aged mitochondrial function is corrected with near infrared light (670 nm) that improves their membrane potentials and adenosine triphosphate production and also reduces age-related inflammation. We ask if 670 nm light can also improve declining retinal function. Electroretinograms were measured in 2-, 7-, and 12-month old C57BL/6 mice. Significant age-related declines were measured in the photoreceptor generated a-wave and the postreceptoral b-wave. Seven- and 12-month-old mice were exposed to 670 nm for 15 minutes daily over 1 month. These showed significant improved retinal function in both waves of approximately 25% but did not reach levels found in 2-month-old animals. Our data suggest, 670 nm light can significantly improve aged retinal function, perhaps by providing additional adenosine triphosphate production for photoreceptor ion pumps or reduced aged inflammation. This may have implications for the treatment of retinal aging and age-related retinal disease, such as macular degeneration.
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Affiliation(s)
| | | | | | - Glen Jeffery
- University College London Institute of Ophthalmology, London, UK.
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14
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Taylor-Walker G, Lynn SA, Keeling E, Munday R, Johnston DA, Page A, Scott JA, Goverdhan S, Lotery AJ, Ratnayaka JA. The Alzheimer's-related amyloid beta peptide is internalised by R28 neuroretinal cells and disrupts the microtubule associated protein 2 (MAP-2). Exp Eye Res 2016; 153:110-121. [PMID: 27751744 PMCID: PMC5131630 DOI: 10.1016/j.exer.2016.10.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/12/2016] [Accepted: 10/11/2016] [Indexed: 11/15/2022]
Abstract
Age-related Macular Degeneration (AMD) is a common, irreversible blinding condition that leads to the loss of central vision. AMD has a complex aetiology with both genetic as well as environmental risks factors, and share many similarities with Alzheimer's disease. Recent findings have contributed significantly to unravelling its genetic architecture that is yet to be matched by molecular insights. Studies are made more challenging by observations that aged and AMD retinas accumulate the highly pathogenic Alzheimer's-related Amyloid beta (Aβ) group of peptides, for which there appears to be no clear genetic basis. Analyses of human donor and animal eyes have identified retinal Aβ aggregates in retinal ganglion cells (RGC), the inner nuclear layer, photoreceptors as well as the retinal pigment epithelium. Aβ is also a major drusen constituent; found correlated with elevated drusen-load and age, with a propensity to aggregate in retinas of advanced AMD. Despite this evidence, how such a potent driver of neurodegeneration might impair the neuroretina remains incompletely understood, and studies into this important aspect of retinopathy remains limited. In order to address this we exploited R28 rat retinal cells which due to its heterogeneous nature, offers diverse neuroretinal cell-types in which to study the molecular pathology of Aβ. R28 cells are also unaffected by problems associated with the commonly used RGC-5 immortalised cell-line, thus providing a well-established model in which to study dynamic Aβ effects at single-cell resolution. Our findings show that R28 cells express key neuronal markers calbindin, protein kinase C and the microtubule associated protein-2 (MAP-2) by confocal immunofluorescence which has not been shown before, but also calretinin which has not been reported previously. For the first time, we reveal that retinal neurons rapidly internalised Aβ1-42, the most cytotoxic and aggregate-prone amongst the Aβ family. Furthermore, exposure to physiological amounts of Aβ1-42 for 24 h correlated with impairment to neuronal MAP-2, a cytoskeletal protein which regulates microtubule dynamics in axons and dendrites. Disruption to MAP-2 was transient, and had recovered by 48 h, although internalised Aβ persisted as discrete puncta for as long as 72 h. To assess whether Aβ could realistically localise to living retinas to mediate such effects, we subretinally injected nanomolar levels of oligomeric Aβ1-42 into wildtype mice. Confocal microscopy revealed the presence of focal Aβ deposits in RGC, the inner nuclear and the outer plexiform layers 8 days later, recapitulating naturally-occurring patterns of Aβ aggregation in aged retinas. Our novel findings describe how retinal neurons internalise Aβ to transiently impair MAP-2 in a hitherto unreported manner. MAP-2 dysfunction is reported in AMD retinas, and is thought to be involved in remodelling and plasticity of post-mitotic neurons. Our insights suggest a molecular pathway by which this could occur in the senescent eye leading to complex diseases such as AMD. Molecular basis of complex retinopathies such as AMD is incompletely understood. The Alzheimer's-related Aβ peptides are rapidly internalised by retinal neurons. Internalised Aβ is retained within neurons and transiently impairs MAP-2. Subretinally injected Aβ mimics its naturally-occurring distribution in aged retinas.
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Affiliation(s)
- George Taylor-Walker
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Savannah A Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Rosie Munday
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - David A Johnston
- Biomedical Imaging Unit, University of Southampton, SGH, MP12, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Anton Page
- Biomedical Imaging Unit, University of Southampton, SGH, MP12, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Jennifer A Scott
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Srini Goverdhan
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom; Eye Unit, University Southampton NHS Trust, Southampton, SO16 6YD, United Kingdom
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom.
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15
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Kaynezhad P, Tachtsidis I, Jeffery G. Optical monitoring of retinal respiration in real time: 670 nm light increases the redox state of mitochondria. Exp Eye Res 2016; 152:88-93. [PMID: 27664904 PMCID: PMC5105829 DOI: 10.1016/j.exer.2016.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/18/2016] [Accepted: 09/20/2016] [Indexed: 02/03/2023]
Abstract
Mitochondria play a key role in ageing and disease. Their membrane potentials and ATP production decline with age and this is associated with progressive inflammation, cell loss and death. Here we use broadband Near-Infrared Spectroscopy (NIRS) to non-invasively measure in-vivo changes in aged retinal mitochondrial respiration following exposure to 670 nm, which improves mitochondrial performance and reduces inflammation. Low power NIR light was shone into the eye via a fibre optic and the reflection monitored to measure signature changes in the oxidation of cytochrome c oxidase (COX) in complex IV of the electron transport chain. Changes in retinal haemodynamics and oxygenation were also recorded simultaneously with COX by measuring changes in oxygenated and deoxygenated haemoglobin (Δ[HbO2] and Δ[HHb]). Retinae of aged rats exposed to 670 nm for 5 mins showed consistent progressive increases in oxidation of COX 5 mins post exposure. This remained significantly greater than baseline for up to 2 h. This was not seen when retinae were exposed to 420 nm light of the same power or when no light was applied. 670 nm exposure significantly increased total haemoglobin concentration (Δ[HbT] = Δ[HbO2] +Δ[HHb]) but not haemoglobin difference (Δ[HbDiff] = Δ[HbO2] -Δ[HHb]). There were no changes in blood metrics in association with 420 nm light or when no light exposure was given. Hence, brief 670 nm exposure that is associated with reduced inflammation has a significant positive impact on the redox state of COX in aged retinae. The relative redox state of retinal COX may provide a valuable biomarker in ageing and macular degeneration where declining mitochondrial function is implicated. We measure real time retinal reflections in vivo in rats. We isolate signals from oxy/deoxy haemoglobin and those from relative COX redox. 670 nm increases COX redox and total haemoglobin improving mitochondrial function. These measurements monitor retinal respiration and may be a biomarker for disease.
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Affiliation(s)
- Pardis Kaynezhad
- Dept of Medical Physics and Biomedical Engineering, University College London, UK
| | - Ilias Tachtsidis
- Dept of Medical Physics and Biomedical Engineering, University College London, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, UK.
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16
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Perspectives on reticular pseudodrusen in age-related macular degeneration. Surv Ophthalmol 2016; 61:521-37. [DOI: 10.1016/j.survophthal.2016.02.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/22/2016] [Accepted: 02/26/2016] [Indexed: 11/20/2022]
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17
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Hoh Kam J, Morgan JE, Jeffery G. Aged complement factor H knockout mice kept in a clean barriered environment have reduced retinal pathology. Exp Eye Res 2016; 149:116-125. [PMID: 27397653 DOI: 10.1016/j.exer.2016.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 06/14/2016] [Accepted: 07/06/2016] [Indexed: 01/02/2023]
Abstract
Age-related macular degeneration (AMD) is the largest cause of visual loss in those over 60 years in the West and is a condition increasing in prevalence. Many diseases result from genetic/environmental interactions and 50% of AMD cases have an association with polymorphisms of the complement system including complement factor H. Here we explore interactions between genetic predisposition and environmental conditions in triggering retinal pathology in two groups of aged complement factor H knock out (Cfh(-/-)) mice. Mice were maintained over 9 months in either a conventional open environment or a barriered pathogen free environment. Open environment Cfh(-/-) mice had significant increases in subretinal macrophage numbers, inflammatory and stress responses and reduced photoreceptor numbers over mice kept in a pathogen free environment. Hence, environmental factors can drive retinal disease in these mice when linked to complement deficits impairing immune function. Both groups of mice had similar levels of retinal amyloid beta accumulation. Consequently there is no direct link between this and inflammation in Cfh(-/-) mice.
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Affiliation(s)
- Jaimie Hoh Kam
- Institute of Ophthalmology, University College London, UK
| | - James E Morgan
- School of Optometry and Visual Science, Cardiff University, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, UK.
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18
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Nanoceria: a Potential Therapeutic for Dry AMD. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:111-8. [DOI: 10.1007/978-3-319-17121-0_16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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19
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Abstract
Age-related macular degeneration (AMD), the most common form of irreversible blindness in the industrially developed world, can present years before a patient begins to lose vision. For most of these patients, AMD never progresses past its early stages to the advanced forms that are principally responsible for the vast majority of vision loss. Advanced AMD can manifest as either an advanced avascular form known as geographic atrophy (GA) marked by regional retinal pigment epithelium (RPE) cell death or as an advanced form known as neovascular AMD marked by the intrusion of fragile new blood vessels into the normally avascular retina. Physicians have several therapeutic interventions available to combat neovascular AMD, but GA has no approved effective therapies as of yet. In this chapter, we will discuss the current strategies for limiting dry AMD in patients. We will also discuss previous attempts at pharmacological intervention that were tested in a clinical setting and consider reasons why these putative therapeutics did not perform successfully in large-scale trials. Despite the number of unsuccessful past trials, new pharmacological interventions may succeed. These future therapies may aid millions of AMD patients worldwide.
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Affiliation(s)
- Charles B Wright
- Physiology and Ophthalmology and Visual Sciences, University of Kentucky College of Medicine, Lexington, KY, 40506, USA
| | - Jayakrishna Ambati
- Physiology and Ophthalmology and Visual Sciences, University of Kentucky College of Medicine, Lexington, KY, 40506, USA.
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20
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Calaza KC, Kam JH, Hogg C, Jeffery G. Mitochondrial decline precedes phenotype development in the complement factor H mouse model of retinal degeneration but can be corrected by near infrared light. Neurobiol Aging 2015; 36:2869-76. [PMID: 26149919 DOI: 10.1016/j.neurobiolaging.2015.06.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 06/02/2015] [Accepted: 06/05/2015] [Indexed: 11/18/2022]
Abstract
Mitochondria produce adenosine triphosphate (ATP), critical for cellular metabolism. ATP declines with age, which is associated with inflammation. Here, we measure retinal and brain ATP in normal C57BL/6 and complement factor H knockout mice (Cfh(-/-)), which are proposed as a model of age-related macular degeneration. We show a significant premature 30% decline in retinal ATP in Cfh(-/-) mice and a subsequent shift in expression of a heat shock protein that is predominantly mitochondrial (Hsp60). Changes in Hsp60 are associated with stress and neuroprotection. We find no differences in brain ATP between C57BL/6 and Cfh(-/-) mice. Near infrared (NIR) increases ATP and reduces inflammation. ATP decline in Cfh(-/-) mice was corrected with NIR which also shifted Hsp60 labeling patterns. ATP decline in Cfh(-/-) mice occurs before inflammation becomes established and photoreceptor loss occurs and may relate to disease etiology. However, ATP levels were corrected with NIR. In summary, we provide evidence for a mitochondrial basis for this disease in mice and correct this with simple light exposure known to improve mitochondrial function.
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Affiliation(s)
- Karin C Calaza
- Program of Neurosciences, Institute of Biology, Federal Fluminense University, Rio de Janeiro, Brazil; Institute of Ophthalmology University College London, London, UK
| | - Jaimie Hoh Kam
- Institute of Ophthalmology University College London, London, UK
| | | | - Glen Jeffery
- Institute of Ophthalmology University College London, London, UK.
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21
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Hoh Kam J, Lynch A, Begum R, Cunea A, Jeffery G. Topical cyclodextrin reduces amyloid beta and inflammation improving retinal function in ageing mice. Exp Eye Res 2015; 135:59-66. [PMID: 25921262 DOI: 10.1016/j.exer.2015.03.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/18/2015] [Accepted: 03/25/2015] [Indexed: 12/31/2022]
Abstract
Retinal ageing results in chronic inflammation, extracellular deposition, including that of amyloid beta (Aβ) and declining visual function. In humans this can progress into age-related macular degeneration (AMD), which is without cure. Therapeutic approaches have focused on systemic immunotherapies without clinical resolution. Here, we show using aged mice that 2-Hydroxypropyl-β-cyclodextrin, a sugar molecule given as eye drops over 3 months results in significant reductions in Aβ by 65% and inflammation by 75% in the aged mouse retina. It also elevates retinal pigment epithelium specific protein 65 (RPE65), a key molecule in the visual cycle, in aged retina. These changes are accompanied by a significant improvement in retinal function measured physiologically. 2-Hydroxypropyl-β-cyclodextrin is as effective in reducing Aβ and inflammation in the complement factor H knockout (Cfh(-/-)) mouse that shows advanced ageing and has been proposed as an AMD model. β-cyclodextrin is economic, safe and may provide an efficient route to reducing the impact of retinal ageing.
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Affiliation(s)
- Jaimie Hoh Kam
- Institute of Ophthalmology, University College London, UK
| | - Aisling Lynch
- Institute of Ophthalmology, University College London, UK
| | - Rana Begum
- Institute of Ophthalmology, University College London, UK
| | - Alex Cunea
- Institute of Ophthalmology, University College London, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, UK.
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22
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Buschini E, Fea AM, Lavia CA, Nassisi M, Pignata G, Zola M, Grignolo FM. Recent developments in the management of dry age-related macular degeneration. Clin Ophthalmol 2015; 9:563-74. [PMID: 25878491 PMCID: PMC4388086 DOI: 10.2147/opth.s59724] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Dry age-related macular degeneration (AMD), also called geographic atrophy, is characterized by the atrophy of outer retinal layers and retinal pigment epithelium (RPE) cells. Dry AMD accounts for 80% of all intermediate and advanced forms of the disease. Although vision loss is mainly due to the neovascular form (75%), dry AMD remains a challenge for ophthalmologists because of the lack of effective therapies. Actual management consists of lifestyle modification, vitamin supplements, and supportive measures in the advanced stages. The Age-Related Eye Disease Study demonstrated a statistically significant protective effect of dietary supplementation of antioxidants (vitamin C, vitamin E, beta-carotene, zinc, and copper) on dry AMD progression rate. It was also stated that the consumption of omega-3 polyunsaturated fatty acids, such as docosahexaenoic acid and eicosapentaenoic acid, has protective effects. Other antioxidants, vitamins, and minerals (such as crocetin, curcumin, and vitamins B9, B12, and B6) are under evaluation, but the results are still uncertain. New strategies aim to 1) reduce or block drusen formation, 2) reduce or eliminate inflammation, 3) lower the accumulation of toxic by-products from the visual cycle, 4) reduce or eliminate retinal oxidative stress, 5) improve choroidal perfusion, 6) replace/repair or regenerate lost RPE cells and photoreceptors with stem cell therapy, and 7) develop a target gene therapy.
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Affiliation(s)
- Elisa Buschini
- Ospedale Oftalmico, Ophthalmic Section, Department of Clinical Pathophysiology, University of Turin, Turin, Italy
| | - Antonio M Fea
- Ospedale Oftalmico, Ophthalmic Section, Department of Clinical Pathophysiology, University of Turin, Turin, Italy
| | - Carlo A Lavia
- Ospedale Oftalmico, Ophthalmic Section, Department of Clinical Pathophysiology, University of Turin, Turin, Italy
| | - Marco Nassisi
- Ospedale Oftalmico, Ophthalmic Section, Department of Clinical Pathophysiology, University of Turin, Turin, Italy
| | - Giulia Pignata
- Ospedale Oftalmico, Ophthalmic Section, Department of Clinical Pathophysiology, University of Turin, Turin, Italy
| | - Marta Zola
- Ospedale Oftalmico, Ophthalmic Section, Department of Clinical Pathophysiology, University of Turin, Turin, Italy
| | - Federico M Grignolo
- Ospedale Oftalmico, Ophthalmic Section, Department of Clinical Pathophysiology, University of Turin, Turin, Italy
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23
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Warwick A, Khandhadia S, Ennis S, Lotery A. Age-Related Macular Degeneration: A Disease of Systemic or Local Complement Dysregulation? J Clin Med 2014; 3:1234-57. [PMID: 26237601 PMCID: PMC4470180 DOI: 10.3390/jcm3041234] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/20/2014] [Accepted: 10/22/2014] [Indexed: 01/25/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in developed countries. The role of complement in the development of AMD is now well-established. While some studies show evidence of complement dysregulation within the eye, others have demonstrated elevated systemic complement activation in association with AMD. It is unclear which one is the primary driver of disease. This has important implications for designing novel complement-based AMD therapies. We present a summary of the current literature and suggest that intraocular rather than systemic modulation of complement may prove more effective.
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Affiliation(s)
- Alasdair Warwick
- Clinical Neurosciences Research Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
| | - Samir Khandhadia
- Eye Unit, University Southampton NHS Trust, Southampton SO16 6YD, UK.
| | - Sarah Ennis
- Genomic Informatics, Human Genetics & Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
| | - Andrew Lotery
- Clinical Neurosciences Research Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
- Eye Unit, University Southampton NHS Trust, Southampton SO16 6YD, UK.
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24
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Querques G, Rosenfeld PJ, Cavallero E, Borrelli E, Corvi F, Querques L, Bandello FM, Zarbin MA. Treatment of Dry Age-Related Macular Degeneration. Ophthalmic Res 2014; 52:107-15. [DOI: 10.1159/000363187] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 04/12/2014] [Indexed: 11/19/2022]
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25
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Nitoda E, Koutsilieris M, Brouzas D, Koutsandrea C, Philippou A, Ladas D, Moschos MM. Correlation of platelet activating factor and age-related macular degeneration. Expert Opin Ther Targets 2014; 18:987-97. [PMID: 25077601 DOI: 10.1517/14728222.2014.930439] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE To investigate the role of Platelet Activating Factor (PAF) in the pathogenesis and development of Age-Related Macular Degeneration (ARMD). RESEARCH DESIGN AND METHODS Fifty six patients with ARMD (24 patients with dry ARMD and 32 patients with wet ARMD) and 25 age-matched control participants underwent ophthalmological examination, including visual acuity measurement and evaluation of the retina. The participants were classified into three groups according to their retinal status, based on indirect fundoscopy, Optical Coherence Tomography and fluorescein angiography findings. In order to evaluate the concentrations of PAF in serum, blood samples were collected from all participants and were analyzed with ELISA technique. RESULTS The concentrations of PAF differed significantly according to macular lesions and were found to be lower in patients with ARMD than control participants. CONCLUSIONS PAF levels are decreased along with the severity of ARMD. Understanding the role of PAF in pathogenesis of ARMD could be the impetus for the development of new therapies field of treatment of ARMD or even other retinal diseases.
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Affiliation(s)
- Eirini Nitoda
- National and Kapodistrian University of Athens, 1st Department of Ophthalmology, Medical School , Athens , Greece +306944887319 ; +302104122319 ;
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