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Borchert GA, Shamsnajafabadi H, Ng BWJ, Xue K, De Silva SR, Downes SM, MacLaren RE, Cehajic-Kapetanovic J. Age-related macular degeneration: suitability of optogenetic therapy for geographic atrophy. Front Neurosci 2024; 18:1415575. [PMID: 39010943 PMCID: PMC11246919 DOI: 10.3389/fnins.2024.1415575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 06/18/2024] [Indexed: 07/17/2024] Open
Abstract
Age-related macular degeneration (AMD) is a growing public health concern given the aging population and it is the leading cause of blindness in developed countries, affecting individuals over the age of 55 years. AMD affects the retinal pigment epithelium (RPE) and Bruch's membrane in the macula, leading to secondary photoreceptor degeneration and eventual loss of central vision. Late AMD is divided into two forms: neovascular AMD and geographic atrophy (GA). GA accounts for around 60% of late AMD and has been the most challenging subtype to treat. Recent advances include approval of new intravitreally administered therapeutics, pegcetacoplan (Syfovre) and avacincaptad pegol (Iveric Bio), which target complement factors C3 and C5, respectively, which slow down the rate of enlargement of the area of atrophy. However, there is currently no treatment to reverse the central vision loss associated with GA. Optogenetics may provide a strategy for rescuing visual function in GA by imparting light-sensitivity to the surviving inner retina (i.e., retinal ganglion cells or bipolar cells). It takes advantage of residual inner retinal architecture to transmit visual stimuli along the visual pathway, while a wide range of photosensitive proteins are available for consideration. Herein, we review the anatomical changes in GA, discuss the suitability of optogenetic therapeutic sensors in different target cells in pre-clinical models, and consider the advantages and disadvantages of different routes of administration of therapeutic vectors.
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Affiliation(s)
- Grace A. Borchert
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Hoda Shamsnajafabadi
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Benjamin W. J. Ng
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Samantha R. De Silva
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Susan M. Downes
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
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2
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Xiao J, Zhang JY, Luo W, He PC, Skondra D. The Emerging Role of Gut Microbiota in Age-Related Macular Degeneration. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1627-1637. [PMID: 37156326 DOI: 10.1016/j.ajpath.2023.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/14/2023] [Accepted: 04/11/2023] [Indexed: 05/10/2023]
Abstract
Age-related macular degeneration (AMD) is a progressive, degenerative retinal disease that is a leading cause of blindness globally. Although multiple risk factors have been identified regarding disease incidence and progression, including smoking, genetics, and diet, the understanding of AMD pathogenesis remains unclear. As such, primary prevention is lacking, and current treatments have limited efficacy. More recently, the gut microbiome has emerged as an influential player in various ocular pathologies. As mediators of metabolism and immune regulation, perturbations in gut microbiota may impart significant effects distally on the neuroretina and its adjacent tissues, termed the gut-retina axis. In this review, key studies over the past several decades are summarized, both in humans and in animal models, which shed insight on the relationships between the gut microbiome and retinal biology and their implications for AMD. The literature linking gut dysbiosis with AMD is examined, along with preclinical animal models and techniques apt for studying the role of gut microbiota in AMD pathogenesis, which include interactions with systemic inflammation, immune regulation, chorioretinal gene expression, and diet. As understanding of the gut-retina axis continues to advance, so too will the possibility for more accessible and effective prevention and therapy of this vision-threatening condition.
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Affiliation(s)
- Jason Xiao
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois
| | - Jason Y Zhang
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois
| | - Wendy Luo
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois
| | - P Cody He
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois
| | - Dimitra Skondra
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois.
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3
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Gibson BG, Cox TE, Marchbank KJ. Contribution of animal models to the mechanistic understanding of Alternative Pathway and Amplification Loop (AP/AL)-driven Complement-mediated Diseases. Immunol Rev 2023; 313:194-216. [PMID: 36203396 PMCID: PMC10092198 DOI: 10.1111/imr.13141] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This review aimed to capture the key findings that animal models have provided around the role of the alternative pathway and amplification loop (AP/AL) in disease. Animal models, particularly mouse models, have been incredibly useful to define the role of complement and the alternative pathway in health and disease; for instance, the use of cobra venom factor and depletion of C3 provided the initial insight that complement was essential to generate an appropriate adaptive immune response. The development of knockout mice have further underlined the importance of the AP/AL in disease, with the FH knockout mouse paving the way for the first anti-complement drugs. The impact from the development of FB, properdin, and C3 knockout mice closely follows this in terms of mechanistic understanding in disease. Indeed, our current understanding that complement plays a role in most conditions at one level or another is rooted in many of these in vivo studies. That C3, in particular, has roles beyond the obvious in innate and adaptive immunity, normal physiology, and cellular functions, with or without other recognized AP components, we would argue, only extends the reach of this arm of the complement system. Humanized mouse models also continue to play their part. Here, we argue that the animal models developed over the last few decades have truly helped define the role of the AP/AL in disease.
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Affiliation(s)
- Beth G. Gibson
- Complement Therapeutics Research Group and Newcastle University Translational and Clinical Research InstituteFaculty of Medical ScienceNewcastle‐upon‐TyneUK
- National Renal Complement Therapeutics CentreaHUS ServiceNewcastle upon TyneUK
| | - Thomas E. Cox
- Complement Therapeutics Research Group and Newcastle University Translational and Clinical Research InstituteFaculty of Medical ScienceNewcastle‐upon‐TyneUK
- National Renal Complement Therapeutics CentreaHUS ServiceNewcastle upon TyneUK
| | - Kevin J. Marchbank
- Complement Therapeutics Research Group and Newcastle University Translational and Clinical Research InstituteFaculty of Medical ScienceNewcastle‐upon‐TyneUK
- National Renal Complement Therapeutics CentreaHUS ServiceNewcastle upon TyneUK
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4
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Zhao TT, Wen-Fei W, Kun G, Si-Ming L, Ye J, Yang ZF, Jian-Nan L, Yan-Li W, Shao-Min P. Fibroblast growth factor-21 alleviates phenotypic characteristics of dry age-related macular degeneration in mice. Exp Eye Res 2022; 218:109014. [PMID: 35245515 DOI: 10.1016/j.exer.2022.109014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 02/13/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
Abstract
Age-related macular degeneration (AMD) is the main cause of blindness in elderly individuals. As a metabolic regulator, fibroblast growth factor 21 (FGF-21) has been proven indicated to have an effect on wet AMD, but whether this cytokine has a therapeutic effect on dry AMD is unclear. The current study aimed to evaluate the preventive effects of FGF-21 against retinal degeneration in mice and provide mechanistic insights. FGF-21-/- mice were raised to 10 months of age. Then, the morphological changes in the retinal pigment epithelium (RPE)/choroid of the mice were observed by transmission electron microscopy (TEM), and iTRAQ was used to detect the variations in the protein profile. Next, FGF-21-/- and wild-type mice of the same age were fed hydroquinone to generate a dry AMD mouse model to examine whether exogenous FGF-21 can interfere with the occurrence and development of dry AMD. In vivo studies revealed that following FGF-21 knockout, there was an increase in the expression of complement in the RPE/choroid concomitant with the occurrence of dry AMD-like pathological changes. Furthermore, exogenous FGF-21 administration effectively reversed this phenomenon. FGF-21 also demonstrated strong anti-inflammatory effects in the RPE/choroid by inhibiting the NF-κB pathway. In conclusion, the present study demonstrates that FGF-21 treatment presents a novel therapeutic approach for the prevention and development of dry AMD by reducing complement.
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Affiliation(s)
- Ting-Ting Zhao
- Aier School of Ophthalmology, Central South University, Changsha, 410015, China; Harbin Aier Eye Hospital, Harbin, 150016, China.
| | - Wang Wen-Fei
- School of Life Science, Northeast Agricultural University, Harbin, 150030, China.
| | - Gao Kun
- School of Life Science, Northeast Agricultural University, Harbin, 150030, China.
| | - Li Si-Ming
- Harbin University of Commerce, Harbin, 150076, China.
| | - Jiang Ye
- School of Life Science, Northeast Agricultural University, Harbin, 150030, China.
| | - Zhi-Feng Yang
- School of Life Science, Northeast Agricultural University, Harbin, 150030, China.
| | - Liu Jian-Nan
- Aier School of Ophthalmology, Central South University, Changsha, 410015, China; Harbin Aier Eye Hospital, Harbin, 150016, China.
| | - Wang Yan-Li
- School of Life Science, Northeast Agricultural University, Harbin, 150030, China.
| | - Peng Shao-Min
- Aier School of Ophthalmology, Central South University, Changsha, 410015, China; Harbin Aier Eye Hospital, Harbin, 150016, China; Aier Retina Institute, Changsha, 410015, China.
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5
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Feng L, Nie K, Huang Q, Fan W. Complement factor H deficiency combined with smoking promotes retinal degeneration in a novel mouse model. Exp Biol Med (Maywood) 2021; 247:77-86. [PMID: 34775843 DOI: 10.1177/15353702211052245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Age-related macular degeneration is the leading cause of blindness in the elderly. The Y402H polymorphism in complement factor H promotes disease-like pathogenesis, and a Cfh+/- murine model can replicate this phenotype, but only after two years. We reasoned that by combining CFH deficiency with cigarette smoke exposure, we might be able to accelerate disease progression to facilitate preclinical research in this disease. Wild-type and Cfh+/- mice were exposed to nose-only cigarette smoke for three months. Retinal tissue morphology and visual function were evaluated by optical coherence tomography, fundus photography and autofluorescence, and electroretinogram. Retinal pigment epithelial cell phenotype and ultrastructure were evaluated by immunofluorescence staining and transmission electron microscopy. Cfh+/- smoking mice showed a dome-like protruding lesion at the ellipsoid zone (drusen-like deposition), many retinal hyper-autofluorescence spots, and a marked decrease in A- and B-wave amplitudes. Compared with non-smoking mice, wild-type and Cfh+/- smoking mice showed sub-retinal pigment epithelium complement protein 3 deposition, activation of microglia, metabolic waste accumulation, and impairment of tight junctions. Microglia cells migrated into the photoreceptor outer segment layer in Cfh+/- smoking mice showed increased activation. Our results suggest that exposing Cfh+/- mice to smoking leads to earlier onset of age-related macular degeneration than in other animal models, which may facilitate preclinical research into the pathophysiology and treatment of this disease.
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Affiliation(s)
- Liwen Feng
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu 610041, China.,Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Kailai Nie
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu 610041, China.,Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qing Huang
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Wei Fan
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu 610041, China
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Bird A. Role of retinal pigment epithelium in age-related macular disease: a systematic review. Br J Ophthalmol 2020; 105:1469-1474. [PMID: 32950958 DOI: 10.1136/bjophthalmol-2020-317447] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/27/2020] [Accepted: 09/04/2020] [Indexed: 02/07/2023]
Abstract
Age-related macular disease (AMD) is a major cause of blindness and there is little treatment currently available by which the progress of the basic disorder can be modulated. Histological and clinical studies show that the major tissues involved are the outer retina, retinal pigment epithelium, Bruch's membrane and choroid. Because of a wide variation of phenotype from one case to another, it has been suggested that accurate phenotyping would be necessary for assessment of the effectiveness of treatment that is tissue-directed. However, based on findings from the study of human donor material and animal models of disease and of cell culture, it is concluded that retinal pigment epithelial dysfunction plays a central role in the disease process in most, if not all, cases of early AMD. The metabolism of phagosomal material, particularly lipids, and energy generation are interdependent, and dysfunction of both appears to be important in the genesis of disease. Evidence exists to suggest that both can be modulated therapeutically. These metabolic functions are amenable to further investigation in both the normal state and in disease. Once fully characterised, it is likely that treatment could be directed towards a limited number of functions in single tissue, thus simplifying treatment strategies.
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Affiliation(s)
- Alan Bird
- Genetics, Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Jeffery G, Sivaprasad S. A hidden footprint: embryological origins of age related macular degeneration. Eye (Lond) 2019; 33:1675-1676. [PMID: 30996337 DOI: 10.1038/s41433-019-0444-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 02/22/2019] [Indexed: 11/09/2022] Open
Affiliation(s)
- Glen Jeffery
- Institute of Ophthalmology, University College London, London, UK.
| | - Sobha Sivaprasad
- Institute of Ophthalmology, University College London, London, UK
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8
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Complement factor H regulates retinal development and its absence may establish a footprint for age related macular degeneration. Sci Rep 2019; 9:1082. [PMID: 30705315 PMCID: PMC6355813 DOI: 10.1038/s41598-018-37673-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/29/2018] [Indexed: 01/22/2023] Open
Abstract
Age related macular degeneration (AMD) is the most common blinding disease in those over 60 years. In 50% of cases it is associated with polymorphisms of complement factor H (FH), implicating immune vulnerability. But such individuals may exhibit abnormal outer retinal blood flow decades before disease initiation, suggesting an early disease footprint. FH is expressed in the retinal pigmented epithelium (RPE). During development the RPE is adjacent to the site of retinal mitosis and complex regulatory interactions occur between the relatively mature RPE and retinal neuronal precursors that control the cell cycle. Here we ask if the absence of FH from the RPE influences retinal development using a mouse CFH knockout (Cfh−/−) with an aged retinal degenerative phenotype. We reveal that from birth, these mice have significantly disrupted and delayed retinal development. However, once development is complete, their retinae appear relatively normal, although many photoreceptor and RPE mitochondria are abnormally large, suggesting dysfunction consistent with premature ATP decline in Cfh−/−. Total retinal mtDNA is also reduced and these deficits are associated shortly after with reduced retinal function. Cfh−/+ mice also show significant abnormal patterns of cell production but not as great as in Cfh−/−. These results reveal that not only is FH an important player in sculpting retinal development but also that the developmental abnormality in Cfh−/− likely establishes critical vulnerability for later aged retinal degeneration.
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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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10
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Complement factor H in AMD: Bridging genetic associations and pathobiology. Prog Retin Eye Res 2017; 62:38-57. [PMID: 28928087 DOI: 10.1016/j.preteyeres.2017.09.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 09/08/2017] [Accepted: 09/13/2017] [Indexed: 01/28/2023]
Abstract
Age-Related Macular Degeneration (AMD) is a complex multifactorial disease characterized in its early stages by lipoprotein accumulations in Bruch's Membrane (BrM), seen on fundoscopic exam as drusen, and in its late forms by neovascularization ("wet") or geographic atrophy of the Retinal Pigmented Epithelial (RPE) cell layer ("dry"). Genetic studies have strongly supported a relationship between the alternative complement cascade, in particular the common H402 variant in Complement Factor H (CFH) and development of AMD. However, the functional significance of the CFH Y402H polymorphism remains elusive. In this article, we critically review the literature surrounding the functional significance of this polymorphism. Furthermore, based on our group's studies we propose a model in which CFH H402 affects CFH binding to heparan sulfate proteoglycans leading to accelerated lipoprotein accumulation in BrM and drusen progression. We also review the literature on the role of other complement components in AMD pathobiologies, including C3a, C5a and the membrane attack complex (MAC), and on transgenic mouse models developed to interrogate in vivo the effects of the CFH Y402H polymorphism.
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