1
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Biber J, Jabri Y, Glänzer S, Dort A, Hoffelner P, Schmidt CQ, Bludau O, Pauly D, Grosche A. Gliosis-dependent expression of complement factor H truncated variants attenuates retinal neurodegeneration following ischemic injury. J Neuroinflammation 2024; 21:56. [PMID: 38388518 PMCID: PMC10885619 DOI: 10.1186/s12974-024-03045-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/14/2024] [Indexed: 02/24/2024] Open
Abstract
Inherited, age-related, and acute retinal diseases are often exacerbated by an aberrant or excessive activity of the complement system. Consequently, cells not directly affected by an acute event or genetic variants may degenerate, resulting in enhanced visual impairment. The therapeutic potential of supplementation of complement factor H (FH), a key regulator of the complement cascade, is therefore particularly promising in the context of retinal diseases caused by complement activation. In this study, we engineered adeno-associated viruses (AAVs) containing sequences of two truncated human FH variants. The expression of these variants was regulated by the glial fibrillary acidic protein (GFAP) promoter, which is selectively active in gliotic Müller cells. Both FH variants consisted of FH domains 19-20, which were connected to domains 1-4 and 1-7, respectively, by a polyglycine linker. These AAVs were intravitreally injected following ischemic injury of C57BL/6J mouse retinas. We observed transgene expression in gliotic Müller cells and to some extent in astrocytes. The expression correlated directly with damage severity. Interventions resulted in decreased complement activation, accelerated normalization of microglia activity and morphological improvements. Reduced levels of C3 transcripts and C3d protein in conjunction with higher transcript levels of inhibitory regulators like Cfi and Cfh, hinted at attenuated complement activity. This study demonstrates the great potential of complement regulatory gene addition therapy. With further in vivo testing it could be applied to treat a wide range of retinal diseases where no causative therapies are available.
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Affiliation(s)
- Josef Biber
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Yassin Jabri
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, Germany
| | - Sarah Glänzer
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Aaron Dort
- Experimental Ophthalmology, University of Marburg, Marburg, Germany
| | - Patricia Hoffelner
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Christoph Q Schmidt
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany
- Institute of Pharmacy, Biochemical Pharmacy Group, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Oliver Bludau
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Diana Pauly
- Experimental Ophthalmology, University of Marburg, Marburg, Germany.
| | - Antje Grosche
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
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2
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Brown LN, Barth JL, Jafri S, Rumschlag JA, Jenkins TR, Atkinson C, Lang H. Complement factor B is essential for the proper function of the peripheral auditory system. Front Neurol 2023; 14:1214408. [PMID: 37560455 PMCID: PMC10408708 DOI: 10.3389/fneur.2023.1214408] [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: 04/29/2023] [Accepted: 07/05/2023] [Indexed: 08/11/2023] Open
Abstract
Sensorineural hearing loss is associated with dysfunction of cochlear cells. Although immune cells play a critical role in maintaining the inner ear microenvironment, the precise immune-related molecular mechanisms underlying the pathophysiology of hearing loss remain unclear. The complement cascade contributes to the regulation of immune cell activity. Additionally, activation of the complement cascade can lead to the cellular opsonization of cells and pathogens, resulting in their engulfment and elimination by phagocytes. Complement factor B (fB) is an essential activator protein in the alternative complement pathway, and variations in the fB gene are associated with age-related macular degeneration. Here we show that mice of both sexes deficient in fB functional alleles (fB-/-) demonstrate progressive hearing impairment. Transcriptomic analysis of auditory nerves from adult mice detected 706 genes that were significantly differentially expressed between fB-/- and wild-type control animals, including genes related to the extracellular matrix and neural development processes. Additionally, a subset of differentially expressed genes was related to myelin function and neural crest development. Histological and immunohistochemical investigations revealed pathological alterations in auditory nerve myelin sheathes of fB-/- mice. Pathological alterations were also seen in the stria vascularis of the cochlear lateral wall in these mice. Our results implicate fB as an integral regulator of myelin maintenance and stria vascularis integrity, underscoring the importance of understanding the involvement of immune signaling pathways in sensorineural hearing loss.
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Affiliation(s)
- LaShardai N. Brown
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Jeremy L. Barth
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Shabih Jafri
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Jeffrey A. Rumschlag
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Tyreek R. Jenkins
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Carl Atkinson
- Division of Pulmonary Medicine, University of Florida, Gainesville, FL, United States
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
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3
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Kushwah N, Bora K, Maurya M, Pavlovich MC, Chen J. Oxidative Stress and Antioxidants in Age-Related Macular Degeneration. Antioxidants (Basel) 2023; 12:1379. [PMID: 37507918 PMCID: PMC10376043 DOI: 10.3390/antiox12071379] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
Oxidative stress plays a crucial role in aging-related eye diseases, including age-related macular degeneration (AMD), cataracts, and glaucoma. With age, antioxidant reparative capacity decreases, and excess levels of reactive oxygen species produce oxidative damage in many ocular cell types underling age-related pathologies. In AMD, loss of central vision in the elderly is caused primarily by retinal pigment epithelium (RPE) dysfunction and degeneration and/or choroidal neovascularization that trigger malfunction and loss of photo-sensing photoreceptor cells. Along with various genetic and environmental factors that contribute to AMD, aging and age-related oxidative damage have critical involvement in AMD pathogenesis. To this end, dietary intake of antioxidants is a proven way to scavenge free radicals and to prevent or slow AMD progression. This review focuses on AMD and highlights the pathogenic role of oxidative stress in AMD from both clinical and experimental studies. The beneficial roles of antioxidants and dietary micronutrients in AMD are also summarized.
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Affiliation(s)
| | | | | | | | - Jing Chen
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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4
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Lenin RR, Koh YH, Zhang Z, Yeo YZ, Parikh BH, Seah I, Wong W, Su X. Dysfunctional Autophagy, Proteostasis, and Mitochondria as a Prelude to Age-Related Macular Degeneration. Int J Mol Sci 2023; 24:ijms24108763. [PMID: 37240109 DOI: 10.3390/ijms24108763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
Retinal pigment epithelial (RPE) cell dysfunction is a key driving force of AMD. RPE cells form a metabolic interface between photoreceptors and choriocapillaris, performing essential functions for retinal homeostasis. Through their multiple functions, RPE cells are constantly exposed to oxidative stress, which leads to the accumulation of damaged proteins, lipids, nucleic acids, and cellular organelles, including mitochondria. As miniature chemical engines of the cell, self-replicating mitochondria are heavily implicated in the aging process through a variety of mechanisms. In the eye, mitochondrial dysfunction is strongly associated with several diseases, including age-related macular degeneration (AMD), which is a leading cause of irreversible vision loss in millions of people globally. Aged mitochondria exhibit decreased rates of oxidative phosphorylation, increased reactive oxygen species (ROS) generation, and increased numbers of mitochondrial DNA mutations. Mitochondrial bioenergetics and autophagy decline during aging because of insufficient free radical scavenger systems, the impairment of DNA repair mechanisms, and reductions in mitochondrial turnover. Recent research has uncovered a much more complex role of mitochondrial function and cytosolic protein translation and proteostasis in AMD pathogenesis. The coupling of autophagy and mitochondrial apoptosis modulates the proteostasis and aging processes. This review aims to summarise and provide a perspective on (i) the current evidence of autophagy, proteostasis, and mitochondrial dysfunction in dry AMD; (ii) current in vitro and in vivo disease models relevant to assessing mitochondrial dysfunction in AMD, and their utility in drug screening; and (iii) ongoing clinical trials targeting mitochondrial dysfunction for AMD therapeutics.
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Affiliation(s)
- Raji Rajesh Lenin
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Department of Medical Research, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - Yi Hui Koh
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Zheting Zhang
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University (NTU), 11 Mandalay Road, Experimental Medicine Building, Singapore 308232, Singapore
| | - Yan Zhuang Yeo
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Bhav Harshad Parikh
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Ivan Seah
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Wendy Wong
- Department of Ophthalmology, National University Hospital (NUH), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Xinyi Su
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Department of Ophthalmology, National University Hospital (NUH), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6 Discovery Tower, Singapore 169856, Singapore
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5
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Piri N, Kaplan HJ. Role of Complement in the Onset of Age-Related Macular Degeneration. Biomolecules 2023; 13:biom13050832. [PMID: 37238702 DOI: 10.3390/biom13050832] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive degenerative disease of the central retina and the leading cause of severe loss of central vision in people over age 50. Patients gradually lose central visual acuity, compromising their ability to read, write, drive, and recognize faces, all of which greatly impact daily life activities. Quality of life is significantly affected in these patients, and there are worse levels of depression as a result. AMD is a complex, multifactorial disease in which age and genetics, as well as environmental factors, all play a role in its development and progression. The mechanism by which these risk factors interact and converge towards AMD are not fully understood, and therefore, drug discovery is challenging, with no successful therapeutic attempt to prevent the development of this disease. In this review, we describe the pathophysiology of AMD and review the role of complement, which is a major risk factor in the development of AMD.
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Affiliation(s)
- Niloofar Piri
- Department of Ophthalmology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Henry J Kaplan
- Departments of Ophthalmology and Biochemistry & Molecular Biology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
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6
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Kaynezhad P, Tachtsidis I, Sivaprasad S, Jeffery G. Watching the human retina breath in real time and the slowing of mitochondrial respiration with age. Sci Rep 2023; 13:6445. [PMID: 37081065 PMCID: PMC10119193 DOI: 10.1038/s41598-023-32897-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/04/2023] [Indexed: 04/22/2023] Open
Abstract
The retina has the greatest metabolic demand in the body particularly in dark adaptation when its sensitivity is enhanced. This requires elevated level of perfusion to sustain mitochondrial activity. However, mitochondrial performance declines with age leading to reduced adaptive ability. We assessed human retina metabolism in vivo using broad band near-infrared spectroscopy (bNIRS), which records colour changes in mitochondria and blood as retinal metabolism shifts in response to changes in environmental luminance. We demonstrate a significant sustained rise in mitochondrial oxidative metabolism in the first 3 min of darkness in subjects under 50 years old. This was not seen in those over 50 years. Choroidal oxygenation declines in < 50 s as mitochondrial metabolism increases, but gradually rises in the > 50 s. Significant group differences in blood oxygenation are apparent in the first 6 min, consistent with mitochondrial demand leading hemodynamic changes. A greater coupling between mitochondrial oxidative metabolism with hemodynamics is revealed in subjects older than 50, possibly due to reduced capacity in the older retina. Rapid in vivo assessment of retinal metabolism with bNIRS provides a route to understanding fundamental physiology and early identification of retinal disease before pathology is established.
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Affiliation(s)
- Pardis Kaynezhad
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London, WC1E6BT, UK
| | - Sobha Sivaprasad
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK.
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7
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Kam JH, Shinhmar H, Powner MB, Hayes MJ, Aboelnour A, Jeffery G. Mitochondrial decline in the ageing old world primate retina: Little evidence for difference between the centre and periphery. PLoS One 2023; 18:e0273882. [PMID: 37130143 PMCID: PMC10153720 DOI: 10.1371/journal.pone.0273882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 04/10/2023] [Indexed: 05/03/2023] Open
Abstract
Mitochondrial decline is a key feature of ageing. The retina has more mitochondria than any other tissue and ages rapidly. To understand human retinal ageing it is critical to examine old world primates that have similar visual systems to humans, and do so across central and peripheral regions, as there is evidence for early central decline. Hence, we examine mitochondrial metrics in young and ageing Macaca fascicularis retinae. In spite of reduced ATP with age, primate mitochondrial complex activity did not decline. But mitochondrial membrane potentials were reduced significantly, and concomitantly, mitochondrial membrane permeability increased. The mitochondrial marker Tom20 declined significantly, consistent with reduced mitochondria number, while VDAC, a voltage dependent anion channel and diffusion pore associated with apoptosis increased significantly. In spite of these clear age-related changes, there was almost no evidence for regional differences between the centre and the periphery in these mitochondrial metrics. Primate cones do not die with age, but many showed marked structural decline with vacuous spaces in proximal inner segments normally occupied by endoplasmic reticulum (ER), that regulate mitochondrial autophagy. In many peripheral cones, ER was displaced by the nucleus that transposed across the outer limiting membrane and could become embedded in mitochondrial populations. These data are consistent with significant changes in retinal mitochondria in old world primate ageing but provide little if any evidence that aged central mitochondria suffer more than those in the periphery.
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Affiliation(s)
- Jaimie Hoh Kam
- Department of Visual Science, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Harpreet Shinhmar
- Department of Visual Science, Institute of Ophthalmology, University College London, London, United Kingdom
| | | | - Matthew John Hayes
- Department of Visual Science, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Asmaa Aboelnour
- Department of Histology, Damanhour University, Damanhour, Egypt
| | - Glen Jeffery
- Department of Visual Science, Institute of Ophthalmology, University College London, London, United Kingdom
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8
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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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9
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Stravalaci M, Ferrara M, Pathak V, Davi F, Bottazzi B, Mantovani A, Medina RJ, Romano MR, Inforzato A. The Long Pentraxin PTX3 as a New Biomarker and Pharmacological Target in Age-Related Macular Degeneration and Diabetic Retinopathy. Front Pharmacol 2022; 12:811344. [PMID: 35069222 PMCID: PMC8776640 DOI: 10.3389/fphar.2021.811344] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/20/2021] [Indexed: 12/12/2022] Open
Abstract
Age related macular degeneration (AMD) and diabetic retinopathy (DR) are multifactorial, neurodegenerative and inflammatory diseases of the eye primarily involving cellular and molecular components of the outer and inner blood-retina barriers (BRB), respectively. Largely contributed by genetic factors, particularly polymorphisms in complement genes, AMD is a paradigm of retinal immune dysregulation. DR, a major complication of diabetes mellitus, typically presents with increased vascular permeability and occlusion of the retinal vasculature that leads, in the proliferative form of the disease, to neovascularization, a pathogenic trait shared with advanced AMD. In spite of distinct etiology and clinical manifestations, both pathologies share common drivers, such as chronic inflammation, either of immune (in AMD) or metabolic (in DR) origin, which initiates and propagates degeneration of the neural retina, yet the underlying mechanisms are still unclear. As a soluble pattern recognition molecule with complement regulatory functions and a marker of vascular damage, long pentraxin 3 (PTX3) is emerging as a novel player in ocular homeostasis and a potential pharmacological target in neurodegenerative disorders of the retina. Physiologically present in the human eye and induced in inflammatory conditions, this protein is strategically positioned at the BRB interface, where it acts as a “molecular trap” for complement, and modulates inflammation both in homeostatic and pathological conditions. Here, we discuss current viewpoints on PTX3 and retinal diseases, with a focus on AMD and DR, the roles therein proposed for this pentraxin, and their implications for the development of new therapeutic strategies.
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Affiliation(s)
| | | | - Varun Pathak
- School of Medicine, Dentistry, and Biomedical Sciences, Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | | | | | - Alberto Mantovani
- IRCCS Humanitas Research Hospital, Rozzano, Italy.,Department of Biomedical Sciences, Humanitas University, Rozzano, Italy.,The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Reinhold J Medina
- School of Medicine, Dentistry, and Biomedical Sciences, Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Mario R Romano
- Eye Center, Humanitas Gavazzeni-Castelli, Bergamo, Italy.,Department of Biomedical Sciences, Humanitas University, Rozzano, Italy
| | - Antonio Inforzato
- IRCCS Humanitas Research Hospital, Rozzano, Italy.,Department of Biomedical Sciences, Humanitas University, Rozzano, Italy
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10
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Ormenişan DM, Borda A. Benefits of genetic and immunohistochemical markers in understanding abnormalities in aging retina. ROMANIAN JOURNAL OF MORPHOLOGY AND EMBRYOLOGY = REVUE ROUMAINE DE MORPHOLOGIE ET EMBRYOLOGIE 2022; 63:121-127. [PMID: 36074675 PMCID: PMC9593114 DOI: 10.47162/rjme.63.1.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
The aim of the study was to better understand the interplay between genetic factors and the aging process in the human retina through mapping complement factor H (CFH) and related proteins. Two human eyes, from 92- and 64-year-old donors, were genotyped for the expression of CFH-related 1 (CFHR1) and CFH-related 3 (CFHR3) genes. Deoxyribonucleic acid (DNA) was extracted and analyzed for concentration and purity with a spectrophotometer, at 260 nm. The results showed a DNA concentration of 469.17 ng∕μL in the aged retina and of 399.20 ng∕μL in the younger one. Through polymerase chain reaction (PCR) genotyping, the DNA CFHR1 and CFHR3 were visible as bands of 175 bp and 181 bp. Immunohistochemistry by immunofluorescence method was used with a panel of specific antibodies for CFH, CFHR1, CFHR3 and GFAP, a marker for Müller cells. All the samples were examined, and images captured using confocal microscopy. In the younger retina, CFH was localized in the inner plexiform layer and below the outer nuclear layer, while in the aged retina, it was found in the photoreceptors. CFH was also detected in the choriocapillaris and within the end-feet of the Müller cells. Our controls showed autofluorescence of the retinal pigment epithelium shedding light on a false positive CFH immunostaining of this layer. GFAP immunoreactivity highlighted an increased gliosis within the aged retina. CFHR3 signal was found in the microglia, while CFHR1 was detected in the choriocapillaris. In summary, underpinning the expression of these components can show the potential involvement of these modulators in implementing new treatment strategies.
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11
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Mack HG, Colville DJ, Harraka P, Savige JA, Invernizzi A, Fraser-Bell S. Retinal findings in glomerulonephritis. Clin Exp Optom 2021; 105:474-486. [PMID: 34877922 DOI: 10.1080/08164622.2021.2003691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
The complement system is part of the innate immune system activated by three distinct pathways: classical, lectin and alternative. It is also involved in retinal development and homoeostasis. Dense deposit disease is a rare renal disease associated with mutations in Complement factor H and overactivity of the alternative complement pathway. As well as glomerulonephritis, many affected individuals have retinal drusen and may be at risk of vision loss due to macular atrophy or choroidal neovascularisation. We discuss the reclassification of dense deposit disease as a type of C3 glomerulonephropathy, and hypothesise on the mechanisms of retinal abnormalities. Drusen have also been described in individuals with other types of glomerulonephritis involving abnormalities of the classical (membranoproliferative glomerulonephritis type 1) or lectin (IgA nephropathy, lupus nephritis) complement pathways. Although drusen are found in abnormalities of all three complement pathways, the age at onset, aetiology, and the threat to vision differs. This review describes drusen and other retinal abnormalities associated with the glomerulonephritides due to abnormal activation in each of the three complement activation pathways, and provides the first report of drusen occurring in a patient with the recently reclassified C3 glomerulonephritis with homozygous variant V62I in complement factor H. Optometric management of young patients presenting with retinal drusen is discussed, and complement-based therapies for visual loss are reviewed.
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Affiliation(s)
- Heather G Mack
- Department of Surgery (Ophthalmology), University of Melbourne, Melbourne, Australia.,Department of Ophthalmology, Melbourne Health, Melbourne, Australia.,Centre for Eye Research, University of Melbourne, Melbourne, Australia
| | - Deborah J Colville
- Department of Surgery (Ophthalmology), University of Melbourne, Melbourne, Australia.,Department of Ophthalmology, Melbourne Health, Melbourne, Australia
| | - Phillip Harraka
- Department of Medicine (Northern), University of Melbourne, Melbourne, Australia
| | - Judith Anne Savige
- Department of Medicine (Northern), University of Melbourne, Melbourne, Australia
| | - Alessandro Invernizzi
- Department of Biomedical and Clinical Sciences 'Luigi Sacco', University of Milan, Milan, Italy
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12
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Complement Inhibitors in Age-Related Macular Degeneration: A Potential Therapeutic Option. J Immunol Res 2021; 2021:9945725. [PMID: 34368372 PMCID: PMC8346298 DOI: 10.1155/2021/9945725] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/07/2021] [Accepted: 07/14/2021] [Indexed: 11/18/2022] Open
Abstract
Age-related macular degeneration (AMD) is a multifactorial disease, which can culminate in irreversible vision loss and blindness in elderly. Nowadays, there is a big gap between dry AMD and wet AMD on treatment. Accounting for nearly 90% of AMD, dry AMD still lacks effective treatment. Numerous genetic and molecular researches have confirmed the significant role of the complement system in the pathogenesis of AMD, leading to a deeper exploration of complement inhibitors in the treatment of AMD. To date, at least 14 different complement inhibitors have been or are being explored in AMD in almost 40 clinical trials. While most complement inhibitors fail to treat AMD successfully, two of them are effective in inhibiting the rate of GA progression in phase II clinical trials, and both of them successfully entered phase III trials. Furthermore, recently emerging complement gene therapy and combination therapy also offer new opportunities to treat AMD in the future. In this review, we aim to introduce genetic and molecular associations between the complement system and AMD, provide the updated progress in complement inhibitors in AMD on clinical trials, and discuss the challenges and prospects of complement therapeutic strategies in AMD.
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13
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Choudhury R, Bayatti N, Scharff R, Szula E, Tilakaratna V, Udsen MS, McHarg S, Askari JA, Humphries MJ, Bishop PN, Clark SJ. FHL-1 interacts with human RPE cells through the α5β1 integrin and confers protection against oxidative stress. Sci Rep 2021; 11:14175. [PMID: 34239032 PMCID: PMC8266909 DOI: 10.1038/s41598-021-93708-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 06/16/2021] [Indexed: 12/16/2022] Open
Abstract
Retinal pigment epithelial (RPE) cells that underlie the neurosensory retina are essential for the maintenance of photoreceptor cells and hence vision. Interactions between the RPE and their basement membrane, i.e. the inner layer of Bruch's membrane, are essential for RPE cell health and function, but the signals induced by Bruch's membrane engagement, and their contributions to RPE cell fate determination remain poorly defined. Here, we studied the functional role of the soluble complement regulator and component of Bruch's membrane, Factor H-like protein 1 (FHL-1). Human primary RPE cells adhered to FHL-1 in a manner that was eliminated by either mutagenesis of the integrin-binding RGD motif in FHL-1 or by using competing antibodies directed against the α5 and β1 integrin subunits. These short-term experiments reveal an immediate protein-integrin interaction that were obtained from primary RPE cells and replicated using the hTERT-RPE1 cell line. Separate, longer term experiments utilising RNAseq analysis of hTERT-RPE1 cells bound to FHL-1, showed an increased expression of the heat-shock protein genes HSPA6, CRYAB, HSPA1A and HSPA1B when compared to cells bound to fibronectin (FN) or laminin (LA). Pathway analysis implicated changes in EIF2 signalling, the unfolded protein response, and mineralocorticoid receptor signalling as putative pathways. Subsequent cell survival assays using H2O2 to induce oxidative stress-induced cell death suggest hTERT-RPE1 cells had significantly greater protection when bound to FHL-1 or LA compared to plastic or FN. These data show a non-canonical role of FHL-1 in protecting RPE cells against oxidative stress and identifies a novel interaction that has implications for ocular diseases such as age-related macular degeneration.
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Affiliation(s)
- Rawshan Choudhury
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Nadhim Bayatti
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Richard Scharff
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Ewa Szula
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Viranga Tilakaratna
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Maja Søberg Udsen
- Panum Institute, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Selina McHarg
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Janet A Askari
- Wellcome Centre for Cell-Matrix Research, Division of Cell Matrix Biology & Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Oxford, UK
| | - Martin J Humphries
- Wellcome Centre for Cell-Matrix Research, Division of Cell Matrix Biology & Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Oxford, UK
| | - Paul N Bishop
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Simon J Clark
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK.
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK.
- Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Elfriede-Aulhorn-Straße 7, 72076, Tübingen, Germany.
- University Eye Clinic, Department for Ophthalmology, University of Tübingen, Tübingen, Germany.
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14
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Armento A, Ueffing M, Clark SJ. The complement system in age-related macular degeneration. Cell Mol Life Sci 2021; 78:4487-4505. [PMID: 33751148 PMCID: PMC8195907 DOI: 10.1007/s00018-021-03796-9] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/05/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022]
Abstract
Age-related macular degeneration (AMD) is a chronic and progressive degenerative disease of the retina, which culminates in blindness and affects mainly the elderly population. AMD pathogenesis and pathophysiology are incredibly complex due to the structural and cellular complexity of the retina, and the variety of risk factors and molecular mechanisms that contribute to disease onset and progression. AMD is driven by a combination of genetic predisposition, natural ageing changes and lifestyle factors, such as smoking or nutritional intake. The mechanism by which these risk factors interact and converge towards AMD are not fully understood and therefore drug discovery is challenging, where no therapeutic attempt has been fully effective thus far. Genetic and molecular studies have identified the complement system as an important player in AMD. Indeed, many of the genetic risk variants cluster in genes of the alternative pathway of the complement system and complement activation products are elevated in AMD patients. Nevertheless, attempts in treating AMD via complement regulators have not yet been successful, suggesting a level of complexity that could not be predicted only from a genetic point of view. In this review, we will explore the role of complement system in AMD development and in the main molecular and cellular features of AMD, including complement activation itself, inflammation, ECM stability, energy metabolism and oxidative stress.
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Affiliation(s)
- Angela Armento
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.
| | - Simon J Clark
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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15
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Krytkowska E, Ulanczyk Z, Grabowicz A, Mozolewska-Piotrowska K, Safranow K, Palucha A, Krawczyk M, Sikora P, Matczynska E, Stahl A, Machalinski B, Machalinska A. Retinal Vessel Functionality Is Linked With ARMS2 A69S and CFH Y402H Polymorphisms and Choroidal Status in AMD Patients. Invest Ophthalmol Vis Sci 2021; 62:30. [PMID: 33900362 PMCID: PMC8088223 DOI: 10.1167/iovs.62.4.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We aimed to investigate the reactivity of retinal vessels to a flickering stimulus in patients with age-related macular degeneration (AMD) and healthy participants. We also assessed whether the parameters of retinal vessels are dependent on genetic predisposition. Methods A total of 354 patients with AMD and 121 controls were recruited for the study. All participants underwent thorough ophthalmologic examination and static and dynamic retinal vessel analysis. AMD risk polymorphisms were genotyped in the CFH and ARMS2 genes. Results We found no differences between the AMD group and controls in central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), arteriovenous ratio (AVR), dynamic analysis of arteries (DAAs), or dynamic analysis of veins (DAVs). Eyes with early AMD presented with significantly higher AVR values than eyes with late AMD. In the AMD group, DAA correlated positively with both choroidal thickness (Rs = 0.14, P = 0.00096) and choroidal volume (Rs = 0.23, P < 0.0001), and no such associations were observed in the controls. We found significantly lower DAA (1.47 ± 1.50) in TT homozygotes for the ARMS2 A69S polymorphism in comparison with GG homozygotes (2.38 ± 1.79) and patients with GG + GT genotypes (2.28 ± 1.84). We also observed less prominent DAV (3.24 ± 1.71) in patients with TC + CC genotypes in the CFH Y402H polymorphism compared with TT homozygotes (3.83 ± 1.68). Conclusions Our findings suggest that retinal microcirculation appears to be associated with the genetic background, choroidal parameters, and clinical features of the patients with AMD.
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Affiliation(s)
- Elzbieta Krytkowska
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin, Poland
| | - Zofia Ulanczyk
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Aleksandra Grabowicz
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin, Poland
| | | | - Krzysztof Safranow
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Szczecin, Poland
| | | | | | | | | | - Andreas Stahl
- Department of Ophthalmology, University Medicine Greifswald, Greifswald, Germany
| | - Boguslaw Machalinski
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Anna Machalinska
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin, Poland
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16
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Ebeling MC, Geng Z, Kapphahn RJ, Roehrich H, Montezuma SR, Dutton JR, Ferrington DA. Impaired Mitochondrial Function in iPSC-Retinal Pigment Epithelium with the Complement Factor H Polymorphism for Age-Related Macular Degeneration. Cells 2021; 10:cells10040789. [PMID: 33918210 PMCID: PMC8066149 DOI: 10.3390/cells10040789] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 12/27/2022] Open
Abstract
Age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, is characterized by loss of the retinal pigment epithelium (RPE). While the disease mechanism remains unclear, prior studies have linked AMD with RPE mitochondrial defects and genetic polymorphisms in the complement pathway. This study used RPE generated from induced pluripotent stem cells (iPSC-RPE), which were derived from human donors with or without AMD and genotyped for the complement factor H (CFH) AMD high-risk allele (rs1061170, Y402H) to investigate whether donor disease state or genotype had a detrimental effect on mitochondrial function and inflammation. Results show that cells derived from donors with AMD display decreased mitochondrial function under conditions of stress and elevated expression of inflammatory markers compared to iPSC-RPE from individuals without AMD. A more pronounced reduction in mitochondrial function and increased inflammatory markers was observed in CFH high-risk cells, irrespective of disease state. These results provide evidence for a previously unrecognized link between CFH and mitochondrial function that could contribute to RPE loss in AMD patients harboring the CFH high-risk genotype.
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Affiliation(s)
- Mara C. Ebeling
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - Zhaohui Geng
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rebecca J. Kapphahn
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - Heidi Roehrich
- Histology Core for Vision Research, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - James R. Dutton
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
- Correspondence: (J.R.D.); (D.A.F.); Tel.: +1-612-626-2762 (J.R.D.); +1-612-624-8267 (D.A.F.)
| | - Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Correspondence: (J.R.D.); (D.A.F.); Tel.: +1-612-626-2762 (J.R.D.); +1-612-624-8267 (D.A.F.)
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17
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de Jong S, Gagliardi G, Garanto A, de Breuk A, Lechanteur YTE, Katti S, van den Heuvel LP, Volokhina EB, den Hollander AI. Implications of genetic variation in the complement system in age-related macular degeneration. Prog Retin Eye Res 2021; 84:100952. [PMID: 33610747 DOI: 10.1016/j.preteyeres.2021.100952] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/08/2021] [Accepted: 02/11/2021] [Indexed: 12/23/2022]
Abstract
Age-related macular degeneration (AMD) is the main cause of vision loss among the elderly in the Western world. While AMD is a multifactorial disease, the complement system was identified as one of the main pathways contributing to disease risk. The strong link between the complement system and AMD was demonstrated by genetic associations, and by elevated complement activation in local eye tissue and in the systemic circulation of AMD patients. Several complement inhibitors have been and are being explored in clinical trials, but thus far with limited success, leaving the majority of AMD patients without treatment options to date. This indicates that there is still a gap of knowledge regarding the functional implications of the complement system in AMD pathogenesis and how to bring these towards clinical translation. Many different experimental set-ups and disease models have been used to study complement activation in vivo and in vitro, and recently emerging patient-derived induced pluripotent stem cells and genome-editing techniques open new opportunities to study AMD disease mechanisms and test new therapeutic strategies in the future. In this review we provide an extensive overview of methods employed to understand the molecular processes of complement activation in AMD pathogenesis. We discuss the findings, advantages and challenges of each approach and conclude with an outlook on how recent, exciting developments can fill in current knowledge gaps and can aid in the development of effective complement-targeting therapeutic strategies in AMD.
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Affiliation(s)
- Sarah de Jong
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands
| | - Giuliana Gagliardi
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands
| | - Alejandro Garanto
- Department of Human Genetics, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Department of Pediatrics, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Amalia Children's Hospital, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands
| | - Anita de Breuk
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands
| | - Yara T E Lechanteur
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands
| | - Suresh Katti
- Gemini Therapeutics Inc., Cambridge, MA, 02139, USA
| | - Lambert P van den Heuvel
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Amalia Children's Hospital, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Department of Laboratory Medicine, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands
| | - Elena B Volokhina
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Amalia Children's Hospital, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Department of Laboratory Medicine, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands
| | - Anneke I den Hollander
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands; Department of Human Genetics, Radboud University Medical Center, 6525, GA, Nijmegen, the Netherlands.
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18
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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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19
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The Impact of Oxidative Stress on Blood-Retinal Barrier Physiology in Age-Related Macular Degeneration. Cells 2021; 10:cells10010064. [PMID: 33406612 PMCID: PMC7823525 DOI: 10.3390/cells10010064] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/26/2020] [Accepted: 12/30/2020] [Indexed: 02/06/2023] Open
Abstract
The blood retinal barrier (BRB) is a fundamental eye component, whose function is to select the flow of molecules from the blood to the retina and vice-versa, and its integrity allows the maintenance of a finely regulated microenvironment. The outer BRB, composed by the choriocapillaris, the Bruch's membrane, and the retinal pigment epithelium, undergoes structural and functional changes in age-related macular degeneration (AMD), the leading cause of blindness worldwide. BRB alterations lead to retinal dysfunction and neurodegeneration. Several risk factors have been associated with AMD onset in the past decades and oxidative stress is widely recognized as a key factor, even if the exact AMD pathophysiology has not been exactly elucidated yet. The present review describes the BRB physiology, the BRB changes occurring in AMD, the role of oxidative stress in AMD with a focus on the outer BRB structures. Moreover, we propose the use of cerium oxide nanoparticles as a new powerful anti-oxidant agent to combat AMD, based on the relevant existing data which demonstrated their beneficial effects in protecting the outer BRB in animal models of AMD.
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20
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Ghareeb AE, Lako M, Steel DH. Coculture techniques for modeling retinal development and disease, and enabling regenerative medicine. Stem Cells Transl Med 2020; 9:1531-1548. [PMID: 32767661 PMCID: PMC7695644 DOI: 10.1002/sctm.20-0201] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/22/2020] [Accepted: 07/05/2020] [Indexed: 12/14/2022] Open
Abstract
Stem cell‐derived retinal organoids offer the opportunity to cure retinal degeneration of wide‐ranging etiology either through the study of in vitro models or the generation of tissue for transplantation. However, despite much work in animals and several human pilot studies, satisfactory therapies have not been developed. Two major challenges for retinal regenerative medicine are (a) physical cell‐cell interactions, which are critical to graft function, are not formed and (b) the host environment does not provide suitable queues for development. Several strategies offer to improve the delivery, integration, maturation, and functionality of cell transplantation. These include minimally invasive delivery, biocompatible material vehicles, retinal cell sheets, and optogenetics. Optimizing several variables in animal models is practically difficult, limited by anatomical and disease pathology which is often different to humans, and faces regulatory and ethical challenges. High‐throughput methods are needed to experimentally optimize these variables. Retinal organoids will be important to the success of these models. In their current state, they do not incorporate a representative retinal pigment epithelium (RPE)‐photoreceptor interface nor vascular elements, which influence the neural retina phenotype directly and are known to be dysfunctional in common retinal diseases such as age‐related macular degeneration. Advanced coculture techniques, which emulate the RPE‐photoreceptor and RPE‐Bruch's‐choriocapillaris interactions, can incorporate disease‐specific, human retinal organoids and overcome these drawbacks. Herein, we review retinal coculture models of the neural retina, RPE, and choriocapillaris. We delineate the scientific need for such systems in the study of retinal organogenesis, disease modeling, and the optimization of regenerative cell therapies for retinal degeneration.
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Affiliation(s)
- Ali E Ghareeb
- Sunderland Eye Infirmary, South Tyneside and Sunderland NHS Foundation Trust, Sunderland, UK.,Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, UK
| | - Majlinda Lako
- Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, UK
| | - David H Steel
- Sunderland Eye Infirmary, South Tyneside and Sunderland NHS Foundation Trust, Sunderland, UK.,Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, UK
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21
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Sabry DA. Comparative study about ageing effect on retina and cerebellum of
Columba livia domestica. ACTA ZOOL-STOCKHOLM 2020. [DOI: 10.1111/azo.12347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dalia A. Sabry
- Zoology Department Faculty of Science Mansoura University Mansoura Egypt
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22
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Wright C, Mazzucco AE, Becker SM, Sieving PA, Tumminia SJ. NEI-Supported Age-Related Macular Degeneration Research: Past, Present, and Future. Transl Vis Sci Technol 2020; 9:49. [PMID: 32832254 PMCID: PMC7414643 DOI: 10.1167/tvst.9.7.49] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/08/2020] [Indexed: 12/15/2022] Open
Abstract
Purpose To review past and current National Eye Institute (NEI)–supported age-related macular degeneration (AMD) activities and initiatives and preview upcoming coordinated efforts for studying AMD. Methods We conducted and summarized a portfolio analysis and literature review of NEI intramural and extramural AMD activities. Results The NEI supports a broad range of AMD research, both by individual independent investigators as well as through networks and consortia. The International AMD Genomics Consortium, Age-Related Eye Disease Study, Age-Related Eye Disease Study 2 (AREDS2), and Comparison of AMD Treatments Trial legacy work probed the complex genetics, clinical presentation, and standards of patient care, respectively. The NEI AMD Pathobiology Working Group identified gaps and opportunities for future research efforts. The AMD Ryan Initiative Study and clinical trials testing the efficacies of minocycline to modulate retinal microglia activity and induced pluripotent stem cells–derived retinal pigmented epithelium (RPE) patch implants to rescue photoreceptor cell death are among the future directions for NEI-supported AMD research. Finally, NEI commissioned the creation of AREDS2 participant-derived induced pluripotent stem cell (iPSC) lines linked to their associated genomic and phenotypic datasets. These datasets will also be linked to the data obtained using their associated iPSC-derived cells (RPE, retina, choroid) and made publicly available. Conclusions Investments by NEI for AMD research will continue to provide invaluable resources to investigators committed to addressing this complex blinding disease and other retinal degenerative diseases. Translational Relevance NEI now stands poised to expand the resources available to clinical investigators to uncover disease mechanisms and move experimental therapies into clinical trials.
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Affiliation(s)
- Charles Wright
- Division of Extramural Science Programs, National Eye Institute, Bethesda, MD, USA
| | - Anna E Mazzucco
- Immediate Office of the Director, National Institutes of Health, Bethesda, MD, USA
| | - Steven M Becker
- Office of the Director, National Eye Institute, Bethesda, MD, USA
| | - Paul A Sieving
- Previous Director, National Eye Institute, Bethesda, MD, USA.,Ophthalmology and Vision Science, University of California, Davis, Davis, CA, USA
| | - Santa J Tumminia
- Office of the Director, National Eye Institute, Bethesda, MD, USA
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23
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Loss of Complement Factor H impairs antioxidant capacity and energy metabolism of human RPE cells. Sci Rep 2020; 10:10320. [PMID: 32587311 PMCID: PMC7316856 DOI: 10.1038/s41598-020-67292-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/19/2020] [Indexed: 12/28/2022] Open
Abstract
Polymorphisms in the Complement Factor H (CFH) gene, coding for the Factor H protein (FH), can increase the risk for age-related macular degeneration (AMD). AMD-associated CFH risk variants, Y402H in particular, impair FH function leading to complement overactivation. Whether this alone suffices to trigger AMD pathogenesis remains unclear. In AMD, retinal homeostasis is compromised due to the dysfunction of retinal pigment epithelium (RPE) cells. To investigate the impact of endogenous FH loss on RPE cell balance, we silenced CFH in human hTERT-RPE1 cells. FH reduction led to accumulation of C3, at both RNA and protein level and increased RPE vulnerability toward oxidative stress. Mild hydrogen-peroxide exposure in combination with CFH knock-down led to a reduction of glycolysis and mitochondrial respiration, paralleled by an increase in lipid peroxidation, which is a key aspect of AMD pathogenesis. In parallel, cell viability was decreased. The perturbations of energy metabolism were accompanied by transcriptional deregulation of several glucose metabolism genes as well as genes modulating mitochondrial stability. Our data suggest that endogenously produced FH contributes to transcriptional and metabolic homeostasis and protects RPE cells from oxidative stress, highlighting a novel role of FH in AMD pathogenesis.
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24
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Eells JT. Mitochondrial Dysfunction in the Aging Retina. BIOLOGY 2019; 8:biology8020031. [PMID: 31083549 PMCID: PMC6627398 DOI: 10.3390/biology8020031] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/04/2019] [Accepted: 05/09/2019] [Indexed: 12/21/2022]
Abstract
Mitochondria are central in retinal cell function and survival and they perform functions that are critical to cell function. Retinal neurons have high energy requirements, since large amounts of ATP are needed to generate membrane potentials and power membrane pumps. Mitochondria over the course of aging undergo a number of changes. Aged mitochondria exhibit decreased rates of oxidative phosphorylation, increased reactive oxygen species (ROS) generation and increased numbers of mtDNA mutations. Mitochondria in the neural retina and the retinal pigment epithelium are particularly susceptible to oxidative damage with aging. Many age-related retinal diseases, including glaucoma and age-related macular degeneration, have been associated with mitochondrial dysfunction. Therefore, mitochondria are a promising therapeutic target for the treatment of retinal disease.
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Affiliation(s)
- Janis T Eells
- Department of Biomedical Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA.
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25
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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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