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Mehrzadi S, Hemati K, Reiter RJ, Hosseinzadeh A. Mitochondrial dysfunction in age-related macular degeneration: melatonin as a potential treatment. Expert Opin Ther Targets 2020; 24:359-378. [PMID: 32116056 DOI: 10.1080/14728222.2020.1737015] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Introduction: Age-related Macular Degeneration (AMD), a retinal neurodegenerative disease is the most common cause of blindness among the elderly in developed countries. The impairment of mitochondrial biogenesis has been reported in human retinal pigment epithelium (RPE) cells affected by AMD. Oxidative/nitrosative stress plays an important role in AMD development. The mitochondrial respiratory system is considered a major site of reactive oxygen species (ROS) generation. During aging, insufficient free radical scavenger systems, impairment of DNA repair mechanisms and reduction of mitochondrial degradation and turnover contribute to the massive accumulation of ROS disrupting mitochondrial function. Impaired mitochondrial function leads to the decline in the autophagic capacity and induction of inflammation and apoptosis in human RPE cells affected by AMD.Areas covered: This article evaluates the ameliorative effect of melatonin on AMD and examines AMD pathogenesis with an emphasis on mitochondrial dysfunction. It also considers the potential effects of melatonin on mitochondrial function.Expert opinion: The effect of melatonin on mitochondrial function results in the reduction of oxidative stress, inflammation and apoptosis in the retina; these findings demonstrate that melatonin has the potential to prevent and treat AMD.
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Affiliation(s)
- Saeed Mehrzadi
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Karim Hemati
- Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran
| | - Russel J Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Azam Hosseinzadeh
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
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52
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Ferrington DA, Fisher CR, Kowluru RA. Mitochondrial Defects Drive Degenerative Retinal Diseases. Trends Mol Med 2020; 26:105-118. [PMID: 31771932 PMCID: PMC6938541 DOI: 10.1016/j.molmed.2019.10.008] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/16/2019] [Accepted: 10/23/2019] [Indexed: 01/08/2023]
Abstract
Mitochondrial dysfunction is involved in the pathology of two major blinding retinal diseases, diabetic retinopathy (DR) and age-related macular degeneration (AMD). These diseases accumulate mitochondrial defects in distinct retinal subcellular structures, the vascular/neural network in DR and the retinal pigment epithelium (RPE) in AMD. These mitochondrial defects cause a metabolic crisis that drives disease. With no treatments to stop these diseases, coupled with an increasing population suffering from AMD and DR, there is an urgent need to develop new therapeutics targeting the mitochondria to prevent or reverse disease-specific pathology.
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Affiliation(s)
- Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences and Graduate Program in Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| | - Cody R Fisher
- Department of Ophthalmology and Visual Neurosciences and Graduate Program in Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Renu A Kowluru
- Ophthalmology, Vision, and Anatomical Sciences, Wayne State University, Detroit, MI, USA.
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53
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Handa JT, Bowes Rickman C, Dick AD, Gorin MB, Miller JW, Toth CA, Ueffing M, Zarbin M, Farrer LA. A systems biology approach towards understanding and treating non-neovascular age-related macular degeneration. Nat Commun 2019; 10:3347. [PMID: 31350409 PMCID: PMC6659646 DOI: 10.1038/s41467-019-11262-1] [Citation(s) in RCA: 168] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 07/03/2019] [Indexed: 12/20/2022] Open
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly in the developed world. While treatment is effective for the neovascular or “wet” form of AMD, no therapy is successful for the non-neovascular or “dry” form. Here we discuss the current knowledge on dry AMD pathobiology and propose future research directions that would expedite the development of new treatments. In our view, these should emphasize system biology approaches that integrate omic, pharmacological, and clinical data into mathematical models that can predict disease onset and progression, identify biomarkers, establish disease causing mechanisms, and monitor response to therapy. No effective therapies exist for dry age-related macular degeneration. In this perspective, the authors propose that research should emphasize system biology approaches that integrate various ‘omics’ data into mathematical models to establish pathogenic mechanisms on which to design novel treatments, and identify biomarkers that predict disease progression and therapeutic response.
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Affiliation(s)
- James T Handa
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, 21287, MD, USA.
| | - Cathy Bowes Rickman
- Department of Ophthalmology, Duke University Medical Center, Durham, 27708, NC, USA
| | - Andrew D Dick
- Translational Health Sciences (Ophthalmology), University of Bristol, Bristol, BS8 1TH, UK.,University College London, Institute of Ophthalmology and the National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital and UCL-Institute of Ophthalmology, London, WC1E 6BT, UK
| | - Michael B Gorin
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA, Los Angeles, 90095, CA, USA.,Brain Research Institute, UCLA, Los Angeles, 90095, CA, USA
| | - Joan W Miller
- Retina Service, Massachusetts Eye and Ear, Harvard Ophthalmology AMD Center of Excellence, Department of Ophthalmology, Harvard Medical School, Boston, 02114, MA, USA
| | - Cynthia A Toth
- Department of Ophthalmology, Duke University Medical Center, Durham, 27708, NC, USA
| | - Marius Ueffing
- Department of Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, D-72076, Germany
| | - Marco Zarbin
- Institute of Ophthalmology and Visual Science, New Jersey Medical School, Rutgers University, Newark, 07103, NJ, USA
| | - Lindsay A Farrer
- Departments of Medicine (Biomedical Genetics), Neurology, Ophthalmology, Epidemiology, and Biostatistics, Boston University Schools of Medicine and Public Health, Boston, 02118, MA, USA.
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54
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Role of Mitochondrial DNA Damage in ROS-Mediated Pathogenesis of Age-Related Macular Degeneration (AMD). Int J Mol Sci 2019; 20:ijms20102374. [PMID: 31091656 PMCID: PMC6566654 DOI: 10.3390/ijms20102374] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/17/2019] [Accepted: 04/28/2019] [Indexed: 12/19/2022] Open
Abstract
Age-related macular degeneration (AMD) is a complex eye disease that affects millions of people worldwide and is the main reason for legal blindness and vision loss in the elderly in developed countries. Although the cause of AMD pathogenesis is not known, oxidative stress-related damage to retinal pigment epithelium (RPE) is considered an early event in AMD induction. However, the precise cause of such damage and of the induction of oxidative stress, including related oxidative effects occurring in RPE and the onset and progression of AMD, are not well understood. Many results point to mitochondria as a source of elevated levels of reactive oxygen species (ROS) in AMD. This ROS increase can be associated with aging and effects induced by other AMD risk factors and is correlated with damage to mitochondrial DNA. Therefore, mitochondrial DNA (mtDNA) damage can be an essential element of AMD pathogenesis. This is supported by many studies that show a greater susceptibility of mtDNA than nuclear DNA to DNA-damaging agents in AMD. Therefore, the mitochondrial DNA damage reaction (mtDDR) is important in AMD prevention and in slowing down its progression as is ROS-targeting AMD therapy. However, we know far less about mtDNA than its nuclear counterparts. Further research should measure DNA damage in order to compare it in mitochondria and the nucleus, as current methods have serious disadvantages.
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55
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Antimycin A-Induced Mitochondrial Damage Causes Human RPE Cell Death despite Activation of Autophagy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:1583656. [PMID: 31007832 PMCID: PMC6441541 DOI: 10.1155/2019/1583656] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/01/2018] [Indexed: 01/20/2023]
Abstract
Mitochondrial dysfunction has been implicated in a wide variety of degenerative diseases, including age-related macular degeneration. Damage to mitochondria and mitochondrial DNA accumulates with age in the postmitotic retinal pigment epithelium (RPE), which could lead to RPE cell death and trigger disease. One possible mechanism for cells to avoid cell death is mitophagy, the targeted clearance of damaged mitochondria by autophagy. Here, we induced mitochondrial damage in human RPE cells (ARPE-19 and hRPE), using antimycin A, an inhibitor of complex III of the electron transport chain, and investigated cellular viability, mitochondrial structure and function, and autophagy activity. We observed that antimycin A evoked dose-dependent cell death, a rapid loss in mitochondrial membrane potential, and a collapse of oxidative phosphorylation. Mitochondria appeared swollen and there was clear damage to their cristae structure. At the same time, cells were undergoing active autophagy and were sensitive to autophagy inhibition by bafilomycin A1 or chloroquine. These results indicate that mitochondrial dysfunction can cause significant RPE damage and that autophagy is an important survival mechanism for cells suffering from mitochondrial damage.
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56
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Tan ACS, Pilgrim MG, Fearn S, Bertazzo S, Tsolaki E, Morrell AP, Li M, Messinger JD, Dolz-Marco R, Lei J, Nittala MG, Sadda SR, Lengyel I, Freund KB, Curcio CA. Calcified nodules in retinal drusen are associated with disease progression in age-related macular degeneration. Sci Transl Med 2018; 10:eaat4544. [PMID: 30404862 PMCID: PMC10721335 DOI: 10.1126/scitranslmed.aat4544] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 08/10/2018] [Accepted: 10/17/2018] [Indexed: 12/17/2023]
Abstract
Drusen are lipid-, mineral-, and protein-containing extracellular deposits that accumulate between the basal lamina of the retinal pigment epithelium (RPE) and Bruch's membrane (BrM) of the human eye. They are a defining feature of age-related macular degeneration (AMD), a common sight-threatening disease of older adults. The appearance of heterogeneous internal reflectivity within drusen (HIRD) on optical coherence tomography (OCT) images has been suggested to indicate an increased risk of progression to advanced AMD. Here, in a cohort of patients with AMD and drusen, we show that HIRD indicated an increased risk of developing advanced AMD within 1 year. Using multimodal imaging in an independent cohort, we demonstrate that progression to AMD was associated with increasing degeneration of the RPE overlying HIRD. Morphological analysis of clinically imaged cadaveric human eye samples revealed that HIRD was formed by multilobular nodules. Nanoanalytical methods showed that nodules were composed of hydroxyapatite and that they differed from spherules and BrM plaques, other refractile features also found in the retinas of patients with AMD. These findings suggest that hydroxyapatite nodules may be indicators of progression to advanced AMD and that using multimodal clinical imaging to determine the composition of macular calcifications may help to direct therapeutic strategies and outcome measures in AMD.
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Affiliation(s)
- Anna C S Tan
- Vitreous Retina Macula Consultants of New York, New York, NY 10022, USA
- LuEsther T. Mertz Retinal Research Center, Manhattan, Eye, Ear and Throat Hospital, New York, NY 10075, USA
- Singapore National Eye Center/Singapore Eye Research Institute Singapore, Singapore 168751, Singapore
- Duke-NUS Singapore, Singapore 168751, Singapore
| | - Matthew G Pilgrim
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London WC1X 8LD, UK
| | - Sarah Fearn
- Department of Materials, Imperial College London, London SW7 2AZ, UK
| | - Sergio Bertazzo
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London WC1E 6BT, UK
| | - Elena Tsolaki
- Department of Medical Physics and Biomedical Engineering, University College London, Malet Place Engineering Building, London WC1E 6BT, UK
| | - Alexander P Morrell
- Material Physics, Aston University, Aston Express Way, Birmingham B4 7ET, UK
| | - Miaoling Li
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 32594-0019, USA
| | - Jeffrey D Messinger
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 32594-0019, USA
| | - Rosa Dolz-Marco
- Vitreous Retina Macula Consultants of New York, New York, NY 10022, USA
- LuEsther T. Mertz Retinal Research Center, Manhattan, Eye, Ear and Throat Hospital, New York, NY 10075, USA
| | - Jianqin Lei
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, CA 90033, USA
| | - Muneeswar G Nittala
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, CA 90033, USA
| | - Srinivas R Sadda
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, CA 90033, USA
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Imre Lengyel
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK.
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, UK
| | - K Bailey Freund
- Vitreous Retina Macula Consultants of New York, New York, NY 10022, USA
- LuEsther T. Mertz Retinal Research Center, Manhattan, Eye, Ear and Throat Hospital, New York, NY 10075, USA
- Department of Ophthalmology, New York University Langone School of Medicine, New York, NY 10016, USA
| | - Christine A Curcio
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 32594-0019, USA
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57
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Schori C, Trachsel C, Grossmann J, Zygoula I, Barthelmes D, Grimm C. The Proteomic Landscape in the Vitreous of Patients With Age-Related and Diabetic Retinal Disease. Invest Ophthalmol Vis Sci 2018; 59:AMD31-AMD40. [PMID: 30025106 DOI: 10.1167/iovs.18-24122] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose In contrast to neovascular AMD (nAMD), no treatment option exists for dry AMD. Hence, the identification of specific biomarkers is required to facilitate diagnosis and therapy of dry AMD. Methods The proteome of 34 vitreous humor samples (dry AMD: n = 6; nAMD: n = 10; proliferative diabetic retinopathy [PDR]: n = 9; epiretinal membrane [ERM]: n = 9) was analyzed by liquid chromatography coupled mass spectrometry. Then, label-free relative quantification of dry AMD, nAMD, and PDR relative to ERM, which was defined as the reference group, was performed. Application of a bioinformatics pipeline further analyzed the vitreous proteome by cluster and gene set enrichment analysis. A selection of differentially regulated proteins was validated by ELISA. Results A total of 677 proteins were identified in the vitreous of the four patient groups and quantified relatively to ERM. Different clusters of regulated proteins for each patient group were identified and showed characteristic enrichment of specific pathways including "oxidative stress" for dry AMD, "focal adhesion" for nAMD, and "complement and coagulation cascade" for PDR patients. We identified cholinesterase (CHLE) to be specifically upregulated in dry AMD and ribonuclease (pancreatic; RNAS1) together with serine carboxypeptidase (probable; CPVL) to be upregulated in both forms of AMD. Conclusions The described pathways specific for the different patient groups and the identification of characteristic differentially regulated proteins provide a first step toward the definition of biomarkers for dry AMD. The presented data will facilitate the investigation of mechanistic connections of proteins to the respective disease.
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Affiliation(s)
- Christian Schori
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Zurich, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Christian Trachsel
- Functional Genomics Center Zurich (FGCZ), ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Jonas Grossmann
- Functional Genomics Center Zurich (FGCZ), ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Ioanna Zygoula
- Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland
| | - Daniel Barthelmes
- Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland.,Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Christian Grimm
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Zurich, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich, Zurich, Switzerland
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58
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Feng Y, Madungwe NB, Bopassa JC. Mitochondrial inner membrane protein, Mic60/mitofilin in mammalian organ protection. J Cell Physiol 2018; 234:3383-3393. [PMID: 30259514 DOI: 10.1002/jcp.27314] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 08/02/2018] [Indexed: 12/13/2022]
Abstract
The identification of the mitochondrial contact site and cristae organizing system (MICOS) in the inner mitochondrial membrane shed light on the intricate components necessary for mitochondria to form their signature cristae in which many protein complexes including the electron transport chain are localized. Mic60/mitofilin has been described as the core component for the assembly and maintenance of MICOS, thus controlling cristae morphology, protein transport, mitochondrial DNA transcription, as well as connecting the inner and outer mitochondrial membranes. Although Mic60 homologs are present in many species, mammalian Mic60 is only recently gaining attention as a critical player in several organ systems and diseases with mitochondrial-defect origins. In this review, we summarize what is currently known about the ever-expanding role of Mic60 in mammals, and highlight some new studies pushing the field of mitochondrial cristae organization towards potentially new and exciting therapies targeting this protein.
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Affiliation(s)
- Yansheng Feng
- Department of Cellular and Integrative Physiology, School of Medicine, University of Texas Health Science Center at San Antonio, Texas.,Department of Pathophysiology, Xinxiang Medical University, Xinxiang, China
| | - Ngonidzashe B Madungwe
- Department of Cellular and Integrative Physiology, School of Medicine, University of Texas Health Science Center at San Antonio, Texas.,Department of Biomedical Engineering, University of Texas at San Antonio, Texas
| | - Jean C Bopassa
- Department of Cellular and Integrative Physiology, School of Medicine, University of Texas Health Science Center at San Antonio, Texas
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59
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Kaarniranta K, Kajdanek J, Morawiec J, Pawlowska E, Blasiak J. PGC-1α Protects RPE Cells of the Aging Retina against Oxidative Stress-Induced Degeneration through the Regulation of Senescence and Mitochondrial Quality Control. The Significance for AMD Pathogenesis. Int J Mol Sci 2018; 19:ijms19082317. [PMID: 30087287 PMCID: PMC6121367 DOI: 10.3390/ijms19082317] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/18/2018] [Accepted: 08/05/2018] [Indexed: 02/07/2023] Open
Abstract
PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) is a transcriptional coactivator of many genes involved in energy management and mitochondrial biogenesis. PGC-1α expression is associated with cellular senescence, organismal aging, and many age-related diseases, including AMD (age-related macular degeneration), an important global issue concerning vision loss. We and others have developed a model of AMD pathogenesis, in which stress-induced senescence of retinal pigment epithelium (RPE) cells leads to AMD-related pathological changes. PGC-1α can decrease oxidative stress, a key factor of AMD pathogenesis related to senescence, through upregulation of antioxidant enzymes and DNA damage response. PGC-1α is an important regulator of VEGF (vascular endothelial growth factor), which is targeted in the therapy of wet AMD, the most devastating form of AMD. Dysfunction of mitochondria induces cellular senescence associated with AMD pathogenesis. PGC-1α can improve mitochondrial biogenesis and negatively regulate senescence, although this function of PGC-1α in AMD needs further studies. Post-translational modifications of PGC-1α by AMPK (AMP kinase) and SIRT1 (sirtuin 1) are crucial for its activation and important in AMD pathogenesis.
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Affiliation(s)
- Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, 70211 Kuopio, Finland.
- Department of Ophthalmology, Kuopio University Hospital, 70029 Kuopio, Finland.
| | - Jakub Kajdanek
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
| | - Jan Morawiec
- Department of General and Colorectal Surgery, Medical University of Lodz, Pl. Hallera 1, 90-647 Lodz, Poland.
| | - Elzbieta Pawlowska
- Department of Orthodontics, Medical University of Lodz, Pomorska 251, 92-216 Lodz, Poland.
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
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60
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Fisher CR, Ferrington DA. Perspective on AMD Pathobiology: A Bioenergetic Crisis in the RPE. Invest Ophthalmol Vis Sci 2018; 59:AMD41-AMD47. [PMID: 30025108 PMCID: PMC5989860 DOI: 10.1167/iovs.18-24289] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
AMD is the leading cause of blindness in developed countries. The dry form of AMD, also known as atrophic AMD, is characterized by the death of RPE and photoreceptors. Currently, there are no treatments for this form of the disease due in part to our incomplete understanding of the mechanism causing AMD. Strong experimental evidence from studies of human donors with AMD supports the emerging hypothesis that defects in RPE mitochondria drive AMD pathology. These studies, using different experimental methods, have shown disrupted RPE mitochondrial architecture and decreased mitochondrial number and mass, altered content of multiple mitochondrial proteins, increased mitochondrial DNA damage that correlates with disease severity, and defects in bioenergetics for primary RPE cultures from AMD donors. Herein, we discuss a model of metabolic uncoupling that alters bioenergetics in the diseased retina and drives AMD pathology. These data provide the rationale for targeting the mitochondria in the RPE as the most efficacious intervention strategy if administered early, before vision loss and cell death.
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Affiliation(s)
- Cody R. Fisher
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States
,Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States
| | - Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States
,Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States
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61
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Beranova-Giorgianni S, Giorgianni F. Proteomics of Human Retinal Pigment Epithelium (RPE) Cells. Proteomes 2018; 6:proteomes6020022. [PMID: 29762536 PMCID: PMC6027133 DOI: 10.3390/proteomes6020022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/08/2018] [Accepted: 05/11/2018] [Indexed: 12/14/2022] Open
Abstract
Retinal pigment epithelium (RPE) are specialized, multifunctional cells in the retina that form a monolayer of cuboidal, polarized cells adjoining the photoreceptor cells. The RPE are a critical component of the blood-retinal barrier, and they play essential functional roles for maintenance of retinal homeostasis and for support and health of photoreceptors. Age-dependent, progressive dysfunction and death of RPE cells and the resultant loss of photoreceptors contribute significantly to the development and progression of age-related macular degeneration (AMD) and other retinal degenerative diseases. Several different RPE cell culture models have been developed and utilized extensively as surrogates for cellular and molecular examinations of the RPE, and a large body of knowledge on RPE function in normal and pathological scenarios has been amassed in studies with cultured RPE. Proteomics has been an integral part of research efforts aimed to advance our understanding of RPE cell biology in health and disease. This review focuses on applications of proteomics to in vitro qualitative and quantitative investigation of human RPE cell culture models. The disease context discussed focuses on AMD.
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Affiliation(s)
- Sarka Beranova-Giorgianni
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
| | - Francesco Giorgianni
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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62
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Kaarniranta K, Xu H, Kauppinen A. Mechanistical retinal drug targets and challenges. Adv Drug Deliv Rev 2018; 126:177-184. [PMID: 29698626 DOI: 10.1016/j.addr.2018.04.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/27/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022]
Abstract
The retina is constantly exposed to light that increases reactive oxygen species in retina. Oxidative stress, inflammation and neurodegeneration are the major contributors in the most common retinal diseases, such as age-related macular degeneration (AMD), glaucoma and diabetic retinopathy (DR). Emerging developments and research for novel therapy targets and drug delivery to the posterior segment offer a promising future for the treatment of retinal diseases including rare hereditary diseases. In this review we discuss about promising mechanistical retinal drug targets. Vascular endothelial growth factor (VEGF) signaling and anti-VEGF treatments are excluded.
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63
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Ao J, Wood JP, Chidlow G, Gillies MC, Casson RJ. Retinal pigment epithelium in the pathogenesis of age-related macular degeneration and photobiomodulation as a potential therapy? Clin Exp Ophthalmol 2018; 46:670-686. [PMID: 29205705 DOI: 10.1111/ceo.13121] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 12/11/2022]
Abstract
The retinal pigment epithelium (RPE) comprises a monolayer of cells located between the neuroretina and the choriocapillaries. The RPE serves several important functions in the eye: formation of the blood-retinal barrier, protection of the retina from oxidative stress, nutrient delivery and waste disposal, ionic homeostasis, phagocytosis of photoreceptor outer segments, synthesis and release of growth factors, reisomerization of all-trans-retinal during the visual cycle, and establishment of ocular immune privilege. Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. Dysfunction of the RPE has been associated with the pathogenesis of AMD in relation to increased oxidative stress, mitochondrial destabilization and complement dysregulation. Photobiomodulation or near infrared light therapy which refers to non-invasive irradiation of tissue with light in the far-red to near-infrared light spectrum (630-1000 nm), is an intervention that specifically targets key mechanisms of RPE dysfunction that are implicated in AMD pathogenesis. The current evidence for the efficacy of photobiomodulation in AMD is poor but its safety profile and proposed mechanisms of action motivate further research as a novel therapy for AMD.
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Affiliation(s)
- Jack Ao
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
| | - John Pm Wood
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
| | - Glyn Chidlow
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
| | - Mark C Gillies
- The Save Sight Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Robert J Casson
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
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64
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Kim KL, Park SP. Up-to-date knowledge on age-related macular degeneration. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2018. [DOI: 10.5124/jkma.2018.61.7.416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Kyoung Lae Kim
- Department of Ophthalmology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Sung Pyo Park
- Department of Ophthalmology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
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65
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Ischemic Retinopathies: Oxidative Stress and Inflammation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3940241. [PMID: 29410732 PMCID: PMC5749295 DOI: 10.1155/2017/3940241] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 11/20/2017] [Indexed: 12/15/2022]
Abstract
Ischemic retinopathies (IRs), such as retinopathy of prematurity (ROP), diabetic retinopathy (DR), and (in many cases) age-related macular degeneration (AMD), are ocular disorders characterized by an initial phase of microvascular changes that results in ischemia, followed by a second phase of abnormal neovascularization that may culminate into retinal detachment and blindness. IRs are complex retinal conditions in which several factors play a key role during the development of the different pathological stages of the disease. Increasing evidence reveals that oxidative stress and inflammatory processes are important contributors to the pathogenesis of IRs. Despite the beneficial effects of the photocoagulation and anti-VEGF therapy during neovascularization phase, the need to identify novel targets to prevent initial phases of these ocular pathologies is still needed. In this review, we provide an update on the involvement of oxidative stress and inflammation in the progression of IRs and address some therapeutic interventions by using antioxidants and anti-inflammatory agents.
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66
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Crooke A, Huete-Toral F, Colligris B, Pintor J. The role and therapeutic potential of melatonin in age-related ocular diseases. J Pineal Res 2017; 63. [PMID: 28658514 DOI: 10.1111/jpi.12430] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/23/2017] [Indexed: 12/20/2022]
Abstract
The eye is continuously exposed to solar UV radiation and pollutants, making it prone to oxidative attacks. In fact, oxidative damage is a major cause of age-related ocular diseases including cataract, glaucoma, age-related macular degeneration, and diabetic retinopathy. As the nature of lens cells, trabecular meshwork cells, retinal ganglion cells, retinal pigment epithelial cells, and photoreceptors is postmitotic, autophagy plays a critical role in their cellular homeostasis. In age-related ocular diseases, this process is impaired, and thus, oxidative damage becomes irreversible. Other conditions such as low-grade chronic inflammation and angiogenesis also contribute to the development of retinal diseases (glaucoma, age-related macular degeneration and diabetic retinopathy). As melatonin is known to have remarkable qualities such as antioxidant/antinitridergic, mitochondrial protector, autophagy modulator, anti-inflammatory, and anti-angiogenic, it can represent a powerful tool to counteract all these diseases. The present review analyzes the role and therapeutic potential of melatonin in age-related ocular diseases, focusing on nitro-oxidative stress, autophagy, inflammation, and angiogenesis mechanisms.
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Affiliation(s)
- Almudena Crooke
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Fernando Huete-Toral
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Basilio Colligris
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
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67
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Abstract
Background Visual impairment in elderly people is a considerable health problem that significantly affects quality of life of millions worldwide. The magnitude of this issue is becoming more evident with an aging population and an increasing number of older individuals. Objective The objective of this article was to review the clinical and pathological aspects of age-related macular degeneration (AMD), diagnostic tools, and therapeutic modalities presently available or underway for both atrophic and wet forms of the disease. Methods An online review of the PubMed database was performed, searching for the key words. The search was limited to articles published since 1980 to date. Results Several risk factors have been linked to AMD, such as age (>60 years), lifestyle (smoking and diet), and family history. Although the pathogenesis of AMD remains unclear, genetic factors have been implicated in the condition. Treatment for atrophic AMD is mainly close observation, coupled with nutritional supplements such as zinc and antioxidants, whereas treatment of wet AMD is based on targeting choroidal neovascular membranes. Conclusion Identification of modifiable risk factors would improve the possibilities of preventing the progression of AMD. The role of anti-vascular endothelial growth factor (anti-VEGF) agents has transformed the therapeutic approach of the potentially blinding disease “wet AMD” into a more favorable outcome.
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Affiliation(s)
- Waseem M Al-Zamil
- Department of Ophthalmology, Imam Abdulrahman Bin Faisal University, Al-Khobar, Saudi Arabia
| | - Sanaa A Yassin
- Department of Ophthalmology, Imam Abdulrahman Bin Faisal University, Al-Khobar, Saudi Arabia
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68
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Protective Mechanisms of the Mitochondrial-Derived Peptide Humanin in Oxidative and Endoplasmic Reticulum Stress in RPE Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:1675230. [PMID: 28814984 PMCID: PMC5549471 DOI: 10.1155/2017/1675230] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 06/13/2017] [Accepted: 06/28/2017] [Indexed: 01/02/2023]
Abstract
Age-related macular degeneration (AMD) is the leading cause of severe and irreversible vision loss and is characterized by progressive degeneration of the retina resulting in loss of central vision. The retinal pigment epithelium (RPE) is a critical site of pathology of AMD. Mitochondria and the endoplasmic reticulum which lie in close anatomic proximity to each other are targets of oxidative stress and endoplasmic reticulum (ER) stress, respectively, and contribute to the progression of AMD. The two organelles exhibit close interactive function via various signaling mechanisms. Evidence for ER-mitochondrial crosstalk in RPE under ER stress and signaling pathways of apoptotic cell death is presented. The role of humanin (HN), a prominent member of a newly discovered family of mitochondrial-derived peptides (MDPs) expressed from an open reading frame of mitochondrial 16S rRNA, in modulation of ER and oxidative stress in RPE is discussed. HN protected RPE cells from oxidative and ER stress-induced cell death by upregulation of mitochondrial GSH, inhibition of ROS generation, and caspase 3 and 4 activation. The underlying mechanisms of ER-mitochondrial crosstalk and modulation by exogenous HN are discussed. The therapeutic use of HN and related MDPs could potentially prove to be a valuable approach for treatment of AMD.
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69
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Hongisto H, Jylhä A, Nättinen J, Rieck J, Ilmarinen T, Veréb Z, Aapola U, Beuerman R, Petrovski G, Uusitalo H, Skottman H. Comparative proteomic analysis of human embryonic stem cell-derived and primary human retinal pigment epithelium. Sci Rep 2017; 7:6016. [PMID: 28729539 PMCID: PMC5519552 DOI: 10.1038/s41598-017-06233-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 06/12/2017] [Indexed: 01/28/2023] Open
Abstract
Human embryonic stem cell-derived retinal pigment epithelial cells (hESC-RPE) provide an unlimited cell source for retinal cell replacement therapies. Clinical trials using hESC-RPE to treat diseases such as age-related macular degeneration (AMD) are currently underway. Human ESC-RPE cells have been thoroughly characterized at the gene level but their protein expression profile has not been studied at larger scale. In this study, proteomic analysis was used to compare hESC-RPE cells differentiated from two independent hESC lines, to primary human RPE (hRPE) using Isobaric tags for relative quantitation (iTRAQ). 1041 common proteins were present in both hESC-RPE cells and native hRPE with majority of the proteins similarly regulated. The hESC-RPE proteome reflected that of normal hRPE with a large number of metabolic, mitochondrial, cytoskeletal, and transport proteins expressed. No signs of increased stress, apoptosis, immune response, proliferation, or retinal degeneration related changes were noted in hESC-RPE, while important RPE specific proteins involved in key RPE functions such as visual cycle and phagocytosis, could be detected in the hESC-RPE. Overall, the results indicated that the proteome of the hESC-RPE cells closely resembled that of their native counterparts.
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Affiliation(s)
- Heidi Hongisto
- BioMediTech Institute, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.
| | - Antti Jylhä
- Department of Ophthalmology, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Janika Nättinen
- BioMediTech Institute, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.,Department of Ophthalmology, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Jochen Rieck
- BioMediTech Institute, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Tanja Ilmarinen
- BioMediTech Institute, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Zoltán Veréb
- Stem Cells and Eye Research Laboratory, Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Ulla Aapola
- Department of Ophthalmology, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Roger Beuerman
- Department of Ophthalmology, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.,Singapore Eye Research Institute and Duke-NUS School of Medicine, Singapore, Singapore
| | - Goran Petrovski
- Stem Cells and Eye Research Laboratory, Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary.,Center for Eye Research, Department of Ophthalmology, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Hannu Uusitalo
- Department of Ophthalmology, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.,Tampere University Hospital Eye Center, University of Tampere, Tampere, Finland
| | - Heli Skottman
- BioMediTech Institute, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
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70
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Ferrington DA, Ebeling MC, Kapphahn RJ, Terluk MR, Fisher CR, Polanco JR, Roehrich H, Leary MM, Geng Z, Dutton JR, Montezuma SR. Altered bioenergetics and enhanced resistance to oxidative stress in human retinal pigment epithelial cells from donors with age-related macular degeneration. Redox Biol 2017; 13:255-265. [PMID: 28600982 PMCID: PMC5466586 DOI: 10.1016/j.redox.2017.05.015] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 05/23/2017] [Indexed: 01/03/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness among older adults. It has been suggested that mitochondrial defects in the retinal pigment epithelium (RPE) underlies AMD pathology. To test this idea, we developed primary cultures of RPE to ask whether RPE from donors with AMD differ in their metabolic profile compared with healthy age-matched donors. Analysis of gene expression, protein content, and RPE function showed that these cultured cells replicated many of the cardinal features of RPE in vivo. Using the Seahorse Extracellular Flux Analyzer to measure bioenergetics, we observed RPE from donors with AMD exhibited reduced mitochondrial and glycolytic function compared with healthy donors. RPE from AMD donors were also more resistant to oxidative inactivation of these two energy-producing pathways and were less susceptible to oxidation-induced cell death compared with cells from healthy donors. Investigation of the potential mechanism responsible for differences in bioenergetics and resistance to oxidative stress showed RPE from AMD donors had increased PGC1α protein as well as differential expression of multiple genes in response to an oxidative challenge. Based on our data, we propose that cultured RPE from donors phenotyped for the presence or absence of AMD provides an excellent model system for studying "AMD in a dish". Our results are consistent with the ideas that (i) a bioenergetics crisis in the RPE contributes to AMD pathology, and (ii) the diseased environment in vivo causes changes in the cellular profile that are retained in vitro.
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Affiliation(s)
- Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA,Graduate Program in Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA,Corresponding author at: 380 Lions Research Bldg., 2001 6th St. SE, Minneapolis, MN 55455, USA.
| | - Mara C. Ebeling
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rebecca J. Kapphahn
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Marcia R. Terluk
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Cody R. Fisher
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA,Graduate Program in Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jorge R. Polanco
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Heidi Roehrich
- Histology Core for Vision Research, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Michaela M. Leary
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Zhaohui Geng
- Stem Cell Institute and Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA.
| | - James R. Dutton
- Stem Cell Institute and Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
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71
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Jones MK, Lu B, Girman S, Wang S. Cell-based therapeutic strategies for replacement and preservation in retinal degenerative diseases. Prog Retin Eye Res 2017; 58:1-27. [PMID: 28111323 PMCID: PMC5441967 DOI: 10.1016/j.preteyeres.2017.01.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 01/08/2017] [Accepted: 01/17/2017] [Indexed: 12/13/2022]
Abstract
Cell-based therapeutics offer diverse options for treating retinal degenerative diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). AMD is characterized by both genetic and environmental risks factors, whereas RP is mainly a monogenic disorder. Though treatments exist for some patients with neovascular AMD, a majority of retinal degenerative patients have no effective therapeutics, thus indicating a need for universal therapies to target diverse patient populations. Two main cell-based mechanistic approaches are being tested in clinical trials. Replacement therapies utilize cell-derived retinal pigment epithelial (RPE) cells to supplant lost or defective host RPE cells. These cells are similar in morphology and function to native RPE cells and can potentially supplant the responsibilities of RPE in vivo. Preservation therapies utilize supportive cells to aid in visual function and photoreceptor preservation partially by neurotrophic mechanisms. The goal of preservation strategies is to halt or slow the progression of disease and maintain remaining visual function. A number of clinical trials are testing the safety of replacement and preservation cell therapies in patients; however, measures of efficacy will need to be further evaluated. In addition, a number of prevailing concerns with regards to the immune-related response, longevity, and functionality of the grafted cells will need to be addressed in future trials. This review will summarize the current status of cell-based preclinical and clinical studies with a focus on replacement and preservation strategies and the obstacles that remain regarding these types of treatments.
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Affiliation(s)
- Melissa K Jones
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Bin Lu
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Sergey Girman
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Shaomei Wang
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave., Los Angeles, CA 90095, USA.
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72
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Cehofski LJ, Honoré B, Vorum H. A Review: Proteomics in Retinal Artery Occlusion, Retinal Vein Occlusion, Diabetic Retinopathy and Acquired Macular Disorders. Int J Mol Sci 2017; 18:ijms18050907. [PMID: 28452939 PMCID: PMC5454820 DOI: 10.3390/ijms18050907] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/08/2017] [Accepted: 04/05/2017] [Indexed: 01/26/2023] Open
Abstract
Retinal artery occlusion (RAO), retinal vein occlusion (RVO), diabetic retinopathy (DR) and age-related macular degeneration (AMD) are frequent ocular diseases with potentially sight-threatening outcomes. In the present review we discuss major findings of proteomic studies of RAO, RVO, DR and AMD, including an overview of ocular proteome changes associated with anti-vascular endothelial growth factor (VEGF) treatments. Despite the severe outcomes of RAO, the proteome of the disease remains largely unstudied. There is also limited knowledge about the proteome of RVO, but proteomic studies suggest that RVO is associated with remodeling of the extracellular matrix and adhesion processes. Proteomic studies of DR have resulted in the identification of potential therapeutic targets such as carbonic anhydrase-I. Proliferative diabetic retinopathy is the most intensively studied stage of DR. Proteomic studies have established VEGF, pigment epithelium-derived factor (PEDF) and complement components as key factors associated with AMD. The aim of this review is to highlight the major milestones in proteomics in RAO, RVO, DR and AMD. Through large-scale protein analyses, proteomics is bringing new important insights into these complex pathological conditions.
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Affiliation(s)
- Lasse Jørgensen Cehofski
- Department of Ophthalmology, Aalborg University Hospital, Hobrovej 18-22, 9000 Aalborg, Denmark.
- Department of Clinical Medicine, Aalborg University, Søndre Skovvej 15, 9000 Aalborg, Denmark.
| | - Bent Honoré
- Department of Clinical Medicine, Aalborg University, Søndre Skovvej 15, 9000 Aalborg, Denmark.
- Department of Biomedicine, Aarhus University, Ole Worms Allé 3, Building 1182, 024, 8000 Aarhus C, Denmark.
| | - Henrik Vorum
- Department of Ophthalmology, Aalborg University Hospital, Hobrovej 18-22, 9000 Aalborg, Denmark.
- Department of Clinical Medicine, Aalborg University, Søndre Skovvej 15, 9000 Aalborg, Denmark.
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73
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Mitochondrial dysfunction underlying outer retinal diseases. Mitochondrion 2017; 36:66-76. [PMID: 28365408 DOI: 10.1016/j.mito.2017.03.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 03/06/2017] [Accepted: 03/27/2017] [Indexed: 01/21/2023]
Abstract
Dysfunction of photoreceptors, retinal pigment epithelium (RPE) or both contribute to the initiation and progression of several outer retinal disorders. Disrupted Müller glia function might additionally subsidize to these diseases. Mitochondrial malfunctioning is importantly associated with outer retina pathologies, which can be classified as primary and secondary mitochondrial disorders. This review highlights the importance of oxidative stress and mitochondrial DNA damage, underlying outer retinal disorders. Indeed, the metabolically active photoreceptors/RPE are highly prone to these hallmarks of mitochondrial dysfunction, indicating that mitochondria represent a weak link in the antioxidant defenses of outer retinal cells.
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74
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The impact of oxidative stress and inflammation on RPE degeneration in non-neovascular AMD. Prog Retin Eye Res 2017; 60:201-218. [PMID: 28336424 DOI: 10.1016/j.preteyeres.2017.03.002] [Citation(s) in RCA: 470] [Impact Index Per Article: 67.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly specialized, unique epithelial cell that interacts with photoreceptors on its apical side and with Bruch's membrane and the choriocapillaris on its basal side. Due to vital functions that keep photoreceptors healthy, the RPE is essential for maintaining vision. With aging and the accumulated effects of environmental stresses, the RPE can become dysfunctional and die. This degeneration plays a central role in age-related macular degeneration (AMD) pathobiology, the leading cause of blindness among the elderly in western societies. Oxidative stress and inflammation have both physiological and potentially pathological roles in RPE degeneration. Given the central role of the RPE, this review will focus on the impact of oxidative stress and inflammation on the RPE with AMD pathobiology. Physiological sources of oxidative stress as well as unique sources from photo-oxidative stress, the phagocytosis of photoreceptor outer segments, and modifiable factors such as cigarette smoking and high fat diet ingestion that can convert oxidative stress into a pathological role, and the negative impact of impairing the cytoprotective roles of mitochondrial dynamics and the Nrf2 signaling system on RPE health in AMD will be discussed. Likewise, the response by the innate immune system to an inciting trigger, and the potential role of local RPE production of inflammation, as well as a potential role for damage by inflammation with chronicity if the inciting trigger is not neutralized, will be debated.
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75
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Yacout SM, Gaillard ER. The Anthocyanins, Oenin and Callistephin, Protect RPE Cells Against Oxidative Stress. Photochem Photobiol 2017; 93:590-599. [PMID: 27935050 DOI: 10.1111/php.12683] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/05/2016] [Indexed: 01/07/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly metabolic layer of postmitotic cells lining Bruch's membrane in the retina. While these cells contain endogenous photosensitizers that mediate blue light-induced damage, it has also been shown that blue light exposure damages mitochondrial DNA in RPE cells resulting in mitochondrial dysfunction and unregulated generation of reactive oxygen species (ROS). As RPE cells are postmitotic, it is imperative to decrease oxidative stress to these cells and preserve function. Dietary plant-derived antioxidants such as anthocyanins offer a simple and accessible solution for decreasing oxidative stress. The anthocyanins malvidin-3-O-glucoside (oenin) and pelargonidin-3-O-glucoside (callistephin) were tested for their ability and efficacy in decreasing ROS generation and preserving mitochondrial redox activity in blue light-irradiated ARPE-19 cells. A significant decrease in intracellular ROS with concurrent increase in mitochondrial redox activity was observed for tested concentrations of oenin, while callistephin was beneficial to stressed cells at higher concentrations. These findings suggest anthocyanins are effective antioxidants in blue light-stressed RPE cells in vitro. Additionally, oxidation products of these anthocyanins were examined using LC/MS and findings suggest the possibility of multiple oxidation sites for these compounds.
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Affiliation(s)
- Sally M Yacout
- Department of Chemistry and Biochemistry, Northern Illinois University, Dekalb, IL
| | - Elizabeth R Gaillard
- Department of Chemistry and Biochemistry, Northern Illinois University, Dekalb, IL.,Department of Biological Sciences, Northern Illinois University, Dekalb, IL
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76
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Sripathi SR, Sylvester O, He W, Moser T, Um JY, Lamoke F, Ramakrishna W, Bernstein PS, Bartoli M, Jahng WJ. Prohibitin as the Molecular Binding Switch in the Retinal Pigment Epithelium. Protein J 2016; 35:1-16. [PMID: 26661103 DOI: 10.1007/s10930-015-9641-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Previously, our molecular binding study showed that prohibitin interacts with phospholipids, including phosphatidylinositide and cardiolipin. Under stress conditions, prohibitin interacts with cardiolipin as a retrograde response to activate mitochondrial proliferation. The lipid-binding switch mechanism of prohibitin with phosphatidylinositol-3,4,5-triphosphate and cardiolipin may suggest the role of prohibitin effects on energy metabolism and age-related diseases. The current study examined the region-specific expressions of prohibitin with respect to the retina and retinal pigment epithelium (RPE) in age-related macular degeneration (AMD). A detailed understanding of prohibitin binding with lipids, nucleotides, and proteins shown in the current study may suggest how molecular interactions control apoptosis and how we can intervene against the apoptotic pathway in AMD. Our data imply that decreased prohibitin in the peripheral RPE is a significant step leading to mitochondrial dysfunction that may promote AMD progression.
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Affiliation(s)
- Srinivas R Sripathi
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA.,Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - O'Donnell Sylvester
- Retina Proteomics Laboratory, Department of Petroleum Chemistry, American University of Nigeria, Yola, Nigeria
| | - Weilue He
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA
| | - Trevor Moser
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA
| | - Ji-Yeon Um
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA
| | - Folami Lamoke
- Department of Ophthalmology, Georgia Regents University, Augusta, GA, 30912, USA
| | - Wusirika Ramakrishna
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA
| | - Paul S Bernstein
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA
| | - Manuela Bartoli
- Department of Ophthalmology, Georgia Regents University, Augusta, GA, 30912, USA
| | - Wan Jin Jahng
- Retina Proteomics Laboratory, Department of Petroleum Chemistry, American University of Nigeria, Yola, Nigeria.
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77
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Chong CM, Zheng W. Artemisinin protects human retinal pigment epithelial cells from hydrogen peroxide-induced oxidative damage through activation of ERK/CREB signaling. Redox Biol 2016; 9:50-56. [PMID: 27372058 PMCID: PMC4939375 DOI: 10.1016/j.redox.2016.06.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 02/07/2023] Open
Abstract
The pathological increase in the levels of reactive oxygen species (ROS) in the retinal pigment epithelium (RPE), is implicated in the development of age-related macular degeneration (AMD). The discovery of drug candidates to effectively protect RPE cells from oxidative damage is required to resolve the pathological aspects and modify the process of AMD. In this study, a FDA-approved anti-malaria drug, Artemisinin was found to suppress hydrogen peroxide (H2O2)-induced cell death in human RPE cell-D407 cells. Further study showed that Artemisinin significantly suppressed H2O2- induced D407 cell death by restoring abnormal changes in nuclear morphology, intracellular ROS, mitochondrial membrane potential and apoptotic biomarkers. Western blotting analysis showed that Artemisinin was able to activate extracellular regulated ERK/CREB survival signaling. Furthermore, Artemisinin failed to suppress H2O2-induced cytotoxicity and the increase of caspase 3/7 activity in the presence of the ERK inhibitor PD98059. Taken together, these results suggest that Artemisinin is a potential protectant with the pro-survival effects against H2O2 insult through activation of the ERK/CREB pathway.
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Affiliation(s)
| | - Wenhua Zheng
- Faculty of Health Science, University of Macau, Macau, China.
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78
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Perspectives on reticular pseudodrusen in age-related macular degeneration. Surv Ophthalmol 2016; 61:521-37. [DOI: 10.1016/j.survophthal.2016.02.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/22/2016] [Accepted: 02/26/2016] [Indexed: 11/20/2022]
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79
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Gouras P, Ivert L, Neuringer M, Nagasaki T. Mitochondrial elongation in the macular RPE of aging monkeys, evidence of metabolic stress. Graefes Arch Clin Exp Ophthalmol 2016; 254:1221-7. [PMID: 27106622 DOI: 10.1007/s00417-016-3342-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 03/29/2016] [Accepted: 04/04/2016] [Indexed: 12/11/2022] Open
Abstract
PURPOSE This study was conducted to determine whether mitochondria of the macular retinal pigment epithelium (RPE) change with age in rhesus monkeys (Macaca mulatta). Mitochondria are the main instigators of oxidative stress, which has often been considered to play a role in the pathogenesis of age-related macular degeneration (AMD). Any pathological changes in the mitochondria of aging macular RPE, the main target of AMD, would be a clue to the pathogenesis of this common retinal degeneration afflicting both monkey and man. METHODS Transmission electron microscopy was used to identify mitochondria and to determine their appearance, their density per unit area of RPE cytoplasm and their length. The eyes of seven monkeys, 1, 2, 6.5, 23, 26, 27 and 35 years of age, were studied. Measurements were kept separate for the basal, middle and apical third of each cell. The basal third of the macular RPE had many more mitochondria than the middle third, and the apical third was almost devoid of mitochondria. RESULTS Mitochondrial number decreased and length increased with age. The increase in length was associated with an unusual clustering of mitochondria into parallel arrays of elongated mitochondria, with their long axis orthogonal to the basal membrane of the cell, structures not described before in RPE. CONCLUSIONS Mitochondrial elongation is associated with metabolic and/or oxidative stress, which implies that age produces stress in macular RPE. The increased clustering of very elongated mitochondria suggests that pathological changes occur in mitochondrial organization with age. These changes support the hypothesis that age-related mitochondrial dysfunction plays a role in the pathogenesis of AMD.
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Affiliation(s)
- Peter Gouras
- Department of Ophthalmology, Columbia University, New York City, NY, USA. .,Edward S. Harkness Eye Institute, Research Annex, 635 West 165th Street, Box #76, New York, NY, 10032, USA.
| | - L Ivert
- St. Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden
| | - M Neuringer
- Oregon Health & Science University, Portland, OR, USA
| | - T Nagasaki
- Department of Ophthalmology, Columbia University, New York City, NY, USA
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Oxidative Stress and the Nrf2 Anti-Oxidant Transcription Factor in Age-Related Macular Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:67-72. [PMID: 26427395 DOI: 10.1007/978-3-319-17121-0_10] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of acquired and irreversible blindness among elderly Americans. Most AMD patients have the dry form of the disease (dAMD) for which reliable therapies are lacking. A major obstacle to the development of effective treatments is a deficit in our understanding of what triggers dAMD onset. This is particularly the case with respect to the events that cause retinal pigment epithelial (RPE) cells to transition from a state of health and homeostasis to one of dysfunction and atrophy. These cells provide critical support to the photoreceptors and their atrophy often precipitates photoreceptor death in dAMD. Chronic oxidative stress is a primary driver of age-dependent, RPE atrophy. Sources of this stress have been identified (e.g., cigarette smoke, photooxidized bisretinoids), but we still do not understand how these stressors damage RPE constituents or what age-dependent changes undermine the cytoprotective systems in the RPE. This review focuses on Nrf2, the master antioxidant transcription factor, and its role in the RPE during aging and dAMD onset.
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81
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Ferrington DA, Kapphahn RJ, Leary MM, Atilano SR, Terluk MR, Karunadharma P, Chen GKJ, Ratnapriya R, Swaroop A, Montezuma SR, Kenney MC. Increased retinal mtDNA damage in the CFH variant associated with age-related macular degeneration. Exp Eye Res 2016; 145:269-277. [PMID: 26854823 DOI: 10.1016/j.exer.2016.01.018] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/25/2016] [Accepted: 01/29/2016] [Indexed: 11/17/2022]
Abstract
Age-related macular degeneration (AMD) is a major cause of blindness among the elderly in the developed world. Genetic analysis of AMD has identified 34 high-risk loci associated with AMD. The genes at these high risk loci belong to diverse biological pathways, suggesting different mechanisms leading to AMD pathogenesis. Thus, therapies targeting a single pathway for all AMD patients will likely not be universally effective. Recent evidence suggests defects in mitochondria (mt) of the retinal pigment epithelium (RPE) may constitute a key pathogenic event in some AMD patients. The purpose of this study is to determine if individuals with a specific genetic background have a greater propensity for mtDNA damage. We used human eyebank tissues from 76 donors with AMD and 42 age-matched controls to determine the extent of mtDNA damage in the RPE that was harvested from the macula using a long extension polymerase chain reaction assay. Genotype analyses were performed for ten common AMD-associated nuclear risk alleles (ARMS2, TNFRSF10A, CFH, C2, C3, APOE, CETP, LIPC, VEGF and COL10A1) and mtDNA haplogroups. Sufficient samples were available for genotype association with mtDNA damage for TNFRSF10A, CFH, CETP, VEGFA, and COL10A1. Our results show that AMD donors carrying the high risk allele for CFH (C) had significantly more mtDNA damage compared with donors having the wild-type genetic profile. The data from an additional 39 donors (12 controls and 27 AMD) genotyped for CFH alleles further supported these findings. Taken together, these studies provide the rationale for a more personalized approach for treating AMD by uncovering a significant correlation between the CFH high risk allele and accelerated mtDNA damage. Patients harboring this genetic risk factor may benefit from therapies that stabilize and protect the mt in the RPE.
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Affiliation(s)
- Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA.
| | - Rebecca J Kapphahn
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Michaela M Leary
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Shari R Atilano
- Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA
| | - Marcia R Terluk
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Pabalu Karunadharma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | | | - Rinki Ratnapriya
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, Bethesda, MD 20892, USA
| | - Sandra R Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | - M Cristina Kenney
- Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA
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82
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Nita M, Grzybowski A. The Role of the Reactive Oxygen Species and Oxidative Stress in the Pathomechanism of the Age-Related Ocular Diseases and Other Pathologies of the Anterior and Posterior Eye Segments in Adults. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3164734. [PMID: 26881021 PMCID: PMC4736974 DOI: 10.1155/2016/3164734] [Citation(s) in RCA: 808] [Impact Index Per Article: 101.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 12/18/2022]
Abstract
The reactive oxygen species (ROS) form under normal physiological conditions and may have both beneficial and harmful role. We search the literature and current knowledge in the aspect of ROS participation in the pathogenesis of anterior and posterior eye segment diseases in adults. ROS take part in the pathogenesis of keratoconus, Fuchs endothelial corneal dystrophy, and granular corneal dystrophy type 2, stimulating apoptosis of corneal cells. ROS play a role in the pathogenesis of glaucoma stimulating apoptotic and inflammatory pathways on the level of the trabecular meshwork and promoting retinal ganglion cells apoptosis and glial dysfunction in the posterior eye segment. ROS play a role in the pathogenesis of Leber's hereditary optic neuropathy and traumatic optic neuropathy. ROS induce apoptosis of human lens epithelial cells. ROS promote apoptosis of vascular and neuronal cells and stimulate inflammation and pathological angiogenesis in the course of diabetic retinopathy. ROS are associated with the pathophysiological parainflammation and autophagy process in the course of the age-related macular degeneration.
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Affiliation(s)
- Małgorzata Nita
- Domestic and Specialized Medicine Centre “Dilmed”, Ulica Bohaterów Monte Cassino 3, 40-231 Katowice, Poland
| | - Andrzej Grzybowski
- Department of Ophthalmology, Poznan City Hospital, Ulica Szwajcarska 3, 61-285 Poznań, Poland
- Chair of Ophthalmology, Medical Faculty, University of Warmia and Mazury, Ulica Żołnierska 14 C, 10-719 Olsztyn, Poland
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83
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Ferrington DA, Sinha D, Kaarniranta K. Defects in retinal pigment epithelial cell proteolysis and the pathology associated with age-related macular degeneration. Prog Retin Eye Res 2015; 51:69-89. [PMID: 26344735 DOI: 10.1016/j.preteyeres.2015.09.002] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 08/29/2015] [Accepted: 09/01/2015] [Indexed: 12/12/2022]
Abstract
Maintenance of protein homeostasis, also referred to as "Proteostasis", integrates multiple pathways that regulate protein synthesis, folding, translocation, and degradation. Failure in proteostasis may be one of the underlying mechanisms responsible for the cascade of events leading to age-related macular degeneration (AMD). This review covers the major degradative pathways (ubiquitin-proteasome and lysosomal involvement in phagocytosis and autophagy) in the retinal pigment epithelium (RPE) and summarizes evidence of their involvement in AMD. Degradation of damaged and misfolded proteins via the proteasome occurs in coordination with heat shock proteins. Evidence of increased content of proteasome and heat shock proteins in retinas from human donors with AMD is consistent with increased oxidative stress and extensive protein damage with AMD. Phagocytosis and autophagy share key molecules in phagosome maturation as well as degradation of their cargo following fusion with lysosomes. Phagocytosis and degradation of photoreceptor outer segments ensures functional integrity of the neural retina. Autophagy rids the cell of toxic protein aggregates and defective mitochondria. Evidence suggesting a decline in autophagic flux includes the accumulation of autophagic substrates and damaged mitochondria in RPE from AMD donors. An age-related decrease in lysosomal enzymatic activity inhibits autophagic clearance of outer segments, mitochondria, and protein aggregates, thereby accelerating the accumulation of lipofuscin. This cumulative damage over a person's lifetime tips the balance in RPE from a state of para-inflammation, which strives to restore cell homeostasis, to the chronic inflammation associated with AMD.
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Affiliation(s)
- Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, 2001 6th St SE, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Debasish Sinha
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Room M035 Robert and Clarice Smith Bldg, 400 N Broadway, Baltimore, MD, 21287, USA.
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland and Kuopio University Hospital, P.O. Box 100, 70029 KYS, Finland.
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84
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Olsen TW, Bottini AR, Mendoza P, Grossniklausk HE. The Age-Related Macular Degeneration Complex: Linking Epidemiology and Histopathology Using the Minnesota Grading System (The Inaugural Frederick C. Blodi Lecture). TRANSACTIONS OF THE AMERICAN OPHTHALMOLOGICAL SOCIETY 2015; 113:Blodi. [PMID: 27895380 PMCID: PMC5108344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
PURPOSE To describe the histopathologic findings of the four stages of age-related macular degeneration (AMD) as defined by the Age-Related Eye Disease Study (AREDS) using the Minnesota grading system (MGS). CLINICAL RELEVANCE There are no animal models for AMD. Eye banks enable access to human tissue with AMD. The level of AMD (grades 1 through 4) as defined by AREDS is determined ex vivo using the MGS. The AREDS has the largest collection to date of prospectively gathered data on the natural history of AMD. Since the MGS uses the same clinical criteria as AREDS, the addition of histopathologic findings of graded tissue confirms important pathophysiology at each stage of AMD. METHODS Four eye bank eyes were graded according to the MGS. Only the right eyes were dissected for phenotype grading. The fellow (left) eyes were fixed for histopathologic study. The eyes were serially sectioned (7 μm) through the macula. Individual slides were examined, and a two-dimensional reconstruction of the topography of the macula was created for each donor. Selected, unstained slides were used for immunohistochemical staining. In one donor, portions of tissue were obtained for transmission electron microscopic (TEM) processing. RESULTS Donor 1 had a rare hard, nodular druse (MGS1). Donor 2 had intermediate confluent drusen (MGS2). Donor 3 had numerous intermediate drusen (MGS3) in the right eye. Histopathology of the fellow left showed basal laminar deposits (BLamD), soft drusen, and an area of occult choroidal neovascularization underlying the retinal pigment epithelium (RPE) with endothelial cells (CD31-positive). Donor 4 also had MGS 3 along with reticular pseudodrusen (RPD). Histologic and TEM examination demonstrated diffuse BLamD, thickening of Bruch's membrane, hard drusen, and focal nodules underlying the RPE that corresponded to the RPD. EM examination demonstrated both BLamD and electron-dense material located just external to the elastic layer of Bruch's membrane. CONCLUSION Eye bank eyes graded using the MGS serve as an important link to the phenotypic and epidemiologic data from the AREDS. Thus, the MGS serves as a system to study the histopathology at each stage of AMD to better understand the relevant pathophysiologic changes in disease progression.
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Affiliation(s)
- Timothy W Olsen
- Emory Eye Center, Emory University Department of Ophthalmology, Atlanta, Georgia. Presented as the Inaugural Frederick C. Blodi Lecture at the 151st American Ophthalmological Society meeting, May 16, 2015, Newport, Rhode Island
| | - Alexander R Bottini
- Emory Eye Center, Emory University Department of Ophthalmology, Atlanta, Georgia. Presented as the Inaugural Frederick C. Blodi Lecture at the 151st American Ophthalmological Society meeting, May 16, 2015, Newport, Rhode Island
| | - Pia Mendoza
- Emory Eye Center, Emory University Department of Ophthalmology, Atlanta, Georgia. Presented as the Inaugural Frederick C. Blodi Lecture at the 151st American Ophthalmological Society meeting, May 16, 2015, Newport, Rhode Island
| | - Hans E Grossniklausk
- Emory Eye Center, Emory University Department of Ophthalmology, Atlanta, Georgia. Presented as the Inaugural Frederick C. Blodi Lecture at the 151st American Ophthalmological Society meeting, May 16, 2015, Newport, Rhode Island
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85
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Georgiannakis A, Burgoyne T, Lueck K, Futter C, Greenwood J, Moss SE. Retinal Pigment Epithelial Cells Mitigate the Effects of Complement Attack by Endocytosis of C5b-9. THE JOURNAL OF IMMUNOLOGY 2015; 195:3382-9. [PMID: 26324770 PMCID: PMC4574521 DOI: 10.4049/jimmunol.1500937] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/29/2015] [Indexed: 01/01/2023]
Abstract
Retinal pigment epithelial (RPE) cell death is a hallmark of age-related macular degeneration. The alternative pathway of complement activation is strongly implicated in RPE cell dysfunction and loss in age-related macular degeneration; therefore, it is critical that RPE cells use molecular strategies to mitigate the potentially harmful effects of complement attack. We show that the terminal complement complex C5b-9 assembles rapidly on the basal surface of cultured primary porcine RPE cells but disappears over 48 h without any discernable adverse effects on the cells. However, in the presence of the dynamin inhibitor dynasore, C5b-9 was almost completely retained at the cell surface, suggesting that, under normal circumstances, it is eliminated via the endocytic pathway. In support of this idea, we observed that C5b-9 colocalizes with the early endosome marker EEA1 and that, in the presence of protease inhibitors, it can be detected in lysosomes. Preventing the endocytosis of C5b-9 by RPE cells led to structural defects in mitochondrial morphology consistent with cell stress. We conclude that RPE cells use the endocytic pathway to prevent the accumulation of C5b-9 on the cell surface and that processing and destruction of C5b-9 by this route are essential for RPE cell survival.
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Affiliation(s)
- Apostolos Georgiannakis
- Department of Cell Biology, University College London Institute of Ophthalmology, London EC1V9EL, United Kingdom
| | - Tom Burgoyne
- Department of Cell Biology, University College London Institute of Ophthalmology, London EC1V9EL, United Kingdom
| | - Katharina Lueck
- Department of Cell Biology, University College London Institute of Ophthalmology, London EC1V9EL, United Kingdom
| | - Clare Futter
- Department of Cell Biology, University College London Institute of Ophthalmology, London EC1V9EL, United Kingdom
| | - John Greenwood
- Department of Cell Biology, University College London Institute of Ophthalmology, London EC1V9EL, United Kingdom
| | - Stephen E Moss
- Department of Cell Biology, University College London Institute of Ophthalmology, London EC1V9EL, United Kingdom
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Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness among older adults in the developed world. Although the pathological mechanisms have not been definitively elucidated, evidence suggests a key role for mitochondrial (mt) dysfunction. The current study used our unique collection of human retinal samples graded for the donor's stage of AMD to address fundamental questions about mtDNA damage in the retina. To evaluate the distribution of mtDNA damage in the diseased retina, damage in the retinal pigment epithelium (RPE) and neural retina from individual donors were compared. To directly test a long-held belief that the macula is selectively damaged with AMD, RPE mtDNA damage was measured in the macula and peripheral sections from individual donors. Small segments of the entire mt genome were examined to determine whether specific regions are preferentially damaged. Our results show that mtDNA damage is limited to the RPE, equivalent mtDNA damage is found in the macular and peripheral RPE, and sites of damage are localized to regions of the mt genome that may impact mt function. These results provide a scientific basis for targeting the RPE mitochondria with therapies that protect and enhance mt function as a strategy for combating AMD.
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87
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Calaza KC, Kam JH, Hogg C, Jeffery G. Mitochondrial decline precedes phenotype development in the complement factor H mouse model of retinal degeneration but can be corrected by near infrared light. Neurobiol Aging 2015; 36:2869-76. [PMID: 26149919 DOI: 10.1016/j.neurobiolaging.2015.06.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 06/02/2015] [Accepted: 06/05/2015] [Indexed: 11/18/2022]
Abstract
Mitochondria produce adenosine triphosphate (ATP), critical for cellular metabolism. ATP declines with age, which is associated with inflammation. Here, we measure retinal and brain ATP in normal C57BL/6 and complement factor H knockout mice (Cfh(-/-)), which are proposed as a model of age-related macular degeneration. We show a significant premature 30% decline in retinal ATP in Cfh(-/-) mice and a subsequent shift in expression of a heat shock protein that is predominantly mitochondrial (Hsp60). Changes in Hsp60 are associated with stress and neuroprotection. We find no differences in brain ATP between C57BL/6 and Cfh(-/-) mice. Near infrared (NIR) increases ATP and reduces inflammation. ATP decline in Cfh(-/-) mice was corrected with NIR which also shifted Hsp60 labeling patterns. ATP decline in Cfh(-/-) mice occurs before inflammation becomes established and photoreceptor loss occurs and may relate to disease etiology. However, ATP levels were corrected with NIR. In summary, we provide evidence for a mitochondrial basis for this disease in mice and correct this with simple light exposure known to improve mitochondrial function.
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Affiliation(s)
- Karin C Calaza
- Program of Neurosciences, Institute of Biology, Federal Fluminense University, Rio de Janeiro, Brazil; Institute of Ophthalmology University College London, London, UK
| | - Jaimie Hoh Kam
- Institute of Ophthalmology University College London, London, UK
| | | | - Glen Jeffery
- Institute of Ophthalmology University College London, London, UK.
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88
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Chiras D, Kitsos G, Petersen MB, Skalidakis I, Kroupis C. Oxidative stress in dry age-related macular degeneration and exfoliation syndrome. Crit Rev Clin Lab Sci 2014; 52:12-27. [PMID: 25319011 DOI: 10.3109/10408363.2014.968703] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Oxidative stress refers to cellular or molecular damage caused by reactive oxygen species, which especially occurs in age-related conditions as a result of an imbalance between the production of reactive oxygen species and the antioxidant defense response. Dry age-related macular degeneration (AMD) and exfoliation syndrome (XFS) are two common and complex age-related conditions that can cause irreversible vision loss. Two subtypes of AMD, which is the leading cause of blindness in the Western world, exist: the most prevalent dry type and the most severe wet type. Early dry AMD is characterized by formation of drusen, which are sub-retinal deposits, in the macular area and may progress to geographic atrophy with more dramatic manifestation. XFS is a systemic disorder of the extracellular matrix characterized by the accumulation of elastic fibrils that leads, in most cases, to glaucoma development with progressive and irreversible vision loss. Due to the aging population, the prevalence of these already-widespread conditions is increasing and is resulting in significant economic and psychological costs for individuals and for society. The exact composition of the abnormal drusen and XFS material as well as the mechanisms responsible for their production and accumulation still remain elusive, and consequently treatment for both diseases is lacking. However, recent epidemiologic, genetic and molecular studies support a major role for oxidative stress in both dry AMD and XFS development. Understanding the early molecular events in their pathogenesis and the exact role of oxidative stress may provide novel opportunities for therapeutic intervention for the prevention of progression to advanced disease.
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Affiliation(s)
- Dimitrios Chiras
- Department of Ophthalmology, University Hospital of Ioannina , Ioannina , Greece
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89
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Subrizi A, Toropainen E, Ramsay E, Airaksinen AJ, Kaarniranta K, Urtti A. Oxidative stress protection by exogenous delivery of rhHsp70 chaperone to the retinal pigment epithelium (RPE), a possible therapeutic strategy against RPE degeneration. Pharm Res 2014; 32:211-21. [PMID: 25030185 DOI: 10.1007/s11095-014-1456-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 07/02/2014] [Indexed: 11/30/2022]
Abstract
PURPOSE To measure the cytoprotective effects of rhHsp70 against oxidative stress and study its cellular uptake, intracellular and intraocular distribution in the retinal pigment epithelium. METHODS Human retinal pigment epithelial cells (ARPE-19) were pre-treated with rhHsp70 for 24 h, 48 h, and 72 h before being exposed to 1.25 mM hydrogen peroxide. Non-treated cells served as control. We analysed interleukin 6 secretion, cell viability, and cytolysis. Uptake and intracellular distribution of fluorescently labelled rhHsp70 were investigated with flow cytometry and confocal microscopy, respectively. Ocular distribution of radioactively labelled rhHsp70 was followed ex vivo in porcine eyes by micro SPECT/CT. RESULTS After exposure to hydrogen peroxide, IL-6 secretion decreased by 35-39% when ARPE-19 cells were pre-treated with rhHsp70. Cell viability increased by 17-32%, and cell lysis, measured by the release of lactate dehydrogenase, decreased by 6-43%. ARPE-19 cells endocytosed rhHsp70 added to the culture medium and the protein was localized in late endosomes and lysosomes. Following intravitreal injection into isolated porcine eyes, we found 20% rhHsp70 in the RPE. CONCLUSIONS Recombinant hHsp70 protein offers protection against oxidative stress. RPE cells take up the exogenously delivered rhHsp70 and localize it in late endosomes and lysosomes. This work provides the basis for a therapeutic strategy to target aggregate-associated neurodegeneration in AMD.
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Affiliation(s)
- Astrid Subrizi
- Centre for Drug Research, Division of Pharmaceutical Biosciences Faculty of Pharmacy, University of Helsinki, Helsinki, Finland,
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90
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Mao H, Seo SJ, Biswal MR, Li H, Conners M, Nandyala A, Jones K, Le YZ, Lewin AS. Mitochondrial oxidative stress in the retinal pigment epithelium leads to localized retinal degeneration. Invest Ophthalmol Vis Sci 2014; 55:4613-27. [PMID: 24985474 DOI: 10.1167/iovs.14-14633] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PURPOSE Oxidative stress in the RPE is widely accepted as a contributing factor to AMD. We have previously shown that ribozyme-mediated reduction in the antioxidant enzyme manganese superoxide dismutase (MnSOD) leads to some of the features of geographic atrophy in mice. To develop a mouse model independent of viral injection, we used a conditional knockout of the Sod2 gene in the RPE to elevate mitochondrial oxidative stress in that cell layer. METHODS Experimental mice in which exon 3 of Sod2 was flanked by loxP sites were also transgenic for PVMD2-rtTA and tetO-PhCMV cre, so that cre recombinase was expressed only in the RPE. Pups of this genotype (Sod2(flox/flox)VMD2cre) were induced to express cre recombinase by feeding doxycycline-laced chow to nursing dams. Controls included mice of this genotype not treated with doxycycline and doxycycline-treated Sod2(flox/flox) mice lacking the cre transgene. Expression of cre in the RPE was verified by immunohistochemistry, and deletion of Sod2 exon 3 in the RPE was confirmed by PCR. Mice were followed up over a period of 9 months by spectral-domain optical coherence tomography (SD-OCT), digital fundus imaging, and full-field ERG. Following euthanasia, retinas were examined by light and electron microscopy or by immunohistochemistry. Contour length of rod outer segments and thickness of the RPE layer were measured by unbiased stereology. RESULTS Following doxycycline induction of cre, Sod2(flox/flox) cre mice demonstrated increased signs of oxidative stress in the RPE and accumulation of autofluorescent material by age 2 months. They showed a gradual decline in the ERG response and thinning of the outer nuclear layer (by SD-OCT), which were statistically significant by 6 months. In addition, OCT and electron microscopy revealed increased porosity of the choroid. At the same interval, hypopigmented foci appeared in fundus micrographs, and vascular abnormalities were detected by fluorescein angiography. By 9 months, the RPE layer in Sod2(flox/flox) cre mice was thicker than in nontransgenic littermates, and the rod outer segments were significantly longer over most of the retina, although localized atrophy of photoreceptors was also obvious in some eyes. CONCLUSIONS Conditional tissue-specific reduction in MnSOD induced oxidative stress in mouse RPE, leading to RPE dysfunction, damage to the choroid, and death of photoreceptor cells. The RPE oxidative stress did not cause drusen-like deposits, but the model recapitulated certain key aspects of the pathology of dry AMD and may be useful in testing therapies.
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Affiliation(s)
- Haoyu Mao
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Soo Jung Seo
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Manas R Biswal
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Hong Li
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Mandy Conners
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Arathi Nandyala
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Kyle Jones
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Yun-Zheng Le
- Departments of Medicine, Endocrinology, and Cell Biology and Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States
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91
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Aging leads to elevation of O-GlcNAcylation and disruption of mitochondrial homeostasis in retina. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:425705. [PMID: 24987494 PMCID: PMC4060167 DOI: 10.1155/2014/425705] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/09/2014] [Indexed: 12/21/2022]
Abstract
Retina is particularly susceptible to aging as oxidative damage accumulates within retina, leading to age-related retinal dysfunction or even visual loss. However, the underlying mechanisms still remain obscure and effective therapeutic strategy is urgently in need. Here, we quested for the answer particularly focusing on mitochondrial homeostasis and O-GlcNAcylation in rat retina. By comparing expression of electron transfer chain complexes and key factors in mitochondrial biogenesis and dynamics in retinas of aged and young Sprague-Dawley rats, we found that mitochondrial Complex I, II, IV and V were increased in aged retina with decreased mtTFA and Mfn2. Also, we noticed that p38 and JNK of MAPK signaling were substantially more activated in aged retina, suggesting stress induction. In addition, we found that pan-O-GlcNAcylation was remarkably stronger with lower OGA expression in aged retina. To further elucidate the roles of Mfn2 and O-GlcNAcylation, we employed ARPE-19 cells and found that ATP production, oxygen consumption, and mitochondrial membrane potential were reduced and ROS level was increased by Mfn2 knockdown, while treating with PUGNAc or UDP-GlcNAc heightened oxygen consumption and reduced ROS. Our results suggest disrupted mitochondrial homeostasis may increase oxidative stress; yet enhanced O-GlcNAcylation might defend against oxidative stress and promote mitochondrial respiration in aged retina.
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Abstract
The formation of extracellular deposits known as drusen below the macular region of the retina correlates with increased risk of severe visual loss from age-related macular degeneration (AMD). Inflammation and complement dysregulation contribute to AMD progression; however, disease mechanisms remain incompletely defined. Multiple genetic and environmental factors influence AMD pathology, and although immune system processes play a central role, multiple molecular mechanisms appear to be involved. Drusen proteomics, including the analyses of constituent proteins, oxidative protein modifications, and pattern recognition receptors, provide a foundation for deciphering mechanisms of drusen biogenesis and AMD pathology.
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Affiliation(s)
- John W Crabb
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
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93
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Xu XR, Zhong L, Huang BL, Wei YH, Zhou X, Wang L, Wang FQ. Comparative proteomic analysis of plasma proteins in patients with age-related macular degeneration. Int J Ophthalmol 2014; 7:256-63. [PMID: 24790867 DOI: 10.3980/j.issn.2222-3959.2014.02.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 12/18/2013] [Indexed: 09/26/2022] Open
Abstract
AIM To find the significant altered proteins in age-related macular degeneration (AMD) patients as potential biomarkers of AMD. METHODS A comparative analysis of the protein pattern of AMD patients versus healthy controls was performed by means of proteomic analysis using two-dimensional gel electrophoresis followed by protein identification with MALDI TOF/TOF mass spectrometry. RESULTS We identified 28 proteins that were significantly altered with clinical relevance in AMD patients. These proteins were involved in a wide range of biological functions including immune responses, growth cytokines, cell fate determination, wound healing, metabolism, and anti-oxidance. CONCLUSION These results demonstrate the capacity of proteomic analysis of AMD patient plasma. In addition to the utility of this approach for biomarker discovery, identification of alterations in endogenous proteins in the plasma of AMD patient could improve our understanding of the disease pathogenesis.
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Affiliation(s)
- Xin-Rong Xu
- Department of Ophthalmology, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing 210029, Jiangsu Province, China
| | - Lu Zhong
- Department of Ophthalmology, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing 210029, Jiangsu Province, China
| | - Bing-Lin Huang
- Department of Ophthalmology, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing 210029, Jiangsu Province, China
| | - Yuan-Hua Wei
- Department of Clinical Laboratory, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing 210029, Jiangsu Province, China
| | - Xin Zhou
- Department of Ophthalmology, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing 210029, Jiangsu Province, China
| | - Ling Wang
- Analytical Instrumentation Center, Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
| | - Fu-Qiang Wang
- Analytical Instrumentation Center, Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
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94
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Zhou YY, Chen CZ, Su Y, Li L, Yi ZHZ, Qi H, Weng M, Xing YQ. Effect of EGb761 on light-damaged retinal pigment epithelial cells. Int J Ophthalmol 2014; 7:8-13. [PMID: 24644534 DOI: 10.3980/j.issn.2222-3959.2014.01.02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Accepted: 09/26/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate the protective mechanism of Gingko Biloba extract (EGb761) on the ability of retinal pigment epithelial (RPE) cells to resist light-induced damage in a comparative proteomics study. METHODS Human RPE cells (ARPE-19) were randomly distributed to one of three groups: normal control (NC group) and light-damaged model without or with EGb761 group (M and ME groups, respectively). The light-damaged model was formed by exposing to white light (2 200±300)lx for 6h. The RPE cells in ME group were conducted with EGb 761 (100µg/mL) before light exposure. The soluble cellular proteins extracting from each groups were separated by two-dimensional electrophoresis and stained by silver staining. Different proteins in the profiles of the gels were analyzed by Image Master Software. Two-fold expressing protein spots were identified by Matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry. RESULTS NC, M and ME groups displayed 1 892±71, 2 145±23 and 2 216±85 protein spots, respectively. We identified 33 proteins with different expression levels between the NC and M groups, 25 proteins between the M and ME groups, and 11 proteins between the NC and ME groups. MALDI-TOF/TOF mass spectrometry successfully identified 16 proteins, including metabolic enzymes, cytoskeletal proteins, anti-oxidation proteins, and others. CONCLUSION Differences in some important proteins, such as cathepsin B, heat shock protein, and cytochrome c reductase, indicated that multiple pathways may be induced in light-damaged RPE cells and the protective effect of EGb761.
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Affiliation(s)
- Yun-Yun Zhou
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Chang-Zheng Chen
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Yu Su
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China
| | - Lu Li
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Zuo-Hui-Zi Yi
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Hang Qi
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Ming Weng
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
| | - Yi-Qiao Xing
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China
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95
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Gene therapy for mitochondrial diseases: Leber Hereditary Optic Neuropathy as the first candidate for a clinical trial. C R Biol 2014; 337:193-206. [PMID: 24702846 DOI: 10.1016/j.crvi.2013.11.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 11/28/2013] [Indexed: 12/30/2022]
Abstract
Mitochondrial disorders cannot be ignored anymore in most medical disciplines; indeed their minimum estimated prevalence is superior to 1 in 5000 births. Despite the progress made in the last 25 years on the identification of gene mutations causing mitochondrial pathologies, only slow progress was made towards their effective treatments. Ocular involvement is a frequent feature in mitochondrial diseases and corresponds to severe and irreversible visual handicap due to retinal neuron loss and optic atrophy. Interestingly, three clinical trials for Leber Congenital Amaurosis due to RPE65 mutations are ongoing since 2007. Overall, the feasibility and safety of ocular Adeno-Associated Virus delivery in adult and younger patients and consistent visual function improvements have been demonstrated. The success of gene-replacement therapy for RPE65 opens the way for the development of similar approaches for a broad range of eye disorders, including those with mitochondrial etiology such as Leber Hereditary Optic Neuropathy (LHON).
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96
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Feng CY, Huang XR, Qi MX, Tang SW, Chen S, Hu YH, Ke FJ, Wang X. Mitochondrial proteomic analysis of ecdysterone protection against oxidative damage in human lens epithelial cells. Int J Ophthalmol 2014; 7:38-43. [PMID: 24634861 DOI: 10.3980/j.issn.2222-3959.2014.01.07] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 10/12/2012] [Indexed: 01/28/2023] Open
Abstract
AIM To investigate the protective effects of the natural medicinal monomer ecdysterone (ECR) with estrogenic activity against oxidative damage in human lens epithelial cells B3 (HLE-B3) caused by hydrogen peroxide 21(H2O2) and to pursue the possible mitochondrial proteomic regularity of the protective effects. METHODS HLE-B3 cells were treated with H2O2 (300µmol/L), β-estuarial (E2; 10(-8)mol/L) and H2O2, ECR (10(-6)mol/L) and H2O2, or left untreated. Altered expression of all mitochondrial proteins was analyzed by protein array and surface-enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS). The mass/charge (M/Z) ratios of each peak were tested by the Kruskal-Wallis rank sum test, and the protein peak value of the M/Z ratio for each treatment by pair comparison was analyzed with the Nemenyi test. RESULTS H2O2 up-regulated expression of two protein spots (with M/Z of 6 532 and 6 809). When E2 mitigated the oxidative damage, the expression of one protein spot (M/Z 6 532) was down-regulated. In contrast, ECR down-regulated both of protein spots (M/Z 6 532 and 6 809). CONCLUSION ECR could effectively inhibite H2O2 induced oxidative damage in HLE-B3 cells. The protein spot at M/Z of 6 532 might be the target spot of ECR against oxidative damage induced by H2O2.
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Affiliation(s)
- Chun-Yan Feng
- Department of Ophthalmology, Second Affiliated Peoples Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou 350003, Fujian Province, China
| | - Xiu-Rong Huang
- Research Center of Pathophysiology, Fujian University of Traditional Chinese Medicine, Fuzhou 350003, Fujian Province, China
| | - Ming-Xin Qi
- Department of Ophthalmology, Second Affiliated Peoples Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou 350003, Fujian Province, China
| | - Song-Wen Tang
- Research Center of Pathophysiology, Fujian University of Traditional Chinese Medicine, Fuzhou 350003, Fujian Province, China
| | - Sheng Chen
- Department of Ophthalmology, Second Affiliated Peoples Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou 350003, Fujian Province, China
| | - Yan-Hong Hu
- Department of Ophthalmology, Second Affiliated Peoples Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou 350003, Fujian Province, China
| | - Fa-Jie Ke
- Department of Ophthalmology, Second Affiliated Peoples Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou 350003, Fujian Province, China
| | - Xin Wang
- Department of Laboratory, Fujian University of Traditional Chinese Medicine subsidiary Rehabilitation Hospital, Fuzhou 350003, Fujian Province, China
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97
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Adijanto J, Philp NJ. Cultured primary human fetal retinal pigment epithelium (hfRPE) as a model for evaluating RPE metabolism. Exp Eye Res 2014; 126:77-84. [PMID: 24485945 DOI: 10.1016/j.exer.2014.01.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 12/20/2022]
Abstract
Mitochondrial dysfunction has been shown to contribute to age-related and proliferative retinal diseases. Over the past decade, the primary human fetal RPE (hfRPE) culture model has emerged as an effective tool for studying RPE function and mechanisms of retinal diseases. This model system has been rigorously characterized and shown to closely resemble native RPE cells at the genomic and protein level, and that they are capable of accomplishing the characteristic functions of a healthy native RPE (e.g., rod phagocytosis, ion and fluid transport, and retinoid cycle). In this review, we demonstrated that the metabolic activity of the RPE is an indicator of its health and state of differentiation, and present the hfRPE culture model as a valuable in vitro system for evaluating RPE metabolism in the context of RPE differentiation and retinal disease.
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Affiliation(s)
- Jeffrey Adijanto
- Thomas Jefferson University, Dept. of Pathology, Anatomy, & Cell Biology, 1020 Locust Street, Rm315, Philadelphia, PA 19107, USA.
| | - Nancy J Philp
- Thomas Jefferson University, Dept. of Pathology, Anatomy, & Cell Biology, 1020 Locust Street, Rm315, Philadelphia, PA 19107, USA.
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98
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Dhillon VS, Fenech M. Mutations that affect mitochondrial functions and their association with neurodegenerative diseases. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2013; 759:1-13. [PMID: 24055911 DOI: 10.1016/j.mrrev.2013.09.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 09/05/2013] [Accepted: 09/08/2013] [Indexed: 12/20/2022]
Abstract
Mitochondria are essential for mammalian and human cell function as they generate ATP via aerobic respiration. The proteins required in the electron transport chain are mainly encoded by the circular mitochondrial genome but other essential mitochondrial proteins such as DNA repair genes, are coded in the nuclear genome and require transport into the mitochondria. In this review we summarize current knowledge on the association of point mutations and deletions in the mitochondrial genome that are detrimental to mitochondrial function and are associated with accelerated ageing and neurological disorders including Alzheimer's, Parkinson's, Huntington's and Amyotrophic lateral sclerosis (ALS). Mutations in the nuclear encoded genes that disrupt mitochondrial functions are also discussed. It is evident that a greater understanding of the causes of mutations that adversely affect mitochondrial metabolism is required to develop preventive measures against accelerated ageing and neurological disorders caused by mitochondrial dysfunction.
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Affiliation(s)
- Varinderpal S Dhillon
- Preventative-Health Flagship, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia; CSIRO Animal, Food and Health Sciences, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia.
| | - Michael Fenech
- Preventative-Health Flagship, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia; CSIRO Animal, Food and Health Sciences, Gate 13, Kintore Avenue, Adelaide, SA 5000, Australia
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99
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Alterations in energy metabolism, neuroprotection and visual signal transduction in the retina of Parkinsonian, MPTP-treated monkeys. PLoS One 2013; 8:e74439. [PMID: 24040246 PMCID: PMC3764107 DOI: 10.1371/journal.pone.0074439] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 08/01/2013] [Indexed: 11/27/2022] Open
Abstract
Parkinson disease is mainly characterized by the degeneration of dopaminergic neurons in the central nervous system, including the retina. Different interrelated molecular mechanisms underlying Parkinson disease-associated neuronal death have been put forward in the brain, including oxidative stress and mitochondrial dysfunction. Systemic injection of the proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to monkeys elicits the appearance of a parkinsonian syndrome, including morphological and functional impairments in the retina. However, the intracellular events leading to derangement of dopaminergic and other retinal neurons in MPTP-treated animal models have not been so far investigated. Here we have used a comparative proteomics approach to identify proteins differentially expressed in the retina of MPTP-treated monkeys. Proteins were solubilized from the neural retinas of control and MPTP-treated animals, labelled separately with two different cyanine fluorophores and run pairwise on 2D DIGE gels. Out of >700 protein spots resolved and quantified, 36 were found to exhibit statistically significant differences in their expression levels, of at least ±1.4-fold, in the parkinsonian monkey retina compared with controls. Most of these spots were excised from preparative 2D gels, trypsinized and subjected to MALDI-TOF MS and LC-MS/MS analyses. Data obtained were used for protein sequence database interrogation, and 15 different proteins were successfully identified, of which 13 were underexpressed and 2 overexpressed. These proteins were involved in key cellular functional pathways such as glycolysis and mitochondrial electron transport, neuronal protection against stress and survival, and phototransduction processes. These functional categories underscore that alterations in energy metabolism, neuroprotective mechanisms and signal transduction are involved in MPTP-induced neuronal degeneration in the retina, in similarity to mechanisms thought to underlie neuronal death in the Parkinson’s diseased brain and neurodegenerative diseases of the retina proper.
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100
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Semba RD, Enghild JJ, Venkatraman V, Dyrlund TF, Van Eyk JE. The Human Eye Proteome Project: perspectives on an emerging proteome. Proteomics 2013; 13:2500-11. [PMID: 23749747 PMCID: PMC3978387 DOI: 10.1002/pmic.201300075] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/26/2013] [Accepted: 05/15/2013] [Indexed: 12/22/2022]
Abstract
There are an estimated 285 million people with visual impairment worldwide, of whom 39 million are blind. The pathogenesis of many eye diseases remains poorly understood. The human eye is currently an emerging proteome that may provide key insight into the biological pathways of disease. We review proteomic investigations of the human eye and present a catalogue of 4842 nonredundant proteins identified in human eye tissues and biofluids to date. We highlight the need to identify new biomarkers for eye diseases using proteomics. Recent advances in proteomics do now allow the identification of hundreds to thousands of proteins in tissues and fluids, characterization of various PTMs and simultaneous quantification of multiple proteins. To facilitate proteomic studies of the eye, the Human Eye Proteome Project (HEPP) was organized in September 2012. The HEPP is one of the most recent components of the Biology/Disease-driven Human Proteome Project (B/D-HPP) whose overarching goal is to support the broad application of state-of-the-art measurements of proteins and proteomes by life scientists studying the molecular mechanisms of biological processes and human disease. The large repertoire of investigative proteomic tools has great potential to transform vision science and enhance understanding of physiology and disease processes that affect sight.
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Affiliation(s)
- Richard D Semba
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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