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Liu D, Liu Z, Liao H, Chen ZS, Qin B. Ferroptosis as a potential therapeutic target for age-related macular degeneration. Drug Discov Today 2024; 29:103920. [PMID: 38369100 DOI: 10.1016/j.drudis.2024.103920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/11/2024] [Accepted: 02/14/2024] [Indexed: 02/20/2024]
Abstract
Cell death plays a crucial part in the process of age-related macular degeneration (AMD), but its mechanisms remain elusive. Accumulating evidence suggests that ferroptosis, a novel form of regulatory cell death characterized by iron-dependent accumulation of lipid hydroperoxides, has a crucial role in the pathogenesis of AMD. Numerous studies have suggested that ferroptosis participates in the degradation of retinal cells and accelerates the progression of AMD. Furthermore, inhibitors of ferroptosis exhibit notable protective effects in AMD, underscoring the significance of ferroptosis as a pivotal mechanism in the death of retinal cells during the process of AMD. This review aims to summarize the molecular mechanisms of ferroptosis in AMD, enumerate potential inhibitors and discuss the challenges and future opportunities associated with targeting ferroptosis as a therapeutic strategy, providing important information references and insights for the prevention and treatment of AMD.
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Affiliation(s)
- Dongcheng Liu
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Aier Ophthalmic Technology Institute, Shenzhen, China
| | - Ziling Liu
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Aier Ophthalmic Technology Institute, Shenzhen, China
| | - Hongxia Liao
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Aier Ophthalmic Technology Institute, Shenzhen, China
| | - Zhe-Sheng Chen
- College of Pharmacy and Health Sciences, St. John's University, Queens, New York, USA.
| | - Bo Qin
- Shenzhen Aier Eye Hospital, Aier Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Aier Ophthalmic Technology Institute, Shenzhen, China; Aier Eye Hospital, Tianjin University, Tianjin, China.
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2
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Landowski M, Gogoi P, Ikeda S, Ikeda A. Roles of transmembrane protein 135 in mitochondrial and peroxisomal functions - implications for age-related retinal disease. FRONTIERS IN OPHTHALMOLOGY 2024; 4:1355379. [PMID: 38576540 PMCID: PMC10993500 DOI: 10.3389/fopht.2024.1355379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Aging is the most significant risk factor for age-related diseases in general, which is true for age-related diseases in the eye including age-related macular degeneration (AMD). Therefore, in order to identify potential therapeutic targets for these diseases, it is crucial to understand the normal aging process and how its mis-regulation could cause age-related diseases at the molecular level. Recently, abnormal lipid metabolism has emerged as one major aspect of age-related symptoms in the retina. Animal models provide excellent means to identify and study factors that regulate lipid metabolism in relation to age-related symptoms. Central to this review is the role of transmembrane protein 135 (TMEM135) in the retina. TMEM135 was identified through the characterization of a mutant mouse strain exhibiting accelerated retinal aging and positional cloning of the responsible mutation within the gene, indicating the crucial role of TMEM135 in regulating the normal aging process in the retina. Over the past decade, the molecular functions of TMEM135 have been explored in various models and tissues, providing insights into the regulation of metabolism, particularly lipid metabolism, through its action in multiple organelles. Studies indicated that TMEM135 is a significant regulator of peroxisomes, mitochondria, and their interaction. Here, we provide an overview of the molecular functions of TMEM135 which is crucial for regulating mitochondria, peroxisomes, and lipids. The review also discusses the age-dependent phenotypes in mice with TMEM135 perturbations, emphasizing the importance of a balanced TMEM135 function for the health of the retina and other tissues including the heart, liver, and adipose tissue. Finally, we explore the potential roles of TMEM135 in human age-related retinal diseases, connecting its functions to the pathobiology of AMD.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Purnima Gogoi
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
| | - Sakae Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
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3
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Różanowska MB. Lipofuscin, Its Origin, Properties, and Contribution to Retinal Fluorescence as a Potential Biomarker of Oxidative Damage to the Retina. Antioxidants (Basel) 2023; 12:2111. [PMID: 38136230 PMCID: PMC10740933 DOI: 10.3390/antiox12122111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Lipofuscin accumulates with age as intracellular fluorescent granules originating from incomplete lysosomal digestion of phagocytosed and autophagocytosed material. The purpose of this review is to provide an update on the current understanding of the role of oxidative stress and/or lysosomal dysfunction in lipofuscin accumulation and its consequences, particularly for retinal pigment epithelium (RPE). Next, the fluorescence of lipofuscin, spectral changes induced by oxidation, and its contribution to retinal fluorescence are discussed. This is followed by reviewing recent developments in fluorescence imaging of the retina and the current evidence on the prognostic value of retinal fluorescence for the progression of age-related macular degeneration (AMD), the major blinding disease affecting elderly people in developed countries. The evidence of lipofuscin oxidation in vivo and the evidence of increased oxidative damage in AMD retina ex vivo lead to the conclusion that imaging of spectral characteristics of lipofuscin fluorescence may serve as a useful biomarker of oxidative damage, which can be helpful in assessing the efficacy of potential antioxidant therapies in retinal degenerations associated with accumulation of lipofuscin and increased oxidative stress. Finally, amendments to currently used fluorescence imaging instruments are suggested to be more sensitive and specific for imaging spectral characteristics of lipofuscin fluorescence.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, College of Biomedical and Life Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, Wales, UK;
- Cardiff Institute for Tissue Engineering and Repair (CITER), Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK
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4
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Brooks CD, Kodati B, Stankowska DL, Krishnamoorthy RR. Role of mitophagy in ocular neurodegeneration. Front Neurosci 2023; 17:1299552. [PMID: 37965225 PMCID: PMC10641468 DOI: 10.3389/fnins.2023.1299552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 10/12/2023] [Indexed: 11/16/2023] Open
Abstract
Neurons in the central nervous system are among the most metabolically active cells in the body, characterized by high oxygen consumption utilizing glucose both aerobically and anaerobically. Neurons have an abundance of mitochondria which generate adequate ATP to keep up with the high metabolic demand. One consequence of the oxidative phosphorylation mechanism of ATP synthesis, is the generation of reactive oxygen species which produces cellular injury as well as damage to mitochondria. Mitochondria respond to injury by fusion which serves to ameliorate the damage through genetic complementation. Mitochondria also undergo fission to meet an increased energy demand. Loss of mitochondria is also compensated by increased biogenesis to generate new mitochondria. Damaged mitochondria are removed by mitophagy, an autophagic process, in which damaged mitochondria are surrounded by a membrane to form an autophagosome which ultimately fuses with the lysosome resulting in degradation of faulty mitochondria. Dysregulation of mitophagy has been reported in several central nervous system disorders, including, Alzheimer's disease and Parkinson's disease. Recent studies point to aberrant mitophagy in ocular neurodegenerative disorders which could be an important contributor to the disease etiology/pathology. This review article highlights some of the recent findings that point to dysregulation of mitophagy and it's underlying mechanisms in ocular neurodegenerative diseases, including, glaucoma, age-related macular degeneration and diabetic retinopathy.
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Affiliation(s)
- Calvin D. Brooks
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Bindu Kodati
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Dorota L. Stankowska
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Raghu R. Krishnamoorthy
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
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5
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Wada I, Mori K, Sreekumar PG, Ji R, Spee C, Hong E, Ishikawa K, Sonoda KH, Kannan R. Characterization and contribution of RPE senescence to Age-related macular degeneration in Tnfrsf10 knock out mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.552052. [PMID: 37577701 PMCID: PMC10418235 DOI: 10.1101/2023.08.04.552052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Background Retinal pigment epithelial cells (RPE) play vital role in the pathogenesis of age-related macular degeneration (AMD). Our laboratory has shown that RPE cellular senescence contributed to the pathophysiology of experimental AMD, and SASP members are involved in this process. Recently, we presented confirmatory evidence to earlier GWAS studies that dysregulation of tumor necrosis factor receptor superfamily 10A (TNFRSF10A) dysregulation leads to AMD development and is linked to RPE dysfunction. This study aims to investigate the contribution of RPE senescence to AMD pathophysiology using TNFRSF10A silenced human RPE (hRPE) cells and Tnfrsf10 KO mice. Methods Sub-confluent primary hRPE cells and TNFRSF10A silenced hRPE were exposed to stress-induced premature senescence with H2O2 (500 μM, 48h), and senescence-associated markers (βgal, p16, and p21) were analyzed by RT-PCR and WB analysis. The effect of H2O2-induced senescence in non-silenced and silenced hRPE on OXPHOS and glycolysis was determined using Seahorse XF96 analyzer. Male C57BL/6J Tnfrsf10 KO ( Tnfrsf10 -/- ) mice were used to study the regulation of senescence by TNFRSF10A in vivo . Expression of p16 and p21 in control and KO mice of varying ages were determined by RT-PCR, WB, and immunostaining analysis. Results The senescence-associated p16 and p21 showed a significant ( p < 0.01) upregulation with H2O2 induction at the gene (1.8- and 3-fold) and protein (3.2- and 4-fold) levels in hRPE cells. The protein expression of p16 and p21 was further significantly increased by co-treatment with siRNA ( p < 0.05 vs. H2O2). Mitochondrial oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) (pmol/min/total DNA) increased with senescence induction by H2O2 for 48h in control RPE, and knockdown of TNFRSF10A caused a further increase in OCR and ECAR. In addition, co-treatment with PKC activator significantly improved all parameters. Similarly, in vivo studies showed upregulation of p16 and p21 by RT-PCR, WB, and immunostaining analysis in RPE/choroid of Tnfrsf10 KO mice. When subjected to examination across distinct age groups, namely young (1-3 months), middle (6-9 months), and old (12-15 months) mice, a discernible age-related elevation in the expression of p16 and p21 was observed. Conclusions Our findings suggest that TNRSF10A is a regulator of regulates in RPE senescence. Further work on elucidating pathways of senescence will facilitate the development of new therapeutic targets for AMD.
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Piri N, Kaplan HJ. Role of Complement in the Onset of Age-Related Macular Degeneration. Biomolecules 2023; 13:biom13050832. [PMID: 37238702 DOI: 10.3390/biom13050832] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive degenerative disease of the central retina and the leading cause of severe loss of central vision in people over age 50. Patients gradually lose central visual acuity, compromising their ability to read, write, drive, and recognize faces, all of which greatly impact daily life activities. Quality of life is significantly affected in these patients, and there are worse levels of depression as a result. AMD is a complex, multifactorial disease in which age and genetics, as well as environmental factors, all play a role in its development and progression. The mechanism by which these risk factors interact and converge towards AMD are not fully understood, and therefore, drug discovery is challenging, with no successful therapeutic attempt to prevent the development of this disease. In this review, we describe the pathophysiology of AMD and review the role of complement, which is a major risk factor in the development of AMD.
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Affiliation(s)
- Niloofar Piri
- Department of Ophthalmology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Henry J Kaplan
- Departments of Ophthalmology and Biochemistry & Molecular Biology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
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Hammadi S, Tzoumas N, Ferrara M, Meschede IP, Lo K, Harris C, Lako M, Steel DH. Bruch's Membrane: A Key Consideration with Complement-Based Therapies for Age-Related Macular Degeneration. J Clin Med 2023; 12:2870. [PMID: 37109207 PMCID: PMC10145879 DOI: 10.3390/jcm12082870] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/29/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
The complement system is crucial for immune surveillance, providing the body's first line of defence against pathogens. However, an imbalance in its regulators can lead to inappropriate overactivation, resulting in diseases such as age-related macular degeneration (AMD), a leading cause of irreversible blindness globally affecting around 200 million people. Complement activation in AMD is believed to begin in the choriocapillaris, but it also plays a critical role in the subretinal and retinal pigment epithelium (RPE) spaces. Bruch's membrane (BrM) acts as a barrier between the retina/RPE and choroid, hindering complement protein diffusion. This impediment increases with age and AMD, leading to compartmentalisation of complement activation. In this review, we comprehensively examine the structure and function of BrM, including its age-related changes visible through in vivo imaging, and the consequences of complement dysfunction on AMD pathogenesis. We also explore the potential and limitations of various delivery routes (systemic, intravitreal, subretinal, and suprachoroidal) for safe and effective delivery of conventional and gene therapy-based complement inhibitors to treat AMD. Further research is needed to understand the diffusion of complement proteins across BrM and optimise therapeutic delivery to the retina.
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Affiliation(s)
- Sarah Hammadi
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Nikolaos Tzoumas
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Sunderland Eye Infirmary, Queen Alexandra Rd., Sunderland SR2 9H, UK
| | | | - Ingrid Porpino Meschede
- Gyroscope Therapeutics Limited, a Novartis Company, Rolling Stock Yard, 6th Floor, 188 York Way, London N7 9AS, UK
| | - Katharina Lo
- Gyroscope Therapeutics Limited, a Novartis Company, Rolling Stock Yard, 6th Floor, 188 York Way, London N7 9AS, UK
| | - Claire Harris
- Gyroscope Therapeutics Limited, a Novartis Company, Rolling Stock Yard, 6th Floor, 188 York Way, London N7 9AS, UK
- Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Majlinda Lako
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - David H. Steel
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
- Sunderland Eye Infirmary, Queen Alexandra Rd., Sunderland SR2 9H, UK
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8
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Millington-Ward S, Chadderton N, Finnegan LK, Post IJM, Carrigan M, Nixon R, Humphries MM, Humphries P, Kenna PF, Palfi A, Farrar GJ. RPE-Directed Gene Therapy Improves Mitochondrial Function in Murine Dry AMD Models. Int J Mol Sci 2023; 24:ijms24043847. [PMID: 36835257 PMCID: PMC9968062 DOI: 10.3390/ijms24043847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 02/17/2023] Open
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness in the aged population. However, to date there is no effective treatment for the dry form of the disease, representing 85-90% of cases. AMD is an immensely complex disease which affects, amongst others, both retinal pigment epithelium (RPE) and photoreceptor cells and leads to the progressive loss of central vision. Mitochondrial dysfunction in both RPE and photoreceptor cells is emerging as a key player in the disease. There are indications that during disease progression, the RPE is first impaired and RPE dysfunction in turn leads to subsequent photoreceptor cell degeneration; however, the exact sequence of events has not as yet been fully determined. We recently showed that AAV delivery of an optimised NADH-ubiquinone oxidoreductase (NDI1) gene, a nuclear-encoded complex 1 equivalent from S. cerevisiae, expressed from a general promoter, provided robust benefit in a variety of murine and cellular models of dry AMD; this was the first study employing a gene therapy to directly boost mitochondrial function, providing functional benefit in vivo. However, use of a restricted RPE-specific promoter to drive expression of the gene therapy enables exploration of the optimal target retinal cell type for dry AMD therapies. Furthermore, such restricted transgene expression could reduce potential off-target effects, possibly improving the safety profile of the therapy. Therefore, in the current study, we interrogate whether expression of the gene therapy from the RPE-specific promoter, Vitelliform macular dystrophy 2 (VMD2), might be sufficient to rescue dry AMD models.
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Affiliation(s)
- Sophia Millington-Ward
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
- Correspondence:
| | - Naomi Chadderton
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Laura K. Finnegan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Iris J. M. Post
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Matthew Carrigan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Rachel Nixon
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Marian M. Humphries
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Pete Humphries
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Paul F. Kenna
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
- The Research Foundation, Royal Victoria Eye and Ear Hospital, D02 XK51 Dublin, Ireland
| | - Arpad Palfi
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - G. Jane Farrar
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
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Guo J, Huang X, Dou L, Yan M, Shen T, Tang W, Li J. Aging and aging-related diseases: from molecular mechanisms to interventions and treatments. Signal Transduct Target Ther 2022; 7:391. [PMID: 36522308 PMCID: PMC9755275 DOI: 10.1038/s41392-022-01251-0] [Citation(s) in RCA: 182] [Impact Index Per Article: 91.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/03/2022] [Accepted: 11/10/2022] [Indexed: 12/23/2022] Open
Abstract
Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.
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Affiliation(s)
- Jun Guo
- grid.506261.60000 0001 0706 7839The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, 100730 China
| | - Xiuqing Huang
- grid.506261.60000 0001 0706 7839The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, 100730 China
| | - Lin Dou
- grid.506261.60000 0001 0706 7839The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, 100730 China
| | - Mingjing Yan
- grid.506261.60000 0001 0706 7839The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, 100730 China
| | - Tao Shen
- grid.506261.60000 0001 0706 7839The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, 100730 China
| | - Weiqing Tang
- grid.506261.60000 0001 0706 7839The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, 100730 China
| | - Jian Li
- grid.506261.60000 0001 0706 7839The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, 100730 China
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10
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Fisher CR, Shaaeli AA, Ebeling MC, Montezuma SR, Ferrington DA. Investigating mitochondrial fission, fusion, and autophagy in retinal pigment epithelium from donors with age-related macular degeneration. Sci Rep 2022; 12:21725. [PMID: 36526679 PMCID: PMC9758189 DOI: 10.1038/s41598-022-26012-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in developed countries, characterized by the death of retinal pigment epithelial (RPE) cells and photoreceptors. Previous studies report an accumulation of damaged and dysfunctional mitochondria in RPE of human donors with AMD. Understanding how damaged mitochondria accumulate in AMD is an important step in discovering disease mechanisms and identifying therapeutic targets. In this report, we assessed mitochondrial fission and fusion by quantifying proteins and measured mitochondrial autophagy (mitophagy) via protein analysis and advanced imaging techniques using mitochondrial targeted mKeima in primary human RPE from donors with or without AMD. We report disease-specific differences in mitochondrial proteins that regulate fission, fusion, and mitophagy that were present at baseline and with treatments to stimulate these pathways. Data suggest AMD RPE utilize receptor-mediated mitophagy as a compensatory mechanism for deficits in the ubiquitin-mediated mitophagy pathway. These changes in mitochondrial homeostasis could lead to the buildup of damaged and dysfunctional mitochondria observed in the RPE of AMD donors.
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Affiliation(s)
- Cody R. Fisher
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455 USA
| | - Adam A. Shaaeli
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Undergraduate program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455 USA
| | - Mara C. Ebeling
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA
| | - Sandra R. Montezuma
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA
| | - Deborah A. Ferrington
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455 USA ,grid.280881.b0000 0001 0097 5623Doheny Eye Institute, Pasadena, CA 91103 USA
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11
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Malek G, Campisi J, Kitazawa K, Webster C, Lakkaraju A, Skowronska-Krawczyk D. Does senescence play a role in age-related macular degeneration? Exp Eye Res 2022; 225:109254. [PMID: 36150544 PMCID: PMC10032649 DOI: 10.1016/j.exer.2022.109254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 09/07/2022] [Accepted: 09/14/2022] [Indexed: 12/29/2022]
Abstract
Advanced age is the most established risk factor for developing age-related macular degeneration (AMD), one of the leading causes of visual impairment in the elderly, in Western and developed countries. Similarly, after middle age, there is an exponential increase in pathologic molecular and cellular events that can induce senescence, traditionally defined as an irreversible loss of the cells' ability to divide and most recently reported to also occur in select post-mitotic and terminally differentiated cells, such as neurons. Together these facts raise the question as to whether or not cellular senescence, may play a role in the development of AMD. A number of studies have reported the effect of ocular-relevant inducers of senescence using primarily in vitro models of poorly polarized, actively dividing retinal pigment epithelial (RPE) cell lines. However, in interpretating the data, the fidelity of these culture models to the RPE in vivo, must be considered. Fewer studies have explored the presence and/or impact of senescent cells in in vivo models that present with phenotypic features of AMD, leaving this an open field for further investigation. The goal of this review is to discuss current thoughts on the potential role of senescence in AMD development and progression, with consideration of the model systems used and their relevance to human disease.
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Affiliation(s)
- Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
| | - Judith Campisi
- Buck Institute for Research on Aging, Novato, CA, USA; Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Koji Kitazawa
- Buck Institute for Research on Aging, Novato, CA, USA; Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Corey Webster
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Aparna Lakkaraju
- Departments of Ophthalmology and Anatomy, School of Medicine, University of California, San Francisco, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Physiology and Biophysics, Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, University of California, Irvine, CA, USA
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12
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Bharti K, den Hollander AI, Lakkaraju A, Sinha D, Williams DS, Finnemann SC, Bowes-Rickman C, Malek G, D'Amore PA. Cell culture models to study retinal pigment epithelium-related pathogenesis in age-related macular degeneration. Exp Eye Res 2022; 222:109170. [PMID: 35835183 PMCID: PMC9444976 DOI: 10.1016/j.exer.2022.109170] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/23/2022] [Accepted: 06/29/2022] [Indexed: 11/04/2022]
Abstract
Age-related macular degeneration (AMD) is a disease that affects the macula - the central part of the retina. It is a leading cause of irreversible vision loss in the elderly. AMD onset is marked by the presence of lipid- and protein-rich extracellular deposits beneath the retinal pigment epithelium (RPE), a monolayer of polarized, pigmented epithelial cells located between the photoreceptors and the choroidal blood supply. Progression of AMD to the late nonexudative "dry" stage of AMD, also called geographic atrophy, is linked to progressive loss of areas of the RPE, photoreceptors, and underlying choriocapillaris leading to a severe decline in patients' vision. Differential susceptibility of macular RPE in AMD and the lack of an anatomical macula in most lab animal models has promoted the use of in vitro models of the RPE. In addition, the need for high throughput platforms to test potential therapies has driven the creation and characterization of in vitro model systems that recapitulate morphologic and functional abnormalities associated with human AMD. These models range from spontaneously formed cell line ARPE19, immortalized cell lines such as hTERT-RPE1, RPE-J, and D407, to primary human (fetal or adult) or animal (mouse and pig) RPE cells, and embryonic and induced pluripotent stem cell (iPSC) derived RPE. Hallmark RPE phenotypes, such as cobblestone morphology, pigmentation, and polarization, vary significantly betweendifferent models and culture conditions used in different labs, which would directly impact their usability for investigating different aspects of AMD biology. Here the AMD Disease Models task group of the Ryan Initiative for Macular Research (RIMR) provides a summary of several currently used in vitro RPE models, historical aspects of their development, RPE phenotypes that are attainable in these models, their ability to model different aspects of AMD pathophysiology, and pros/cons for their use in the RPE and AMD fields. In addition, due to the burgeoning use of iPSC derived RPE cells, the critical need for developing standards for differentiating and rigorously characterizing RPE cell appearance, morphology, and function are discussed.
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Affiliation(s)
- Kapil Bharti
- Ocular and Stem Cell Translational Research Section, National Eye Institute, NIH, Bethesda, MD, USA.
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands; AbbVie, Genomics Research Center, Cambridge, MA, USA.
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, USA.
| | - Debasish Sinha
- Department of Ophthalmology, Cell Biology and Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - David S Williams
- Stein Eye Institute, Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| | - Silvia C Finnemann
- Center of Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY, USA.
| | - Catherine Bowes-Rickman
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA.
| | - Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
| | - Patricia A D'Amore
- Mass Eye and Ear, Departments of Ophthalmology and Pathology, Harvard Medical School, Boston, MA, USA.
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Fehér J, Élő Á, István L, Nagy ZZ, Radák Z, Scuderi G, Artico M, Kovács I. Microbiota mitochondria disorders as hubs for early age-related macular degeneration. GeroScience 2022; 44:2623-2653. [PMID: 35978068 PMCID: PMC9385247 DOI: 10.1007/s11357-022-00620-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 07/01/2022] [Indexed: 01/07/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive neurodegenerative disease affecting the central area (macula lutea) of the retina. Research on the pathogenic mechanism of AMD showed complex cellular contribution governed by such risk factors as aging, genetic predisposition, diet, and lifestyle. Recent studies suggested that microbiota is a transducer and a modifier of risk factors for neurodegenerative diseases, and mitochondria may be one of the intracellular targets of microbial signaling molecules. This review explores studies supporting a new concept on the contribution of microbiota-mitochondria disorders to AMD. We discuss metabolic, vascular, immune, and neuronal mechanism in AMD as well as key alterations of photoreceptor cells, retinal pigment epithelium (RPE), Bruch's membrane, choriocapillaris endothelial, immune, and neuronal cells. Special attention was paid to alterations of mitochondria contact sites (MCSs), an organelle network of mitochondria, endoplasmic reticulum, lipid droplets (LDs), and peroxisomes being documented based on our own electron microscopic findings from surgically removed human eyes. Morphometry of Bruch's membrane lipids and proteoglycans has also been performed in early AMD and aged controls. Microbial metabolites (short-chain fatty acids, polyphenols, and secondary bile acids) and microbial compounds (lipopolysaccharide, peptidoglycan, and bacterial DNA)-now called postbiotics-in addition to local effects on resident microbiota and mucous membrane, regulate systemic metabolic, vascular, immune, and neuronal mechanisms in normal conditions and in various common diseases. We also discuss their antioxidant, anti-inflammatory, and metabolic effects as well as experimental and clinical observations on regulating the main processes of photoreceptor renewal, mitophagy, and autophagy in early AMD. These findings support an emerging concept that microbiota-mitochondria disorders may be a crucial pathogenic mechanism of early AMD; and similarly, to other age-related neurodegenerative diseases, new treatment approaches should be targeted at these disorders.
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Affiliation(s)
- János Fehér
- PRIMAVERA Program, Nutripharma Hungaria Ltd., Budapest, Hungary
| | - Ágnes Élő
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Lilla István
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zoltán Zsolt Nagy
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zsolt Radák
- grid.472475.70000 0000 9243 1481Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Gianluca Scuderi
- grid.7841.aOphthalmology Unit, NESMOS Department, Sant’Andrea Hospital, Faculty of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
| | - Marco Artico
- grid.417007.5Department of Sensory Organs, “Sapienza” University of Rome, Roma, Italy
| | - Illés Kovács
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary ,grid.5386.8000000041936877XDepartment of Ophthalmology, Weill Cornell Medical College, New York City, NY USA
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14
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Mettu PS, Allingham MJ, Cousins SW. Phase 1 Clinical Trial of Elamipretide in Dry Age-Related Macular Degeneration and Noncentral Geographic Atrophy: ReCLAIM NCGA Study. OPHTHALMOLOGY SCIENCE 2022; 2:100086. [PMID: 36246181 PMCID: PMC9560640 DOI: 10.1016/j.xops.2021.100086] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 11/01/2021] [Accepted: 11/23/2021] [Indexed: 11/04/2022]
Abstract
Purpose Assess the safety, tolerability, and feasibility of subcutaneous administration of the mitochondrial-targeted drug elamipretide in patients with dry age-related macular degeneration (AMD) and noncentral geographic atrophy (NCGA) and to perform exploratory analyses of change in visual function. Design Phase 1, single-center, open-label, 24-week clinical trial with preplanned NCGA cohort. Participants Adults ≥ 55 years of age with dry AMD and NCGA. Methods Participants received subcutaneous elamipretide 40-mg daily; safety and tolerability assessed throughout. Ocular assessments included normal-luminance best-corrected visual acuity (BCVA), low-luminance BCVA (LLBCVA), normal-luminance binocular reading acuity (NLBRA), low-luminance binocular reading acuity (LLBRA), spectral-domain OCT, fundus autofluorescence (FAF), and patient self-reported function by low-luminance questionnaire (LLQ). Main Outcome Measures Primary end point was safety and tolerability. Prespecified exploratory end-points included changes in BCVA, LLBCVA, NLBRA, LLBRA, geographic atrophy (GA) area, and LLQ. Results Subcutaneous elamipretide was highly feasible. All participants (n = 19) experienced 1 or more nonocular adverse events (AEs), but all AEs were either mild (73.7%) or moderate (26.3%); no serious AEs were noted. Two participants exited the study because of AEs (conversion to neovascular AMD, n = 1; intolerable injection site reaction, n = 1), 1 participant discontinued because of self-perceived lack of efficacy, and 1 participant chose not to continue with study visits. Among participants completing the study (n = 15), mean ± standard deviation (SD) change in BCVA from baseline to week 24 was +4.6 (5.1) letters (P = 0.0032), while mean change (SD) in LLBCVA was +5.4 ± 7.9 letters (P = 0.0245). Although minimal change in NLBRA occurred, mean ± SD change in LLBCVA was -0.52 ± 0.75 logarithm of the minimum angle of resolution units (P = 0.005). Mean ± SD change in GA area (square root transformation) from baseline to week 24 was 0.14 ± 0.08 mm by FAF and 0.13 ± 0.14 mm by OCT. Improvement was observed in LLQ for dim light reading and general dim light vision. Conclusions Elamipretide seems to be well tolerated without serious AEs in patients with dry AMD and NCGA. Exploratory analyses demonstrated possible positive effect on visual function, particularly under low luminance. A Phase 2b trial is underway to evaluate elamipretide further in dry AMD and NCGA.
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Key Words
- AE, adverse event
- AMD, age-related macular degeneration
- BCVA, best-corrected visual acuity
- Dry age-related macular degeneration
- ETDRS, Early Treatment Diabetic Retinopathy Study
- Elamipretide
- FAF, fundus autofluorescence
- GA, geographic atrophy
- Geographic atrophy
- LLBCVA, low-luminance best-corrected visual acuity
- LLBRA, low-luminance binocular reading acuity
- LLQ, low-luminance questionnaire
- Mitochondrial dysfunction
- NCGA, noncentral geographic atrophy
- NLBRA, normal-luminance binocular reading acuity
- Phase 1 clinical trial
- RPE, retinal pigment epithelium
- SD, standard deviation
- logMAR, logarithm of the minimum angle of resolution
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Affiliation(s)
- Priyatham S. Mettu
- Duke Center for Macular Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, North Carolina
| | - Michael J. Allingham
- Duke Center for Macular Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, North Carolina
| | - Scott W. Cousins
- Duke Center for Macular Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, North Carolina
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15
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Allingham MJ, Mettu PS, Cousins SW. Phase 1 Clinical Trial of Elamipretide in Intermediate Age-Related Macular Degeneration and High-Risk Drusen. OPHTHALMOLOGY SCIENCE 2022; 2:100095. [PMID: 36246187 PMCID: PMC9560633 DOI: 10.1016/j.xops.2021.100095] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 10/29/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022]
Abstract
Purpose To assess safety, tolerability, and feasibility of subcutaneous administration of the mitochondrial-targeted drug elamipretide in patients with intermediate age-related macular degeneration (AMD) and high-risk drusen (HRD) and to perform exploratory analyses of change in visual function. Design Phase 1, single-center, open-label, 24-week clinical trial with preplanned HRD cohort. Participants Adult patients ≥55 years of age with intermediate AMD and HRD. Methods Participants received subcutaneous elamipretide 40 mg daily, with safety and tolerability assessed throughout the study. Ocular assessments included normal-luminance best-corrected visual acuity (BCVA), low-luminance best-corrected visual acuity (LLVA), normal-luminance binocular reading acuity (NLRA), low-luminance binocular reading acuity (LLRA), spectral-domain OCT, fundus autofluorescence (FAF), mesopic microperimetry, dark adaptation, and low-luminance questionnaire (LLQ). Main Outcome Measures The primary end point was safety and tolerability. Prespecified exploratory end points included changes from baseline in BCVA, LLVA, NLRA, LLRA, retinal pigment epithelium (RPE)-drusen complex (DC) volume by OCT, FAF, mesopic microperimetry, dark adaptation, and LLQ results. Results Subcutaneous administration of elamipretide was highly feasible. All participants with HRD (n = 21) experienced 1 or more adverse events (AEs), but all were mild (57%) or moderate (43%), with the most common events related to injection site reactions. No serious systemic AEs occurred. One participant discontinued because of injection site reaction, 1 participant withdrew because they did not wish to continue study visits, and 1 participant withdrew after experiencing transient visual impairment. Among the 18 participants who completed the study, mean change in BCVA from baseline to 24 weeks was +3.6 letters (P = 0.014) and LLVA was +5.6 letters (P = 0.004). Compared with baseline, mean NLRA improved by –0.11 logarithm of the minimum angle of resolution (logMAR) units (P = 0.001), and LLRA by −0.28 logMAR units (P < 0.0001). Significant improvements were found in 6 of 7 subscales of the LLQ (P<0.0015). No significant changes were observed for RPE-DC volume, FAF, mesopic microperimetry, or dark adaptation. Conclusions Elamipretide appeared to be generally safe and well tolerated in treating intermediate AMD and HRD. Exploratory analyses demonstrate a positive effect on visual function, particularly under low-luminance conditions. Further study of elamipretide for treatment of intermediate AMD with HRD is warranted.
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16
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Alam NM, Douglas RM, Prusky GT. Treatment of age-related visual impairment with a mitochondrial-acting peptide. Dis Model Mech 2021; 15:274438. [PMID: 34766182 PMCID: PMC8891924 DOI: 10.1242/dmm.048256] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 10/27/2021] [Indexed: 12/04/2022] Open
Abstract
Age-related visual decline and disease due to neural dysfunction are major sources of disability that have resisted effective treatment. In light of evidence that visual impairment and mitochondrial dysfunction advance with age, we characterized age-related decline of spatial visual function in mice and investigated whether treatment of aged mice with the mitochondrion-penetrating peptide elamipretide that has been reported to improve mitochondrial function, would improve it. Impaired photopic acuity measured by using a virtual optokinetic system emerged near 18 months and declined to ∼40% below normal by 34 months. Daily application of the synthetic peptide elamipretide, which has high selectivity for mitochondrial membranes that contain cardiolipin and promotes efficient electron transfer, was able to mitigate visual decline from 18 months onwards. Daily application from 24 months onwards, i.e. when acuity had reduced by ∼16%, reversed visual decline and normalized function within 2 months. Recovered function persisted for at least 3 months after treatment was withdrawn and a single treatment at 24 months delayed subsequent visual decline. Elamipretide applied daily from 32 months onwards took longer to take effect, but substantial improvement was found within 2 months. The effects of age and elamipretide treatment on contrast sensitivity were similar to those on acuity, systemic and eye drop applications of elamipretide had comparable effects, scotopic spatial visual function was largely unaffected by age or treatment, and altered function was independent of variation in optical clarity. These data indicate that elamipretide treatment adaptively alters the aging visual system. They also provide a rationale to investigate whether mitochondrial dysfunction is a treatable pathophysiology of human visual aging and age-related visual disease. Summary: Age-related decline in vision in mice is substantially prevented or restored in response to treatment with a peptide that comprises mitochondrial affinity and improves mitochondrial function.
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Affiliation(s)
- N M Alam
- Burke Neurological Institute, 785 Mamaroneck Avenue, White Plains, New York 10605, USA
| | - R M Douglas
- University of British Columbia, Department of Ophthalmology and Visual Sciences, 2550 Willow Street, Vancouver, BC V5Z 3N9, Canada
| | - G T Prusky
- Burke Neurological Institute, 785 Mamaroneck Avenue, White Plains, New York 10605, USA.,Weill Cornell Medicine, Department of Physiology and Biophysics, 1300 York Avenue, New York, NY 10065, USA
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17
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Armbrust KR, Karunadharma PP, Terluk MR, Kapphahn RJ, Olsen TW, Ferrington DA, Montezuma SR. No association between cataract surgery and mitochondrial DNA damage with age-related macular degeneration in human donor eyes. PLoS One 2021; 16:e0258803. [PMID: 34665838 PMCID: PMC8525771 DOI: 10.1371/journal.pone.0258803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 10/06/2021] [Indexed: 12/04/2022] Open
Abstract
Purpose To determine whether age-related macular degeneration (AMD) severity or the frequency of retinal pigment epithelium mitochondrial DNA lesions differ in human donor eyes that have undergone cataract surgery compared to phakic eyes. Methods Eyes from human donors aged ≥ 55 years were obtained from the Minnesota Lions Eye Bank. Cataract surgery status was obtained from history provided to Eye Bank personnel by family members at the time of tissue procurement. Donor eyes were graded for AMD severity using the Minnesota Grading System. Quantitative PCR was performed on DNA isolated from macular punches of retinal pigment epithelium to quantitate the frequency of mitochondrial DNA lesions in the donor tissue. Univariable and multivariable analyses were performed to evaluate for associations between (1) cataract surgery and AMD severity and (2) cataract surgery and mitochondrial DNA lesion frequency. Results A total of 157 subjects qualified for study inclusion. Multivariable analysis with age, sex, smoking status, and cataract surgery status showed that only age was associated with AMD grade. Multivariable analysis with age, sex, smoking status, and cataract surgery status showed that none of these factors were associated with retinal pigment epithelium mitochondrial DNA lesion frequency. Conclusions In this study of human donor eyes, neither retinal pigment epithelium mitochondrial DNA damage nor the stage of AMD severity are independently associated with cataract surgery after adjusting for other AMD risk factors. These new pathologic and molecular findings provide evidence against a relationship between cataract surgery and AMD progression and support the idea that cataract surgery is safe in the setting of AMD.
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Affiliation(s)
- Karen R. Armbrust
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Pabalu P. Karunadharma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Marcia R. Terluk
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Rebecca J. Kapphahn
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Timothy W. Olsen
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
- * E-mail:
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Bilbao-Malavé V, González-Zamora J, de la Puente M, Recalde S, Fernandez-Robredo P, Hernandez M, Layana AG, Saenz de Viteri M. Mitochondrial Dysfunction and Endoplasmic Reticulum Stress in Age Related Macular Degeneration, Role in Pathophysiology, and Possible New Therapeutic Strategies. Antioxidants (Basel) 2021; 10:antiox10081170. [PMID: 34439418 PMCID: PMC8388889 DOI: 10.3390/antiox10081170] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/14/2021] [Accepted: 07/20/2021] [Indexed: 02/07/2023] Open
Abstract
Age related macular degeneration (AMD) is the main cause of legal blindness in developed countries. It is a multifactorial disease in which a combination of genetic and environmental factors contributes to increased risk of developing this vision-incapacitating condition. Oxidative stress plays a central role in the pathophysiology of AMD and recent publications have highlighted the importance of mitochondrial dysfunction and endoplasmic reticulum stress in this disease. Although treatment with vascular endothelium growth factor inhibitors have decreased the risk of blindness in patients with the exudative form of AMD, the search for new therapeutic options continues to prevent the loss of photoreceptors and retinal pigment epithelium cells, characteristic of late stage AMD. In this review, we explain how mitochondrial dysfunction and endoplasmic reticulum stress participate in AMD pathogenesis. We also discuss a role of several antioxidants (bile acids, resveratrol, melatonin, humanin, and coenzyme Q10) in amelioration of AMD pathology.
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Affiliation(s)
- Valentina Bilbao-Malavé
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
| | - Jorge González-Zamora
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
| | - Miriam de la Puente
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
| | - Sergio Recalde
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Patricia Fernandez-Robredo
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - María Hernandez
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Alfredo Garcia Layana
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Manuel Saenz de Viteri
- Department of Opthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (V.B.-M.); (J.G.-Z.); (M.d.l.P.); (A.G.L.)
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Universidad de Navarra, 31008 Pamplona, Spain; (S.R.); (P.F.-R.); (M.H.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa en Salud: ‘Prevention, Early Detection, and Treatment of the Prevalent Degenerative and Chronic Ocular Pathology’ from (RD16/0008/0011), Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-948-255-400
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Choudhury R, Bayatti N, Scharff R, Szula E, Tilakaratna V, Udsen MS, McHarg S, Askari JA, Humphries MJ, Bishop PN, Clark SJ. FHL-1 interacts with human RPE cells through the α5β1 integrin and confers protection against oxidative stress. Sci Rep 2021; 11:14175. [PMID: 34239032 PMCID: PMC8266909 DOI: 10.1038/s41598-021-93708-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 06/16/2021] [Indexed: 12/16/2022] Open
Abstract
Retinal pigment epithelial (RPE) cells that underlie the neurosensory retina are essential for the maintenance of photoreceptor cells and hence vision. Interactions between the RPE and their basement membrane, i.e. the inner layer of Bruch's membrane, are essential for RPE cell health and function, but the signals induced by Bruch's membrane engagement, and their contributions to RPE cell fate determination remain poorly defined. Here, we studied the functional role of the soluble complement regulator and component of Bruch's membrane, Factor H-like protein 1 (FHL-1). Human primary RPE cells adhered to FHL-1 in a manner that was eliminated by either mutagenesis of the integrin-binding RGD motif in FHL-1 or by using competing antibodies directed against the α5 and β1 integrin subunits. These short-term experiments reveal an immediate protein-integrin interaction that were obtained from primary RPE cells and replicated using the hTERT-RPE1 cell line. Separate, longer term experiments utilising RNAseq analysis of hTERT-RPE1 cells bound to FHL-1, showed an increased expression of the heat-shock protein genes HSPA6, CRYAB, HSPA1A and HSPA1B when compared to cells bound to fibronectin (FN) or laminin (LA). Pathway analysis implicated changes in EIF2 signalling, the unfolded protein response, and mineralocorticoid receptor signalling as putative pathways. Subsequent cell survival assays using H2O2 to induce oxidative stress-induced cell death suggest hTERT-RPE1 cells had significantly greater protection when bound to FHL-1 or LA compared to plastic or FN. These data show a non-canonical role of FHL-1 in protecting RPE cells against oxidative stress and identifies a novel interaction that has implications for ocular diseases such as age-related macular degeneration.
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Affiliation(s)
- Rawshan Choudhury
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Nadhim Bayatti
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Richard Scharff
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Ewa Szula
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Viranga Tilakaratna
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Maja Søberg Udsen
- Panum Institute, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Selina McHarg
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
| | - Janet A Askari
- Wellcome Centre for Cell-Matrix Research, Division of Cell Matrix Biology & Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Oxford, UK
| | - Martin J Humphries
- Wellcome Centre for Cell-Matrix Research, Division of Cell Matrix Biology & Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Oxford, UK
| | - Paul N Bishop
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Simon J Clark
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK.
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Oxford, UK.
- Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Elfriede-Aulhorn-Straße 7, 72076, Tübingen, Germany.
- University Eye Clinic, Department for Ophthalmology, University of Tübingen, Tübingen, Germany.
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20
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Blasiak J, Szczepanska J, Fila M, Pawlowska E, Kaarniranta K. Potential of Telomerase in Age-Related Macular Degeneration-Involvement of Senescence, DNA Damage Response and Autophagy and a Key Role of PGC-1α. Int J Mol Sci 2021; 22:ijms22137194. [PMID: 34281248 PMCID: PMC8268995 DOI: 10.3390/ijms22137194] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023] Open
Abstract
Age-related macular degeneration (AMD), the main cause of vision loss in the elderly, is associated with oxidation in the retina cells promoting telomere attrition. Activation of telomerase was reported to improve macular functions in AMD patients. The catalytic subunit of human telomerase (hTERT) may directly interact with proteins important for senescence, DNA damage response, and autophagy, which are impaired in AMD. hTERT interaction with mTORC1 (mTOR (mechanistic target of rapamycin) complex 1) and PINK1 (PTEN-induced kinase 1) activates macroautophagy and mitophagy, respectively, and removes cellular debris accumulated over AMD progression. Ectopic expression of telomerase in retinal pigment epithelium (RPE) cells lengthened telomeres, reduced senescence, and extended their lifespan. These effects provide evidence for the potential of telomerase in AMD therapy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be involved in AMD pathogenesis through decreasing oxidative stress and senescence, regulation of vascular endothelial growth factor (VEGF), and improving autophagy. PGC-1α and TERT form an inhibitory positive feedback loop. In conclusion, telomerase activation and its ectopic expression in RPE cells, as well as controlled clinical trials on the effects of telomerase activation in AMD patients, are justified and should be assisted by PGC-1α modulators to increase the therapeutic potential of telomerase in AMD.
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Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
- Correspondence: (J.B.); (K.K.)
| | - Joanna Szczepanska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-216 Lodz, Poland;
| | - Michal Fila
- Department of Developmental Neurology and Epileptology, Polish Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland;
| | - Elzbieta Pawlowska
- Department of Orthodontics, Medical University of Lodz, 92-217 Lodz, Poland;
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, 70210 Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, 70210 Kuopio, Finland
- Correspondence: (J.B.); (K.K.)
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21
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La Cunza N, Tan LX, Thamban T, Germer CJ, Rathnasamy G, Toops KA, Lakkaraju A. Mitochondria-dependent phase separation of disease-relevant proteins drives pathological features of age-related macular degeneration. JCI Insight 2021; 6:142254. [PMID: 33822768 PMCID: PMC8262309 DOI: 10.1172/jci.insight.142254] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/31/2021] [Indexed: 01/21/2023] Open
Abstract
Age-related macular degeneration (AMD) damages the retinal pigment epithelium (RPE), the tissue that safeguards photoreceptor health, leading to irreversible vision loss. Polymorphisms in cholesterol and complement genes are implicated in AMD, yet mechanisms linking risk variants to RPE injury remain unclear. We sought to determine how allelic variants in the apolipoprotein E cholesterol transporter modulate RPE homeostasis and function. Using live-cell imaging, we show that inefficient cholesterol transport by the AMD risk-associated ApoE2 increases RPE ceramide, leading to autophagic defects and complement-mediated mitochondrial damage. Mitochondrial injury drives redox state–sensitive cysteine-mediated phase separation of ApoE2, forming biomolecular condensates that could nucleate drusen. The protective ApoE4 isoform lacks these cysteines and is resistant to phase separation and condensate formation. In Abca–/– Stargardt macular degeneration mice, mitochondrial dysfunction induces liquid-liquid phase separation of p62/SQSTM1, a multifunctional protein that regulates autophagy. Drugs that decrease RPE cholesterol or ceramide prevent mitochondrial injury and phase separation in vitro and in vivo. In AMD donor RPE, mitochondrial fragmentation correlates with ApoE and p62 condensates. Our studies demonstrate that major AMD genetic and biological risk pathways converge upon RPE mitochondria, and identify mitochondrial stress-mediated protein phase separation as an important pathogenic mechanism and promising therapeutic target in AMD.
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Affiliation(s)
- Nilsa La Cunza
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA
| | - Li Xuan Tan
- Department of Ophthalmology, School of Medicine, and
| | | | - Colin J Germer
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA
| | | | - Kimberly A Toops
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA.,Department of Anatomy, School of Medicine, University of California, San Francisco, California, USA
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22
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Oh JK, Lima de Carvalho JR, Nuzbrokh Y, Ryu J, Chemudupati T, Mahajan VB, Sparrow JR, Tsang SH. Retinal Manifestations of Mitochondrial Oxidative Phosphorylation Disorders. Invest Ophthalmol Vis Sci 2021; 61:12. [PMID: 33049060 PMCID: PMC7571321 DOI: 10.1167/iovs.61.12.12] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose The purpose of this paper was to discuss manifestations of primary mitochondrial dysfunctions and whether the retinal pigment epithelium or the photoreceptors are preferentially affected. Methods A retrospective analysis was performed of patients with clinically and laboratory confirmed diagnoses of maternally inherited diabetes and deafness (MIDD) or Kearns–Sayre syndrome (KSS). Patients underwent full ophthalmic examination, full-field electroretinogram, and multimodal imaging studies, including short-wavelength autofluorescence, spectral domain-optical coherence tomography, and color fundus photography. Results A total of five patients with MIDD and four patients with KSS were evaluated at two tertiary referral centers. Mean age at initial evaluation was 50.3 years old. Nascent outer retinal tubulations corresponding with faint foci of autofluorescence were observed in two patients with MIDD. Characteristic features of this cohort included a foveal sparing phenotype observed in 13 of 18 eyes (72%), global absence of intraretinal pigment migration, and preserved retinal function on full-field electroretinogram testing in 12 of 16 eyes (75%). One patient diagnosed with MIDD presented with an unusual pattern of atrophy surrounding the parapapillary region and one patient with KSS presented with an atypical choroideremia-like phenotype. Conclusions MIDD and KSS are phenotypically heterogeneous disorders. Several features of disease suggest that primary mitochondrial dysfunction may first affect the retinal pigment epithelium followed by secondary photoreceptor loss. Similarities between primary mitochondrial degenerations and retinal disorders, such as age-related macular degeneration may suggest a primary role of mitochondria in the pathogenesis of these oligogenic disorders.
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Affiliation(s)
- Jin Kyun Oh
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,State University of New York at Downstate Medical Center, Brooklyn, New York, United States
| | - Jose Ronaldo Lima de Carvalho
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Department of Ophthalmology, Empresa Brasileira de Servicos Hospitalares (EBSERH) - Hospital das Clinicas de Pernambuco (HCPE), Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil.,Department of Ophthalmology, Federal University of São Paulo (UNIFESP), São Paulo, São Paulo, Brazil
| | - Yan Nuzbrokh
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Renaissance School of Medicine at Stony Brook University, Stony Brook, New York, United States
| | - Joseph Ryu
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States
| | - Teja Chemudupati
- Molecular Surgery Laboratory, Byers Eye Institute, Stanford University, Palo Alto, California, United States
| | - Vinit B Mahajan
- Molecular Surgery Laboratory, Byers Eye Institute, Stanford University, Palo Alto, California, United States.,Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States
| | - Janet R Sparrow
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Department of Pathology and Cell Biology and Columbia Stem Cell Initiative (CSCI), Columbia University Irving Medical Center, New York, New York, United States
| | - Stephen H Tsang
- Jonas Children's Vision Care, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York, United States.,Department of Pathology and Cell Biology and Columbia Stem Cell Initiative (CSCI), Columbia University Irving Medical Center, New York, New York, United States
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23
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Armento A, Ueffing M, Clark SJ. The complement system in age-related macular degeneration. Cell Mol Life Sci 2021; 78:4487-4505. [PMID: 33751148 PMCID: PMC8195907 DOI: 10.1007/s00018-021-03796-9] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/05/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022]
Abstract
Age-related macular degeneration (AMD) is a chronic and progressive degenerative disease of the retina, which culminates in blindness and affects mainly the elderly population. AMD pathogenesis and pathophysiology are incredibly complex due to the structural and cellular complexity of the retina, and the variety of risk factors and molecular mechanisms that contribute to disease onset and progression. AMD is driven by a combination of genetic predisposition, natural ageing changes and lifestyle factors, such as smoking or nutritional intake. The mechanism by which these risk factors interact and converge towards AMD are not fully understood and therefore drug discovery is challenging, where no therapeutic attempt has been fully effective thus far. Genetic and molecular studies have identified the complement system as an important player in AMD. Indeed, many of the genetic risk variants cluster in genes of the alternative pathway of the complement system and complement activation products are elevated in AMD patients. Nevertheless, attempts in treating AMD via complement regulators have not yet been successful, suggesting a level of complexity that could not be predicted only from a genetic point of view. In this review, we will explore the role of complement system in AMD development and in the main molecular and cellular features of AMD, including complement activation itself, inflammation, ECM stability, energy metabolism and oxidative stress.
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Affiliation(s)
- Angela Armento
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.
| | - Simon J Clark
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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24
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Ebeling MC, Geng Z, Kapphahn RJ, Roehrich H, Montezuma SR, Dutton JR, Ferrington DA. Impaired Mitochondrial Function in iPSC-Retinal Pigment Epithelium with the Complement Factor H Polymorphism for Age-Related Macular Degeneration. Cells 2021; 10:cells10040789. [PMID: 33918210 PMCID: PMC8066149 DOI: 10.3390/cells10040789] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 12/27/2022] Open
Abstract
Age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, is characterized by loss of the retinal pigment epithelium (RPE). While the disease mechanism remains unclear, prior studies have linked AMD with RPE mitochondrial defects and genetic polymorphisms in the complement pathway. This study used RPE generated from induced pluripotent stem cells (iPSC-RPE), which were derived from human donors with or without AMD and genotyped for the complement factor H (CFH) AMD high-risk allele (rs1061170, Y402H) to investigate whether donor disease state or genotype had a detrimental effect on mitochondrial function and inflammation. Results show that cells derived from donors with AMD display decreased mitochondrial function under conditions of stress and elevated expression of inflammatory markers compared to iPSC-RPE from individuals without AMD. A more pronounced reduction in mitochondrial function and increased inflammatory markers was observed in CFH high-risk cells, irrespective of disease state. These results provide evidence for a previously unrecognized link between CFH and mitochondrial function that could contribute to RPE loss in AMD patients harboring the CFH high-risk genotype.
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Affiliation(s)
- Mara C. Ebeling
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - Zhaohui Geng
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rebecca J. Kapphahn
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - Heidi Roehrich
- Histology Core for Vision Research, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - James R. Dutton
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
- Correspondence: (J.R.D.); (D.A.F.); Tel.: +1-612-626-2762 (J.R.D.); +1-612-624-8267 (D.A.F.)
| | - Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Correspondence: (J.R.D.); (D.A.F.); Tel.: +1-612-626-2762 (J.R.D.); +1-612-624-8267 (D.A.F.)
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25
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Nicholson C, Ishii M, Annamalai B, Chandler K, Chwa M, Kenney MC, Shah N, Rohrer B. J or H mtDNA haplogroups in retinal pigment epithelial cells: Effects on cell physiology, cargo in extracellular vesicles, and differential uptake of such vesicles by naïve recipient cells. Biochim Biophys Acta Gen Subj 2021; 1865:129798. [PMID: 33217521 PMCID: PMC8396072 DOI: 10.1016/j.bbagen.2020.129798] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 01/11/2023]
Abstract
PURPOSE Extracellular vesicles (EVs) are predicted to represent the internal state of cells. In polarized RPE monolayers, EVs can mediate long-distance communication, requiring endocytosis via protein-protein interactions. EV uptake from oxidatively stressed donor cells triggers loss in transepithelial resistance (TER) in recipient monolayers mediated by HDAC6. Here, we examine EVs released from RPE cells with identical nuclear genes but different mitochondrial (mt)DNA haplogroups (H, J). J-cybrids produce less ATP, and the J-haplogroup is associated with a higher risk for age-related macular degeneration. METHODS Cells were grown as mature monolayers to either collect EVs from apical surfaces or to serve as naïve recipient cells. Transfer assays, transferring EVs to a recipient monolayer were performed, monitoring TER and EV-uptake. The presence of known EV surface proteins was quantified by protein chemistry. RESULTS H- and J-cybrids were confirmed to exhibit different levels of TER and energy metabolism. EVs from J-cybrids reduced TER in recipient ARPE-19 cells, whereas EVs from H-cybrids were ineffective. TER reduction was mediated by HDAC6 activity, and EV uptake required interaction between integrin and its ligands and surface proteoglycans. Protein quantifications confirmed elevated levels of fibronectin and annexin A2 on J-cybrid EVs. CONCLUSIONS We speculate that RPE EVs have a finite set of ligands (membrane proteoglycans and integrins and/or annexin A2) that are elevated in EVs from stressed cells; and that if EVs released by the RPE could be captured from serum, that they might provide a disease biomarker of RPE-dependent diseases.
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Affiliation(s)
- Crystal Nicholson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Masaaki Ishii
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Balasubramaniam Annamalai
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Kyrie Chandler
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, United States of America
| | - M Cristina Kenney
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, United States of America
| | - Navjot Shah
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America; Department of Neurosciences Medical University of South Carolina, Charleston, SC 29425, United States of America; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States of America.
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26
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Homma K, Toda E, Osada H, Nagai N, Era T, Tsubota K, Okano H, Ozawa Y. Taurine rescues mitochondria-related metabolic impairments in the patient-derived induced pluripotent stem cells and epithelial-mesenchymal transition in the retinal pigment epithelium. Redox Biol 2021; 41:101921. [PMID: 33706170 PMCID: PMC7944050 DOI: 10.1016/j.redox.2021.101921] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/16/2021] [Accepted: 02/23/2021] [Indexed: 12/14/2022] Open
Abstract
Mitochondria participate in various metabolic pathways, and their dysregulation results in multiple disorders, including aging-related diseases. However, the metabolic changes and mechanisms of mitochondrial disorders are not fully understood. Here, we found that induced pluripotent stem cells (iPSCs) from a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) showed attenuated proliferation and survival when glycolysis was inhibited. These deficits were rescued by taurine administration. Metabolomic analyses showed that the ratio of the reduced (GSH) to oxidized glutathione (GSSG) was decreased; whereas the levels of cysteine, a substrate of GSH, and oxidative stress markers were upregulated in MELAS iPSCs. Taurine normalized these changes, suggesting that MELAS iPSCs were affected by the oxidative stress and taurine reduced its influence. We also analyzed the retinal pigment epithelium (RPE) differentiated from MELAS iPSCs by using a three-dimensional culture system and found that it showed epithelial mesenchymal transition (EMT), which was suppressed by taurine. Therefore, mitochondrial dysfunction caused metabolic changes, accumulation of oxidative stress that depleted GSH, and EMT in the RPE that could be involved in retinal pathogenesis. Because all these phenomena were sensitive to taurine treatment, we conclude that administration of taurine may be a potential new therapeutic approach for mitochondria-related retinal diseases. iPS cell lines were derived from a MELAS patient with the mtDNA A3243G mutation. Decreased proliferation and survival of MELAS iPSCs were rescued by taurine. Reduction in GSH/GSSG ratio in MELAS iPSCs was suppressed by taurine. EMT in MELAS iPSC-derived retinal pigment epithelium was suppressed by taurine. Oxidative stress markers in MELAS iPSCs and RPE were suppressed by taurine.
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Affiliation(s)
- Kohei Homma
- Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan
| | - Eriko Toda
- Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan
| | - Hideto Osada
- Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan
| | - Norihiro Nagai
- Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan
| | - Takumi Era
- Department of Cell Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, Chuo-ku, Kumamoto, 860-0811, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan
| | - Yoko Ozawa
- Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan; Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo, 160-8582, Japan; Department of Ophthalmology, St. Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo, 104-8560, Japan; St. Luke's International University, 9-1 Akashi-cho, Chuo-ku, Tokyo, 104-8560, Japan.
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27
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Atilano SR, Udar N, Satalich TA, Udar V, Chwa M, Kenney MC. Low frequency mitochondrial DNA heteroplasmy SNPs in blood, retina, and [RPE+choroid] of age-related macular degeneration subjects. PLoS One 2021; 16:e0246114. [PMID: 33513185 PMCID: PMC7846006 DOI: 10.1371/journal.pone.0246114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 01/13/2021] [Indexed: 01/07/2023] Open
Abstract
Purpose Mitochondrial (mt) DNA damage is associated with age-related macular degeneration (AMD) and other human aging diseases. This study was designed to quantify and characterize mtDNA low-frequency heteroplasmy single nucleotide polymorphisms (SNPs) of three different tissues isolated from AMD subjects using Next Generation Sequencing (NGS) technology. Methods DNA was extracted from neural retina, [RPE+choroid] and blood from three deceased age-related macular degeneration (AMD) subjects. Entire mitochondrial genomes were analyzed for low-frequency heteroplasmy SNPs using NGS technology that independently sequenced both mtDNA strands. This deep sequencing method (average sequencing depth of 30,000; range 1,000–100,000) can accurately differentiate low-frequency heteroplasmy SNPs from DNA modification artifacts. Twenty-three ‘hot-spot’ heteroplasmy mtDNA SNPs were analyzed in 222 additional blood samples. Results Germline homoplasmy SNPs that defined mtDNA haplogroups were consistent in the three tissues of each subject. Analyses of SNPs with <40% heteroplasmy revealed the blood had significantly greater numbers of heteroplasmy SNPs than retina alone (p≤0.05) or retina+choroid combined (p = 0.008). Twenty-three ‘hot-spot’ mtDNA heteroplasmy SNPs were present, with three being non-synonymous (amino acid change). Four ‘hot-spot’ heteroplasmy SNPs (m.1120C>T, m.1284T>C, m.1556C>T, m.7256C>T) were found in additional samples (n = 222). Five heteroplasmy SNPs (m.4104A>G, m.5320C>T, m.5471G>A, m.5474A>G, m.5498A>G) declined with age. Two heteroplasmy SNPs (m.13095T>C, m.13105A>G) increased in AMD compared to Normal samples. In the heteroplasmy SNPs, very few transversion mutations (purine to pyrimidine or vice versa, associated with oxidative damage) were found and the majority were transition changes (purine to purine or pyrimidine to pyrimidine, associated with replication errors). Conclusion Within an individual, the blood, retina and [RPE+choroid] contained identical homoplasmy SNPs representing inherited germline mtDNA haplogroup. NGS methodology showed significantly more mtDNA heteroplasmy SNPs in blood compared to retina and [RPE+choroid], suggesting the latter tissues have substantial protection. Significantly higher heteroplasmy levels of m.13095T>C and m.13105A>G may represent potential AMD biomarkers. Finally, high levels of transition mutations suggest that accumulation of heteroplasmic SNPs may occur through replication errors rather than oxidative damage.
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Affiliation(s)
- Shari R. Atilano
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Nitin Udar
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Timothy A. Satalich
- Institute for Mathematical Behavioral Science, University of California Irvine, Irvine, CA, United States of America
| | - Viraat Udar
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - M. Cristina Kenney
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, United States of America
- * E-mail:
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28
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Ruan Y, Jiang S, Gericke A. Age-Related Macular Degeneration: Role of Oxidative Stress and Blood Vessels. Int J Mol Sci 2021; 22:ijms22031296. [PMID: 33525498 PMCID: PMC7866075 DOI: 10.3390/ijms22031296] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is a common irreversible ocular disease characterized by vision impairment among older people. Many risk factors are related to AMD and interact with each other in its pathogenesis. Notably, oxidative stress and choroidal vascular dysfunction were suggested to be critically involved in AMD pathogenesis. In this review, we give an overview on the factors contributing to the pathophysiology of this multifactorial disease and discuss the role of reactive oxygen species and vascular function in more detail. Moreover, we give an overview on therapeutic strategies for patients suffering from AMD.
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Affiliation(s)
- Yue Ruan
- Correspondence: (Y.R.); (A.G.); Tel.: +49-6131-178-276 (Y.R. & A.G.)
| | | | - Adrian Gericke
- Correspondence: (Y.R.); (A.G.); Tel.: +49-6131-178-276 (Y.R. & A.G.)
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Tzoumas N, Hallam D, Harris CL, Lako M, Kavanagh D, Steel DHW. Revisiting the role of factor H in age-related macular degeneration: Insights from complement-mediated renal disease and rare genetic variants. Surv Ophthalmol 2020; 66:378-401. [PMID: 33157112 DOI: 10.1016/j.survophthal.2020.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 12/14/2022]
Abstract
Ophthalmologists are long familiar with the eye showing signs of systemic disease, but the association between age-related macular degeneration and abnormal complement activation, common to several renal disorders, has only recently been elucidated. Although complement activation products were identified in drusen almost three decades ago, it was not until the early 21st century that a single-nucleotide polymorphism in the complement factor H gene was identified as a major heritable determinant of age-related macular degeneration, galvanizing global efforts to unravel the pathogenesis of this common disease. Advances in proteomic analyses and familial aggregation studies have revealed distinctive clinical phenotypes segregated by the functional effects of common and rare genetic variants on the mature protein and its splice variant, factor H-like protein 1. The predominance of loss-of-function, N-terminal mutations implicate age-related macular degeneration as a disease of general complement dysregulation, offering several therapeutic avenues for its modulation. Here, we explore the molecular impact of these mutations/polymorphisms on the ability of variant factor H/factor H-like protein 1 to localize to polyanions, pentraxins, proinflammatory triggers, and cell surfaces across ocular and renal tissues and exert its multimodal regulatory functions and their clinical implications. Finally, we critically evaluate key therapeutic and diagnostic efforts in this rapidly evolving field.
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Affiliation(s)
- Nikolaos Tzoumas
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
| | - Dean Hallam
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Claire L Harris
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom; National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Majlinda Lako
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - David Kavanagh
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom; National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - David H W Steel
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom; Sunderland Eye Infirmary, Sunderland, United Kingdom
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Kaarniranta K, Uusitalo H, Blasiak J, Felszeghy S, Kannan R, Kauppinen A, Salminen A, Sinha D, Ferrington D. Mechanisms of mitochondrial dysfunction and their impact on age-related macular degeneration. Prog Retin Eye Res 2020; 79:100858. [PMID: 32298788 PMCID: PMC7650008 DOI: 10.1016/j.preteyeres.2020.100858] [Citation(s) in RCA: 220] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/21/2022]
Abstract
Oxidative stress-induced damage to the retinal pigment epithelium (RPE) is considered to be a key factor in age-related macular degeneration (AMD) pathology. RPE cells are constantly exposed to oxidative stress that may lead to the accumulation of damaged cellular proteins, lipids, nucleic acids, and cellular organelles, including mitochondria. The ubiquitin-proteasome and the lysosomal/autophagy pathways are the two major proteolytic systems to remove damaged proteins and organelles. There is increasing evidence that proteostasis is disturbed in RPE as evidenced by lysosomal lipofuscin and extracellular drusen accumulation in AMD. Nuclear factor-erythroid 2-related factor-2 (NFE2L2) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) are master transcription factors in the regulation of antioxidant enzymes, clearance systems, and biogenesis of mitochondria. The precise cause of RPE degeneration and the onset and progression of AMD are not fully understood. However, mitochondria dysfunction, increased reactive oxygen species (ROS) production, and mitochondrial DNA (mtDNA) damage are observed together with increased protein aggregation and inflammation in AMD. In contrast, functional mitochondria prevent RPE cells damage and suppress inflammation. Here, we will discuss the role of mitochondria in RPE degeneration and AMD pathology focused on mtDNA damage and repair, autophagy/mitophagy signaling, and regulation of inflammation. Mitochondria are putative therapeutic targets to prevent or treat AMD.
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Affiliation(s)
- Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland and Kuopio University Hospital, P.O. Box 1627, FI-70211, Kuopio, Finland.
| | - Hannu Uusitalo
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland and Tays Eye Centre, Tampere University Hospital, P.O.Box 2000, 33521 Tampere, Finland
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236, Lodz, Poland
| | - Szabolcs Felszeghy
- Department of Biomedicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Ram Kannan
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, 1355 San Pablo St, Los Angeles, CA, 90033, USA
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Debasish Sinha
- Glia Research Laboratory, Department of Ophthalmology, University of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA, PA 15224, USA; Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Room M035 Robert and Clarice Smith Bldg, 400 N Broadway, Baltimore, MD, 21287, USA
| | - Deborah Ferrington
- Department of Ophthalmology and Visual Neurosciences, 2001 6th St SE, University of Minnesota, Minneapolis, MN 55455, USA
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Tan LX, Germer CJ, La Cunza N, Lakkaraju A. Complement activation, lipid metabolism, and mitochondrial injury: Converging pathways in age-related macular degeneration. Redox Biol 2020; 37:101781. [PMID: 33162377 PMCID: PMC7767764 DOI: 10.1016/j.redox.2020.101781] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/22/2020] [Accepted: 10/29/2020] [Indexed: 02/07/2023] Open
Abstract
The retinal pigment epithelium (RPE) is the primary site of injury in non-neovascular age-related macular degeneration or dry AMD. Polymorphisms in genes that regulate complement activation and cholesterol metabolism are strongly associated with AMD, but the biology underlying disease-associated variants is not well understood. Here, we highlight recent studies that have used molecular, biochemical, and live-cell imaging methods to elucidate mechanisms by which aging-associated insults conspire with AMD genetic risk variants to tip the balance towards disease. We discuss how critical functions including lipid metabolism, autophagy, complement regulation, and mitochondrial dynamics are compromised in the RPE, and how a deeper understanding of these mechanisms has helped identify promising therapeutic targets to preserve RPE homeostasis in AMD.
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Affiliation(s)
- Li Xuan Tan
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA
| | - Colin J Germer
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, USA
| | - Nilsa La Cunza
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, USA
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, USA; Department of Anatomy, School of Medicine, University of California, San Francisco, CA, USA.
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Bird A. Role of retinal pigment epithelium in age-related macular disease: a systematic review. Br J Ophthalmol 2020; 105:1469-1474. [PMID: 32950958 DOI: 10.1136/bjophthalmol-2020-317447] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/27/2020] [Accepted: 09/04/2020] [Indexed: 02/07/2023]
Abstract
Age-related macular disease (AMD) is a major cause of blindness and there is little treatment currently available by which the progress of the basic disorder can be modulated. Histological and clinical studies show that the major tissues involved are the outer retina, retinal pigment epithelium, Bruch's membrane and choroid. Because of a wide variation of phenotype from one case to another, it has been suggested that accurate phenotyping would be necessary for assessment of the effectiveness of treatment that is tissue-directed. However, based on findings from the study of human donor material and animal models of disease and of cell culture, it is concluded that retinal pigment epithelial dysfunction plays a central role in the disease process in most, if not all, cases of early AMD. The metabolism of phagosomal material, particularly lipids, and energy generation are interdependent, and dysfunction of both appears to be important in the genesis of disease. Evidence exists to suggest that both can be modulated therapeutically. These metabolic functions are amenable to further investigation in both the normal state and in disease. Once fully characterised, it is likely that treatment could be directed towards a limited number of functions in single tissue, thus simplifying treatment strategies.
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Affiliation(s)
- Alan Bird
- Genetics, Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Sreekumar PG, Kannan R. Mechanisms of protection of retinal pigment epithelial cells from oxidant injury by humanin and other mitochondrial-derived peptides: Implications for age-related macular degeneration. Redox Biol 2020; 37:101663. [PMID: 32768357 PMCID: PMC7767738 DOI: 10.1016/j.redox.2020.101663] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/18/2020] [Accepted: 07/26/2020] [Indexed: 02/06/2023] Open
Abstract
The mitochondrial-derived peptides (MDPs) are a new class of small open reading frame encoded polypeptides with pleiotropic properties. The prominent members are Humanin (HN) and small HN-like peptide (SHLP) 2, which encode 16S rRNA, while mitochondrial open reading frame of the twelve S c (MOTS-c) encodes 12S rRNA of the mitochondrial genome. While the multifunctional properties of HN and its analog 14-HNG have been well documented, their protective role in the retinal pigment epithelium (RPE)/retina has been investigated only recently. In this review, we have summarized the multiple effects of HN and its analogs, SHLP2 and MOTS-c in oxidatively stressed human RPE and the regulatory pathways of signaling, mitochondrial function, senescence, and inter-organelle crosstalk. Emphasis is given to the mitochondrial functions such as biogenesis, bioenergetics, and autophagy in RPE undergoing oxidative stress. Further, the potential use of HN and its analogs in the prevention of age-related macular degeneration (AMD) are also presented. In addition, the role of novel, long-acting HN elastin-like polypeptides in nanotherapy of AMD and other ocular diseases stemming from oxidative damage is discussed. It is expected MDPs will become a promising group of mitochondrial peptides with valuable therapeutic applications in the treatment of retinal diseases.
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Affiliation(s)
- Parameswaran G Sreekumar
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, CA, 90033, USA
| | - Ram Kannan
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, CA, 90033, USA; Stein Eye Institute, Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA.
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Kaarniranta K, Pawlowska E, Szczepanska J, Blasiak J. DICER1 in the Pathogenesis of Age-related Macular Degeneration (AMD) - Alu RNA Accumulation versus miRNA Dysregulation. Aging Dis 2020; 11:851-862. [PMID: 32765950 PMCID: PMC7390522 DOI: 10.14336/ad.2019.0809] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 08/09/2019] [Indexed: 12/11/2022] Open
Abstract
DICER1 deficiency in the retinal pigment epithelium (RPE) was associated with the accumulation of Alu transcripts and implicated in geographic atrophy (GA), a form of age-related macular degeneration (AMD), an eye disease leading to blindness in millions of people. Although the exact mechanism of this association is not fully known, the activation of the NLRP3 inflammasome, maturation of caspase-1 and disruption in mitochondrial homeostasis in RPE cells were shown as critical for it. DICER1 deficiency results in dysregulation of miRNAs and changes in the expression of many genes important for RPE homeostasis, which may also contribute to AMD. DICER1 deficiency can change the functions of the miR-183/96/182 cluster that regulates photoreceptors and their synaptic transmission. Aging, the main AMD risk factor, is associated with decreased expression of DICER1 and changes in its diurnal pattern that are not synchronized with circadian regulation in the retina. The initial insult inducing DICER1 deficiency in AMD may be oxidative stress, another major risk factor of AMD, but further studies on the role of deficient DICER1 in AMD pathogenesis and its therapeutic potential are needed.
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Affiliation(s)
- Kai Kaarniranta
- 1Department of Ophthalmology, University of Eastern Finland, Kuopio 70211, Finland and Department of Ophthalmology, Kuopio University Hospital, Kuopio 70029, Finland
| | - Elzbieta Pawlowska
- 2Department of Orthodontics, Medical University of Lodz, 92-216 Lodz, Poland
| | - Joanna Szczepanska
- 3Department of Pediatric Dentistry, Medical University of Lodz, 92-216 Lodz, Poland
| | - Janusz Blasiak
- 4Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
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Loss of Complement Factor H impairs antioxidant capacity and energy metabolism of human RPE cells. Sci Rep 2020; 10:10320. [PMID: 32587311 PMCID: PMC7316856 DOI: 10.1038/s41598-020-67292-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/19/2020] [Indexed: 12/28/2022] Open
Abstract
Polymorphisms in the Complement Factor H (CFH) gene, coding for the Factor H protein (FH), can increase the risk for age-related macular degeneration (AMD). AMD-associated CFH risk variants, Y402H in particular, impair FH function leading to complement overactivation. Whether this alone suffices to trigger AMD pathogenesis remains unclear. In AMD, retinal homeostasis is compromised due to the dysfunction of retinal pigment epithelium (RPE) cells. To investigate the impact of endogenous FH loss on RPE cell balance, we silenced CFH in human hTERT-RPE1 cells. FH reduction led to accumulation of C3, at both RNA and protein level and increased RPE vulnerability toward oxidative stress. Mild hydrogen-peroxide exposure in combination with CFH knock-down led to a reduction of glycolysis and mitochondrial respiration, paralleled by an increase in lipid peroxidation, which is a key aspect of AMD pathogenesis. In parallel, cell viability was decreased. The perturbations of energy metabolism were accompanied by transcriptional deregulation of several glucose metabolism genes as well as genes modulating mitochondrial stability. Our data suggest that endogenously produced FH contributes to transcriptional and metabolic homeostasis and protects RPE cells from oxidative stress, highlighting a novel role of FH in AMD pathogenesis.
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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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Blasiak J. Senescence in the pathogenesis of age-related macular degeneration. Cell Mol Life Sci 2020; 77:789-805. [PMID: 31897543 PMCID: PMC11105088 DOI: 10.1007/s00018-019-03420-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 12/06/2019] [Accepted: 12/10/2019] [Indexed: 01/07/2023]
Abstract
Age-related macular degeneration (AMD) is a complex eye disease underlined by the death of photoreceptors and degeneration of retinal pigment epithelium (RPE) and choriocapillaris (CC). The mechanism(s) responsible for massive and progressive retinal degeneration is not completely known. Senescence, a state of permanent inhibition of cell growth, may be induced by many factors important for AMD pathogenesis and results in senescence-associated secretory phenotype (SASP) that releases growth factors, cytokines, chemokines, proteases and other molecules inducing inflammation and other AMD-related effects. These effects can be induced in the affected cell and neighboring cells, leading to progression of AMD phenotype. Senescent cells also release reactive oxygen species that increase SASP propagation. Many other pathways of senescence-related AMD pathogenesis, including autophagy, the cGAS-STING signaling, degeneration of CC by membrane attack complex, can be considered. A2E, a fluorophore present in lipofuscin, amyloid-beta peptide and humanin, a mitochondria-derived peptide, may link AMD with senescence. Further studies on senescence in AMD pathogenesis to check the possibility of opening a perspective of the use of drugs killing senescent cells (senolytics) and terminating SASP bystander effects (senostatics) might be beneficial for AMD that at present is an incurable disease.
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Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, Lodz, Poland.
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Pool FM, Kiel C, Serrano L, Luthert PJ. Repository of proposed pathways and protein-protein interaction networks in age-related macular degeneration. NPJ Aging Mech Dis 2020; 6:2. [PMID: 31934346 PMCID: PMC6946811 DOI: 10.1038/s41514-019-0039-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/18/2019] [Indexed: 12/21/2022] Open
Abstract
Age-related macular degeneration (AMD) is one of the commonest causes of sight loss in the elderly population and to date there is no intervention that slows or prevents early AMD disease progressing to blinding neovascularization or geographic atrophy. AMD is a complex disease and factors proposed to contribute to the development and progression of disease include aging, genetics, epigenetics, oxidative stress, pro-inflammatory state, and life-style factors such as smoking, alcohol, and high fat diet. Here, we generate a knowledge repository of pathways and protein–protein interaction (PPI) networks likely to be implicated in AMD pathogenesis, such as complement activation, lipid trafficking and metabolism, vitamin A cycle, oxidative stress, proteostasis, bioenergetics, autophagy/mitophagy, extracellular matrix (ECM) turnover, and choroidal vascular dropout. Two disctinct clusters ermerged from the networks for parainflamation and ECM homeostasis, which may represent two different disease modules underlying AMD pathology. Our analyses also suggest that the disease manifests primarily in RPE/choroid and less in neural retina. The use of standardized syntax when generating maps of these biological processes (SBGN standard) and networks (PSI standard) enables visualization of complex information in graphical programs such as CellDesigner and Cytoscape and enhances reusability and extension of data. The ability to focus onto subnetworks, multiple visualizations and simulation options will enable the AMD research community to computationally model subnetworks or to test experimentally new hypotheses arising from connectivities in the AMD pathway map.
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Affiliation(s)
- Fran M Pool
- 1UCL Institute of Ophthalmology, and NIHR Moorfields Biomedical Research Centre, University College London, 11-43 Bath Street, London, EC1V 9EL UK
| | - Christina Kiel
- 2Systems Biology Ireland & Charles Institute of Dermatology & School of Medicine, University College Dublin, Belfield Dublin, 4 Ireland
| | - Luis Serrano
- 3Centre for Genomic Regulation (CRG), Systems Biology Programme. The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, 08003 Spain.,4Universitat Pompeu Fabra (UPF), Barcelona, 08003 Spain.,5Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys 23, Barcelona, 08010 Spain
| | - Philip J Luthert
- 1UCL Institute of Ophthalmology, and NIHR Moorfields Biomedical Research Centre, University College London, 11-43 Bath Street, London, EC1V 9EL UK
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Nashine S, Subramaniam SR, Chwa M, Nesburn A, Kuppermann BD, Federoff H, Kenney MC. PU-91 drug rescues human age-related macular degeneration RPE cells; implications for AMD therapeutics. Aging (Albany NY) 2019; 11:6691-6713. [PMID: 31477635 PMCID: PMC6756897 DOI: 10.18632/aging.102179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/09/2019] [Indexed: 12/24/2022]
Abstract
Since mitochondrial dysfunction is implicated in the pathogenesis of AMD, this study is based on the premise that repurposing of mitochondria-stabilizing FDA-approved drugs such as PU-91, might rescue AMD RPE cells from AMD mitochondria-induced damage. The PU-91 drug upregulates PGC-1α which is a critical regulator of mitochondrial biogenesis. Herein, we tested the therapeutic potential of PU-91 drug and examined the additive effects of treatment with PU-91 and esterase inhibitors i.e., EI-12 and EI-78, using the in vitro transmitochondrial AMD cell model. This model was created by fusing platelets obtained from AMD patients with Rho0 i.e., mitochondria-deficient, ARPE-19 cell lines. The resulting AMD RPE cell lines have identical nuclei but differ in their mitochondrial DNA content, which is derived from individual AMD patients. Briefly, we report significant improvement in cell survival, mitochondrial health, and antioxidant potential in PU-91-treated AMD RPE cells compared to their untreated counterparts. In conclusion, this study identifies PU 91 as a therapeutic candidate drug for AMD and repurposing of PU-91 will be a smoother transition from lab bench to clinic since the pharmacological profiles of PU-91 have been examined already.
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Affiliation(s)
- Sonali Nashine
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA
| | | | - Marilyn Chwa
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA
| | - Anthony Nesburn
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA.,Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Baruch D Kuppermann
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA
| | - Howard Federoff
- Department of Neurology, University of California Irvine, Irvine, CA 92697, USA
| | - M Cristina Kenney
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA.,Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA 92697, USA
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Abstract
Mitochondria and mitochondrial DNA (mtDNA) variation are now recognized as important factors in the development of osteoarthritis (OA). Mitochondria are the energy powerhouses of the cell, and also regulate different processes involved in the pathogenesis of OA including inflammation, apoptosis, calcium metabolism and the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Mitochondria contain their own genetic material, mtDNA, which evolved through the sequential accumulation of mtDNA variants to enable humans to adapt to different climates. The ROS and reactive metabolic intermediates that are by-products of mitochondrial metabolism are regulated in part by mtDNA and are among the signals that transmit information between mitochondria and the nucleus. These signals can alter nuclear gene expression and, when disrupted, affect a number of cellular processes and metabolic pathways, leading to disease. mtDNA variation influences OA-associated phenotypes, including those related to metabolism, inflammation and even ageing, as well as nuclear epigenetic regulation. This influence also enables the use of specific mtDNA haplogroups as complementary diagnostic and prognostic biomarkers of OA.
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Efendieva MH, Budzinskaya MV, Kadyshev VV, Zinchenko RA, Savochkina OA, Pupysheva AD. [Molecular and genetic aspects of age-related macular degeneration and glaucoma]. Vestn Oftalmol 2019; 135:121-127. [PMID: 31393456 DOI: 10.17116/oftalma2019135031121] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In most cases, age-related macular degeneration (AMD) and glaucoma are considered multi-factor diseases that lead to irreversible blindness in senior population of developed countries. Among different types of these diseases, around 5% are monogenic. Studying their molecular and genetic aspects can lay the basis for improvement of diagnostic methods, prognosis of the risks of development, manner of progression and treatment outcomes, as well as creation of new therapy methods. The article reviews modern understanding of the etiopathogenesis of AMD and glaucoma and describes their interrelations.
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Affiliation(s)
- M H Efendieva
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - M V Budzinskaya
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - V V Kadyshev
- Research Centre for Medical Genetics, 1 Moskvorechie St., Moscow, Russian Federation, 115478
| | - R A Zinchenko
- Research Centre for Medical Genetics, 1 Moskvorechie St., Moscow, Russian Federation, 115478; Pirogov Russian National Research Medical University, 1 Ostrovitianov St., Moscow, Russian Federation, 117997
| | - O A Savochkina
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - A D Pupysheva
- I.M. Sechenov First Moscow State Medical University, Department of Ophthalmology, 8-2 Trubetskaya St., Moscow, Russian Federation, 119991
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Nashine S, Nesburn AB, Kuppermann BD, Kenney MC. Age-related macular degeneration (AMD) mitochondria modulate epigenetic mechanisms in retinal pigment epithelial cells. Exp Eye Res 2019; 189:107701. [PMID: 31226340 DOI: 10.1016/j.exer.2019.107701] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 06/07/2019] [Accepted: 06/12/2019] [Indexed: 02/06/2023]
Abstract
Mitochondrial damage and epigenetic modifications have been implicated in the pathogenesis of Age-related Macular Degeneration (AMD). This study was designed to investigate the effects of AMD/normal mitochondria on epigenetic regulation in human transmitochondrial retinal pigment epithelial (RPE) cells in vitro. Human RPE cybrid cell lines were created by fusing mitochondria-deficient (Rho0) ARPE-19 cells with platelets obtained from either AMD patients (AMD cybrids) or normal subjects (normal cybrids). Therefore, all cybrids had identical nuclei (derived from ARPE-19 cells) but mitochondria derived from either AMD patients or age-matched normal subjects. AMD cybrids demonstrated increased RNA/protein levels for five methylation-related and four acetylation-related genes, along with lower levels of two methylation and three acetylation genes compared to normal cybrids. Demethylation using 5-Aza-2'-deoxycytidine (DAC) led to decreased expression of VEGF-A gene in AMD cells. Trichostatin A (TSA), an HDAC inhibitor, also influenced protein levels of VEGF-A, HIF1α, NFκB, and CFH in AMD cells. Our findings suggest that retrograde signaling leads to mitochondria-nucleus interactions that influence the epigenetic status of the RPE cells and this may help in the identification of future potential therapeutic targets for AMD.
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Affiliation(s)
- Sonali Nashine
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA
| | - Anthony B Nesburn
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA; Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Baruch D Kuppermann
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA
| | - M Cristina Kenney
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA; Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, USA.
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RAD51B (rs8017304 and rs2588809), TRIB1 (rs6987702, rs4351379, and rs4351376), COL8A1 (rs13095226), and COL10A1 (rs1064583) Gene Variants with Predisposition to Age-Related Macular Degeneration. DISEASE MARKERS 2019; 2019:5631083. [PMID: 31191752 PMCID: PMC6525907 DOI: 10.1155/2019/5631083] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 03/27/2019] [Indexed: 12/16/2022]
Abstract
Background Age-related macular degeneration (AMD) is a progressive neurodegenerative disease of a central part of the neural retina (macula) and a leading cause of blindness in elderly people. While it is known that the AMD is a multifactorial disease, genetic factors involved in lipid metabolism, inflammation, and neovascularization are currently being widely studied in genome-wide association studies (GWAS). The aim of our study was to evaluate the impact of new single nucleotide polymorphisms (SNPs) in RAD51B, TRIB1, COL8A1, and COL10A1 genes on AMD development. Methods Case-control study involved 254 patients diagnosed with early AMD, 244 patients with exudative AMD, and 942 control subjects. The genotyping of RAD51B (rs8017304 and rs2588809), TRIB1 (rs6987702, rs4351379, and rs4351376), COL8A1 (rs13095226), and COL10A1 (rs1064583) was carried out using TaqMan assays by a real-time polymerase chain reaction (RT-PCR) method. Results Statistically significant difference was found in genotype (TT, TC, and CC) distribution of COL8A1 rs13095226 between exudative AMD and control groups (60.2%, 33.6%, and 6.1% vs. 64.9%, 32.3%, and 2.9%, respectively, p = 0.036). Also, comparing with TT+TC, rs13095226 CC genotype was associated with 3.5-fold increased odds of exudative AMD development (OR = 3.540; 95% CI: 1.415-8.856; p = 0.007). Conclusion Our study revealed a strong association between a variant in COL8A1 (rs13095226) and exudative AMD development.
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Brown EE, DeWeerd AJ, Ildefonso CJ, Lewin AS, Ash JD. Mitochondrial oxidative stress in the retinal pigment epithelium (RPE) led to metabolic dysfunction in both the RPE and retinal photoreceptors. Redox Biol 2019; 24:101201. [PMID: 31039480 PMCID: PMC6488819 DOI: 10.1016/j.redox.2019.101201] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/10/2019] [Accepted: 04/11/2019] [Indexed: 12/22/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of vision loss in the western world. Recent evidence suggests that RPE and photoreceptors have an interconnected metabolism and that mitochondrial damage in RPE is a trigger for degeneration in both RPE and photoreceptors in AMD. To test this hypothesis, this study was designed to induce mitochondrial damage in RPE in mice to determine whether this is sufficient to cause RPE and photoreceptor damage characteristic of AMD. In this study, we conditionally deleted the gene encoding the mitochondrial antioxidant enzyme, manganese superoxide dismutase (MnSOD encoded by Sod2) in the retinal pigment epithelium (RPE) of albino BALB/cJ mice. VMD2-Cre;Sod2flox/flox BALB/cJ mice were housed in either 12-h dark, 12-h 200 lux white lighting (normal light), or 12-h dark, 12-h <10 lux red lighting (dim light). Electroretinography (ERG) and spectral-domain optical coherence tomography (SD-OCT) were performed to assess retinal function and morphology. Immunofluorescence was used to examine protein expression; quantitative RT-PCR was used to measure gene expression. Sod2 knockout (KO) mice had reduced RPE function with age and increased oxidative stress compared to wild type (WT) controls as expected by the cell-specific deletion of Sod2. This was associated with alterations in RPE morphology and the structure and function of RPE mitochondria. In addition, data show a compensatory increase in RPE glycolytic metabolism. The metabolic shift in RPE correlated with severe disruption of photoreceptor mitochondria including a reduction in TOMM20 expression, mitochondrial fragmentation, and reduced COXIII/β-actin levels. These findings demonstrate that mitochondrial oxidative stress can lead to RPE dysfunction and metabolic reprogramming of RPE. Secondary to these changes, photoreceptors also undergo metabolic stress with increased mitochondrial damage. These data are consistent with the hypothesis of a linked metabolism between RPE and photoreceptors and suggest a mechanism of retinal degeneration in dry AMD. Deletion of Sod2 in the RPE led to loss of RPE function. Knockout mice had decreased ATP levels and decreased COXIII/β-actin levels in the RPE. Knockout mice had elevated expression of glycolytic enzymes in the RPE. RPE alterations led to secondary effects on photoreceptors.
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Affiliation(s)
- Emily E Brown
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA; Clinical and Translational Science Institute, University of Florida, Gainesville, FL, USA
| | - Alexander J DeWeerd
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Cristhian J Ildefonso
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - John D Ash
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA.
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Wang M, Lau LI, Sreekumar PG, Spee C, Hinton DR, Sadda SR, Kannan R. Characterization and Regulation of Carrier Proteins of Mitochondrial Glutathione Uptake in Human Retinal Pigment Epithelium Cells. Invest Ophthalmol Vis Sci 2019; 60:500-516. [PMID: 30707752 PMCID: PMC6360990 DOI: 10.1167/iovs.18-25686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose To characterize two mitochondrial membrane transporters 2-oxoglutarate (OGC) and dicarboxylate (DIC) in human RPE (hRPE) and to elucidate their role in the regulation of mitochondrial glutathione (mGSH) uptake and cell death in oxidative stress. Methods The localization of OGC and DIC proteins in confluent hRPE, polarized hRPE monolayers and mouse retina was assessed by immunoblotting and confocal microscopy. Time- and dose-dependent expression of the two carriers were determined after treatment of hRPE with H2O2, phenyl succinate (PS), and butyl malonate (BM), respectively, for 24 hours. The effect of inhibition of OGC and DIC on apoptosis (TUNEL), mGSH, and mtDNA was determined. Silencing of OGC by siRNA knockdown on RPE cell death was studied. Kinetics of caspase 3/7 activation with OGC and DIC inhibitors and effect of cotreatment with glutathione monoethyl ester (GSH-MEE) was determined using the IncuCyte live cell imaging. Results OGC and DIC are expressed in hRPE mitochondria and exhibited a time- and dose-dependent decrease with stress. Pharmacologic inhibition caused a decrease in OGC and DIC in mitochondria without changes in mtDNA and resulted in increased apoptosis and mGSH depletion. GSH-MEE prevented apoptosis through restoration of mGSH. OGC siRNA exacerbated apoptotic cell death in stressed RPE which was inhibited by increased mGSH from GSH-MEE cotreatment. Conclusions Characterization and mechanism of action of two carrier proteins of mGSH uptake in RPE are reported. Regulation of OGC and DIC will be of value in devising therapeutic strategies for retinal disorders such as AMD.
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Affiliation(s)
- Mo Wang
- Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, California, United States
| | - Lin-Ing Lau
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, California, United States
- Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Parameswaran G Sreekumar
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, California, United States
| | - Christine Spee
- Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - David R Hinton
- Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Srinivas R Sadda
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, California, United States
| | - Ram Kannan
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, California, United States
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Felszeghy S, Viiri J, Paterno JJ, Hyttinen JMT, Koskela A, Chen M, Leinonen H, Tanila H, Kivinen N, Koistinen A, Toropainen E, Amadio M, Smedowski A, Reinisalo M, Winiarczyk M, Mackiewicz J, Mutikainen M, Ruotsalainen AK, Kettunen M, Jokivarsi K, Sinha D, Kinnunen K, Petrovski G, Blasiak J, Bjørkøy G, Koskelainen A, Skottman H, Urtti A, Salminen A, Kannan R, Ferrington DA, Xu H, Levonen AL, Tavi P, Kauppinen A, Kaarniranta K. Loss of NRF-2 and PGC-1α genes leads to retinal pigment epithelium damage resembling dry age-related macular degeneration. Redox Biol 2018; 20:1-12. [PMID: 30253279 PMCID: PMC6156745 DOI: 10.1016/j.redox.2018.09.011] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/06/2018] [Accepted: 09/13/2018] [Indexed: 12/30/2022] Open
Abstract
Age-related macular degeneration (AMD) is a multi-factorial disease that is the leading cause of irreversible and severe vision loss in the developed countries. It has been suggested that the pathogenesis of dry AMD involves impaired protein degradation in retinal pigment epithelial cells (RPE). RPE cells are constantly exposed to oxidative stress that may lead to the accumulation of damaged cellular proteins, DNA and lipids and evoke tissue deterioration during the aging process. The ubiquitin-proteasome pathway and the lysosomal/autophagosomal pathway are the two major proteolytic systems in eukaryotic cells. NRF-2 (nuclear factor-erythroid 2-related factor-2) and PGC-1α (peroxisome proliferator-activated receptor gamma coactivator-1 alpha) are master transcription factors in the regulation of cellular detoxification. We investigated the role of NRF-2 and PGC-1α in the regulation of RPE cell structure and function by using global double knockout (dKO) mice. The NRF-2/PGC-1α dKO mice exhibited significant age-dependent RPE degeneration, accumulation of the oxidative stress marker, 4-HNE (4-hydroxynonenal), the endoplasmic reticulum stress markers GRP78 (glucose-regulated protein 78) and ATF4 (activating transcription factor 4), and damaged mitochondria. Moreover, levels of protein ubiquitination and autophagy markers p62/SQSTM1 (sequestosome 1), Beclin-1 and LC3B (microtubule associated protein 1 light chain 3 beta) were significantly increased together with the Iba-1 (ionized calcium binding adaptor molecule 1) mononuclear phagocyte marker and an enlargement of RPE size. These histopathological changes of RPE were accompanied by photoreceptor dysmorphology and vision loss as revealed by electroretinography. Consequently, these novel findings suggest that the NRF-2/PGC-1α dKO mouse is a valuable model for investigating the role of proteasomal and autophagy clearance in the RPE and in the development of dry AMD. NRF-2/PGC-1α dKO mouse model shows a dry AMD-like phenotype. Loss of NRF-2/PGC-1α genes increased oxidative and ER stress in RPE cells. High oxidative stress was associated with impaired autophagy and proteasomal clearance. The pathology becomes manifest as an age-related loss of photoreceptor function.
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Affiliation(s)
- Szabolcs Felszeghy
- Institute of Dentistry, University of Eastern Finland, Kuopio, Finland; Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Johanna Viiri
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland
| | - Jussi J Paterno
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
| | - Juha M T Hyttinen
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland
| | - Ali Koskela
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland
| | - Mei Chen
- The Wellcome-Wolfson Institute of Experimental Medicine Queen's University Belfast, Belfast, UK
| | - Henri Leinonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Heikki Tanila
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Niko Kivinen
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
| | - Arto Koistinen
- SIB Labs, University of Eastern Finland, Kuopio, Finland
| | - Elisa Toropainen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Marialaura Amadio
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Adrian Smedowski
- Chair and Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Mika Reinisalo
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland; School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mateusz Winiarczyk
- Department of Epizootiology, University of Life Sciences of Lublin, Poland; Department of Vitreoretinal Surgery, Medical University of Lublin, Poland
| | - Jerzy Mackiewicz
- Department of Vitreoretinal Surgery, Medical University of Lublin, Poland
| | - Maija Mutikainen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Anna-Kaisa Ruotsalainen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mikko Kettunen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Kimmo Jokivarsi
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Debasish Sinha
- The Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kati Kinnunen
- Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
| | - Goran Petrovski
- Centre of Eye Research, Department of Ophthalmology, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Janusz Blasiak
- Department of Molecular Genetics, University of Lodz, Lodz, Poland
| | - Geir Bjørkøy
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine; Norwegian University of Science and Technology and Department of Technology; University College of Sør-Trøndelag, Trondheim, Norway
| | - Ari Koskelainen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Finland
| | - Heli Skottman
- Faculty of Medicine and Life Sciences, BioMediTech Institute, University of Tampere, Tampere, Finland
| | - Arto Urtti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland; Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki, Finland
| | - Antero Salminen
- Department of Neurology, University of Eastern Finland, Kuopio, Finland
| | - Ram Kannan
- Arnold and Mabel Beckman Macular Research Center, Doheny Eye Institute, Los Angeles, CA, USA
| | - Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, USA
| | - Heping Xu
- The Wellcome-Wolfson Institute of Experimental Medicine Queen's University Belfast, Belfast, UK
| | - Anna-Liisa Levonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Pasi Tavi
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland.
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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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Hyttinen JMT, Viiri J, Kaarniranta K, Błasiak J. Mitochondrial quality control in AMD: does mitophagy play a pivotal role? Cell Mol Life Sci 2018; 75:2991-3008. [PMID: 29777261 PMCID: PMC11105454 DOI: 10.1007/s00018-018-2843-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/25/2018] [Accepted: 05/16/2018] [Indexed: 01/05/2023]
Abstract
Age-related macular degeneration (AMD) is the predominant cause of visual loss in old people in the developed world, whose incidence is increasing. This disease is caused by the decrease in macular function, due to the degeneration of retinal pigment epithelium (RPE) cells. The aged retina is characterised by increased levels of reactive oxygen species (ROS), impaired autophagy, and DNA damage that are linked to AMD pathogenesis. Mitophagy, a mitochondria-specific type of autophagy, is an essential part of mitochondrial quality control, the collective mechanism responsible for this organelle's homeostasis. The abundance of ROS, DNA damage, and the excessive energy consumption in the ageing retina all contribute to the degeneration of RPE cells and their mitochondria. We discuss the role of mitophagy in the cell and argue that its impairment may play a role in AMD pathogenesis. Thus, mitophagy as a potential therapeutic target in AMD and other degenerative diseases is as well explored.
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Affiliation(s)
- Juha M T Hyttinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
| | - Johanna Viiri
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, 70029 KYS, Kuopio, Finland
| | - Janusz Błasiak
- Department of Molecular Genetics, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland
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49
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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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50
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Abstract
The regional susceptibility of the retina to diseases has been well known by clinicians for many years. It is surprising that the implications of these observations have not spawned major research efforts to characterise the structural and functional attributes of the outer retina in different regions of a foveate retina. Without such an effort, the understanding of the disease mechanisms in retinal dystrophies will remain limited and may hamper therapeutic efforts. That outer retinal disease is responsible for over 50% of blind registration in the western world underlines the importance of these considerations.
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Affiliation(s)
- A C Bird
- UCL Institute of Ophthalmology, London, UK.
| | - D Bok
- Jules Stein Eye Institute, University of California, Los Angeles, CA, USA
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