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Cvekl A, Vijg J. Aging of the eye: Lessons from cataracts and age-related macular degeneration. Ageing Res Rev 2024; 99:102407. [PMID: 38977082 DOI: 10.1016/j.arr.2024.102407] [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: 03/11/2024] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 07/10/2024]
Abstract
Aging is the greatest risk factor for chronic human diseases, including many eye diseases. Geroscience aims to understand the effects of the aging process on these diseases, including the genetic, molecular, and cellular mechanisms that underlie the increased risk of disease over the lifetime. Understanding of the aging eye increases general knowledge of the cellular physiology impacted by aging processes at various biological extremes. Two major diseases, age-related cataract and age-related macular degeneration (AMD) are caused by dysfunction of the lens and retina, respectively. Lens transparency and light refraction are mediated by lens fiber cells lacking nuclei and other organelles, which provides a unique opportunity to study a single aging hallmark, i.e., loss of proteostasis, within an environment of limited metabolism. In AMD, local dysfunction of the photoreceptors/retinal pigmented epithelium/Bruch's membrane/choriocapillaris complex in the macula leads to the loss of photoreceptors and eventually loss of central vision, and is driven by nearly all the hallmarks of aging and shares features with Alzheimer's disease, Parkinson's disease, cardiovascular disease, and diabetes. The aging eye can function as a model for studying basic mechanisms of aging and, vice versa, well-defined hallmarks of aging can be used as tools to understand age-related eye disease.
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Affiliation(s)
- Ales Cvekl
- Departments of Genetics and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Jan Vijg
- Departments of Genetics and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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2
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Wu Y, Li X, Fu X, Huang X, Zhang S, Zhao N, Ma X, Saiding Q, Yang M, Tao W, Zhou X, Huang J. Innovative Nanotechnology in Drug Delivery Systems for Advanced Treatment of Posterior Segment Ocular Diseases. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403399. [PMID: 39031809 DOI: 10.1002/advs.202403399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/29/2024] [Indexed: 07/22/2024]
Abstract
Funduscopic diseases, including diabetic retinopathy (DR) and age-related macular degeneration (AMD), significantly impact global visual health, leading to impaired vision and irreversible blindness. Delivering drugs to the posterior segment of the eye remains a challenge due to the presence of multiple physiological and anatomical barriers. Conventional drug delivery methods often prove ineffective and may cause side effects. Nanomaterials, characterized by their small size, large surface area, tunable properties, and biocompatibility, enhance the permeability, stability, and targeting of drugs. Ocular nanomaterials encompass a wide range, including lipid nanomaterials, polymer nanomaterials, metal nanomaterials, carbon nanomaterials, quantum dot nanomaterials, and so on. These innovative materials, often combined with hydrogels and exosomes, are engineered to address multiple mechanisms, including macrophage polarization, reactive oxygen species (ROS) scavenging, and anti-vascular endothelial growth factor (VEGF). Compared to conventional modalities, nanomedicines achieve regulated and sustained delivery, reduced administration frequency, prolonged drug action, and minimized side effects. This study delves into the obstacles encountered in drug delivery to the posterior segment and highlights the progress facilitated by nanomedicine. Prospectively, these findings pave the way for next-generation ocular drug delivery systems and deeper clinical research, aiming to refine treatments, alleviate the burden on patients, and ultimately improve visual health globally.
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Affiliation(s)
- Yue Wu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
| | - Xin Li
- Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Xueyu Fu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
| | - Xiaomin Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
| | - Shenrong Zhang
- Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Nan Zhao
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
| | - Xiaowei Ma
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
| | - Qimanguli Saiding
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Mei Yang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
| | - Wei Tao
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Xingtao Zhou
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
| | - Jinhai Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; NHC Key Laboratory of Myopia and Related Eye Diseases; Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200031, China
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3
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Chen M, Wang Y, Dalal R, Du J, Vollrath D. Alternative oxidase blunts pseudohypoxia and photoreceptor degeneration due to RPE mitochondrial dysfunction. Proc Natl Acad Sci U S A 2024; 121:e2402384121. [PMID: 38865272 PMCID: PMC11194566 DOI: 10.1073/pnas.2402384121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/15/2024] [Indexed: 06/14/2024] Open
Abstract
Loss of mitochondrial electron transport complex (ETC) function in the retinal pigment epithelium (RPE) in vivo results in RPE dedifferentiation and progressive photoreceptor degeneration, and has been implicated in the pathogenesis of age-related macular degeneration. Xenogenic expression of alternative oxidases in mammalian cells and tissues mitigates phenotypes arising from some mitochondrial electron transport defects, but can exacerbate others. We expressed an alternative oxidase from Ciona intestinalis (AOX) in ETC-deficient murine RPE in vivo to assess the retinal consequences of stimulating coenzyme Q oxidation and respiration without ATP generation. RPE-restricted expression of AOX in this context is surprisingly beneficial. This focused intervention mitigates RPE mTORC1 activation, dedifferentiation, hypertrophy, stress marker expression, pseudohypoxia, and aerobic glycolysis. These RPE cell autonomous changes are accompanied by increased glucose delivery to photoreceptors with attendant improvements in photoreceptor structure and function. RPE-restricted AOX expression normalizes accumulated levels of succinate and 2-hydroxyglutarate in ETC-deficient RPE, and counteracts deficiencies in numerous neural retinal metabolites. These features can be attributed to the activation of mitochondrial inner membrane flavoproteins such as succinate dehydrogenase and proline dehydrogenase, and alleviation of inhibition of 2-oxyglutarate-dependent dioxygenases such as prolyl hydroxylases and epigenetic modifiers. Our work underscores the importance to outer retinal health of coenzyme Q oxidation in the RPE and identifies a metabolic network critical for photoreceptor survival in the context of RPE mitochondrial dysfunction.
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Affiliation(s)
- Ming Chen
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
| | - Yekai Wang
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
| | - Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
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Brodzka S, Baszyński J, Rektor K, Hołderna-Bona K, Stanek E, Kurhaluk N, Tkaczenko H, Malukiewicz G, Woźniak A, Kamiński P. Immunogenetic and Environmental Factors in Age-Related Macular Disease. Int J Mol Sci 2024; 25:6567. [PMID: 38928273 PMCID: PMC11203563 DOI: 10.3390/ijms25126567] [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: 03/24/2024] [Revised: 06/08/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Age-related macular degeneration (AMD) is a chronic disease, which often develops in older people, but this is not the rule. AMD pathogenesis changes include the anatomical and functional complex. As a result of damage, it occurs, in the retina and macula, among other areas. These changes may lead to partial or total loss of vision. This disease can occur in two clinical forms, i.e., dry (progression is slowly and gradually) and exudative (wet, progression is acute and severe), which usually started as dry form. A coexistence of both forms is possible. AMD etiology is not fully understood. Extensive genetic studies have shown that this disease is multifactorial and that genetic determinants, along with environmental and metabolic-functional factors, are important risk factors. This article reviews the impact of heavy metals, macro- and microelements, and genetic factors on the development of AMD. We present the current state of knowledge about the influence of environmental factors and genetic determinants on the progression of AMD in the confrontation with our own research conducted on the Polish population from Kuyavian-Pomeranian and Lubusz Regions. Our research is concentrated on showing how polluted environments of large agglomerations affects the development of AMD. In addition to confirming heavy metal accumulation, the growth of risk of acute phase factors and polymorphism in the genetic material in AMD development, it will also help in the detection of new markers of this disease. This will lead to a better understanding of the etiology of AMD and will help to establish prevention and early treatment.
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Affiliation(s)
- Sylwia Brodzka
- Division of Ecology and Environmental Protection, Department of Medical Biology and Biochemistry, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, M. Skłodowska-Curie St. 9, PL 85-094 Bydgoszcz, Poland; (S.B.); (J.B.); (K.H.-B.); (E.S.)
- Department of Biotechnology, Institute of Biological Sciences, Faculty of Biological Sciences, University of Zielona Góra, Prof. Z. Szafran St. 1, PL 65-516 Zielona Góra, Poland;
| | - Jędrzej Baszyński
- Division of Ecology and Environmental Protection, Department of Medical Biology and Biochemistry, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, M. Skłodowska-Curie St. 9, PL 85-094 Bydgoszcz, Poland; (S.B.); (J.B.); (K.H.-B.); (E.S.)
| | - Katarzyna Rektor
- Department of Biotechnology, Institute of Biological Sciences, Faculty of Biological Sciences, University of Zielona Góra, Prof. Z. Szafran St. 1, PL 65-516 Zielona Góra, Poland;
| | - Karolina Hołderna-Bona
- Division of Ecology and Environmental Protection, Department of Medical Biology and Biochemistry, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, M. Skłodowska-Curie St. 9, PL 85-094 Bydgoszcz, Poland; (S.B.); (J.B.); (K.H.-B.); (E.S.)
| | - Emilia Stanek
- Division of Ecology and Environmental Protection, Department of Medical Biology and Biochemistry, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, M. Skłodowska-Curie St. 9, PL 85-094 Bydgoszcz, Poland; (S.B.); (J.B.); (K.H.-B.); (E.S.)
| | - Natalia Kurhaluk
- Institute of Biology, Pomeranian University in Słupsk, Arciszewski St. 22 B, PL 76-200 Słupsk, Poland; (N.K.); (H.T.)
| | - Halina Tkaczenko
- Institute of Biology, Pomeranian University in Słupsk, Arciszewski St. 22 B, PL 76-200 Słupsk, Poland; (N.K.); (H.T.)
| | - Grażyna Malukiewicz
- Department of Eye Diseases, University Hospital No. 1, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, M. Skłodowska-Curie St. 9, PL 85-092 Bydgoszcz, Poland;
| | - Alina Woźniak
- Department of Medical Biology and Biochemistry, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, M. Karłowicz St. 24, PL 85-092 Bydgoszcz, Poland;
| | - Piotr Kamiński
- Division of Ecology and Environmental Protection, Department of Medical Biology and Biochemistry, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, M. Skłodowska-Curie St. 9, PL 85-094 Bydgoszcz, Poland; (S.B.); (J.B.); (K.H.-B.); (E.S.)
- Department of Biotechnology, Institute of Biological Sciences, Faculty of Biological Sciences, University of Zielona Góra, Prof. Z. Szafran St. 1, PL 65-516 Zielona Góra, Poland;
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Xu Y, Tummala SR, Chen X, Vardi N. VDAC in Retinal Health and Disease. Biomolecules 2024; 14:654. [PMID: 38927058 PMCID: PMC11201675 DOI: 10.3390/biom14060654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/22/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
The retina, a tissue of the central nervous system, is vital for vision as its photoreceptors capture light and transform it into electrical signals, which are further processed before they are sent to the brain to be interpreted as images. The retina is unique in that it is continuously exposed to light and has the highest metabolic rate and demand for energy amongst all the tissues in the body. Consequently, the retina is very susceptible to oxidative stress. VDAC, a pore in the outer membrane of mitochondria, shuttles metabolites between mitochondria and the cytosol and normally protects cells from oxidative damage, but when a cell's integrity is greatly compromised it initiates cell death. There are three isoforms of VDAC, and existing evidence indicates that all three are expressed in the retina. However, their precise localization and function in each cell type is unknown. It appears that most retinal cells express substantial amounts of VDAC2 and VDAC3, presumably to protect them from oxidative stress. Photoreceptors express VDAC2, HK2, and PKM2-key proteins in the Warburg pathway that also protect these cells. Consistent with its role in initiating cell death, VDAC is overexpressed in the retinal degenerative diseases retinitis pigmentosa, age related macular degeneration (AMD), and glaucoma. Treatment with antioxidants or inhibiting VDAC oligomerization reduced its expression and improved cell survival. Thus, VDAC may be a promising therapeutic candidate for the treatment of these diseases.
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Affiliation(s)
- Ying Xu
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (Y.X.); (X.C.)
| | - Shanti R. Tummala
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Xiongmin Chen
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (Y.X.); (X.C.)
| | - Noga Vardi
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, USA
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Zhang CJ, Mou H, Yuan J, Wang YH, Sun SN, Wang W, Xu ZH, Yu SJ, Jin K, Jin ZB. Effects of fluorescent protein tdTomato on mouse retina. Exp Eye Res 2024; 243:109910. [PMID: 38663720 DOI: 10.1016/j.exer.2024.109910] [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: 06/14/2023] [Revised: 02/26/2024] [Accepted: 04/22/2024] [Indexed: 04/30/2024]
Abstract
Fluorescent proteins (FPs) have been widely used to investigate cellular and molecular interactions and trace biological events in many applications. Some of the FPs have been demonstrated to cause undesirable cellular damage by light-induced ROS production in vivo or in vitro. However, it remains unknown if one of the most popular FPs, tdTomato, has similar effects in neuronal cells. In this study, we discovered that tdTomato expression led to unexpected retinal dysfunction and ultrastructural defects in the transgenic mouse retina. The retinal dysfunction mainly manifested in the reduced photopic electroretinogram (ERG) responses and decreased contrast sensitivity in visual acuity, caused by mitochondrial damages characterized with cellular redistribution, morphological modifications and molecular profiling alterations. Taken together, our findings for the first time demonstrated the retinal dysfunction and ultrastructural defects in the retinas of tdTomato-transgenic mice, calling for a more careful design and interpretation of experiments involved in FPs.
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Affiliation(s)
- Chang-Jun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Hao Mou
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Jing Yuan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Ya-Han Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Shu-Ning Sun
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Wen Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Ze-Hua Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Si-Jian Yu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Kangxin Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China.
| | - Zi-Bing Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China.
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Szilágyi A, Takács B, Szekeres R, Tarjányi V, Nagy D, Priksz D, Bombicz M, Kiss R, Szabó AM, Lehoczki A, Gesztelyi R, Juhász B, Szilvássy Z, Varga B. Effects of voluntary and forced physical exercise on the retinal health of aging Wistar rats. GeroScience 2024:10.1007/s11357-024-01208-x. [PMID: 38795184 DOI: 10.1007/s11357-024-01208-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/13/2024] [Indexed: 05/27/2024] Open
Abstract
Aging is accompanied by an increased prevalence of degenerative conditions, including those affecting ocular health, which significantly impact quality of life and increase the burden on healthcare systems. Among these, retinal aging is of particular concern due to its direct link to vision impairment, a leading cause of disability in the elderly. Vision loss in the aging population is associated with heightened risks of cognitive decline, social isolation, and morbidity. This study addresses the critical gap in our understanding of modifiable lifestyle factors, such as physical exercise, that may mitigate retinal aging and its related pathologies. We investigated the effects of different exercise regimens-voluntary (recreational-type) and forced (high-intensity)-on the retinal health of aging Wistar rats (18-month-old), serving as a model for studying the translational potential of exercise interventions in humans. Male Wistar rats were divided into four groups: a young control (3-month-old) for baseline comparison, an aged sedentary control, an aged group engaging in voluntary exercise via a running wheel in their cage, and an aged group subjected to forced exercise on a treadmill for six sessions of 20 min each per week. After a 6-month experimental period, we assessed retinal function via electroretinography (ERG), measured retinal thickness histologically, and analyzed protein expression changes relevant to oxidative stress, inflammation, and anti-aging mechanisms. Our findings reveal that voluntary exercise positively impacts retinal function and morphology, reducing oxidative stress and inflammation markers while enhancing anti-aging protein expression. In contrast, forced exercise showed diminished benefits. These insights underscore the importance of exercise intensity and preference in preserving retinal health during aging. The study highlights the potential of recreational physical activity as a non-invasive strategy to counteract retinal aging, advocating for further research into exercise regimens as preventative therapies for age-related ocular degenerations.
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Affiliation(s)
- Anna Szilágyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Barbara Takács
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Réka Szekeres
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Vera Tarjányi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Dávid Nagy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Dániel Priksz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Mariann Bombicz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Rita Kiss
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Adrienn Mónika Szabó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Andrea Lehoczki
- Departments of Hematology and Stem Cell Transplantation, South Pest Central Hospital, National Institute of Hematology and Infectious Diseases, Saint Ladislaus Campus, Budapest, Hungary
- Department of Public Health, Semmelweis University, Budapest, Hungary
- Doctoral College, Health Sciences Program, Semmelweis University, Budapest, Hungary
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Béla Juhász
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Zoltán Szilvássy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary
| | - Balázs Varga
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 98., 4032, Debrecen, Hungary.
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8
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Al-Bassam L, Shearman GC, Brocchini S, Alany RG, Williams GR. The Potential of Selenium-Based Therapies for Ocular Oxidative Stress. Pharmaceutics 2024; 16:631. [PMID: 38794293 PMCID: PMC11125443 DOI: 10.3390/pharmaceutics16050631] [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: 03/27/2024] [Revised: 04/26/2024] [Accepted: 05/01/2024] [Indexed: 05/26/2024] Open
Abstract
Oxidative stress plays a critical role in the development of chronic ocular conditions including cataracts, age-related macular degeneration, and diabetic retinopathy. There is a need to explore the potential of topical antioxidants to slow the progression of those conditions by mediating oxidative stress and maintaining ocular health. Selenium has attracted considerable attention because it is a component of selenoproteins and antioxidant enzymes. The application of selenium to a patient can increase selenoprotein expression, counteracting the effect of reactive oxygen species by increasing the presence of antioxidant enzymes, and thus slowing the progression of chronic ocular disorders. Oxidative stress effects at the biomolecular level for prevalent ocular conditions are described in this review along with some of the known defensive mechanisms, with a focus on selenoproteins. The importance of selenium in the eye is described, along with a discussion of selenium studies and uses. Selenium's antioxidant and anti-inflammatory qualities may prevent or delay eye diseases. Recent breakthroughs in drug delivery methods and nanotechnology for selenium-based ocular medication delivery are enumerated. Different types of selenium may be employed in formulations aimed at managing ocular oxidative stress conditions.
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Affiliation(s)
- Lulwah Al-Bassam
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK; (L.A.-B.); (S.B.)
| | - Gemma C. Shearman
- School of Life Sciences, Pharmacy and Chemistry, Kingston University London, Penrhyn Rd, Kingston upon Thames KT1 2EE, UK; (G.C.S.); (R.G.A.)
| | - Steve Brocchini
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK; (L.A.-B.); (S.B.)
| | - Raid G. Alany
- School of Life Sciences, Pharmacy and Chemistry, Kingston University London, Penrhyn Rd, Kingston upon Thames KT1 2EE, UK; (G.C.S.); (R.G.A.)
- School of Pharmacy, The University of Auckland, Auckland 1142, New Zealand
| | - Gareth R. Williams
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK; (L.A.-B.); (S.B.)
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Faura G, Studenovska H, Sekac D, Ellederova Z, Petrovski G, Eide L. The Effects of the Coating and Aging of Biodegradable Polylactic Acid Membranes on In Vitro Primary Human Retinal Pigment Epithelium Cells. Biomedicines 2024; 12:966. [PMID: 38790928 PMCID: PMC11117638 DOI: 10.3390/biomedicines12050966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/17/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024] Open
Abstract
Age-related macular degeneration (AMD) is the most frequent cause of blindness in developed countries. The replacement of dysfunctional human retinal pigment epithelium (hRPE) cells by the transplantation of in vitro-cultivated hRPE cells to the affected area emerges as a feasible strategy for regenerative therapy. Synthetic biomimetic membranes arise as powerful hRPE cell carriers, but as biodegradability is a requirement, it also poses a challenge due to its limited durability. hRPE cells exhibit several characteristics that putatively respond to the type of membrane carrier, and they can be used as biomarkers to evaluate and further optimize such membranes. Here, we analyze the pigmentation, transepithelial resistance, genome integrity, and maturation markers of hRPE cells plated on commercial polycarbonate (PC) versus in-house electrospun polylactide-based (PLA) membranes, both enabling separate apical/basolateral compartments. Our results show that PLA is superior to PC-based membranes for the cultivation of hRPEs, and the BEST1/RPE65 maturation markers emerge as the best biomarkers for addressing the quality of hRPE cultivated in vitro. The stability of the cultures was observed to be affected by PLA aging, which is an effect that could be partially palliated by the coating of the PLA membranes.
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Affiliation(s)
- Georgina Faura
- Department of Medical Biochemistry, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway
- CIDETEC, Basque Research and Technology Alliance (BRTA), 20014 Donostia-San Sebastián, Spain
| | - Hana Studenovska
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 00 Prague, Czech Republic;
| | - David Sekac
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, 277 21 Libechov, Czech Republic; (D.S.); (Z.E.)
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Zdenka Ellederova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, 277 21 Libechov, Czech Republic; (D.S.); (Z.E.)
| | - Goran Petrovski
- Center for Eye Research and Innovative Diagnostics, Department of Ophthalmology, Oslo University Hospital and Institute for Clinical Medicine, University of Oslo, 0424 Oslo, Norway;
- Norwegian Center for Stem Cell Research, Oslo University Hospital, 0424 Oslo, Norway
- Department of Ophthalmology, University Hospital Centre, University of Split School of Medicine, 21000 Split, Croatia
- UKLO Network, University St. Kliment Ohridski, 7000 Bitola, North Macedonia
| | - Lars Eide
- Department of Medical Biochemistry, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway
- Department of Medical Biochemistry, Oslo University Hospital, 0424 Oslo, Norway
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10
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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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11
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Korhonen E. Inflammasome activation in response to aberrations of cellular homeostasis in epithelial cells from human cornea and retina. Acta Ophthalmol 2024; 102 Suppl 281:3-68. [PMID: 38386419 DOI: 10.1111/aos.16646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Accepted: 01/16/2024] [Indexed: 02/24/2024]
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12
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Fasih-Ahmad S, Wang Z, Mishra Z, Vatanatham C, Clark ME, Swain TA, Curcio CA, Owsley C, Sadda SR, Hu ZJ. Potential Structural Biomarkers in 3D Images Validated by the First Functional Biomarker for Early Age-Related Macular Degeneration - ALSTAR2 Baseline. Invest Ophthalmol Vis Sci 2024; 65:1. [PMID: 38300559 PMCID: PMC10846345 DOI: 10.1167/iovs.65.2.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024] Open
Abstract
Purpose Lack of valid end points impedes developing therapeutic strategies for early age-related macular degeneration (AMD). Delayed rod-mediated dark adaptation (RMDA) is the first functional biomarker for incident early AMD. The relationship between RMDA and the status of outer retinal bands on optical coherence tomography (OCT) have not been well defined. This study aims to characterize these relationships in early and intermediate AMD. Methods Baseline data from 476 participants was assessed including eyes with early AMD (n = 138), intermediate AMD (n = 101), and normal aging (n = 237). Participants underwent volume OCT imaging of the macula and rod intercept time (RIT) was measured. The ellipsoid zone (EZ) and interdigitation zone (IZ) on all OCT B-scans of the volumes were segmented. The area of detectable EZ and IZ, and mean thickness of IZ within the Early Treatment Diabetic Retinopathy Study (ETDRS) grid were computed and associations with RIT were assessed by Spearman's correlation coefficient and age adjusted. Results Delayed RMDA (longer RIT) was most strongly associated with less preserved IZ area (r = -0.591; P < 0.001), followed by decreased IZ thickness (r = -0.434; P < 0.001), and EZ area (r = -0.334; P < 0.001). This correlation between RIT and IZ integrity was not apparent when considering normal eyes alone within 1.5 mm of the fovea. Conclusions RMDA is correlated with the status of outer retinal bands in early and intermediate AMD eyes, particularly, the status of the IZ. This correlation is consistent with a previous analysis of only foveal B-scans and is biologically plausible given that retinoid availability, involving transfer at the interface attributed to the IZ, is rate-limiting for RMDA.
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Affiliation(s)
| | - Ziyuan Wang
- Doheny Eye Institute, Pasadena, California, United States
| | - Zubin Mishra
- Doheny Eye Institute, Pasadena, California, United States
| | | | - Mark E Clark
- Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Thomas A Swain
- Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Christine A Curcio
- Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Cynthia Owsley
- Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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13
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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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14
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Chu L, Bi C, Wang C, Zhou H. The Relationship between Complements and Age-Related Macular Degeneration and Its Pathogenesis. J Ophthalmol 2024; 2024:6416773. [PMID: 38205100 PMCID: PMC10776198 DOI: 10.1155/2024/6416773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/08/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024] Open
Abstract
Age-related macular degeneration is a retinal disease that causes permanent loss of central vision in people over the age of 65. Its pathogenesis may be related to mitochondrial dysfunction, inflammation, apoptosis, autophagy, complement, intestinal flora, and lipid disorders. In addition, the patient's genes, age, gender, cardiovascular disease, unhealthy diet, and living habits may also be risk factors for this disease. Complement proteins are widely distributed in serum and tissue fluid. In the early 21st century, a connection was found between the complement cascade and age-related macular degeneration. However, little is known about the effect of complement factors on the pathogenesis of age-related macular degeneration. This article reviews the factors associated with age-related macular degeneration, the relationship between each factor and complement, the related functions, and variants and provides new ideas for the treatment of this disease.
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Affiliation(s)
- Liyuan Chu
- Department of Ophthalmology, China–Japan Union Hospital of Jilin University, Changchun, China
| | - Chaoran Bi
- College of Traditional Chinese Medicine, Hainan Medical University, Haikou, Hainan, China
| | - Caiming Wang
- Department of Ophthalmology, China–Japan Union Hospital of Jilin University, Changchun, China
| | - Hongyan Zhou
- Department of Ophthalmology, China–Japan Union Hospital of Jilin University, Changchun, China
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15
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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: 2] [Impact Index Per Article: 2.0] [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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16
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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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17
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Hernandez BJ, Skiba NP, Plössl K, Strain M, Liu Y, Grigsby D, Kelly U, Cady MA, Manocha V, Maminishkis A, Watkins T, Miller SS, Ashley‐Koch A, Stamer WD, Weber BHF, Bowes Rickman C, Klingeborn M. Polarized Desmosome and Hemidesmosome Shedding via Small Extracellular Vesicles is an Early Indicator of Outer Blood-Retina Barrier Dysfunction. JOURNAL OF EXTRACELLULAR BIOLOGY 2023; 2:e116. [PMID: 38108061 PMCID: PMC10720597 DOI: 10.1002/jex2.116] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/30/2023] [Accepted: 09/11/2023] [Indexed: 12/19/2023]
Abstract
The retinal pigmented epithelium (RPE) constitutes the outer blood-retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age-related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles (EVs) from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of small EVs (sEVs) including exosomes, that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral sEVs from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal-side sub-RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of sEV release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in sEV content, including basal-side specific desmosome and hemidesmosome shedding via sEVs. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age-related retinal diseases (e.g., AMD).
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Affiliation(s)
- Belinda J. Hernandez
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Nikolai P. Skiba
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Karolina Plössl
- Institute of Human GeneticsUniversity of RegensburgRegensburgGermany
| | - Madison Strain
- Duke Molecular Physiology Institute, Department of MedicineDuke UniversityDurhamNorth CarolinaUSA
| | - Yutao Liu
- Department of Cellular Biology and AnatomyAugusta UniversityAugustaGeorgiaUSA
| | - Daniel Grigsby
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Una Kelly
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Martha A. Cady
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Vikram Manocha
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Arvydas Maminishkis
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and DiseaseNational Eye Institute, National Institutes of HealthBethesdaMarylandUSA
| | - TeddiJo Watkins
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- Office of Animal Welfare Assurance, Duke Animal Care and Use ProgramDuke UniversityDurhamNorth CarolinaUSA
| | - Sheldon S. Miller
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and DiseaseNational Eye Institute, National Institutes of HealthBethesdaMarylandUSA
| | - Allison Ashley‐Koch
- Duke Molecular Physiology Institute, Department of MedicineDuke UniversityDurhamNorth CarolinaUSA
| | - W. Daniel Stamer
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- Department of Biomedical EngineeringDuke UniversityDurhamNorth CarolinaUSA
| | - Bernhard H. F. Weber
- Institute of Human GeneticsUniversity of RegensburgRegensburgGermany
- Institute of Clinical Human GeneticsUniversity Hospital RegensburgRegensburgGermany
| | - Catherine Bowes Rickman
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- Department of Cell BiologyDuke UniversityDurhamNorth CarolinaUSA
| | - Mikael Klingeborn
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- McLaughlin Research InstituteGreat FallsMontanaUSA
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18
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Zhang SM, Fan B, Li YL, Zuo ZY, Li GY. Oxidative Stress-Involved Mitophagy of Retinal Pigment Epithelium and Retinal Degenerative Diseases. Cell Mol Neurobiol 2023; 43:3265-3276. [PMID: 37391574 PMCID: PMC10477140 DOI: 10.1007/s10571-023-01383-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/22/2023] [Indexed: 07/02/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly specialized and polarized epithelial cell layer that plays an important role in sustaining the structural and functional integrity of photoreceptors. However, the death of RPE is a common pathological feature in various retinal diseases, especially in age-related macular degeneration (AMD) and diabetic retinopathy (DR). Mitophagy, as a programmed self-degradation of dysfunctional mitochondria, is crucial for maintaining cellular homeostasis and cell survival under stress. RPE contains a high density of mitochondria necessary for it to meet energy demands, so severe stimuli can cause mitochondrial dysfunction and the excess generation of intracellular reactive oxygen species (ROS), which can further trigger oxidative stress-involved mitophagy. In this review, we summarize the classical pathways of oxidative stress-involved mitophagy in RPE and investigate its role in the progression of retinal diseases, aiming to provide a new therapeutic strategy for treating retinal degenerative diseases. The role of mitophagy in AMD and DR. In AMD, excessive ROS production promotes mitophagy in the RPE by activating the Nrf2/p62 pathway, while in DR, ROS may suppress mitophagy by the FOXO3-PINK1/parkin signaling pathway or the TXNIP-mitochondria-lysosome-mediated mitophagy.
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Affiliation(s)
- Si-Ming Zhang
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Bin Fan
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Yu- Lin Li
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Zhao-Yang Zuo
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Guang-Yu Li
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China.
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19
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Fasih-Ahmad S, Wang Z, Mishra Z, Vatanatham C, Clark ME, Swain TA, Curcio CA, Owsley C, Sadda SR, Hu ZJ. Potential Structural Biomarkers in 3D Images Validated by the First Functional Biomarker for Early Age-Related Macular Degeneration - ALSTAR2 Baseline. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.09.10.23295309. [PMID: 37745353 PMCID: PMC10516097 DOI: 10.1101/2023.09.10.23295309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Purpose While intermediate and late age-Related Macular Degeneration (AMD) have been widely investigated, rare studies were focused on the pathophysiologic mechanism of early AMD. Delayed rod-mediated dark adaptation (RMDA) is the first functional biomarker for incident early AMD. The status of outer retinal bands on optical coherence tomography (OCT) may be potential imaging biomarkers and the purpose is to investigate the hypothesis that the integrity of interdigitation zone (IZ) may provide insight into the health of photoreceptors and retinal pigment epithelium (RPE) in early AMD. Methods We establish the structure-function relationship between ellipsoid zone (EZ) integrity and RMDA, and IZ integrity and RMDA in a large-scale OCT dataset from eyes with normal aging (n=237), early AMD (n=138), and intermediate AMD (n=101) by utilizing a novel deep-learning-derived algorithm with manual correction when needed to segment the EZ and IZ on OCT B-scans (57,596 B-scans), and utilizing the AdaptDx device to measure RMDA. Results Our data demonstrates that slower RMDA is associated with less preserved EZ (r = -0.334; p<0.001) and IZ area (r = -0.591; p<0.001), and decreased IZ thickness (r = -0.434; p<0.001). These associations are not apparent when considering normal eyes alone. Conclusions The association with IZ area and RMDA in large-scale data is biologically plausible because retinoid availability and transfer at the interface attributed to IZ is rate-limiting for RMDA. This study supports the hypothesis that the IZ integrity provides insight into the health of photoreceptors and RPE in early AMD and is a potential new imaging biomarker.
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20
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Jiménez-Loygorri JI, Benítez-Fernández R, Viedma-Poyatos Á, Zapata-Muñoz J, Villarejo-Zori B, Gómez-Sintes R, Boya P. Mitophagy in the retina: Viewing mitochondrial homeostasis through a new lens. Prog Retin Eye Res 2023; 96:101205. [PMID: 37454969 DOI: 10.1016/j.preteyeres.2023.101205] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 07/11/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Mitochondrial function is key to support metabolism and homeostasis in the retina, an organ that has one of the highest metabolic rates body-wide and is constantly exposed to photooxidative damage and external stressors. Mitophagy is the selective autophagic degradation of mitochondria within lysosomes, and can be triggered by distinct stimuli such as mitochondrial damage or hypoxia. Here, we review the importance of mitophagy in retinal physiology and pathology. In the developing retina, mitophagy is essential for metabolic reprogramming and differentiation of retina ganglion cells (RGCs). In basal conditions, mitophagy acts as a quality control mechanism, maintaining a healthy mitochondrial pool to meet cellular demands. We summarize the different autophagy- and mitophagy-deficient mouse models described in the literature, and discuss the potential role of mitophagy dysregulation in retinal diseases such as glaucoma, diabetic retinopathy, retinitis pigmentosa, and age-related macular degeneration. Finally, we provide an overview of methods used to monitor mitophagy in vitro, ex vivo, and in vivo. This review highlights the important role of mitophagy in sustaining visual function, and its potential as a putative therapeutic target for retinal and other diseases.
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Affiliation(s)
- Juan Ignacio Jiménez-Loygorri
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Rocío Benítez-Fernández
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland
| | - Álvaro Viedma-Poyatos
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Juan Zapata-Muñoz
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Beatriz Villarejo-Zori
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Raquel Gómez-Sintes
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Patricia Boya
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland.
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21
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Kushwah N, Bora K, Maurya M, Pavlovich MC, Chen J. Oxidative Stress and Antioxidants in Age-Related Macular Degeneration. Antioxidants (Basel) 2023; 12:1379. [PMID: 37507918 PMCID: PMC10376043 DOI: 10.3390/antiox12071379] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
Oxidative stress plays a crucial role in aging-related eye diseases, including age-related macular degeneration (AMD), cataracts, and glaucoma. With age, antioxidant reparative capacity decreases, and excess levels of reactive oxygen species produce oxidative damage in many ocular cell types underling age-related pathologies. In AMD, loss of central vision in the elderly is caused primarily by retinal pigment epithelium (RPE) dysfunction and degeneration and/or choroidal neovascularization that trigger malfunction and loss of photo-sensing photoreceptor cells. Along with various genetic and environmental factors that contribute to AMD, aging and age-related oxidative damage have critical involvement in AMD pathogenesis. To this end, dietary intake of antioxidants is a proven way to scavenge free radicals and to prevent or slow AMD progression. This review focuses on AMD and highlights the pathogenic role of oxidative stress in AMD from both clinical and experimental studies. The beneficial roles of antioxidants and dietary micronutrients in AMD are also summarized.
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Affiliation(s)
| | | | | | | | - Jing Chen
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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22
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Hernandez BJ, Skiba NP, Plößl K, Strain M, Grigsby D, Kelly U, Cady MA, Manocha V, Maminishkis A, Watkins T, Miller SS, Ashley-Koch A, Stamer WD, Weber BHF, Rickman CB, Klingeborn M. Polarized Desmosome and Hemidesmosome Shedding via Exosomes is an Early Indicator of Outer Blood-Retina Barrier Dysfunction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544677. [PMID: 37398366 PMCID: PMC10312606 DOI: 10.1101/2023.06.12.544677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The retinal pigmented epithelium (RPE) constitutes the outer blood-retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age-related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of exosomes that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral exosomes from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal-side sub-RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of exosome release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in exosome content, including basal-side specific desmosome and hemidesmosome shedding via exosomes. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age-related retinal diseases, (e.g., AMD) and broadly from blood-CNS barriers in other neurodegenerative diseases.
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23
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Si Z, Zheng Y, Zhao J. The Role of Retinal Pigment Epithelial Cells in Age-Related Macular Degeneration: Phagocytosis and Autophagy. Biomolecules 2023; 13:901. [PMID: 37371481 DOI: 10.3390/biom13060901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/11/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
Age-related macular degeneration (AMD) causes vision loss in the elderly population. Dry AMD leads to the formation of Drusen, while wet AMD is characterized by cell proliferation and choroidal angiogenesis. The retinal pigment epithelium (RPE) plays a key role in AMD pathogenesis. In particular, helioreceptor renewal depends on outer segment phagocytosis of RPE cells, while RPE autophagy can protect cells from oxidative stress damage. However, when the oxidative stress burden is too high and homeostasis is disturbed, the phagocytosis and autophagy functions of RPE become damaged, leading to AMD development and progression. Hence, characterizing the roles of RPE cell phagocytosis and autophagy in the pathogenesis of AMD can inform the development of potential therapeutic targets to prevent irreversible RPE and photoreceptor cell death, thus protecting against AMD.
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Affiliation(s)
- Zhibo Si
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun 130000, China
| | - Yajuan Zheng
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun 130000, China
| | - Jing Zhao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun 130000, China
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24
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Lenin RR, Koh YH, Zhang Z, Yeo YZ, Parikh BH, Seah I, Wong W, Su X. Dysfunctional Autophagy, Proteostasis, and Mitochondria as a Prelude to Age-Related Macular Degeneration. Int J Mol Sci 2023; 24:ijms24108763. [PMID: 37240109 DOI: 10.3390/ijms24108763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
Retinal pigment epithelial (RPE) cell dysfunction is a key driving force of AMD. RPE cells form a metabolic interface between photoreceptors and choriocapillaris, performing essential functions for retinal homeostasis. Through their multiple functions, RPE cells are constantly exposed to oxidative stress, which leads to the accumulation of damaged proteins, lipids, nucleic acids, and cellular organelles, including mitochondria. As miniature chemical engines of the cell, self-replicating mitochondria are heavily implicated in the aging process through a variety of mechanisms. In the eye, mitochondrial dysfunction is strongly associated with several diseases, including age-related macular degeneration (AMD), which is a leading cause of irreversible vision loss in millions of people globally. Aged mitochondria exhibit decreased rates of oxidative phosphorylation, increased reactive oxygen species (ROS) generation, and increased numbers of mitochondrial DNA mutations. Mitochondrial bioenergetics and autophagy decline during aging because of insufficient free radical scavenger systems, the impairment of DNA repair mechanisms, and reductions in mitochondrial turnover. Recent research has uncovered a much more complex role of mitochondrial function and cytosolic protein translation and proteostasis in AMD pathogenesis. The coupling of autophagy and mitochondrial apoptosis modulates the proteostasis and aging processes. This review aims to summarise and provide a perspective on (i) the current evidence of autophagy, proteostasis, and mitochondrial dysfunction in dry AMD; (ii) current in vitro and in vivo disease models relevant to assessing mitochondrial dysfunction in AMD, and their utility in drug screening; and (iii) ongoing clinical trials targeting mitochondrial dysfunction for AMD therapeutics.
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Affiliation(s)
- Raji Rajesh Lenin
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Department of Medical Research, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - Yi Hui Koh
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Zheting Zhang
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University (NTU), 11 Mandalay Road, Experimental Medicine Building, Singapore 308232, Singapore
| | - Yan Zhuang Yeo
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Bhav Harshad Parikh
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Ivan Seah
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Wendy Wong
- Department of Ophthalmology, National University Hospital (NUH), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
| | - Xinyi Su
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Department of Ophthalmology, National University Hospital (NUH), 1E Kent Ridge Road, NUHS Tower Block Level 7, Singapore 119228, Singapore
- Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6 Discovery Tower, Singapore 169856, Singapore
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25
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Chang YJ, Jenny L, Li YS, Cui X, Kong Y, Li Y, Sparrow J, Tsang S. CRISPR editing demonstrates rs10490924 raised oxidative stress in iPSC-derived retinal cells from patients with ARMS2/HTRA1-related AMD. Proc Natl Acad Sci U S A 2023; 120:e2215005120. [PMID: 37126685 PMCID: PMC10175836 DOI: 10.1073/pnas.2215005120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/07/2023] [Indexed: 05/03/2023] Open
Abstract
Genome-wide association studies (GWAS) have identified genetic risk loci for age-related macular degeneration (AMD) on the chromosome 10q26 (Chr10) locus and are tightly linked: the A69S (G>T) rs10490924 single-nucleotide variant (SNV) and the AATAA-rich insertion-deletion (indel, del443/ins54), which are found in the age-related maculopathy susceptibility 2 (ARMS2) gene, and the G512A (G>A) rs11200638 SNV, which is found in the high-temperature requirement A serine peptidase 1 (HTRA1) promoter. The fourth variant is Y402H complement factor H (CFH), which directs CFH signaling. CRISPR manipulation of retinal pigment epithelium (RPE) cells may allow one to isolate the effects of the individual SNV and thus identify SNV-specific effects on cell phenotype. Clustered regularly interspaced short palindromic repeats (CRISPR) editing demonstrates that rs10490924 raised oxidative stress in induced pluripotent stem cell (iPSC)-derived retinal cells from patients with AMD. Sodium phenylbutyrate preferentially reverses the cell death caused by ARMS2 rs10490924 but not HTRA1 rs11200638. This study serves as a proof of concept for the use of patient-specific iPSCs for functional annotation of tightly linked GWAS to study the etiology of a late-onset disease phenotype. More importantly, we demonstrate that antioxidant administration may be useful for reducing reactive oxidative stress in AMD, a prevalent late-onset neurodegenerative disorder.
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Affiliation(s)
- Ya-Ju Chang
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
| | - Laura A. Jenny
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
| | - Yong-Shi Li
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
| | - Xuan Cui
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
| | - Yang Kong
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
| | - Yao Li
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
| | - Janet R. Sparrow
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
- Department of Ophthalmology, Columbia University, New York, NY10032
- Department of Biomedical Engineering, Columbia University, New York, NY10032
- Department of Pathology and Cell Biology, Columbia University, New York, NY10032
| | - Stephen H. Tsang
- Jonas Children’s Vision Care, Department of Ophthalmology, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY10032
- Department of Ophthalmology, Columbia University, New York, NY10032
- Department of Biomedical Engineering, Columbia University, New York, NY10032
- Department of Pathology and Cell Biology, Columbia University, New York, NY10032
- Institute of Human Nutrition, and Columbia Stem Cell Initiative, Columbia University, New York, NY10032
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26
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Fang WY, Rama Raj P, Wu Z, Abbott C, Luu CD, Naughton M, Guymer RH. Role of sleep-disordered breathing in age-related macular degeneration. BMJ Open Ophthalmol 2023; 8:bmjophth-2022-001203. [PMID: 37278414 DOI: 10.1136/bmjophth-2022-001203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 04/26/2023] [Indexed: 06/07/2023] Open
Abstract
AIMS To examine the association between obstructive sleep apnoea (OSA) and age-related macular degeneration (AMD), and the subphenotype of AMD with reticular pseudodrusen (RPD). METHODS Case-control study with 351 participants (211 AMD and 140 controls) using the Epworth Sleepiness Scale (ESS) and the STOP-BANG Questionnaire (SBQ) validated sleep questionnaires. Participant risk of having moderate-to-severe OSA was determined using a binary risk scale based on the ESS and SBQ combined and an ordinal risk scale based on the SBQ. A prior diagnosis of OSA and whether receiving assisted breathing treatment was also ascertained. Retinal imaging allowed AMD and RPD determination. RESULTS Higher risk of moderate-to-severe OSA according to the binary and ordinal scales was not associated with the presence of AMD (p≥0.519) nor AMD with RPD (p≥0.551). Per point increase in ESS or SBQ questionnaire score was also not associated with AMD nor AMD with RPD (p≥0.252). However, being on assisted breathing treatment for diagnosed OSA was significantly associated with a higher likelihood of having AMD with RPD, but not all AMD, (OR 3.70; p=0.042 and OR 2.70; p=0.149, respectively), when compared with those without diagnosed OSA on treatment. CONCLUSIONS Formally diagnosed OSA undergoing treatment, increased the likelihood of having AMD with RPD, but not overall AMD compared with those who were not undergoing treatment. Risk-based OSA questionnaires showed no difference in risk for all AMD or AMD with RPD. Future research, using formal sleep studies could further explore the potential role of nocturnal hypoxia in AMD.
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Affiliation(s)
- Wendy Ying Fang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Victoria, Australia
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Palaniraj Rama Raj
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Discipline of Clinical Ophthalmology and Eye Health/Save Sight Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Zhichao Wu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Victoria, Australia
| | - Carla Abbott
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Victoria, Australia
| | - Chi D Luu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Victoria, Australia
| | - Matthew Naughton
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
- Department of Respiratory and Sleep Medicine, Alfred Hospital, Melbourne, Victoria, Australia
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Victoria, Australia
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27
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Kaynezhad P, Tachtsidis I, Sivaprasad S, Jeffery G. Watching the human retina breath in real time and the slowing of mitochondrial respiration with age. Sci Rep 2023; 13:6445. [PMID: 37081065 PMCID: PMC10119193 DOI: 10.1038/s41598-023-32897-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/04/2023] [Indexed: 04/22/2023] Open
Abstract
The retina has the greatest metabolic demand in the body particularly in dark adaptation when its sensitivity is enhanced. This requires elevated level of perfusion to sustain mitochondrial activity. However, mitochondrial performance declines with age leading to reduced adaptive ability. We assessed human retina metabolism in vivo using broad band near-infrared spectroscopy (bNIRS), which records colour changes in mitochondria and blood as retinal metabolism shifts in response to changes in environmental luminance. We demonstrate a significant sustained rise in mitochondrial oxidative metabolism in the first 3 min of darkness in subjects under 50 years old. This was not seen in those over 50 years. Choroidal oxygenation declines in < 50 s as mitochondrial metabolism increases, but gradually rises in the > 50 s. Significant group differences in blood oxygenation are apparent in the first 6 min, consistent with mitochondrial demand leading hemodynamic changes. A greater coupling between mitochondrial oxidative metabolism with hemodynamics is revealed in subjects older than 50, possibly due to reduced capacity in the older retina. Rapid in vivo assessment of retinal metabolism with bNIRS provides a route to understanding fundamental physiology and early identification of retinal disease before pathology is established.
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Affiliation(s)
- Pardis Kaynezhad
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London, WC1E6BT, UK
| | - Sobha Sivaprasad
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK.
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28
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Datta S, Cano M, Satyanarayana G, Liu T, Wang L, Wang J, Cheng J, Itoh K, Sharma A, Bhutto I, Kannan R, Qian J, Sinha D, Handa JT. Mitophagy initiates retrograde mitochondrial-nuclear signaling to guide retinal pigment cell heterogeneity. Autophagy 2023; 19:966-983. [PMID: 35921555 PMCID: PMC9980637 DOI: 10.1080/15548627.2022.2109286] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/02/2022] Open
Abstract
Age-related macular degeneration (AMD), the leading cause of blindness among the elderly, is without treatment for early disease. Degenerative retinal pigment epithelial (RPE) cell heterogeneity is a well-recognized but understudied pathogenic factor. Due to the daily phagocytosis of photoreceptor outer segments, unique photo-oxidative stress, and high metabolism for maintaining vision, the RPE has robust macroautophagy/autophagy, and mitochondrial and antioxidant networks. However, the autophagy subtype, mitophagy, in the RPE and AMD is understudied. Here, we found decreased PINK1 (PTEN induced kinase 1) in perifoveal RPE of early AMD eyes. PINK1-deficient RPE have impaired mitophagy and mitochondrial function that triggers death-resistant epithelial-mesenchymal transition (EMT). This reprogramming is mediated by novel retrograde mitochondrial-nuclear signaling (RMNS) through superoxide, NFE2L2 (NFE2 like bZIP transcription factor 2), TXNRD1 (thioredoxin reductase 1), and phosphoinositide 3-kinase (PI3K)-AKT (AKT serine/threonine kinase) that induced canonical transcription factors ZEB1 (zinc finger E-box binding homeobox 1) and SNAI1 (Snail family transcriptional repressor 1) and an EMT transcriptome. NFE2L2 deficiency disrupted RMNS that paradoxically normalized morphology but decreased function and viability. Thus, RPE heterogeneity is defined by the interaction of two cytoprotective pathways that is triggered by mitophagy function. By neutralizing the consequences of impaired mitophagy, an antioxidant dendrimer tropic for the RPE and mitochondria, EMT (a recognized AMD alteration) was abrogated to offer potential therapy for early AMD, a stage without treatment.Abbreviations: ACTB: actin beta; AKT: AKT serine/threonine kinase; AMD: age-related macular degeneration; CCCP: cyanide m-chlorophenyl hydrazone; CDH1: cadherin 1; DAVID: Database for Annotation, Visualization and Integrated Discovery; DHE: dihydroethidium; D-NAC: N-acetyl-l-cysteine conjugated to a poly(amido amine) dendrimer; ECAR: extracellular acidification rate; EMT: epithelial-mesenchymal transition; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GSEA: Gene Set Enrichment Analysis; HSPD1: heat shock protein family D (Hsp60) member 1; IVT: intravitreal; KD: knockdown; LMNA, lamin A/C; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MMP: mitochondrial membrane potential; NAC: N-acetyl-l-cysteine; NQO1: NAD(P)H quinone dehydrogenase 1; NFE2L2: NFE2 like bZIP transcription factor 2; O2-: superoxide anion; OCR: oxygen consumption rate; PI3K: phosphoinositide 3-kinase; PINK1: PTEN induced kinase 1; RMNS: retrograde mitochondrial-nuclear signaling; ROS: reactive oxygen species; RPE: retinal pigment epithelium; SNAI1: snail family transcriptional repressor 1; TJP1: tight junction protein 1; TPP-D-NAC: triphenyl phosphinium and N-acetyl-l-cysteine conjugated to a poly(amido amine) dendrimer; TIMM23: translocase of inner mitochondrial membrane 23; TOMM20: translocase of outer mitochondrial membrane 20; Trig: trigonelline; TXNRD1: thioredoxin reductase 1; VIM: vimentin; WT: wild-type; ZEB1: zinc finger E-box binding homeobox 1.
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Affiliation(s)
- Sayantan Datta
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GAUSA
| | - Marisol Cano
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Ganesh Satyanarayana
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GAUSA
| | - Tongyun Liu
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Lei Wang
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jie Wang
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jie Cheng
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Kie Itoh
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Anjali Sharma
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Imran Bhutto
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | - Jiang Qian
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Debasish Sinha
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - James T. Handa
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
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29
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Analysis of Wild Type and Variant B Cystatin C Interactome in Retinal Pigment Epithelium Cells Reveals Variant B Interacting Mitochondrial Proteins. Cells 2023; 12:cells12050713. [PMID: 36899848 PMCID: PMC10001352 DOI: 10.3390/cells12050713] [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: 12/01/2022] [Revised: 02/09/2023] [Accepted: 02/21/2023] [Indexed: 03/05/2023] Open
Abstract
Cystatin C, a secreted cysteine protease inhibitor, is abundantly expressed in retinal pigment epithelium (RPE) cells. A mutation in the protein's leader sequence, corresponding to formation of an alternate variant B protein, has been linked with an increased risk for both age-related macular degeneration (AMD) and Alzheimer's disease (AD). Variant B cystatin C displays intracellular mistrafficking with partial mitochondrial association. We hypothesized that variant B cystatin C interacts with mitochondrial proteins and impacts mitochondrial function. We sought to determine how the interactome of the disease-related variant B cystatin C differs from that of the wild-type (WT) form. For this purpose, we expressed cystatin C Halo-tag fusion constructs in RPE cells to pull down proteins interacting with either the WT or variant B form, followed by identification and quantification by mass spectrometry. We identified a total of 28 interacting proteins, of which 8 were exclusively pulled down by variant B cystatin C. These included 18 kDa translocator protein (TSPO) and cytochrome B5 type B, both of which are localized to the mitochondrial outer membrane. Variant B cystatin C expression also affected RPE mitochondrial function with increased membrane potential and susceptibility to damage-induced ROS production. The findings help us to understand how variant B cystatin C differs functionally from the WT form and provide leads to RPE processes adversely affected by the variant B genotype.
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30
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Nguyen T, Urrutia-Cabrera D, Wang L, Lees JG, Wang JH, Hung SS, Hewitt AW, Edwards TL, McLenachan S, Chen FK, Lim SY, Luu CD, Guymer R, Wong RC. Knockout of AMD-associated gene POLDIP2 reduces mitochondrial superoxide in human retinal pigment epithelial cells. Aging (Albany NY) 2023; 15:1713-1733. [PMID: 36795578 PMCID: PMC10085620 DOI: 10.18632/aging.204522] [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: 07/16/2022] [Accepted: 02/01/2023] [Indexed: 02/17/2023]
Abstract
Genetic and epidemiologic studies have significantly advanced our understanding of the genetic factors contributing to age-related macular degeneration (AMD). In particular, recent expression quantitative trait loci (eQTL) studies have highlighted POLDIP2 as a significant gene that confers risk of developing AMD. However, the role of POLDIP2 in retinal cells such as retinal pigment epithelium (RPE) and how it contributes to AMD pathology are unknown. Here we report the generation of a stable human RPE cell line ARPE-19 with POLDIP2 knockout using CRISPR/Cas, providing an in vitro model to investigate the functions of POLDIP2. We conducted functional studies on the POLDIP2 knockout cell line and showed that it retained normal levels of cell proliferation, cell viability, phagocytosis and autophagy. Also, we performed RNA sequencing to profile the transcriptome of POLDIP2 knockout cells. Our results highlighted significant changes in genes involved in immune response, complement activation, oxidative damage and vascular development. We showed that loss of POLDIP2 caused a reduction in mitochondrial superoxide levels, which is consistent with the upregulation of the mitochondrial superoxide dismutase SOD2. In conclusion, this study demonstrates a novel link between POLDIP2 and SOD2 in ARPE-19, which supports a potential role of POLDIP2 in regulating oxidative stress in AMD pathology.
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Affiliation(s)
- Tu Nguyen
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Daniel Urrutia-Cabrera
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Luozixian Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Jarmon G. Lees
- O’Brien Institute Department, St Vincent’s Institute of Medical Research, Melbourne, Victoria, Australia
- Departments of Surgery and Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Sandy S.C. Hung
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Alex W. Hewitt
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
- Menzies Institute for Medical Research, School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Thomas L. Edwards
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Sam McLenachan
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Fred K. Chen
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Shiang Y. Lim
- O’Brien Institute Department, St Vincent’s Institute of Medical Research, Melbourne, Victoria, Australia
- Departments of Surgery and Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Chi D. Luu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Robyn Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Raymond C.B. Wong
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
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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: 3] [Impact Index Per Article: 3.0] [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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Huynh KT, Walters S, Foley EK, Hunter JJ. Separate lifetime signatures of macaque S cones, M/L cones, and rods observed with adaptive optics fluorescence lifetime ophthalmoscopy. Sci Rep 2023; 13:2456. [PMID: 36774443 PMCID: PMC9922306 DOI: 10.1038/s41598-023-28877-6] [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: 03/09/2022] [Accepted: 01/25/2023] [Indexed: 02/13/2023] Open
Abstract
In the retina, several molecules involved in metabolism, the visual cycle, and other roles exhibit intrinsic fluorescence. The overall properties of retinal fluorescence depend on changes to the composition of these molecules and their environmental interactions due to transient functional shifts, especially in disease. This behooves the understanding of the origins and deviations of these properties within the multilayered retina at high lateral and axial resolution. Of particular interest is the fluorescence lifetime, a potential biomarker of function and disease independent of fluorescence intensity that can be measured in the retina with adaptive optics fluorescence lifetime ophthalmoscopy (AOFLIO). This work demonstrates the utility of the phasor method of analysis, an alternate approach to traditional multiexponential fitting, to evaluate photoreceptor two-photon excited AOFLIO data and separate them based on functional differences. Phasor analysis on fluorescence lifetime decay data allowed the repeatable segregation of S from M/L cones, likely from differences in functional or metabolic demands. Furthermore, it is possible to track the lifetime changes in S cones after photodamage. Phasor analysis increases the sensitivity of AOFLIO to functional differences between cells and has the potential to improve our understanding of pathways involved in normal and diseased conditions at the cellular scale throughout the retina.
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Affiliation(s)
- Khang T Huynh
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA.
- Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA.
| | - Sarah Walters
- Currently with IDEX Health & Science, West Henrietta, NY, 14586, USA
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA
| | - Emma K Foley
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
| | - Jennifer J Hunter
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
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Shen S, Kapphahn RJ, Zhang M, Qian S, Montezuma SR, Shang P, Ferrington DA, Qu J. Quantitative Proteomics of Human Retinal Pigment Epithelium Reveals Key Regulators for the Pathogenesis of Age-Related Macular Degeneration. Int J Mol Sci 2023; 24:3252. [PMID: 36834668 PMCID: PMC9959910 DOI: 10.3390/ijms24043252] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in elderly people, with limited treatment options available for most patients. AMD involves the death of retinal pigment epithelium (RPE) and photoreceptor cells, with mitochondria dysfunction being a critical early event. In the current study, we utilized our unique resource of human donor RPE graded for AMD presence and severity to investigate proteome-wide dysregulation involved in early AMD. Organelle-enriched fractions of RPE were isolated from donors with early AMD (n = 45) and healthy age-matched controls (n = 32) and were analyzed by UHR-IonStar, an integrated proteomics platform enabling reliable and in-depth proteomic quantification in large cohorts. A total of 5941 proteins were quantified with excellent analytical reproducibility, and with further informatics analysis, many biological functions and pathways were found to be significantly dysregulated in donor RPE samples with early AMD. Several of these directly pinpointed changes in mitochondrial functions, e.g., translation, ATP metabolic process, lipid homeostasis, and oxidative stress. These novel findings highlighted the value of our proteomics investigation by allowing a better understanding of the molecular mechanisms underlying early AMD onset and facilitating both treatment development and biomarker discovery.
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Affiliation(s)
- Shichen Shen
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY 14214, USA
- New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY 14203, USA
| | - Rebecca J. Kapphahn
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ming Zhang
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY 14214, USA
- New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY 14203, USA
| | - Shuo Qian
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14203, USA
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Peng Shang
- Doheny Eye Institute, Pasadena, CA 91103, USA
| | - Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
- Doheny Eye Institute, Pasadena, CA 91103, USA
| | - Jun Qu
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY 14214, USA
- New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY 14203, USA
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The Anti-Aging Hormone Klotho Promotes Retinal Pigment Epithelium Cell Viability and Metabolism by Activating the AMPK/PGC-1α Pathway. Antioxidants (Basel) 2023; 12:antiox12020385. [PMID: 36829944 PMCID: PMC9952846 DOI: 10.3390/antiox12020385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/30/2023] [Accepted: 01/30/2023] [Indexed: 02/08/2023] Open
Abstract
Initially discovered by Makuto Kuro-o in 1997, Klotho is a putative aging-suppressor gene when overexpressed and accelerates aging when deleted in mice. Previously, we showed that α-Klotho regulates retinal pigment epithelium (RPE) functions and protects against oxidative stress. However, the mechanisms by which Klotho influences RPE and retinal homeostasis remain elusive. Here, by performing a series of in vitro and in vivo experiments, we demonstrate that Klotho regulates cell viability under oxidative stress, mitochondrial gene expression and activity by inducing the phosphorylation of AMPK and p38MAPK, which in turn phosphorylate and activate CREB and ATF2, respectively, triggering PGC-1α transcription. The inhibition of Klotho in human RPE cells using CRISPR-Cas9 gene editing confirmed that a lack of Klotho negatively affects RPE functions, including mitochondrial activity and cell viability. Proteomic analyses showed that myelin sheath and mitochondrial-related proteins are downregulated in the RPE/retina of Kl-/- compared to WT mice, further supporting our biochemical observations. We conclude that Klotho acts upstream of the AMPK/PGC-1α pathway and regulates RPE/retinal resistance to oxidative stress, mitochondrial function, and gene and protein expressions. Thus, KL decline during aging could negatively impact retinal health, inducing age-related retinal degeneration.
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Francisco SG, Rowan S. Repurposing Drugs for Treatment of Age-Related Macular Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:73-77. [PMID: 37440017 DOI: 10.1007/978-3-031-27681-1_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The need for new drugs to treat dry forms of age-related macular degeneration remains high. A promising approach is repurposing of FDA-approved medications to treat AMD. Databases containing medical and drug records allow for retroactive identification of drugs whose use correlates with reduced AMD diagnosis. This short review summarizes progress in several classes of drugs considered for repurposing: GPR-143 agonists (L-DOPA), anti-diabetic drugs (metformin, acarbose, empagliflozin, fenofibrate), mitochondrial activators (PU-91), and serotonin pathway drugs (fluoxetine, flibanserin, xaliproden, buspirone). The promises and caveats of repurposing are discussed herein.
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Affiliation(s)
- Sarah G Francisco
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA
| | - Sheldon Rowan
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
- Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA.
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
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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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Dissecting Regulators of Aging and Age-Related Macular Degeneration in the Retinal Pigment Epithelium. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:6009787. [PMID: 36439688 PMCID: PMC9683958 DOI: 10.1155/2022/6009787] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022]
Abstract
Age-related macular degeneration (AMD), the leading cause of blindness in elderly populations, involves the loss of central vision due to progressive dysfunction of the retinal pigment epithelium (RPE) and subsequent loss of light-sensing photoreceptors. While age is a key risk factor, not every aged individual develops AMD. Thus, the critical question is what specific cellular changes tip the balance from healthy aging to disease. To distinguish between changes associated with aging and AMD, we compared the RPE proteome in human eye bank tissue from nondiseased donors during aging (n = 50, 29-91 years) and in donors with AMD (n = 36) compared to age-matched donors without disease (n = 28). Proteins from RPE cells were separated on two-dimensional gels, analyzed for content, and identified using mass spectrometry. A total of 58 proteins displayed significantly altered content with either aging or AMD. Proteins involved in metabolism, protein turnover, stress response, and cell death were altered with both aging and AMD. However, the direction of change was predominantly opposite. With aging, we detected an overall decrease in metabolism and reductions in stress-associated proteins, proteases, and chaperones. With AMD, we observed upregulation of metabolic proteins involved in glycolysis, TCA, and fatty acid metabolism, with a concurrent decline in oxidative phosphorylation, suggesting a reprogramming of energy utilization. Additionally, we detected upregulation of proteins involved in the stress response and protein turnover. Predicted upstream regulators also showed divergent results, with inhibition of inflammation and immune response with aging and activation of these processes with AMD. Our results support the idea that AMD is not simply advanced aging but rather the culmination of perturbed protein homeostasis, defective bioenergetics, and increased oxidative stress within the aging RPE, exacerbated by environmental factors and the genetic background of an individual.
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38
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Wu SF, Lin CY, Tsai RK, Wen YT, Lin FH, Chang CY, Shen CI, Lin SZ, Harn HJ, Chiou TW, Liu CS, Chen YT, Su HL. Mitochondrial Transplantation Moderately Ameliorates Retinal Degeneration in Royal College of Surgeons Rats. Biomedicines 2022; 10:2883. [PMID: 36359403 PMCID: PMC9687640 DOI: 10.3390/biomedicines10112883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/09/2022] [Accepted: 11/03/2022] [Indexed: 01/26/2024] Open
Abstract
Retinal pigmented epithelial (RPE) cells possess high mitochondria content for energy production, which is required for phagocytosis and vision cycle metabolism. The mitochondrial integrity in RPE cells helps the homeostasis of photoreceptor turnover and prevents retina aging and degeneration. Mitochondrial transplantation benefits the recovery of several acute inflammatory diseases, leading us to investigate the effects of mitochondrial transplantation on retina degeneration. Allogeneic mitochondria were isolated and delivered into the vitreous chamber in the Royal College of Surgeons (RCS) rats, which exhibit inherited and early-onset retina degeneration. The progress of retina degeneration was examined with optical coherence tomography (OCT) and visual evoked potential (VEP) to determine the retina thickness and integrity of afferent electrical signals from affected eyes, respectively. We found that mitochondria engraftment moderately attenuated the degeneration of retinal layers in RCS rats by histological examination. This result was consistent with the OCT measurement of retina thickness around the optic disc. The VEP analysis revealed that the peak one (N1) latency, representing the arriving time of electrical impulse from the retina to cortex, was substantially maintained as the normal value after the mitochondrial transplantation. This result suggests that the intra-vitreous transplanted mitochondria ameliorate the degeneration of photoreceptors in RCS rats and might be potential for clinical application.
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Affiliation(s)
- Shih-Fang Wu
- The Joint Ph.D. Program in Tissue Engineering and Regenerative Medicine, National Health Research Institutes and National Chung Hsing University, Taichung 402, Taiwan
| | - Chih-Yao Lin
- Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan
| | - Rong-Kung Tsai
- Institute of Eye Research, Buddhist Tzu Chi Hospital, Hualien 970, Taiwan
| | - Yao-Tseng Wen
- Institute of Eye Research, Buddhist Tzu Chi Hospital, Hualien 970, Taiwan
| | - Feng-Huei Lin
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli 350, Taiwan
| | - Chia-Yu Chang
- Bioinnovation Center, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
| | - Ching-I Shen
- Duogenic Stem Cells Corporation, Taichung 402, Taiwan
| | - Shinn-Zong Lin
- Bioinnovation Center, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
- Department of Neurosurgery, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
| | - Horng-Jyh Harn
- Bioinnovation Center, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
- Department of Pathology, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
| | - Tzyy-Wen Chiou
- Department of Life Science and Graduate Institute of Biotechnology, National Dong Hwa University, Hualien 974, Taiwan
| | - Chin-San Liu
- Vascular and Genomic Center, Changhua Christian Hospital, Changhua 500, Taiwan
- Departments of Neurology, Changhua Christian Hospital, Changhua 500, Taiwan
| | - Yan-Ting Chen
- Departments of Ophthalmology, Changhua Christian Hospital, Changhua 500, Taiwan
| | - Hong-Lin Su
- Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan
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Noh SE, Lee SJ, Lee TG, Park KS, Kim JH. Inhibition of Cellular Senescence Hallmarks by Mitochondrial Transplantation in Senescence-induced ARPE-19 cells. Neurobiol Aging 2022; 121:157-165. [DOI: 10.1016/j.neurobiolaging.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 10/03/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022]
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Heloterä H, Kaarniranta K. A Linkage between Angiogenesis and Inflammation in Neovascular Age-Related Macular Degeneration. Cells 2022; 11:cells11213453. [PMID: 36359849 PMCID: PMC9654543 DOI: 10.3390/cells11213453] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/25/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of visual impairment in the aging population with a limited understanding of its pathogenesis and the number of patients are all the time increasing. AMD is classified into two main forms: dry and neovascular AMD (nAMD). Dry AMD is the most prevalent form (80–90%) of AMD cases. Neovascular AMD (10–20% of AMD cases) is treated with monthly or more sparsely given intravitreal anti-vascular endothelial growth factor inhibitors, but unfortunately, not all patients respond to the current treatments. A clinical hallmark of nAMD is choroidal neovascularization. The progression of AMD is initially characterized by atrophic alterations in the retinal pigment epithelium, as well as the formation of lysosomal lipofuscin and extracellular drusen deposits. Cellular damage caused by chronic oxidative stress, protein aggregation and inflammatory processes may lead to advanced geographic atrophy and/or choroidal neovascularization and fibrosis. Currently, it is not fully known why different AMD phenotypes develop. In this review, we connect angiogenesis and inflammatory regulators in the development of nAMD and discuss therapy challenges and hopes.
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Affiliation(s)
- Hanna Heloterä
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, 70211 Kuopio, Finland
- Correspondence:
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, 70211 Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, 70210 Kuopio, Finland
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Zhuang X, Ma J, Xu G, Sun Z. SHP-1 knockdown suppresses mitochondrial biogenesis and aggravates mitochondria-dependent apoptosis induced by all trans retinal through the STING/AMPK pathways. Mol Med 2022; 28:125. [PMID: 36273174 PMCID: PMC9588232 DOI: 10.1186/s10020-022-00554-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 10/06/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Oxidative stress-caused damage to the retinal pigment epithelium (RPE) underlies the onset and progression of age-related macular degeneration (AMD). Impaired mitochondrial biogenesis sensitizes RPE cells to mitochondrial dysfunction, energy insufficiency and death. Src-homology 2 domain-containing phosphatase (SHP)-1 is important in regulating immune responses and cell survival. However, its roles in cell survival are not always consistent. Until now, the effects of SHP-1 on RPE dysfunction, especially mitochondrial homeostasis, remain to be elucidated. We sought to clarify the effects of SHP-1 in RPE cells in response to atRAL-induced oxidative stress and determine the regulatory mechanisms involved. METHODS In the all trans retinal (atRAL)-induced oxidative stress model, we used the vector of lentivirus to knockdown the expression of SHP-1 in ARPE-19 cells. CCK-8 assay, Annexin V/PI staining and JC-1 staining were utilized to determine the cell viability, cell apoptosis and mitochondrial membrane potential. We also used immunoprecipitation to examine the ubiquitination modification of stimulator of interferon genes (STING) and its interaction with SHP-1. The expression levels of mitochondrial marker, proteins related to mitochondrial biogenesis, and signaling molecules involved were examined by western blotting analysis. RESULTS We found that SHP-1 knockdown predisposed RPE cells to apoptosis, aggravated mitochondrial damage, and repressed mitochondrial biogenesis after treatment with atRAL. Immunofluoresent staining and immunoprecipitation analysis confirmed that SHP-1 interacted with the endoplasmic reticulum-resident STING and suppressed K63-linked ubiquitination and activation of STING. Inhibition of STING with the specific antagonist H151 attenuated the effects of SHP-1 knockdown on mitochondrial biogenesis and oxidative damage. The adenosine monophosphate-activated protein kinase (AMPK) pathway acted as the crucial downstream target of STING and was involved in the regulatory processes. CONCLUSIONS These findings suggest that SHP-1 knockdown potentiates STING overactivation and represses mitochondrial biogenesis and cell survival, at least in part by blocking the AMPK pathway in RPE cells. Therefore, restoring mitochondrial health by regulating SHP-1 in RPE cells may be a potential therapeutic strategy for degenerative retinal diseases including AMD.
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Affiliation(s)
- Xiaonan Zhuang
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Jun Ma
- Eye Institute, Eye & ENT Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Gezhi Xu
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Zhongcui Sun
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China.
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.
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Saßmannshausen M, Behning C, Isselmann B, Schmid M, Finger RP, Holz FG, Schmitz-Valckenberg S, Pfau M, Thiele S. Relative ellipsoid zone reflectivity and its association with disease severity in age-related macular degeneration: a MACUSTAR study report. Sci Rep 2022; 12:14933. [PMID: 36056113 PMCID: PMC9440143 DOI: 10.1038/s41598-022-18875-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/22/2022] [Indexed: 12/03/2022] Open
Abstract
Quantification of the relative ellipsoid zone reflectivity (rEZR) might be a structural surrogate parameter for an early disease progression in the context of age-related macular degeneration (AMD). Within the European multicenter, cross-sectional MACUSTAR study, we have devised an automatic approach to determine the mean rEZR [arbitrary units, AU] at two independent visits in SD-OCT volume scans in study participants. Linear mixed-effects models were applied to analyze the association of AMD stage and AMD associated high-risk features including presence of pigmentary abnormalities, reticular pseudodrusen (RPD), volume of the retinal-pigment-epithelial-drusenoid-complex (RPEDC) with the rEZR. Intra-class correlation coefficients (ICC) were determined for rEZR reliability analysis. Within the overall study cohort (301 participants), we could observe decreased rEZR values (coefficient estimate ± standard error) of - 8.05 ± 2.44 AU (p = 0.0011) in the intermediate and of - 22.35 ± 3.28 AU (p < 0.0001) in the late AMD group. RPD presence was significantly associated with the rEZR in iAMD eyes (- 6.49 ± 3.14 AU; p = 0.0403), while there was a good ICC of 0.846 (95% confidence interval: 0.809; 0.876) in the overall study cohort. This study showed an association of rEZR with increasing disease severity and the presence of iAMD high-risk features. Further studies are necessary to evaluate the rEZR's value as a novel biomarker for AMD and disease progression.
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Affiliation(s)
- Marlene Saßmannshausen
- Department of Ophthalmology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
- GRADE Reading Center, University of Bonn, Bonn, Germany
| | - Charlotte Behning
- Institute for Medical Biometry, Informatics and Epidemiology, University of Bonn, Bonn, Germany
| | - Ben Isselmann
- Department of Ophthalmology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Matthias Schmid
- Institute for Medical Biometry, Informatics and Epidemiology, University of Bonn, Bonn, Germany
| | - Robert P Finger
- Department of Ophthalmology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Frank G Holz
- Department of Ophthalmology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
- GRADE Reading Center, University of Bonn, Bonn, Germany
| | - Steffen Schmitz-Valckenberg
- Department of Ophthalmology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
- GRADE Reading Center, University of Bonn, Bonn, Germany
- John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA
| | - Maximilian Pfau
- Department of Ophthalmology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
- GRADE Reading Center, University of Bonn, Bonn, Germany
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, USA
| | - Sarah Thiele
- Department of Ophthalmology, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
- GRADE Reading Center, University of Bonn, Bonn, Germany.
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Abidi M, Karrer E, Csaky K, Handa JT. A Clinical and Preclinical Assessment of Clinical Trials for Dry Age-Related Macular Degeneration. OPHTHALMOLOGY SCIENCE 2022; 2:100213. [PMID: 36570624 PMCID: PMC9767821 DOI: 10.1016/j.xops.2022.100213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 12/27/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness for the elderly in high-income countries. Although multivitamin antioxidant nutrients can slow the progression of intermediate "dry" or nonneovascular AMD, no treatment can halt or reverse any stage of dry disease. Multiple biologic pathways have been implicated in AMD pathobiology, including the complement pathway. These pathways have been targeted by various approaches in clinical trials. To date, no treatment has reached their prespecified primary end point in 2 phase III trials, a requirement by the US Food and Drug Administration for a new drug approval. Here, we describe perspectives on the failures and possible successes of various clinical trials that will guide further investigation. These perspectives will also discuss clinical trial design issues to consider in future investigations, and how recent insights into AMD pathobiology might both provide additional explanation for trials not reaching the prespecified primary end points and offer direction for identifying prioritized treatment targets.
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Affiliation(s)
- Muhammad Abidi
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
| | - Erik Karrer
- Character Biosciences, Inc., San Carlos, California
| | - Karl Csaky
- Retina Institute of the Southwest, Dallas, Texas
| | - James T. Handa
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland,Correspondence: James T. Handa, MD, Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, 400 N. Broadway, Smith 3015, Baltimore, MD 21287.
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Martins TGDS, Sipahi AM, Mendes MA, Fowler SB, Schor P. Metaboloma use in ophthalmology. REVISTA BRASILEIRA DE OFTALMOLOGIA 2022. [DOI: 10.37039/1982.8551.20220056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Senabouth A, Daniszewski M, Lidgerwood GE, Liang HH, Hernández D, Mirzaei M, Keenan SN, Zhang R, Han X, Neavin D, Rooney L, Lopez Sanchez MIG, Gulluyan L, Paulo JA, Clarke L, Kearns LS, Gnanasambandapillai V, Chan CL, Nguyen U, Steinmann AM, McCloy RA, Farbehi N, Gupta VK, Mackey DA, Bylsma G, Verma N, MacGregor S, Watt MJ, Guymer RH, Powell JE, Hewitt AW, Pébay A. Transcriptomic and proteomic retinal pigment epithelium signatures of age-related macular degeneration. Nat Commun 2022; 13:4233. [PMID: 35882847 PMCID: PMC9325891 DOI: 10.1038/s41467-022-31707-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 06/29/2022] [Indexed: 11/08/2022] Open
Abstract
There are currently no treatments for geographic atrophy, the advanced form of age-related macular degeneration. Hence, innovative studies are needed to model this condition and prevent or delay its progression. Induced pluripotent stem cells generated from patients with geographic atrophy and healthy individuals were differentiated to retinal pigment epithelium. Integrating transcriptional profiles of 127,659 retinal pigment epithelium cells generated from 43 individuals with geographic atrophy and 36 controls with genotype data, we identify 445 expression quantitative trait loci in cis that are asssociated with disease status and specific to retinal pigment epithelium subpopulations. Transcriptomics and proteomics approaches identify molecular pathways significantly upregulated in geographic atrophy, including in mitochondrial functions, metabolic pathways and extracellular cellular matrix reorganization. Five significant protein quantitative trait loci that regulate protein expression in the retinal pigment epithelium and in geographic atrophy are identified - two of which share variants with cis- expression quantitative trait loci, including proteins involved in mitochondrial biology and neurodegeneration. Investigation of mitochondrial metabolism confirms mitochondrial dysfunction as a core constitutive difference of the retinal pigment epithelium from patients with geographic atrophy. This study uncovers important differences in retinal pigment epithelium homeostasis associated with geographic atrophy.
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Affiliation(s)
- Anne Senabouth
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Maciej Daniszewski
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | - Grace E Lidgerwood
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | - Helena H Liang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | - Damián Hernández
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | - Mehdi Mirzaei
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Stacey N Keenan
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ran Zhang
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Xikun Han
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - Drew Neavin
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Louise Rooney
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | | | - Lerna Gulluyan
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Linda Clarke
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | - Lisa S Kearns
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
| | | | - Chia-Ling Chan
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Uyen Nguyen
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Angela M Steinmann
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Rachael A McCloy
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Nona Farbehi
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia
| | - Vivek K Gupta
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - David A Mackey
- Lions Eye Institute, Centre for Vision Sciences, University of Western Australia, Perth, WA, 6009, Australia
- School of Medicine, University of Tasmania, Hobart, TAS, 7005, Australia
| | - Guy Bylsma
- Lions Eye Institute, Centre for Vision Sciences, University of Western Australia, Perth, WA, 6009, Australia
| | - Nitin Verma
- School of Medicine, University of Tasmania, Hobart, TAS, 7005, Australia
| | - Stuart MacGregor
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - Matthew J Watt
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
- Department of Surgery, Ophthalmology, Royal Victorian Eye and Ear Hospital, The University of Melbourne, East Melbourne, VIC, 3002, Australia
| | - Joseph E Powell
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia.
- UNSW Cellular Genomics Futures Institute, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Alex W Hewitt
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia.
- School of Medicine, University of Tasmania, Hobart, TAS, 7005, Australia.
- Department of Surgery, Ophthalmology, Royal Victorian Eye and Ear Hospital, The University of Melbourne, East Melbourne, VIC, 3002, Australia.
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, 7000, Australia.
| | - Alice Pébay
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC, 3010, Australia.
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia.
- Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, 3010, Australia.
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Tong Y, Zhang Z, Wang S. Role of Mitochondria in Retinal Pigment Epithelial Aging and Degeneration. FRONTIERS IN AGING 2022; 3:926627. [PMID: 35912040 PMCID: PMC9337215 DOI: 10.3389/fragi.2022.926627] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/21/2022] [Indexed: 12/17/2022]
Abstract
Retinal pigment epithelial (RPE) cells form a monolayer between the neuroretina and choroid. It has multiple important functions, including acting as outer blood-retina barrier, maintaining the function of neuroretina and photoreceptors, participating in the visual cycle and regulating retinal immune response. Due to high oxidative stress environment, RPE cells are vulnerable to dysfunction, cellular senescence, and cell death, which underlies RPE aging and age-related diseases, including age-related macular degeneration (AMD). Mitochondria are the powerhouse of cells and a major source of cellular reactive oxygen species (ROS) that contribute to mitochondrial DNA damage, cell death, senescence, and age-related diseases. Mitochondria also undergo dynamic changes including fission/fusion, biogenesis and mitophagy for quality control in response to stresses. The role of mitochondria, especially mitochondrial dynamics, in RPE aging and age-related diseases, is still unclear. In this review, we summarize the current understanding of mitochondrial function, biogenesis and especially dynamics such as morphological changes and mitophagy in RPE aging and age-related RPE diseases, as well as in the biological processes of RPE cellular senescence and cell death. We also discuss the current preclinical and clinical research efforts to prevent or treat RPE degeneration by restoring mitochondrial function and dynamics.
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Affiliation(s)
- Yao Tong
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
| | - Zunyi Zhang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
| | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
- Department of Ophthalmology, Tulane University, New Orleans, LA, United States
- Tulane Personalized Health Institute, Tulane University, New Orleans, LA, United States
- *Correspondence: Shusheng Wang,
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Ebeling MC, Fisher CR, Kapphahn RJ, Stahl MR, Shen S, Qu J, Montezuma SR, Ferrington DA. Inflammasome Activation in Retinal Pigment Epithelium from Human Donors with Age-Related Macular Degeneration. Cells 2022; 11:2075. [PMID: 35805159 PMCID: PMC9265516 DOI: 10.3390/cells11132075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/23/2022] [Accepted: 06/27/2022] [Indexed: 11/28/2022] Open
Abstract
Age-related macular degeneration (AMD), the leading cause of blindness in the elderly, is characterized by the death of retinal pigment epithelium (RPE) and photoreceptors. One of the risk factors associated with developing AMD is the single nucleotide polymorphism (SNP) found within the gene encoding complement factor H (CFH). Part of the innate immune system, CFH inhibits alternative complement pathway activation. Multi-protein complexes called inflammasomes also play a role in the innate immune response. Previous studies reported that inflammasome activation may contribute to AMD pathology. In this study, we used primary human adult RPE cell cultures from multiple donors, with and without AMD, that were genotyped for the Y402H CFH risk allele. We found complement and inflammasome-related genes and proteins at basal levels in RPE tissue and cell cultures. Additionally, treatment with rotenone, bafilomycin A, and ATP led to inflammasome activation. Overall, the response to priming and activation was similar, irrespective of disease state or CFH genotype. While these data show that the inflammasome is present and active in RPE, our results suggest that inflammasome activation may not contribute to early AMD pathology.
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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.); (C.R.F.); (R.J.K.); (M.R.S.); (S.R.M.)
| | - Cody R. Fisher
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (C.R.F.); (R.J.K.); (M.R.S.); (S.R.M.)
- Graduate Program in Biochemistry, Molecular Biology, and Biophysics, 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.); (C.R.F.); (R.J.K.); (M.R.S.); (S.R.M.)
| | - Madilyn R. Stahl
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (C.R.F.); (R.J.K.); (M.R.S.); (S.R.M.)
| | - Shichen Shen
- Department of Pharmaceutical Sciences, SUNY Buffalo, Buffalo, NY 14203, USA; (S.S.); (J.Q.)
| | - Jun Qu
- Department of Pharmaceutical Sciences, SUNY Buffalo, Buffalo, NY 14203, USA; (S.S.); (J.Q.)
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (C.R.F.); (R.J.K.); (M.R.S.); (S.R.M.)
| | - Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (C.R.F.); (R.J.K.); (M.R.S.); (S.R.M.)
- Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
- Doheny Eye Institute, Pasadena, CA 91103, USA
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Bhattacharya S, Yin J, Huo W, Chaum E. Modeling of mitochondrial bioenergetics and autophagy impairment in MELAS-mutant iPSC-derived retinal pigment epithelial cells. Stem Cell Res Ther 2022; 13:260. [PMID: 35715869 PMCID: PMC9205099 DOI: 10.1186/s13287-022-02937-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 04/30/2022] [Indexed: 11/13/2022] Open
Abstract
Background Mitochondrial dysfunction and mitochondrial DNA (mtDNA) damage in the retinal pigment epithelium (RPE) have been implicated in the pathogenesis of age-related macular degeneration (AMD). However, a deeper understanding is required to determine the contribution of mitochondrial dysfunction and impaired mitochondrial autophagy (mitophagy) to RPE damage and AMD pathobiology. In this study, we model the impact of a prototypical systemic mitochondrial defect, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), in RPE health and homeostasis as an in vitro model for impaired mitochondrial bioenergetics. Methods We used induced pluripotent stem cells (iPSCs) derived from skin biopsies of MELAS patients (m.3243A > G tRNA leu mutation) with different levels of mtDNA heteroplasmy and differentiated them into RPE cells. Mitochondrial depletion of ARPE-19 cells (p0 cells) was also performed using 50 ng/mL ethidium bromide (EtBr) and 50 mg/ml uridine. Cell fusion of the human platelets with the p0 cells performed using polyethylene glycol (PEG)/suspension essential medium (SMEM) mixture to generate platelet/RPE “cybrids.” Confocal microscopy, FLowSight Imaging cytometry, and Seahorse XF Mito Stress test were used to analyze mitochondrial function. Western Blotting was used to analyze expression of autophagy and mitophagy proteins. Results We found that MELAS iPSC-derived RPE cells exhibited key characteristics of native RPE. We observed heteroplasmy-dependent impairment of mitochondrial bioenergetics and reliance on glycolysis for generating energy in the MELAS iPSC-derived RPE. The degree of heteroplasmy was directly associated with increased activation of signal transducer and activator of transcription 3 (STAT3), reduced adenosine monophosphate-activated protein kinase α (AMPKα) activation, and decreased autophagic activity. In addition, impaired autophagy was associated with aberrant lysosomal function, and failure of mitochondrial recycling. The mitochondria-depleted p0 cells replicated the effects on autophagy impairment and aberrant STAT3/AMPKα signaling and showed reduced mitochondrial respiration, demonstrating phenotypic similarities between p0 and MELAS iPSC-derived RPE cells. Conclusions Our studies demonstrate that the MELAS iPSC-derived disease models are powerful tools for dissecting the molecular mechanisms by which mitochondrial DNA alterations influence RPE function in aging and macular degeneration, and for testing novel therapeutics in patients harboring the MELAS genotype. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-022-02937-6.
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Affiliation(s)
- Sujoy Bhattacharya
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, 2311 Pierce Avenue, Nashville, TN, 37232, USA
| | - Jinggang Yin
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, 2311 Pierce Avenue, Nashville, TN, 37232, USA
| | - Weihong Huo
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, 2311 Pierce Avenue, Nashville, TN, 37232, USA
| | - Edward Chaum
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, 2311 Pierce Avenue, Nashville, TN, 37232, USA.
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Hanna J, David LA, Touahri Y, Fleming T, Screaton RA, Schuurmans C. Beyond Genetics: The Role of Metabolism in Photoreceptor Survival, Development and Repair. Front Cell Dev Biol 2022; 10:887764. [PMID: 35663397 PMCID: PMC9157592 DOI: 10.3389/fcell.2022.887764] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/19/2022] [Indexed: 12/11/2022] Open
Abstract
Vision commences in the retina with rod and cone photoreceptors that detect and convert light to electrical signals. The irreversible loss of photoreceptors due to neurodegenerative disease leads to visual impairment and blindness. Interventions now in development include transplanting photoreceptors, committed photoreceptor precursors, or retinal pigment epithelial (RPE) cells, with the latter protecting photoreceptors from dying. However, introducing exogenous human cells in a clinical setting faces both regulatory and supply chain hurdles. Recent work has shown that abnormalities in central cell metabolism pathways are an underlying feature of most neurodegenerative disorders, including those in the retina. Reversal of key metabolic alterations to drive retinal repair thus represents a novel strategy to treat vision loss based on cell regeneration. Here, we review the connection between photoreceptor degeneration and alterations in cell metabolism, along with new insights into how metabolic reprogramming drives both retinal development and repair following damage. The potential impact of metabolic reprogramming on retinal regeneration is also discussed, specifically in the context of how metabolic switches drive both retinal development and the activation of retinal glial cells known as Müller glia. Müller glia display latent regenerative properties in teleost fish, however, their capacity to regenerate new photoreceptors has been lost in mammals. Thus, re-activating the regenerative properties of Müller glia in mammals represents an exciting new area that integrates research into developmental cues, central metabolism, disease mechanisms, and glial cell biology. In addition, we discuss this work in relation to the latest insights gleaned from other tissues (brain, muscle) and regenerative species (zebrafish).
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Affiliation(s)
- Joseph Hanna
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Luke Ajay David
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Yacine Touahri
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Taylor Fleming
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
| | - Robert A. Screaton
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- *Correspondence: Carol Schuurmans,
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Nutraceuticals/Drugs Promoting Mitophagy and Mitochondrial Biogenesis May Combat the Mitochondrial Dysfunction Driving Progression of Dry Age-Related Macular Degeneration. Nutrients 2022; 14:nu14091985. [PMID: 35565950 PMCID: PMC9104458 DOI: 10.3390/nu14091985] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/29/2022] [Accepted: 05/04/2022] [Indexed: 02/07/2023] Open
Abstract
In patients with age-related macular degeneration (AMD), the crucial retinal pigment epithelial (RPE) cells are characterized by mitochondria that are structurally and functionally defective. Moreover, deficient expression of the mRNA-editing enzyme Dicer is noted specifically in these cells. This Dicer deficit up-regulates expression of Alu RNA, which in turn damages mitochondria—inducing the loss of membrane potential, boosting oxidant generation, and causing mitochondrial DNA to translocate to the cytoplasmic region. The cytoplasmic mtDNA, in conjunction with induced oxidative stress, triggers a non-canonical pathway of NLRP3 inflammasome activation, leading to the production of interleukin-18 that acts in an autocrine manner to induce apoptotic death of RPE cells, thereby driving progression of dry AMD. It is proposed that measures which jointly up-regulate mitophagy and mitochondrial biogenesis (MB), by replacing damaged mitochondria with “healthy” new ones, may lessen the adverse impact of Alu RNA on RPE cells, enabling the prevention or control of dry AMD. An analysis of the molecular biology underlying mitophagy/MB and inflammasome activation suggests that nutraceuticals or drugs that can activate Sirt1, AMPK, Nrf2, and PPARα may be useful in this regard. These include ferulic acid, melatonin urolithin A and glucosamine (Sirt1), metformin and berberine (AMPK), lipoic acid and broccoli sprout extract (Nrf2), and fibrate drugs and astaxanthin (PPARα). Hence, nutraceutical regimens providing physiologically meaningful doses of several or all of the: ferulic acid, melatonin, glucosamine, berberine, lipoic acid, and astaxanthin, may have potential for control of dry AMD.
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