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Miyatani T, Tanaka H, Numa K, Uehara A, Otsuki Y, Hamuro J, Kinoshita S, Sotozono C. Clustered ARPE-19 cells distinct in mitochondrial membrane potential may play a pivotal role in cell differentiation. Sci Rep 2024; 14:22391. [PMID: 39333742 PMCID: PMC11436949 DOI: 10.1038/s41598-024-73145-w] [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: 05/22/2024] [Accepted: 09/13/2024] [Indexed: 09/30/2024] Open
Abstract
Age-related macular degeneration (AMD) is associated with the dysfunction and degeneration of retinal pigment epithelium (RPE) cells. Here, we examined how the formation and expansions of cell clusters are regulated by the differentiation of the RPE cells. In this study, ARPE-19 cells were cultivated in standard or differentiation media, i.e., without or with nicotinamide, to evaluate the spreading of cell clusters specified with differentiated cell phenotypes. Mitochondria membrane potential (MMP) and the distribution of the RPE cell clusters was also monitored with or without rotenone, a mitochondrial electron transport chain (ETC) complex I inhibitor. Cultured ARPE-19 cells generated scattered cell clusters composed mostly of smaller size cells expressing the differentiation markers mouse anti-cellular retinaldehyde-binding protein (CRALBP) and Bestrophin only in differentiation medium. After the increase of the number of clusters, the clusters appeared to paracellularly merge, resulting in expansion of the area occupied by the clusters. Of note, the cells within the clusters selectively had high MMP and were in accordance with the expression of RPE differentiation markers. Rotenone repressed the formation of the clusters and decreased intracellular MMP. The above results suggest that clustering of RPE cells with functional mitochondria plays a pivotal role in RPE cell differentiation process and the ETC complex I inhibition greatly influences the composition of RPE cells that are degenerated or differentiation disposed.
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Affiliation(s)
- Takafumi Miyatani
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Hiroshi Tanaka
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan.
| | - Kosaku Numa
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Asako Uehara
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Yohei Otsuki
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Junji Hamuro
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Shigeru Kinoshita
- Department of Frontier Medical Science and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan
| | - Chie Sotozono
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji-agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan
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Seol A, Kim JE, Jin YJ, Song HJ, Roh YJ, Kim TR, Park ES, Park KH, Park SH, Uddin MS, Lee SW, Choi YW, Hwang DY. Novel Therapeutic Effects of Euphorbia heterophylla L. Methanol Extracts in Macular Degeneration Caused by Blue Light in A2E-Laden ARPE-19 Cells and Retina of BALB/c Mice. Pharmaceuticals (Basel) 2024; 17:1193. [PMID: 39338355 PMCID: PMC11435363 DOI: 10.3390/ph17091193] [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: 08/20/2024] [Revised: 09/05/2024] [Accepted: 09/06/2024] [Indexed: 09/30/2024] Open
Abstract
Natural products with high antioxidant activity are considered as innovative prevention strategies to effectively prevent age-related macular degeneration (AMD) in the early stage because the generation of reactive oxygen species (ROS) leading to the development of drusen is reported as an important cause of this disease. To investigate the prevention effects of the methanol extracts of Euphorbia heterophylla L. (MEE) on AMD, its effects on the antioxidant activity, inflammatory response, apoptosis pathway, neovascularization, and retinal tissue degeneration were analyzed in N-retinylidene-N-retinylethanolamine (A2E)-landed spontaneously arising retinal pigment epithelia (ARPE)-19 cells and BALB/c mice after exposure to blue light (BL). The MEE contained 10 active components and showed high free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and nitric oxide (NO) radicals. The pretreatments of high-dose MEE remarkably suppressed the production of intracellular ROS (88.2%) and NO (25.2%) and enhanced (SOD) activity (84%) and the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) in A2E + BL-treated ARPE-19 cells compared to Vehicle-treated group. The activation of the inducible nitric oxide synthase (iNOS)-induced cyclooxygenase-2 (COX-2) mediated pathway, inflammasome activation, and expression of inflammatory cytokines was significantly inhibited in A2E + BL-treated ARPE-19 cells after the MEE pretreatment. The activation of the apoptosis pathway and increased expression of neovascular proteins (36% for matrix metalloproteinase (MMP)-9) were inhibited in the MEE pretreated groups compared to the Vehicle-treated group. Furthermore, the thickness of the whole retina (31%), outer nuclear layer (ONL), inner nuclear layer (INL), and photoreceptor layer (PL) were significantly increased by the MEE pretreatment of BALB/c mice with BL-induced retinal degeneration. Therefore, these results suggest that the MEE, with its high antioxidative activity, protects against BL-induced retinal degeneration through the regulation of the antioxidative system, inflammatory response, apoptosis, and neovascularization in the AMD mouse model.
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Affiliation(s)
- Ayun Seol
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - Ji-Eun Kim
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - You-Jeong Jin
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - Hee-Jin Song
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - Yu-Jeong Roh
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - Tae-Ryeol Kim
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - Eun-Seo Park
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - Ki-Ho Park
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - So-Hae Park
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | | | - Sang-Woo Lee
- International Biological Material Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | - Young-Woo Choi
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
| | - Dae-Youn Hwang
- Department of Biomaterials Science (BK21 FOUR Program), Life and Industry Convergence Research Institute, College of Natural Resources and Life Science, Pusan National University, Miryang 50463, Republic of Korea
- Longevity & Wellbeing Research Center, Laboratory Animals Resources Center, Pusan National University, Miryang 50463, Republic of Korea
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Kim J, Jeon Y, Son J, Pagire HS, Pagire SH, Ahn JH, Uemura A, Lee IK, Park S, Park DH. PDK4-mediated metabolic reprogramming is a potential therapeutic target for neovascular age-related macular degeneration. Cell Death Dis 2024; 15:582. [PMID: 39122684 PMCID: PMC11316003 DOI: 10.1038/s41419-024-06968-0] [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: 04/19/2024] [Revised: 07/30/2024] [Accepted: 08/01/2024] [Indexed: 08/12/2024]
Abstract
Age-related macular degeneration (AMD) causes severe blindness in the elderly due to choroidal neovascularization (CNV), which results from the dysfunction of the retinal pigment epithelium (RPE). While normal RPE depends exclusively on mitochondrial oxidative phosphorylation for energy production, the inflammatory conditions associated with metabolic reprogramming of the RPE play a pivotal role in CNV. Although mitochondrial pyruvate dehydrogenase kinase (PDK) is a central node of energy metabolism, its role in the development of CNV in neovascular AMD has not been investigated. In the present study, we used a laser-induced CNV mouse model to evaluate the effects of Pdk4 gene ablation and treatment with pan-PDK or specific PDK4 inhibitors on fluorescein angiography and CNV lesion area. Among PDK isoforms, only PDK4 was upregulated in the RPE of laser-induced CNV mice, and Pdk4 gene ablation attenuated CNV. Next, we evaluated mitochondrial changes mediated by PDK1-4 inhibition using siRNA or PDK inhibitors in inflammatory cytokine mixture (ICM)-treated primary human RPE (hRPE) cells. PDK4 silencing only in ICM-treated hRPE cells restored mitochondrial respiration and reduced inflammatory cytokine secretion. Likewise, GM10395, a specific PDK4 inhibitor, restored oxidative phosphorylation and decreased ICM-induced upregulation of inflammatory cytokine secretion. In a laser-induced CNV mouse model, GM10395 significantly alleviated CNV. Taken together, we demonstrate that specific PDK4 inhibition could be a therapeutic strategy for neovascular AMD by preventing mitochondrial metabolic reprogramming in the RPE under inflammatory conditions.
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Affiliation(s)
- Juhee Kim
- Department of Ophthalmology, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Republic of Korea
- Kyungpook National University Cell & Matrix Research Institute, Daegu, Republic of Korea
| | - Yujin Jeon
- Department of Ophthalmology, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Republic of Korea
- Kyungpook National University Cell & Matrix Research Institute, Daegu, Republic of Korea
| | - Jinyoung Son
- Department of Biomedical Science, The Graduate School, Kyungpook National University, Daegu, Republic of Korea
- BK21 FOUR KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents, Daegu, Republic of Korea
| | - Haushabhau S Pagire
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
- R&D center, JD Bioscience Inc, Gwangju, Republic of Korea
| | - Suvarna H Pagire
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
- R&D center, JD Bioscience Inc, Gwangju, Republic of Korea
| | - Jin Hee Ahn
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
- R&D center, JD Bioscience Inc, Gwangju, Republic of Korea
| | - Akiyoshi Uemura
- Department of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - In-Kyu Lee
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Republic of Korea
| | - Sungmi Park
- Department of Ophthalmology, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Republic of Korea.
| | - Dong Ho Park
- Department of Ophthalmology, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Republic of Korea.
- Kyungpook National University Cell & Matrix Research Institute, Daegu, Republic of Korea.
- Department of Biomedical Science, The Graduate School, Kyungpook National University, Daegu, Republic of Korea.
- BK21 FOUR KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents, Daegu, Republic of Korea.
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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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Yu Y, Wang G, Liu Y, Meng Z. Potential application of traditional Chinese medicine in age-related macular degeneration-focusing on mitophagy. Front Pharmacol 2024; 15:1410998. [PMID: 38828456 PMCID: PMC11140084 DOI: 10.3389/fphar.2024.1410998] [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: 04/02/2024] [Accepted: 04/30/2024] [Indexed: 06/05/2024] Open
Abstract
Retinal pigment epithelial cell and neuroretinal damage in age-related macular degeneration (AMD) can lead to serious visual impairments and blindness. Studies have shown that mitophagy, a highly specialized cellular degradation system, is implicated in the pathogenesis of AMD. Mitophagy selectively eliminates impaired or non-functioning mitochondria via several pathways, such as the phosphatase and tensin homolog-induced kinase 1/Parkin, BCL2-interacting protein 3 and NIP3-like protein X, FUN14 domain-containing 1, and AMP-activated protein kinase pathways. This has a major impact on the maintenance of mitochondrial homeostasis. Therefore, the regulation of mitophagy could be a promising therapeutic strategy for AMD. Traditional Chinese medicine (TCM) uses natural products that could potentially prevent and treat various diseases, such as AMD. This review aims to summarize recent findings on mitophagy regulation pathways and the latest progress in AMD treatment targeting mitophagy, emphasizing methods involving TCM.
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Affiliation(s)
- Yujia Yu
- First Clinical Medical School, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Gaofeng Wang
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Shandong Province Hospital of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Yong Liu
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Shandong Province Hospital of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Zhaoru Meng
- School of Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
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Iliescu DA, Ghita AC, Ilie LA, Voiculescu SE, Geamanu A, Ghita AM. Non-Neovascular Age-Related Macular Degeneration Assessment: Focus on Optical Coherence Tomography Biomarkers. Diagnostics (Basel) 2024; 14:764. [PMID: 38611677 PMCID: PMC11011935 DOI: 10.3390/diagnostics14070764] [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: 02/28/2024] [Revised: 03/27/2024] [Accepted: 03/31/2024] [Indexed: 04/14/2024] Open
Abstract
The imagistic evaluation of non-neovascular age-related macular degeneration (AMD) is crucial for diagnosis, monitoring progression, and guiding management of the disease. Dry AMD, characterized primarily by the presence of drusen and retinal pigment epithelium atrophy, requires detailed visualization of the retinal structure to assess its severity and progression. Several imaging modalities are pivotal in the evaluation of non-neovascular AMD, including optical coherence tomography, fundus autofluorescence, or color fundus photography. In the context of emerging therapies for geographic atrophy, like pegcetacoplan, it is critical to establish the baseline status of the disease, monitor the development and expansion of geographic atrophy, and to evaluate the retina's response to potential treatments in clinical trials. The present review, while initially providing a comprehensive description of the pathophysiology involved in AMD, aims to offer an overview of the imaging modalities employed in the evaluation of non-neovascular AMD. Special emphasis is placed on the assessment of progression biomarkers as discerned through optical coherence tomography. As the landscape of AMD treatment continues to evolve, advanced imaging techniques will remain at the forefront, enabling clinicians to offer the most effective and tailored treatments to their patients.
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Affiliation(s)
- Daniela Adriana Iliescu
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 8 Eroii Sanitari Bld., 050474 Bucharest, Romania; (S.E.V.); (A.M.G.)
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
| | - Ana Cristina Ghita
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
| | - Larisa Adriana Ilie
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
| | - Suzana Elena Voiculescu
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 8 Eroii Sanitari Bld., 050474 Bucharest, Romania; (S.E.V.); (A.M.G.)
| | - Aida Geamanu
- Ophthalmology Department, Bucharest University Emergency Hospital, 169 Independence Street, 050098 Bucharest, Romania;
| | - Aurelian Mihai Ghita
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 8 Eroii Sanitari Bld., 050474 Bucharest, Romania; (S.E.V.); (A.M.G.)
- Ocularcare Ophthalmology Clinic, 128 Ion Mihalache Bld., 012244 Bucharest, Romania; (A.C.G.); (L.A.I.)
- Ophthalmology Department, Bucharest University Emergency Hospital, 169 Independence Street, 050098 Bucharest, Romania;
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7
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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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Shome I, Thathapudi NC, Aramati BMR, Kowtharapu BS, Jangamreddy JR. Stages, pathogenesis, clinical management and advancements in therapies of age-related macular degeneration. Int Ophthalmol 2023; 43:3891-3909. [PMID: 37347455 DOI: 10.1007/s10792-023-02767-2] [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: 02/16/2022] [Accepted: 06/08/2023] [Indexed: 06/23/2023]
Abstract
Age-related macular degeneration (AMD) is a retinal degenerative disorder prevalent in the elderly population, which leads to the loss of central vision. The disease progression can be managed, if not prevented, either by blocking neovascularization ("wet" form of AMD) or by preserving retinal pigment epithelium and photoreceptor cells ("dry" form of AMD). Although current therapeutic modalities are moderately successful in delaying the progression and management of the disease, advances over the past years in regenerative medicine using iPSC, embryonic stem cells, advanced materials (including nanomaterials) and organ bio-printing show great prospects in restoring vision and efficient management of either forms of AMD. This review focuses on the molecular mechanism of the disease, model systems (both cellular and animal) used in studying AMD, the list of various regenerative therapies and the current treatments available. The article also highlights on the recent clinical trials using regenerative therapies and management of the disease.
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Affiliation(s)
- Ishita Shome
- UR Advanced Therapeutics Private Limited, ASPIRE-BioNest, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Neethi C Thathapudi
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada
- Department of Ophthalmology and Institute of Biomedical Engineering, Université de Montréal, Montréal, QC, Canada
| | - Bindu Madhav Reddy Aramati
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Bhavani S Kowtharapu
- UR Advanced Therapeutics Private Limited, ASPIRE-BioNest, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Jaganmohan R Jangamreddy
- UR Advanced Therapeutics Private Limited, ASPIRE-BioNest, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India.
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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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10
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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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11
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Prokai L, Zaman K, Prokai-Tatrai K. Mass spectrometry-based retina proteomics. MASS SPECTROMETRY REVIEWS 2023; 42:1032-1062. [PMID: 35670041 PMCID: PMC9730434 DOI: 10.1002/mas.21786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
A subfield of neuroproteomics, retina proteomics has experienced a transformative growth since its inception due to methodological advances in enabling chemical, biochemical, and molecular biology techniques. This review focuses on mass spectrometry's contributions to facilitate mammalian and avian retina proteomics to catalog and quantify retinal protein expressions, determine their posttranslational modifications, as well as its applications to study the proteome of the retina in the context of biology, health and diseases, and therapy developments.
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Affiliation(s)
- Laszlo Prokai
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Khadiza Zaman
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Katalin Prokai-Tatrai
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
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12
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Deng L, Gupta V, Abyadeh M, Chitranshi N, Pushpitha K, Wu Y, Gupta V, You Y, Paulo JA, Graham SL, Mirzaei M, Haynes PA. Oxidative Stress Induced Dysfunction of Protein Synthesis in 661W Mice Photoreceptor Cells. Proteomes 2023; 11:12. [PMID: 37092453 PMCID: PMC10123756 DOI: 10.3390/proteomes11020012] [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: 12/05/2022] [Revised: 03/17/2023] [Accepted: 03/22/2023] [Indexed: 04/05/2023] Open
Abstract
Photoreceptor cells are highly susceptible to oxidative-stress-induced damage due to their high metabolic rate. Oxidative stress plays a key role in driving pathological events in several different ocular diseases, which lead to retinal degeneration and ultimately blindness. A growing number of studies have been performed to understand downstream events caused by ROS induced oxidative stress in photoreceptor cells; however, the underlying mechanisms of ROS toxicity are not fully understood. To shed light on ROS induced downstream pathological events, we employed a tandem mass tag (TMT) labelling-based quantitative mass-spectrometric approach to determine proteome changes in 661W photoreceptor cells following oxidative stress induction via the application of different concentrations of H2O2 at different time points. Overall, 5920 proteins were identified and quantified, and 450 differentially expressed proteins (DEPs) were identified, which were altered in a dose and time dependent manner in all treatment groups compared to the control group. These proteins were involved in several biological pathways, including spliceosome and ribosome response, activated glutathione metabolism, decreased ECM-receptor interaction, oxidative phosphorylation, abnormally regulated lysosome, apoptosis, and ribosome biogenesis. Our results highlighted ECM receptor interaction, oxidative phosphorylation and spliceosome pathways as the major targets of oxidative stress that might mediate vascular dysfunction and cellular senescence.
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Affiliation(s)
- Liting Deng
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Vivek Gupta
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | | | - Nitin Chitranshi
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Kanishka Pushpitha
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Yunqi Wu
- Australian Proteome Analysis Facility, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Veer Gupta
- School of Medicine, Deakin University, Geelong, VIC 3220, Australia
| | - Yuyi You
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Joao A. Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Stuart L. Graham
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Mehdi Mirzaei
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Paul A. Haynes
- School of Natural Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
- Biomolecular Discovery Research Centre, Macquarie University, Macquarie Park, NSW 2109, Australia
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13
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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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14
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Mitochondrial Open Reading Frame of the 12S rRNA Type-c: Potential Therapeutic Candidate in Retinal Diseases. Antioxidants (Basel) 2023; 12:antiox12020518. [PMID: 36830076 PMCID: PMC9952431 DOI: 10.3390/antiox12020518] [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: 01/10/2023] [Revised: 02/09/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Mitochondrial open reading frame of the 12S rRNA type-c (MOTS-c) is the most unearthed peptide encoded by mitochondrial DNA (mtDNA). It is an important regulator of the nuclear genome during times of stress because it promotes an adaptive stress response to maintain cellular homeostasis. Identifying MOTS-c specific binding partners may aid in deciphering the complex web of mitochondrial and nuclear-encoded signals. Mitochondrial damage and dysfunction have been linked to aging and the accelerated cell death associated with many types of retinal degenerations. Furthermore, research on MOTS-c ability to revive oxidatively stressed RPE cells has revealed a significant protective role for the molecule. Evidence suggests that senescent cells play a role in the development of age-related retinal disorders. This review examines the links between MOTS-c, mitochondria, and age-related diseases of the retina. Moreover, the untapped potential of MOTS-c as a treatment for glaucoma, diabetic retinopathy, and age-related macular degeneration is reviewed.
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15
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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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16
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Protein-Mediated Carotenoid Delivery Suppresses the Photoinducible Oxidation of Lipofuscin in Retinal Pigment Epithelial Cells. Antioxidants (Basel) 2023; 12:antiox12020413. [PMID: 36829973 PMCID: PMC9952040 DOI: 10.3390/antiox12020413] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
Lipofuscin of retinal pigment epithelium (RPE) cells is a complex heterogeneous system of chromophores which accumulates as granules during the cell's lifespan. Lipofuscin serves as a source of various cytotoxic effects linked with oxidative stress. Several age-related eye diseases such as macular degeneration of the retina, as well as some severe inherited eye pathologies, are accompanied by a significant increase in lipofuscin granule concentration. The accumulation of carotenoids in the RPE could provide an effective antioxidant protection against lipofuscin cytotoxic manifestations. Given the highly lipophilic nature of carotenoids, their targeted delivery to the vulnerable tissues can potentially be assisted by special proteins. In this study, we demonstrate how protein-mediated delivery of zeaxanthin using water-soluble Bombyx mori carotenoid-binding protein (BmCBP-ZEA) suppresses the photoinducible oxidative stress in RPE cells caused by irradiation of lipofuscin with intense white light. We implemented fluorescence lifetime imaging of the RPE cell culture ARPE-19 fed with lipofuscin granules and then irradiated by white light with and without the addition of BmCBP-ZEA. We demonstrate that after irradiation the mean fluorescence lifetime of lipofuscin significantly increases, while the presence of BmCBP-ZEA at 200 nM concentration suppresses the increase in the average lifetime of lipofuscin fluorescence, indicating an approx. 35% inhibition of the oxidative stress. This phenomenon serves as indirect yet important evidence of the efficiency of the protein-mediated carotenoid delivery into pigment epithelium cells.
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17
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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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18
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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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19
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Tear Proteome Revealed Association of S100A Family Proteins and Mesothelin with Thrombosis in Elderly Patients with Retinal Vein Occlusion. Int J Mol Sci 2022; 23:ijms232314653. [PMID: 36498980 PMCID: PMC9736253 DOI: 10.3390/ijms232314653] [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: 09/24/2022] [Revised: 11/03/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Tear samples collected from patients with central retinal vein occlusion (CRVO; n = 28) and healthy volunteers (n = 29) were analyzed using a proteomic label-free absolute quantitative approach. A large proportion (458 proteins with a frequency > 0.6) of tear proteomes was found to be shared between the study groups. Comparative proteomic analysis revealed 29 proteins (p < 0.05) significantly differed between CRVO patients and the control group. Among them, S100A6 (log (2) FC = 1.11, p < 0.001), S100A8 (log (2) FC = 2.45, p < 0.001), S100A9 (log2 (FC) = 2.08, p < 0.001), and mesothelin ((log2 (FC) = 0.82, p < 0.001) were the most abundantly represented upregulated proteins, and β2-microglobulin was the most downregulated protein (log2 (FC) = −2.13, p < 0.001). The selected up- and downregulated proteins were gathered to customize a map of CRVO-related critical protein interactions with quantitative properties. The customized map (FDR < 0.01) revealed inflammation, impairment of retinal hemostasis, and immune response as the main set of processes associated with CRVO ischemic condition. The semantic analysis displayed the prevalence of core biological processes covering dysregulation of mitochondrial organization and utilization of improperly or topologically incorrect folded proteins as a consequence of oxidative stress, and escalating of the ischemic condition caused by the local retinal hemostasis dysregulation. The most significantly different proteins (S100A6, S100A8, S100A9, MSLN, and β2-microglobulin) were applied for the ROC analysis, and their AUC varied from 0.772 to 0.952, suggesting probable association with the CRVO.
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20
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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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21
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Tan LX, Li J, Germer CJ, Lakkaraju A. Analysis of mitochondrial dynamics and function in the retinal pigment epithelium by high-speed high-resolution live imaging. Front Cell Dev Biol 2022; 10:1044672. [PMID: 36393836 PMCID: PMC9651161 DOI: 10.3389/fcell.2022.1044672] [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: 09/14/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial dysfunction is strongly implicated in neurodegenerative diseases including age-related macular degeneration (AMD), which causes irreversible blindness in over 50 million older adults worldwide. A key site of insult in AMD is the retinal pigment epithelium (RPE), a monolayer of postmitotic polarized cells that performs essential functions for photoreceptor health and vision. Recent studies from our group and others have identified several features of mitochondrial dysfunction in AMD including mitochondrial fragmentation and bioenergetic defects. While these studies provide valuable insight at fixed points in time, high-resolution, high-speed live imaging is essential for following mitochondrial injury in real time and identifying disease mechanisms. Here, we demonstrate the advantages of live imaging to investigate RPE mitochondrial dynamics in cell-based and mouse models. We show that mitochondria in the RPE form extensive networks that are destroyed by fixation and discuss important live imaging considerations that can interfere with accurate evaluation of mitochondrial integrity such as RPE differentiation status and acquisition parameters. Our data demonstrate that RPE mitochondria show localized heterogeneities in membrane potential and ATP production that could reflect focal changes in metabolism and oxidative stress. Contacts between the mitochondria and organelles such as the ER and lysosomes mediate calcium flux and mitochondrial fission. Live imaging of mouse RPE flatmounts revealed a striking loss of mitochondrial integrity in albino mouse RPE compared to pigmented mice that could have significant functional consequences for cellular metabolism. Our studies lay a framework to guide experimental design and selection of model systems for evaluating mitochondrial health and function in the RPE.
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Affiliation(s)
- Li Xuan Tan
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
| | - Jianlong Li
- Department of Cell and Tissue Biology, School of Dentistry, University of California, San Francisco, CA, United States
| | - Colin J. Germer
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, United States
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, United States
- Department of Anatomy, School of Medicine, University of California, San Francisco, CA, United States
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22
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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] [Key Words] [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
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23
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Emilsson V, Gudmundsson EF, Jonmundsson T, Jonsson BG, Twarog M, Gudmundsdottir V, Li Z, Finkel N, Poor S, Liu X, Esterberg R, Zhang Y, Jose S, Huang CL, Liao SM, Loureiro J, Zhang Q, Grosskreutz CL, Nguyen AA, Huang Q, Leehy B, Pitts R, Aspelund T, Lamb JR, Jonasson F, Launer LJ, Cotch MF, Jennings LL, Gudnason V, Walshe TE. A proteogenomic signature of age-related macular degeneration in blood. Nat Commun 2022; 13:3401. [PMID: 35697682 PMCID: PMC9192739 DOI: 10.1038/s41467-022-31085-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 06/01/2022] [Indexed: 12/28/2022] Open
Abstract
Age-related macular degeneration (AMD) is one of the most common causes of visual impairment in the elderly, with a complex and still poorly understood etiology. Whole-genome association studies have discovered 34 genomic regions associated with AMD. However, the genes and cognate proteins that mediate the risk, are largely unknown. In the current study, we integrate levels of 4782 human serum proteins with all genetic risk loci for AMD in a large population-based study of the elderly, revealing many proteins and pathways linked to the disease. Serum proteins are also found to reflect AMD severity independent of genetics and predict progression from early to advanced AMD after five years in this population. A two-sample Mendelian randomization study identifies several proteins that are causally related to the disease and are directionally consistent with the observational estimates. In this work, we present a robust and unique framework for elucidating the pathobiology of AMD. Age related macular degeneration is a common cause of visual impairment in the elderly, but the etiology is not fully understood. Here, the authors use genetic data, serum proteomics, and AMD phenotypic data from a large Icelandic cohort to discover proteins altered in, causally related to AMD or signifying progression of advanced AMD.
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Affiliation(s)
- Valur Emilsson
- Icelandic Heart Association, Holtasmari 1, IS-201, Kopavogur, Iceland. .,Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland.
| | | | | | | | - Michael Twarog
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Valborg Gudmundsdottir
- Icelandic Heart Association, Holtasmari 1, IS-201, Kopavogur, Iceland.,Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland
| | - Zhiguang Li
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Bethesda, MD, USA
| | - Nancy Finkel
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Stephen Poor
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Xin Liu
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Robert Esterberg
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Yiyun Zhang
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Sandra Jose
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Chia-Ling Huang
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Sha-Mei Liao
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Joseph Loureiro
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Qin Zhang
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Cynthia L Grosskreutz
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Andrew A Nguyen
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Qian Huang
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Barrett Leehy
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Rebecca Pitts
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Thor Aspelund
- Icelandic Heart Association, Holtasmari 1, IS-201, Kopavogur, Iceland
| | - John R Lamb
- Novartis Institutes for Biomedical Research, 10675 John Jay Hopkins Drive, San Diego, CA, 92121, USA
| | - Fridbert Jonasson
- Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland.,Department of Ophthalmology, University Hospital, Reykjavik, Iceland
| | - Lenore J Launer
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Bethesda, MD, USA
| | - Mary Frances Cotch
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lori L Jennings
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA
| | - Vilmundur Gudnason
- Icelandic Heart Association, Holtasmari 1, IS-201, Kopavogur, Iceland.,Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland
| | - Tony E Walshe
- Novartis Institutes for Biomedical Research, 22 Windsor Street, Cambridge, MA, 02139, USA.
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24
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Garcia-Garcia J, Usategui-Martin R, Sanabria MR, Fernandez-Perez E, Telleria JJ, Coco-Martin RM. Pathophysiology of Age-Related Macular Degeneration: Implications for Treatment. Ophthalmic Res 2022; 65:615-636. [PMID: 35613547 DOI: 10.1159/000524942] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/29/2022] [Indexed: 12/16/2022]
Abstract
Age-related macular degeneration (AMD) is a complex, multifactorial, progressive retinal disease that affects millions of people worldwide and has become the leading cause of visual impairment in developed countries. The disease etiopathogenesis is not understood fully, although many triggers and processes that lead to dysfunction and degeneration of the retinal pigment epithelium (RPE) have already been identified. Thus, the lack of cellular control of oxidative stress, altered proteostasis, dysfunction of lipid homeostasis, and mitochondrial dysfunction form an internal feedback loop that causes the RPE to fail and allows accumulation of abnormal misfolded proteins and abnormal lipids that will form drusen. An inadequate antioxidant response, deficits in autophagy mechanisms, and dysregulation of the extracellular matrix (ECM) help to increase the deposition of abnormal drusen material over time. The drusen then act as inflammatory centers that trigger chronic inflammation of the subretinal space in which microglia and recruited macrophages are also involved, and where the complement system is a key component. Choriocapillaris degeneration and nutritional influences are also classic elements recognized in the AMD pathophysiology. The genetic component of the disease is embodied in the recognition of the described risk or protective polymorphisms of some complement and ECM related genes (mainly CFH and ARMS2/HTRA1). Thus, carriers of the risk haplotype at ARMS2/HTRA1 have a higher risk of developing late AMD at a younger age. Finally, gut microbiota and epigenetics may play a role in modulating the progression to advanced AMD with the presence of local inflammatory conditions. Because of multiple implicated processes, different complex combinations of treatments will probably be the best option to obtain the best visual results; they in turn will differ depending on the type and spectrum of disease affecting individual patients or the disease stage in each patient at a specific moment. This will undoubtedly lead to personalized medicine for control and hopefully find a future cure. This necessitates the continued unraveling of all the processes involved in the pathogenesis of AMD that must be understood to devise the combinations of treatments for different concurrent or subsequent problems.
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Affiliation(s)
- Julián Garcia-Garcia
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
| | - Ricardo Usategui-Martin
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
- RICORS of Inflammation and Immunopathology of Organs and Systems Network, ISCIII, Madrid, Spain
- Dpto. de Biología Celular, Histología y Farmacología, University of Valladolid, Valladolid, Spain
| | - Maria Rosa Sanabria
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
- RICORS of Inflammation and Immunopathology of Organs and Systems Network, ISCIII, Madrid, Spain
- Ophthalmology Department, Palencia University Hospital Complex, Palencia, Spain
| | - Esther Fernandez-Perez
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
| | - Juan Jose Telleria
- Institute of Biology and Molecular Genetics (IBGM) University of Valladolid, Valladolid, Spain
- Dpto. de Biología Celular, Histología y Farmacología, University of Valladolid, Valladolid, Spain
| | - Rosa M Coco-Martin
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
- RICORS of Inflammation and Immunopathology of Organs and Systems Network, ISCIII, Madrid, Spain
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25
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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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26
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Fisher CR, Ebeling MC, Ferrington DA. Quantification of mitophagy using mKeima-mito in cultured human primary retinal pigment epithelial cells. Exp Eye Res 2022; 217:108981. [PMID: 35167864 PMCID: PMC8957530 DOI: 10.1016/j.exer.2022.108981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/25/2022] [Accepted: 02/04/2022] [Indexed: 11/28/2022]
Abstract
The retinal pigment epithelium is a pigmented monolayer of cells that help maintain a healthy retina. Loss of this essential cell layer is implicated in a number of visual disorders, including age-related macular degeneration (AMD). Utilizing primary RPE cultures to investigate disease is an important step in understanding disease mechanisms. However, the use of primary RPE cultures presents a number of challenges, including the limited number of cells available and the presence of auto-fluorescent pigment that interferes with quantifying fluorescent probes. Additionally, primary RPE are difficult to transfect with exogenous nucleic acids traditionally used for fluorescent imaging. To overcome these challenges, we used an adeno-associated viral (AAV) vector to express a pH sensitive fluorescent protein, mKeima, fused to the mitochondrial targeting sequence of cytochrome oxidase subunit 8A (mKeima-mito). mKeima-mito allows for quantification of mitochondrial autophagy (mitophagy) in live-cell time-lapse imaging experiments. We also developed an image analysis pipeline to selectively quantify mKeima-mito while removing the signal of auto-fluorescent pigment from the dataset by utilizing information from the mKeima fluorescent channels. These techniques are demonstrated in primary RPE cultures expressing mKeima-mito treated with 2-[2-[4-(trifluoromethoxy)phenyl]hydrazinylidene]-propanedinitrile (FCCP), an uncoupler that depolarizes the mitochondrial membrane and leads to mitochondrial fragmentation and mitophagy. The techniques outlined provide a roadmap for investigating disease mechanisms or the effect of treatments utilizing fluorescent probes in an important cell culture model.
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Affiliation(s)
- Cody R Fisher
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA; Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Mara C Ebeling
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, 55455, USA; Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA.
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27
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Allingham MJ, Mettu PS, Cousins SW. Phase 1 Clinical Trial of Elamipretide in Intermediate Age-Related Macular Degeneration and High-Risk Drusen. OPHTHALMOLOGY SCIENCE 2022; 2:100095. [PMID: 36246187 PMCID: PMC9560633 DOI: 10.1016/j.xops.2021.100095] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 10/29/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022]
Abstract
Purpose To assess safety, tolerability, and feasibility of subcutaneous administration of the mitochondrial-targeted drug elamipretide in patients with intermediate age-related macular degeneration (AMD) and high-risk drusen (HRD) and to perform exploratory analyses of change in visual function. Design Phase 1, single-center, open-label, 24-week clinical trial with preplanned HRD cohort. Participants Adult patients ≥55 years of age with intermediate AMD and HRD. Methods Participants received subcutaneous elamipretide 40 mg daily, with safety and tolerability assessed throughout the study. Ocular assessments included normal-luminance best-corrected visual acuity (BCVA), low-luminance best-corrected visual acuity (LLVA), normal-luminance binocular reading acuity (NLRA), low-luminance binocular reading acuity (LLRA), spectral-domain OCT, fundus autofluorescence (FAF), mesopic microperimetry, dark adaptation, and low-luminance questionnaire (LLQ). Main Outcome Measures The primary end point was safety and tolerability. Prespecified exploratory end points included changes from baseline in BCVA, LLVA, NLRA, LLRA, retinal pigment epithelium (RPE)-drusen complex (DC) volume by OCT, FAF, mesopic microperimetry, dark adaptation, and LLQ results. Results Subcutaneous administration of elamipretide was highly feasible. All participants with HRD (n = 21) experienced 1 or more adverse events (AEs), but all were mild (57%) or moderate (43%), with the most common events related to injection site reactions. No serious systemic AEs occurred. One participant discontinued because of injection site reaction, 1 participant withdrew because they did not wish to continue study visits, and 1 participant withdrew after experiencing transient visual impairment. Among the 18 participants who completed the study, mean change in BCVA from baseline to 24 weeks was +3.6 letters (P = 0.014) and LLVA was +5.6 letters (P = 0.004). Compared with baseline, mean NLRA improved by –0.11 logarithm of the minimum angle of resolution (logMAR) units (P = 0.001), and LLRA by −0.28 logMAR units (P < 0.0001). Significant improvements were found in 6 of 7 subscales of the LLQ (P<0.0015). No significant changes were observed for RPE-DC volume, FAF, mesopic microperimetry, or dark adaptation. Conclusions Elamipretide appeared to be generally safe and well tolerated in treating intermediate AMD and HRD. Exploratory analyses demonstrate a positive effect on visual function, particularly under low-luminance conditions. Further study of elamipretide for treatment of intermediate AMD with HRD is warranted.
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28
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Ren J, Ren A, Deng X, Huang Z, Jiang Z, Li Z, Gong Y. Long-Chain Polyunsaturated Fatty Acids and Their Metabolites Regulate Inflammation in Age-Related Macular Degeneration. J Inflamm Res 2022; 15:865-880. [PMID: 35173457 PMCID: PMC8842733 DOI: 10.2147/jir.s347231] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/20/2022] [Indexed: 12/24/2022] Open
Abstract
Age-related macular degeneration (AMD) is a blinding eye disease, whose incidence strongly increases with ages. The etiology of AMD is complex, including aging, abnormal lipid metabolism, chronic inflammation and oxidative stress. Long-chain polyunsaturated fatty acids (LCPUFA) are essential for ocular structures and functions. This review summarizes the regulatory effects of LCPUFA on inflammation in AMD. LCPUFA are related to aging, autophagy and chronic inflammation. They are metabolized to pro- and anti-inflammatory metabolites by various enzymes. These metabolites stimulate inflammation in response to oxidative stress, causing innate and acquired immune responses. This review also discusses the possible clinical applications, which provided novel targets for the prevention and treatment of AMD and other age-related diseases.
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Affiliation(s)
- Jiangbo Ren
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
| | - Anli Ren
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
| | - Xizhi Deng
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
| | - Zhengrong Huang
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
| | - Ziyu Jiang
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
| | - Zhi Li
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
| | - Yan Gong
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People’s Republic of China
- Human Genetics Resource Preservation Center of Wuhan University, Wuhan University, Wuhan, Hubei, People’s Republic of China
- Correspondence: Yan Gong; Zhi Li, Tel +86 27 6781 1461; +86 27 6781 2622, Fax +86 27 6781 1471; +86 27 6781 3133, Email ;
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29
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Testing Mitochondrial-Targeted Drugs in iPSC-RPE from Patients with Age-Related Macular Degeneration. Pharmaceuticals (Basel) 2022; 15:ph15010062. [PMID: 35056119 PMCID: PMC8781759 DOI: 10.3390/ph15010062] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/23/2021] [Accepted: 12/27/2021] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. No universally effective treatments exist for atrophic or “dry” AMD, which results from loss of the retinal pigment epithelium (RPE) and photoreceptors and accounts for ≈80% of all AMD patients. Prior studies provide evidence for the involvement of mitochondrial dysfunction in AMD pathology. This study used induced pluripotent stem cell (iPSC) RPE derived from five AMD patients to test the efficacy of three drugs (AICAR (5-Aminoimidazole-4-carboxamide ribonucleotide), Metformin, trehalose) that target key processes in maintaining optimal mitochondrial function. The patient iPSC-RPE lines were used in a proof-of-concept drug screen, utilizing an analysis of RPE mitochondrial function following acute and extended drug exposure. Results show considerable variability in drug response across patient cell lines, supporting the need for a personalized medicine approach for treating AMD. Furthermore, our results demonstrate the feasibility of using iPSC-RPE from AMD patients to develop a personalized drug treatment regime and provide a roadmap for the future clinical management of AMD.
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30
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Hellinen L, Koskela A, Vattulainen E, Liukkonen M, Wegler C, Treyer A, Handin N, Svensson R, Myöhänen T, Poso A, Kaarniranta K, Artursson P, Urtti A. Inhibition of prolyl oligopeptidase: A promising pathway to prevent the progression of age-related macular degeneration. Biomed Pharmacother 2021; 146:112501. [PMID: 34891119 DOI: 10.1016/j.biopha.2021.112501] [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: 10/05/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 01/18/2023] Open
Abstract
Dry age-related macular degeneration (AMD) is a currently untreatable vision threatening disease. Impaired proteasomal clearance and autophagy in the retinal pigment epithelium (RPE) and subsequent photoreceptor damage are connected with dry AMD, but detailed pathophysiology is still unclear. In this paper, we discover inhibition of cytosolic protease, prolyl oligopeptidase (PREP), as a potential pathway to treat dry AMD. We showed that PREP inhibitor exposure induced autophagy in the RPE cells, shown by increased LC3-II levels and decreased p62 levels. PREP inhibitor treatment increased total levels of autophagic vacuoles in the RPE cells. Global proteomics was used to examine the phenotype of a commonly used cell model displaying AMD characteristics, oxidative stress and altered protein metabolism, in vitro. These RPE cells displayed induced protein aggregation and clear alterations in macromolecule metabolism, confirming the relevance of the cell model. Differences in intracellular target engagement of PREP inhibitors were observed with cellular thermal shift assay (CETSA). These differences were explained by intracellular drug exposure (the unbound cellular partition coefficient, Kpuu). Importantly, our data is in line with previous observations regarding the discrepancy between PREP's cleaving activity and outcomes in autophagy. This highlights the need to further explore PREP's role in autophagy so that more effective compounds can be designed to battle diseases in which autophagy induction is needed. The present work is the first report investigating the PREP pathway in the RPE and we predict that the PREP inhibitors can be further optimized for treatment of dry AMD.
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Affiliation(s)
- Laura Hellinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland; Department of Pharmacy, Uppsala University, 751 23 Uppsala, Sweden
| | - Ali Koskela
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FIN-70211 , Finland
| | - Elina Vattulainen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FIN-70211 , Finland
| | - Mikko Liukkonen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FIN-70211 , Finland
| | - Christine Wegler
- Department of Pharmacy, Uppsala University, 751 23 Uppsala, Sweden; Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Uppsala University, 751 23 Uppsala, Sweden
| | - Andrea Treyer
- Department of Pharmacy, Uppsala University, 751 23 Uppsala, Sweden
| | - Niklas Handin
- Department of Pharmacy, Uppsala University, 751 23 Uppsala, Sweden
| | - Richard Svensson
- Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Uppsala University, 751 23 Uppsala, Sweden
| | - Timo Myöhänen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland; Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Finland
| | - Antti Poso
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FIN-70211 , Finland; Department of Ophthalmology, Kuopio University Hospital, P.O. Box 1777, FIN-70211 Kuopio, Finland
| | - Per Artursson
- Department of Pharmacy, Uppsala University, 751 23 Uppsala, Sweden; Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Uppsala University, 751 23 Uppsala, Sweden; Science for Life Laboratory Drug Discovery and Development Platform, Uppsala University, 751 23 Uppsala, Sweden
| | - Arto Urtti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland; Drug Research Programme, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 Helsinki, Finland; Laboratory of Biohybrid Technologies, Institute of Chemistry, St. Petersburg State University, Peterhoff, St. Petersburg 198504, Russia.
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Xu HJ, Li QY, Zou T, Yin ZQ. Development-related mitochondrial properties of retinal pigment epithelium cells derived from hEROs. Int J Ophthalmol 2021; 14:1138-1150. [PMID: 34414076 DOI: 10.18240/ijo.2021.08.02] [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: 02/04/2021] [Accepted: 06/21/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To explore the temporal mitochondrial characteristics of retinal pigment epithelium (RPE) cells obtained from human embryonic stem cells (hESC)-derived retinal organoids (hEROs-RPE), to verify the optimal period for using hEROs-RPE as donor cells from the aspect of mitochondria and to optimize RPE cell-based therapeutic strategies for age-related macular degeneration (AMD). METHODS RPE cells were obtained from hEROs and from spontaneous differentiation (SD-RPE). The mitochondrial characteristics were analyzed every 20d from day 60 to 160. Mitochondrial quantity was measured by MitoTracker Green staining. Transmission electron microscopy (TEM) was adopted to assess the morphological features of the mitochondria, including their distribution, length, and cristae. Mitochondrial membrane potentials (MMPs) were determined by JC-1 staining and evaluated by flow cytometry, reactive oxygen species (ROS) levels were evaluated by flow cytometry, and adenosine triphosphate (ATP) levels were measured by a luminometer. Differences between two groups were analyzed by the independent-samples t-test, and comparisons among multiple groups were made using one-way ANOVA or Kruskal-Wallis H test when equal variance was not assumed. RESULTS hEROs-RPE and SD-RPE cells from day 60 to 160 were successfully differentiated from hESCs and expressed RPE markers (Pax6, MITF, Bestrophin-1, RPE65, Cralbp). RPE features, including a cobblestone-like morphology with tight junctions (ZO-1), pigments and microvilli, were also observed in both hEROs-RPE and SD-RPE cells. The mitochondrial quantities of hEROs-RPE and SD-RPE cells both peaked at day 80. However, the cristae of hEROs-RPE mitochondria were less mature and abundant than those of SD-RPE mitochondria at day 80, with hEROs-RPE mitochondria becoming mature at day 100. Both hEROs-RPE and SD-RPE cells showed low ROS levels from day 100 to 140 and maintained a normal MMP during this period. However, hEROs-RPE mitochondria maintained a longer time to produce high levels of ATP (from day 120 to 140) than SD-RPE cells (only day 120). CONCLUSION hEROs-RPE mitochondria develop more slowly and maintain a longer time to supply high-level energy than SD-RPE mitochondria. From the mitochondrial perspective, hEROs-RPE cells from day 100 to 140 are an optimal cell source for treating AMD.
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Affiliation(s)
- Hao-Jue Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Qi-You Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Ting Zou
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Zheng-Qin Yin
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
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Cano M, Datta S, Wang L, Liu T, Flores‐Bellver M, Sachdeva M, Sinha D, Handa JT. Nrf2 deficiency decreases NADPH from impaired IDH shuttle and pentose phosphate pathway in retinal pigmented epithelial cells to magnify oxidative stress-induced mitochondrial dysfunction. Aging Cell 2021; 20:e13444. [PMID: 34313391 PMCID: PMC8373343 DOI: 10.1111/acel.13444] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 06/26/2021] [Accepted: 07/08/2021] [Indexed: 12/14/2022] Open
Abstract
The nuclear factor‐erythroid 2‐related factor‐2 (Nrf2), a major antioxidant transcription factor, is decreased in several age‐related diseases including age‐related macular degeneration (AMD), the most common cause of blindness among the elderly in western society. Since Nrf2’s mito‐protective response is understudied, we investigated its antioxidant response on mitochondria. Control and Nrf2‐deficient retinal pigmented epithelial (RPE) cells were compared after treating with cigarette smoke extract (CSE). Mitochondrial antioxidant abundance and reactive oxygen species (ROS) were quantified. Mitochondrial function was assessed by TMRM assay, NADPH, electron transport chain activity, and Seahorse. Results were corroborated in Nrf2−/− mice and relevance to AMD was provided by immunohistochemistry of human globes. CSE induced mitochondrial ROS to impair mitochondrial function. H2O2 increase in particular, was magnified by Nrf2 deficiency, and corresponded with exaggerated mitochondrial dysfunction. While Nrf2 did not affect mitochondrial antioxidant abundance, oxidized PRX3 was magnified by Nrf2 deficiency due to decreased NADPH from decreased expression of IDH2 and pentose phosphate pathway (PPP) genes. With severe CSE stress, intrinsic apoptosis was activated to increase cell death. PPP component TALDO1 immunolabeling was decreased in dysmorphic RPE of human AMD globes. Despite limited regulation of mitochondrial antioxidant expression, Nrf2 influences PPP and IDH shuttle activity that indirectly supplies NADPH for the TRX2 system. These results provide insight into how Nrf2 deficiency impacts the mitochondrial antioxidant response, and its role in AMD pathobiology.
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Affiliation(s)
- Marisol Cano
- Wilmer Eye Institute Johns Hopkins School of Medicine Baltimore MD USA
| | - Sayantan Datta
- Wilmer Eye Institute Johns Hopkins School of Medicine Baltimore MD USA
| | - Lei Wang
- Wilmer Eye Institute Johns Hopkins School of Medicine Baltimore MD USA
| | - Tongyun Liu
- Wilmer Eye Institute Johns Hopkins School of Medicine Baltimore MD USA
| | | | - Mira Sachdeva
- Wilmer Eye Institute Johns Hopkins School of Medicine Baltimore MD USA
| | - Debasish Sinha
- Department of Ophthalmology University of Pittsburgh School of Medicine Baltimore MD USA
| | - James T. Handa
- Wilmer Eye Institute Johns Hopkins School of Medicine Baltimore MD USA
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Toma C, De Cillà S, Palumbo A, Garhwal DP, Grossini E. Oxidative and Nitrosative Stress in Age-Related Macular Degeneration: A Review of Their Role in Different Stages of Disease. Antioxidants (Basel) 2021; 10:antiox10050653. [PMID: 33922463 PMCID: PMC8145578 DOI: 10.3390/antiox10050653] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/14/2022] Open
Abstract
Although the exact pathogenetic mechanisms leading to age-related macular degeneration (AMD) have not been clearly identified, oxidative damage in the retina and choroid due to an imbalance between local oxidants/anti-oxidant systems leading to chronic inflammation could represent the trigger event. Different in vitro and in vivo models have demonstrated the involvement of reactive oxygen species generated in a highly oxidative environment in the development of drusen and retinal pigment epithelium (RPE) changes in the initial pathologic processes of AMD; moreover, recent evidence has highlighted the possible association of oxidative stress and neovascular AMD. Nitric oxide (NO), which is known to play a key role in retinal physiological processes and in the regulation of choroidal blood flow, under pathologic conditions could lead to RPE/photoreceptor degeneration due to the generation of peroxynitrite, a potentially cytotoxic tyrosine-nitrating molecule. Furthermore, the altered expression of the different isoforms of NO synthases could be involved in choroidal microvascular changes leading to neovascularization. The purpose of this review was to investigate the different pathways activated by oxidative/nitrosative stress in the pathogenesis of AMD, focusing on the mechanisms leading to neovascularization and on the possible protective role of anti-vascular endothelial growth factor agents in this context.
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Affiliation(s)
- Caterina Toma
- Eye Clinic, University Hospital Maggiore Della Carità, 28100 Novara, Italy; (C.T.); (S.D.C.); (A.P.)
| | - Stefano De Cillà
- Eye Clinic, University Hospital Maggiore Della Carità, 28100 Novara, Italy; (C.T.); (S.D.C.); (A.P.)
- Department of Health Sciences, University East Piedmont “A. Avogadro”, 28100 Novara, Italy
| | - Aurelio Palumbo
- Eye Clinic, University Hospital Maggiore Della Carità, 28100 Novara, Italy; (C.T.); (S.D.C.); (A.P.)
| | - Divya Praveen Garhwal
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University East Piedmont “A. Avogadro”, 28100 Novara, Italy;
| | - Elena Grossini
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University East Piedmont “A. Avogadro”, 28100 Novara, Italy;
- Correspondence: ; Tel.:+39-0321-660526
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Ebeling MC, Geng Z, Kapphahn RJ, Roehrich H, Montezuma SR, Dutton JR, Ferrington DA. Impaired Mitochondrial Function in iPSC-Retinal Pigment Epithelium with the Complement Factor H Polymorphism for Age-Related Macular Degeneration. Cells 2021; 10:cells10040789. [PMID: 33918210 PMCID: PMC8066149 DOI: 10.3390/cells10040789] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 12/27/2022] Open
Abstract
Age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, is characterized by loss of the retinal pigment epithelium (RPE). While the disease mechanism remains unclear, prior studies have linked AMD with RPE mitochondrial defects and genetic polymorphisms in the complement pathway. This study used RPE generated from induced pluripotent stem cells (iPSC-RPE), which were derived from human donors with or without AMD and genotyped for the complement factor H (CFH) AMD high-risk allele (rs1061170, Y402H) to investigate whether donor disease state or genotype had a detrimental effect on mitochondrial function and inflammation. Results show that cells derived from donors with AMD display decreased mitochondrial function under conditions of stress and elevated expression of inflammatory markers compared to iPSC-RPE from individuals without AMD. A more pronounced reduction in mitochondrial function and increased inflammatory markers was observed in CFH high-risk cells, irrespective of disease state. These results provide evidence for a previously unrecognized link between CFH and mitochondrial function that could contribute to RPE loss in AMD patients harboring the CFH high-risk genotype.
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Affiliation(s)
- Mara C. Ebeling
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - Zhaohui Geng
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rebecca J. Kapphahn
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - Heidi Roehrich
- Histology Core for Vision Research, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Sandra R. Montezuma
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
| | - James R. Dutton
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
- Correspondence: (J.R.D.); (D.A.F.); Tel.: +1-612-626-2762 (J.R.D.); +1-612-624-8267 (D.A.F.)
| | - Deborah A. Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; (M.C.E.); (R.J.K.); (S.R.M.)
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA;
- Correspondence: (J.R.D.); (D.A.F.); Tel.: +1-612-626-2762 (J.R.D.); +1-612-624-8267 (D.A.F.)
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Atilano SR, Udar N, Satalich TA, Udar V, Chwa M, Kenney MC. Low frequency mitochondrial DNA heteroplasmy SNPs in blood, retina, and [RPE+choroid] of age-related macular degeneration subjects. PLoS One 2021; 16:e0246114. [PMID: 33513185 PMCID: PMC7846006 DOI: 10.1371/journal.pone.0246114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 01/13/2021] [Indexed: 01/07/2023] Open
Abstract
Purpose Mitochondrial (mt) DNA damage is associated with age-related macular degeneration (AMD) and other human aging diseases. This study was designed to quantify and characterize mtDNA low-frequency heteroplasmy single nucleotide polymorphisms (SNPs) of three different tissues isolated from AMD subjects using Next Generation Sequencing (NGS) technology. Methods DNA was extracted from neural retina, [RPE+choroid] and blood from three deceased age-related macular degeneration (AMD) subjects. Entire mitochondrial genomes were analyzed for low-frequency heteroplasmy SNPs using NGS technology that independently sequenced both mtDNA strands. This deep sequencing method (average sequencing depth of 30,000; range 1,000–100,000) can accurately differentiate low-frequency heteroplasmy SNPs from DNA modification artifacts. Twenty-three ‘hot-spot’ heteroplasmy mtDNA SNPs were analyzed in 222 additional blood samples. Results Germline homoplasmy SNPs that defined mtDNA haplogroups were consistent in the three tissues of each subject. Analyses of SNPs with <40% heteroplasmy revealed the blood had significantly greater numbers of heteroplasmy SNPs than retina alone (p≤0.05) or retina+choroid combined (p = 0.008). Twenty-three ‘hot-spot’ mtDNA heteroplasmy SNPs were present, with three being non-synonymous (amino acid change). Four ‘hot-spot’ heteroplasmy SNPs (m.1120C>T, m.1284T>C, m.1556C>T, m.7256C>T) were found in additional samples (n = 222). Five heteroplasmy SNPs (m.4104A>G, m.5320C>T, m.5471G>A, m.5474A>G, m.5498A>G) declined with age. Two heteroplasmy SNPs (m.13095T>C, m.13105A>G) increased in AMD compared to Normal samples. In the heteroplasmy SNPs, very few transversion mutations (purine to pyrimidine or vice versa, associated with oxidative damage) were found and the majority were transition changes (purine to purine or pyrimidine to pyrimidine, associated with replication errors). Conclusion Within an individual, the blood, retina and [RPE+choroid] contained identical homoplasmy SNPs representing inherited germline mtDNA haplogroup. NGS methodology showed significantly more mtDNA heteroplasmy SNPs in blood compared to retina and [RPE+choroid], suggesting the latter tissues have substantial protection. Significantly higher heteroplasmy levels of m.13095T>C and m.13105A>G may represent potential AMD biomarkers. Finally, high levels of transition mutations suggest that accumulation of heteroplasmic SNPs may occur through replication errors rather than oxidative damage.
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Affiliation(s)
- Shari R. Atilano
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Nitin Udar
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Timothy A. Satalich
- Institute for Mathematical Behavioral Science, University of California Irvine, Irvine, CA, United States of America
| | - Viraat Udar
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
| | - M. Cristina Kenney
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, United States of America
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, United States of America
- * E-mail:
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Kim DH, Kim JH, Hwangbo H, Kim SY, Ji SY, Kim MY, Cha HJ, Park C, Hong SH, Kim GY, Park SK, Jeong JW, Kim MY, Choi YH, Lee H. Spermidine Attenuates Oxidative Stress-Induced Apoptosis via Blocking Ca 2+ Overload in Retinal Pigment Epithelial Cells Independently of ROS. Int J Mol Sci 2021; 22:ijms22031361. [PMID: 33572992 PMCID: PMC7866386 DOI: 10.3390/ijms22031361] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 01/26/2021] [Accepted: 01/26/2021] [Indexed: 02/06/2023] Open
Abstract
Retinal pigment epithelial (RPE) cells occupy the outer layer of the retina and perform various biological functions. Oxidative damage to RPE cells is a major risk factor for retinal degeneration that ultimately leads to vision loss. In this study, we investigated the role of spermidine in a hydrogen peroxide (H2O2)-induced oxidative stress model using human RPE cells. Our findings showed that 300 μM H2O2 increased cytotoxicity, apoptosis, and cell cycle arrest in the G2/M phase, whereas these effects were markedly suppressed by 10 μM spermidine. Furthermore, spermidine significantly reduced H2O2-induced mitochondrial dysfunction including mitochondrial membrane potential and mitochondrial activity. Although spermidine displays antioxidant properties, the generation of intracellular reactive oxygen species (ROS) upon H2O2 insult was not regulated by spermidine. Spermidine did suppress the increase in cytosolic Ca2+ levels resulting from endoplasmic reticulum stress in H2O2-stimulated human RPE cells. Treatment with a cytosolic Ca2+ chelator markedly reversed H2O2-induced cellular dysfunction. Overall, spermidine protected against H2O2-induced cellular damage by blocking the increase of intracellular Ca2+ independently of ROS. These results suggest that spermidine protects RPE cells from oxidative stress, which could be a useful treatment for retinal diseases.
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Affiliation(s)
- Da Hye Kim
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
| | - Jeong-Hwan Kim
- Research and Development Department, BGN CARE Co., Ltd., Busan 47195, Korea; (J.-H.K.); (S.-K.P.); (M.-Y.K.)
| | - Hyun Hwangbo
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
| | - So Young Kim
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
| | - Seon Yeong Ji
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
| | - Min Yeong Kim
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
| | - Hee-Jae Cha
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan 49267, Korea;
| | - Cheol Park
- Department of Molecular Biology, College of Natural Sciences, Dong-eui University, Busan 47340, Korea;
| | - Su Hyun Hong
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
| | - Gi-Young Kim
- Department of Marine Life Science, Jeju National University, Jeju 63243, Korea;
| | - Seh-Kwang Park
- Research and Development Department, BGN CARE Co., Ltd., Busan 47195, Korea; (J.-H.K.); (S.-K.P.); (M.-Y.K.)
- BGN Eye Clinic, Seoul 05551, Korea
| | | | - Mi-Young Kim
- Research and Development Department, BGN CARE Co., Ltd., Busan 47195, Korea; (J.-H.K.); (S.-K.P.); (M.-Y.K.)
| | - Yung Hyun Choi
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
- Correspondence: (Y.H.C.); (H.L.); Tel.: +82-51-890-3319 (Y.H.C.); +82-51-890-3315 (H.L.)
| | - Hyesook Lee
- Anti-Aging Research Center, Dong-eui University, Busan 47340, Korea; (D.H.K.); (H.H.); (S.Y.K.); (S.Y.J.); (M.Y.K.); (S.H.H.)
- Department of Biochemistry, Dong-eui University College of Korean Medicine, Busan 47227, Korea
- Correspondence: (Y.H.C.); (H.L.); Tel.: +82-51-890-3319 (Y.H.C.); +82-51-890-3315 (H.L.)
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Mitochondria: The Retina's Achilles' Heel in AMD. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1256:237-264. [PMID: 33848005 DOI: 10.1007/978-3-030-66014-7_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Strong experimental evidence from studies in human donor retinas and animal models supports the idea that the retinal pathology associated with age-related macular degeneration (AMD) involves mitochondrial dysfunction and consequent altered retinal metabolism. This chapter provides a brief overview of mitochondrial structure and function, summarizes evidence for mitochondrial defects in AMD, and highlights the potential ramifications of these defects on retinal health and function. Discussion of mitochondrial haplogroups and their association with AMD brings to light how mitochondrial genetics can influence disease outcome. As one of the most metabolically active tissues in the human body, there is strong evidence that disruption in key metabolic pathways contributes to AMD pathology. The section on retinal metabolism reviews cell-specific metabolic differences and how the metabolic interdependence of each retinal cell type creates a unique ecosystem that is disrupted in the diseased retina. The final discussion includes strategies for therapeutic interventions that target key mitochondrial pathways as a treatment for AMD.
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Badia A, Salas A, Duarri A, Ferreira-de-Souza B, Zapata MÁ, Fontrodona L, García-Arumí J. Transcriptomics analysis of Ccl2/Cx3cr1/Crb1 rd8 deficient mice provides new insights into the pathophysiology of progressive retinal degeneration. Exp Eye Res 2020; 203:108424. [PMID: 33373623 DOI: 10.1016/j.exer.2020.108424] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/16/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022]
Abstract
Chronic oxidative stress and immune dysregulation are key mechanisms involved in the pathogenesis of most retinal degenerative diseases, including age-related macular degeneration. The Ccl2-/-/Cx3cr1-/-/Crb1rd8/rd8 mouse model develops a progressive degeneration phenotype, with photoreceptor atrophy, drusen-like lesions or pigment alterations at an early age; however, the role of oxidative stress and immune function in the pathogenesis of the model is poorly understood. We performed a comprehensive characterization of the Ccl2-/-/Cx3cr1-/-/Crb1rd8/rd8 mouse to evaluate how these pathways influence pathogenesis. We generated a Ccl2-/-/Cx3cr1-/- double-knockout (DKO) mouse on a C57BL/6N background (with the rd8 mutation of the Crb1 gene), assessed its retina status and function during 9 months in both in vivo and post-mortem analysis, and performed a comprehensive transcriptomic analysis. DKOrd8 mice presented focal retinal lesions with increased infiltration of microglia and involvement of Müller cells. Lesions progressed to thinning of the photoreceptor nuclear layer, causing a loss in retinal function. Transcriptomics analysis revealed major differential expression of genes involved in oxidative stress and neuronal function, in particular genes related to the mitochondrial electron transport chain and antioxidant cellular response. Our results suggest that alterations in chemokine signaling combined with the rd8 mutation in Ccl2-/-/Cx3cr1-/-/Crb1rd8/rd8 mice involve early changes in several pathways associated with age-related macular degeneration, highlighting the relevance of these processes in the pathological retinal degeneration in the DKOrd8 model.
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Affiliation(s)
- Anna Badia
- Ophthalmology Research, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.
| | - Anna Salas
- Ophthalmology Research, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.
| | - Anna Duarri
- Ophthalmology Research, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.
| | | | - Miguel Ángel Zapata
- Ophthalmology Research, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.
| | - Laura Fontrodona
- Ophthalmology Research, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.
| | - José García-Arumí
- Ophthalmology Research, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain; Department of Ophthalmology, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
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Mano F, Sprehe N, Olsen TW. Association of Drusen Phenotype in Age-Related Macular Degeneration from Human Eye-Bank Eyes to Disease Stage and Cause of Death. Ophthalmol Retina 2020; 5:743-749. [PMID: 33227563 DOI: 10.1016/j.oret.2020.11.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To stage maculopathy, assess and quantify drusen, determine drusen subtype frequency, and compare subtypes with age-related macular degeneration (AMD) stage and cause of death using an eye-bank model of AMD. DESIGN Cross-sectional study. PARTICIPANTS Two thousand ninety-two human eyes from 1067 eye-bank donors, selected from a population at risk for AMD. METHODS We analyzed donor eye tissue images (2005-2020) using both the 4- and 9-step Minnesota Grading System (MGS), an AMD grading system for eye-bank eyes corresponding to the Age-Related Eye Disease Study classification. The 9-step MGS quantifies total drusen area, hyperpigmentation, and depigmentation. We analyzed reticular pseudodrusen (RPD), basal laminar drusen (BLD), and calcified drusen (CaD) frequency within this population and explored associations with AMD stage, donor age, gender, and cause of death. Statistical analyses were performed using Wilcoxon rank-sum and chi-square tests. Testing encompassed staging eye-bank eyes using MGS analysis. MAIN OUTCOME MEASURES Drusen subtype frequency associations with AMD stage and cause of death. RESULTS We detected RPD in 228 (13%), BLD in 131 (7%), and CaD in 84 (5%) of the examined eyes (n = 1777). All subtypes were associated with advanced AMD (RPD: odds ratio [OR], 3.4 [95% confidence interval (CI), 2.5-4.5; P < 0.0001]; BLD: OR, 2.2 [95% CI, 1.5-3.2; P < 0.0001]; and CaD: OR, 39.1 [95% CI, 16.8-91.0; P < 0.0001]). Only the RPD subtype was associated statistically with cardiovascular death when compared with those without cardiovascular death (48% vs. 32%; OR, 2.0 [95% CI, 1.4-2.9]; P = 0.0002). CONCLUSIONS In a large group of eye-bank eyes selected from a population at risk for AMD and graded using the 4-step and 9-step MGS, RPD, BLD, and especially CaD were associated strongly with advanced AMD. The RPD subtype was associated with a cardiovascular cause of death and may represent an ophthalmologic biomarker for cardiovascular disease.
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Affiliation(s)
- Fukutaro Mano
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota; Department of Ophthalmology, Kindai University, Osakasayama, Osaka, Japan
| | - Nicholas Sprehe
- Lions Eye Institute for Transplant and Research, Tampa Bay, Florida
| | - Timothy W Olsen
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota.
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Cheng YS, Linetsky M, Li H, Ayyash N, Gardella A, Salomon RG. 4-Hydroxy-7-oxo-5-heptenoic acid lactone can induce mitochondrial dysfunction in retinal pigmented epithelial cells. Free Radic Biol Med 2020; 160:719-733. [PMID: 32920040 PMCID: PMC7704664 DOI: 10.1016/j.freeradbiomed.2020.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/25/2020] [Accepted: 09/04/2020] [Indexed: 11/30/2022]
Abstract
Oxidation of docosahexaenoate (DHA)-containing phospholipids in the cell plasma membrane leads to release of the α,β-unsaturated aldehyde 4-hydroxy-7-oxo-5-heptenoic acid (HOHA) lactone which is capable of inducing retinal pigmented epithelial (RPE) cell dysfunction. Previously, HOHA lactone was shown to induce apoptosis and angiogenesis, and to activate the alternative complement pathway. RPE cells metabolize HOHA lactone through enzymatic conjugation with glutathione (GSH). Competing with this process is the adduction of HOHA lactone to protein lysyl residues generating 2-(ω-carboxyethyl)pyrrole (CEP) derivatives that have pathological relevance to age-related macular degeneration (AMD). We now find that HOHA lactone induces mitochondrial dysfunction. It decreases ATP levels, mitochondrial membrane potentials, enzymatic activities of mitochondrial complexes, depletes GSH and induces oxidative stress in RPE cells. The present study confirmed that pyridoxamine and other primary amines, which have been shown to scavenge γ-ketoaldehydes formed by carbohydrate or lipid peroxidation, are ineffective for scavenging the α,β-unsaturated aldehydes. Histidyl hydrazide (HH), that has both hydrazide and imidazole nucleophile functionalities, is an effective scavenger of HOHA lactone and it protects ARPE-19 cells against HOHA lactone-induced cytotoxicity. The HH α-amino group is not essential for this electrophile trapping activity. The Nα-acyl L-histidyl hydrazide derivatives with 2- to 7-carbon acyl groups with increasing lipophilicities are capable of maintaining the effectiveness of HH in protecting ARPE-19 cells against HOHA lactone toxicity, which potentially has therapeutic utility for treatment of age related eye diseases.
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Affiliation(s)
- Yu-Shiuan Cheng
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Mikhail Linetsky
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA; Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Haoting Li
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Naji Ayyash
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Anthony Gardella
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Robert G Salomon
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA; Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA.
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41
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Kaarniranta K, Uusitalo H, Blasiak J, Felszeghy S, Kannan R, Kauppinen A, Salminen A, Sinha D, Ferrington D. Mechanisms of mitochondrial dysfunction and their impact on age-related macular degeneration. Prog Retin Eye Res 2020; 79:100858. [PMID: 32298788 PMCID: PMC7650008 DOI: 10.1016/j.preteyeres.2020.100858] [Citation(s) in RCA: 268] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/21/2022]
Abstract
Oxidative stress-induced damage to the retinal pigment epithelium (RPE) is considered to be a key factor in age-related macular degeneration (AMD) pathology. RPE cells are constantly exposed to oxidative stress that may lead to the accumulation of damaged cellular proteins, lipids, nucleic acids, and cellular organelles, including mitochondria. The ubiquitin-proteasome and the lysosomal/autophagy pathways are the two major proteolytic systems to remove damaged proteins and organelles. There is increasing evidence that proteostasis is disturbed in RPE as evidenced by lysosomal lipofuscin and extracellular drusen accumulation in AMD. Nuclear factor-erythroid 2-related factor-2 (NFE2L2) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) are master transcription factors in the regulation of antioxidant enzymes, clearance systems, and biogenesis of mitochondria. The precise cause of RPE degeneration and the onset and progression of AMD are not fully understood. However, mitochondria dysfunction, increased reactive oxygen species (ROS) production, and mitochondrial DNA (mtDNA) damage are observed together with increased protein aggregation and inflammation in AMD. In contrast, functional mitochondria prevent RPE cells damage and suppress inflammation. Here, we will discuss the role of mitochondria in RPE degeneration and AMD pathology focused on mtDNA damage and repair, autophagy/mitophagy signaling, and regulation of inflammation. Mitochondria are putative therapeutic targets to prevent or treat AMD.
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Affiliation(s)
- Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland and Kuopio University Hospital, P.O. Box 1627, FI-70211, Kuopio, Finland.
| | - Hannu Uusitalo
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland and Tays Eye Centre, Tampere University Hospital, P.O.Box 2000, 33521 Tampere, Finland
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236, Lodz, Poland
| | - Szabolcs Felszeghy
- Department of Biomedicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Ram Kannan
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, 1355 San Pablo St, Los Angeles, CA, 90033, USA
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Debasish Sinha
- Glia Research Laboratory, Department of Ophthalmology, University of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA, PA 15224, USA; Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Room M035 Robert and Clarice Smith Bldg, 400 N Broadway, Baltimore, MD, 21287, USA
| | - Deborah Ferrington
- Department of Ophthalmology and Visual Neurosciences, 2001 6th St SE, University of Minnesota, Minneapolis, MN 55455, USA
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Do JY, Kim J, Kim MJ, Lee JY, Park SY, Yanai R, Lee IK, Park S, Park DH. Fursultiamine Alleviates Choroidal Neovascularization by Suppressing Inflammation and Metabolic Reprogramming. Invest Ophthalmol Vis Sci 2020; 61:24. [PMID: 33107903 PMCID: PMC7594589 DOI: 10.1167/iovs.61.12.24] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To assess the therapeutic effects of fursultiamine on choroidal neovascularization (CNV) through its modulation of inflammation and metabolic reprogramming in the retinal pigment epithelium (RPE). Methods The anti-angiogenic effects of fursultiamine were assessed by measuring vascular leakage and CNV lesion size in the laser-induced CNV mouse model. Inflammatory responses were evaluated by quantitative polymerase chain reaction, western blot, and ELISA in both CNV eye tissues and in vitro cell cultures using ARPE-19 cells or primary human RPE (hRPE) cells under lipopolysaccharide (LPS) treatment or hypoxia. Mitochondrial respiration was assessed by measuring oxygen consumption in ARPE-19 cells treated with LPS with or without fursultiamine, and lactate production was measured in ARPE-19 cells subjected to hypoxia with or without fursultiamine. Results In laser-induced CNV, fursultiamine significantly decreased vascular leakage and lesion size, as well as the numbers of both choroidal and retinal inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α. In LPS-treated ARPE-19 cells, fursultiamine decreased proinflammatory cytokine secretion and nuclear factor kappa B phosphorylation. Furthermore, fursultiamine suppressed LPS-induced upregulation of IL-6, IL-8, and monocyte chemoattractant protein-1 in a dose-dependent and time-dependent manner in primary hRPE cells. Interestingly, fursultiamine significantly enhanced mitochondrial respiration in the LPS-treated ARPE-19 cells. Additionally, fursultiamine attenuated hypoxia-induced aberrations, including lactate production and inhibitory phosphorylation of pyruvate dehydrogenase. Furthermore, fursultiamine attenuated hypoxia-induced VEGF secretion and mitochondrial fission in primary hRPE cells that were replicated in ARPE-19 cells. Conclusions Our findings show that fursultiamine is a viable putative therapeutic for neovascular age-related macular degeneration by modulating the inflammatory response and metabolic reprogramming by enhancing mitochondrial respiration in the RPE.
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Affiliation(s)
- Ji Yeon Do
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea
| | - Juhee Kim
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea
| | - Mi-Jin Kim
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea
| | - Jung Yi Lee
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea.,R&D Center, JD Bioscience, Inc., Gwangju, Republic of Korea
| | - So-Young Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Ryoji Yanai
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - In-Kyu Lee
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea.,Department of Internal Medicine, School of Medicine, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea
| | - Sungmi Park
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea
| | - Dong Ho Park
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea.,Department of Ophthalmology, School of Medicine, Kyungpook National University Hospital, Kyungpook National University, Daegu, Republic of Korea
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43
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Nita M, Grzybowski A. Interplay between reactive oxygen species and autophagy in the course of age-related macular degeneration. EXCLI JOURNAL 2020; 19:1353-1371. [PMID: 33192217 PMCID: PMC7658465 DOI: 10.17179/excli2020-2915] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022]
Abstract
Pathological biomolecules such as lipofuscin, methylglyoxal-modified proteins (the major precursors of advanced glycationend products), misfolding protein deposits and dysfunctional mitochondria are source of oxidative stress and act as strong autophagic stimulators in age-related macular degeneration. Disturbed autophagy accelerates progression of the disease, since it leads to retinal cells' death and activates inflammation by the interplay with the NLRP3 inflammasome complex. Vascular dysfunction and hypoxia, as well as circulating autoantibodies against autophagy regulators (anti-S100A9, anti-ANXA5, and anti-HSPA8, A9 and B4) compromise an autophagy-mediated mechanism as well. Metformin, the autophagic stimulator, may act as a senostatic drug to inhibit the senescent phenotype in the age-related macular degeneration. PGC-1α , Sirt1 and AMPK represent new therapeutic targets for interventions in this disease.
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Affiliation(s)
- Malgorzata Nita
- Domestic and Specialized Medicine Centre "Dilmed" Katowice, Poland
| | - Andrzej Grzybowski
- Department of Ophthalmolgy, Medical Faculty, University of Warmia and Mazury, Olsztyn, Poland.,Institute for Research in Ophthalmology, Poznań, Poland
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Jabbehdari S, Handa JT. Oxidative stress as a therapeutic target for the prevention and treatment of early age-related macular degeneration. Surv Ophthalmol 2020; 66:423-440. [PMID: 32961209 DOI: 10.1016/j.survophthal.2020.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/10/2020] [Accepted: 09/14/2020] [Indexed: 12/13/2022]
Abstract
Age-related macular degeneration, the leading cause of irreversible visual loss among older adults in developed countries, is a chronic, multifactorial, and progressive disease with the development of painless, central vision loss. Retinal pigment epithelial cell dysfunction is a core change in age-related macular degeneration that results from aging and the accumulated effects of genetic and environmental factors that, in part, is both caused by and leads to oxidative stress. In this review, we describe the role of oxidative stress, the cytoprotective oxidative stress pathways, and the impact of oxidative stress on critical cellular processes involved in age-related macular degeneration pathobiology. We also offer targeted therapy that may define how antioxidant therapy can either prevent or improve specific stages of age-related macular degeneration.
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Affiliation(s)
- Sayena Jabbehdari
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - James T Handa
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
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45
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Sreekumar PG, Kannan R. Mechanisms of protection of retinal pigment epithelial cells from oxidant injury by humanin and other mitochondrial-derived peptides: Implications for age-related macular degeneration. Redox Biol 2020; 37:101663. [PMID: 32768357 PMCID: PMC7767738 DOI: 10.1016/j.redox.2020.101663] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/18/2020] [Accepted: 07/26/2020] [Indexed: 02/06/2023] Open
Abstract
The mitochondrial-derived peptides (MDPs) are a new class of small open reading frame encoded polypeptides with pleiotropic properties. The prominent members are Humanin (HN) and small HN-like peptide (SHLP) 2, which encode 16S rRNA, while mitochondrial open reading frame of the twelve S c (MOTS-c) encodes 12S rRNA of the mitochondrial genome. While the multifunctional properties of HN and its analog 14-HNG have been well documented, their protective role in the retinal pigment epithelium (RPE)/retina has been investigated only recently. In this review, we have summarized the multiple effects of HN and its analogs, SHLP2 and MOTS-c in oxidatively stressed human RPE and the regulatory pathways of signaling, mitochondrial function, senescence, and inter-organelle crosstalk. Emphasis is given to the mitochondrial functions such as biogenesis, bioenergetics, and autophagy in RPE undergoing oxidative stress. Further, the potential use of HN and its analogs in the prevention of age-related macular degeneration (AMD) are also presented. In addition, the role of novel, long-acting HN elastin-like polypeptides in nanotherapy of AMD and other ocular diseases stemming from oxidative damage is discussed. It is expected MDPs will become a promising group of mitochondrial peptides with valuable therapeutic applications in the treatment of retinal diseases.
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Affiliation(s)
- Parameswaran G Sreekumar
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, CA, 90033, USA
| | - Ram Kannan
- The Stephen J. Ryan Initiative for Macular Research (RIMR), Doheny Eye Institute, Los Angeles, CA, 90033, USA; Stein Eye Institute, Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA.
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46
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Functional imaging of mitochondria in retinal diseases using flavoprotein fluorescence. Eye (Lond) 2020; 35:74-92. [PMID: 32709959 DOI: 10.1038/s41433-020-1110-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/01/2020] [Accepted: 07/16/2020] [Indexed: 12/27/2022] Open
Abstract
Mitochondria are critical for cellular energy production and homeostasis. Oxidative stress and associated mitochondrial dysfunction are integral components of the pathophysiology of retinal diseases, including diabetic retinopathy (DR), age-related macular degeneration, and glaucoma. Within mitochondria, flavoproteins are oxidized and reduced and emit a green autofluorescence when oxidized following blue light excitation. Recently, a noninvasive imaging device was developed to measure retinal flavoprotein fluorescence (FPF). Thus, oxidized FPF can act as a biomarker of mitochondrial dysfunction. This review article describes the literature surrounding mitochondrial FPF imaging in retinal disease. The authors describe the role of mitochondrial dysfunction in retinal diseases, experiments using FPF as a marker of mitochondrial dysfunction in vitro, the three generations of retinal FPF imaging devices, and the peer-reviewed publications that have examined FPF imaging in patients. Finally, the authors report their own study findings. Goals were to establish normative reference levels for FPF intensity and heterogeneity in healthy eyes, to compare between healthy eyes and eyes with diabetes and DR, and to compare across stages of DR. The authors present methods to calculate a patient's expected FPF values using baseline characteristics. FPF intensity and heterogeneity were elevated in diabetic eyes compared to age-matched control eyes, and in proliferative DR compared to diabetic eyes without retinopathy. In diabetic eyes, higher FPF heterogeneity was associated with poorer visual acuity. In conclusion, while current retinal imaging modalities frequently focus on structural features, functional mitochondrial imaging shows promise as a metabolically targeted tool to evaluate retinal disease.
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Loss of Complement Factor H impairs antioxidant capacity and energy metabolism of human RPE cells. Sci Rep 2020; 10:10320. [PMID: 32587311 PMCID: PMC7316856 DOI: 10.1038/s41598-020-67292-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/19/2020] [Indexed: 12/28/2022] Open
Abstract
Polymorphisms in the Complement Factor H (CFH) gene, coding for the Factor H protein (FH), can increase the risk for age-related macular degeneration (AMD). AMD-associated CFH risk variants, Y402H in particular, impair FH function leading to complement overactivation. Whether this alone suffices to trigger AMD pathogenesis remains unclear. In AMD, retinal homeostasis is compromised due to the dysfunction of retinal pigment epithelium (RPE) cells. To investigate the impact of endogenous FH loss on RPE cell balance, we silenced CFH in human hTERT-RPE1 cells. FH reduction led to accumulation of C3, at both RNA and protein level and increased RPE vulnerability toward oxidative stress. Mild hydrogen-peroxide exposure in combination with CFH knock-down led to a reduction of glycolysis and mitochondrial respiration, paralleled by an increase in lipid peroxidation, which is a key aspect of AMD pathogenesis. In parallel, cell viability was decreased. The perturbations of energy metabolism were accompanied by transcriptional deregulation of several glucose metabolism genes as well as genes modulating mitochondrial stability. Our data suggest that endogenously produced FH contributes to transcriptional and metabolic homeostasis and protects RPE cells from oxidative stress, highlighting a novel role of FH in AMD pathogenesis.
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EMT and EndMT: Emerging Roles in Age-Related Macular Degeneration. Int J Mol Sci 2020; 21:ijms21124271. [PMID: 32560057 PMCID: PMC7349630 DOI: 10.3390/ijms21124271] [Citation(s) in RCA: 137] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/12/2020] [Accepted: 06/14/2020] [Indexed: 02/06/2023] Open
Abstract
Epithelial–mesenchymal transition (EMT) and endothelial–mesenchymal transition (EndMT) are physiological processes required for normal embryogenesis. However, these processes can be hijacked in pathological conditions to facilitate tissue fibrosis and cancer metastasis. In the eye, EMT and EndMT play key roles in the pathogenesis of subretinal fibrosis, the end-stage of age-related macular degeneration (AMD) that leads to profound and permanent vision loss. Predominant in subretinal fibrotic lesions are matrix-producing mesenchymal cells believed to originate from the retinal pigment epithelium (RPE) and/or choroidal endothelial cells (CECs) through EMT and EndMT, respectively. Recent evidence suggests that EMT of RPE may also be implicated during the early stages of AMD. Transforming growth factor-beta (TGFβ) is a key cytokine orchestrating both EMT and EndMT. Investigations in the molecular mechanisms underpinning EMT and EndMT in AMD have implicated a myriad of contributing factors including signaling pathways, extracellular matrix remodelling, oxidative stress, inflammation, autophagy, metabolism and mitochondrial dysfunction. Questions arise as to differences in the mesenchymal cells derived from these two processes and their distinct mechanistic contributions to the pathogenesis of AMD. Detailed discussion on the AMD microenvironment highlights the synergistic interactions between RPE and CECs that may augment the EMT and EndMT processes in vivo. Understanding the differential regulatory networks of EMT and EndMT and their contributions to both the dry and wet forms of AMD can aid the development of therapeutic strategies targeting both RPE and CECs to potentially reverse the aberrant cellular transdifferentiation processes, regenerate the retina and thus restore vision.
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Macular impairment in mitochondrial diseases: a potential biomarker of disease severity. Sci Rep 2020; 10:8554. [PMID: 32444699 PMCID: PMC7244507 DOI: 10.1038/s41598-020-65482-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/05/2020] [Indexed: 11/08/2022] Open
Abstract
The high-energy demands of the retina are thought to contribute to its particular vulnerability to mitochondrial dysfunction. Photoreceptors are the cells with the higher oxygen consumption within the retina, and among these, the cones contain more mitochondria and have a higher energy demand than rods. A cohort of twenty-two patients with genetically-defined mitochondrial diseases (MDs) were enrolled to determine if the macula is functionally and anatomically impaired in these metabolic disorders. Visual acuity and fERG amplitude of patients with primary mitochondrial dysfunction were reduced compared to controls. Furthermore, SD-OCT layer segmentation showed a reduction of retinal and outer nuclear layer (ONL) volume in the macula of the patients. fERG amplitude showed a positive correlation with both ONL volume and thickness. A negative relationship was noted between fERG amplitude and disease severity assessed with Newcastle Mitochondrial Disease Adult Scale. In conclusion, MDs are associated with functional and anatomical alteration of macular cone system, characterized by its strong correlation with clinical disease severity suggesting a role as a potential biomarker of primary mitochondrial disorders.
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50
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Bulumulla C, Kularatne RN, Catchpole T, Takacs A, Christie A, Gilfoyle A, Nguyen TD, Stefan MC, Csaky KG. Investigating the Effect of Esterification on Retinal Pigment Epithelial Uptake Using Rhodamine B Derivatives. Transl Vis Sci Technol 2020; 9:18. [PMID: 32821515 PMCID: PMC7409196 DOI: 10.1167/tvst.9.6.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 03/12/2020] [Indexed: 11/25/2022] Open
Abstract
Purpose This study investigated the effects of esterification and increased lipophilicity on cellular penetration, accumulation and retention in ARPE-19-nic cells using ester functionalized rhodamine B dyes. Methods Rhodamine B was esterified to generate four dyes with increasing lipophilicity. Cellular uptake, retention and mitochondrial localization were investigated in vitro using ARPE-19-nic cells using direct intracellular and extracellular and mitochondrial fluorescence quantitation, confocal and high-resolution live cell imaging and co-localization with Mito-GFP. Results Cellular penetrance, mitochondrial accumulation, and retention of the esterified dyes were increased in ARPE-19-nic cells compared with the nonesterified parent dye by direct fluorescence quantitation. Imaging demonstrated intracellular accumulation was confined to mitochondria as confirmed by colocalization with Mito-GFP. Conclusions Esterification is an effective way to increase lipophilicity of a dye to improve cellular penetration of chemical entities. These observations may be key to improving retinal drug delivery for retinal pigment epithelium–based diseases. Translational Relevance Understanding the intracellular distribution of drugs into retinal pigment epithelium cells is a critical component for identifying potential therapies for retinal pigment epithelium–based diseases.
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Affiliation(s)
| | | | | | | | | | | | | | - Mihaela C Stefan
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA.,Department of Bioengineering, The University of Texas at Dallas, Richardson, TX, USA
| | - Karl G Csaky
- Retina Foundation of the Southwest, Dallas, TX, USA
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