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Li SY, Zhao N, Wei D, Pu N, Hao XN, Huang JM, Peng GH, Tao Y. Ferroptosis in the ageing retina: A malevolent fire of diabetic retinopathy. Ageing Res Rev 2024; 93:102142. [PMID: 38030091 DOI: 10.1016/j.arr.2023.102142] [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: 09/02/2023] [Revised: 11/08/2023] [Accepted: 11/21/2023] [Indexed: 12/01/2023]
Abstract
Ageing retina is prone to ferroptosis due to the iron accumulation and impaired efficiency of intracellular antioxidant defense system. Ferroptosis acts as a cell death modality that is characterized by the iron-dependent accumulation of lipid peroxidation. Ferroptosis is distinctively different from other types of regulated cell death (RCD) at the morphological, biochemical, and genetic levels. Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Its prevalence and severity increase progressively with age. Recent reports have shown that ferroptosis is implicated in the pathophysiology of DR. Under hyperglycemia condition, the endothelial cell and retinal pigment epithelium (RPE) cell will undergo ferroptosis, which contributes to the increased vascular permeability and the disrupted blood retinal barrier (BRB). The underlying etiology of DR can be attributed to the impaired BRB integrity and subsequent damages of the neurovascular units. In the absence of timely intervention, the compromised BRB can ultimately cause profound visual impairments. In particular, the ageing retina is vulnerable to ferroptosis, and hyperglycemia will accelerate the progression of this pathological process. In this article, we discuss the contributory role of ferroptosis in DR pathogenesis, and summarize recent therapeutic trials that targeting the ferroptosis. Further study on the ferroptosis mediated damage would enrich our knowledge of DR pathology, and promote the development of clinical treatment for this degenerative retinopathy.
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Affiliation(s)
- Si-Yu Li
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Na Zhao
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Dong Wei
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Ning Pu
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Xiao-Na Hao
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Jie-Min Huang
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Guang-Hua Peng
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China.
| | - Ye Tao
- Department of Physiology and Neurobiology, Laboratory of Visual Cell Differentiation and Regulation. School of Basic Medical Sciences, College of medicine, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China.
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Li C, Xiao C, Tao H, Tang X. Research progress of iron metabolism in retinal diseases. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:93-100. [PMID: 37846377 PMCID: PMC10577842 DOI: 10.1016/j.aopr.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 10/18/2023]
Abstract
Background Retinal diseases can lead to severe visual impairment and even blindness, but current treatments are limited. For precise targeted therapy, the pathophysiological mechanisms of the diseases still need to be further explored. Iron serves an essential role in many biological activities and helps maintain the function and morphology of the retina. The vision problems caused by retinal diseases are affecting more and more people, the study of iron metabolism in retinal diseases possesses great potential for clinical application. Main text Iron maintains a dynamic balance in the retina but in excess is toxic to the retina. Iron overload can lead to various pathological changes in the retina through oxidative stress, inflammation, cell death, angiogenesis and other pathways. It is therefore involved in the progression of retinal diseases such as age-related macular degeneration, glaucoma, diabetic retinopathy, retinitis pigmentosa, and hereditary iron overload. In recent years, iron chelators have been shown to be effective in the treatment of retinal diseases, but the exact mechanism is not yet fully understood. This question prompted further investigation into the specific mechanisms by which iron metabolism is involved in retinal disease. Conclusions This review summarizes iron metabolism processes in the retina and mechanistic studies of iron metabolism in the progression of retinal disease. It also highlights the therapeutic potential of iron chelators in retinal diseases.
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Affiliation(s)
- Cunzi Li
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Chunyu Xiao
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Hui Tao
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xianling Tang
- Department of Ophthalmology, Shenzhen Third People's Hospital, Shenzhen, China
- The First Affiliated Hospital of Harbin Medical University, Harbin, China
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Corraliza-Gomez M, Bendito B, Sandonis-Camarero D, Mondejar-Duran J, Villa M, Poncela M, Valero J, Sanchez D, Ganfornina MD. Dual role of Apolipoprotein D as long-term instructive factor and acute signal conditioning microglial secretory and phagocytic responses. Front Cell Neurosci 2023; 17:1112930. [PMID: 36779011 PMCID: PMC9908747 DOI: 10.3389/fncel.2023.1112930] [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: 11/30/2022] [Accepted: 01/10/2023] [Indexed: 01/28/2023] Open
Abstract
Microglial cells are recognized as very dynamic brain cells, screening the environment and sensitive to signals from all other cell types in health and disease. Apolipoprotein D (ApoD), a lipid-binding protein of the Lipocalin family, is required for nervous system optimal function and proper development and maintenance of key neural structures. ApoD has a cell and state-dependent expression in the healthy nervous system, and increases its expression upon aging, damage or neurodegeneration. An extensive overlap exists between processes where ApoD is involved and those where microglia have an active role. However, no study has analyzed the role of ApoD in microglial responses. In this work, we test the hypothesis that ApoD, as an extracellular signal, participates in the intercellular crosstalk sensed by microglia and impacts their responses upon physiological aging or damaging conditions. We find that a significant proportion of ApoD-dependent aging transcriptome are microglia-specific genes, and show that lack of ApoD in vivo dysregulates microglial density in mouse hippocampus in an age-dependent manner. Murine BV2 and primary microglia do not express ApoD, but it can be internalized and targeted to lysosomes, where unlike other cell types it is transiently present. Cytokine secretion profiles and myelin phagocytosis reveal that ApoD has both long-term pre-conditioning effects on microglia as well as acute effects on these microglial immune functions, without significant modification of cell survival. ApoD-triggered cytokine signatures are stimuli (paraquat vs. Aβ oligomers) and sex-dependent. Acute exposure to ApoD induces microglia to switch from their resting state to a secretory and less phagocytic phenotype, while long-term absence of ApoD leads to attenuated cytokine induction and increased myelin uptake, supporting a role for ApoD as priming or immune training factor. This knowledge should help to advance our understanding of the complex responses of microglia during aging and neurodegeneration, where signals received along our lifespan are combined with damage-triggered acute signals, conditioning both beneficial roles and limitations of microglial functions.
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Affiliation(s)
- Miriam Corraliza-Gomez
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain
| | - Beatriz Bendito
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain
| | - David Sandonis-Camarero
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain
| | - Jorge Mondejar-Duran
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain
| | - Miguel Villa
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain
| | - Marta Poncela
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain
| | - Jorge Valero
- Instituto de Neurociencias de Castilla y León, University of Salamanca, Salamanca, Spain
| | - Diego Sanchez
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain,Diego Sanchez,
| | - Maria D. Ganfornina
- Instituto de Biología y Genética Molecular, Unidad de Excelencia, University of Valladolid-CSIC, Valladolid, Spain,*Correspondence: Maria D. Ganfornina, ,
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Zhao T, Guo X, Sun Y. Iron Accumulation and Lipid Peroxidation in the Aging Retina: Implication of Ferroptosis in Age-Related Macular Degeneration. Aging Dis 2021; 12:529-551. [PMID: 33815881 PMCID: PMC7990372 DOI: 10.14336/ad.2020.0912] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 09/12/2020] [Indexed: 01/19/2023] Open
Abstract
Iron is an essential component in many biological processes in the human body. It is critical for the visual phototransduction cascade in the retina. However, excess iron can be toxic. Iron accumulation and reduced efficiency of intracellular antioxidative defense systems predispose the aging retina to oxidative stress-induced cell death. Age-related macular degeneration (AMD) is characterized by retinal iron accumulation and lipid peroxidation. The mechanisms underlying AMD include oxidative stress-mediated death of retinal pigment epithelium (RPE) cells and subsequent death of retinal photoreceptors. Understanding the mechanism of the disruption of iron and redox homeostasis in the aging retina and AMD is crucial to decipher these mechanisms of cell death and AMD pathogenesis. The mechanisms of retinal cell death in AMD are an area of active investigation; previous studies have proposed several types of cell death as major mechanisms. Ferroptosis, a newly discovered programmed cell death pathway, has been associated with the pathogenesis of several neurodegenerative diseases. Ferroptosis is initiated by lipid peroxidation and is characterized by iron-dependent accumulation. In this review, we provide an overview of the mechanisms of iron accumulation and lipid peroxidation in the aging retina and AMD, with an emphasis on ferroptosis.
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Affiliation(s)
- Tantai Zhao
- 1Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,2Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, China
| | - Xiaojian Guo
- 1Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,2Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, China
| | - Yun Sun
- 1Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,2Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, China
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5
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Courtois Y, Youale J, Behar-Cohen F, Picard É. [Iron and age-related macular degeneration: a new track]. Med Sci (Paris) 2020; 36:616-625. [PMID: 32614313 DOI: 10.1051/medsci/2020096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Iron has a fundamental role for cell physiology and especially in retina as a cofactor of many pathways of the visual transduction. A tightly regulated homeostasis avoids the accumulation of prooxidant and proinflammatory free iron. A dysfunction of iron retinal homeostasis is associated with many genetic or age-related degenerative diseases such as age-related macular degeneration (AMD). Here, we describe various mechanisms reported during AMD, enhanced by iron accumulation and its homeostasis dysregulation. We have investigated a local treatment with transferrin, the natural iron carrier, to control these pathological pathways and iron dysfunction, without side effects. Iron has a central role in pathogenesis of AMD and is a target for futures therapies.
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Affiliation(s)
- Yves Courtois
- Centre de Recherche des Cordeliers, Inserm, Sorbonne Université, USPC, Université Paris Descartes, Université Paris Diderot, UMRS1138, 15 rue de l'École de Médecine, F-75006 Paris, France
| | - Jenny Youale
- Centre de Recherche des Cordeliers, Inserm, Sorbonne Université, USPC, Université Paris Descartes, Université Paris Diderot, UMRS1138, 15 rue de l'École de Médecine, F-75006 Paris, France
| | - Francine Behar-Cohen
- Hôpital Cochin, AP-HP, Assistance Publique-Hôpitaux de Paris, 24 rue du Faubourg Saint-Jacques, 75014 Paris, France
| | - Émilie Picard
- Centre de Recherche des Cordeliers, Inserm, Sorbonne Université, USPC, Université Paris Descartes, Université Paris Diderot, UMRS1138, 15 rue de l'École de Médecine, F-75006 Paris, France
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6
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Stelling MP, Motta JM, Mashid M, Johnson WE, Pavão MS, Farrell NP. Metal ions and the extracellular matrix in tumor migration. FEBS J 2020; 286:2950-2964. [PMID: 31379111 DOI: 10.1111/febs.14986] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/22/2019] [Accepted: 07/06/2019] [Indexed: 12/15/2022]
Abstract
In this review, we explore the roles of divalent metal ions in structure and function within the extracellular matrix (ECM), specifically, their interaction with glycosaminoglycans (GAGs) during tumor progression. Metals and GAGs have been individually associated with physiological and pathological processes, however, their combined activities in regulating cell behavior and ECM remodeling have not been fully explored to date. During tumor progression, divalent metals and GAGs participate in central processes, such as cell migration and angiogenesis, either by modulating cell surface molecules, as well as soluble signaling factors. In addition, studies on metals and polysaccharides interactions have been of great value, as they provide structural information that can be correlated with function. Finally, we believe that understanding how metals are regulated in physiological and pathological conditions is paramount for the development of new treatment strategies, as well as diagnostic and exploratory tools.
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Affiliation(s)
- Mariana P Stelling
- Instituto Federal de Educacao, Educação, Ciência e Tecnologia do Rio de Janeiro, Brazil
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7
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Picard E, Daruich A, Youale J, Courtois Y, Behar-Cohen F. From Rust to Quantum Biology: The Role of Iron in Retina Physiopathology. Cells 2020; 9:cells9030705. [PMID: 32183063 PMCID: PMC7140613 DOI: 10.3390/cells9030705] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/07/2020] [Accepted: 03/09/2020] [Indexed: 12/24/2022] Open
Abstract
Iron is essential for cell survival and function. It is a transition metal, that could change its oxidation state from Fe2+ to Fe3+ involving an electron transfer, the key of vital functions but also organ dysfunctions. The goal of this review is to illustrate the primordial role of iron and local iron homeostasis in retinal physiology and vision, as well as the pathological consequences of iron excess in animal models of retinal degeneration and in human retinal diseases. We summarize evidence of the potential therapeutic effect of iron chelation in retinal diseases and especially the interest of transferrin, a ubiquitous endogenous iron-binding protein, having the ability to treat or delay degenerative retinal diseases.
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Affiliation(s)
- Emilie Picard
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Team 17, F-75006 Paris, France; (A.D.); (J.Y.); (Y.C.); (F.B.-C.)
- Correspondence: ; Tel.: +331-44-27-81-82
| | - Alejandra Daruich
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Team 17, F-75006 Paris, France; (A.D.); (J.Y.); (Y.C.); (F.B.-C.)
- Ophthalmology Department, Necker-Enfants Malades University Hospital, APHP, 75015 Paris, France
| | - Jenny Youale
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Team 17, F-75006 Paris, France; (A.D.); (J.Y.); (Y.C.); (F.B.-C.)
| | - Yves Courtois
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Team 17, F-75006 Paris, France; (A.D.); (J.Y.); (Y.C.); (F.B.-C.)
| | - Francine Behar-Cohen
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Team 17, F-75006 Paris, France; (A.D.); (J.Y.); (Y.C.); (F.B.-C.)
- Ophtalmopole, Cochin Hospital, AP-HP, Assistance Publique Hôpitaux de Paris, 24 rue du Faubourg Saint-Jacques, 75014 Paris, France
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8
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Abstract
Recent breakthroughs in our understanding of the molecular pathophysiology of retinal vascular disease have allowed us to specifically target pathological angiogenesis while minimizing damage to the neurosensory retina. This is perhaps best exemplified by the development of therapies targeting the potent angiogenic growth factor and vascular permeability mediator, vascular endothelial growth factor (VEGF). Anti-VEGF therapies, initially introduced for the treatment of choroidal neovascularization in patients with age-related macular degeneration, have also had a dramatic impact on the management of retinal vascular disease and are currently an indispensable component for the treatment of macular edema in patients with diabetic eye disease and retinal vein occlusions. Emerging evidence supports expanding the use of therapies targeting VEGF for the treatment of retinal neovascularization in patients with diabetic retinopathy and retinopathy of prematurity. However, VEGF is among a growing list of angiogenic and vascular hyperpermeability factors that promote retinal vascular disease. Many of these mediators are expressed in response to stabilization of a single family of transcription factors, the hypoxia-inducible factors (HIFs), that regulate the expression of these angiogenic stimulators. Here we review the basic principles driving pathological angiogenesis and discuss the current state of retinal anti-angiogenic pharmacotherapy as well as future directions.
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Affiliation(s)
- Yannis M Paulus
- Kellogg Eye Center, University of Michigan School of Medicine, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Akrit Sodhi
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N. Broadway St., Smith Building, 4039, Baltimore, MD, 21287, USA.
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Feenstra DJ, Seleci M, Denk N, Fauser S, Drawnel FM, Jayagopal A. Indocyanine green molecular angiography of choroidal neovascularization. Exp Eye Res 2018; 180:122-128. [PMID: 30582913 DOI: 10.1016/j.exer.2018.12.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/03/2018] [Accepted: 12/20/2018] [Indexed: 11/17/2022]
Abstract
Retinal diseases such as proliferative diabetic retinopathy and neovascular AMD are characterized by the formation of new blood vessels. Current imaging techniques such as fluorescein and ICG angiography help to identify areas of vascular leakage but are limited in their applicability due to their nonspecific nature. However, as new treatment paradigms emerge in an effort to have patient specific treatments, the development of new imaging techniques that are capable of identifying patient specific biomarkers will become crucial for the success of these approaches. In this study, we create and characterize an endoglin (CD105) targeted imaging probe that can be used for indocyanine green (ICG) molecular angiography. This anti-endoglin-ICG bioconjugate has a self-quenching "off-on" capacity to enable high contrast imaging of proliferative blood vessels at a molecular level in vivo. Using the laser CNV mouse model we demonstrate an approximate 3-fold increase in lesion visualization compared to non-targeting controls.
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Affiliation(s)
- Derrick J Feenstra
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd., Basel, Switzerland
| | - Muharrem Seleci
- Institute of Technical Chemistry, Leibniz University of Hanover, Hanover, Germany
| | - Nora Denk
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd., Basel, Switzerland
| | - Sascha Fauser
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd., Basel, Switzerland
| | - Faye M Drawnel
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd., Basel, Switzerland
| | - Ashwath Jayagopal
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd., Basel, Switzerland.
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10
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Chen L, Liu M, Luan Y, Liu Y, Zhang Z, Ma B, Liu X, Liu Y. BMP‑6 protects retinal pigment epithelial cells from oxidative stress‑induced injury by inhibiting the MAPK signaling pathways. Int J Mol Med 2018; 42:1096-1105. [PMID: 29767257 DOI: 10.3892/ijmm.2018.3675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 05/10/2018] [Indexed: 11/06/2022] Open
Abstract
Worldwide, neovascular age‑related macular degeneration (nAMD) is one of the most common causes of blindness in the elderly. In particular, degeneration of retinal pigment epithelial (RPE) cells represents the main pathological process in the development of nAMD, and oxidative stress serves a major role. The present study aimed to investigate the association between bone morphogenetic protein 6 (BMP‑6) and nAMD. BMP‑6 concentration was significantly reduced in patients with wet nAMD compared with in the control group. Furthermore, the present study investigated the protective effects of BMP‑6 on RPE cells following oxidative stress‑induced injury. Cell Counting Kit‑8 assay and terminal deoxynucleotidyl transferase dUTP nick‑end labeling staining demonstrated that BMP‑6 increased RPE cell viability, which was decreased following treatment with hydrogen peroxide (H2O2), and reduced H2O2‑induced apoptosis. In addition, western blotting revealed that BMP‑6 reversed the decrease in pro‑caspase‑3 levels and the dysregulation of the B‑cell lymphoma 2 (Bcl‑2)/Bcl‑2‑associated X protein (Bax) balance caused by H2O2. In addition, alterations in c‑Jun N‑terminal protein kinase (JNK) and p38 mitogen‑activated protein kinase (MAPK) expression were examined, and pretreatment with BMP‑6 was demonstrated to reduce H2O2‑induced activation of JNK and p38 MAPK. Conversely, the effects of BMP‑6 were attenuated by its inhibitor noggin. In conclusion, the present study demonstrated that BMP‑6 may protect RPE cells from oxidative stress injury to a certain extent, which may be associated with alterations in the MAPK signaling pathway. However, the specific mechanism of action underlying this effect requires further investigation. Overall, the present study laid a foundation for exploring novel nAMD treatment methods.
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Affiliation(s)
- Li Chen
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Ming Liu
- Department of Ophthalmology, The First Hospital of Xi'an, Xi'an, Shaanxi 710002, P.R. China
| | - Yan Luan
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Yingfei Liu
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Zhichao Zhang
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Bo Ma
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Xuan Liu
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Yong Liu
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
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11
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Koban Y, Sahin S, Boy F, Kara F. Elevated lipocalin-2 level in aqueous humor of patients with central retinal vein occlusion. Int Ophthalmol 2018; 39:981-986. [PMID: 29572586 DOI: 10.1007/s10792-018-0894-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/16/2018] [Indexed: 11/24/2022]
Abstract
PURPOSE To assess the concentrations of lipocalin-2 (LCN2) in the serum and the aqueous humor of patients with central retinal vein occlusion (CRVO). METHODS The concentrations of LCN2 in the serum and aqueous humor of 16 cataract patients and 16 patients with CRVO with macular edema were compared. Collection of aqueous samples was conducted in the operating theater under sterile conditions and just prior to intravitreal ranibizumab injection or cataract surgery. LCN2 levels in serum and aqueous humor samples were measured using a commercial kit (human lipocalin-2/NGAL PicoKine ELISA Kit, MyBioSource Inc., USA; Catalog No: MBS175829) based on standard sandwich enzyme-linked immunosorbent assay technology. RESULTS The concentrations of LCN2 in the aqueous humors of the CRVO group were higher than those of the control group (p = 0.021). There was no significant difference in serum LCN2 level between the two groups (p = 0.463). CONCLUSIONS Concentrations of LCN2 in aqueous humor are increased in CRVO. LCN2 may be part of a pro-catabolic phenotype, and it may play an important role in the dreaded complications of CRVO, such as macular edema, macular ischemia, and neovascularization, which lead to blindness.
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Affiliation(s)
- Yaran Koban
- Department of Ophthalmology, Faculty of Medicine, Kafkas University, Kars, Turkey.
| | - Seda Sahin
- Department of Biochemistry, Faculty of Medicine, Kafkas University, Kars, Turkey
| | - Fatih Boy
- Department of Biochemistry, Faculty of Medicine, Kafkas University, Kars, Turkey
| | - Fatih Kara
- Department of Biochemistry, Faculty of Medicine, Kafkas University, Kars, Turkey
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12
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Chaudhary K, Promsote W, Ananth S, Veeranan-Karmegam R, Tawfik A, Arjunan P, Martin P, Smith SB, Thangaraju M, Kisselev O, Ganapathy V, Gnana-Prakasam JP. Iron Overload Accelerates the Progression of Diabetic Retinopathy in Association with Increased Retinal Renin Expression. Sci Rep 2018; 8:3025. [PMID: 29445185 PMCID: PMC5813018 DOI: 10.1038/s41598-018-21276-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/31/2018] [Indexed: 12/31/2022] Open
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness among working-age adults. Increased iron accumulation is associated with several degenerative diseases. However, there are no reports on the status of retinal iron or its implications in the pathogenesis of DR. In the present study, we found that retinas of type-1 and type-2 mouse models of diabetes have increased iron accumulation compared to non-diabetic retinas. We found similar iron accumulation in postmortem retinal samples from human diabetic patients. Further, we induced diabetes in HFE knockout (KO) mice model of genetic iron overload to understand the role of iron in the pathogenesis of DR. We found increased neuronal cell death, vascular alterations and loss of retinal barrier integrity in diabetic HFE KO mice compared to diabetic wildtype mice. Diabetic HFE KO mouse retinas also exhibited increased expression of inflammation and oxidative stress markers. Severity in the pathogenesis of DR in HFE KO mice was accompanied by increase in retinal renin expression mediated by G-protein-coupled succinate receptor GPR91. In light of previous reports implicating retinal renin-angiotensin system in DR pathogenesis, our results reveal a novel relationship between diabetes, iron and renin-angiotensin system, thereby unraveling new therapeutic targets for the treatment of DR.
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Affiliation(s)
- Kapil Chaudhary
- Department of Medicine, Washington University, St. Louis, Missouri, USA
| | | | - Sudha Ananth
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Rajalakshmi Veeranan-Karmegam
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Amany Tawfik
- Dental College of Georgia, Augusta University, Augusta, Georgia, USA
| | | | - Pamela Martin
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Muthusamy Thangaraju
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Oleg Kisselev
- Department of Ophthalmology and Department of Biochemistry & Molecular Biology, Saint Louis University, St. Louis, Missouri, USA
| | - Vadivel Ganapathy
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Jaya P Gnana-Prakasam
- Department of Ophthalmology and Department of Biochemistry & Molecular Biology, Saint Louis University, St. Louis, Missouri, USA.
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13
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Siebold C, Yamashita T, Monnier PP, Mueller BK, Pasterkamp RJ. RGMs: Structural Insights, Molecular Regulation, and Downstream Signaling. Trends Cell Biol 2017; 27:365-378. [PMID: 28007423 PMCID: PMC5404723 DOI: 10.1016/j.tcb.2016.11.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 11/27/2016] [Accepted: 11/28/2016] [Indexed: 12/20/2022]
Abstract
Although originally discovered as neuronal growth cone-collapsing factors, repulsive guidance molecules (RGMs) are now known as key players in many fundamental processes, such as cell migration, differentiation, iron homeostasis, and apoptosis, during the development and homeostasis of many tissues and organs, including the nervous, skeletal, and immune systems. Furthermore, three RGMs (RGMa, RGMb/DRAGON, and RGMc/hemojuvelin) have been linked to the pathogenesis of various disorders ranging from multiple sclerosis (MS) to cancer and juvenile hemochromatosis (JHH). While the molecular details of these (patho)biological effects and signaling modes have long remained unknown, recent studies unveil several exciting and novel aspects of RGM processing, ligand-receptor interactions, and downstream signaling. In this review, we highlight recent advances in the mechanisms-of-action and function of RGM proteins.
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Affiliation(s)
- Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Philippe P Monnier
- Krembil Research Institute, 60 Leonard Street, M5T 2S8, Toronto, ONT, Canada
| | - Bernhard K Mueller
- Neuroscience Discovery Research, Abbvie, Knollstrasse 50, 67061 Ludwigshafen, Germany
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands.
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14
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Arjunan P, Gnanaprakasam JP, Ananth S, Romej MA, Rajalakshmi VK, Prasad PD, Martin PM, Gurusamy M, Thangaraju M, Bhutia YD, Ganapathy V. Increased Retinal Expression of the Pro-Angiogenic Receptor GPR91 via BMP6 in a Mouse Model of Juvenile Hemochromatosis. Invest Ophthalmol Vis Sci 2016; 57:1612-9. [PMID: 27046124 PMCID: PMC4824383 DOI: 10.1167/iovs.15-17437] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Hemochromatosis, an iron-overload disease, occurs as adult and juvenile types. Mutations in hemojuvelin (HJV), an iron-regulatory protein and a bone morphogenetic protein (BMP) coreceptor, underlie most of the juvenile type. Hjv(-/-) mice accumulate excess iron in retina and exhibit aberrant vascularization and angiomas. A succinate receptor, GPR91, is pro-angiogenic in retina. We hypothesized that Hjv(-/-) retinas have increased BMP signaling and increased GPR91 expression as the basis of angiomas. METHODS Expression of GPR91 was examined by qPCR, immunofluorescence, and Western blot in wild-type and Hjv(-/-) mouse retinas and pRPE cells. Influence of excess iron and BMP6 on GPR91 expression was investigated in ARPE-19 cells, and wild-type and Hjv(-/-) pRPE cells. Succinate was used to activate GPR91 and determine the effects of GPR91 signaling on VEGF expression. Signaling of BMP6 was studied by the expression of Smad1/5/8 and pSmad4, and the BMP-target gene Id1. The interaction of pSmad4 with GPR91 promoter was studied by ChIP. RESULTS Expression of GPR91 was higher in Hjv(-/-) retinas and RPE than in wild-type counterparts. Unexpectedly, BMP signaling was increased, not decreased, in Hjv(-/-) retinas and RPE. Bone morphogenetic protein 6 induced GPR91 in RPE, suggesting that increased BMP signaling in Hjv(-/-) retinas was likely responsible for GPR91 upregulation. Exposure of RPE to excess iron and succinate as well as BMP6 and succinate increased VEGF expression. Bone morphogenetic protein 6 promoted the interaction of pSmad4 with GPR91 promoter in RPE. CONCLUSIONS G-protein-coupled receptor 91 is a BMP6 target and Hjv deletion enhances BMP signaling in retina, thus underscoring a role for excess iron and hemochromatosis in abnormal retinal vascularization.
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Affiliation(s)
- Pachiappan Arjunan
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States 2Department of Periodontics, Georgia Regents University, Augusta, Georgia, United States
| | - Jaya P Gnanaprakasam
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Sudha Ananth
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Michelle A Romej
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | | | - Puttur D Prasad
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Pamela M Martin
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Mariappan Gurusamy
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Muthusamy Thangaraju
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States
| | - Yangzom D Bhutia
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States 3Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, United States
| | - Vadivel Ganapathy
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, Georgia, United States 3Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, United States
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15
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Functional role of inorganic trace elements in angiogenesis—Part I: N, Fe, Se, P, Au, and Ca. Crit Rev Oncol Hematol 2015; 96:129-42. [DOI: 10.1016/j.critrevonc.2015.05.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 04/15/2015] [Accepted: 05/12/2015] [Indexed: 01/08/2023] Open
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