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Faizi HS, Nasiri MI, Wu Y, Mishra D, Donnelly RF, Minhas MU, Vora LK, Singh Thakur RR. Deferasirox nanosuspension loaded dissolving microneedles for ocular drug delivery. Int J Pharm 2024; 664:124614. [PMID: 39168286 DOI: 10.1016/j.ijpharm.2024.124614] [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: 06/17/2024] [Revised: 08/16/2024] [Accepted: 08/17/2024] [Indexed: 08/23/2024]
Abstract
Deferasirox (DFS) is an oral iron chelator that is employed in retinal ailments as a neuroprotectant against retinal injury and thus has utility in treating disorders such as excitoneurotoxicity and age-related macular degeneration (AMD). However, the conventional oral route of administration can present several disadvantages, e.g., the need for more frequent dosing and the first-pass effect. Microneedles (MNs) are minimally invasive systems that can be employed for intrascleral drug delivery without pain and can advantageously replace intravitreal injections therapy (IVT) as well as conventional oral routes of delivery for DFS. In this study, DFS was formulated into a nanosuspension (NS) through wet media milling employing PVA as a stabilizer, which was successfully loaded into polymeric dissolving MNs. DFS exhibited a 4-fold increase in solubility in DFS-NS compared to that of pure DFS. Moreover, the DFS-NSs exhibited excellent short-term stability and enhanced thermal stability, as confirmed through thermogravimetric analysis (TGA) studies. The mechanical characterization of the DFS-NS loaded ocular microneedles (DFS-NS-OcMNs), revealed that the system was sufficiently strong for effective scleral penetration. Optical coherence tomography (OCT) images confirmed the insertion of 81.23 ± 7.35 % of the total height of the MN arrays into full-thickness porcine sclera. Scleral deposition studies revealed 64 % drug deposition after just 5 min of insertion from DFS-NS-loaded ocular microneedles (OcMNs), which was almost 5 times greater than the deposition from pure DFS-OcMNs. Furthermore, both DFS and DFS-NS-OcMN exhibited remarkable cell viability when evaluated on human retinal pigment (ARPE) cells, suggesting their safety and appropriateness for use in the human eye. Therefore, loading DFS-NS into novel MN devices is a promising technique for effectively delivering DFS to the posterior segment of the eye in a minimally invasive manner.
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Affiliation(s)
- Hafsa Shahid Faizi
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom; College of Pharmacy, University of Sargodha, University Road, Sargodha, Punjab 40100, Pakistan
| | - Muhammad Iqbal Nasiri
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom; Faculty of Pharmacy, Plot No 4, Hamdard University, Park link Rd, Chak Shahzad, Islamabad Capital Territory, Pakistan
| | - Yu Wu
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom
| | - Deepakkumar Mishra
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom
| | - Ryan F Donnelly
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom
| | - Muhammad Usman Minhas
- College of Pharmacy, University of Sargodha, University Road, Sargodha, Punjab 40100, Pakistan
| | - Lalitkumar K Vora
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom.
| | - Raghu Raj Singh Thakur
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom.
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Xu Y, Huang S, Zhou S, Wang X, Wei M, Chen X, Zong R, Lin X, Li S, Liu Z, Chen Q. Iron Chelator Deferiprone Restores Iron Homeostasis and Inhibits Retinal Neovascularization in Experimental Neovascular Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2024; 65:5. [PMID: 39093298 PMCID: PMC11305424 DOI: 10.1167/iovs.65.10.5] [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: 05/10/2024] [Accepted: 07/10/2024] [Indexed: 08/04/2024] Open
Abstract
Purpose Retinal neovascularization is a significant feature of advanced age-related macular degeneration (AMD) and a major cause of blindness in patients with AMD. However, the underlying mechanism of this pathological neovascularization remains unknown. Iron metabolism has been implicated in various biological processes. This study was conducted to investigate the effects of iron metabolism on retinal neovascularization in neovascular AMD (nAMD). Methods C57BL/6J and very low-density lipoprotein receptor (VLDLR) knockout (Vldlr-/-) mice, a murine model of nAMD, were used in this study. Bulk-RNA sequencing was used to identify differentially expressed genes. Western blot analysis was performed to test the expression of proteins. Iron chelator deferiprone (DFP) was administrated to the mice by oral gavage. Fundus fluorescein angiography was used to evaluate retinal vascular leakage. Immunofluorescence staining was used to detect macrophages and iron-related proteins. Results RNA sequencing (RNA-seq) results showed altered transferrin expression in the retina and RPE of Vldlr-/- mice. Disrupted iron homeostasis was observed in the retina and RPE of Vldlr-/- mice. DFP mitigated iron overload and significantly reduced retinal neovascularization and vascular leakage. In addition, DFP suppressed the inflammation in Vldlr-/- retinas. The reduced signals of macrophages were observed at sites of neovascularization in the retina and RPE of Vldlr-/- mice after DFP treatment. Further, the IL-6/JAK2/STAT3 signaling pathway was activated in the retina and RPE of Vldlr-/- mice and reversed by DFP treatment. Conclusions Disrupted iron metabolism may contribute to retinal neovascularization in nAMD. Restoring iron homeostasis by DFP could be a potential therapeutic approach for nAMD.
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Affiliation(s)
- Yuan Xu
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Shiya Huang
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Shengmei Zhou
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Xin Wang
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Mingyan Wei
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Xiaodong Chen
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Rongrong Zong
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Xiang Lin
- Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, Fujian, China
| | - Shiying Li
- Department of Ophthalmology, the First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Zuguo Liu
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
- Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, Fujian, China
| | - Qian Chen
- Xiamen University affiliated Xiamen Eye Center, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
- Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, Fujian, China
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Rayatpour A, Foolad F, Javan M. Deferiprone promoted remyelination and functional recovery through enhancement of oligodendrogenesis in experimental demyelination animal model. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-03314-1. [PMID: 39046528 DOI: 10.1007/s00210-024-03314-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 07/17/2024] [Indexed: 07/25/2024]
Abstract
Remyelination refers to myelin regeneration, which reestablishes metabolic supports to axons. However, remyelination often fails in multiple sclerosis (MS), leading to chronic demyelination and axonal degeneration. Therefore, pharmacological approaches toward enhanced remyelination are highly demanded. Recently, deferiprone (DFP) was reported to exert neuroprotective effects, besides its iron-chelating ability. Since DFP exerts protective effects through various mechanisms, which share several factors with myelin formation process, we aimed to investigate the effects of DFP treatment on remyelination. Focal demyelination was induced by injection of lysolecithin, into the optic nerve of male C57BL/6J mice. The animals were treated with DFP/vehicle, starting from day 7 and continued during the myelin repair period. Histopathological, electrophysiological, and behavioral studies were used to evaluate the outcomes. Results showed that DFP treatment enhanced remyelination, decreased g-ratio and increased myelin thickness. At the mechanistic level, DFP enhanced oligodendrogenesis and ameliorated gliosis during the remyelination period. Furthermore, our results indicated that enhanced remyelination led to functional recovery as evaluated by the electrophysiological and behavioral tests. Even though the exact molecular mechanisms by which DFP-enhanced myelin repair remain to be elucidated, these results raise the possibility of using deferiprone as a therapeutic agent for remyelination therapy in MS.
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Affiliation(s)
- Atefeh Rayatpour
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- Institute for Brain and Cognition, Tarbiat Modares University, Tehran, Iran
| | - Forough Foolad
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- Institute for Brain and Cognition, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Javan
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
- Institute for Brain and Cognition, Tarbiat Modares University, Tehran, Iran.
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
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Huang H, Zeng J, Yu X, Du H, Wen C, Mao Y, Tang H, Kuang X, Liu W, Yu H, Liu H, Li B, Long C, Yan J, Shen H. Establishing chronic models of age-related macular degeneration via long-term iron ion overload. Am J Physiol Cell Physiol 2024; 326:C1367-C1383. [PMID: 38406826 DOI: 10.1152/ajpcell.00532.2023] [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: 10/12/2023] [Revised: 01/26/2024] [Accepted: 02/14/2024] [Indexed: 02/27/2024]
Abstract
Age-related macular degeneration (AMD) is characterized by the degenerative senescence in the retinal pigment epithelium (RPE) and photoreceptors, which is accompanied by the accumulation of iron ions in the aging retina. However, current models of acute oxidative stress are still insufficient to simulate the gradual progression of AMD. To address this, we established chronic injury models by exposing the aRPE-19 cells, 661W cells, and mouse retina to iron ion overload over time. Investigations at the levels of cell biology and molecular biology were performed. It was demonstrated that long-term treatment of excessive iron ions induced senescence-like morphological changes, decreased cell proliferation, and impaired mitochondrial function, contributing to apoptosis. Activation of the mitogen-activated protein kinase (MAPK) pathway and the downstream molecules were confirmed both in the aRPE-19 and 661W cells. Furthermore, iron ion overload resulted in dry AMD-like lesions and decreased visual function in the mouse retina. These findings suggest that chronic exposure to overloading iron ions plays a significant role in the pathogenesis of retinopathy and provide a potential model for future studies on AMD.NEW & NOTEWORTHY To explore the possibility of constructing reliable research carriers on age-related macular degeneration (AMD), iron ion overload was applied to establish models in vitro and in vivo. Subsequent investigations into cellular physiology and molecular biology confirmed the presence of senescence in these models. Through this study, we hope to provide a better option of feasible methods for future researches into AMD.
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Affiliation(s)
- Hao Huang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
- Department of Ophthalmology, Zhuzhou Hospital Affiliated to Xiangya School of Medicine, Central South University, Zhuzhou, People's Republic of China
| | - Jingshu Zeng
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Xinyue Yu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Han Du
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Chaojuan Wen
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Yan Mao
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Han Tang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Xielan Kuang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
- Biobank of Eye, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Wei Liu
- Department of Ophthalmology, Zhuzhou Hospital Affiliated to Xiangya School of Medicine, Central South University, Zhuzhou, People's Republic of China
| | - Huan Yu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Huijun Liu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
- Eye Fundus Department, Affiliated Aier Eye Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Bowen Li
- Eye Center of Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Chongde Long
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Jianhua Yan
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Huangxuan Shen
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
- Biobank of Eye, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
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5
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Dvoriantchikova G, Fleishaker M, Ivanov D. Molecular mechanisms of NMDA excitotoxicity in the retina. Sci Rep 2023; 13:18471. [PMID: 37891222 PMCID: PMC10611720 DOI: 10.1038/s41598-023-45855-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 10/25/2023] [Indexed: 10/29/2023] Open
Abstract
NMDA excitotoxicity, as a part of glutamate excitotoxicity, has been proposed to contribute significantly to many retinal diseases. Therefore, understanding mechanisms of NMDA excitotoxicity will provide further insight into the mechanisms of many retinal diseases. To study mechanisms of NMDA excitotoxicity in vivo, we used an animal model in which NMDA (20 mM, 2 µL) was injected into the vitreous of mice. We also used high-throughput expression profiling, various animals with reduced expression of target genes, and animals treated with the oral iron chelator deferiprone. We found that the expression of many genes involved in inflammation, programmed cell death, free radical production, oxidative stress, and iron and calcium signaling was significantly increased 24 h after NMDA treatment. Meanwhile, decreased activity of the pro-inflammatory TNF signaling cascade and decreased levels of ferrous iron (Fe2+, required for free radical production) led to significant neuroprotection in NMDA-treated retinas. Since increased TNF signaling activity and high Fe2+ levels trigger regulated necrosis, which, in turn, lead to inflammation, we proposed an important role in NMDA excitotoxicity of a positive feedback loop in which regulated necrosis promotes inflammation, which subsequently triggers regulated necrosis.
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Affiliation(s)
- Galina Dvoriantchikova
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10Th Ave, Miami, FL, 33136, USA
| | - Michelle Fleishaker
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10Th Ave, Miami, FL, 33136, USA
| | - Dmitry Ivanov
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10Th Ave, Miami, FL, 33136, USA.
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
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6
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Zhao Y, Li Q, Jian W, Han X, Zhang Y, Zeng Y, Liu R, Wang Q, Song Q. Protective benefits of salvianic acid A against retinal iron overload by inhibition of ferroptosis. Biomed Pharmacother 2023; 165:115140. [PMID: 37429233 DOI: 10.1016/j.biopha.2023.115140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/01/2023] [Accepted: 07/07/2023] [Indexed: 07/12/2023] Open
Abstract
BACKGROUND Both the accumulation of reactive oxygen species (ROS) and iron overload are significant variables that enhance the incidence of photoreceptor cell death and retinal degeneration. The discovery of ferroptosis, which is characterized by iron-dependent lipid peroxidation, has led to a new perspective on how retinal degeneration develops. As a natural phenolic acid, salvianic acid A (SAA) from Salvia miltiorrhiza has promise in treating eye diseases. The purpose of this research was to learn more about SAA and its function in the development of iron-overload-induced retinal degeneration. METHODS Models of iron overload in Kunming mice and the murine photoreceptor cell line 661 W were established, then the protective and antiferroptotic properties of SAA were assessed in vivo and in vitro. RESULTS Biochemical and histopathological findings on the retina confirmed that SAA successfully alleviated retinal injury. In photoreceptor cells, iron overload caused cell death, mitochondrial dysfunction, ROS generation, and iron deposition. Salvianic acid A relieved lipid peroxidation and decreased iron accumulation by modulating Acyl-CoA synthetase long-chain family member 4, glutathione peroxidase 4, solute carrier family 7 member 11, and iron-metabolism-related proteins. The mitochondrial morphology suggests that the retinal protective effect of SAA is mediated via antiferroptotic action. CONCLUSION Ferroptosis plays an important role in the pathogenesis of iron-overload-induced retinal degeneration. New roles of SAA in ferroptosis prevention via iron deposit inhibition, lipid peroxidation inhibition, and mitochondrial dysfunction reduction, were identified.
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Affiliation(s)
- Ying Zhao
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu 610084 Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection with TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Guangzhou Ineye Vision Health Innovation Institute, No.2 Fenghuang 3rd Road, Guangzhou 510555 Guangdong, China
| | - Qiang Li
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu 610084 Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection with TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Guangzhou Ineye Vision Health Innovation Institute, No.2 Fenghuang 3rd Road, Guangzhou 510555 Guangdong, China
| | - Wenyuan Jian
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu 610084 Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection with TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Guangzhou Ineye Vision Health Innovation Institute, No.2 Fenghuang 3rd Road, Guangzhou 510555 Guangdong, China
| | - Xue Han
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, No.326 Xinshi South Road, Shijiazhuang 050200 Hebei, China
| | - Yuanyuan Zhang
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, No.326 Xinshi South Road, Shijiazhuang 050200 Hebei, China
| | - Yan Zeng
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China
| | - Rong Liu
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China
| | - Qun Wang
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu 610084 Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection with TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China
| | - Qiongtao Song
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu 610084 Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection with TCM, No.37 Twelve Bridge Road, Chengdu 610075 Sichuan, China; Guangzhou Ineye Vision Health Innovation Institute, No.2 Fenghuang 3rd Road, Guangzhou 510555 Guangdong, China.
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Zhang KR, Jankowski CSR, Marshall R, Nair R, Más Gómez N, Alnemri A, Liu Y, Erler E, Ferrante J, Song Y, Bell BA, Baumann BH, Sterling J, Anderson B, Foshe S, Roof J, Fazelinia H, Spruce LA, Chuang JZ, Sung CH, Dhingra A, Boesze-Battaglia K, Chavali VRM, Rabinowitz JD, Mitchell CH, Dunaief JL. Oxidative stress induces lysosomal membrane permeabilization and ceramide accumulation in retinal pigment epithelial cells. Dis Model Mech 2023; 16:dmm050066. [PMID: 37401371 PMCID: PMC10399446 DOI: 10.1242/dmm.050066] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 06/23/2023] [Indexed: 07/05/2023] Open
Abstract
Oxidative stress has been implicated in the pathogenesis of age-related macular degeneration, the leading cause of blindness in older adults, with retinal pigment epithelium (RPE) cells playing a key role. To better understand the cytotoxic mechanisms underlying oxidative stress, we used cell culture and mouse models of iron overload, as iron can catalyze reactive oxygen species formation in the RPE. Iron-loading of cultured induced pluripotent stem cell-derived RPE cells increased lysosomal abundance, impaired proteolysis and reduced the activity of a subset of lysosomal enzymes, including lysosomal acid lipase (LIPA) and acid sphingomyelinase (SMPD1). In a liver-specific Hepc (Hamp) knockout murine model of systemic iron overload, RPE cells accumulated lipid peroxidation adducts and lysosomes, developed progressive hypertrophy and underwent cell death. Proteomic and lipidomic analyses revealed accumulation of lysosomal proteins, ceramide biosynthetic enzymes and ceramides. The proteolytic enzyme cathepsin D (CTSD) had impaired maturation. A large proportion of lysosomes were galectin-3 (Lgals3) positive, suggesting cytotoxic lysosomal membrane permeabilization. Collectively, these results demonstrate that iron overload induces lysosomal accumulation and impairs lysosomal function, likely due to iron-induced lipid peroxides that can inhibit lysosomal enzymes.
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Affiliation(s)
- Kevin R. Zhang
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Connor S. R. Jankowski
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Rayna Marshall
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rohini Nair
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Néstor Más Gómez
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ahab Alnemri
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yingrui Liu
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elizabeth Erler
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Julia Ferrante
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ying Song
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brent A. Bell
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bailey H. Baumann
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jacob Sterling
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brandon Anderson
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sierra Foshe
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer Roof
- CHOP-PENN Proteomics Core Facility, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
| | - Hossein Fazelinia
- CHOP-PENN Proteomics Core Facility, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
| | - Lynn A. Spruce
- CHOP-PENN Proteomics Core Facility, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
| | - Jen-Zen Chuang
- Department of Ophthalmology, Weill Cornell Medicine, New York, NY 10065, USA
- Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Ching-Hwa Sung
- Department of Ophthalmology, Weill Cornell Medicine, New York, NY 10065, USA
- Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Venkata R. M. Chavali
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joshua D. Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Claire H. Mitchell
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joshua L. Dunaief
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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8
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Dvoriantchikova G, Adis E, Lypka K, Ivanov D. Various Forms of Programmed Cell Death Are Concurrently Activated in the Population of Retinal Ganglion Cells after Ischemia and Reperfusion. Int J Mol Sci 2023; 24:9892. [PMID: 37373037 DOI: 10.3390/ijms24129892] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Retinal ischemia-reperfusion (IR)-which ultimately results in retinal ganglion cell (RGC) death-is a common cause of visual impairment and blindness worldwide. IR results in various types of programmed cell death (PCD), which are of particular importance since they can be prevented by inhibiting the activity of their corresponding signaling cascades. To study the PCD pathways in ischemic RGCs, we used a mouse model of retinal IR and a variety of approaches including RNA-seq analysis, knockout animals, and animals treated with an iron chelator. In our RNA-seq analysis, we utilized RGCs isolated from retinas 24 h after IR. In ischemic RGCs, we found increased expression of many genes that regulate apoptosis, necroptosis, pyroptosis, oxytosis/ferroptosis, and parthanatos. Our data indicate that genetic ablation of death receptors protects RGCs from IR. We showed that the signaling cascades regulating ferrous iron (Fe2+) metabolism undergo significant changes in ischemic RGCs, leading to retinal damage after IR. This data suggests that the activation of death receptors and increased Fe2+ production in ischemic RGCs promote the simultaneous activation of apoptosis, necroptosis, pyroptosis, oxytosis/ferroptosis, and parthanatos pathways. Thus, a therapy is needed that concurrently regulates the activity of the multiple PCD pathways to reduce RGC death after IR.
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Affiliation(s)
- Galina Dvoriantchikova
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Emily Adis
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Karin Lypka
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Dmitry Ivanov
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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9
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Chen Y, Deng Y, Chen L, Huang Z, Yan Y, Huang Z. miR-16-5p Regulates Ferroptosis by Targeting SLC7A11 in Adriamycin-Induced Ferroptosis in Cardiomyocytes. J Inflamm Res 2023; 16:1077-1089. [PMID: 36941983 PMCID: PMC10024494 DOI: 10.2147/jir.s393646] [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: 10/16/2022] [Accepted: 02/21/2023] [Indexed: 03/16/2023] Open
Abstract
Introduction Adriamycin (ADR) is commonly used in tumor chemotherapy, but its nonreversible cardiotoxicity severely hampers its clinical application. Ferroptosis is an implicated cause of ADR-induced injury. However, the underlying molecular mechanisms remain poorly understood. This study explored whether ferroptosis is a pivotal pathogenic pathway underlying ADR-induced cardiotoxicity and the possible molecular mechanisms involved. Methods In vivo and in vitro experimental models were used to study the mechanism of ADR-mediated ferroptosis. Ferroptosis levels were examined in mice and human/rat cardiomyocytes. Mechanistically, the expression levels of SLC7A11 and related miRNAs were examined. Bioinformatics prediction and luciferase reporter assays were used to verify the potential interaction between miR-16-5p and SLC7A11. The biological functions and interaction of SLC7A11 and miR-16-5p were investigated in vivo and in vitro. Results Our study observed that ADR treatment significantly increased ferroptosis levels in vivo and in vitro. Ferroptosis-related pharmacological interventions further confirmed these results. Our data displayed that the SLC7A11 level was significantly decreased in cardiac tissues and cells, while an increased expression level of miR-16-5p was observed. Moreover, upregulation of SLC7A1 and inhibition of miR-16-5p attenuated ADR-induced cardiomyocyte ferroptosis injury. Interactive rescue experiments showed that the protective effects of miR-16-5p inhibition on ADR-induced cardiomyocyte injury were blocked by SLC7A11 knockdown. Discussion Based on these findings, targeting miR-16-5p could partially reverse the ADR-induced cardiotoxicity by rescuing the SLC7A11 to attenuate ferroptosis. This study presents a pre-clinical basis to identify miR-16-5p/SLC7A11 as a potential treatment target for ADR-induced cardiotoxicity.
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Affiliation(s)
- Yongquan Chen
- Department of Cardiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
| | - Yecheng Deng
- Department of Cardiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
| | - Linghua Chen
- Department of Cardiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
| | - Ziyao Huang
- Department of Cardiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
| | - Yi Yan
- Department of Cardiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
| | - Zhaoqi Huang
- Department of Cardiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
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10
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CHAC1 as a Novel Contributor of Ferroptosis in Retinal Pigment Epithelial Cells with Oxidative Damage. Int J Mol Sci 2023; 24:ijms24021582. [PMID: 36675091 PMCID: PMC9861460 DOI: 10.3390/ijms24021582] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/31/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the elderly population. With aging and the accumulated effects of environmental stress, retinal pigment epithelial (RPE) cells are particularly susceptible to oxidative damage, which can lead to retinal degeneration. However, the underlying molecular mechanisms of how RPE responds and progresses under oxidative damage are still largely unknown. Here, we reveal that exogenous oxidative stress led to ferroptosis characterized by Fe2+ accumulation and lipid peroxidation in RPE cells. Glutathione specific gamma-glutamylcyclotransferase 1 (Chac1), as a component of the unfolded protein response (UPR) pathway, plays a pivotal role in oxidative-stress-induced cell ferroptosis via the regulation of glutathione depletion. These results indicate the biological significance of Chac1 as a novel contributor of oxidative-stress-induced ferroptosis in RPE, suggesting its potential role in AMD.
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11
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Pathologically high intraocular pressure disturbs normal iron homeostasis and leads to retinal ganglion cell ferroptosis in glaucoma. Cell Death Differ 2023; 30:69-81. [PMID: 35933500 PMCID: PMC9883496 DOI: 10.1038/s41418-022-01046-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 02/01/2023] Open
Abstract
Glaucoma can result in retinal ganglion cell (RGC) death and permanently damaged vision. Pathologically high intraocular pressure (ph-IOP) is the leading cause of damaged vision during glaucoma; however, controlling ph-IOP alone does not entirely prevent the loss of glaucomatous RGCs, and the underlying mechanism remains elusive. In this study, we reported an increase in ferric iron in patients with acute primary angle-closure glaucoma (the most typical glaucoma with ph-IOP damage) compared with the average population by analyzing free iron levels in peripheral serum. Thus, iron metabolism might be involved in regulating the injury of RGCs under ph-IOP. In vitro and in vivo studies confirmed that ph-IOP led to abnormal accumulation of ferrous iron in cells and retinas at 1-8 h post-injury and elevation of ferric iron in serum at 8 h post-injury. Nuclear receptor coactivator 4 (NCOA4)-mediated degradation of ferritin heavy polypeptide 1(FTH1) is essential to disrupt iron metabolism in the retina after ph-IOP injury. Furthermore, knockdown of Ncoa4 in vivo inhibited FTH1 degradation and reduced the retinal ferrous iron level. Elevated ferrous iron induced by ph-IOP led to a marked accumulation of pro-ferroptotic factors (lipid peroxidation and acyl CoA synthetase long-chain family member 4) and a depletion of anti-ferroptotic factors (glutathione, glutathione peroxidase 4, and nicotinamide adenine dinucleotide phosphate). These biochemical changes resulted in RGC ferroptosis. Deferiprone can pass through the blood-retinal barrier after oral administration and chelated abnormally elevated ferrous iron in the retina after ph-IOP injury, thus inhibiting RGC ferroptosis and protecting visual function. In conclusion, this study revealed the role of NCOA4-FTH1-mediated disturbance of iron metabolism and ferroptosis in RGCs during glaucoma. We demonstrate the protective effect of Deferiprone on RGCs via inhibition of ferroptosis, providing a research direction to understand and treat glaucoma via the iron homeostasis and ferroptosis pathways.
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12
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Ferroptosis inhibition by deferiprone, attenuates myelin damage and promotes neuroprotection in demyelinated optic nerve. Sci Rep 2022; 12:19630. [PMID: 36385152 PMCID: PMC9668997 DOI: 10.1038/s41598-022-24152-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 11/10/2022] [Indexed: 11/17/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease, which leads to focal demyelination in the brain and spinal cord. Studies showed that iron released during the course of myelin breakdown exacerbates tissue damage, which is in agreement with the features of iron-dependent cell death, ferroptosis. Here, we aimed to investigate the possible contribution of ferroptosis in the demyelinated optic nerve, and to explore the effectiveness of ferroptosis inhibitor, deferiprone (DFP), on the extent of demyelination, inflammation and axonal damage. For this purpose, focal demyelination was induced by injection of lysolecithin (LPC), into the optic nerve of male C57BL/6J mice. Afterward, optic nerves were harvested at different time points from as early as 6 h up to 7 days post-LPC injection. Next, to evaluate the effectiveness of DFP two groups of animals received daily intraperitoneal injection of DFP for 3 or 7 continuous days. Vehicle groups received saline. Iron deposition was observed at different time points post-LPC injection from 6 h to 7 days post injection. Examining ferroptosis markers showed a significant reduction in glutathione content along with increased level of malondialdehyde and upregulated ferroptosis marker genes at early time points after injection. Besides, DFP treatment during the inflammatory phase of the model resulted in decreased microgliosis and inflammation. Reduced demyelination, microgliosis and astrogliosis was shown in mice that received DFP for 7 days. Moreover, DFP protected against axonal damage and retinal ganglion cells loss. Our results suggest the possible contribution of ferroptosis pathway in the process of demyelination. The therapeutic strategies targeting iron deposition, e.g. DFP treatment might thus represent a promising therapeutic target for patients with MS.
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13
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Liu Y, Bell BA, Song Y, Zhang K, Anderson B, Axelsen PH, Bohannan W, Agbaga M, Park HG, James G, Brenna JT, Schmidt K, Dunaief JL, Shchepinov MS. Deuterated docosahexaenoic acid protects against oxidative stress and geographic atrophy-like retinal degeneration in a mouse model with iron overload. Aging Cell 2022; 21:e13579. [PMID: 35257475 PMCID: PMC9009113 DOI: 10.1111/acel.13579] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/24/2022] [Accepted: 02/11/2022] [Indexed: 01/03/2023] Open
Abstract
Oxidative stress plays a central role in age-related macular degeneration (AMD). Iron, a potent generator of hydroxyl radicals through the Fenton reaction, has been implicated in AMD. One easily oxidized molecule is docosahexaenoic acid (DHA), the most abundant polyunsaturated fatty acid in photoreceptor membranes. Oxidation of DHA produces toxic oxidation products including carboxyethylpyrrole (CEP) adducts, which are increased in the retinas of AMD patients. In this study, we hypothesized that deuterium substitution on the bis-allylic sites of DHA in photoreceptor membranes could prevent iron-induced retinal degeneration by inhibiting oxidative stress and lipid peroxidation. Mice were fed with either DHA deuterated at the oxidation-prone positions (D-DHA) or control natural DHA and then given an intravitreal injection of iron or control saline. Orally administered D-DHA caused a dose-dependent increase in D-DHA levels in the neural retina and retinal pigment epithelium (RPE) as measured by mass spectrometry. At 1 week after iron injection, D-DHA provided nearly complete protection against iron-induced retinal autofluorescence and retinal degeneration, as determined by in vivo imaging, electroretinography, and histology. Iron injection resulted in carboxyethylpyrrole conjugate immunoreactivity in photoreceptors and RPE in mice fed with natural DHA but not D-DHA. Quantitative PCR results were consistent with iron-induced oxidative stress, inflammation, and retinal cell death in mice fed with natural DHA but not D-DHA. Taken together, our findings suggest that DHA oxidation is central to the pathogenesis of iron-induced retinal degeneration. They also provide preclinical evidence that dosing with D-DHA could be a viable therapeutic strategy for retinal diseases involving oxidative stress.
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Affiliation(s)
- Yingrui Liu
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Brent A. Bell
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Ying Song
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Kevin Zhang
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Brandon Anderson
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Paul H. Axelsen
- Department of PharmacologyPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Whitney Bohannan
- Departments of Cell Biology and OphthalmologyUniversity of Oklahoma Health Sciences Center and the Dean McGee Eye InstituteOklahoma CityOklahomaUSA
| | - Martin‐Paul Agbaga
- Departments of Cell Biology and OphthalmologyUniversity of Oklahoma Health Sciences Center and the Dean McGee Eye InstituteOklahoma CityOklahomaUSA
| | - Hui Gyu Park
- Dell Pediatric Research InstituteUniversity of Texas at AustinAustinTexasUSA
| | - Genevieve James
- Dell Pediatric Research InstituteUniversity of Texas at AustinAustinTexasUSA
| | - J. Thomas Brenna
- Dell Pediatric Research InstituteUniversity of Texas at AustinAustinTexasUSA
| | | | - Joshua L. Dunaief
- F.M. Kirby Center for Molecular OphthalmologyScheie Eye InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
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14
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Shahandeh A, Bui BV, Finkelstein DI, Nguyen CTO. Effects of Excess Iron on the Retina: Insights From Clinical Cases and Animal Models of Iron Disorders. Front Neurosci 2022; 15:794809. [PMID: 35185447 PMCID: PMC8851357 DOI: 10.3389/fnins.2021.794809] [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: 10/14/2021] [Accepted: 12/17/2021] [Indexed: 01/19/2023] Open
Abstract
Iron plays an important role in a wide range of metabolic pathways that are important for neuronal health. Excessive levels of iron, however, can promote toxicity and cell death. An example of an iron overload disorder is hemochromatosis (HH) which is a genetic disorder of iron metabolism in which the body’s ability to regulate iron absorption is altered, resulting in iron build-up and injury in several organs. The retina was traditionally assumed to be protected from high levels of systemic iron overload by the blood-retina barrier. However, recent data shows that expression of genes that are associated with HH can disrupt retinal iron metabolism. Thus, the effects of iron overload on the retina have become an area of research interest, as excessively high levels of iron are implicated in several retinal disorders, most notably age–related macular degeneration. This review is an effort to highlight risk factors for excessive levels of systemic iron build-up in the retina and its potential impact on the eye health. Information is integrated across clinical and preclinical animal studies to provide insights into the effects of systemic iron loading on the retina.
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Affiliation(s)
- Ali Shahandeh
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Bang V. Bui
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC, Australia
| | - David I. Finkelstein
- Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Christine T. O. Nguyen
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC, Australia
- *Correspondence: Christine T. O. Nguyen,
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15
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Zeidan RS, Han SM, Leeuwenburgh C, Xiao R. Iron homeostasis and organismal aging. Ageing Res Rev 2021; 72:101510. [PMID: 34767974 DOI: 10.1016/j.arr.2021.101510] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/02/2021] [Accepted: 11/02/2021] [Indexed: 12/21/2022]
Abstract
Iron is indispensable for normal body functions across species because of its critical roles in red blood cell function and many essential proteins and enzymes required for numerous physiological processes. Regulation of iron homeostasis is an intricate process involving multiple modulators at the systemic, cellular, and molecular levels. Interestingly, emerging evidence has demonstrated that many modulators of iron homeostasis contribute to organismal aging and longevity. On the other hand, the age-related dysregulation of iron homeostasis is often associated with multiple age-related pathologies including bone resorption and neurodegenerative diseases such as Alzheimer's disease. Thus, a thorough understanding on the interconnections between systemic and cellular iron balance and organismal aging may help decipher the etiologies of multiple age-related diseases, which could ultimately lead to developing therapeutic strategies to delay aging and treat various age-related diseases. Here we present the current understanding on the mechanisms of iron homeostasis. We also discuss the impacts of aging on iron homeostatic processes and how dysregulated iron metabolism may affect aging and organismal longevity.
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16
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Liu Y, Bell BA, Song Y, Kim HJ, Sterling JK, Kim BJ, Poli M, Guo M, Zhang K, Rao A, Sparrow JR, Su G, Dunaief JL. Intraocular iron injection induces oxidative stress followed by elements of geographic atrophy and sympathetic ophthalmia. Aging Cell 2021; 20:e13490. [PMID: 34626070 PMCID: PMC8590099 DOI: 10.1111/acel.13490] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/24/2021] [Accepted: 09/14/2021] [Indexed: 01/24/2023] Open
Abstract
Iron has been implicated in the pathogenesis of age‐related retinal diseases, including age‐related macular degeneration (AMD). Previous work showed that intravitreal (IVT) injection of iron induces acute photoreceptor death, lipid peroxidation, and autofluorescence (AF). Herein, we extend this work, finding surprising chronic features of the model: geographic atrophy and sympathetic ophthalmia. We provide new mechanistic insights derived from focal AF in the photoreceptors, quantification of bisretinoids, and localization of carboxyethyl pyrrole, an oxidized adduct of docosahexaenoic acid associated with AMD. In mice given IVT ferric ammonium citrate (FAC), RPE died in patches that slowly expanded at their borders, like human geographic atrophy. There was green AF in the photoreceptor ellipsoid, a mitochondria‐rich region, 4 h after injection, followed later by gold AF in rod outer segments, RPE and subretinal myeloid cells. The green AF signature is consistent with flavin adenine dinucleotide, while measured increases in the bisretinoid all‐trans‐retinal dimer are consistent with the gold AF. FAC induced formation carboxyethyl pyrrole accumulation first in photoreceptors, then in RPE and myeloid cells. Quantitative PCR on neural retina and RPE indicated antioxidant upregulation and inflammation. Unexpectedly, reminiscent of sympathetic ophthalmia, autofluorescent myeloid cells containing abundant iron infiltrated the saline‐injected fellow eyes only if the contralateral eye had received IVT FAC. These findings provide mechanistic insights into the potential toxicity caused by AMD‐associated retinal iron accumulation. The mouse model will be useful for testing antioxidants, iron chelators, ferroptosis inhibitors, anti‐inflammatory medications, and choroidal neovascularization inhibitors.
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Affiliation(s)
- Yingrui Liu
- Department of Ophthalmology The Second Hospital of Jilin University Changchun China
- F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
| | - Brent A. Bell
- F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
| | - Ying Song
- F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
| | - Hye J. Kim
- Department of Ophthalmology Harkness Eye Institute Columbia University Medical Center New York New York USA
| | - Jacob K. Sterling
- F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
| | - Benjamin J. Kim
- Department of Ophthalmology Scheie Eye Institute University of Pennsylvania Philadelphia Pennsylvania USA
| | - Maura Poli
- Department of Molecular and Translational Medicine University of Brescia Brescia Italy
| | - Michelle Guo
- F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
| | - Kevin Zhang
- F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
| | - Aditya Rao
- Department of Molecular Life Science University of Pennsylvania Philadelphia Pennsylvania USA
| | - Janet R. Sparrow
- Department of Ophthalmology Harkness Eye Institute Columbia University Medical Center New York New York USA
| | - Guanfang Su
- Department of Ophthalmology The Second Hospital of Jilin University Changchun China
| | - Joshua L. Dunaief
- F.M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania USA
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17
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Kim HJ, Montenegro D, Zhao J, Sparrow JR. Bisretinoids of the Retina: Photo-Oxidation, Iron-Catalyzed Oxidation, and Disease Consequences. Antioxidants (Basel) 2021; 10:antiox10091382. [PMID: 34573014 PMCID: PMC8467448 DOI: 10.3390/antiox10091382] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 01/06/2023] Open
Abstract
The retina and, in particular, retinal pigment epithelial cells are unusual for being encumbered by exposure to visible light, while being oxygen-rich, and also amassing photoreactive molecules. These fluorophores (bisretinoids) are generated as a byproduct of the activity of vitamin A aldehyde-the chromophore necessary for vision. Bisretinoids form in photoreceptor cells due to random reactions of two molecules of vitamin A aldehyde with phosphatidylethanolamine; bisretinoids are subsequently transferred to retinal pigment epithelial (RPE) cells, where they accumulate in the lysosomal compartment with age. Bisretinoids can generate reactive oxygen species by both energy and electron transfer, and they become photo-oxidized and photolyzed in the process. While these fluorescent molecules are accrued by RPE cells of all healthy eyes, they are also implicated in retinal disease.
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Affiliation(s)
- Hye Jin Kim
- Department of Ophthalmology, Columbia University Medical Center, 635 W., 165th Str., New York, NY 10032, USA; (H.J.K.); (D.M.); (J.Z.)
| | - Diego Montenegro
- Department of Ophthalmology, Columbia University Medical Center, 635 W., 165th Str., New York, NY 10032, USA; (H.J.K.); (D.M.); (J.Z.)
| | - Jin Zhao
- Department of Ophthalmology, Columbia University Medical Center, 635 W., 165th Str., New York, NY 10032, USA; (H.J.K.); (D.M.); (J.Z.)
| | - Janet R. Sparrow
- Department of Ophthalmology, Columbia University Medical Center, 635 W., 165th Str., New York, NY 10032, USA; (H.J.K.); (D.M.); (J.Z.)
- Department of Pathology and Cell Biology, Columbia University Medical Center, 635 W., 165th Str., New York, NY 10032, USA
- Correspondence: ; Tel.: +1-212-305-9944
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18
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Belmouhand M, Eckmann-Hansen C, Ilginis T, Leinøe EB, Mortensen BK, Larsen M. Iron overload and iron chelating agent exposure in anemia-associated outer retinal degeneration: a case report and review of the literature. BMC Ophthalmol 2021; 21:277. [PMID: 34256738 PMCID: PMC8278719 DOI: 10.1186/s12886-021-02030-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/29/2021] [Indexed: 11/20/2022] Open
Abstract
Background Deferoxamine retinopathy is the informally designated term used to describe a characteristic pattern of outer retinal degeneration in iron-overloaded chronic anemia patients who are treated with deferoxamine. We hypothesize that insufficiently treated iron overloading and not only deferoxamine is the cause of the retinal degeneration. Our case report is based on exposure histories of two anemia patients and literature review. Case presentation Both anemia patients presented with bilateral visual loss secondary to photoreceptor and retinal pigment epithelium degeneration. Chart review showed that visual loss came after a year-long slow, and rather monotonous rise in plasma ferritin concentrations, with no obvious relation to iron chelator exposure. In one patient, the onset of symptomatic visual loss came after a bout of fever followed by two additional febrile episodes, all accompanied by plasma ferritin spikes. Adjustment of iron chelation therapy did not improve visual function. Experimental studies clearly show that both systemic and intraocular exposure to iron ions can induce retinal degeneration. Conclusion The available evidence indicates that retinal degeneration in chronic anemia patients treated by deferoxamine is cause by insufficient iron chelation, not by deferoxamine. The actual role of iron chelating agents may be to promote a long enough survival to allow the slow development of retinal siderosis.
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Affiliation(s)
- Mohamed Belmouhand
- Department of Ophthalmology, Rigshospitalet, Copenhagen University Hospital, Glostrup, Denmark. .,Department of Clinical Medicine, Faculty of Healthy and Medical Science, University of Copenhagen, Copenhagen, Denmark.
| | - Christina Eckmann-Hansen
- Department of Ophthalmology, Rigshospitalet, Copenhagen University Hospital, Glostrup, Denmark.,Department of Clinical Medicine, Faculty of Healthy and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Tomas Ilginis
- Department of Ophthalmology, Rigshospitalet, Copenhagen University Hospital, Glostrup, Denmark
| | - Eva Birgitte Leinøe
- Department of Hematology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Bo Kok Mortensen
- Department of Hematology, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
| | - Michael Larsen
- Department of Ophthalmology, Rigshospitalet, Copenhagen University Hospital, Glostrup, Denmark.,Department of Clinical Medicine, Faculty of Healthy and Medical Science, University of Copenhagen, Copenhagen, Denmark
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Song Q, Zhang F, Han X, Yang Y, Zhao Y, Duan J. Ameliorative effects and mechanisms of salvianic acid A on retinal iron overload in vivo and in vitro. Exp Eye Res 2021; 209:108642. [PMID: 34058232 DOI: 10.1016/j.exer.2021.108642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/17/2021] [Accepted: 05/24/2021] [Indexed: 12/12/2022]
Abstract
Excessive iron can be accumulated in the retina and lead to retinal iron overload. Salvianic acid A (SAA) has a variety of pharmacologic effects, but there is only a limited understanding of its benefits for retinal iron overload. The aim of this study was to examine the protective effects and latent mechanisms of SAA on retinal iron overload. SAA reduced iron in the serum and retina, attenuated pathophysiological changes, and reduced retinal iron deposition in the retinas of iron-overloaded mice. It also reduced intracellular iron in ARPE-19 cells by regulating iron-handling proteins and chelating with iron. It also significantly inhibited cellular oxidative and inflammatory damage by increasing the nuclear translocation of nuclear erythroid 2-related factor 2 (Nrf2) while decreasing nuclear factor-kappa B (NF-κB), protecting the ARPE-19 cells from apoptosis by suppressing the Bax/Bcl-2 ratio, cytochrome c release, caspase activation, and poly ADP-ribose polymerase cleavage. The ability of SAA to inhibit apoptosis, increase nuclear Nrf2 expression, and decrease nuclear NF-κB expression was further confirmed in the retinas of iron-overloaded mice. This study demonstrates that SAA shows significant protective effects against retinal iron overload; its mechanisms might be associated with iron chelation; regulation of iron-handling proteins; and inhibition of oxidative stress, inflammation and apoptosis.
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Affiliation(s)
- Qiongtao Song
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu, 610084, Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China
| | - Fuwen Zhang
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu, 610084, Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China
| | - Xue Han
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, No.326 Xinshi South Road, Shijiazhuang, 050200, Hebei, China
| | - Yanrong Yang
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu, 610084, Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China
| | - Ying Zhao
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu, 610084, Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China
| | - Junguo Duan
- Eye School of Chengdu University of TCM, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China; Ineye Hospital of Chengdu University of TCM, No.8 Xinghui Road, Chengdu, 610084, Sichuan, China; Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, No.37 Twelve Bridge Road, Chengdu, 610075, Sichuan, China.
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20
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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: 75] [Impact Index Per Article: 25.0] [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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21
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Zhao J, Kim HJ, Ueda K, Zhang K, Montenegro D, Dunaief JL, Sparrow JR. A vicious cycle of bisretinoid formation and oxidation relevant to recessive Stargardt disease. J Biol Chem 2021; 296:100259. [PMID: 33837742 PMCID: PMC7948646 DOI: 10.1016/j.jbc.2021.100259] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/09/2020] [Accepted: 01/05/2021] [Indexed: 11/29/2022] Open
Abstract
The ability of iron to transfer electrons enables the contribution of this metal to a variety of cellular activities even as the redox properties of iron are also responsible for the generation of hydroxyl radicals (•OH), the most destructive of the reactive oxygen species. We previously showed that iron can promote the oxidation of bisretinoid by generating highly reactive hydroxyl radical (•OH). Now we report that preservation of iron regulation in the retina is not sufficient to prevent iron-induced bisretinoid oxidative degradation when blood iron levels are elevated in liver-specific hepcidin knockout mice. We obtained evidence for the perpetuation of Fenton reactions in the presence of the bisretinoid A2E and visible light. On the other hand, iron chelation by deferiprone was not associated with changes in postbleaching recovery of 11-cis-retinal or dark-adapted ERG b-wave amplitudes indicating that the activity of Rpe65, a rate-determining visual cycle protein that carries an iron-binding domain, is not affected. Notably, iron levels were elevated in the neural retina and retinal pigment epithelial (RPE) cells of Abca4−/− mice. Consistent with higher iron content, ferritin-L immunostaining was elevated in RPE of a patient diagnosed with ABCA4-associated disease and in RPE and photoreceptor cells of Abca4−/− mice. In neural retina of the mutant mice, reduced Tfrc mRNA was also an indicator of retinal iron overload. Thus iron chelation may defend retina when bisretinoid toxicity is implicated in disease processes.
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Affiliation(s)
- Jin Zhao
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, USA
| | - Hye Jin Kim
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, USA
| | - Keiko Ueda
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, USA
| | - Kevin Zhang
- Department of Ophthalmology, University of Pennsylvania, Philadelphia Pennsylvania, USA
| | - Diego Montenegro
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, USA
| | - Joshua L Dunaief
- Department of Ophthalmology, University of Pennsylvania, Philadelphia Pennsylvania, USA
| | - Janet R Sparrow
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, USA; Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, USA.
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22
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Astragaloside IV protects against retinal iron overload toxicity through iron regulation and the inhibition of MAPKs and NF-κB activation. Toxicol Appl Pharmacol 2020; 410:115361. [PMID: 33285147 DOI: 10.1016/j.taap.2020.115361] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 12/27/2022]
Abstract
Iron overload toxicity has been implicated in retinal pigment epithelial cell injury in age-related macular degeneration. This study investigates the effects of astragaloside IV (AS-IV), a potential retinal protective agent, on the toxicity process of retinal iron overload in vivo and in vitro. AS-IV partially restored the retinal expression of rhodopsin and retinal pigment epithelium-specific 65 kDa protein, suppressed oxidative stress and inflammatory markers, and alleviated iron deposition and retinal pathological changes in vivo. Also, AS-IV inhibited the phosphorylation of p38 and ERK mitogen-activated protein kinases (MAPKs), as well as the nuclear translocation of nuclear factor-kappa B (NF-κB). Furthermore, AS-IV prevented cell death by decreasing the ratio of Bax/Bcl-2, caspase-3, and cleaved caspase-3 expression in vitro. Although there are no chelation effects between AS-IV and iron, AS-IV can reduce intracellular iron by regulating iron-handling proteins in ARPE-19 cells (Cav1.2, divalent metal transporter-1, transferrin receptor 1, and heavy-chain ferritin). In conclusion, the results show that AS-IV has significant protective effects against retinal iron overload toxicity and suggest that iron regulation and the inhibition of MAPKs and NF-κB activation might be mechanisms underlying the effects of AS-IV.
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23
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Micera A, Bruno L, Cacciamani A, Rongioletti M, Squitti R. Alzheimer's Disease and Retinal Degeneration: A Glimpse at Essential Trace Metals in Ocular Fluids and Tissues. Curr Alzheimer Res 2020; 16:1073-1083. [PMID: 31642780 DOI: 10.2174/1567205016666191023114015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 09/28/2019] [Accepted: 10/21/2019] [Indexed: 01/19/2023]
Abstract
BACKGROUND Life expectancy is increasing all over the world, although neurodegenerative disorders might drastically affect the individual activity of aged people. Of those, Alzheimer's Disease (AD) is one of the most social-cost age-linked diseases of industrialized countries. To date, retinal diseases seem to be more common in the developing world and characterize principally aged people. Agerelated Macular Degeneration (AMD) is a late-onset, neurodegenerative retinal disease that shares several clinical and pathological features with AD, including stress stimuli such as oxidative stress, inflammation and amyloid formations. METHODS In both diseases, the detrimental intra/extra-cellular deposits have many similarities. Aging, hypercholesterolemia, hypertension, obesity, arteriosclerosis and smoking are risk factors to develop both diseases. Cellular aging routes have similar organelle and signaling patterns in retina and brain. The possibility to find out new research strategies represent a step forward to disclose potential treatment for both of them. Essential trace metals play critical roles in both physiological and pathological condition of retina, optic nerve and brain, by influencing metabolic processes chiefly upon complex multifactorial pathogenesis. CONCLUSION Hence, this review addresses current knowledge about some up-to-date investigated essential trace metals associated with AD and AMD. Changes in the levels of systemic and ocular fluid essential metals might reflect the early stages of AMD, possibly disclosing neurodegeneration pathways shared with AD, which might open to potential early detection.
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Affiliation(s)
- Alessandra Micera
- Research Laboratories in Ophthalmology, IRCCS - Fondazione Bietti, Rome, Italy
| | - Luca Bruno
- Research Laboratories in Ophthalmology, IRCCS - Fondazione Bietti, Rome, Italy
| | - Andrea Cacciamani
- Research Laboratories in Ophthalmology, IRCCS - Fondazione Bietti, Rome, Italy
| | - Mauro Rongioletti
- Department of Laboratory Medicine, Research and Development Division, San Giovanni Calibita, Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy
| | - Rosanna Squitti
- IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, BS, Italy
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24
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Singh N, Chaudhary S, Ashok A, Lindner E. Prions and prion diseases: Insights from the eye. Exp Eye Res 2020; 199:108200. [PMID: 32858007 DOI: 10.1016/j.exer.2020.108200] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/24/2020] [Accepted: 08/21/2020] [Indexed: 12/30/2022]
Abstract
Prion diseases are invariably fatal neurodegenerative disorders that have gained much publicity due to their transmissible nature. Sporadic Creutzfeldt-Jakob disease (sCJD) is the most common human prion disorder, with an incidence of 1 in a million. Inherited prion disorders are relatively rare, and associated with mutations in the prion protein gene. More than 50 different point mutations, deletions, and insertions have been identified so far. Most are autosomal dominant and fully penetrant. Prion disorders also occur in animals, and are of major concern because of the potential for spreading to humans. The principal pathogenic event underlying all prion disorders is a change in the conformation of prion protein (PrPC) from a mainly α-helical to a β-sheet rich isoform, PrP-scrapie (PrPSc). Accumulation of PrPSc in the brain parenchyma is the major cause of neuronal degeneration. The mechanism by which PrPSc is transmitted, propagates, and causes neurodegenerative changes has been investigated over the years, and several clues have emerged. Efforts are also ongoing for identifying specific and sensitive diagnostic tests for sCJD and animal prion disorders, but success has been limited. The eye is suitable for these evaluations because it shares several anatomical and physiological features with the brain, and can be observed in vivo during disease progression. The retina, considered an extension of the central nervous system, is involved extensively in prion disorders. Accordingly, Optical Coherence Tomography and electroretinogram have shown some promise as pre-mortem diagnostic tests for human and animal prion disorders. However, a complete understanding of the physiology of PrPC and pathobiology of PrPSc in the eye is essential for developing specific and sensitive tests. Below, we summarize recent progress in ocular physiology and pathology in prion disorders, and the eye as an anatomically accessible site to diagnose, monitor disease progression, and test therapeutic options.
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Affiliation(s)
- Neena Singh
- Departments of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
| | - Suman Chaudhary
- Departments of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Ajay Ashok
- Departments of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Ewald Lindner
- Department of Ophthalmology, Medical University of Graz, Auenbruggerplatz 4, 8036, Graz, Austria
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25
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Shahandeh A, Bui BV, Finkelstein DI, Nguyen CTO. Therapeutic applications of chelating drugs in iron metabolic disorders of the brain and retina. J Neurosci Res 2020; 98:1889-1904. [DOI: 10.1002/jnr.24685] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 01/19/2023]
Affiliation(s)
- Ali Shahandeh
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences University of Melbourne Parkville VIC Australia
| | - Bang V. Bui
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences University of Melbourne Parkville VIC Australia
| | | | - Christine T. O. Nguyen
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences University of Melbourne Parkville VIC Australia
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26
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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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27
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Oral administration of the iron chelator deferiprone protects against loss of retinal ganglion cells in a mouse model of glaucoma. Exp Eye Res 2020; 193:107961. [PMID: 32045598 DOI: 10.1016/j.exer.2020.107961] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 01/10/2020] [Accepted: 02/05/2020] [Indexed: 12/22/2022]
Abstract
Glaucoma is a progressive neurodegenerative process affecting the retinal ganglion cells (RGCs) and the optic nerve. Oxidative stress has been implicated in glaucoma pathogenesis, and iron is a potent generator of oxidative stress. The oral iron chelator deferiprone (DFP) is protective against retinal degenerations associated with oxidative stress. To test whether DFP could be protective in glaucoma, we used microbead injections to induce elevated intraocular pressure (IOP) in a cohort of 3-month old C57BL/6J mice. One eye of each animal was injected with magnetic microbeads resulting in ocular hypertension for >7 weeks while the fellow eye was injected with saline and served as a normotensive internal control. While half of the cohort received oral DFP (1 mg/ml in the drinking water), the other half did not and served as controls. After 8 weeks, Brn3a immunolabeling of flat-mounted retinas was used for manual RGC quantification. Axon counts were obtained from thin sections of optic nerves using the AxonJ plugin for ImageJ. DFP administration was protective against RGC and optic nerve loss in the setting of elevated IOP. These results suggest that iron chelation by DFP may provide glaucoma neuroprotection.
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28
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Ashok A, Chaudhary S, McDonald D, Kritikos A, Bhargava D, Singh N. Local synthesis of hepcidin in the anterior segment of the eye: A novel observation with physiological and pathological implications. Exp Eye Res 2020; 190:107890. [PMID: 31811823 PMCID: PMC6931014 DOI: 10.1016/j.exer.2019.107890] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 10/27/2019] [Accepted: 12/01/2019] [Indexed: 12/22/2022]
Abstract
PURPOSE The avascular cornea, trabecular meshwork (TM), and lens obtain iron, an essential biometal, from the aqueous humor (AH). The mechanism by which this exchange is regulated, however, is unclear. Recently we reported that non-pigmented ciliary epithelial cells express ferroportin (Fpn) (Ashok, 2018b), an iron export protein modulated by hepcidin, the master regulator of iron homeostasis secreted mainly by the liver. Here, we explored whether ciliary epithelial and other cells in the anterior segment synthesize hepcidin, suggesting local regulation of iron exchange at this site. METHODS Human and bovine eyes were dissected to isolate the ciliary body (CB), corneal endothelial (CE), TM, lens epithelial (LE), and outer epithelial cell layer of the iris. Total mRNA and protein lysates were processed to evaluate the synthesis and expression of hepcidin, the iron regulatory peptide hormone, Fpn, the only known iron export protein, ceruloplasmin (Cp), a ferroxidase necessary for iron export, transferrin receptor (TfR), a major iron uptake protein, and ferritin, a major iron storage protein. A combination of techniques including reverse transcription polymerase chain reaction (RT-PCR) of total mRNA, Western blotting of protein lysates, and immunofluorescence of fixed tissue sections were used to accomplish these goals. RESULTS RT-PCR of isolated tissue samples revealed hepcidin-specific mRNA in the CB, TM, CE, and LE of the bovine eye. Western blotting of protein lysates from these tissues showed reactivity for hepcidin, Fpn, ferritin, and TfR. Western blotting and immunohistochemistry of similar tissues isolated from cadaveric human eyes showed expression of hepcidin, Fpn, and Cp in these samples. Notably, Fpn and Cp were expressed on the basolateral membrane of non-pigmented ciliary epithelial cells, facing the AH. CONCLUSIONS Synthesis and expression of hepcidin and Fpn in the ciliary epithelium suggests local regulation of iron transport from choroidal plexus in the ciliary body to the AH across the blood-aqueous barrier. Expression of hepcidin and Fpn in CE, TM, and LE cells indicates additional regulation of iron exchange between the AH and cornea, TM, and lens, suggesting autonomous regulation of iron homeostasis in the anterior segment. Physiological and pathological implications of these observations are discussed.
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Affiliation(s)
- Ajay Ashok
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Suman Chaudhary
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Dallas McDonald
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Alexander Kritikos
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Disha Bhargava
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Neena Singh
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
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29
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Song Q, Zhao Y, Li Q, Han X, Duan J. Puerarin protects against iron overload-induced retinal injury through regulation of iron-handling proteins. Biomed Pharmacother 2019; 122:109690. [PMID: 31786468 DOI: 10.1016/j.biopha.2019.109690] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/11/2019] [Accepted: 11/20/2019] [Indexed: 12/14/2022] Open
Abstract
Excess iron content can build up in the retina and lead to iron-mediated retinal injury. An important isoflavone C-glucoside, puerarin, has been reported to be involved in retinal protection. In this experiment, we studied the effects and potential mechanisms of puerarin on retinal injury in vivo and in vitro. We found that puerarin reduced serum and retinal iron content, attenuated the pathophysiological changes and retinal iron deposition, and partially prevented the decrease of rhodopsin and retinal pigment epithelium-specific 65 kDa protein expression in retinas of iron-overload mice. Puerarin rescued the abnormal expression of iron-handling proteins in the mouse retina and suppressed the oxidative stress induced by iron overload, as evident from the enhanced activity of superoxide dismutase, catalase, and glutathione peroxidase and decreased content of malondialdehyde. Moreover, puerarin inhibited the phosphorylation of p38 and ERK mitogen-activated protein kinases (MAPKs) and signal transducer and activator of transcription 3 (STAT3), thereby protecting the retinal cells from apoptosis by suppressing cytochrome c release, caspase activation, and poly (ADP-ribose) polymerase cleavage in vivo. Also, the ability of puerarin to regulate iron-handling proteins, decrease intracellular Fe2+, and inhibit cell apoptosis was further confirmed in ARPE-19 cells. The experimental data verify the protective role of puerarin in the treatment of retinal injury caused by iron overload; its possible mechanisms might be associated with regulation of iron-handling proteins, enhancement of the antioxidant capacity, and the inhibition of MAPK and STAT3 activation and the apoptotic pathways under iron overload conditions.
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Affiliation(s)
- Qiongtao Song
- Department of Ophthalmology, Chengdu University of Traditional Chinese Medicine, No.37 Twelve Bridge Road, Chengdu 610075, Sichuan, China
| | - Ying Zhao
- Department of Ophthalmology, Chengdu University of Traditional Chinese Medicine, No.37 Twelve Bridge Road, Chengdu 610075, Sichuan, China
| | - Qiang Li
- Department of Ophthalmology, Chengdu University of Traditional Chinese Medicine, No.37 Twelve Bridge Road, Chengdu 610075, Sichuan, China
| | - Xue Han
- Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Shijiazhuang 050200, Hebei, China
| | - Junguo Duan
- Department of Ophthalmology, Chengdu University of Traditional Chinese Medicine, No.37 Twelve Bridge Road, Chengdu 610075, Sichuan, China.
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30
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Heydarian S, Jafari R, Dailami KN, Hashemi H, Jafarzadehpour E, Heirani M, Yekta A, Mahjoob M, Khabazkhoob M. Ocular abnormalities in beta thalassemia patients: prevalence, impact, and management strategies. Int Ophthalmol 2019; 40:511-527. [PMID: 31602527 DOI: 10.1007/s10792-019-01189-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/25/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND Beta thalassemia (β-thalassemia) is a hereditary disease caused by defective globin synthesis and can be classified into three categories of minor (β-TMi), intermedia (β-TI), and major (β-TM) thalassemia. The aim of our study is to investigate the effects of β-thalassemia and its treatment methods on different parts of the eye and how early-diagnostic methods of ocular complications in this disorder would prevent further ocular complications in these patients by immediate treatment and diet change. METHODS We developed a search strategy using a combination of the words Beta thalassemia, Ocular abnormalities, Iron overload, chelation therapy to identify all articles from PubMed, Web of Science, Scopus, and Google Scholar up to December 2018. To find more articles and to ensure that databases were thoroughly searched, the reference lists of selected articles were also reviewed. RESULTS Complications such as retinopathy, crystalline lens opacification, color vision deficiency, nyctalopia, depressed visual field, reduced visual acuity, reduced contrast sensitivity, amplitude reduction in a-wave and b-wave in Electroretinography (ERG), and decrease in the Arden ratio in Electrooculography (EOG) have all been reported in β-thalassemia patients undergoing chelation therapy. CONCLUSION Ocular problems due to β-thalassemia may be a result of anemia, iron overload in the body tissue, side effects of iron chelators, and the complications of orbital bone marrow expansion.
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Affiliation(s)
- Samira Heydarian
- Department of Rehabilitation Sciences, School of Allied Medical Sciences, Mazandaran University of Medical Sciences, Sari, Iran
| | - Reza Jafari
- Department of Ophthalmology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | | | - Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Ebrahim Jafarzadehpour
- Department of Optometry, Rehabilitation Faculty, Iran University of Medical Sciences, Tehran, Iran
| | - Mohsen Heirani
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Abbasali Yekta
- Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Monireh Mahjoob
- Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Mehdi Khabazkhoob
- Department of Psychiatric Nursing and Management, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Comparative localization of cystathionine beta synthases and cystathionine gamma lyase in canine, non-human primate and human retina. Exp Eye Res 2019; 181:72-84. [PMID: 30653965 DOI: 10.1016/j.exer.2019.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 12/15/2022]
Abstract
Chronic exposure of the retina to light and high concentrations of polyunsaturated fatty acid in photoreceptor cells make this tissue susceptible to oxidative damage. As retinal degenerative diseases are associated with photoreceptor degeneration, the antioxidant activity of both hydrogen sulfide (H2S) and glutathione (GSH) may play an important role in ameliorating disease progression. H2S production is driven by cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS), the key enzymes that also drive transsulfuration pathway (TSP) necessary for GSH production. As it is currently unclear whether localized production of either H2S or GSH contributes to retinal homeostasis, we undertook a comparative analysis of CBS and CSE expression in canine, non-human primate (NHP) and human retinas to determine if these antioxidants could play a regulatory role in age-related or disease-associated retinal degeneration. Retinas from normal dogs, NHPs and humans were used for the study. Laser capture microdissection (LCM) was performed to isolate individual layers of the canine retina and analyze CBS and CSE gene expression by qRT-PCR. Immunohistochemistry and western blotting were performed for CBS and CSE labeling and protein expression in dog, NHP, and human retina, respectively. Using qRT-PCR, western blot, and immunohistochemistry (IHC), we showed that CBS and CSE are expressed in the canine, NHP, and human retina. IHC results from canine retina demonstrated increased expression levels of CBS but not CSE with post-developmental aging. IHC results also showed non-overlapping localization of both proteins with CBS presenting in rods, amacrine, horizontal, and nerve fiber cell layers while CSE was expressed by RPE, cones and Mϋller cells. Finally, we demonstrated that these enzymes localized to all three layers of canine, NHP and human retina: photoreceptors, outer plexiform layer (OPL) and notably in the ganglion cells layer/nerve fiber layer (GCL/NFL). QRT-PCR performed using RNA extracted from tissues isolated from these cell layers using laser capture microdissection (LCM) confirmed that each of CBS and CSE are expressed equally in these three layers. Together, these findings reveal that CSE and CBS are expressed in the retina, thereby supporting further studies to determine the role of H2S and these proteins in oxidative stress and apoptosis in retinal degenerative diseases.
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Shu W, Dunaief JL. Potential Treatment of Retinal Diseases with Iron Chelators. Pharmaceuticals (Basel) 2018; 11:ph11040112. [PMID: 30360383 PMCID: PMC6316536 DOI: 10.3390/ph11040112] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/08/2018] [Accepted: 10/10/2018] [Indexed: 12/30/2022] Open
Abstract
Iron is essential for life, while excess iron can be toxic. Iron generates hydroxyl radical, which is the most reactive free radical, causing oxidative stress. Since iron is absorbed through the diet but not excreted from the body, it accumulates with age in tissues, including the retina, consequently leading to age-related toxicity. This accumulation is further promoted by inflammation. Hereditary diseases such as aceruloplasminemia, Friedreich’s ataxia, pantothenate kinase-associated neurodegeneration, and posterior column ataxia with retinitis pigmentosa involve retinal degeneration associated with iron dysregulation. In addition to hereditary causes, dietary or parenteral iron supplementation has been recently reported to elevate iron levels in the retinal pigment epithelium (RPE) and promote retinal degeneration. Ocular siderosis from intraocular foreign bodies or subretinal hemorrhage can also lead to retinopathy. Evidence from mice and humans suggests that iron toxicity may contribute to age-related macular degeneration pathogenesis. Iron chelators can protect photoreceptors and RPE in various mouse models. The therapeutic potential for iron chelators is under investigation.
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Affiliation(s)
- Wanting Shu
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, 305 Stellar-Chance Laboratory, Philadelphia, PA 19104, USA.
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China.
| | - Joshua L Dunaief
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, 305 Stellar-Chance Laboratory, Philadelphia, PA 19104, USA.
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Georgakopoulos CD, Tsapardoni F, Kostopoulou EV, Makri OE. Pattern dystrophies in patients treated with deferoxamine: report of two cases and review of the literature. BMC Ophthalmol 2018; 18:246. [PMID: 30208862 PMCID: PMC6134579 DOI: 10.1186/s12886-018-0911-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/31/2018] [Indexed: 11/25/2022] Open
Abstract
Background Deferoxamine (DFO) is one of the most commonly used chelation treatments for transfusional hemosiderosis. Pattern dystrophies constitute a distinct entity of retinal disorders that has been occasionally identified in association with deferoxamine. Case presentation We report two cases of bilateral macular pattern dystrophy in transfusion dependent patients undergoing chronic chelation therapy with deferoxamine due to thalassemias. Our patients were evaluated with multimodal imaging and the results are presented. Both patients had normal cone and rod responses in the full-field electroretinogram and continued the prescribed chelation therapy, after hematology consult. The patients were followed up every 3 months for 2 and 4 years respectively for possible deterioration. Their best corrected visual acuity remained stable with no anatomic change on Optical Coherence Tomography findings. Conclusion Multimodal imaging of our patients allowed a better evaluation and possibly earlier detection of the DFO-related changes. Screening and close follow up of patients under chronic chelating therapy is important in order to promptly diagnose and manage possible toxicity either with discontinuation of the offending agent or dose modification.
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Affiliation(s)
| | - Foteini Tsapardoni
- Department of Ophthalmology, Medical School, University of Patras, 265 04, Patras, Greece
| | - Elli V Kostopoulou
- Department of Ophthalmology, Medical School, University of Patras, 265 04, Patras, Greece
| | - Olga E Makri
- Department of Ophthalmology, Medical School, University of Patras, 265 04, Patras, Greece.
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Léger H, Santana E, Leu NA, Smith ET, Beltran WA, Aguirre GD, Luca FC. Ndr kinases regulate retinal interneuron proliferation and homeostasis. Sci Rep 2018; 8:12544. [PMID: 30135513 PMCID: PMC6105603 DOI: 10.1038/s41598-018-30492-9] [Citation(s) in RCA: 6] [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: 02/25/2018] [Accepted: 08/01/2018] [Indexed: 12/31/2022] Open
Abstract
Ndr2/Stk38l encodes a protein kinase associated with the Hippo tumor suppressor pathway and is mutated in a naturally-occurring canine early retinal degeneration (erd). To elucidate the retinal functions of Ndr2 and its paralog Ndr1/Stk38, we generated Ndr1 and Ndr2 single knockout mice. Although retinal lamination appeared normal in these mice, Ndr deletion caused a subset of Pax6-positive amacrine cells to proliferate in differentiated retinas, while concurrently decreasing the number of GABAergic, HuD and Pax6-positive amacrine cells. Retinal transcriptome analyses revealed that Ndr2 deletion increased expression of neuronal stress genes and decreased expression of synaptic organization genes. Consistent with the latter, Ndr deletion dramatically reduced levels of Aak1, an Ndr substrate that regulates vesicle trafficking. Our findings indicate that Ndr kinases are important regulators of amacrine and photoreceptor cells and suggest that Ndr kinases inhibit the proliferation of a subset of terminally differentiated cells and modulate interneuron synapse function via Aak1.
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Affiliation(s)
- Hélène Léger
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - Evelyn Santana
- Division of Experimental Retinal Therapies, Department of Clinical Sciences and Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - N Adrian Leu
- Center for Animal Transgenesis and Germ Cell Research, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - Eliot T Smith
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - William A Beltran
- Division of Experimental Retinal Therapies, Department of Clinical Sciences and Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - Gustavo D Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences and Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States
| | - Francis C Luca
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, United States.
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Abstract
Cells are subject to metabolic sources of oxidizing species and to the need to regulate Fe, a redox-active metal. Retinal pigment epithelial (RPE) cells have to contend with an additional, unique source of oxidative stress: photooxidative insult from bisretinoids that accumulate as lipofuscin. Here we report that Fe can interact with bisretinoids in RPE to promote cell damage. These findings inform disease processes in both Fe-related and bisretinoid-associated retinal degeneration. The link between Fe and bisretinoid oxidation also highlights opportunities for repurposed and combination therapies. This could include visual cycle inhibitors as a treatment for maculopathy associated with elevated retinal Fe, and Fe chelation to aid in suppressing the damaging effects of bisretinoids in juvenile and age-related macular degeneration. Intracellular Fe plays a key role in redox active energy and electron transfer. We sought to understand how Fe levels impact the retina, given that retinal pigment epithelial (RPE) cells are also challenged by accumulations of vitamin A aldehyde adducts (bisretinoid lipofuscin) that photogenerate reactive oxygen species and photodecompose into damaging aldehyde- and dicarbonyl-bearing species. In mice treated with the Fe chelator deferiprone (DFP), intracellular Fe levels, as reflected in transferrin receptor mRNA expression, were reduced. DFP-treated albino Abca4−/− and agouti wild-type mice exhibited elevated bisretinoid levels as measured by high-performance liquid chromatography or noninvasively by quantitative fundus autofluorescence. Thinning of the outer nuclear layer, a parameter indicative of the loss of photoreceptor cell viability, was also reduced in DFP-treated albino Abca4−/−. In contrast to the effects of the Fe chelator, mice burdened with increased intracellular Fe in RPE due to deficiency in the Fe export proteins hephaestin and ceruloplasmin, presented with reduced bisretinoid levels. These findings indicate that intracellular Fe promotes bisretinoid oxidation and degradation. This interpretation was supported by experiments showing that DFP decreased the oxidative/degradation of the bisretinoid A2E in the presence of light and reduced cell death in cell-based experiments. Moreover, light-independent oxidation and degradation of A2E by Fenton chemistry products were evidenced by the consumption of A2E, release of dicarbonyls, and generation of oxidized A2E species in cell-free assays.
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Valizadeh A, Ghiasi R. Theoretical approach to the molecular structure, chemical reactivity, molecular orbital analysis, spectroscopic properties (IR, UV, NMR), and NBO analysis of deferiprone. J STRUCT CHEM+ 2017. [DOI: 10.1134/s002247661707006x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Yusuf IH, Shanks ME, Clouston P, MacLaren RE. A splice-site variant in FLVCR1 produces retinitis pigmentosa without posterior column ataxia. Ophthalmic Genet 2017; 39:263-267. [PMID: 29192808 DOI: 10.1080/13816810.2017.1408848] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
FLVCR1 (feline leukemia virus subgroup c receptor 1) is a transmembrane protein involved in the trafficking of intracellular heme. Homozygous variants in FLVCR1 have been described in association with a clinical syndrome of posterior column ataxia with retinitis pigmentosa (PCARP). Here, we describe a patient with non-syndromic retinitis pigmentosa homozygous for a splice-site variant in FLVCR1 (c.1092 + 5G>A) without evidence of posterior column ataxia or cerebellar degeneration. We suggest an association between intronic splice-site variants in FLVCR1 and the absence of posterior column degeneration and suggest a hypothesis to explain this observation. Should this association be proven, it would provide valuable prognostic information for patients. Retinal degeneration appears to be the sole clinical manifestation of this FLVCR1 variant; gene therapy approaches using an adeno-associated viral vector with sub-retinal delivery may therefore represent a therapeutic approach to halting retinal degeneration in this patient group.
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Affiliation(s)
- Imran H Yusuf
- a Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences , Oxford University , Oxford, UK.,b Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust , Oxford, UK
| | - Morag E Shanks
- c Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, The Churchill Hospital , Oxford , UK
| | - Penny Clouston
- c Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, The Churchill Hospital , Oxford , UK
| | - Robert E MacLaren
- a Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences , Oxford University , Oxford, UK.,b Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust , Oxford, UK
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Asthana A, Baksi S, Ashok A, Karmakar S, Mammadova N, Kokemuller R, Greenlee MH, Kong Q, Singh N. Prion protein facilitates retinal iron uptake and is cleaved at the β-site: Implications for retinal iron homeostasis in prion disorders. Sci Rep 2017; 7:9600. [PMID: 28851903 PMCID: PMC5575325 DOI: 10.1038/s41598-017-08821-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/17/2017] [Indexed: 12/22/2022] Open
Abstract
Prion disease-associated retinal degeneration is attributed to PrP-scrapie (PrPSc), a misfolded isoform of prion protein (PrPC) that accumulates in the neuroretina. However, a lack of temporal and spatial correlation between PrPSc and cytotoxicity suggests the contribution of host factors. We report retinal iron dyshomeostasis as one such factor. PrPC is expressed on the basolateral membrane of retinal-pigment-epithelial (RPE) cells, where it mediates uptake of iron by the neuroretina. Accordingly, the neuroretina of PrP-knock-out mice is iron-deficient. In RPE19 cells, silencing of PrPC decreases ferritin while over-expression upregulates ferritin and divalent-metal-transporter-1 (DMT-1), indicating PrPC-mediated iron uptake through DMT-1. Polarization of RPE19 cells results in upregulation of ferritin by ~10-fold and β-cleavage of PrPC, the latter likely to block further uptake of iron due to cleavage of the ferrireductase domain. A similar β-cleavage of PrPC is observed in mouse retinal lysates. Scrapie infection causes PrPSc accumulation and microglial activation, and surprisingly, upregulation of transferrin despite increased levels of ferritin. Notably, detergent-insoluble ferritin accumulates in RPE cells and correlates temporally with microglial activation, not PrPSc accumulation, suggesting that impaired uptake of iron by PrPSc combined with inflammation results in retinal iron-dyshomeostasis, a potentially toxic host response contributing to prion disease-associated pathology.
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Affiliation(s)
- Abhishek Asthana
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Shounak Baksi
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Ajay Ashok
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Shilpita Karmakar
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Najiba Mammadova
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa, 50010, USA
| | - Robyn Kokemuller
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa, 50010, USA
| | - Mary Heather Greenlee
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa, 50010, USA
| | - Qingzhong Kong
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Neena Singh
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, 44106, USA.
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Baumann B, Sterling J, Song Y, Song D, Fruttiger M, Gillies M, Shen W, Dunaief JL. Conditional Müller Cell Ablation Leads to Retinal Iron Accumulation. Invest Ophthalmol Vis Sci 2017; 58:4223-4234. [PMID: 28846772 PMCID: PMC5574447 DOI: 10.1167/iovs.17-21743] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 07/07/2017] [Indexed: 12/25/2022] Open
Abstract
Purpose Retinal iron accumulation is observed in a wide range of retinal degenerative diseases, including AMD. Previous work suggests that Müller glial cells may be important mediators of retinal iron transport, distribution, and regulation. A transgenic model of Müller cell loss recently demonstrated that primary Müller cell ablation leads to blood-retinal barrier leakage and photoreceptor degeneration, and it recapitulates clinical features observed in macular telangiectasia type 2 (MacTel2), a rare human disease that features Müller cell loss. We used this mouse model to determine the effect of Müller cell loss on retinal iron homeostasis. Methods Changes in total retinal iron levels after Müller cell ablation were measured using inductively coupled plasma mass spectrometry. Corresponding changes in the expression of iron flux and iron storage proteins were determined using quantitative PCR, Western analysis, and immunohistochemistry. Results Müller cell loss led to blood-retinal barrier breakdown and increased iron levels throughout the neurosensory retina. There were corresponding changes in mRNA and/or protein levels of ferritin, transferrin receptor, ferroportin, Zip8, and Zip14. There were also increased iron levels within the RPE of retinal sections from a patient with MacTel2 and both RPE and neurosensory retina of a patient with diabetic retinopathy, which, like MacTel2, causes retinal vascular leakage. Conclusion This study shows that Müller cells and the blood-retinal barrier play pivotal roles in the regulation of retinal iron homeostasis. The retinal iron accumulation resulting from blood-retinal barrier dysfunction may contribute to retinal degeneration in this model and in diseases such as MacTel2 and diabetic retinopathy.
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Affiliation(s)
- Bailey Baumann
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Jacob Sterling
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Ying Song
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Delu Song
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Marcus Fruttiger
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Mark Gillies
- Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Weiyong Shen
- Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Joshua L. Dunaief
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
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40
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Iron chelation for the treatment of uveitis. Med Hypotheses 2017; 103:1-4. [DOI: 10.1016/j.mehy.2017.03.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 02/04/2017] [Accepted: 03/06/2017] [Indexed: 12/21/2022]
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Sestak V, Stariat J, Cermanova J, Potuckova E, Chladek J, Roh J, Bures J, Jansova H, Prusa P, Sterba M, Micuda S, Simunek T, Kalinowski DS, Richardson DR, Kovarikova P. Novel and potent anti-tumor and anti-metastatic di-2-pyridylketone thiosemicarbazones demonstrate marked differences in pharmacology between the first and second generation lead agents. Oncotarget 2016; 6:42411-28. [PMID: 26623727 PMCID: PMC4767442 DOI: 10.18632/oncotarget.6389] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 11/11/2015] [Indexed: 01/15/2023] Open
Abstract
Di(2-pyridyl)ketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di(2-pyridyl)ketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) are novel, highly potent and selective anti-tumor and anti-metastatic drugs. Despite their structural similarity, these agents differ in their efficacy and toxicity in-vivo. Considering this, a comparison of their pharmacokinetic and pharmaco/toxico-dynamic properties was conducted to reveal if these factors are involved in their differential activity. Both compounds were administered to Wistar rats intravenously (2 mg/kg) and their metabolism and disposition were studied using UHPLC-MS/MS. The cytotoxicity of both thiosemicarbazones and their metabolites was also examined using MCF-7, HL-60 and HCT116 tumor cells and 3T3 fibroblasts and H9c2 cardiac myoblasts. Their intracellular iron-binding ability was characterized by the Calcein-AM assay and their iron mobilization efficacy was evaluated. In contrast to DpC, Dp44mT undergoes rapid demethylation in-vivo, which may be related to its markedly faster elimination (T1/2 = 1.7 h for Dp44mT vs. 10.7 h for DpC) and lower exposure. Incubation of these compounds with cancer cells or cardiac myoblasts did not result in any significant metabolism in-vitro. The metabolism of Dp44mT in-vivo resulted in decreased anti-cancer activity and toxicity. In conclusion, marked differences in the pharmacology of Dp44mT and DpC were observed and highlight the favorable pharmacokinetics of DpC for cancer treatment.
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Affiliation(s)
- Vit Sestak
- Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Jan Stariat
- Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Jolana Cermanova
- Department of Pharmacology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Simkova, Hradec Kralove, Czech Republic
| | - Eliska Potuckova
- Department of Biochemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Jaroslav Chladek
- Department of Pharmacology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Simkova, Hradec Kralove, Czech Republic
| | - Jaroslav Roh
- Department of Inorganic and Organic Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Jan Bures
- Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Hana Jansova
- Department of Biochemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Petr Prusa
- Department of Inorganic and Organic Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Martin Sterba
- Department of Pharmacology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Simkova, Hradec Kralove, Czech Republic
| | - Stanislav Micuda
- Department of Pharmacology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Simkova, Hradec Kralove, Czech Republic
| | - Tomas Simunek
- Department of Biochemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
| | - Danuta S Kalinowski
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - Des R Richardson
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - Petra Kovarikova
- Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho, Hradec Kralove, Czech Republic
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Song D, Kanu LN, Li Y, Kelly KL, Bhuyan RK, Aleman T, Morgan JIW, Dunaief JL. AMD-like retinopathy associated with intravenous iron. Exp Eye Res 2016; 151:122-33. [PMID: 27565570 DOI: 10.1016/j.exer.2016.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 07/28/2016] [Accepted: 08/17/2016] [Indexed: 12/19/2022]
Abstract
Iron accumulation in the retina is associated with the development of age-related macular degeneration (AMD). IV iron is a common method to treat iron deficiency anemia in adults, and its retinal manifestations have not hitherto been identified. To assess whether IV iron formulations can be retina-toxic, we generated a mouse model for iron-induced retinal damage. Male C57BL/6J mice were randomized into groups receiving IV iron-sucrose (+Fe) or 30% sucrose (-Fe). Iron levels in neurosensory retina (NSR), retinal pigment epithelium (RPE), and choroid were assessed using immunofluorescence, quantitative PCR, and the Perls' iron stain. Iron levels were most increased in the RPE and choroid while levels in the NSR did not differ significantly in +Fe mice compared to controls. Eyes from +Fe mice shared histological features with AMD, including Bruch's membrane (BrM) thickening with complement C3 deposition, as well as RPE hypertrophy and vacuolization. This focal degeneration correlated with areas of high choroidal iron levels. Ultrastructural analysis provided further detail of the RPE/photoreceptor outer segment vacuolization and Bruch's membrane thickening. Findings were correlated with a clinical case of a 43-year-old patient who developed numerous retinal drusen, the hallmark of AMD, within 11 months of IV iron therapy. Our results suggest that IV iron therapy may have the potential to induce or exacerbate a form of retinal degeneration. This retinal degeneration shares features with AMD, indicating the need for further study of AMD risk in patients receiving IV iron treatment.
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Affiliation(s)
- Delu Song
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Levi N Kanu
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Yafeng Li
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Kristen L Kelly
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Rupak K Bhuyan
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Tomas Aleman
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Jessica I W Morgan
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Joshua L Dunaief
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA.
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Butler MC, Sullivan JM. A Novel, Real-Time, In Vivo Mouse Retinal Imaging System. Invest Ophthalmol Vis Sci 2016; 56:7159-68. [PMID: 26551329 DOI: 10.1167/iovs.14-16370] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE To develop an efficient, low-cost instrument for robust real-time imaging of the mouse retina in vivo, and assess system capabilities by evaluating various animal models. METHODS Following multiple disappointing attempts to visualize the mouse retina during a subretinal injection using commercially available systems, we identified the key limitation to be inadequate illumination due to off axis illumination and poor optical train optimization. Therefore, we designed a paraxial illumination system for Greenough-type stereo dissecting microscope incorporating an optimized optical launch and an efficiently coupled fiber optic delivery system. Excitation and emission filters control spectral bandwidth. A color coupled-charged device (CCD) camera is coupled to the microscope for image capture. Although, field of view (FOV) is constrained by the small pupil aperture, the high optical power of the mouse eye, and the long working distance (needed for surgical manipulations), these limitations can be compensated by eye positioning in order to observe the entire retina. RESULTS The retinal imaging system delivers an adjustable narrow beam to the dilated pupil with minimal vignetting. The optic nerve, vasculature, and posterior pole are crisply visualized and the entire retina can be observed through eye positioning. Normal and degenerative retinal phenotypes can be followed over time. Subretinal or intraocular injection procedures are followed in real time. Real-time, intravenous fluorescein angiography for the live mouse has been achieved. CONCLUSIONS A novel device is established for real-time viewing and image capture of the small animal retina during subretinal injections for preclinical gene therapy studies.
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Affiliation(s)
- Mark C Butler
- Research Service, VA Western New York Healthcare System, Buffalo, New York, United States 2Department of Ophthalmology, Ross Eye Institute, University at Buffalo-SUNY, Buffalo, New York, United States
| | - Jack M Sullivan
- Research Service, VA Western New York Healthcare System, Buffalo, New York, United States 2Department of Ophthalmology, Ross Eye Institute, University at Buffalo-SUNY, Buffalo, New York, United States 3Department of Pharmacology/Toxicology, University at
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Song D, Wilson B, Zhao L, Bhuyan R, Bandyopadhyay M, Lyubarsky A, Yu C, Li Y, Kanu L, Miwa T, Song WC, Finnemann SC, Rohrer B, Dunaief JL. Retinal Pre-Conditioning by CD59a Knockout Protects against Light-Induced Photoreceptor Degeneration. PLoS One 2016; 11:e0166348. [PMID: 27893831 PMCID: PMC5125596 DOI: 10.1371/journal.pone.0166348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/27/2016] [Indexed: 11/25/2022] Open
Abstract
Complement dysregulation plays a key role in the pathogenesis of age-related macular degeneration (AMD), but the specific mechanisms are incompletely understood. Complement also potentiates retinal degeneration in the murine light damage model. To test the retinal function of CD59a, a complement inhibitor, CD59a knockout (KO) mice were used for light damage (LD) experiments. Retinal degeneration and function were compared in WT versus KO mice following light damage. Gene expression changes, endoplasmic reticulum (ER) stress, and glial cell activation were also compared. At baseline, the ERG responses and rhodopsin levels were lower in CD59aKO compared to wild-type (WT) mice. Following LD, the ERG responses were better preserved in CD59aKO compared to WT mice. Correspondingly, the number of photoreceptors was higher in CD59aKO retinas than WT controls after LD. Under normal light conditions, CD59aKO mice had higher levels than WT for GFAP immunostaining in Müller cells, mRNA and protein levels of two ER-stress markers, and neurotrophic factors. The reduction in photon capture, together with the neurotrophic factor upregulation, may explain the structural and functional protection against LD in the CD59aKO.
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Affiliation(s)
- Delu Song
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Brooks Wilson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC
| | - Liangliang Zhao
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
- Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Rupak Bhuyan
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | | | - Arkady Lyubarsky
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Chen Yu
- Center for Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY
| | - Yafeng Li
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Levi Kanu
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
| | - Takashi Miwa
- Department of Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Wen-Chao Song
- Department of Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Silvia C. Finnemann
- Center for Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC
- Research Service, Ralph H. Johnson VA Medical Center, Charleston, SC
- * E-mail: (JLD); (BR)
| | - Joshua L. Dunaief
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA
- * E-mail: (JLD); (BR)
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Picard E, Le Rouzic Q, Oudar A, Berdugo M, El Sanharawi M, Andrieu-Soler C, Naud MC, Jonet L, Latour C, Klein C, Galiacy S, Malecaze F, Coppin H, Roth MP, Jeanny JC, Courtois Y, Behar-Cohen F. Targeting iron-mediated retinal degeneration by local delivery of transferrin. Free Radic Biol Med 2015; 89:1105-21. [PMID: 26454080 DOI: 10.1016/j.freeradbiomed.2015.08.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 08/07/2015] [Accepted: 08/10/2015] [Indexed: 12/11/2022]
Abstract
Iron is essential for retinal function but contributes to oxidative stress-mediated degeneration. Iron retinal homeostasis is highly regulated and transferrin (Tf), a potent iron chelator, is endogenously secreted by retinal cells. In this study, therapeutic potential of a local Tf delivery was evaluated in animal models of retinal degeneration. After intravitreal injection, Tf spread rapidly within the retina and accumulated in photoreceptors and retinal pigment epithelium, before reaching the blood circulation. Tf injected in the vitreous prior and, to a lesser extent, after light-induced retinal degeneration, efficiently protected the retina histology and function. We found an association between Tf treatment and the modulation of iron homeostasis resulting in a decrease of iron content and oxidative stress marker. The immunomodulation function of Tf could be seen through a reduction in macrophage/microglial activation as well as modulated inflammation responses. In a mouse model of hemochromatosis, Tf had the capacity to clear abnormal iron accumulation from retinas. And in the slow P23H rat model of retinal degeneration, a sustained release of Tf in the vitreous via non-viral gene therapy efficently slowed-down the photoreceptors death and preserved their function. These results clearly demonstrate the synergistic neuroprotective roles of Tf against retinal degeneration and allow identify Tf as an innovative and not toxic therapy for retinal diseases associated with oxidative stress.
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Affiliation(s)
- Emilie Picard
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France.
| | - Quentin Le Rouzic
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Antonin Oudar
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Marianne Berdugo
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Mohamed El Sanharawi
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Charlotte Andrieu-Soler
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Marie-Christine Naud
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Laurent Jonet
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Chloé Latour
- INSERM, U1043, Toulouse, France; CNRS, U5282, Toulouse, France; Université de Toulouse, UPS, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France
| | - Christophe Klein
- INSERM, U1138, CICC, Université René Descartes Sorbonne Paris Cité, Université Pierre et Marie Curie Paris, Centre de Recherche des Cordeliers, Paris, France
| | - Stéphane Galiacy
- INSERM U563, Centre de Physiopathologie de Toulouse Purpan, Toulouse, France; Department of Ophthalmology, Purpan Hospital, Toulouse, France
| | - François Malecaze
- INSERM U563, Centre de Physiopathologie de Toulouse Purpan, Toulouse, France; Department of Ophthalmology, Purpan Hospital, Toulouse, France
| | - Hélène Coppin
- INSERM, U1043, Toulouse, France; CNRS, U5282, Toulouse, France; Université de Toulouse, UPS, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France
| | - Marie-Paule Roth
- INSERM, U1043, Toulouse, France; CNRS, U5282, Toulouse, France; Université de Toulouse, UPS, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France
| | - Jean-Claude Jeanny
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Yves Courtois
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France
| | - Francine Behar-Cohen
- INSERM, UMRS 1138, team Behar-Cohen, From physiopathology of ocular diseases to clinical development, Centre de Recherche des Cordeliers, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Université René Descartes, Centre de Recherche des Cordeliers UMRS 1138, Paris, France; Jules Gonin Ophthalmic Hospital, Lausanne, Switzerland
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Bhoiwala DL, Song Y, Cwanger A, Clark E, Zhao LL, Wang C, Li Y, Song D, Dunaief JL. CD1 Mouse Retina Is Shielded From Iron Overload Caused by a High Iron Diet. Invest Ophthalmol Vis Sci 2015; 56:5344-52. [PMID: 26275132 DOI: 10.1167/iovs.15-17026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE High RPE iron levels have been associated with age-related macular degeneration. Mutation of the ferroxidase ceruloplasmin leads to RPE iron accumulation and degeneration in patients with aceruloplasminemia; mice lacking ceruloplasmin and its homolog hephaestin have a similar RPE degeneration. To determine whether a high iron diet (HID) could cause RPE iron accumulation, possibly contributing to RPE oxidative stress in AMD, we tested the effect of dietary iron on mouse RPE iron. METHODS Male CD1 strain mice were fed either a standard iron diet (SID) or the same diet with extra iron added (HID) for either 3 months or 10 months. Mice were analyzed with immunofluorescence and Perls' histochemical iron stain to assess iron levels. Levels of ferritin, transferrin receptor, and oxidative stress gene mRNAs were measured by quantitative PCR (qPCR) in neural retina (NR) and isolated RPE. Morphology was assessed in plastic sections. RESULTS Ferritin immunoreactivity demonstrated a modest increase in the RPE in 10-month HID mice. Analysis by qPCR showed changes in mRNA levels of iron-responsive genes, indicating moderately increased iron in the RPE of 10-month HID mice. However, even by age 18 months, there was no Perls' signal in the retina or RPE and no retinal degeneration. CONCLUSIONS These findings indicate that iron absorbed from the diet can modestly increase the level of iron deposition in the wild-type mouse RPE without causing RPE or retinal degeneration. This suggests regulation of retinal iron uptake at the blood-retinal barriers.
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Affiliation(s)
- Devang L Bhoiwala
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States 2Albany Medical College, Albany, New York, United States
| | - Ying Song
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alyssa Cwanger
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Esther Clark
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Liang-liang Zhao
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States 3Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Chenguang Wang
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States 3Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Yafeng Li
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Delu Song
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Joshua L Dunaief
- F. M. Kirby Center for Molecular Ophthalmology Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Song D, Song J, Wang C, Li Y, Dunaief JL. Berberine protects against light-induced photoreceptor degeneration in the mouse retina. Exp Eye Res 2015; 145:1-9. [PMID: 26475979 DOI: 10.1016/j.exer.2015.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 09/29/2015] [Accepted: 10/05/2015] [Indexed: 02/07/2023]
Abstract
Oxidative stress and inflammation play key roles in the light damage (LD) model of photoreceptor degeneration, as well as in age-related macular degeneration (AMD). We sought to investigate whether Berberine (BBR), an antioxidant herb extract, would protect the retina against light-induced degeneration. To accomplish this, Balb/c mice were treated with BBR or PBS via gavage for 7 days, and then were placed in constant cool white light-emitting diode (LED) light (10,000 lux) for 4 h. Retinal function and degeneration were evaluated by histology, electroretinography (ERG) and optical coherence tomography (OCT) at 7d after LD. Additionally, mRNA levels of cell-type specific, antioxidant, and inflammatory genes were compared 7d after LD. Photoreceptor DNA fragmentation was assessed via the terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay. LD resulted in substantial photoreceptor-specific cell death. Histological analysis using plastic sections showed dosing with BBR preserved photoreceptors. The ERG analysis demonstrated functional protection by BBR in rod-b, -a, and cone-b waves. In OCT images, mice receiving PBS showed severe thinning and disorganization of the photoreceptor layer 7 days after LD, whereas mice treated with BBR had significantly less thinning and disorganization. Consistent with OCT results, the mRNA levels of Rho in the NSR, and Rpe65 and Mct3 in the RPE, were significantly higher in mice treated with BBR. The numbers of TUNEL-positive photoreceptors were significantly decreased in BBR-treated mice. The retinal mRNA levels of oxidative stress genes, the number of microglia/macrophages, and the malondialdehyde (MDA) immunolabeling were significantly lower in BBR-treated mice compared to controls 48 h after LD, which indicates oxidative stress was reduced by BBR in light-damaged eyes. In conclusion, systemic BBR is protective against light-induced retinal degeneration associated with diminished oxidative stress in the retina. These results suggest that BBR may be protective against retinal diseases involving oxidative stress.
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Affiliation(s)
- Delu Song
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, United States
| | - Jiantao Song
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, United States; Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Chenguang Wang
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, United States; Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Yafeng Li
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, United States
| | - Joshua L Dunaief
- The F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, United States.
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Bhoiwala DL, Dunaief JL. Retinal abnormalities in β-thalassemia major. Surv Ophthalmol 2015; 61:33-50. [PMID: 26325202 DOI: 10.1016/j.survophthal.2015.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 08/15/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
Abstract
Patients with beta (β)-thalassemia (β-TM: β-thalassemia major, β-TI: β-thalassemia intermedia) have a variety of complications that may affect all organs, including the eye. Ocular abnormalities include retinal pigment epithelial degeneration, angioid streaks, venous tortuosity, night blindness, visual field defects, decreased visual acuity, color vision abnormalities, and acute visual loss. Patients with β-thalassemia major are transfusion dependent and require iron chelation therapy to survive. Retinal degeneration may result from either retinal iron accumulation from transfusion-induced iron overload or retinal toxicity induced by iron chelation therapy. Some who were never treated with iron chelation therapy exhibited retinopathy, and others receiving iron chelation therapy had chelator-induced retinopathy. We will focus on retinal abnormalities present in individuals with β-thalassemia major viewed in light of new findings on the mechanisms and manifestations of retinal iron toxicity.
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Affiliation(s)
- Devang L Bhoiwala
- Department of Ophthalmology, F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Philadelphia, Pennsylvania, USA; Department of Ophthalmology, Albany Medical College, Albany, New York, USA
| | - Joshua L Dunaief
- Department of Ophthalmology, F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Philadelphia, Pennsylvania, USA.
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