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Wishart TFL, Flokis M, Shu DY, Das SJ, Lovicu FJ. Hallmarks of lens aging and cataractogenesis. Exp Eye Res 2021; 210:108709. [PMID: 34339681 DOI: 10.1016/j.exer.2021.108709] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/05/2021] [Accepted: 07/26/2021] [Indexed: 12/18/2022]
Abstract
Lens homeostasis and transparency are dependent on the function and intercellular communication of its epithelia. While the lens epithelium is uniquely equipped with functional repair systems to withstand reactive oxygen species (ROS)-mediated oxidative insult, ROS are not necessarily detrimental to lens cells. Lens aging, and the onset of pathogenesis leading to cataract share an underlying theme; a progressive breakdown of oxidative stress repair systems driving a pro-oxidant shift in the intracellular environment, with cumulative ROS-induced damage to lens cell biomolecules leading to cellular dysfunction and pathology. Here we provide an overview of our current understanding of the sources and essential functions of lens ROS, antioxidative defenses, and changes in the major regulatory systems that serve to maintain the finely tuned balance of oxidative signaling vs. oxidative stress in lens cells. Age-related breakdown of these redox homeostasis systems in the lens leads to the onset of cataractogenesis. We propose eight candidate hallmarks that represent common denominators of aging and cataractogenesis in the mammalian lens: oxidative stress, altered cell signaling, loss of proteostasis, mitochondrial dysfunction, dysregulated ion homeostasis, cell senescence, genomic instability and intrinsic apoptotic cell death.
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Affiliation(s)
| | - Mary Flokis
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Daisy Y Shu
- School of Medical Sciences, The University of Sydney, NSW, Australia; Save Sight Institute, The University of Sydney, NSW, Australia; Schepens Eye Research Institute of Mass Eye and Ear. Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Shannon J Das
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Frank J Lovicu
- School of Medical Sciences, The University of Sydney, NSW, Australia; Save Sight Institute, The University of Sydney, NSW, Australia.
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Broadhead GK, Hong T, Bahrami B, Flood V, Liew G, Chang AA. Diet and risk of visual impairment: a review of dietary factors and risk of common causes of visual impairment. Nutr Rev 2020; 79:636-650. [PMID: 33051676 DOI: 10.1093/nutrit/nuaa100] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Age-related macular degeneration, diabetic retinopathy, cataract, and glaucoma remain the leading causes of visual impairment in developed nations, resulting in a substantial treatment burden on sufferers and health care systems. Despite significant advances in diagnostic testing and therapeutics, population-based strategies to reduce the burden of these diseases remain limited. However, there is some evidence that these diseases may share overlapping risk factors, particularly in regard to dietary intake and antioxidant status, and it is thus possible that dietary modification may reduce both the prevalence and severity of these conditions. In particular, dietary intake of green leafy vegetables, hyperglycemia/glycemia index, and omega-3 fatty acid intake, as well as overall dietary patterns, may affect risk of one or more of these conditions. In this review, we analyse the evidence for dietary intake and the association with these conditions, and provide insights into possible modifications that may thus simultaneously reduce the risk of visual impairment from multiple causes, including improving dietary intake of green leafy vegetables and reducing dietary glycemic index, both of which have been associated with a decreased risk of multiple causes of visual impairment.
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Affiliation(s)
- Geoffrey K Broadhead
- Save Sight Institute, University of Sydney, Sydney, NSW, Australia.,Sydney Institute of Vision Science, Sydney, NSW, Australia.,Sydney Institute of Vision Science, Sydney, NSW, Australia
| | - Thomas Hong
- Sydney Institute of Vision Science, Sydney, NSW, Australia
| | - Bobak Bahrami
- Save Sight Institute, University of Sydney, Sydney, NSW, Australia.,Sydney Institute of Vision Science, Sydney, NSW, Australia.,Sydney Institute of Vision Science, Sydney, NSW, Australia
| | - Victoria Flood
- Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Western Sydney Local Health District, Sydney, NSW, Australia.,Westmead Hospital, Western Sydney Local Health District, Westmead, NSW, Australia
| | - Gerald Liew
- Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, NSW, Australia
| | - Andrew A Chang
- Save Sight Institute, University of Sydney, Sydney, NSW, Australia.,Sydney Institute of Vision Science, Sydney, NSW, Australia.,Sydney Institute of Vision Science, Sydney, NSW, Australia
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Jia Y, Dai J, Zhang L, Xia H. Effect of Exogenous Zinc on MsrB1 Expression and Protein Oxidation in Human Lens Epithelial Cells. Biol Trace Elem Res 2019; 190:60-64. [PMID: 30306419 DOI: 10.1007/s12011-018-1543-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/04/2018] [Indexed: 11/30/2022]
Abstract
Aging has been related to zinc deficiency, resulting in protein oxidation and age-related decline of methionine sulfoxide reductase (Msr) activity. This study was designed to investigate the levels of methionine sulfoxide reductase B1 (MsrB1) mRNA and oxidized proteins in human lens epithelial (hLE) cells after treatment with exogenous zinc. The role of exogenous zinc in regulation of MsrB1 gene expression and protein oxidation in hLE cells was studied by MTT assay, oxidized protein measurement kit, and real-time PCR. The results showed that hLE cell viability was significantly decreased by MsrB1 gene knockdown or peroxynitrite (ONOO-) treatment, while it was significantly increased after treatment with exogenous zinc (P < 0.05). Protein carbonyl content in hLE cell by MsrB1 gene knockdown or ONOO- treatment was significantly decreased after treatment with ZnSO4 (P < 0.01). And exogenous zinc could increase the level of MsrB1 in hLE cell under normal (P < 0.001) and oxidative stress (P < 0.01) conditions. In conclusion, exogenous zinc could protect hLE cells against MsrB1 gene knockdown or ONOO--induced cell death by upregulation of MsrB1 involved in the elimination of reactive oxygen species (ROS) and oxidized proteins.
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Affiliation(s)
- Yi Jia
- Department of Chemical Biology, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, Guizhou, People's Republic of China.
| | - Jie Dai
- Department of Chemical Biology, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, Guizhou, People's Republic of China
| | - Liangliang Zhang
- Department of Chemical Biology, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, Guizhou, People's Republic of China
| | - Huan Xia
- Department of Chemical Biology, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, Guizhou, People's Republic of China
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Hori Y, Yoshikawa T, Tsuji N, Bamba T, Aso Y, Kudou M, Uchida Y, Takagi M, Harada K, Hirata K. Phytochelatins inhibit the metal-induced aggregation of alpha-crystallin. J Biosci Bioeng 2009; 107:173-6. [PMID: 19217556 DOI: 10.1016/j.jbiosc.2008.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Accepted: 09/30/2008] [Indexed: 10/20/2022]
Abstract
Phytochelatins (PCs) are heavy-metal-binding peptides found in some eukaryotes. This study investigates the use of plant-derived PCs for the inhibition of metal-induced protein aggregation. The results of this study show that PCs inhibit zinc-induced alpha-crystallin aggregation, and suggest that PCs might be useful as anti-cataract agents.
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Affiliation(s)
- Yasuhisa Hori
- Department of Environmental Biotechnology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
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