1
|
Wei Z, Hao C, Radeen KR, Srinivasagan R, Chen JK, Sharma S, McGee-Lawrence ME, Hamrick MW, Monnier VM, Fan X. Prevention of age-related truncation of γ-glutamylcysteine ligase catalytic subunit (GCLC) delays cataract formation. SCIENCE ADVANCES 2024; 10:eadl1088. [PMID: 38669339 PMCID: PMC11051666 DOI: 10.1126/sciadv.adl1088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 03/22/2024] [Indexed: 04/28/2024]
Abstract
A sharp drop in lenticular glutathione (GSH) plays a pivotal role in age-related cataract (ARC) formation. Despite recognizing GSH's importance in lens defense for decades, its decline with age remains puzzling. Our recent study revealed an age-related truncation affecting the essential GSH biosynthesis enzyme, the γ-glutamylcysteine ligase catalytic subunit (GCLC), at aspartate residue 499. Intriguingly, these truncated GCLC fragments compete with full-length GCLC in forming a heterocomplex with the modifier subunit (GCLM) but exhibit markedly reduced enzymatic activity. Crucially, using an aspartate-to-glutamate mutation knock-in (D499E-KI) mouse model that blocks GCLC truncation, we observed a notable delay in ARC formation compared to WT mice: Nearly 50% of D499E-KI mice remained cataract-free versus ~20% of the WT mice at their age of 20 months. Our findings concerning age-related GCLC truncation might be the key to understanding the profound reduction in lens GSH with age. By halting GCLC truncation, we can rejuvenate lens GSH levels and considerably postpone cataract onset.
Collapse
Affiliation(s)
- Zongbo Wei
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Caili Hao
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Kazi Rafsan Radeen
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Ramkumar Srinivasagan
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jian-Kang Chen
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Shruti Sharma
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Meghan E. McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Mark W. Hamrick
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Vincent M. Monnier
- Department of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Xingjun Fan
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| |
Collapse
|
2
|
Hong C, Huang Y, Cao S, Wang L, Yang X, Hu S, Gao K, Jiang Z, Xiao H. Accurate models and nutritional strategies for specific oxidative stress factors: Does the dose matter in swine production? J Anim Sci Biotechnol 2024; 15:11. [PMID: 38273345 PMCID: PMC10811888 DOI: 10.1186/s40104-023-00964-8] [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: 07/12/2023] [Accepted: 12/01/2023] [Indexed: 01/27/2024] Open
Abstract
Oxidative stress has been associated with a number of physiological problems in swine, including reduced production efficiency. Recently, although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production, it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors. Here, we discuss the dose and dose intensity of the causes of oxidative stress involving physiological, environmental and dietary factors, recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.
Collapse
Affiliation(s)
- Changming Hong
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Yujian Huang
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Shuting Cao
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Li Wang
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Xuefen Yang
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Shenglan Hu
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Kaiguo Gao
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Zongyong Jiang
- State Key Laboratory of Swine and Poultry Breeding Industry, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition, Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Hao Xiao
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, 1 Dafeng 1st Street, Guangzhou, 510640, China.
| |
Collapse
|
3
|
Bejarano E, Weinberg J, Clark M, Taylor A, Rowan S, Whitcomb EA. Redox Regulation in Age-Related Cataracts: Roles for Glutathione, Vitamin C, and the NRF2 Signaling Pathway. Nutrients 2023; 15:3375. [PMID: 37571310 PMCID: PMC10421530 DOI: 10.3390/nu15153375] [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: 06/29/2023] [Revised: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
Age is the biggest risk factor for cataracts, and aberrant oxidative modifications are correlated with age-related cataracts, suggesting that proper redox regulation is important for lens clarity. The lens has very high levels of antioxidants, including ascorbate and glutathione that aid in keeping the lens clear, at least in young animals and humans. We summarize current functional and genetic data supporting the hypothesis that impaired regulation of oxidative stress leads to redox dysregulation and cataract. We will focus on the essential endogenous antioxidant glutathione and the exogenous antioxidant vitamin C/ascorbate. Additionally, gene expression in response to oxidative stress is regulated in part by the transcription factor NRF2 (nuclear factor erythroid 2-related factor 2 [NFE2L2]), thus we will summarize our data regarding cataracts in Nrf2-/- mice. In this work, we discuss the function and integration of these capacities with the objective of maintaining lens clarity.
Collapse
Affiliation(s)
- Eloy Bejarano
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA; (E.B.); (J.W.); (M.C.); (A.T.); (S.R.)
- School of Health Sciences and Veterinary, Universidad CEU Cardenal Herrera, CEU Universities, 46113 Valencia, Spain
| | - Jasper Weinberg
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA; (E.B.); (J.W.); (M.C.); (A.T.); (S.R.)
| | - Madison Clark
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA; (E.B.); (J.W.); (M.C.); (A.T.); (S.R.)
| | - Allen Taylor
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA; (E.B.); (J.W.); (M.C.); (A.T.); (S.R.)
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA 02111, USA
- Department of Ophthalmology, School of Medicine, Tufts University, Boston, MA 02111, USA
- Department of Developmental, Chemical and Molecular Biology, Tufts University, Boston, MA 02111, USA
| | - Sheldon Rowan
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA; (E.B.); (J.W.); (M.C.); (A.T.); (S.R.)
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA 02111, USA
- Department of Ophthalmology, School of Medicine, Tufts University, Boston, MA 02111, USA
| | - Elizabeth A. Whitcomb
- JM-USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA; (E.B.); (J.W.); (M.C.); (A.T.); (S.R.)
| |
Collapse
|
4
|
Lou MF. Glutathione and Glutaredoxin in Redox Regulation and Cell Signaling of the Lens. Antioxidants (Basel) 2022; 11:1973. [PMID: 36290696 PMCID: PMC9598519 DOI: 10.3390/antiox11101973] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/20/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
The ocular lens has a very high content of the antioxidant glutathione (GSH) and the enzymes that can recycle its oxidized form, glutathione disulfide (GSSG), for further use. It can be synthesized in the lens and, in part, transported from the neighboring anterior aqueous humor and posterior vitreous body. GSH is known to protect the thiols of the structural lens crystallin proteins from oxidation by reactive oxygen species (ROS) so the lens can maintain its transparency for proper visual function. Age-related lens opacity or senile cataract is the major visual impairment in the general population, and its cause is closely associated with aging and a constant exposure to environmental oxidative stress, such as ultraviolet light and the metabolic end product, H2O2. The mechanism for senile cataractogenesis has been hypothesized as the results of oxidation-induced protein-thiol mixed disulfide formation, such as protein-S-S-glutathione and protein-S-S-cysteine mixed disulfides, which if not reduced in time, can change the protein conformation to allow cascading modifications of various kinds leading to protein-protein aggregation and insolubilization. The consequence of such changes in lens structural proteins is lens opacity. Besides GSH, the lens has several antioxidation defense enzymes that can repair oxidation damage. One of the specific redox regulating enzymes that has been recently identified is thioltransferase (glutaredoxin 1), which works in concert with GSH, to reduce the oxidative stress as well as to regulate thiol/disulfide redox balance by preventing protein-thiol mixed disulfide accumulation in the lens. This oxidation-resistant and inducible enzyme has multiple physiological functions. In addition to protecting structural proteins and metabolic enzymes, it is able to regulate the redox signaling of the cells during growth factor-stimulated cell proliferation and other cellular functions. This review article focuses on describing the redox regulating functions of GSH and the thioltransferase enzyme in the ocular lens.
Collapse
Affiliation(s)
- Marjorie F. Lou
- School of Veterinary Medicine and Biomedical Sciences, Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68583, USA;
- Department of Ophthalmology, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| |
Collapse
|
5
|
Extensive Thiol Profiling for Assessment of Intracellular Redox Status in Cultured Cells by HPLC-MS/MS. Antioxidants (Basel) 2021; 11:antiox11010024. [PMID: 35052528 PMCID: PMC8773739 DOI: 10.3390/antiox11010024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 11/26/2022] Open
Abstract
Oxidative stress may contribute to the pathology of many diseases, and endogenous thiols, especially glutathione (GSH) and its metabolites, play essential roles in the maintenance of normal redox status. Understanding how these metabolites change in response to oxidative insult can provide key insights into potential methods of prevention and treatment. Most existing methodologies focus only on the GSH/GSH disulfide (GSSG) redox couple, but GSH regulation is highly complex and depends on several pathways with multiple redox-active sulfur-containing species. In order to more fully characterize thiol redox status in response to oxidative insult, a high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) method was developed to simultaneously determine seven sulfur-containing metabolites, generating a panel that systematically examines several pathways involved in thiol metabolism and oxidative stress responses. The sensitivity (LOQ as low as 0.01 ng/mL), accuracy (88–126% spike recovery), and precision (≤12% RSD) were comparable or superior to those of existing methods. Additionally, the method was used to compare the baseline thiol profiles and oxidative stress responses of cell lines derived from different tissues. The results revealed a previously unreported response to oxidative stress in lens epithelial (B3) cells, which may be exploited as a new therapeutic target for oxidative-stress-related ocular diseases. Further application of this method may uncover new pathways involved in oxidative-stress-related diseases and endogenous defense mechanisms.
Collapse
|
6
|
Huynh TPN, Bowater RP, Bernuzzi F, Saha S, Wormstone IM. GSH Levels Serve As a Biological Redox Switch Regulating Sulforaphane-Induced Cell Fate in Human Lens Cells. Invest Ophthalmol Vis Sci 2021; 62:2. [PMID: 34854886 PMCID: PMC8648057 DOI: 10.1167/iovs.62.15.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/08/2021] [Indexed: 01/10/2023] Open
Abstract
Purpose Sulforaphane (SFN) is a therapeutic phytochemical agent for many health conditions. SFN-induced cytotoxicity is shown to have promise in preventing posterior capsule opacification (PCO). In the current study, we aimed to elucidate key processes and mechanisms linking SFN treatment to lens cell death. Methods The human lens epithelial cell line FHL124 and central anterior epithelium were used as experimental models. Cell death was assessed by microscopic observation and cell damage/viability assays. Gene or protein levels were assessed by TaqMan RT-PCR or immunoblotting. Mitochondrial networks and DNA damage were assessed by immunofluorescence. Mitochondrial membrane potential, activating transcription factor 6 (ATF6) activity, ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG), and glutathione reductase (GR) activity were measured using different light reporter assays. SFN metabolites were analyzed by LC-MS/MS. Results Treatment with N-acetylcysteine (NAC), a reactive oxygen species scavenger, prevented SFN-induced cell death in both models. NAC also significantly protected FHL124 cells from SFN-induced mitochondrial dysfunctions, endoplasmic reticulum stress (ERS), DNA damage and autophagy. SFN significantly depleted GSH, the major antioxidant in the eye, and reduced GR activity, despite doubling its protein levels. The most abundant SFN conjugate detected in lens cells following SFN application was SFN-GSH. The addition of GSH protected lens cells from all SFN-induced cellular events. Conclusions SFN depletes GSH levels in lens cells through conjugation and inhibition of GR activity. This leads to increased reactive oxygen species and oxidative stress that trigger mitochondrial dysfunction, ERS, autophagy, and DNA damage, leading to cell death. In summary, the work presented provides a mechanistic understanding to support the therapeutic application of SFN for PCO and other disorders.
Collapse
Affiliation(s)
| | - Richard P. Bowater
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Federico Bernuzzi
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
- Quadram Institute, Norwich Research Park, Norwich, United Kingdom
| | - Shikha Saha
- Quadram Institute, Norwich Research Park, Norwich, United Kingdom
| | - I. Michael Wormstone
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| |
Collapse
|
7
|
Martis RM, Li B, Donaldson PJ, Lim JCH. Early Onset of Age-Related Cataracts in Cystine/Glutamate Antiporter Knockout Mice. Invest Ophthalmol Vis Sci 2021; 62:23. [PMID: 34156426 PMCID: PMC8237109 DOI: 10.1167/iovs.62.7.23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Purpose The purpose of this study was to determine the importance of the xCT is a subunit. The cystine/glutamate antiporter is actually system xc-xCT subunit of the cystine/glutamate antiporter in maintaining redox balance by investigating the effects of the loss of xCT on lens transparency and cystine/cysteine balance in the aqueous humour. Methods C57Bl/6 wild-type and xCT knockout mice at five age groups (6 weeks to 12 months) were used. Lens transparency was examined using a slit-lamp and morphological changes visualized by immunolabelling and confocal microscopy. Quantification of glutathione in lenses and cysteine and cystine levels in the aqueous was conducted by liquid chromatography tandem mass spectrometry (LC-MS/MS). Results Slit-lamp examinations revealed that 3-month-old wild-type mice and xCT knockout mice lenses exhibited an anterior localized cataract. The frequency of this cataract significantly increased in the knockout mice compared to the wild-type mice. Morphological studies revealed a localized swelling of the lens fiber cells at the anterior pole. Glutathione levels in whole lenses were similar between wild-type and knockout mice. However, glutathione levels were significantly decreased at 3 months in the knockout mice in the lens epithelium compared to the wild-type mice. Aqueous cysteine levels remained similar between wild-type and knockout mice at all age groups, whereas cystine levels were significantly increased in 3-, 9-, and 12-month-old knockout mice compared to wild-type mice. Conclusions Loss of xCT resulted in the depletion of glutathione in the epithelium and an oxidative shift in the cysteine/cystine ratio of the aqueous. Together, these oxidative changes may contribute to the accelerated development of an anterior cataract in knockout mice, which appears to be a normal feature of aging in wild-type mice.
Collapse
Affiliation(s)
- Renita Maria Martis
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.,New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Bo Li
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.,New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Paul James Donaldson
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.,New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Julie Ching-Hsia Lim
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.,New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| |
Collapse
|
8
|
Kumar D, Lim JC, Donaldson PJ. A link between maternal malnutrition and depletion of glutathione in the developing lens: a possible explanation for idiopathic childhood cataract? Clin Exp Optom 2021; 96:523-8. [DOI: 10.1111/cxo.12076] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 11/21/2012] [Accepted: 11/29/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- Deepa Kumar
- Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand,
- New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand,
| | - Julie C Lim
- Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand,
- New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand,
| | - Paul J Donaldson
- New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand,
- School of Medical Sciences, University of Auckland, Auckland, New Zealand,
| |
Collapse
|
9
|
Lim JC, Grey AC, Zahraei A, Donaldson PJ. Age‐dependent changes in glutathione metabolism pathways in the lens: New insights into therapeutic strategies to prevent cataract formation—A review. Clin Exp Ophthalmol 2020; 48:1031-1042. [DOI: 10.1111/ceo.13801] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/15/2020] [Accepted: 05/22/2020] [Indexed: 12/29/2022]
Affiliation(s)
- Julie C. Lim
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Center University of Auckland Auckland New Zealand
| | - Angus C. Grey
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Center University of Auckland Auckland New Zealand
| | - Ali Zahraei
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Center University of Auckland Auckland New Zealand
| | - Paul J. Donaldson
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Center University of Auckland Auckland New Zealand
| |
Collapse
|
10
|
Zhou Y, Li L, Li S, Li S, Zhao M, Zhou Q, Gong X, Yang J, Chang J. Autoregenerative redox nanoparticles as an antioxidant and glycation inhibitor for palliation of diabetic cataracts. NANOSCALE 2019; 11:13126-13138. [PMID: 31268450 DOI: 10.1039/c9nr02350j] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Diabetic cataracts (DCs) are one of the most common ocular complications of diabetes, and easily causes blindness among diabetics. However, there are limited drugs to delay and prevent DCs. Research studies indicate that oxidative damage of the crystalline lens and nonenzymatic glycosylation of the lens protein play a key role in the pathogenesis of DCs. Hence, we developed a kind of autoregenerative redox nanoparticle, which was CeO2 NPs coated with PEG-PLGA (PCNPs). We first found that PCNPs could work not only as an antioxidant to protect lens epithelial cells from oxidative stress based on the repetitive elimination of reactive oxygen species (ROS), but also as a glycation inhibitor effectively restraining α-crystallin glycation and crosslinking, thereby keeping the lens transparent and alleviating DCs. Experimental results successfully validated the fact that the PCNPs were able to operate in eyes for a long time to attenuate lens opacity. We expect that this strategy will provide promising potential for the treatment of DCs.
Collapse
Affiliation(s)
- Yurui Zhou
- School of Life Sciences, Tianjin University, Tianjin Engineering Research Center for Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin 300072, China.
| | - Lu Li
- School of Life Sciences, Tianjin University, Tianjin Engineering Research Center for Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin 300072, China.
| | - Shenghui Li
- Key Laboratory of Post-Neurotrauma Neurorepair and Regeneration in Central Nervous System Ministry of Education in China and Tianjin, Tianjin Neurological Institute, Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Shufei Li
- Department of Toxicology, Tianjin Center for Disease Control and Prevention, Tianjin 300011, China
| | - Miao Zhao
- Department of Toxicology, Tianjin Center for Disease Control and Prevention, Tianjin 300011, China
| | - Qinghong Zhou
- Department of Toxicology, Tianjin Center for Disease Control and Prevention, Tianjin 300011, China
| | - Xiaoqun Gong
- School of Life Sciences, Tianjin University, Tianjin Engineering Research Center for Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin 300072, China.
| | - Jin Yang
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University Myopia Key Laboratory of Health PR China, Shanghai, 200031, China.
| | - Jin Chang
- School of Life Sciences, Tianjin University, Tianjin Engineering Research Center for Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin 300072, China.
| |
Collapse
|
11
|
Umapathy A, Li B, Donaldson PJ, Lim JC. Functional characterisation of glutathione export from the rat lens. Exp Eye Res 2018; 166:151-159. [DOI: 10.1016/j.exer.2017.10.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/19/2017] [Accepted: 10/10/2017] [Indexed: 02/08/2023]
|
12
|
Lim JC, Perwick RD, Li B, Donaldson PJ. Comparison of the expression and spatial localization of glucose transporters in the rat, bovine and human lens. Exp Eye Res 2017. [PMID: 28625822 DOI: 10.1016/j.exer.2017.06.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The energy required to drive lens transparency is derived from the metabolism of glucose. In the lens, the uptake of glucose is likely to involve either facilitative glucose uptake mediated by members of the GLUT family or Na+ dependent glucose uptake via members of the SGLT family, or both. While GLUT1 and GLUT3 have previously been identified in the rat lens, the expression of SGLTs is unknown. Since antibodies directed against the N and C-terminal epitopes of the GLUT and SGLT family are now commercially available, the purpose of this study is to extend our screening of glucose transporters in the rat lens to include the SGLTs and compare the expression profiles of GLUTs and SGLTs in the different regions of the rat, bovine and human lens. Using a combination of reverse transcriptase PCR, western blotting and immunohistochemistry, we have shown that GLUT1 appears to be the predominant glucose transporter in the rat lens since it was expressed in all regions of the lens. In contrast GLUT3, SGLT1 and SGLT2 had more restricted expression patterns and were only found localised to the inner cortex and core regions of the rat lens. GLUT1 was the only transporter found in the epithelium and appears to exist as a full length form in this region, while in differentiating fiber cells; GLUT1 appears to undergo a modification to its N-terminus. Translating our work to bovine and human lenses revealed that GLUT1 is the only glucose transporter expressed in bovine and human lenses. While GLUT1 in the bovine lens appears to be unmodified throughout the entire lens, GLUT1 in human lenses appears to be N-terminally modified in all regions, including the epithelium. Finally, it appears that GLUT1 expression is maintained in all regions of the human lens with increasing age indicating that there is no further regional or age-dependent processing of GLUT1 in the human lens. Taken together, these studies have identified GLUT1 to be the primary transporter that mediates glucose uptake in the rat, bovine and human lens.
Collapse
Affiliation(s)
- Julie C Lim
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Centre, University of Auckland, New Zealand.
| | - Rebecca D Perwick
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Bo Li
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Paul J Donaldson
- Department of Physiology, School of Medical Sciences, New Zealand National Eye Centre, University of Auckland, New Zealand
| |
Collapse
|
13
|
Whitson JA, Sell DR, Goodman MC, Monnier VM, Fan X. Evidence of Dual Mechanisms of Glutathione Uptake in the Rodent Lens: A Novel Role for Vitreous Humor in Lens Glutathione Homeostasis. Invest Ophthalmol Vis Sci 2017; 57:3914-25. [PMID: 27472077 PMCID: PMC4998144 DOI: 10.1167/iovs.16-19592] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose Lens glutathione synthesis knockout (LEGSKO) mouse lenses lack de novo glutathione (GSH) synthesis but still maintain >1 mM GSH. We sought to determine the source of this residual GSH and the mechanism by which it accumulates in the lens. Methods Levels of GSH, glutathione disulfide (GSSG), and GSH-related compounds were measured in vitro and in vivo using isotope standards and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Results Wild-type (WT) lenses could accumulate GSH from γ-glutamylcysteine and glycine or from intact GSH, but LEGSKO lenses could only accumulate GSH from intact GSH, indicating that LEGSKO lens GSH content is not due to synthesis by a salvage pathway. Uptake of GSH in cultured lenses occurred at the same rate for LEGSKO and WT lenses, could not be inhibited, and occurred primarily through cortical fiber cells. In contrast, uptake of GSH from aqueous humor could be competitively inhibited and showed an enhanced Km in LEGSKO lenses. Mouse vitreous had >1 mM GSH, whereas aqueous had <20 μM GSH. Testing physiologically relevant GSH concentrations for uptake in vivo, we found that both LEGSKO and WT lenses could obtain GSH from the vitreous but not from the aqueous. Vitreous rapidly accumulated GSH from the circulation, and depletion of circulating GSH reduced vitreous but not aqueous GSH. Conclusions The above data provide, for the first time, evidence for the existence of dual mechanisms of GSH uptake into the lens, one mechanism being a passive, high-flux transport through the vitreous exposed side of the lens versus an active, carrier-mediated uptake mechanism at the anterior of the lens.
Collapse
Affiliation(s)
- Jeremy A Whitson
- Department of Pathology Case Western Reserve University, Cleveland, Ohio, United States
| | - David R Sell
- Department of Pathology Case Western Reserve University, Cleveland, Ohio, United States
| | - Michael C Goodman
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States
| | - Vincent M Monnier
- Department of Pathology Case Western Reserve University, Cleveland, Ohio, United States 3Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, United States
| | - Xingjun Fan
- Department of Pathology Case Western Reserve University, Cleveland, Ohio, United States
| |
Collapse
|
14
|
Slavi N, Wang Z, Harvey L, Schey KL, Srinivas M. Identification and Functional Assessment of Age-Dependent Truncations to Cx46 and Cx50 in the Human Lens. Invest Ophthalmol Vis Sci 2016; 57:5714-5722. [PMID: 27787559 PMCID: PMC5089213 DOI: 10.1167/iovs.16-19698] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/21/2016] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Many proteins in the lens undergo extensive posttranslational modifications (PTMs) with age, leading to alterations in their function. The extent to which lens gap junction proteins, Cx46 and Cx50, accumulate PTMs with aging is not known. In this study, we identified truncations in Cx46 and Cx50 in the human lens using mass spectrometry. We also examined the effect of truncations on channel function using electrophysiological measurements. METHODS Human lenses were dissected into cortex, outer nucleus, and nucleus regions, and fiber cell membranes were subjected to trypsin digestion. Tryptic peptides were analyzed by liquid chromatography (LC)-electrospray tandem mass spectrometry (ESI/MS/MS). Effects of truncations on channel conductance, permeability, and gating were assessed in transfected cells. RESULTS Cleavage sites were identified in the C-terminus, the cytoplasmic loop, and the N-terminus of Cx46 and Cx50. Levels of C-terminal truncations, which were found at residues 238 to 251 in Cx46 and at residues 238 to 253 and 274 to 284 in Cx50, were similar in different lens regions. In contrast, levels of truncations in cytoplasmic loop and N-terminal domains of Cx46 and Cx50 increased dramatically from outer cortex to nucleus. Most of the C-terminally truncated proteins were functional, whereas truncations in the cytoplasmic loop did not result in the formation of functional channels. CONCLUSIONS Accumulation of cytoplasmic loop and N-terminal truncations in the core might lead to decreases in coupling with age. This reduction is expected to lead to an increase in intracellular calcium and a decrease in levels of glutathione in the nucleus. These changes may ultimately lead to age-related nuclear cataracts.
Collapse
Affiliation(s)
- Nefeli Slavi
- Department of Biological and Vision Sciences and the Graduate Center for Vision Research, SUNY College of Optometry, New York, New York, United States
| | - Zhen Wang
- Department of Biochemistry and Mass Spectrometry Research Center Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Lucas Harvey
- Department of Biological and Vision Sciences and the Graduate Center for Vision Research, SUNY College of Optometry, New York, New York, United States
| | - Kevin L. Schey
- Department of Biochemistry and Mass Spectrometry Research Center Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Miduturu Srinivas
- Department of Biological and Vision Sciences and the Graduate Center for Vision Research, SUNY College of Optometry, New York, New York, United States
| |
Collapse
|
15
|
Gao J, Sun X, White TW, Delamere NA, Mathias RT. Feedback Regulation of Intracellular Hydrostatic Pressure in Surface Cells of the Lens. Biophys J 2016; 109:1830-9. [PMID: 26536260 DOI: 10.1016/j.bpj.2015.09.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/08/2015] [Accepted: 09/16/2015] [Indexed: 10/22/2022] Open
Abstract
In wild-type lenses from various species, an intracellular hydrostatic pressure gradient goes from ∼340 mmHg in central fiber cells to 0 mmHg in surface cells. This gradient drives a center-to-surface flow of intracellular fluid. In lenses in which gap-junction coupling is increased, the central pressure is lower, whereas if gap-junction coupling is reduced, the central pressure is higher but surface pressure is always zero. Recently, we found that surface cell pressure was elevated in PTEN null lenses. This suggested disruption of a feedback control system that normally maintained zero surface cell pressure. Our purpose in this study was to investigate and characterize this feedback control system. We measured intracellular hydrostatic pressures in mouse lenses using a microelectrode/manometer-based system. We found that all feedback went through transport by the Na/K ATPase, which adjusted surface cell osmolarity such that pressure was maintained at zero. We traced the regulation of Na/K ATPase activity back to either TRPV4, which sensed positive pressure and stimulated activity, or TRPV1, which sensed negative pressure and inhibited activity. The inhibitory effect of TRPV1 on Na/K pumps was shown to signal through activation of the PI3K/AKT axis. The stimulatory effect of TRPV4 was shown in previous studies to go through a different signal transduction path. Thus, there is a local two-legged feedback control system for pressure in lens surface cells. The surface pressure provides a pedestal on which the pressure gradient sits, so surface pressure determines the absolute value of pressure at each radial location. We speculate that the absolute value of intracellular pressure may set the radial gradient in the refractive index, which is essential for visual acuity.
Collapse
Affiliation(s)
- Junyuan Gao
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York
| | - Xiurong Sun
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York
| | - Nicholas A Delamere
- Department of Physiology and Biophysics, University of Arizona, Tucson, Arizona
| | - Richard T Mathias
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York.
| |
Collapse
|
16
|
Fan X, Monnier VM, Whitson J. Lens glutathione homeostasis: Discrepancies and gaps in knowledge standing in the way of novel therapeutic approaches. Exp Eye Res 2016; 156:103-111. [PMID: 27373973 DOI: 10.1016/j.exer.2016.06.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 03/10/2016] [Accepted: 06/25/2016] [Indexed: 01/18/2023]
Abstract
Cataract is the major cause of blindness worldwide. The WHO has estimated around 20 million people have bilateral blindness from cataract, and that number is expected to reach 50 million in 2050. The cataract surgery is currently the main treatment approach, though often associated with complications, such as Posterior Capsule Opacification (PCO)-also known as secondary cataract. The lens is an avascular ocular structure equipped with an unusually high level of glutathione (GSH), which plays a vital role in maintaining lens transparency by regulating lenticular redox state. The lens epithelium and outer cortex are thought to be responsible for providing the majority of lens GSH via GSH de novo synthesis, assisted by a continuous supply of constituent amino acids from the aqueous humor, as well as extracellular GSH recycling from the gamma-glutamyl cycle. However, when de novo synthesis is impaired, in the presence of low GSH levels, as in the aging human lens, compensatory mechanisms exist, suggesting that the lens is able to uptake GSH from the surrounding ocular tissues. However, these uptake mechanisms, and the GSH source and its origin, are largely unknown. The lens nucleus does not have the ability to synthesize its own GSH and fully relies on transport from the outer cortex by yet unknown mechanisms. Understanding how aging reduces GSH levels, particularly in the lens nucleus, how it is associated with age-related nuclear cataract (ARNC), and how the lens compensates for GSH loss via external uptake should be a major research priority. The intent of this review, which is dedicated to the memory of David C. Beebe, is to summarize our current understanding of lens GSH homeostasis and highlight discrepancies and gaps in knowledge that stand in the way of pharmacologically minimizing the impact of declining GSH content in the prevention of age-related cataract.
Collapse
Affiliation(s)
- Xingjun Fan
- Department of Pathology, Case Western Reserve University, USA.
| | - Vincent M Monnier
- Department of Pathology, Case Western Reserve University, USA; Department of Biochemistry, Case Western Reserve University, USA
| | - Jeremy Whitson
- Department of Pathology, Case Western Reserve University, USA
| |
Collapse
|
17
|
Lim JC, Umapathy A, Grey AC, Vaghefi E, Donaldson PJ. Novel roles for the lens in preserving overall ocular health. Exp Eye Res 2016; 156:117-123. [PMID: 27282996 DOI: 10.1016/j.exer.2016.05.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 05/12/2016] [Accepted: 05/29/2016] [Indexed: 12/11/2022]
Abstract
Outside the traditional roles of the lens as an important refractive element and a UV filter, it was David Beebe's group that first demonstrated that the lens acts an oxygen sink that protects the tissues of the anterior segment of the eye from oxygen or oxygen metabolites. In this review, we follow on from this work, and present new evidence from our laboratory to demonstrate that the lens serves as a reservoir for the release of the antioxidant glutathione (GSH) into the aqueous humor to provide a source of GSH and/or its precursor amino acids to nearby tissues that interface with the aqueous humor, or to remove toxic metabolites from the eye via the aqueous outflow pathway. In addition to GSH release, our laboratory and others have shown that ATP is released from the lens under hyposmotic conditions to activate purinergic signalling pathways in an autocrine manner to alter lens function. In this review, we raise the idea that ATP and/or its subsequent degradation product adenosine may exert a paracrine function and influence purinergic signalling systems in other tissues to alter aqueous humor outflow. These new secondary roles indicate that the lens is not just a passive optical element, but a highly dynamic and active tissue that interacts with its neighbouring tissues, through modifying the environments in which these tissues function. We believe that the lens actively contributes to the ocular environment and as a consequence, removal of the lens would alter the functionality of neighbouring tissues. We speculate that a long term effect of lens removal may be to inadvertently increase the exposure of anterior tissues of the eye to oxidative stress due to elevated oxygen levels and a reduction in the availability of GSH and purinergic signalling molecules in the aqueous humor. Since cataract surgery is now being performed on younger patients due to our increasing diabetic population, over time, we predict these changes may increase the susceptibility of these tissues to oxidative stress and the incidence of subsequent ocular pathologies. If our view of the lens is correct, the actual loss of the biological lens may have longer term consequences for overall ocular health than currently appreciated.
Collapse
Affiliation(s)
- Julie C Lim
- Department of Physiology, University of Auckland, Auckland, New Zealand; School of Medical Sciences, University of Auckland, New Zealand; New Zealand National Eye Centre, University of Auckland, New Zealand.
| | - Ankita Umapathy
- Department of Physiology, University of Auckland, Auckland, New Zealand; School of Medical Sciences, University of Auckland, New Zealand; New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Angus C Grey
- Department of Physiology, University of Auckland, Auckland, New Zealand; School of Medical Sciences, University of Auckland, New Zealand; New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Ehsan Vaghefi
- School of Optometry and Vision Science, University of Auckland, New Zealand; New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Paul J Donaldson
- Department of Physiology, University of Auckland, Auckland, New Zealand; School of Medical Sciences, University of Auckland, New Zealand; New Zealand National Eye Centre, University of Auckland, New Zealand
| |
Collapse
|
18
|
The aquaporin zero puzzle. Biophys J 2015; 107:10-5. [PMID: 24988336 DOI: 10.1016/j.bpj.2014.05.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/05/2014] [Accepted: 05/20/2014] [Indexed: 11/20/2022] Open
|
19
|
Langford MP, Redens TB, Liang C, Kavanaugh AS, Texada DE. EAAT and Xc⁻ Exchanger Inhibition Depletes Glutathione in the Transformed Human Lens Epithelial Cell Line SRA 01/04. Curr Eye Res 2015; 41:357-66. [PMID: 25897760 DOI: 10.3109/02713683.2015.1017651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
PURPOSE Maintaining the high glutathione (GSH; tripeptide of glutamate, cysteine and glycine) levels in the lens cortex promotes lens health. The role of glutamate/aspartate (Glu/Asp) transporters and the cystine (Cys)/Glu exchanger (Xc(-) exchanger) in maintaining GSH in transformed human lens epithelial cells (SRA 01/04) was investigated. METHODS Detection and differentiation of excitatory amino acid transporters (EAAT1-5) and the Xc(-) exchanger was performed by the uptake of radiolabeled l-Glu, d-Asp and l-Cys in the presence and absence of Na(+), substrate-specific inhibition studies and Western-blot analysis. Reductions in GSH levels post-inhibition of Xc(-) exchanger and EAAT activities by substrate inhibitors demonstrated the roles of EAAT and Xc(-) exchanger in maintaining GSH. RESULTS Glu and d-Asp uptake in HLEC was Na(+)-dependent. Strong inhibition by substrate-specific Glu/Asp uptake inhibitors and weak inhibition by kainic acid (KA) was consistent with Na(+)-dependent EAAT1/3/4/5 activity and weak EAAT2 activity, respectively. Na(+)-independency and Glu inhibition of Cys uptake were consistent with Xc(-) exchanger activity, but inhibition of Na(+)-dependent Cys uptake by N-acetylcysteine suggests Cys uptake by EAAT3. EAAT1-5 and xCT (Xc(-) exchanger light chain) immunoreactive peptides were detected by Western-blot analysis of HLEC lysates. EAAT and Xc(-) exchanger inhibition by substrate antagonists depleted GSH concentrations by 15-28% (p's ≤ 0.02), while GSH synthesis inhibition by buthionine sulfoximine depleted GSH by 33% (p = 0.008). CONCLUSION Inhibition of Glu and Cys uptake by EAAT and Xc(-) exchanger antagonists depletes GSH in human lens epithelial cells. These in vitro results support pivotal roles for EAAT and Xc(-) exchanger activities in maintaining GSH and protection against oxidative stress in cortical lens epithelium.
Collapse
Affiliation(s)
- Marlyn P Langford
- a Department of Ophthalmology , Louisiana State University Health Sciences Center , Shreveport , LA , USA
| | - Thomas B Redens
- a Department of Ophthalmology , Louisiana State University Health Sciences Center , Shreveport , LA , USA
| | - Chanping Liang
- a Department of Ophthalmology , Louisiana State University Health Sciences Center , Shreveport , LA , USA
| | - A Scott Kavanaugh
- a Department of Ophthalmology , Louisiana State University Health Sciences Center , Shreveport , LA , USA
| | - Donald E Texada
- a Department of Ophthalmology , Louisiana State University Health Sciences Center , Shreveport , LA , USA
| |
Collapse
|
20
|
Tsentalovich YP, Verkhovod TD, Yanshole VV, Kiryutin AS, Yanshole LV, Fursova AZ, Stepakov DA, Novoselov VP, Sagdeev RZ. Metabolomic composition of normal aged and cataractous human lenses. Exp Eye Res 2015; 134:15-23. [PMID: 25773987 DOI: 10.1016/j.exer.2015.03.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/06/2015] [Accepted: 03/11/2015] [Indexed: 10/23/2022]
Abstract
Quantitative metabolomic profiles of normal and cataractous human lenses were obtained with the combined use of high-frequency nuclear magnetic resonance (NMR) and high-performance liquid chromatography with high-resolution mass-spectrometric detection (LC-MS) methods. The concentration of more than fifty metabolites in the lens cortex and nucleus has been determined. For the majority of metabolites, their concentrations in the lens cortex and nucleus are similar, which confirms low metabolic activity in the lens core. The difference between the metabolite levels in the cortex and nucleus of the normal lens is observed for antioxidants and UV filters, which demonstrates the activity of redox processes in the lens. A huge difference is found between the metabolomic compositions of normal and age-matched cataractous lenses: the concentrations of almost all metabolites in the normal lens are higher than in the cataractous one. The most pronounced difference is observed for compounds playing a key role in the lens cell protection and metabolic activity, including antioxidants, UV filters, and osmolytes. The results obtained imply that the development of the age-related cataracts might originate from the metabolic dysfunction of the lens epithelial cells.
Collapse
Affiliation(s)
- Yuri P Tsentalovich
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia.
| | - Timofey D Verkhovod
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090, Russia
| | - Vadim V Yanshole
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia
| | - Alexey S Kiryutin
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090, Russia
| | - Lyudmila V Yanshole
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia
| | - Anjella Zh Fursova
- Novosibirsk State Regional Clinical Hospital, Nemirovicha-Danchenko 130, Novosibirsk 630087, Russia
| | - Denis A Stepakov
- Novosibirsk Regional Clinical Bureau of Forensic Medical Examination, Nemirovicha-Danchenko 134, Novosibirsk 630087, Russia
| | - Vladimir P Novoselov
- Novosibirsk Regional Clinical Bureau of Forensic Medical Examination, Nemirovicha-Danchenko 134, Novosibirsk 630087, Russia
| | - Renad Z Sagdeev
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia
| |
Collapse
|
21
|
Langford MP, Redens TB, Texada DE. Excitatory Amino Acid Transporters, Xc− Antiporter, γ-Glutamyl Transpeptidase, Glutamine Synthetase, and Glutathione in Human Corneal Epithelial Cells. OXIDATIVE STRESS IN APPLIED BASIC RESEARCH AND CLINICAL PRACTICE 2015. [DOI: 10.1007/978-1-4939-1935-2_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
22
|
Umapathy A, Donaldson P, Lim J. Antioxidant delivery pathways in the anterior eye. BIOMED RESEARCH INTERNATIONAL 2013; 2013:207250. [PMID: 24187660 PMCID: PMC3804153 DOI: 10.1155/2013/207250] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 08/08/2013] [Indexed: 02/04/2023]
Abstract
Tissues in the anterior segment of the eye are particular vulnerable to oxidative stress. To minimise oxidative stress, ocular tissues utilise a range of antioxidant defence systems which include nonenzymatic and enzymatic antioxidants in combination with repair and chaperone systems. However, as we age our antioxidant defence systems are overwhelmed resulting in increased oxidative stress and damage to tissues of the eye and the onset of various ocular pathologies such as corneal opacities, lens cataracts, and glaucoma. While it is well established that nonenzymatic antioxidants such as ascorbic acid and glutathione are important in protecting ocular tissues from oxidative stress, less is known about the delivery mechanisms used to accumulate these endogenous antioxidants in the different tissues of the eye. This review aims to summarise what is currently known about the antioxidant transport pathways in the anterior eye and how a deeper understanding of these transport systems with respect to ocular physiology could be used to increase antioxidant levels and delay the onset of eye diseases.
Collapse
Affiliation(s)
- Ankita Umapathy
- Department of Optometry and Vision Science, University of Auckland, Auckland 1023, New Zealand
- New Zealand National Eye Centre, University of Auckland, Auckland 1023, New Zealand
| | - Paul Donaldson
- New Zealand National Eye Centre, University of Auckland, Auckland 1023, New Zealand
- School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand
| | - Julie Lim
- Department of Optometry and Vision Science, University of Auckland, Auckland 1023, New Zealand
- New Zealand National Eye Centre, University of Auckland, Auckland 1023, New Zealand
| |
Collapse
|
23
|
Characterization of Glutathione Uptake, Synthesis, and Efflux Pathways in the Epithelium and Endothelium of the Rat Cornea. Cornea 2012; 31:1304-12. [DOI: 10.1097/ico.0b013e31823f76bd] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
24
|
Chen CH, Lin WC, Kuo CN, Lu FJ. Role of redox signaling regulation in propyl gallate-induced apoptosis of human leukemia cells. Food Chem Toxicol 2011; 49:494-501. [DOI: 10.1016/j.fct.2010.11.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 10/08/2010] [Accepted: 11/20/2010] [Indexed: 12/22/2022]
|