1
|
Liu X, Yu Y, Garcia LA, Au ML, Tran M, Zhang J, Lou A, Liu Y, Wu H. A grape-supplemented diet prevented ultraviolet (UV) radiation-induced cataract by regulating Nrf2 and XIAP pathways. J Nutr Biochem 2024; 129:109636. [PMID: 38561079 PMCID: PMC11107911 DOI: 10.1016/j.jnutbio.2024.109636] [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: 10/13/2023] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/04/2024]
Abstract
The purpose of this study is to investigate if grape consumption, in the form of grape powder (GP), could protect against ultraviolet (UV)-induced cataract. Mice were fed with the regular diet, sugar placebo diet, or a grape diet (regular diet supplemented with 5%, 10%, and 15% GP) for 3 months. The mice were then exposed to UV radiation to induce cataract. The results showed that the GP diet dose-dependently inhibited UV-induced cataract and preserved glutathione pools. Interestingly, UV-induced Nrf2 activation was abolished in the groups on the GP diet, suggesting GP consumption may improve redox homeostasis in the lens, making Nrf2 activation unnecessary. For molecular target prediction, a total of 471 proteins regulated by GP were identified using Agilent Literature Search (ALS) software. Among these targets, the X-linked inhibitor of apoptosis (XIAP) was correlated with all of the main active ingredients of GP, including resveratrol, catechin, quercetin, and anthocyanins. Our data confirmed that GP prevented UV-induced suppression of XIAP, indicating that XIAP might be one of the critical molecular targets of GP. In conclusion, this study demonstrated that GP protected the lens from UV-induced cataract development in mice. The protective effects of GP may be attributed to its ability to improve redox homeostasis and activate the XIAP-mediated antiapoptotic pathway.
Collapse
Affiliation(s)
- Xiaobin Liu
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Yu Yu
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Luís Aguilera Garcia
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - My-Lien Au
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Myhoa Tran
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Jinmin Zhang
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Alexander Lou
- The Village School, Houston, Texas, USA; Loyola University Chicago, Chicago, Illinois, USA
| | - Yang Liu
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Hongli Wu
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, USA.
| |
Collapse
|
2
|
Chen X, Tzekov R, Su M, Zhu Y, Han A, Li W. Hydrogen peroxide-induced oxidative damage and protective role of peroxiredoxin 6 protein via EGFR/ERK signaling pathway in RPE cells. Front Aging Neurosci 2023; 15:1169211. [PMID: 37529008 PMCID: PMC10388243 DOI: 10.3389/fnagi.2023.1169211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 06/26/2023] [Indexed: 08/03/2023] Open
Abstract
Introduction Damage to retinal pigment epithelium (RPE) cells caused by oxidative stress is closely related to the pathogenesis of several blinding retinal diseases, such as age-related macular degeneration (AMD), retinitis pigmentosa, and other inherited retinal degenerative conditions. However, the mechanisms of this process are poorly understood. Hence, the goal of this study was to investigate hydrogen peroxide (H2O2)-induced oxidative damage and protective role of peroxiredoxin 6 (PRDX6) protein via EGFR/ERK signaling pathway in RPE cells. Methods Cells from a human RPE cell line (ARPE-19 cells) were treated with H2O2, and then cell viability was assessed using the methyl thiazolyl tetrazolium assay. Cell death and reactive oxygen species (ROS) were detected by flow cytometry. The levels of PRDX6, epidermal growth factor receptor (EGFR), P38 mitogen-activated protein kinase (P38MAPK), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) were detected by Western blot assay. PRDX6 and EGFR were also detected via immunofluorescence staining. Results Our results show that H2O2 inhibited cell viability, induced cell death, and increased ROS levels in ARPE-19 cells. It was also found that H2O2 decreased the levels of PRDX6, EGFR, and phosphorylated ERK but increased the levels of phosphorylated P38MAPK and JNK. PRDX6 overexpression was found to attenuate H2O2-induced inhibition of cell viability and increased cell death and ROS production in ARPE-19 cells. PRDX6 overexpression also increased the expression of EGFR and alleviated the H2O2-induced decrease in EGFR and phosphorylated ERK. Moreover, inhibition of epidermal growth factor-induced EGFR and ERK signaling in oxidative stress was partially blocked by PRDX6 overexpression. Discussion Our findings indicate that PRDX6 overexpression protects RPE cells from oxidative stress damage caused by decreasing ROS production and partially blocking the inhibition of the EGFR/ERK signaling pathway induced by oxidative stress. Therefore, PRDX6 shows promise as a therapeutic target for the prevention of RPE cell damage caused by oxidative stress associated with retinal diseases.
Collapse
Affiliation(s)
- Xiaodong Chen
- Department of Ophthalmology, Xi’an No. 1 Hospital, Shaanxi Institute of Ophthalmology, First Affiliated Hospital of Northwest University, Northwest University, Xi’an, Shaanxi, China
- Xiamen Eye Center of Xiamen University, Xiamen University, Xiamen, Fujian, China
| | - Radouil Tzekov
- Department of Ophthalmology, University of South Florida, Tampa, FL, United States
| | - Mingyang Su
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan, Xiamen, China
| | - Yusheng Zhu
- Department of Ophthalmology, Xi’an No. 1 Hospital, Shaanxi Institute of Ophthalmology, First Affiliated Hospital of Northwest University, Northwest University, Xi’an, Shaanxi, China
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan, Xiamen, China
| | - Wensheng Li
- Shanghai Aier Eye Hospital, Shanghai, China
- Shanghai Aier Eye Institute, Shanghai, China
- Aier School of Ophthalmology, Central South University, Changsha, Hunan, China
| |
Collapse
|
3
|
Chhunchha B, Kubo E, Krueger RR, Singh DP. Hydralazine Revives Cellular and Ocular Lens Health-Span by Ameliorating the Aging and Oxidative-Dependent Loss of the Nrf2-Activated Cellular Stress Response. Antioxidants (Basel) 2023; 12:140. [PMID: 36671002 PMCID: PMC9854670 DOI: 10.3390/antiox12010140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/10/2023] Open
Abstract
A major hallmark of aging-associated diseases is the inability to evoke cellular defense responses. Transcriptional protein Nrf2 (nuclear factor erythroid-derived 2-related factor) plays a pivotal role in the oxidative stress response, cellular homeostasis, and health span. Nrf2's activation has been identified as a therapeutic target to restore antioxidant defense in aging. Here, we demonstrated that FDA-approved drug, hydralazine (Hyd), was a reactivator of the Nrf2/ARE (antioxidant response element) pathway in various ages and types of mouse (m) or human (h) lens epithelial cells (LECs) and mice lenses in-vitro/in-vivo. This led to Hyd-driven abatement of carbonyls, reduced reactive oxygen species (ROS), and reduced 4-HNE/MDA-adducts with cytoprotection, and extended lens healthspan by delaying/preventing lens opacity against aging/oxidative stress. We elucidated that Hyd activated the protective signaling by inducing Nrf2 to traverse from the cytoplasm to the nucleus and potentiated the ARE response by direct interaction of Nrf2 and ARE sequences of the promoter. Loss-of-function study and cotreatment of Hyd and antioxidant, N-acetyl cysteine (NAC) or Peroxiredoxin (Prdx)6, specified that Nrf2/ARE-driven increase in the promoter activity was Hyd-dependent. Our study provides proof-of concept evidence and, thereby, paves the way to repurposing Hyd as a therapeutic agent to delay/prevent aging and oxidative-related disorders.
Collapse
Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Kanazawa 9200293, Japan
| | - Ronald R. Krueger
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| |
Collapse
|
4
|
Chhunchha B, Kubo E, Singh DP. Obligatory Role of AMPK Activation and Antioxidant Defense Pathway in the Regulatory Effects of Metformin on Cellular Protection and Prevention of Lens Opacity. Cells 2022; 11:3021. [PMID: 36230981 PMCID: PMC9563310 DOI: 10.3390/cells11193021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/15/2022] [Accepted: 09/21/2022] [Indexed: 11/18/2022] Open
Abstract
Increasing levels of oxidative-stress due to deterioration of the Nrf2 (NFE2-related factor)/ARE (antioxidant response element) pathway is found to be a primary cause of aging pathobiology. Metformin having anti-aging effects can delay/halt aging-related diseases. Herein, using lens epithelial cell lines (LECs) of human (h) or mouse (m) and aging h/m primary LECs along with lenses as model systems, we demonstrated that Metformin could correct deteriorated Bmal1/Nrf2/ARE pathway by reviving AMPK-activation, and transcriptional activities of Bmal1/Nrf2, resulting in increased antioxidants enzymatic activity and expression of Phase II enzymes. This ensued reactive oxygen species (ROS) mitigation with cytoprotection and prevention of lens opacity in response to aging/oxidative stress. It was intriguing to observe that Metformin internalized lens/LECs and upregulated OCTs (Organic Cation Transporters). Mechanistically, we found that Metformin evoked AMPK activation-dependent increase of Bmal1, Nrf2, and antioxidants transcription by promoting direct E-Box and ARE binding of Bmal1 and Nrf2 to the promoters. Loss-of-function and disruption of E-Box/ARE identified that Metformin acted by increasing Bmal1/Nrf2-mediated antioxidant expression. Data showed that AMPK-activation was a requisite for Bmal1/Nrf2-antioxidants-mediated defense, as pharmacologically inactivating AMPK impeded the Metformin's effect. Collectively, the results for the first-time shed light on the hitherto incompletely uncovered crosstalk between the AMPK and Bmal1/Nrf2/antioxidants mediated by Metformin for blunting oxidative/aging-linked pathobiology.
Collapse
Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 9200293, Japan
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| |
Collapse
|
5
|
Switching of Redox Signaling by Prdx6 Expression Decides Cellular Fate by Hormetic Phenomena Involving Nrf2 and Reactive Oxygen Species. Cells 2022; 11:cells11081266. [PMID: 35455944 PMCID: PMC9028283 DOI: 10.3390/cells11081266] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 12/15/2022] Open
Abstract
Changes in intracellular reactive oxygen species (ROS) levels due to remodeling of antioxidant defense can affect the status of biological homeostasis in aging/oxidative stress. Peroxiredoxin 6 (Prdx6), an antioxidant gene downstream target for the Nrf2 pathway, plays a role in regulating ROS homeostasis. Using aging human (h) lens epithelial cells (LECs) or Prdx6-deficient (Prdx6-/-) mouse (m) LECs, here we showed that dichlorofluorescein (DCF) oxidation or H2O2 were strictly controlled by Prdx6. We observed that a moderate degree of oxidative stress augmented Nrf2-mediated Prdx6 expression, while higher doses of H2O2 (≥100 µM) caused a dramatic loss of Prdx6 expression, resulting in increased DCF oxidation and H2O2 amplification and cell death. Mechanistically, at increased oxidative stress, Nrf2 upregulated transcriptional factor Klf9, and that Klf9 bound to the promoter and repressed the Prdx6 gene. Similarly, cells overexpressing Klf9 displayed Klf9-dependent Prdx6 suppression and DCF oxidation with H2O2 amplification, while ShKlf9 reversed the process. Our data revealed that H2O2 and DCF oxidation levels play a hormetical role, and the Nrf2-Klf9-Prdx6 pathway is pivotal for the phenomena under the conditions of oxidative load/aging. On the whole, the results demonstrate that oxidative hormetical response is essentially based on levels of oxidative triggering and the status of Klf9-Prdx6 pathway activation; thus, Klf9 can be considered as a therapeutic target for hormetic shifting of cellular defense to improve protective resilience to oxidative stress.
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Wu L, Lu P, Guo X, Song K, Lyu Y, Bothwell J, Wu J, Hawkins O, Clarke SL, Lucas EA, Smith BJ, Chowanadisai W, Hartson SD, Ritchey JW, Wang W, Medeiros DM, Li S, Lin D. β-carotene oxygenase 2 deficiency-triggered mitochondrial oxidative stress promotes low-grade inflammation and metabolic dysfunction. Free Radic Biol Med 2021; 164:271-284. [PMID: 33453359 PMCID: PMC7946548 DOI: 10.1016/j.freeradbiomed.2021.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/30/2020] [Accepted: 01/03/2021] [Indexed: 02/06/2023]
Abstract
Low-grade inflammation is a critical pathological factor contributing to the development of metabolic disorders. β-carotene oxygenase 2 (BCO2) was initially identified as an enzyme catalyzing carotenoids in the inner mitochondrial membrane. Mutations in BCO2 are associated with inflammation and metabolic disorders in humans, yet the underlying mechanisms remain unknown. Here, we used loss-of-function approaches in mice and cell culture models to investigate the role of BCO2 in inflammation and metabolic dysfunction. We demonstrated decreases in BCO2 mRNA and protein levels and suppression of mitochondrial respiratory complex I proteins and mitochondrial superoxide dismutase levels in the liver of type 2 diabetic human subjects. Deficiency of BCO2 caused disruption of assembly of the mitochondrial respiratory supercomplexes, such as supercomplex III2+IV in mice, and overproduction of superoxide radicals in primary mouse embryonic fibroblasts. Further, deficiency of BCO2 increased protein carbonylation and populations of natural killer cells and M1 macrophages, and decreased populations of T cells, including CD4+ and/or CD8+ in the bone marrow and white adipose tissues. Elevation of plasma inflammatory cytokines and adipose tissue hypertrophy and inflammation were also characterized in BCO2 deficient mice. Moreover, BCO2 deficient mice were more susceptible to high-fat diet-induced obesity and hyperglycemia. Double knockout of BCO2 and leptin receptor genes caused a significantly greater elevation of the fasting blood glucose level in mice at 4 weeks of age, compared to the age- and sex-matched leptin receptor knockout. Finally, administration of Mito-TEMPO, a mitochondrial specific antioxidant attenuated systemic low-grade inflammation induced by BCO2 deficiency. Collectively, these findings suggest that BCO2 is essential for mitochondrial respiration and metabolic homeostasis in mammals. Loss or decreased expression of BCO2 leads to mitochondrial oxidative stress, low-grade inflammation, and the subsequent development of metabolic disorders.
Collapse
Affiliation(s)
- Lei Wu
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Peiran Lu
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Xin Guo
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Kun Song
- Department of Microbiology and Immunology, Tulane University, New Orleans, LA, 70112, USA
| | - Yi Lyu
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - James Bothwell
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jinglong Wu
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Olivia Hawkins
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Stephen L Clarke
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Edralin A Lucas
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Brenda J Smith
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Winyoo Chowanadisai
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Steve D Hartson
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Jerry W Ritchey
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Weiqun Wang
- Department of Food, Nutrition, Dietetics, and Health, Kansas State University, Manhattan, KS, 66506, USA
| | - Denis M Medeiros
- Department of Molecular Biology and Biochemistry, University of Missouri-Kansas City, Kansas City, MO, 64110, USA
| | - Shitao Li
- Department of Microbiology and Immunology, Tulane University, New Orleans, LA, 70112, USA
| | - Dingbo Lin
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, 74078, USA.
| |
Collapse
|
8
|
Álvarez-Barrios A, Álvarez L, García M, Artime E, Pereiro R, González-Iglesias H. Antioxidant Defenses in the Human Eye: A Focus on Metallothioneins. Antioxidants (Basel) 2021; 10:89. [PMID: 33440661 PMCID: PMC7826537 DOI: 10.3390/antiox10010089] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 12/12/2022] Open
Abstract
The human eye, the highly specialized organ of vision, is greatly influenced by oxidants of endogenous and exogenous origin. Oxidative stress affects all structures of the human eye with special emphasis on the ocular surface, the lens, the retina and its retinal pigment epithelium, which are considered natural barriers of antioxidant protection, contributing to the onset and/or progression of eye diseases. These ocular structures contain a complex antioxidant defense system slightly different along the eye depending on cell tissue. In addition to widely studied enzymatic antioxidants, including superoxide dismutase, glutathione peroxidase, catalase, peroxiredoxins and selenoproteins, inter alia, metallothioneins (MTs) are considered antioxidant proteins of growing interest with further cell-mediated functions. This family of cysteine rich and low molecular mass proteins captures and neutralizes free radicals in a redox-dependent mechanism involving zinc binding and release. The state of the art of MTs, including the isoforms classification, the main functions described to date, the Zn-MT redox cycle as antioxidant defense system, and the antioxidant activity of Zn-MTs in the ocular surface, lens, retina and its retinal pigment epithelium, dependent on the number of occupied zinc-binding sites, will be comprehensively reviewed.
Collapse
Affiliation(s)
- Ana Álvarez-Barrios
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Lydia Álvarez
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Montserrat García
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
| | - Enol Artime
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Rosario Pereiro
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
| |
Collapse
|
9
|
Yu H, Yu Y, Zhao Z, Cui L, Hou J, Shi H. Prdx6 is required to protect human corneal epithelial cells against ultraviolet B injury. Eur J Ophthalmol 2019; 31:367-378. [PMID: 31875691 DOI: 10.1177/1120672119896426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The protective role of Prdx6 on rat corneal tissue against ultraviolet B injury in vivo has been confirmed previously. We further investigated the function and molecular mechanism of Prdx6 in human corneal epithelial cells under ultraviolet B radiation. METHODS The experimental groups were designed as follows: (1) Prdx6 RNAi, (2) Prdx6 RNAi + ultraviolet B radiation, (3) normal human corneal epithelial cells, (4) normal human corneal epithelial cells + ultraviolet B radiation, (5) wild-type Prdx6 overexpression, (6) wild-type Prdx6 overexpression + ultraviolet B radiation, (7) mutant-type Prdx6 overexpression, and (8) mutant-type Prdx6 overexpression + ultraviolet B radiation. The cell survival rate was detected by a Thiazolyl Blue Tetrazolium Bromide assay. Apoptosis, reactive oxygen species, and malondialdehyde were detected with a commercial kit. Gene expression was detected by real-time polymerase chain reaction. RESULTS We found the following results. (1) Compared to normal cells, the survival rates were 32%, 87%, and 58% under ultraviolet B radiation in the Prdx6 interference, wild-type overexpression, and mutant-type overexpression groups, respectively. The survival rates were decreased to 50% at 24 h and 31% at 48 h when the phospholipase A2 activity of Prdx6 was inhibited after ultraviolet B radiation. (2) Apoptosis, reactive oxygen species content, and malondialdehyde levels were increased when Prdx6 was downregulated. This phenomenon became more severe under ultraviolet B radiation. (3) The expression levels of apoptosis-related and antioxidant genes all changed along with the changes in expression of Prdx6. CONCLUSION (1) Both peroxidase and phospholipase A2 activities of Prdx6 are crucial for its protective role in corneal tissue. (2) Downregulated expression of Prdx6 resulted in high endoplasmic reticulum stress. (3) Apoptosis in human corneal epithelial cells with downregulated Prdx6 coupled with ultraviolet B radiation was related to the pathways of DNA damage and the death receptor. (4) Low levels of antioxidants are sufficient for maintaining homeostasis in human corneal epithelial cells without external stimuli. Under the condition that Prdx6 was downregulated, human corneal epithelial cells were more sensitive to ultraviolet B radiation.
Collapse
Affiliation(s)
- Huajun Yu
- Department of Ophthalmology, Yantai Yuhuangding Hospital, Yantai, P.R. China
| | - Yonghong Yu
- Department of Ophthalmology, Yantai Yuhuangding Hospital, Yantai, P.R. China
| | - Zhenjun Zhao
- College of Life Science, Yantai University, Yantai, P.R. China
| | - Longbo Cui
- College of Life Science, Yantai University, Yantai, P.R. China
| | - Jianhai Hou
- College of Life Science, Yantai University, Yantai, P.R. China
| | - Hui Shi
- College of Life Science, Yantai University, Yantai, P.R. China
| |
Collapse
|
10
|
Arevalo JA, Vázquez-Medina JP. The Role of Peroxiredoxin 6 in Cell Signaling. Antioxidants (Basel) 2018; 7:antiox7120172. [PMID: 30477202 PMCID: PMC6316032 DOI: 10.3390/antiox7120172] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 11/17/2018] [Accepted: 11/20/2018] [Indexed: 12/20/2022] Open
Abstract
Peroxiredoxin 6 (Prdx6, 1-cys peroxiredoxin) is a unique member of the peroxiredoxin family that, in contrast to other mammalian peroxiredoxins, lacks a resolving cysteine and uses glutathione and π glutathione S-transferase to complete its catalytic cycle. Prdx6 is also the only peroxiredoxin capable of reducing phospholipid hydroperoxides through its glutathione peroxidase (Gpx) activity. In addition to its peroxidase activity, Prdx6 expresses acidic calcium-independent phospholipase A2 (aiPLA2) and lysophosphatidylcholine acyl transferase (LPCAT) activities in separate catalytic sites. Prdx6 plays crucial roles in lung phospholipid metabolism, lipid peroxidation repair, and inflammatory signaling. Here, we review how the distinct activities of Prdx6 are regulated during physiological and pathological conditions, in addition to the role of Prdx6 in cellular signaling and disease.
Collapse
Affiliation(s)
- José A Arevalo
- Department of Integrative Biology, University of California, Berkeley, CA, 94705, USA.
| | | |
Collapse
|
11
|
Wahlig S, Lovatt M, Mehta JS. Functional role of peroxiredoxin 6 in the eye. Free Radic Biol Med 2018; 126:210-220. [PMID: 30120980 DOI: 10.1016/j.freeradbiomed.2018.08.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/13/2018] [Accepted: 08/14/2018] [Indexed: 10/28/2022]
Abstract
Peroxiredoxin 6 (Prdx6) is the only mammalian 1-Cys member of the Prdx family, a group of enzymes which share the ability to reduce peroxides. In addition to its peroxidase function, Prdx6 also demonstrates phospholipase A2 and lysophosphatidylcholine acyl transferase (LPCAT) activities. These enzymatic activities play an important role in regenerating oxidized membrane phospholipids and maintaining an appropriate balance of intracellular reactive oxygen species. Development of clinical pathologies, including those within the eye, have been linked to dysregulation of Prdx6 function. Interplay between external stressors like exposure to UV light, transforming growth factor β (TGF-β), and hyperglycemia in conjunction with diminished Prdx6 levels and loss of redox balance is associated with cellular changes in a variety of ophthalmic pathologies including cataracts, glaucoma, and retinal degeneration. Many of these cellular abnormalities can be rescued through supplementation with exogenous Prdx6. Additionally, corneal endothelial cells have been found to express high levels of Prdx6 in the plasma membrane. These findings highlight the importance of Prdx6 as an essential regulator of oxidative stress in the eye.
Collapse
Affiliation(s)
- Stephen Wahlig
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute (SERI), Singapore; Duke University School of Medicine, Durham, NC, USA
| | - Matthew Lovatt
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute (SERI), Singapore
| | - Jodhbir S Mehta
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute (SERI), Singapore; Singapore National Eye Center (SNEC), Singapore; Eye-ACP, Duke-NUS Graduate Medical School, Singapore.
| |
Collapse
|
12
|
Zhu L, Li J, Wu D, Li B. The protective effect of beta-casomorphin-7 via promoting Foxo1 activity and nuclear translocation in human lens epithelial cells. Cutan Ocul Toxicol 2018; 37:267-274. [PMID: 29519181 DOI: 10.1080/15569527.2018.1445095] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/10/2018] [Accepted: 02/20/2018] [Indexed: 10/17/2022]
Abstract
PURPOSE To investigate the protective effect of beta-casomorphin-7 (β-CM-7) in oxidative stressed human lens epithelial cells (HLECs) and to explore the possible mechanism for oxidative stress in HLECs induced by high glucose. METHODS We used HLECs to determine the effect of different concentrations of β-CM-7 on cell viability by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolimol/L bromide (MTT) assay. We used flow cytometry to determine the content of reactive oxygen species (ROS) induced by oxidative stress and a bioassay kit to determine the oxidant malondialdehyde (MDA) and antioxidant enzyme superoxide dismutase (SOD) levels. We used Western blotting and an immunofluorescence assay to determine the expression of Forkhead box o1 (Foxo1), SP1, and the related protein glutathione peroxidase (GSH-px) at the molecular biology level as well as their intracellular localization. RESULTS The expression of Foxo1 and SP1 was weakly expressed when the glucose concentration was 40 mM/L, but was highly expressed when cells were pre-treated with an appropriate concentration of β-CM-7. After pre-treatment with β-CM-7, the cells treated with 40 mM/L glucose for 48 h showed Foxo1 was transferred to the nucleus, and the expression of SP1 was increased. The content of ROS and MDA in the HLECs that were pre-treated with β-CM-7 was lower than in those that was not pre-treated (p <0.05). Accordingly, SOD was elevated in the cells pre-treated with β-CM-7. The relative expression of GSH-px increased with increases of Foxo1 and SP1. CONCLUSION β-CM-7 protects HLECs from oxidative damage by upregulating the relative expression of Foxo1 and promoting Foxo1 nuclear translocation.
Collapse
Affiliation(s)
- Lihua Zhu
- a Department of Ophthalmology , Jinzhou Medical University , Jinzhou , People's Republic of China
| | - Jia Li
- b Department of Ophthalmology , The First Affiliated Hospital of Jinzhou Medical University , Jinzhou , People's Republic of China
| | - Dayang Wu
- b Department of Ophthalmology , The First Affiliated Hospital of Jinzhou Medical University , Jinzhou , People's Republic of China
| | - Bing Li
- b Department of Ophthalmology , The First Affiliated Hospital of Jinzhou Medical University , Jinzhou , People's Republic of China
| |
Collapse
|
13
|
Fisher AB. The phospholipase A 2 activity of peroxiredoxin 6. J Lipid Res 2018; 59:1132-1147. [PMID: 29716959 DOI: 10.1194/jlr.r082578] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/30/2018] [Indexed: 12/21/2022] Open
Abstract
Peroxiredoxin 6 (Prdx6) is a Ca2+-independent intracellular phospholipase A2 (called aiPLA2) that is localized to cytosol, lysosomes, and lysosomal-related organelles. Activity is minimal at cytosolic pH but is increased significantly with enzyme phosphorylation, at acidic pH, and in the presence of oxidized phospholipid substrate; maximal activity with phosphorylated aiPLA2 is ∼2 µmol/min/mg protein. Prdx6 is a "moonlighting" protein that also expresses glutathione peroxidase and lysophosphatidylcholine acyl transferase activities. The catalytic site for aiPLA2 activity is an S32-H26-D140 triad; S32-H26 is also the phospholipid binding site. Activity is inhibited by a serine "protease" inhibitor (diethyl p-nitrophenyl phosphate), an analog of the PLA2 transition state [1-hexadecyl-3-(trifluoroethyl)-sn-glycero-2-phosphomethanol (MJ33)], and by two naturally occurring proteins (surfactant protein A and p67phox), but not by bromoenol lactone. aiPLA2 activity has important physiological roles in the turnover (synthesis and degradation) of lung surfactant phospholipids, in the repair of peroxidized cell membranes, and in the activation of NADPH oxidase type 2 (NOX2). The enzyme has been implicated in acute lung injury, carcinogenesis, neurodegenerative diseases, diabetes, male infertility, and sundry other conditions, although its specific roles have not been well defined. Protein mutations and animal models are now available to further investigate the roles of Prdx6-aiPLA2 activity in normal and pathological physiology.
Collapse
Affiliation(s)
- Aron B Fisher
- Institute for Environmental Medicine of the Department of Physiology, University of Pennsylvania, Philadelphia, PA 19103
| |
Collapse
|
14
|
Li YL, Qi RQ, Yang Y, Wang HX, Jiang HH, Li ZX, Xiao BH, Zheng S, Hong YX, Li JH, Chen HD, Gao XH. Screening and identification of differentially expressed serum proteins in patients with vitiligo using two‑dimensional gel electrophoresis coupled with mass spectrometry. Mol Med Rep 2017; 17:2651-2659. [PMID: 29207142 DOI: 10.3892/mmr.2017.8159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 11/22/2017] [Indexed: 11/06/2022] Open
Abstract
In the clinic, vitiligo is characterized by two stages: Stable and progressive. The pathogenesis of vitiligo is still not clear. Here, we identified serum markers of vitiligo by screening for differentially expressed proteins in patients with vitiligo compared to healthy individuals. Serum samples were collected from patients with vitiligo (n=10 for both the stable and progressive stages) and healthy individuals (n=10). Two‑dimensional gel electrophoresis followed by matrix‑assisted laser desorption/ionization time‑of‑flight mass spectrometry and western blotting were used to validate the differential expression of the proteins in the serum (n=20 each, at both stages for patients and healthy individuals). A total of 48 differentially expressed proteins were identified by gel image analysis. There were 28 differentially expressed proteins in patients with progressive vitiligo (PV) and 13 differentially expressed proteins in patients with stable vitiligo (SV) compared with that in healthy individuals. Additionally, 7 differentially expressed proteins were identified in patients with PV compared with those in patients with SV. The western blotting results showed that Peroxiredoxin‑6, apolipoprotein L1, apolipoprotein E and mannose‑binding protein were differentially expressed in patients with different stages of vitiligo. Our results showed that change serum levels of several proteins might be useful as biomarkers or in understanding the pathogenesis of vitiligo.
Collapse
Affiliation(s)
- Yi-Lei Li
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Rui-Qun Qi
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yang Yang
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - He-Xiao Wang
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Hang-Hang Jiang
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Zheng-Xiu Li
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Bi-Huan Xiao
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Song Zheng
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yu-Xiao Hong
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Jiu-Hong Li
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Hong-Duo Chen
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Xing-Hua Gao
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| |
Collapse
|
15
|
Prdx6 Upregulation by Curcumin Attenuates Ischemic Oxidative Damage via SP1 in Rats after Stroke. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6597401. [PMID: 28596967 PMCID: PMC5449737 DOI: 10.1155/2017/6597401] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/26/2017] [Indexed: 12/11/2022]
Abstract
Background The role of Peroxiredoxin 6 (Prdx6) in brain ischemia remains unclear. Curcumin (Cur) treatment elicits neuroprotective effects against cerebral ischemic injury, and the associated mechanisms may involve Prdx6. In this study, we investigated whether Prdx6 and the transcription factor specific protein 1 (SP1) were involved in the antioxidant effect of Cur after stoke. Methods Focal cerebral ischemic injury was induced by transient middle cerebral artery occlusion for 2 hours in male Sprague-Dawley rats treated with or without Prdx6 siRNA. Expression of Prdx6 in the penumbra was assessed by Real-Time PCR (RT-PCR), Western blot analysis, and immunoflourescent staining. In addition, infarct volume, neurological deficit score, and oxidative stress were evaluated. Prdx6 levels were also determined in the presence and absence of SP1 antagonist mithramycin A (MTM-A). Results Cur treatment upregulated Prdx6 protein expression and the number of Prdx6-positive neuronal cells 24 hours after reperfusion. Cur treatment also attenuated oxidative stress and induced neuroprotective effects against ischemic damage, whereas the beneficial effects of Cur treatment were lost in animals treated with Prdx6-siRNA. Prdx6 upregulation by Cur treatment was abolished by SP1 antagonists MTM. Conclusions Prdx6 upregulation by Cur treatment attenuates ischemic oxidative damage through SP1 induction in rats after stroke. This represents a novel mechanism of Cur-induced neuroprotection against cerebral ischemia.
Collapse
|