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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.
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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
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MAPK Pathways in Ocular Pathophysiology: Potential Therapeutic Drugs and Challenges. Cells 2023; 12:cells12040617. [PMID: 36831285 PMCID: PMC9954064 DOI: 10.3390/cells12040617] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/05/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways represent ubiquitous cellular signal transduction pathways that regulate all aspects of life and are frequently altered in disease. Once activated through phosphorylation, these MAPKs in turn phosphorylate and activate transcription factors present either in the cytoplasm or in the nucleus, leading to the expression of target genes and, as a consequence, they elicit various biological responses. The aim of this work is to provide a comprehensive review focusing on the roles of MAPK signaling pathways in ocular pathophysiology and the potential to influence these for the treatment of eye diseases. We summarize the current knowledge of identified MAPK-targeting compounds in the context of ocular diseases such as macular degeneration, cataract, glaucoma and keratopathy, but also in rare ocular diseases where the cell differentiation, proliferation or migration are defective. Potential therapeutic interventions are also discussed. Additionally, we discuss challenges in overcoming the reported eye toxicity of some MAPK inhibitors.
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Wang DN, Ni JJ, Li JH, Gao YQ, Ni FJ, Zhang ZZ, Fang JY, Lu J, Yao YF. Bacterial infection promotes tumorigenesis of colorectal cancer via regulating CDC42 acetylation. PLoS Pathog 2023; 19:e1011189. [PMID: 36812247 PMCID: PMC9987831 DOI: 10.1371/journal.ppat.1011189] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 03/06/2023] [Accepted: 02/07/2023] [Indexed: 02/24/2023] Open
Abstract
Increasing evidence highlights the role of bacteria in promoting tumorigenesis. The underlying mechanisms may be diverse and remain poorly understood. Here, we report that Salmonella infection leads to extensive de/acetylation changes in host cell proteins. The acetylation of mammalian cell division cycle 42 (CDC42), a member of the Rho family of GTPases involved in many crucial signaling pathways in cancer cells, is drastically reduced after bacterial infection. CDC42 is deacetylated by SIRT2 and acetylated by p300/CBP. Non-acetylated CDC42 at lysine 153 shows an impaired binding of its downstream effector PAK4 and an attenuated phosphorylation of p38 and JNK, consequently reduces cell apoptosis. The reduction in K153 acetylation also enhances the migration and invasion ability of colon cancer cells. The low level of K153 acetylation in patients with colorectal cancer (CRC) predicts a poor prognosis. Taken together, our findings suggest a new mechanism of bacterial infection-induced promotion of colorectal tumorigenesis by modulation of the CDC42-PAK axis through manipulation of CDC42 acetylation.
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Affiliation(s)
- Dan-Ni Wang
- Laboratory of Bacterial Pathogenesis, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin-Jing Ni
- Laboratory of Bacterial Pathogenesis, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-Hui Li
- Laboratory of Bacterial Pathogenesis, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Phage, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Ya-Qi Gao
- State Key Laboratory for Oncogenes and Related Genes; Division of Gastroenterology and Hepatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fang-Jing Ni
- Laboratory of Bacterial Pathogenesis, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhen-Zhen Zhang
- Department of Pathology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing-Yuan Fang
- State Key Laboratory for Oncogenes and Related Genes; Division of Gastroenterology and Hepatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jie Lu
- Department of Infectious Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- * E-mail: (JL); (Y-FY)
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Infectious Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
- * E-mail: (JL); (Y-FY)
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Tong Y, Zhang Z, Wang S. Role of Mitochondria in Retinal Pigment Epithelial Aging and Degeneration. FRONTIERS IN AGING 2022; 3:926627. [PMID: 35912040 PMCID: PMC9337215 DOI: 10.3389/fragi.2022.926627] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/21/2022] [Indexed: 12/17/2022]
Abstract
Retinal pigment epithelial (RPE) cells form a monolayer between the neuroretina and choroid. It has multiple important functions, including acting as outer blood-retina barrier, maintaining the function of neuroretina and photoreceptors, participating in the visual cycle and regulating retinal immune response. Due to high oxidative stress environment, RPE cells are vulnerable to dysfunction, cellular senescence, and cell death, which underlies RPE aging and age-related diseases, including age-related macular degeneration (AMD). Mitochondria are the powerhouse of cells and a major source of cellular reactive oxygen species (ROS) that contribute to mitochondrial DNA damage, cell death, senescence, and age-related diseases. Mitochondria also undergo dynamic changes including fission/fusion, biogenesis and mitophagy for quality control in response to stresses. The role of mitochondria, especially mitochondrial dynamics, in RPE aging and age-related diseases, is still unclear. In this review, we summarize the current understanding of mitochondrial function, biogenesis and especially dynamics such as morphological changes and mitophagy in RPE aging and age-related RPE diseases, as well as in the biological processes of RPE cellular senescence and cell death. We also discuss the current preclinical and clinical research efforts to prevent or treat RPE degeneration by restoring mitochondrial function and dynamics.
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Affiliation(s)
- Yao Tong
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
| | - Zunyi Zhang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
| | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, United States
- Department of Ophthalmology, Tulane University, New Orleans, LA, United States
- Tulane Personalized Health Institute, Tulane University, New Orleans, LA, United States
- *Correspondence: Shusheng Wang,
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Arctigenin Enhances the Cytotoxic Effect of Doxorubicin in MDA-MB-231 Breast Cancer Cells. Int J Mol Sci 2020; 21:ijms21082997. [PMID: 32340377 PMCID: PMC7215735 DOI: 10.3390/ijms21082997] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/21/2020] [Accepted: 04/21/2020] [Indexed: 12/23/2022] Open
Abstract
Several reports have described the anti-cancer activity of arctigenin, a lignan extracted from Arctium lappa L. Here, we investigated the effect of arctigenin (ATG) on doxorubicin (DOX)-induced cell death using MDA-MB-231 human breast cancer cells. The results showed that DOX-induced cell death was enhanced by ATG/DOX co-treatment in a concentration-dependent manner and that this was associated with increased DOX uptake and the suppression of multidrug resistance-associated protein 1 (MRP1) gene expression in MDA-MB-231 cells. ATG enhanced DOX-induced DNA damage and decreased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and the expressions of RAD51 and survivin. Cell death caused by ATG/DOX co-treatment was mediated by the nuclear translocation of apoptosis inducing factor (AIF), reductions in cellular and mitochondrial Bcl-2 and Bcl-xL, and increases in mitochondrial BAX levels. However, caspase-3 and -7 did not participate in DOX/ATG-induced cell death. We also found that DOX/ATG-induced cell death was linked with activation of the p38 signaling pathway and suppressions of the phosphorylations and expressions of Akt and c-Jun N-terminal kinase. Taken together, these results show that ATG enhances the cytotoxic activity of DOX in MDA-MB-231 human breast cancer cells by inducing prolonged p21 expression and p38-mediated AIF-dependent cell death. In conclusion, our findings suggest that ATG might alleviate the side effects and improve the therapeutic efficacy of DOX.
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Xu Y, Wang L, Cao L, Chen L, Liu Q. Involvement of NYD-SP15 in growth and oxidative-stress responses of ARPE-19. J Cell Biochem 2019; 120:1362-1375. [PMID: 30368880 DOI: 10.1002/jcb.27104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 05/07/2018] [Indexed: 01/24/2023]
Abstract
The aim of this study was to investigate the role of NYD-SP15 in the growth and oxidative-stress responses of ARPE-19 cells. ARPE-19 cell lines overexpressing wild type or RNA interference against NYD-SP15 were established via lentivirus transfection. Cell growth and proliferation, migration, apoptosis, and cell cycle progression were monitored using the Cell Counting Kit-8 assay, the wound scratch assay, and flow cytometry, respectively. Caspase-3/8/9 activity was examined using the caspase-3/8/9 assay kit. An hydrogen peroxide (H 2 O 2 )-induced oxidative-stress damage model was used to study the effect of NYD-SP15 knockdown by examining the activity of reactive oxygen species (ROS). Expressions of Kelch-like ECH-associated protein 1 (Keap-1)/heme oxygenase-1 (HO-1)/nuclear factor erythroid 2-related factor 2 (Nrf2), mitogen-activated protein kinase (MAPK), and Akt were detected by Western blot analysis. The mRNA chip of NYD-SP15 overexpressed ARPE-19 cells as well as controls were performed by one array plus process. Overexpression (OE) of NYD-SP15 inhibited the proliferation and migration of ARPE-19 cells, and led to apoptosis and caspase-3/9 activation. OE of NYD-SP15 inhibited MAPKs and Akt signaling. Downregulation of NYD-SP15 had no effect on the growth of normally cultured ARP19 cells with 10% fetal bovine serum, but promoted the growth of ARP19 cells in the presence of starvation challenge. Gene chip showed that OE of NYD-SP15 led to downregulation of 254 genes and upregulation of 57 genes. Downregulation of NYD-SP15 also exerted a protective effect on H 2 O 2 -induced cell apoptosis and ROS. NYD-SP15 downregulation led to increments in the expression of Nrf2, Keap-1, and HO-1 in response to 200 μM H 2 O 2 . NYD-SP15 might inhibit the growth, proliferation, and migration and promote apoptosis of ARPE-19 cells via MAPK and Akt signaling. Downregulation of NYD-SP15 could protect ARPE-19 cells from H 2 O 2 -induced oxidative damage by active Keap-1/HO-1/Nrf2, Akt, and MAPK signaling.
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Affiliation(s)
- Yidan Xu
- Department of Ophthalmology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210000, Jiangsu, China
| | - Linnong Wang
- Department of Ophthalmology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210000, Jiangsu, China
| | - Liu Cao
- Department of Ophthalmology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210000, Jiangsu, China
| | - Lixun Chen
- Department of Ophthalmology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210000, Jiangsu, China
| | - Qinghuai Liu
- Department of Ophthalmology, The first affiliated Hospital of Nanjing Medical University, Nanjing 210000, Jiangsu, China
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Cheng Z, Yao W, Zheng J, Ding W, Wang Y, Zhang T, Zhu L, Zhou F. A derivative of betulinic acid protects human Retinal Pigment Epithelial (RPE) cells from cobalt chloride-induced acute hypoxic stress. Exp Eye Res 2018; 180:92-101. [PMID: 30578788 DOI: 10.1016/j.exer.2018.12.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 02/05/2023]
Abstract
The Retinal Pigment Epithelium (RPE) is a monolayer of cells located above the choroid. It mediates human visual cycle and nourishes photoreceptors. Hypoxia-induced oxidative stress to RPE is a vital cause of retinal degeneration such as the Age-related Macular Degeneration. Most of these retinal diseases are irreversible with no efficient treatment, therefore protecting RPE cells from hypoxia stress is an important way to prevent or slow down the progression of retinal degeneration. Betulinic acid (BA) and betulin (BE) are pentacyclic triterpenoids with anti-oxidative property, but little is known about their effect on RPE cells. We investigated the protective effect of BA, BE and their derivatives against cobalt chloride-induced hypoxia stress in RPE cells. Human ARPE-19 cells were exposed to BA, BE and their eighteen derivatives (named as H3H20) that we customized through replacing moieties at C3 and C28 positions. We found that cobalt chloride reduced cell viability, increased Reactive Oxygen Species (ROS) production as well as induced apoptosis and necrosis in ARPE-19 cells. Interestingly, the pretreatment of 3-O-acetyl-glycyl- 28-O-glycyl-betulinic acid effectively protected cells from acute hypoxia stress induced by cobalt chloride. Our immunoblotting results suggested that this derivative attenuated the cobalt chloride-induced activation of Akt, Erk and JNK pathways. All findings were further validated in human primary RPE cells. In summary, this BA derivate has protective effect against the acute hypoxic stress in human RPE cells and may be developed into a candidate agent effective in the prevention of prevalent retinal diseases.
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Affiliation(s)
- Zhengqi Cheng
- School of Pharmacy, The University of Sydney, NSW, 2006, Australia
| | - Wenjuan Yao
- School of Pharmacy, Nantong University, Nantong, Jiangsu Province, China
| | - Jian Zheng
- Center for Bioactive Products, Northeast Forestry University/Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Harbin, 150040, China
| | - Weimin Ding
- School of Chemical and Environmental Engineering, Harbin University of Science and Technology, Harbin, 150080, Heilongjiang, China
| | - Yang Wang
- Center for Bioactive Products, Northeast Forestry University/Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Harbin, 150040, China
| | - Ting Zhang
- Save Sight Institute, The University of Sydney, Sydney, NSW, 2000, Australia; State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ling Zhu
- Save Sight Institute, The University of Sydney, Sydney, NSW, 2000, Australia
| | - Fanfan Zhou
- School of Pharmacy, The University of Sydney, NSW, 2006, Australia.
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Oxidative Damages to Eye Stem Cells, in Response to, Bright and Ultraviolet Light, Their Associated Mechanisms, and Salvage Pathways. Mol Biotechnol 2018; 61:145-152. [DOI: 10.1007/s12033-018-0136-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Khalo IV, Konokhova AI, Orlova DY, Trusov KV, Yurkin MA, Bartova E, Kozubek S, Maltsev VP, Chernyshev AV. Nuclear apoptotic volume decrease in individual cells: Confocal microscopy imaging and kinetic modeling. J Theor Biol 2018; 454:60-69. [PMID: 29859212 DOI: 10.1016/j.jtbi.2018.05.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 05/13/2018] [Accepted: 05/28/2018] [Indexed: 11/29/2022]
Abstract
The dynamics of nuclear morphology changes during apoptosis remains poorly investigated and understood. Using 3D time-lapse confocal microscopy we performed a study of early-stage apoptotic nuclear morphological changes induced by etoposide in single living HepG2 cells. These observations provide a definitive evidence that nuclear apoptotic volume decrease (AVD) is occurring simultaneously with peripheral chromatin condensation (so called "apoptotic ring"). In order to describe quantitatively the dynamics of nuclear morphological changes in the early stage of apoptosis we suggest a general molecular kinetic model, which fits well the obtained experimental data in our study. Results of this work may clarify molecular mechanisms of nuclear morphology changes during apoptosis.
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Affiliation(s)
- Irina V Khalo
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya 3, Novosibirsk 630090, Russia
| | - Anastasiya I Konokhova
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya 3, Novosibirsk 630090, Russia
| | - Darya Y Orlova
- Department of Genetics, Stanford University, Campus Drive 279, Stanford, CA 94305, USA
| | - Konstantin V Trusov
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya 3, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia
| | - Maxim A Yurkin
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya 3, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia
| | - Eva Bartova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, Brno CZ-612 65, Czech Republic
| | - Stanislav Kozubek
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, Brno CZ-612 65, Czech Republic
| | - Valeri P Maltsev
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya 3, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia; Novosibirsk State Medical University, Krasny Prospect 52, Novosibirsk 630091, Russia
| | - Andrei V Chernyshev
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya 3, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia.
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Sun Y, Zheng Y, Wang C, Liu Y. Glutathione depletion induces ferroptosis, autophagy, and premature cell senescence in retinal pigment epithelial cells. Cell Death Dis 2018; 9:753. [PMID: 29988039 PMCID: PMC6037763 DOI: 10.1038/s41419-018-0794-4] [Citation(s) in RCA: 321] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/09/2018] [Accepted: 06/14/2018] [Indexed: 12/28/2022]
Abstract
Glutathione (GSH) protects against oxidative damage in many tissues, including retinal pigment epithelium (RPE). Oxidative stress-mediated senescence and death of RPE and subsequent death of photoreceptors have been observed in age-related macular degeneration (AMD). Although the consequences of GSH depletion have been described previously, questions remain regarding the molecular mechanisms. We herein examined the downstream effects of GSH depletion on stress-induced premature senescence (SIPS) and cell death in human RPE cells. Briefly, cultured ARPE-19 cells were depleted of GSH using: (1) incubation in cystine (Cys2)-free culture medium; (2) treatment with buthionine sulphoximine (BSO, 1000 µM) to block de novo GSH synthesis for 24-48 h; or (3) treatment with erastin (10 µM for 12-24 h) to inhibit Cys2/glutamate antiporter (system xc-). These treatments decreased cell viability and increased both soluble and lipid reactive oxygen species (ROS) generation but did not affect mitochondrial ROS or mitochondrial mass. Western blot analysis revealed decreased expression of ferroptotic modulator glutathione peroxidase 4 (GPX4). Increased autophagy was apparent, as reflected by increased LC3 expression, autophagic vacuoles, and autophagic flux. In addition, GSH depletion induced SIPS, as evidenced by increased percentage of the senescence-associated β-galactosidase-positive cells, increased senescence-associated heterochromatin foci (SAHF), as well as cell cycle arrest at the G1 phase. GSH depletion-dependent cell death was prevented by selective ferroptosis inhibitors (8 μM Fer-1 and 600 nM Lip-1), iron chelator DFO (80 μM), as well as autophagic inhibitors Baf-A1 (75 nM) and 3-MA (10 mM). Inhibiting autophagy with Baf-A1 (75 nM) or 3-MA (10 mM) promoted SIPS. In contrast, inducing autophagy with rapamycin (100 nM) attenuated SIPS. Our findings suggest that GSH depletion induces ferroptosis, autophagy, and SIPS. In addition, we found that autophagy is activated in the process of ferroptosis and reduces SIPS, suggesting an essential role of autophagy in ferroptosis and SIPS.
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Affiliation(s)
- Yun Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yingfeng Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Chunxiao Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
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Age-Related Macular Degeneration: New Paradigms for Treatment and Management of AMD. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8374647. [PMID: 29484106 PMCID: PMC5816845 DOI: 10.1155/2018/8374647] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 12/06/2017] [Indexed: 12/03/2022]
Abstract
Age-related macular degeneration (AMD) is a well-characterized and extensively studied disease. It is currently considered the leading cause of visual disability among patients over 60 years. The hallmark of early AMD is the formation of drusen, pigmentary changes at the macula, and mild to moderate vision loss. There are two forms of AMD: the “dry” and the “wet” form that is less frequent but is responsible for 90% of acute blindness due to AMD. Risk factors have been associated with AMD progression, and they are taking relevance to understand how AMD develops: (1) advanced age and the exposition to environmental factors inducing high levels of oxidative stress damaging the macula and (2) this damage, which causes inflammation inducing a vicious cycle, altogether causing central vision loss. There is neither a cure nor treatment to prevent AMD. However, there are some treatments available for the wet form of AMD. This article will review some molecular and cellular mechanisms associated with the onset of AMD focusing on feasible treatments for each related factor in the development of this pathology such as vascular endothelial growth factor, oxidative stress, failure of the clearance of proteins and organelles, and glial cell dysfunction in AMD.
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12
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Fong-Ngern K, Ausakunpipat N, Singhto N, Sueksakit K, Thongboonkerd V. Prolonged K + deficiency increases intracellular ATP, cell cycle arrest and cell death in renal tubular cells. Metabolism 2017; 74:47-61. [PMID: 28095989 DOI: 10.1016/j.metabol.2016.12.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 12/02/2016] [Accepted: 12/28/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND Chronic potassium (K+) deficiency can cause renal damage namely hypokalemic nephropathy with unclear pathogenic mechanisms. In the present study, we investigated expression and functional alterations in renal tubular cells induced by prolonged K+ deficiency. METHODS MDCK cells were maintained in normal-K+ (CNK) (K+=5.3mmol/L), low-K+ (CLK) (K+=2.5mmol/L), or K+-depleted (CKD) (K+=0mmol/L) medium for 10days (n=5 independent cultures/condition). Differentially expressed proteins were identified by a proteomics approach followed by various functional assays. RESULTS Proteomic analysis revealed 46 proteins whose levels significantly differed among groups. The proteomic data were confirmed by Western blotting. Gene Ontology (GO) classification and protein network analysis revealed that majority of the altered proteins participated in metabolic process, whereas the rest involved in cellular component organization/biogenesis, cellular process (e.g., cell cycle, regulation of cell death), response to stress, and signal transduction. Interestingly, ATP measurement revealed that intracellular ATP production was increased in CLK and maximum in CKD. Flow cytometry showed cell cycle arrest at S-phase and G2/M-phase in CLK and CKD, respectively, consistent with cell proliferation and growth assays, which showed modest and marked degrees of delayed growth and prolonged doubling time in CLK and CKD, respectively. Cell death quantification also revealed modest and marked degrees of increased cell death in CLK and CKD, respectively. CONCLUSIONS In conclusion, prolonged K+ deficiency increased intracellular ATP, cell cycle arrest and cell death in renal tubular cells, which might be responsible for mechanisms underlying the development of hypokalemic nephropathy.
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Affiliation(s)
- Kedsarin Fong-Ngern
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, and Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
| | - Nardtaya Ausakunpipat
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, and Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
| | - Nilubon Singhto
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, and Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
| | - Kanyarat Sueksakit
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, and Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
| | - Visith Thongboonkerd
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, and Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand.
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13
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Kyosseva SV. Targeting MAPK Signaling in Age-Related Macular Degeneration. OPHTHALMOLOGY AND EYE DISEASES 2016; 8:23-30. [PMID: 27385915 PMCID: PMC4920203 DOI: 10.4137/oed.s32200] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/08/2016] [Accepted: 05/13/2016] [Indexed: 12/26/2022]
Abstract
Age-related macular degeneration (AMD) is a major cause of irreversible blindness affecting elderly people in the world. AMD is a complex multifactorial disease associated with demographic, genetics, and environmental risk factors. It is well established that oxidative stress, inflammation, and apoptosis play critical roles in the pathogenesis of AMD. The mitogen-activated protein kinase (MAPK) signaling pathways are activated by diverse extracellular stimuli, including growth factors, mitogens, hormones, cytokines, and different cellular stressors such as oxidative stress. They regulate cell proliferation, differentiation, survival, and apoptosis. This review addresses the novel findings from human and animal studies on the relationship of MAPK signaling with AMD. The use of specific MAPK inhibitors may represent a potential therapeutic target for the treatment of this debilitating eye disease.
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Affiliation(s)
- Svetlana V Kyosseva
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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14
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Zhu Y, Zhao KK, Tong Y, Zhou YL, Wang YX, Zhao PQ, Wang ZY. Exogenous NAD(+) decreases oxidative stress and protects H2O2-treated RPE cells against necrotic death through the up-regulation of autophagy. Sci Rep 2016; 6:26322. [PMID: 27240523 PMCID: PMC4886526 DOI: 10.1038/srep26322] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 05/03/2016] [Indexed: 01/08/2023] Open
Abstract
Increased oxidative stress, which can lead to the retinal pigment epithelium (RPE) cell death by inducing ATP depletion and DNA repair, is believed to be a prominent pathology in age-related macular degeneration (AMD). In the present study, we showed that and 0.1 mM nicotinamide adenine dinucleotide (NAD+) administration significantly blocked RPE cell death induced by 300 μM H2O2. Further investigation showed that H2O2 resulted in increased intracellular ROS level, activation of PARP-1 and subsequently necrotic death of RPE cells. Exogenous NAD+ administration significantly decreased intracellular and intranuclear ROS levels in H2O2-treated RPE cells. In addition, NAD+ administration to H2O2-treated RPE cells inhibited the activation of PARP-1 and protected the RPE cells against necrotic death. Moreover, exogenous NAD+ administration up-regulated autophagy in the H2O2-treated RPE cells. Inhibition of autophagy by LY294002 blocked the decrease of intracellular and intranuclear ROS level. Besides, inhibition of autophagy by LY294002 abolished the protection of exogenous NAD+ against H2O2-induced cell necrotic death. Taken together, our findings indicate that that exogenous NAD+ administration suppresses H2O2-induced oxidative stress and protects RPE cells against PARP-1 mediated necrotic death through the up-regulation of autophagy. The results suggest that exogenous NAD+ administration might be potential value for the treatment of AMD.
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Affiliation(s)
- Ying Zhu
- Department of Ophthalmology, Xinhua Hospital, Shanghai Jiaotong University Scool of Medicine, Shanghai, China
| | - Ke-Ke Zhao
- Department of Ophthalmology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yao Tong
- Department of Ophthalmology, Xinhua Hospital, Shanghai Jiaotong University Scool of Medicine, Shanghai, China
| | - Ya-Li Zhou
- Department of Ophthalmology, Xinhua Hospital, Shanghai Jiaotong University Scool of Medicine, Shanghai, China
| | - Yi-Xiao Wang
- Department of Ophthalmology, Xinhua Hospital, Shanghai Jiaotong University Scool of Medicine, Shanghai, China
| | - Pei-Quan Zhao
- Department of Ophthalmology, Xinhua Hospital, Shanghai Jiaotong University Scool of Medicine, Shanghai, China
| | - Zhao-Yang Wang
- Department of Ophthalmology, Xinhua Hospital, Shanghai Jiaotong University Scool of Medicine, Shanghai, China
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15
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Hanus J, Anderson C, Wang S. RPE necroptosis in response to oxidative stress and in AMD. Ageing Res Rev 2015; 24:286-98. [PMID: 26369358 PMCID: PMC4661094 DOI: 10.1016/j.arr.2015.09.002] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/19/2015] [Accepted: 09/09/2015] [Indexed: 12/19/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly. The underlying mechanism of non-neovascular AMD (dry AMD), also named geographic atrophy (GA) remains unclear and the mechanism of retinal pigment epithelial (RPE) cell death in AMD is controversial. We review the history and recent progress in understanding the mechanism of RPE cell death induced by oxidative stress, in AMD mouse models, and in AMD patients. Due to the limitation of toolsets to distinguish between apoptosis and necroptosis (or necrosis), most previous research concludes that apoptosis is a major mechanism for RPE cell death in response to oxidative stress and in AMD. Recent studies suggest necroptosis as a major mechanism of RPE cell death in response to oxidative stress. Moreover, ultrastructural and histopathological studies support necrosis as major mechanism of RPE cells death in AMD. In this review, we discuss the mechanism of RPE cell death in response to oxidative stress, in AMD mouse models, and in human AMD patients. Based on the literature, we hypothesize that necroptosis is a major mechanism for RPE cell death in response to oxidative stress and in AMD.
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Affiliation(s)
- Jakub Hanus
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Chastain Anderson
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Shusheng Wang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA; Department of Ophthalmology, Tulane University, New Orleans, LA 70118, USA.
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16
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Mei W, Peng Z, Lu M, Liu C, Deng Z, Xiao Y, Liu J, He Y, Yuan Q, Yuan X, Tang D, Yang H, Tao L. Peroxiredoxin 1 inhibits the oxidative stress induced apoptosis in renal tubulointerstitial fibrosis. Nephrology (Carlton) 2015; 20:832-42. [PMID: 25989822 DOI: 10.1111/nep.12515] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2015] [Indexed: 02/06/2023]
Affiliation(s)
- Wenjuan Mei
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
| | - Zhangzhe Peng
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
| | - Miaomiao Lu
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
| | - Chunyan Liu
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
| | - Zhenghao Deng
- Division of Pathology; Xiangya Hospital; Central South University; Changsha China
| | - Yun Xiao
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
| | - Jishi Liu
- Division of Nephrology; The Third Xiangya Hospital; Central South University; Changsha China
| | - Ying He
- Division of Gastroenterology; Xiangya Hospital; Central South University; Changsha China
| | - Qiongjing Yuan
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
| | - Xiangning Yuan
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
| | - Damu Tang
- Division of Nephrology; Department of Medicine; McMaster University; Hamilton Ontario Canada
| | - Huixiang Yang
- Division of Gastroenterology; Xiangya Hospital; Central South University; Changsha China
| | - Lijian Tao
- Division of Nephrology; Xiangya Hospital; Central South University; Changsha China
- State Key Laboratory of Medical Genetics of China; Central South University; Changsha China
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17
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Chan CM, Huang CH, Li HJ, Hsiao CY, Su CC, Lee PL, Hung CF. Protective effects of resveratrol against UVA-induced damage in ARPE19 cells. Int J Mol Sci 2015; 16:5789-802. [PMID: 25775159 PMCID: PMC4394506 DOI: 10.3390/ijms16035789] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 02/25/2015] [Accepted: 03/04/2015] [Indexed: 02/03/2023] Open
Abstract
Ultraviolet radiation, especially UVA, can penetrate the lens, reach the retina, and induce oxidative stress to retinal pigment epithelial (RPE) cells. Even though it is weakly absorbed by protein and DNA, it may trigger the production of reactive oxygen species (ROS) and generate oxidative injury; oxidative injury to the retinal pigment epithelium has been implicated to play a contributory role in age-related macular degeneration (AMD). Studies showed that resveratrol, an abundant and active component of red grapes, can protect several cell types from oxidative stress. In this study, adult RPE cells being treated with different concentrations of resveratrol were used to evaluate the protective effect of resveratrol on RPE cells against UVA-induced damage. Cell viability assay showed that resveratrol reduced the UVA-induced decrease in RPE cell viability. Through flow cytometry analysis, we found that the generation of intracellular H2O2 induced by UVA irradiation in RPE cells could be suppressed by resveratrol in a concentration-dependent manner. Results of Western blot analysis demonstrated that resveratrol lowered the activation of UVA-induced extracellular signal-regulated kinase, c-jun-NH2 terminal kinase and p38 kinase in RPE cells. In addition, there was also a reduction in UVA-induced cyclooxygenase-2 (COX-2) expression in RPE cells pretreated with resveratrol. Our observations suggest that resveratrol is effective in preventing RPE cells from being damaged by UVA radiation, and is worth considering for further development as a chemoprotective agent for the prevention of early AMD.
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Affiliation(s)
- Chi-Ming Chan
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
- Department of Ophthalmology, Cardinal Tien Hospital, Hsiendian, New Taipei City 23148, Taiwan.
| | - Cheng-Hua Huang
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
- Department of Internal Medicine, Cathay General Hospital, Taipei 10630, Taiwan.
| | - Hsin-Ju Li
- Department of Chemstry, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
| | - Chien-Yu Hsiao
- Department of Nutrition and Health Sciences, Chang Gung University of Science and Technology, Kweishan, Taoyuan 33303, Taiwan.
- Research center for Industry of Human Ecology, Chang Gung University of Science and Technology, Kweishan, Taoyuan 33303, Taiwan.
| | - Ching-Chieh Su
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
- Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
- Department of Internal Medicine, Cardinal Tien Hospital, Hsiendian, New Taipei City 23148, Taiwan.
| | - Pei-Lan Lee
- Slone Epidemiology Center, Boston University, Boston, MA 02215, USA.
| | - Chi-Feng Hung
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
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18
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Nishimoto M, Fujita T. Renal mechanisms of salt-sensitive hypertension: contribution of two steroid receptor-associated pathways. Am J Physiol Renal Physiol 2015; 308:F377-87. [DOI: 10.1152/ajprenal.00477.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Although salt is a major environmental factor in the development of hypertension, the degree of salt sensitivity varies widely among individuals. The mechanisms responsible for this variation remain to be elucidated. Recent studies have revealed the involvement of two important signaling pathways in renal tubules that play key roles in electrolyte balance and the maintenance of normal blood pressure: the β2-adrenergic stimulant-glucocorticoid receptor (GR)-with-no-lysine kinase (WNK)4-Na+-Cl− cotransporter pathway, which is active in distal convoluted tubule (DCT)1, and the Ras-related C3 botulinum toxin substrate (Rac)1-mineralocorticoid receptor (MR) pathway, which is active in DCT2, connecting tubules, and collecting ducts. β2-Adrenergic stimulation due to increased renal sympathetic activity in obesity- and salt-induced hypertension suppresses histone deacetylase 8 activity via cAMP/PKA signaling, increasing the accessibility of GRs to the negative GR response element in the WNK4 promoter. This results in the suppression of WNK4 transcription followed by the activation of Na+-Cl− cotransporters in the DCT and elevated Na+ retention and blood pressure upon salt loading. Rac1 activates MRs, even in the absence of ligand binding, with this activity increased in the presence of ligand. In salt-sensitive animals, Rac1 activation due to salt loading activates MRs in DCT2, connecting tubules, and collecting ducts. Thus, GRs and MRs are independently involved in two pathways responsible for renal Na+ handling and salt-sensitive hypertension. These findings suggest novel therapeutic targets and may lead to the development of diagnostic tools to determine salt sensitivity in hypertensive patients.
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Affiliation(s)
- Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
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19
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Hsiung J, Zhu D, Hinton DR. Polarized human embryonic stem cell-derived retinal pigment epithelial cell monolayers have higher resistance to oxidative stress-induced cell death than nonpolarized cultures. Stem Cells Transl Med 2014; 4:10-20. [PMID: 25411476 DOI: 10.5966/sctm.2014-0205] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Oxidative stress-mediated injury to the retinal pigment epithelium (RPE) is a major factor involved in the pathogenesis of age-related macular degeneration (AMD), the leading cause of blindness in the elderly. Human embryonic stem cell (hESC)-derived RPE cells are currently being evaluated for their potential for cell therapy in AMD patients through subretinal injection of cells in suspension and subretinal placement as a polarized monolayer. To gain an understanding of how transplanted RPE cells will respond to the highly oxidatively stressed environment of an AMD patient eye, we compared the survival of polarized and nonpolarized RPE cultures following oxidative stress treatment. Polarized, nonpolarized/confluent, nonpolarized/subconfluent hESC-RPE cells were treated with H2O2. Terminal deoxynucleotidyl transferase dUTP nick end labeling stains revealed the highest amount of cell death in subconfluent hESC-RPE cells and little cell death in polarized hESC-RPE cells with H2O2 treatment. There were higher levels of proapoptotic factors (phosphorylated p38, phosphorylated c-Jun NH2-terminal kinase, Bax, and cleaved caspase 3 fragments) in treated nonpolarized RPE-particularly subconfluent cells-relative to polarized cells. On the other hand, polarized RPE cells had constitutively higher levels of cell survival and antiapoptotic signaling factors such as p-Akt and Bcl-2, as well as antioxidants superoxide dismutase 1 and catalase relative to nonpolarized cells, that possibly contributed to polarized cells' higher tolerance to oxidative stress compared with nonpolarized RPE cells. Subconfluent cells were particularly sensitive to oxidative stress-induced apoptosis. These results suggest that implantation of polarized hESC-RPE monolayers for treating AMD patients with geographic atrophy should have better survival than injections of hESC-RPE cells in suspension.
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Affiliation(s)
- Jamie Hsiung
- Departments of Pathology and Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Danhong Zhu
- Departments of Pathology and Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - David R Hinton
- Departments of Pathology and Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
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20
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Koinzer S, Reinecke K, Herdegen T, Roider J, Klettner A. Oxidative Stress Induces Biphasic ERK1/2 Activation in the RPE with Distinct Effects on Cell Survival at Early and Late Activation. Curr Eye Res 2014; 40:853-7. [PMID: 25251900 DOI: 10.3109/02713683.2014.961613] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE Oxidative stress is considered a major factor in the deterioration of retinal pigment epithelium (RPE) cells in dry age-related macular degeneration (AMD). The MAPK ERK1/2 can be activated by oxidative stress, may exert both pro- and anti-apoptotic functions, and has recently been proposed as a major factor in RPE degeneration in atrophic changes. Nrf2 is a master regulator of oxidative stress defense and ERK1/2 is an upstream activator of Nrf2. In this study, we investigate the participation of ERK1/2 in oxidative stress pathways in connection with Nrf2. METHODS Nrf2 knock-out and wild-type primary RPE cells were prepared from mouse eyes. Oxidative stress was induced by different concentrations of t-butylhydroperoxide. Mitogen-activated protein kinases (MAPKs) were blocked by commercially available inhibitors (SB203580, U0126, SP600125). Cell viability was determined by MTT assay. ERK1/2 expression and activation were assessed by Western blotting. RESULTS Oxidative stress induced concentration dependent cell death, which occurred at lower concentrations in Nrf2 knock-out RPE. Western blot analysis displayed a biphasic activation of ERK1/2 in murine wild-type RPE and the inhibition of late, but not early activation of ERK1/2 exerted protection in wild-type murine RPE cells. The biphasic activation of ERK1/2 is lost in Nrf2 knock-out mice, and inhibition of ERK1/2 was generally protective. The inhibition of MAPK JNK or p38 exerted no protection, irrespective of Nrf2. CONCLUSION RPE cells display a biphasic activation of ERK1/2 after oxidative insult, of which the late activation is pro-apoptotic. The biphasic activation is lost in Nrf2 knock-outs, suggesting that early ERK1/2 activation may be connected to Nrf2 signaling. In addition, ERK1/2 activation in Nrf2 knock-outs mediates oxidative stress-induced cell death.
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21
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Ashino T, Yamamoto M, Yoshida T, Numazawa S. Redox-sensitive transcription factor Nrf2 regulates vascular smooth muscle cell migration and neointimal hyperplasia. Arterioscler Thromb Vasc Biol 2013; 33:760-8. [PMID: 23413426 DOI: 10.1161/atvbaha.112.300614] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Reactive oxygen species are important mediators for platelet-derived growth factor (PDGF) signaling in vascular smooth muscle cells, whereas excess reactive oxygen species-induced oxidative stress contributes to the development and progression of vascular diseases, such as atherosclerosis. Activation of the redox-sensitive transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), is pivotal in cellular defense against oxidative stress by transcriptional upregulation of antioxidant proteins. This study aimed to elucidate the role of Nrf2 in PDGF-mediated vascular smooth muscle cell migration and neointimal hyperplasia. APPROACH AND RESULTS PDGF promoted nuclear translocation of Nrf2, followed by the induction of target genes, including NAD(P)H:quinone oxidoreductase-1, heme oxygenase-1, and thioredoxin-1. Nrf2 depletion by small interfering RNA enhanced PDGF-promoted Rac1 activation and reactive oxygen species production and persistently phosphorylated downstream extracellular signal-regulated kinase-1/2. Nrf2 depletion enhanced vascular smooth muscle cell migration in response to PDGF and wound scratch. In vivo, Nrf2-deficient mice showed enhanced neointimal hyperplasia in a wire injury model. CONCLUSIONS These findings suggest that the Nrf2 system is important for PDGF-stimulated vascular smooth muscle cell migration by regulating reactive oxygen species elimination, which may contribute to neointimal hyperplasia after vascular injury. Our findings provide insight into the Nrf2 system as a novel therapeutic target for vascular remodeling and atherosclerosis.
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Affiliation(s)
- Takashi Ashino
- Division of Toxicology, Department of Pharmacology, Toxicology and Therapeutics, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
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22
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Kador PF, Zhang P, Makita J, Zhang Z, Guo C, Randazzo J, Kawada H, Haider N, Blessing K. Novel diabetic mouse models as tools for investigating diabetic retinopathy. PLoS One 2012; 7:e49422. [PMID: 23251343 PMCID: PMC3520987 DOI: 10.1371/journal.pone.0049422] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 10/07/2012] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVE Mouse models possessing green fluorescent protein (GFP) and/or human aldose reductase (hAR) in vascular tissues have been established and crossed with naturally diabetic Akita mice to produce new diabetic mouse models. RESEARCH DESIGN AND METHODS Colonies of transgenic C57BL mice expressing GFP (SMAA-GFP), hAR (SMAA-hAR) or both (SMAA-GFP-hAR) in vascular tissues expressing smooth muscle actin were established and crossbred with C57BL/6-Ins2(Akita)/J (AK) mice to produce naturally diabetic offspring AK-SMAA-GFP and AK-SMAA-GFP-hAR. Aldose reductase inhibitor AL1576 (ARI) was administered in chow. Retinal and lenticular sorbitol levels were determined by HPLC. Retinal functions were evaluated by electroretinography (ERGs). Growth factor and signaling changes were determined by Western Blots using commercially available antibodies. Retinal vasculatures were isolated from the neural retina by enzymatic digestion. Flat mounts were stained with PAS-hematoxylin and analyzed. RESULTS Akita transgenics developed DM by 8 weeks of age with blood glucose levels higher in males than females. Sorbitol levels were higher in neural retinas of AK-SMAA-GFP-hAR compared to AK-SMAA-GFP mice. AK-SMAA-GFP-hAR mice also had higher VEGF levels and reduced ERG scotopic b-wave function, both of which were normalized by AL1576. AK-SMAA-GFP-hAR mice showed induction of the retinal growth factors bFGF, IGF-1, and TGFβ, as well as signaling changes in P-Akt, P-SAPK/JNK and P-44/42 MAPK that were also reduced by ARI treatment. Quantitative analysis of flat mounts in 18 week AK-SMAA-GFP-hAR mice revealed increased loss of nuclei/capillary length and a significant increase in the percentage of acellular capillaries present which was not seen in AK-SMAA-GFP-hAR treated with ARI. CONCLUSIONS/SIGNIFICANCE These new mouse models of early onset diabetes may be valuable tools for assessing both the role of hyperglycemia and AR in the development of retinal lesions associated with diabetic retinopathy.
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Affiliation(s)
- Peter F Kador
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
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MicroRNA-30b-mediated regulation of catalase expression in human ARPE-19 cells. PLoS One 2012; 7:e42542. [PMID: 22880027 PMCID: PMC3412823 DOI: 10.1371/journal.pone.0042542] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 07/09/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Oxidative injury to retinal pigment epithelium (RPE) and retinal photoreceptors has been linked to a number of retinal diseases, including age-related macular degeneration (AMD). Reactive oxygen species (ROS)-mediated gene expression has been extensively studied at transcriptional levels. Also, the post-transcriptional control of gene expression at the level of translational regulation has been recently reported. However, the microRNA (miRNA/miR)-mediated post-transcriptional regulation in human RPE cells has not been thoroughly looked at. Increasing evidence points to a potential role of miRNAs in diverse physiological processes. METHODOLOGY/PRINCIPAL FINDINGS We demonstrated for the first time in a human retinal pigment epithelial cell line (ARPE-19) that the post-transcriptional control of gene expression via miRNA modulation regulates human catalase, an important and potent component of cell's antioxidant defensive network, which detoxifies hydrogen peroxide (H(2)O(2)) radicals. Exposure to several stress-inducing agents including H(2)O(2) has been reported to alter miRNA expression profile. Here, we demonstrated that a sublethal dose of H(2)O(2) (200 µM) up-regulated the expression of miR-30b, a member of the miR-30 family, which inhibited the expression of endogenous catalase both at the transcript and protein levels. However, antisense (antagomirs) of miR-30b was not only found to suppress the miR-30b mimics-mediated inhibitions, but also to dramatically increase the expression of catalase even under an oxidant environment. CONCLUSIONS/SIGNIFICANCE We propose that a microRNA antisense approach could enhance cytoprotective mechanisms against oxidative stress by increasing the antioxidant defense system.
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Mo C, Dai Y, Kang N, Cui L, He W. Ectopic expression of human MutS homologue 2 on renal carcinoma cells is induced by oxidative stress with interleukin-18 promotion via p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) signaling pathways. J Biol Chem 2012; 287:19242-54. [PMID: 22493490 DOI: 10.1074/jbc.m112.349936] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human MutS homologue 2 (hMSH2), a crucial element of the highly conserved DNA mismatch repair system, maintains genetic stability in the nucleus of normal cells. Our previous studies indicate that hMSH2 is ectopically expressed on the surface of epithelial tumor cells and recognized by both T cell receptor γδ (TCRγδ) and natural killer group 2 member D (NKG2D) on Vδ2 T cells. Ectopically expressed hMSH2 could trigger a γδ T cell-mediated cytolysis. In this study, we showed that oxidative stress induced ectopic expression of hMSH2 on human renal carcinoma cells. Under oxidative stress, both p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) pathways have been confirmed to mediate the ectopic expression of hMSH2 through the apoptosis-signaling kinase 1 (ASK1) upstream and activating transcription factor 3 (ATF3) downstream of both pathways. Moreover, renal carcinoma cell-derived interleukin (IL)-18 in oxidative stress was a prominent stimulator for ectopically induced expression of hMSH2, which was promoted by interferon (IFN)-γ as well. Finally, oxidative stress or pretreatment with IL-18 and IFN-γ enhanced γδ T cell-mediated cytolysis of renal carcinoma cells. Our results not only establish a mechanism of ectopic hMSH2 expression in tumor cells but also find a biological linkage between ectopic expression of hMSH2 and activation of γδ T cells in stressful conditions. Because γδ T cells play an important role in the early stage of innate anti-tumor response, γδ T cell activation triggered by ectopically expressed hMSH2 may be an important event in immunosurveillance for carcinogenesis.
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Affiliation(s)
- Chen Mo
- Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Peking Union Medical College, Beijing 100005, China
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25
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Nagase M, Ayuzawa N, Kawarazaki W, Ishizawa K, Ueda K, Yoshida S, Fujita T. Oxidative Stress Causes Mineralocorticoid Receptor Activation in Rat Cardiomyocytes. Hypertension 2012; 59:500-6. [DOI: 10.1161/hypertensionaha.111.185520] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Miki Nagase
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Nobuhiro Ayuzawa
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Wakako Kawarazaki
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Kenichi Ishizawa
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Kohei Ueda
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Shigetaka Yoshida
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Toshiro Fujita
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
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26
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Qian J, Keyes KT, Long B, Chen G, Ye Y. Impact of HMG-CoA reductase inhibition on oxidant-induced injury in human retinal pigment epithelium cells. J Cell Biochem 2011; 112:2480-9. [DOI: 10.1002/jcb.23173] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Choi SH, Park SJ, Cha GH, Quan JH, Chang NS, Ahn MH, Shin DW, Lee YH. Toxoplasma gondii protects against H(2)O(2) -induced apoptosis in ARPE-19 cells through the transcriptional regulation of apoptotic elements and downregulation of the p38 MAPK pathway. Acta Ophthalmol 2011; 89:e350-6. [PMID: 21385331 DOI: 10.1111/j.1755-3768.2011.02113.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Toxoplasmosis, which is caused by the protozoan parasite Toxoplasma gondii, can lead to severe visual impairment. T. gondii inhibits or delays programmed cell death caused by various apoptotic triggers; however, the mechanisms involved in the T. gondii-induced suppression of apoptosis in retinal cells have not been analysed in detail. METHODS We investigated the role of T. gondii infection in H(2)O(2) -induced apoptosis in human retinal pigment epithelial cells (ARPE-19) by monitoring the activities of apoptosis-regulating molecules and mitogen-activated protein kinases (MAPKs), including p38 MAPK. We also examined the gene downstream from p38 MAPK. RESULTS T. gondii infection significantly inhibited the cellular toxicity of H(2)O(2) (500 μm) and increased cell viability in a multiplicity of infection (MOI)-dependent manner by reducing DNA fragmentation and reactive oxygen species (ROS) generation in ARPE-19 cells. Western blot analysis also showed that T. gondii infection prevented the host cell expression of pro-apoptotic factors, such as Bad and Bax, and the activation of caspase-3. Infection with T. gondii increased the expression of the anti-apoptotic factor Bcl-2 in ARPE-19 cells under oxidative stress. In accordance with these findings, Toxoplasma infection was protective enough to suppress the phosphorylation of p38 MAPK following H(2)O(2) treatment. Exposure to H(2)O(2) increased the expression of heme oxygenase-1 (HO-1) in ARPE-19 cells, and its expression was significantly inhibited in H(2)O(2) -treated infected cells. CONCLUSION The protective function of T. gondii infection against ROS-induced apoptosis results from changes in the expression of apoptotic molecules and the downregulation of stress-induced intracellular signalling.
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Affiliation(s)
- Si-Hwan Choi
- Department of Ophthalmology, Chungnam National University School of Medicine, Daejeon, Korea
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Heo J. Redox control of GTPases: from molecular mechanisms to functional significance in health and disease. Antioxid Redox Signal 2011; 14:689-724. [PMID: 20649471 DOI: 10.1089/ars.2009.2984] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Small GTPases, including the proto-oncoprotein Ras and Rho GTPases, are involved in various cellular signaling events. Some of these small GTPases are redox sensitive, including Ras, Rho, Ran, Dexras1, and Rhes GTPases. Thus, the redox-mediated regulation of these GTPases often determines the course of their cellular signaling cascades. This article takes into consideration the application of Marcus theory to potential redox-based molecular mechanisms in the regulation of these redox-sensitive GTPases and the relevance of such mechanisms to a specific redox-sensitive motif. The discussion also takes into account various diseases, including cancers, heart, and neuronal disorders, that are often linked with the dysregulation of the redox signaling cascades associated with these redox-sensitive GTPases.
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Affiliation(s)
- Jongyun Heo
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA.
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Klettner A, Koinzer S, Waetzig V, Herdegen T, Roider J. Deferoxamine mesylate is toxic for retinal pigment epithelium cellsin vitro, and its toxicity is mediated by p38. Cutan Ocul Toxicol 2010; 29:122-9. [DOI: 10.3109/15569521003745685] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kim NH, Oh MK, Park HJ, Kim IS. Auranofin, a Gold(I)-Containing Antirheumatic Compound, Activates Keap1/Nrf2 Signaling via Rac1/iNOS Signal and Mitogen-Activated Protein Kinase Activation. J Pharmacol Sci 2010; 113:246-54. [DOI: 10.1254/jphs.09330fp] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Son YO, Jang YS, Shi X, Lee JC. Activation of JNK and c-Jun is involved in glucose oxidase-mediated cell death of human lymphoma cells. Mol Cells 2009; 28:545-51. [PMID: 19937141 DOI: 10.1007/s10059-009-0149-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 09/09/2009] [Accepted: 09/17/2009] [Indexed: 12/29/2022] Open
Abstract
Mitogen-activated protein kinases (MAPK) affect the activation of activator protein-1 (AP-1), which plays an important role in regulating a range of cellular processes. However, the roles of these signaling factors on hydrogen peroxide (H(2)O(2))-induced cell death are unclear. This study examined the effects of H(2)O(2) on the activation of MAPK and AP-1 by exposing the cells to H(2)O(2) generated by either glucose oxidase or a bolus addition. Exposing BJAB or Jurkat cells to H(2)O(2) affected the activities of MAPK differently according to the method of H(2)O(2) exposure. H(2)O(2) increased the AP-1-DNA binding activity in these cells, where continuously generated H(2)O(2) led to an increase in mainly the c-Fos, FosB and c-Jun proteins. The c-Jun-NH(2)-terminal kinase (JNK)-mediated activation of c-Jun was shown to be related to the H(2)O(2)-induced cell death. However, the suppression of H(2)O(2)-induced oxidative stress by either JNK inhibitor or c-Jun specific antisense transfection was temporary in the cells exposed to glucose oxidase but not to a bolus H(2)O(2). This was associated with the disruption of death signaling according to the severe and prolonged depletion of reduced glutathione. Overall, these results suggest that H(2)O(2) may decide differently the mode of cell death by affecting the intracellular redox state of thiol-containing antioxidants, and this depends more closely on the duration exposed to H(2)O(2) than the concentration of this agent.
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Affiliation(s)
- Young-Ok Son
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536-0001, USA
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Kalariya NM, Wills NK, Ramana KV, Srivastava SK, van Kuijk FJ. Cadmium-induced apoptotic death of human retinal pigment epithelial cells is mediated by MAPK pathway. Exp Eye Res 2009; 89:494-502. [DOI: 10.1016/j.exer.2009.05.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 05/06/2009] [Accepted: 05/12/2009] [Indexed: 01/14/2023]
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Pocrnich CE, Liu H, Feng M, Peng T, Feng Q, Hutnik CM. p38 mitogen-activated protein kinase protects human retinal pigment epithelial cells exposed to oxidative stress. Can J Ophthalmol 2009; 44:431-6. [DOI: 10.3129/i09-109] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Apoptosis-inducing factor plays a critical role in caspase-independent, pyknotic cell death in hydrogen peroxide-exposed cells. Apoptosis 2009; 14:796-808. [PMID: 19418225 DOI: 10.1007/s10495-009-0353-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
It has been proposed that continuously generated hydrogen peroxide (H(2)O(2)) inhibits typical apoptosis and instead initiates an alternate, apoptosis-inducing factor (AIF)-dependent process. Aside from the role of AIF, however, the detailed morphological characterization of H(2)O(2)-induced cell death is not complete. This study examined the cellular mechanism(s) by which the continuous presence of H(2)O(2) induces cell death. We also further analyzed the precise role of AIF by inhibiting its expression with siRNA. Exposure of cells to H(2)O(2) generated by glucose oxidase caused mitochondrion-mediated, caspase-independent cell death. In addition, H(2)O(2) exposure resulted in cell shrinkage and chromatin condensation without nuclear fragmentation, indicating that H(2)O(2) stimulates a pyknotic cell death. Further analysis of AIF-transfected cells clearly demonstrated that nuclear translocation of AIF is the most important event required for nuclear condensation, phosphatidyl serine translocation, and ultimately cell death in H(2)O(2)-exposed cells. Furthermore, ATP was rapidly and severely depleted in cells exposed to H(2)O(2) generated by glucose oxidase but not by H(2)O(2) added as a bolus. Suppression of the H(2)O(2)-mediated ATP depletion by 3-aminobenzamide led to a significant increase of nuclear fragmentation in glucose oxidase-exposed cells. Collectively, these findings suggest that an acute energy reduction by H(2)O(2) causes caspase-independent and AIF-dependent cell death.
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Wang ZY, Shen LJ, Tu L, Hu DN, Liu GY, Zhou ZL, Lin Y, Chen LH, Qu J. Erythropoietin protects retinal pigment epithelial cells from oxidative damage. Free Radic Biol Med 2009; 46:1032-41. [PMID: 19136057 DOI: 10.1016/j.freeradbiomed.2008.11.027] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 10/10/2008] [Accepted: 11/18/2008] [Indexed: 12/17/2022]
Abstract
Oxidative damage from reactive oxygen species (ROS) has been implicated in many diseases, including age-related macular degeneration, in which the retinal pigment epithelium (RPE) is considered a primary target. The aim of this study was to determine whether erythropoietin (EPO) protects cultured human RPE cells against oxidative damage and to identify the pathways that may mediate protection. EPO (1 IU/ml) significantly increased the viability of oxidant-treated RPE cells, decreased the release of the inflammatory cytokines tumor necrosis factor-alpha and interleukin-1beta, recovered the RPE cells' barrier integrity disrupted by oxidative stress, prevented oxidant-induced cell DNA fragmentation and membrane phosphatidylserine exposure, and also reduced the levels of oxidant-induced intracellular ROS and restored cellular antioxidant potential, total antioxidant capacity, glutathione peroxidase, and superoxide dismutase and decreased malondialdehyde, the end product of lipid peroxidation. EPO inhibited caspase-3-like activity. Protection by EPO was partly dependent on the activation of Akt1 and the maintenance of the mitochondrial membrane potential. No enhanced or synergistic protection was observed during application of Z-DEVD-FMK (caspase-3 inhibitor) combined with EPO compared with cultures exposed to EPO and H(2)O(2) alone. Together, these results suggest that EPO could protect against oxidative injury-induced cell death and mitochondrial dysfunction in RPE cells through modulation of Akt1 phosphorylation, mitochondrial membrane potential, and cysteine protease activity.
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Affiliation(s)
- Zhao-yang Wang
- The School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
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36
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Westlund BS, Cai B, Zhou J, Sparrow JR. Involvement of c-Abl, p53 and the MAP kinase JNK in the cell death program initiated in A2E-laden ARPE-19 cells by exposure to blue light. Apoptosis 2009; 14:31-41. [PMID: 19052872 DOI: 10.1007/s10495-008-0285-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The lipofuscin fluorophore A2E has been shown to mediate blue light-induced damage to retinal pigmented epithelial (RPE) cells. To understand the events that lead to RPE cell apoptosis under these conditions, we explored signaling pathways upstream of the cell death program. Human RPE cells (ARPE-19) that had accumulated A2E were exposed to blue light to induce apoptosis and the involvement of the transcription factors p53 and c-Abl and the mitogen activated protein kinases p38 and JNK were examined. We found that A2E/blue light caused upregulation and phosphorylation of c-Abl, and upregulation of p53. Pretreatment with the c-Abl inhibitor STI571 and transfection with siRNA specific to c-Abl and p53 prior to irradiation reduced A2E/blue light-induced cell death. Gene and protein expression of JNK and p38 was upregulated in response to A2E/blue light. Treatment with the JNK inhibitor SP600125 before irradiation resulted in increase in cell death whereas inhibition of p38 with SB203580 had no effect. This study indicates that c-Abl and p53 are important for execution of the cell death program initiated in A2E-laden RPE cells exposed to blue light, while JNK might play an anti-apoptotic role.
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Affiliation(s)
- Barbro S Westlund
- Department of Ophthalmology, Columbia University, 630 W. 168th Street, New York, NY 10032, USA
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37
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Lornejad-Schäfer MR, Schäfer C, Schöffl H, Frank J. Cytoprotective role of mitogen-activated protein kinase phosphatase-1 in light-damaged human retinal pigment epithelial cells. Photochem Photobiol 2008; 85:834-42. [PMID: 19076312 DOI: 10.1111/j.1751-1097.2008.00479.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The role of the mitogen-activated protein (MAP) kinase phosphatases (MKPs) in light-damaged cells is unclear. Therefore we investigated the involvement of MKP-1 in the regulation of apoptosis and cell survival mediated by MAP kinase pathways in light-damaged human retinal pigment epithelial cells (ARPE-19). Light dose-dependent changes in the expression of MKP-1 and in the phosphorylation status of the MAP kinases, c-Jun-N-terminal kinase (JNK) and p38 were demonstrated. Low light doses up to 2 J cm(-2) led to an upregulation of MKP-1 which resulted in the prevention of cell death by inactivating JNK kinase. However, higher light doses (> or =3 J cm(-2)) significantly reduced MKP-1 protein expression and subsequently led to an increased JNK kinase activity followed by a significant increase in cell death. JNK kinase inactivation by the JNK inhibitor SP600125 significantly reduced light-induced cell death, suggesting that the cytoprotective properties of MKP-1 are mediated mainly by the JNK MAP kinase pathway. Physiological concentrations of ascorbic acid or taurine were seen to prevent apoptosis and cell death in light-damaged ARPE-19 cells by reducing oxidative stress within cells, thus maintaining MKP-1 at high levels, leading to an inactivation of the JNK kinase pathway which resulted in an increased cell viability.
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38
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Tsai RK, Chang CH, Hseu CM, Chang SM, Wu JR, Wang HZ, Wu WC, Wu WS. Ethambutol induces PKC-dependent cytotoxic and antiproliferative effects on human retinal pigment cells. Exp Eye Res 2008; 87:594-603. [PMID: 18948097 DOI: 10.1016/j.exer.2008.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 10/21/2022]
Abstract
Ethambutol (EMB)-induced ocular side effects may involve the influence on functions of retinal pigment epithelium (RPE), in addition to EMB-induced optic neuropathy. To address this issue, the molecular and cellular effects of EMB on RPE including growth regulation, morphological responses, phagocytic activity, and the relevant signaling pathways were investigated. EMB (at optimal concentration 8.0mM) can trigger cell cycle arrest in both RPE50 and ARPE19 cells, accompanied by reduced DNA synthesis. EMB also induced cytoplasmic vacuole formation in both RPE cell lines. Under transmission electric microscope, the phagosomes were replaced by vacuoles and the number of microvilli was reduced in EMB-treated cells. Animal experiments also demonstrated the vacuole formation within RPE of the EMB-treated rats. On the other hand, by in vitro phagocytosis assay using rod outer segment (ROS) as the target, we found EMB suppressed phagocytosis in the cultured RPE, which is consistent with the decreased rhodopsin uptake in the RPE of the EMB-treated rats. Furthermore, inhibitor of protein kinase C but not MAPK, prevented the EMB-induced phenotypical changes. Using a non-radioactive PKC assay, we also demonstrated the PKC activity in both RPE cell lines can be induced by EMB. In conclusion, EMB may exert toxic effects in RPE including suppression of cell growth, formation of cytoplasmic vacuoles and reduction of phagocytic functions via PKC signal pathway.
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Affiliation(s)
- Rong Kung Tsai
- Department of Ophthalmology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
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39
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40
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Roduit R, Schorderet DF. MAP kinase pathways in UV-induced apoptosis of retinal pigment epithelium ARPE19 cells. Apoptosis 2008; 13:343-53. [PMID: 18253836 DOI: 10.1007/s10495-008-0179-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The retinal pigment epithelium (RPE) is constantly exposed to external injuries which lead to degeneration, dysfunction or loss of RPE cells. The balance between RPE cells death and proliferation may be responsible for several diseases of the underlying retina, including age-related macular degeneration (AMD) and proliferative vitreoretinopathy (PVR). Signaling pathways able to control cells proliferation or death usually involve the MAPK (mitogen-activated protein kinases) pathways, which modulate the activity of transcription factors by phosphorylation. UV exposure induces DNA breakdown and causes cellular damage through the production of reactive oxygen species (ROS) leading to programmed cell death. In this study, human retinal pigment epithelial cells ARPE19 were exposed to 100 J/m(2) of UV-C and MAPK pathways were studied. We first showed the expression of the three major MAPK pathways. Then we showed that activator protein-1 (AP-1) was activated through phosphorylation of cJun and cFos, induced by JNK and p38, respectively. Specific inhibitors of both kinases decreased their respective activities and phosphorylation of their nuclear targets (cJun and cFos) and reduced UV-induced cell death. The use of specific kinases inhibitors may provide excellent tools to prevent RPE apoptosis specifically in RPE diseases involving ROS and other stress-related compounds such as in AMD.
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Affiliation(s)
- Raphaël Roduit
- IRO, Institut de Recherche en Ophtalmologie, Gd-Champsec 64, 1950, Sion, Switzerland.
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41
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Actis-Goretta L, Romanczyk LJ, Rodriguez CA, Kwik-Uribe C, Keen CL. Cytotoxic effects of digalloyl dimer procyanidins in human cancer cell lines. J Nutr Biochem 2008; 19:797-808. [PMID: 18440795 DOI: 10.1016/j.jnutbio.2007.10.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 09/30/2007] [Accepted: 10/29/2007] [Indexed: 10/22/2022]
Abstract
Flavanols, a class of polyphenols present in certain plant-based foods, have received increasing attention for their putative anticancer activity. In vitro and in vivo studies, which have compared the effectiveness of various monomer flavanols, indicate that the presence of a galloyl residue on the 3 position on the C-ring enhances the cytotoxicity of these compounds. Procyanidins, oligomerized flavanols, have been reported to be more cytotoxic than monomer flavanols in a variety of human cancer cell lines. Given the above, we evaluated the potential anticancer properties of dimer procyanidins that contain galloyl groups. Specifically, the cytotoxicity of synthetic digalloyl dimer B1 and B2 esters {[3-O-galloyl]-(-)-epicatechin-(4beta,8)-(+)-catechin-3-O-gallate (DGB1) and [3-O-galloyl]-(-)-epicatechin-(4beta,8)-(+)-epicatechin-3-O-gallate (DGB2), respectively} were tested in a number of in vitro models. DGB1 produced significant cytotoxicity in a number of human cancer cell lines evaluated by three independent methods: ATP content, MTT and MTS assays. For the three most sensitive cell lines, exposure to DGB1 and DGB2 for 24, 48 or 72 h was associated with a reduction in cell number and an inhibition of cell proliferation. Digalloyl dimers exerted significantly higher cytotoxic effects than the structurally related flavanols, (-)-epicatechin, (+)-catechin, (-)-epicatechin gallate, (-)-epigallocatechin gallate, (-)-catechin gallate and dimer B1 and B2. These results support the concept that the incorporation of galloyl groups and the oligomerization of flavanols enhances the cytotoxic effects of typical monomer flavanols. The therapeutic value of these compounds and their derivative forms as anticancer agents merits further investigation in whole animal models.
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Ethier C, Labelle Y, Poirier GG. PARP-1-induced cell death through inhibition of the MEK/ERK pathway in MNNG-treated HeLa cells. Apoptosis 2007; 12:2037-49. [PMID: 17828454 DOI: 10.1007/s10495-007-0127-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Poly(ADP-ribose) polymerase-1 (PARP-1) hyper-activation promotes cell death but the signaling events downstream of PARP-1 activation are not fully identified. To gain further information on the implication of PARP-1 activation and PAR synthesis on signaling pathways influencing cell death, we exposed HeLa cells to the DNA alkylating agent N-methyl-N'-methyl-nitro-N-nitrosoguanidine (MNNG). We found that massive PAR synthesis leads to down-regulation of ERK1/2 phosphorylation, Bax translocation to the mitochondria, release of cytochrome c and AIF and subsequently cell death. Inhibition of massive PAR synthesis following MNNG exposure with the PARP inhibitor PJ34 prevented those events leading to cell survival, whereas inhibition of ERK1/2 phosphorylation by inhibiting MEK counteracted the cytoprotective effect of PJ34. Together, our results provide evidence that PARP-1-induced cell death by MNNG exposure in HeLa cells is mediated in part through inhibition of the MEK/ERK signaling pathway and that inhibition of massive PAR synthesis by PJ34, which promotes sustained activation of ERK1/2, leads to cytoprotection.
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Affiliation(s)
- Chantal Ethier
- Health and Environment Unit, Laval University Medical Research Center, CHUQ, Faculty of Medicine, Laval University, 2705, Boulevard Laurier, Quebec City, QC, Canada G1V 4G2
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Zhang Y, Venugopal SK, He S, Liu P, Wu J, Zern MA. Ethanol induces apoptosis in hepatocytes by a pathway involving novel protein kinase C isoforms. Cell Signal 2007; 19:2339-50. [PMID: 17728104 DOI: 10.1016/j.cellsig.2007.07.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 07/11/2007] [Accepted: 07/18/2007] [Indexed: 11/29/2022]
Abstract
UNLABELLED Ethanol abuse is one of the major etiologies of cirrhosis. Ethanol has been shown to induce apoptosis via activation of oxidative stress, mitogen-activated protein kinases (MAPK), and tyrosine kinases. However, there is a paucity of data that examine the interplay among these molecules. In the present study we have systematically elucidated the role of novel protein kinase C isoforms (nPKC; PKCdelta and PKCepsilon) in ethanol-induced apoptosis in hepatocytes. Ethanol enhanced membrane translocation of PKCdelta and PKCepsilon, which was associated with the phosphorylation of p38MAPK, p42/44MAPK and JNK1/2, and the nuclear translocation of NF-kappaB and AP-1. This resulted in increased apoptosis in primary rat hepatocytes. Inhibition of both PKCdelta and PKCepsilon resulted in a decreased MAPK activation, decreased nuclear translocation of NF-kappaB and AP-1, and inhibition of apoptosis. In addition, ethanol activated the tyrosine phosphorylation of PKCdelta via tyrosine kinase in hepatocytes. The tyrosine phosphorylated PKCdelta was cleaved by caspase-3 and these fragments were translocated to the nucleus. Inhibition of ethanol-induced oxidative stress blocked the membrane translocation of PKCdelta and PKCepsilon, and the tyrosine phosphorylation of PKCdelta in hepatocytes. Inhibition of oxidative stress, tyrosine kinase or caspase-3 activity caused a decreased nuclear translocation of PKCdelta in response to ethanol, and was associated with less apoptosis. CONCLUSION These results provide a newly-described mechanism by which ethanol induces apoptosis via activation of nPKC isoforms in hepatocytes.
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Affiliation(s)
- Yanhong Zhang
- Department of Internal Medicine, Transplant Research Program, University of California, Davis Medical Center, Sacramento, CA 95817, USA
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Zhang L, Li L, Liu H, Prabhakaran K, Zhang X, Borowitz JL, Isom GE. HIF-1alpha activation by a redox-sensitive pathway mediates cyanide-induced BNIP3 upregulation and mitochondrial-dependent cell death. Free Radic Biol Med 2007; 43:117-27. [PMID: 17561100 PMCID: PMC2048659 DOI: 10.1016/j.freeradbiomed.2007.04.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 04/02/2007] [Accepted: 04/02/2007] [Indexed: 12/21/2022]
Abstract
Cyanide produces degeneration of the nervous system in which different modes of cell death are activated in the vulnerable brain areas. In brain, the mechanism underlying the cell death is not clear. In this study, an immortalized dopaminergic cell line was used to characterize the cell death signaling cascade activated by cyanide. Cyanide-treated cells exhibited a time- and concentration-dependent apoptosis that was caspase independent. Cyanide induced a rapid surge of intracellular reactive oxygen species (ROS) generation, followed by p38 mitogen-activated protein kinase (MAPK) activation and nuclear accumulation of hypoxia-inducible factor-1alpha (HIF-1alpha). Activation of p38 MAPK and HIF-1alpha accumulation were attenuated by N-acetyl-L-cysteine (antioxidant), catalase (hydrogen peroxide scavenger), or a selective p38 MAPK inhibitor (SB203580). Cyanide activated the hypoxia response element (HRE) promoter, which was also blocked by the antioxidants and SB203580. HRE activation was followed by increased BNIP3 gene transcription, as reflected by elevated BNIP3 mRNA and protein levels. BNIP3 upregulation was reduced by selective RNAi knockdown of HIF-1alpha. Overexpression of BNIP3 produced mitochondrial dysfunction (reduced membrane potential), caspase-independent apoptosis, and sensitization of the cells to cyanide-induced toxicity. Expression of a dominant-negative mutant or RNAi knockdown of BNIP3 protected the cells from cyanide. It was concluded that cyanide activated the HIF-1alpha-mediated pathway of BNIP3 induction through a redox-sensitive process. Increased BNIP3 expression then served as an initiator of mitochondrial-mediated death.
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Affiliation(s)
- L Zhang
- Department of Medicinal Chemistry & Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA
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