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Li S, Chen J, Xie P, Guo X, Fan H, Yu D, Zeng C, Chen L. The role of glutathione detoxification pathway in MCLR-induced hepatotoxicity in SD rats. Environ Toxicol 2015; 30:1470-80. [PMID: 24964298 DOI: 10.1002/tox.22017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 06/13/2014] [Accepted: 06/15/2014] [Indexed: 05/18/2023]
Abstract
In the present study, we investigated the role of glutathione (GSH) and its related enzymes in Sprague Dawley (SD) rats subjected to microcystin-leucine-arginine (MCLR)-induced hepatotoxicity. SD rats were intraperitoneally (i.p.) injected with MCLR after pretreating with or without buthionine-(S,R)-sulfoximine (BSO), an inhibitor of GSH synthesis. The depletion of GSH with BSO enhanced MCLR-induced oxidative stress, resulting in more severe liver damage and higher MCLR accumulation. Similarly, the contents of malondialdehyde (MDA), total GSH (T-GSH), oxidized GSH (GSSG) and GSH were significantly enhanced in BSO pretreated rats following MCLR treatment. The study showed that the transcription of GSH-related enzymes such as glutathione-S-transferase (GST), γ-glutamylcysteine synthetase (γ-GCS), glutathione reductase (GR) varied in different ways (expect for glutathione peroxidase (GPx), whose gene expression was induced in all treated groups) with or without BSO pretreatment before MCLR exposure, suggesting an adaptative response of GSH-related enzymes at transcription level to combat enhancement of oxidative stress induced by MCLR when pretreated with BSO. These data suggested the tissues with low GSH concentration are highly vulnerable to MCLR toxicity and GSH was critical for the detoxification in MCLR-induced hepatotoxicity in vivo.
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Affiliation(s)
- Shangchun Li
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Jun Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Ping Xie
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Xiaochun Guo
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- Fisheries College, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Huihui Fan
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- Fisheries College, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Dezhao Yu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Cheng Zeng
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- Fisheries College, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Liang Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
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Shanmugam V, Wang YW, Tsednee M, Karunakaran K, Yeh KC. Glutathione plays an essential role in nitric oxide-mediated iron-deficiency signaling and iron-deficiency tolerance in Arabidopsis. Plant J 2015; 84:464-77. [PMID: 26333047 DOI: 10.1111/tpj.13011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/17/2015] [Accepted: 08/25/2015] [Indexed: 05/18/2023]
Abstract
Iron (Fe) deficiency is a common agricultural problem that affects both the productivity and nutritional quality of plants. Thus, identifying the key factors involved in the tolerance of Fe deficiency is important. In the present study, the zir1 mutant, which is glutathione deficient, was found to be more sensitive to Fe deficiency than the wild type, and grew poorly in alkaline soil. Other glutathione-deficient mutants also showed various degrees of sensitivity to Fe-limited conditions. Interestingly, we found that the glutathione level was increased under Fe deficiency in the wild type. By contrast, blocking glutathione biosynthesis led to increased physiological sensitivity to Fe deficiency. On the other hand, overexpressing glutathione enhanced the tolerance to Fe deficiency. Under Fe-limited conditions, glutathione-deficient mutants, zir1, pad2 and cad2 accumulated lower levels of Fe than the wild type. The key genes involved in Fe uptake, including IRT1, FRO2 and FIT, are expressed at low levels in zir1; however, a split-root experiment suggested that the systemic signals that govern the expression of Fe uptake-related genes are still active in zir1. Furthermore, we found that zir1 had a lower accumulation of nitric oxide (NO) and NO reservoir S-nitrosoglutathione (GSNO). Although NO is a signaling molecule involved in the induction of Fe uptake-related genes during Fe deficiency, the NO-mediated induction of Fe-uptake genes is dependent on glutathione supply in the zir1 mutant. These results provide direct evidence that glutathione plays an essential role in Fe-deficiency tolerance and NO-mediated Fe-deficiency signaling in Arabidopsis.
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Affiliation(s)
| | - Yi-Wen Wang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Munkhtsetseg Tsednee
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Krithika Karunakaran
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Kuo-Chen Yeh
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
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Abstract
Knowledge of arsenic (As) accumulation in rice (Oryza sativa L.) is important for minimizing As transfer to the food chain. The aim of this study was to investigate the role of rice nodes in As storage and distribution. Synchrotron μX-ray fluorescence (μ-XRF) was used to map As distribution in the top node and internode of a lsi2 mutant defective in silicon/arsenite efflux carrier and its wild-type (WT) grown in soil. Lsi2 expression in different tissues during grain filling was investigated by quantitative RT-PCR. Arsenite or dimethylarsinic acid (DMA) was supplied to excised panicles to investigate the roles of Lsi2 and phytochelatins (PC) in As distribution. μ-XRF mapping revealed As storage in the phloem of different vascular bundles in the top node and internode. Soil-grown plants of lsi2 had markedly decreased As accumulation in the phloem compared with the WT. Lsi2 was strongly expressed, not only in the roots but also in the nodes. When excised panicles were exposed to As(III), the lsi2 mutant distributed more As to the node and flag leaf but less As to the grain compared with the WT, while there was no significant difference in DMA distribution. Inhibition of PC synthesis by l-buthionine-sulphoximine decreased As(III) deposition in the top node but increased As accumulation in the grain and flag leaf. The results suggest that rice nodes serve as a filter restricting As(III) distribution to the grain. Furthermore, Lsi2 plays a role in As(III) distribution in rice nodes and phytochelatins are important compounds for As(III) storage in the nodes.
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Affiliation(s)
- Yi Chen
- Department of Sustainable Soils and Grassland Systems, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Katie L Moore
- School of Materials, University of Manchester, Manchester M13 9PL, UK
| | - Anthony J Miller
- Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Steve P McGrath
- Department of Sustainable Soils and Grassland Systems, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Jian Feng Ma
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki 710-0046, Japan
| | - Fang-Jie Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
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Brunetti P, Zanella L, De Paolis A, Di Litta D, Cecchetti V, Falasca G, Barbieri M, Altamura MM, Costantino P, Cardarelli M. Cadmium-inducible expression of the ABC-type transporter AtABCC3 increases phytochelatin-mediated cadmium tolerance in Arabidopsis. J Exp Bot 2015; 66:3815-29. [PMID: 25900618 PMCID: PMC4473984 DOI: 10.1093/jxb/erv185] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The heavy metal cadmium (Cd) is a widespread environmental contaminant with harmful effects on living cells. In plants, phytochelatin (PC)-dependent Cd detoxification requires that PC-Cd complexes are transported into vacuoles. Here, it is shown that Arabidopsis thaliana seedlings defective in the ABCC transporter AtABCC3 (abcc3) have an increased sensitivity to different Cd concentrations, and that seedlings overexpressing AtABCC3 (AtABCC3ox) have an increased Cd tolerance. The cellular distribution of Cd was analysed in protoplasts from abcc3 mutants and AtABCC3 overexpressors grown in the presence of Cd, by means of the Cd-specific fluorochromes 5-nitrobenzothiazole coumarin (BTC-5N) and Leadmium™ Green AM dye. This analysis revealed that Cd is mostly localized in the cytosol of abcc3 mutant protoplasts whereas there is an increase in vacuolar Cd in protoplasts from AtABCC3ox plants. Overexpression of AtABCC3 in cad1-3 mutant seedlings defective in PC production and in plants treated with l-buthionine sulphoximine (BSO), an inhibitor of PC biosynthesis, had no effect on Cd tolerance, suggesting that AtABCC3 acts via PCs. In addition, overexpression of AtABCC3 in atabcc1 atabcc2 mutant seedlings defective in the Cd transporters AtABCC1 and AtABCC2 complements the Cd sensitivity of double mutants, but not in the presence of BSO. Accordingly, the level of AtABCC3 transcript in wild type seedlings was lower than that of AtABCC1 and AtABCC2 in the absence of Cd but higher after Cd exposure, and even higher in atabcc1 atabcc2 mutants. The results point to AtABCC3 as a transporter of PC-Cd complexes, and suggest that its activity is regulated by Cd and is co-ordinated with the activity of AtABCC1/AtABCC2.
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Affiliation(s)
- Patrizia Brunetti
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Rome, Italy
| | - Letizia Zanella
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Rome, Italy
| | - Angelo De Paolis
- Istituto di Scienze delle Produzioni Alimentari, CNR, Lecce, Italy
| | - Davide Di Litta
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy
| | - Valentina Cecchetti
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Rome, Italy
| | - Giuseppina Falasca
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Rome, Italy
| | - Maurizio Barbieri
- Dipartimento di Scienze della Terra, Sapienza Università di Roma, Rome, Italy
| | | | - Paolo Costantino
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Rome, Italy
| | - Maura Cardarelli
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy
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Wójcik M, Dresler S, Plak A, Tukiendorf A. Naturally evolved enhanced Cd tolerance of Dianthus carthusianorum L. is not related to accumulation of thiol peptides and organic acids. Environ Sci Pollut Res Int 2015; 22:7906-17. [PMID: 25510617 PMCID: PMC4432087 DOI: 10.1007/s11356-014-3963-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 12/05/2014] [Indexed: 05/20/2023]
Abstract
Two contrasting ecotypes of Dianthus carthusianorum L., metallicolous (M) and nonmetallicolous (NM), were cultivated in hydroponics at 0-50 μM Cd for 14 days to compare their Cd accumulation, sensitivity and tolerance mechanisms. While both ecotypes contained similar concentrations of Cd in the shoots and roots, the M ecotype was more Cd-tolerant (as measured by fresh weight production and root and leaf viability). Both ecotypes accumulated phytochelatins (PCs) in response to Cd with a higher amount thereof found in the NM ecotype. Concentrations of PCs remained unchanged with increasing Cd concentrations in the root tissues, but their content in the shoots increased. The addition of L-buthionine-sulfoximine (BSO) diminished glutathione (GSH) accumulation and arrested PC production, which increased the sensitivity to Cd of the NM, but not M ecotype. Organic acids (malate and citrate) as well as proline accumulation did not change significantly after Cd exposition and was at the same level in both ecotypes. The enhanced Cd tolerance of the M ecotype of D. carthusianorum cannot be explained in terms of restricted Cd uptake and differential production of PCs, organic acids or proline; some other mechanisms must be involved in its adaptation to the high Cd content in the environment.
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Affiliation(s)
- Małgorzata Wójcik
- Department of Plant Physiology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland,
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Wang X, Jiang L, Ge L, Chen M, Yang G, Ji F, Zhong L, Guan Y, Liu X. Oxidative DNA damage induced by di-(2-ethylhexyl) phthalate in HEK-293 cell line. Environ Toxicol Pharmacol 2015; 39:1099-1106. [PMID: 25899473 DOI: 10.1016/j.etap.2015.03.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 03/20/2015] [Accepted: 03/24/2015] [Indexed: 06/04/2023]
Abstract
Di-(2-ethylhexyl) phthalate (DEHP) is commonly employed as a plasticizer. We have found that exposure of human embryonic kidney cell line 293 (HEK-293) to DEHP resulted in a crucial dose-dependent increase of DNA strand breaks in a comet assay. To elucidate the role of glutathione (GSH) in the DNA damage, the cells were pretreated with buthionine-(S,R)-sulfoximine (BSO) and pretreated with N-acetylcysteine (NAC), a GSH precursor. Here we show that depletion of GSH in HEK-293 cells with BSO dramatically increased the susceptibility of HEK-293 cells to DEHP-induced DNA damage. Furthermore, when the intracellular GSH content was elevated by NAC, the DNA damage induced by DEHP was almost completely abolished. In addition, DEHP had effect on lysosomal or mitochondrial damage at high dose level. These results indicate that DEHP exerts genotoxic effects in HEK-293 cells, probably through DNA damage induced by oxidative stress; GSH is responsible for cellular defense against DEHP-induced DNA damage; lysosome and mitochondria may be the vital targets in DEHP-induced DNA damage.
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Affiliation(s)
- Xuan Wang
- Department of Nutrition and Food Safety, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China; Natural Products Engineering Technology Center, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China
| | - Lijie Jiang
- Department of Internal Medicine, The Affiliated Zhong Shan Hospital of Dalian University, Dalian, 116001 Liaoning, PR China
| | - Lan Ge
- Department of Pharmacy, Affiliated Hospital to Changchun University of Chinese Medicine, No. 1478 of Gongnong Road, Changchun, 130021 Jilin, PR China
| | - Min Chen
- Department of Nutrition and Food Safety, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China
| | - Guang Yang
- Department of Nutrition and Food Safety, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China
| | - Fang Ji
- Department of Nutrition and Food Safety, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China
| | - Laifu Zhong
- China-Japanese Joint Institute for Medical and Pharmaceutical Science, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China; Natural Products Engineering Technology Center, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China
| | - Yingjie Guan
- Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI 02903, USA
| | - Xiaofang Liu
- Department of Nutrition and Food Safety, Dalian Medical University, No. 9, West Segment of South lvshun Road, Dalian, 116044 Liaoning, PR China.
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Abdelhamid G, El-Kadi AOS. Buthionine sulfoximine, an inhibitor of glutathione biosynthesis, induces expression of soluble epoxide hydrolase and markers of cellular hypertrophy in a rat cardiomyoblast cell line: roles of the NF-κB and MAPK signaling pathways. Free Radic Biol Med 2015; 82:1-12. [PMID: 25614461 DOI: 10.1016/j.freeradbiomed.2015.01.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 01/09/2015] [Accepted: 01/10/2015] [Indexed: 01/04/2023]
Abstract
Evidence suggests that upregulation of soluble epoxide hydrolase (sEH) is associated with the development of myocardial infarction, dilated cardiomyopathy, cardiac hypertrophy, and heart failure. However, the upregulation mechanism is still unknown. In this study, we treated H9C2 cells with buthionine sulfoximine (BSO) to explore whether oxidative stress upregulates sEH gene expression and to identify the molecular and cellular mechanisms behind this upregulatory response. Real-time PCR and Western blot analyses were used to measure mRNA and protein expression, respectively. We demonstrated that BSO significantly upregulated sEH at mRNA levels in a concentration- and time-dependent manner, leading to a significant increase in the cellular hypertrophic markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). Furthermore, BSO significantly increased the cytosolic phosphorylated IκB-α and translocation of NF-κB p50 subunits, as measured by Western blot analysis. This level of translocation was paralleled by an increase in the DNA-binding activity of NF-κB P50 subunits. Moreover, our results demonstrated that pretreatment with the NF-κB inhibitor PDTC significantly inhibited BSO-mediated induction of sEH and cellular hypertrophic marker gene expression in a dose-dependent manner. Additionally, mitogen-activated protein kinases (MAPKs) were transiently phosphorylated by BSO treatment. To understand further the role of MAPKs pathway in BSO-mediated induction of sEH mRNA, we examined the role of extracellular signal-regulated kinase (ERK), c-JunN-terminal kinase (JNK), and p38 MAPK. Indeed, treatment with the MEK/ERK signal transduction inhibitor, PD98059, partially blocked the activation of IκB-α and translocation of NF-κB p50 subunits induced by BSO. Moreover, pretreatment with MEK/ERK signal transduction inhibitors, PD98059 and U0126, significantly inhibited BSO-mediated induction of sEH and cellular hypertrophic marker gene expression. These results clearly demonstrated that the NF-κB signaling pathway is involved in BSO-mediated induction of sEH gene expression, and appears to be associated with the activation of the MAPK pathway. Furthermore, our findings provide a strong link between sEH-induced cardiac dysfunction and involvement of NF-κB in the development of cellular hypertrophy.
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Affiliation(s)
- Ghada Abdelhamid
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2N8
| | - Ayman O S El-Kadi
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2N8.
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Li W, Maloney RE, Aw TY. High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature. Redox Biol 2015; 5:80-90. [PMID: 25867911 PMCID: PMC4398791 DOI: 10.1016/j.redox.2015.03.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/27/2015] [Accepted: 03/30/2015] [Indexed: 12/24/2022] Open
Abstract
We previously demonstrated that in normal glucose (5 mM), methylglyoxal (MG, a model of carbonyl stress) induced brain microvascular endothelial cell (IHEC) dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC). Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER) was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia); moreover, barrier function remained disrupted 6 h after cell transfer to normal glucose media (acute glycemic fluctuation). Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH) synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal) levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG–occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG–occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes. Methylglyoxal (MG) induced electrical resistance (TEER)loss in brain microvascular endothelial cells. TEER loss was potentiated by hyperglycemia, and low glutathione. TEER loss was correlated with occludin-glycation and was attenuated and exacerbated by NAC and BSO, respectively. Hyperglycemia decreased glyoxalase II activity and promoted free MG accumulation. Diabetic brain in vivo exhibiteda prevalence of MG-positive microvessels and increased occludin–MG adducts.
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Affiliation(s)
- Wei Li
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Ronald E Maloney
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA
| | - Tak Yee Aw
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA; Center for Cardiovascular Disease and Sciences, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
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Yuan H, Zhang Y, Huang S, Yang Y, Gu C. Effects of exogenous glutathione and cysteine on growth, lead accumulation, and tolerance of Iris lactea var. chinensis. Environ Sci Pollut Res Int 2015; 22:2808-16. [PMID: 25212813 DOI: 10.1007/s11356-014-3535-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 08/28/2014] [Indexed: 05/20/2023]
Abstract
Effects of exogenous reduced glutathione (GSH) and cysteine (Cys) on growth, lead (Pb) accumulation, and nonprotein thiol (NPT) contents of Iris lactea var. chinensis under 100 and 500 mg L(-1) Pb stress were studied. Our results showed that 500 mg L(-1) Pb stress caused a dramatical decline in fresh weights, while the reduction of aboveground biomass was alleviated by exogenous GSH and Cys even though keeping higher Pb contents in roots and shoots. Exogenous GSH and Cys could enhance Pb accumulation in the shoots and roots compared with single Pb treatment. The promoting effect of GSH to Pb accumulation was larger than the effect of Cys, and the Pb contents in the shoots and roots treated with 500 mg L(-1) Pb + GSH reached 1,712 and 14,603 mg kg(-1), about 4.19 and 2.78 times of single 500 mg L(-1) Pb treatment, respectively. Microscopic imaging of Pb in roots and leaves showed that higher intensive fluorescence was observed in cell wall of root epidermis, stele, vascular tissues of the roots, and sclerenchyma cells of leaves treated with 500 mg L(-1) Pb + GSH and treated with 500 mg L(-1) Pb + Cys. Exogenous GSH had an apparent promoting effect on root and shoot GSH synthesis, while exogenous Cys reduced the synthesis of cellular GSH in shoot and increased Cys contents. Pb only induced the synthesis of phytochelatin (PC)2 in roots, and the PC2 content declined in GSH- and Cys-treated plant roots. These results suggested that GSH synthesis was a more effective approach to improve Pb accumulation and translocation of I. lactea var. chinensis. Further analysis of protein expression in plants by exogenous GSH and buthionine sulfoximine (BSO) application showed that the proteins regulated by GSH and BSO may constitute various enzymes involved in GSH biosynthesis and play certain roles in Pb accumulation and tolerance of I. lactea var. chinensis.
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Affiliation(s)
- Haiyan Yuan
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
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Wang Z, Mao JL, Zhao YJ, Li CY, Xiang CB. L-Cysteine inhibits root elongation through auxin/PLETHORA and SCR/SHR pathway in Arabidopsis thaliana. J Integr Plant Biol 2015; 57:186-97. [PMID: 24798139 DOI: 10.1111/jipb.12213] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 05/04/2014] [Indexed: 05/03/2023]
Abstract
L-Cysteine plays a prominent role in sulfur metabolism of plants. However, its role in root development is largely unknown. Here, we report that L-cysteine reduces primary root growth in a dosage-dependent manner. Elevating cellular L-cysteine level by exposing Arabidopsis thaliana seedlings to high L-cysteine, buthionine sulphoximine, or O-acetylserine leads to altered auxin maximum in root tips, the expression of quiescent center cell marker as well as the decrease of the auxin carriers PIN1, PIN2, PIN3, and PIN7 of primary roots. We also show that high L-cysteine significantly reduces the protein level of two sets of stem cell specific transcription factors PLETHORA1/2 and SCR/SHR. However, L-cysteine does not downregulate the transcript level of PINs, PLTs, or SCR/SHR, suggesting that an uncharacterized post-transcriptional mechanism may regulate the accumulation of PIN, PLT, and SCR/SHR proteins and auxin transport in the root tips. These results suggest that endogenous L-cysteine level acts to maintain root stem cell niche by regulating basal- and auxin-induced expression of PLT1/2 and SCR/SHR. L-Cysteine may serve as a link between sulfate assimilation and auxin in regulating root growth.
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Affiliation(s)
- Zhen Wang
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230027, China
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Clark O, Park I, Di Florio A, Cichon AC, Rustin S, Jugov R, Maeshima R, Stoker AW. Oxovanadium-based inhibitors can drive redox-sensitive cytotoxicity in neuroblastoma cells and synergise strongly with buthionine sulfoximine. Cancer Lett 2014; 357:316-327. [PMID: 25444896 DOI: 10.1016/j.canlet.2014.11.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 11/17/2014] [Accepted: 11/18/2014] [Indexed: 12/30/2022]
Abstract
In a wide range of neuroblastoma-derived lines oxovanadium compounds such as bis(maltolato)oxovanadium(IV) (BMOV) are cytotoxic. This is not explained by oxidative stress or inhibition of ion channels. Genotoxicity is unlikely given that a p53 response is absent and p53-mutant lines are also sensitive. Cytotoxicity is inhibited by N-acetyl cysteine and glutathione ester, indicating that BMOV action is sensitive to cytoplasmic redox and thiol status. Significantly, combining BMOV with glutathione synthesis inhibition greatly enhances BMOV-induced cell death. This combination treatment triggers high AKT pathway activation, highlighting the potential functional importance of PTP inhibition by BMOV. AKT activation itself, however, is not required for cytotoxicity. Oxovanadium compounds may thus represent novel leads as p53-independent therapeutics for neuroblastoma.
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Affiliation(s)
- Owen Clark
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Inhye Park
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Alessia Di Florio
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Ann-Christin Cichon
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Sarah Rustin
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Roman Jugov
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Ruhina Maeshima
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Andrew W Stoker
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
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Madadkar Haghjou M, Colville L, Smirnoff N. The induction of menadione stress tolerance in the marine microalga, Dunaliella viridis, through cold pretreatment and modulation of the ascorbate and glutathione pools. Plant Physiol Biochem 2014; 84:96-104. [PMID: 25240268 DOI: 10.1016/j.plaphy.2014.08.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/27/2014] [Indexed: 06/03/2023]
Abstract
The effect of cold pretreatment on menadione tolerance was investigated in the cells of the marine microalga, Dunaliella viridis. In addition, the involvement of ascorbate and glutathione in the response to menadione stress was tested by treating cell suspensions with l-galactono-1,4-lactone, an ascorbate precursor, and buthionine sulfoximine, an inhibitor of glutathione synthesis. Menadione was highly toxic to non cold-pretreated cells, and caused a large decrease in cell number. Cold pretreatment alleviated menadione toxicity and cold pretreated cells accumulated lower levels of reactive oxygen species, and had enhanced antioxidant capacity due to increased levels of β-carotene, reduced ascorbate and total glutathione compared to non cold-pretreated cells. Cold pretreatment also altered the response to l-galactono-1,4-lactone and buthionine sulfoximine treatments. Combined l-galactono-1,4-lactone and menadione treatment was lethal in non-cold pretreated cells, but in cold-pretreated cells it had a positive effect on cell numbers compared to menadione alone. Overall, exposure of Dunaliella cells to cold stress enhanced tolerance to subsequent oxidative stress induced by menadione.
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Affiliation(s)
| | - Louise Colville
- Seed Conservation Department, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK
| | - Nicholas Smirnoff
- University of Exeter, School of Biosciences, Geoffrey Pope Building, Exeter EX4 4QD, UK
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Övey İS, Naziroğlu M. Homocysteine and cytosolic GSH depletion induce apoptosis and oxidative toxicity through cytosolic calcium overload in the hippocampus of aged mice: involvement of TRPM2 and TRPV1 channels. Neuroscience 2014; 284:225-233. [PMID: 25305668 DOI: 10.1016/j.neuroscience.2014.09.078] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 11/15/2022]
Abstract
Oxidative stress and apoptosis were induced in neuronal cultures by inhibition of glutathione (GSH) biosynthesis with d,l-buthionine-S,R-sulfoximine (BSO). Transient receptor potential melastatin 2 (TRPM2) and transient receptor potential vanilloid 1 (TRPV1) cation channels are gated by oxidative stress. The oxidant effects of homocysteine (Hcy) may induce activation of TRPV1 and TRPM2 channels in aged mice as a model of Alzheimer's disease (AD). We tested the effects of Hcy, BSO and GSH on oxidative stress, apoptosis and Ca2+ and influx via TRPM2 and TRPV1 channels in the hippocampus of mice. Native mice hippocampal neurons were divided into five groups as follows; control, Hcy, BSO, Hcy+BSO and Hcy+BSO+GSH groups. The neurons in TRPM2 and TRPV1 experiments were stimulated by hydrogen peroxide and capsaicin, respectively. BSO and Hcy incubations increased intracellular free Ca2+ concentrations, reactive oxygen species, apoptosis, mitochondrial depolarization, and levels of caspase 3 and 9. All of these increases were reduced by GSH treatments. Treatment with 2-aminoethoxydiphenyl borate (2-APB) and N-(p-amylcinnamoyl)anthranilic acid (ACA) as potent inhibitors of TRPM2, capsazepine as a potent inhibitor of TRPV1, verapamil+diltiazem (V+D) as inhibitors of the voltage-gated Ca2+ channels (VGCC) and MK-801 as a N-methyl-d-aspartate (NMDA) channel antagonist indicated that GSH depletion and Hcy elevation activated Ca2+ entry into the neurons through TRPM2, TRPV1, VGCC and NMDA channels. Inhibitor roles of 2-APB and capsazepine on the Ca2+ entry higher than in V+D and MK-801 antagonists. In conclusion, these findings support the idea that GSH depletion and Hcy elevation can have damaging effects on hippocampal neurons by perturbing calcium homeostasis, mainly through TRPM2 and TRPV1 channels. GSH treatment can partially reverse these effects.
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Affiliation(s)
- İ S Övey
- Department of Biophysics, Faculty of Medicine, University of Suleyman Demirel, Isparta, Turkey
| | - M Naziroğlu
- Department of Biophysics, Faculty of Medicine, University of Suleyman Demirel, Isparta, Turkey; Neuroscience Research Center, University of Suleyman Demirel, Isparta, Turkey.
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64
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Floen MJ, Forred BJ, Bloom EJ, Vitiello PF. Thioredoxin-1 redox signaling regulates cell survival in response to hyperoxia. Free Radic Biol Med 2014; 75:167-77. [PMID: 25106706 PMCID: PMC4174305 DOI: 10.1016/j.freeradbiomed.2014.07.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/28/2014] [Accepted: 07/18/2014] [Indexed: 02/07/2023]
Abstract
The most common form of newborn chronic lung disease, bronchopulmonary dysplasia (BPD), is thought to be caused by oxidative disruption of lung morphogenesis, which results in decreased pulmonary vasculature and alveolar simplification. Although cellular redox status is known to regulate cellular proliferation and differentiation, redox-sensitive pathways associated with these processes in developing pulmonary epithelium are unknown. Redox-sensitive pathways are commonly regulated by cysteine thiol modifications. Therefore two thiol oxidoreductase systems, thioredoxin and glutathione, were chosen to elucidate the roles of these pathways on cell death. Studies herein indicate that thiol oxidation contributes to cell death through impaired activity of glutathione-dependent and thioredoxin (Trx) systems and altered signaling through redox-sensitive pathways. Free thiol content decreased by 71% with hyperoxic (95% oxygen) exposure. Increased cell death was observed during oxygen exposure when either the Trx or the glutathione-dependent system was pharmacologically inhibited with aurothioglucose (ATG) or buthionine sulfoximine, respectively. However, inhibition of the Trx system yielded the smallest decrease in free thiol content (1.44% with ATG treatment vs 21.33% with BSO treatment). Although Trx1 protein levels were unchanged, Trx1 function was impaired during hyperoxic treatment as indicated by progressive cysteine oxidation. Overexpression of Trx1 in H1299 cells utilizing an inducible construct increased cell survival during hyperoxia, whereas siRNA knockdown of Trx1 during oxygen treatment reduced cell viability. Overall, this indicated that a comparatively small pool of proteins relies on Trx redox functions to mediate cell survival in hyperoxia, and the protective functions of Trx1 are progressively lost by its oxidative inhibition. To further elucidate the role of Trx1, potential Trx1 redox protein-protein interactions mediating cytoprotection and cell survival pathways were determined by utilizing a substrate trap (mass action trapping) proteomics approach. With this method, known Trx1 targets were detected, including peroxiredoxin-1as well as novel targets, including two HSP90 isoforms (HSP90AA1 and HSP90AB1). Reactive cysteines within the structure of HSP90 are known to modulate its ATPase-dependent chaperone activity through disulfide formation and S-nitrosylation. Whereas HSP90 expression is unchanged at the protein level during hyperoxic exposure, siRNA knockdown significantly increased hyperoxic cell death by 2.5-fold, indicating cellular dependence on HSP90 chaperone functions in response to hyperoxic exposure. These data support the hypothesis that hyperoxic impairment of Trx1 has a negative impact on HSP90-oxidative responses critical to cell survival, with potential implications for pathways implicated in lung development and the pathogenesis of BPD.
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Affiliation(s)
- Miranda J Floen
- Basic Biomedical Sciences and The University of South Dakota Sanford School of Medicine, Sioux Falls, SD 57105, USA
| | - Benjamin J Forred
- Children׳s Health Research Center, Sanford Research, Sioux Falls, SD 57104, USA
| | - Elliot J Bloom
- Children׳s Health Research Center, Sanford Research, Sioux Falls, SD 57104, USA
| | - Peter F Vitiello
- Department of Pediatrics, The University of South Dakota Sanford School of Medicine, Sioux Falls, SD 57105, USA; Children׳s Health Research Center, Sanford Research, Sioux Falls, SD 57104, USA.
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Nadeem A, Siddiqui N, Alharbi NO, Alharbi MM, Imam F, Sayed-Ahmed MM. Glutathione modulation during sensitization as well as challenge phase regulates airway reactivity and inflammation in mouse model of allergic asthma. Biochimie 2014; 103:61-70. [PMID: 24742380 DOI: 10.1016/j.biochi.2014.04.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 04/01/2014] [Indexed: 12/15/2022]
Abstract
Glutathione, being a major intracellular redox regulator has been shown to be implicated in regulation of airway reactivity and inflammation. However, no study so far has investigated the effect of glutathione depletion/repletion during sensitization and challenge phases separately, which could provide an important insight into the pathophysiology of allergic asthma. The aim of the present study was to evaluate the role of glutathione depletion/repletion during sensitization and challenge phases separately in a mouse model of allergic asthma. Buthionine sulphoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase or N-acetyl cysteine (NAC), a thiol donor were used for depletion or repletion of glutathione levels respectively during both sensitization and challenge phases separately followed by assessment of airway reactivity, inflammation and oxidant-antioxidant balance in allergic mice. Depletion of glutathione with BSO during sensitization as well as challenge phase worsened allergen induced airway reactivity/inflammation and caused greater oxidant-antioxidant imbalance as reflected by increased NADPH oxidase expression/reactive oxygen species (ROS) generation/lipid peroxides formation and decreased total antioxidant capacity. On the other hand, repletion of glutathione pool by NAC during sensitization and challenge phases counteracted allergen induced airway reactivity/inflammation and restored oxidant-antioxidant balance through a decrease in NADPH oxidase expression/ROS generation/lipid peroxides formation and increase in total antioxidant capacity. Taken together, these findings suggest that depletion or repletion of glutathione exacerbates or ameliorates allergic asthma respectively by regulation of airway oxidant-antioxidant balance. This might have implications towards increased predisposition to allergy by glutathione depleting environmental pollutants.
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Affiliation(s)
- Ahmed Nadeem
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
| | - Nahid Siddiqui
- Amity Institute of Biotechnology, Amity University, Noida, India
| | - Naif O Alharbi
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohammad M Alharbi
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Faisal Imam
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohamed M Sayed-Ahmed
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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66
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Barhoumi R, Mouneimne Y, Chapkin RS, Burghardt RC. Effects of fatty acids on benzo[a]pyrene uptake and metabolism in human lung adenocarcinoma A549 cells. PLoS One 2014; 9:e90908. [PMID: 24651647 PMCID: PMC3961214 DOI: 10.1371/journal.pone.0090908] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/06/2014] [Indexed: 11/18/2022] Open
Abstract
Dietary supplementation with natural chemoprotective agents is receiving considerable attention because of health benefits and lack of toxicity. In recent in vivo and in vitro experimental studies, diets rich in n-3 polyunsaturated fatty acids have been shown to provide significant anti-tumor action. In this investigation, the effects of control fatty acids (oleic acid (OA), linoleic acid (LA)) and n-3 PUFA, e.g., docosahexaenoic acid (DHA) on the uptake and metabolism of the carcinogenic polycyclic aromatic hydrocarbon, benzo[a]pyrene (BaP) was investigated in A549 cells, a human adenocarcinoma alveolar basal epithelial cell line. A549 cells activate BaP through the cytochrome P450 enzyme system to form reactive metabolites, a few of which covalently bind to DNA and proteins. Therefore, multiphoton microscopy spectral analysis combined with linear unmixing was used to identify the parent compound and BaP metabolites formed in cells, in the presence and absence of fatty acids. The relative abundance of select metabolites was associated with altered P450 activity as determined using ethoxyresorufin-O-deethylase activity in cells cultured in the presence of BSA-conjugated fatty acids. In addition, the parent compound within cellular membranes increases significantly in the presence of each of the fatty acids, with the greatest accumulation observed following DHA treatment. DHA treated cells exhibit significantly lower pyrene-like metabolites indicative of lower adducts including DNA adducts compared to control BSA, OA or LA treated cells. Further, DHA reduced the abundance of the proximate carcinogen BaP 7,8-dihydrodiol and the 3-hydroxybenzo[a]pyrene metabolites compared to other treatments. The significant changes in BaP metabolites in DHA treated cells may be mediated by the effects on the physicochemical properties of the membrane known to affect enzyme activity related to phase I and phase II metabolism. In summary, DHA is a highly bioactive chemo-protective agent capable of modulating BaP-induced DNA adducts.
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Affiliation(s)
- Rola Barhoumi
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
| | | | - Robert S. Chapkin
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
- Department of Nutrition and Food Science, Texas A&M University, College Station, Texas, United States of America
| | - Robert C. Burghardt
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
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67
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Bayram B, Rimbach G, Frank J, Esatbeyoglu T. Rapid method for glutathione quantitation using high-performance liquid chromatography with coulometric electrochemical detection. J Agric Food Chem 2014; 62:402-408. [PMID: 24328299 DOI: 10.1021/jf403857h] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A rapid, sensitive, and direct method (without derivatization) was developed for the detection of reduced glutathione (GSH) in cultured hepatocytes (HepG2 cells) using high-performance liquid chromatography with electrochemical detection (HPLC-ECD). The method was validated according to the guidelines of the U.S. Food and Drug Administration in terms of linearity, lower limit of quantitation (LOQ), lower limit of detection (LOD), precision, accuracy, recovery, and stabilities of GSH standards and quality control samples. The total analysis time was 5 min, and the retention time of GSH was 1.78 min. Separation was carried out isocratically using 50 mM sodium phosphate (pH 3.0) as a mobile phase with a fused-core column. The detector response was linear between 0.01 and 80 μmol/L, and the regression coefficient (R(2)) was >0.99. The LOD for GSH was 15 fmol, and the intra- and interday recoveries ranged between 100.7 and 104.6%. This method also enabled the rapid detection (in 4 min) of other compounds involved in GSH metabolism such as uric acid, ascorbic acid, and glutathione disulfite. The optimized and validated HPLC-ECD method was successfully applied for the determination of GSH levels in HepG2 cells treated with buthionine sulfoximine (BSO), an inhibitor, and α-lipoic acid (α-LA), an inducer of GSH synthesis. As expected, the amount of GSH concentration-dependently decreased with BSO and increased with α-LA treatments in HepG2 cells. This method could also be useful for the quantitation of GSH, uric acid, ascorbic acid, and glutathione disulfide in other biological matrices such as tissue homogenates and blood.
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Affiliation(s)
- Banu Bayram
- Institute of Human Nutrition and Food Science, Christian-Albrechts-University , Hermann Rodewald Strasse 6, 24098 Kiel, Germany
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68
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Nigmatullina LR, Rumiantseva NI, Kostiukova IA. [Effect of D,L-buthionine-S,R-sulfoximine on the ratio of glutathione forms and the growth of tatar buckwheat calli]. Ontogenez 2014; 45:50-62. [PMID: 25720265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We studied the intracellular content of reduced (GSH) and oxidized (GSSG) glutathione, glutathione reductase activity, glutathione-S-transferase, and ascorbate peroxidase in morphogenic and nonmorphogenic Tatar buckwheat calli during the culture cycle as well as under the treatment with D,L-buthionine-S,R-sulfoximine (BSO), an inhibitor of γ-glutamylcysteine synthase, the first enzyme of glutathione biosynthesis. We found that, during passaging, cultures only slightly differed in total glutathione content; however, the content of GSH was higher in the morphogenic culture, whereas the content of GSSG was higher in the nonmorphogenic culture. In the morphogenic callus, the glutathione-S-transferase activity was 10-20 times higher and the glutathione reductase activity, was 2-2.5 times lower than in the nonmorphogenic callus. Under the treatment with BSO, the decrease in the GSH content in the morphogenic callus was temporary (on day 6-8 of passage), whereas that in the nonmorphogenic callus decreased within a day and remained lower than in the control throughout the entire passage. In the morphogenic callus, BSO did not affect the content of GSSG, whereas it caused GSSG accumulation in the nonmorphogenic callus. These differences are probably due to the fact that, in the BSO-containing medium, glutathione reductase is activated in the morphogenic callus and, conversely, inhibited in the nonmorphogenic callus. Although BSO caused a decrease in the total glutathione content only in the nonmorphogenic culture, the cytostatic effect of BSO was more pronounced in the morphogenic callus. In addition, BSO also had a negative effect on the differentiation ofproembryonic cell complexes in the morphogenic callus. The role of the glutathione redox status in maintaining the embryogenic activity of cultured plant cells is discussed.
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69
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Cho SH, Guengerich FP. In vivo roles of conjugation with glutathione and O6-alkylguanine DNA-alkyltransferase in the mutagenicity of the bis-electrophiles 1,2-dibromoethane and 1,2,3,4-diepoxybutane in mice. Chem Res Toxicol 2013; 26:1765-74. [PMID: 24191644 PMCID: PMC3889014 DOI: 10.1021/tx4003534] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Several studies with bacteria and in vitro mammalian systems have provided evidence of the roles of two thiol-based conjugation systems, glutathione (GSH) transferase and O(6)-alkylguanine DNA-alkyltransferase (AGT), in the bioactivation of the bis-electrophiles 1,2-dibromoethane and 1,2,3,4-diepoxybutane (DEB), the latter an oxidation product of 1,3-butadiene. The in vivo relevance of these conjugation reactions to biological activity in mammals has not been addressed, particularly with DEB. In this work, we used transgenic Big Blue mice, utilizing the cII gene, to examine the effects of manipulation of conjugation pathways on liver mutations arising from dibromoethane and DEB in vivo. Treatment of the mice with butathionine sulfoxime (BSO) prior to dibromoethane lowered hepatic GSH levels, dibromoethane-GSH DNA adduct levels (N(7)-guanyl), and the cII mutation frequency. Administration of O(6)-benzylguanine (O(6)-BzGua), an inhibitor of AGT, did not change the mutation frequency. Depletion of GSH (BSO) and AGT (O(6)-BzGua) lowered the mutation frequency induced by DEB, and BSO lowered the levels of GSH-DEB N(7)-guanyl and N(6)-adenyl DNA adducts. Our results provide evidence that the GSH conjugation pathway is a major in vivo factor in dibromoethane genotoxicity; both GSH conjugation and AGT conjugation are major factors in the genotoxicity of DEB. The latter findings are considered to be relevant to the carcinogenicity of 1,3-butadiene.
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Affiliation(s)
| | - F. Peter Guengerich
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
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Chen HJ, Huang CS, Huang GJ, Chow TJ, Lin YH. NADPH oxidase inhibitor diphenyleneiodonium and reduced glutathione mitigate ethephon-mediated leaf senescence, H2O2 elevation and senescence-associated gene expression in sweet potato (Ipomoea batatas). J Plant Physiol 2013; 170:1471-83. [PMID: 23834930 DOI: 10.1016/j.jplph.2013.05.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 05/30/2013] [Accepted: 05/30/2013] [Indexed: 05/23/2023]
Abstract
Ethephon, an ethylene releasing compound, promoted leaf senescence, H2O2 elevation, and senescence-associated gene expression in sweet potato. It also affected the glutathione and ascorbate levels, which in turn perturbed H2O2 homeostasis. The decrease of reduced glutathione and the accumulation of dehydroascorbate correlated with leaf senescence and H2O2 elevation at 72h in ethephon-treated leaves. Exogenous application of reduced glutathione caused quicker and significant increase of its intracellular level and resulted in the attenuation of leaf senescence and H2O2 elevation. A small H2O2 peak produced within the first 4h after ethephon application was also eliminated by reduced glutathione. Diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, delayed leaf senescence and H2O2 elevation at 72h, and its influence was effective only within the first 4h after ethephon treatment. Ethephon-induced senescence-associated gene expression was repressed by DPI and reduced glutathione at 72h in pretreated leaves. Leaves treated with l-buthionine sulfoximine, an endogenous glutathione synthetase inhibitor, did enhance senescence-associated gene expression, and the activation was strongly repressed by reduced glutathione. In conclusion, ethephon-mediated leaf senescence, H2O2 elevation and senescence-associated gene expression are all alleviated by reduced glutathione and NADPH oxidase inhibitor DPI. The speed and the amount of intracellular reduced glutathione accumulation influence its effectiveness of protection against ethephon-mediated effects. Reactive oxygen species generated from NADPH oxidase likely serves as an oxidative stress signal and participates in ethephon signaling. The possible roles of NADPH oxidase and reduced glutathione in the regulation of oxidative stress signal in ethephon are discussed.
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Affiliation(s)
- Hsien-Jung Chen
- Department of Biological Sciences, National Sun Yat-sen University, 804 Kaohsiung, Taiwan.
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Wu D, Cederbaum AI. Inhibition of autophagy promotes CYP2E1-dependent toxicity in HepG2 cells via elevated oxidative stress, mitochondria dysfunction and activation of p38 and JNK MAPK. Redox Biol 2013; 1:552-65. [PMID: 24273738 PMCID: PMC3836279 DOI: 10.1016/j.redox.2013.10.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 10/27/2013] [Indexed: 02/07/2023] Open
Abstract
Autophagy has been shown to be protective against drug and alcohol-induced liver injury. CYP2E1 plays a role in the toxicity of ethanol, carcinogens and certain drugs. Inhibition of autophagy increased ethanol-toxicity and accumulation of fat in wild type and CYP2E1 knockin mice but not in CYP2E1 knockout mice as well as in HepG2 cells expressing CYP2E1 (E47 cells) but not HepG2 cells lacking CYP2E1 (C34 cells). The goal of the current study was to evaluate whether modulation of autophagy can affect CYP2E1-dependent cytotoxicity in the E47 cells. The agents used to promote CYP2E1 -dependent toxicity were a polyunsaturated fatty acid, arachidonic acid (AA), buthionine sulfoximine (BSO), which depletes GSH, and CCl4, which is metabolized to the CCl3 radical. These three agents produced a decrease in E47 cell viability which was enhanced upon inhibition of autophagy by 3-methyladenine (3-MA) or Atg 7 siRNA. Toxicity was lowered by rapamycin which increased autophagy and was much lower to the C34 cells which do not express CYP2E1. Toxicity was mainly necrotic and was associated with an increase in reactive oxygen production and oxidative stress; 3-MA increased while rapamycin blunted the oxidative stress. The enhanced toxicity and ROS formation produced when autophagy was inhibited was prevented by the antioxidant N-Acetyl cysteine. AA, BSO and CCl4 produced mitochondrial dysfunction, lowered cellular ATP levels and elevated mitochondrial production of ROS. This mitochondrial dysfunction was enhanced by inhibition of autophagy with 3-MA but decreased when autophagy was increased by rapamycin. The mitogen activated protein kinases p38 MAPK and JNK were activated by AA especially when autophagy was inhibited and chemical inhibitors of p38 MAPK and JNK lowered the elevated toxicity of AA produced by 3-MA. These results show that autophagy was protective against the toxicity produced by several agents known to be activated by CYP2E1. Since CYP2E1 plays an important role in the toxicity of ethanol, drugs and carcinogens and is activated under various pathophysiological conditions such as diabetes, NASH and obesity, attempts to stimulate autophagy may be beneficial in preventing/lowering CYP2E1/ethanol liver injury.
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Key Words
- 3-MA, 3-methyadenine
- AA, arachidonic acid
- Autophagy
- BSO, L-buthionine sulfoximine
- C34 cells, HepG2 cells which do not express CYP2E1
- CCl4, carbon tetrachloride
- CYP2E1
- CYP2E1, cytochrome P4502E1, E47 cells, HepG2 cells which express CYP2E1
- Cox IV, cytochrome oxidase subunit 4
- Cytotoxicity
- DCFDA, 2′-7′-dichlorofluorescin-diacetate
- GSH, reduced glutathione
- JNK
- MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide
- Mitochondria dysfunction
- NAC, N-acetyl-cysteine
- P38 MAPK
- ROS
- ROS, reactive oxygen species
- Rap, rapamycin
- SOD, superoxide dismutase
- TBARs, thiobarbituric acid-reactive substances
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Affiliation(s)
| | - Arthur I. Cederbaum
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, Box 1603, One Gustave L. Levy Place, New York, NY 10029, USA
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Kıroğlu OE, Aydinoglu F, Oğülener N. The effects of thiol modulators on nitrergic nerve- and S-nitrosothiols-induced relaxation in duodenum. J Basic Clin Physiol Pharmacol 2013; 24:143-50. [PMID: 23412870 DOI: 10.1515/jbcpp-2012-0054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 01/21/2013] [Indexed: 11/15/2022]
Abstract
BACKGROUND The aim of this study was to investigate whether thiols are involved in the nitrergic neurotransmission in mouse duodenum. METHODS The effects of thiol-modulating agents, ethacrynic acid (100 μM), a non-specific sulfhydryl alkylator, and diamide (100 μM), an alkylating agent that oxidizes protein sulfhydryl groups and depletes intracellular glutathione, on relaxations to nitrergic stimulation (electrical field stimulation, EFS;10 Hz, 25 V, 1 ms, 15 s-train), S-nitrosoglutathione (GSNO; 5 μM), S-nitroso-acetylpenicillamine (SNAP; 5 μM), and S-nitrosocysteine (CysNO; 10 μM) were investigated. Moreover, the effects of buthionine sulfoximine (100 μM), an inhibitor of γ-glutamylcysteine synthetase, and sulfobromophthalein (100 μM), an inhibitor of glutathione-S-transferase, were studied on relaxant responses to EFS and S-nitrosothiols in mouse duodenum. RESULTS Exogenous free thiol, glutathione (GSH, 100 μM) did not influence relaxation to EFS, GSNO, SNAP, and CysNO. Ethacrynic acid and diamide significantly decreased relaxation of duodenum to EFS, GSNO, SNAP, and CysNO. This inhibition was prevented by addition of GSH. Buthionine sulfoximine and sulfobromophthalein significantly decreased relaxation to EFS and GSNO but did not influence relaxation to SNAP and CysNO. The inhibitory effect of buthionine sulfoximine and sulfobromophthalein on the relaxant response to EFS and GSNO was prevented by addition of GSH. CONCLUSIONS These results suggest that relaxation to nitrergic stimulation is thiol-dependent, and nitrosothiols, possibly S-nitrosoglutathione may play a role, as an intermediate compound in nitrergic neurotransmission in mouse duodenum.
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Adams DJ, Boskovic ZV, Theriault JR, Wang AJ, Stern A, Wagner BK, Shamji A, Schreiber SL. Discovery of small-molecule enhancers of reactive oxygen species that are nontoxic or cause genotype-selective cell death. ACS Chem Biol 2013; 8:923-9. [PMID: 23477340 PMCID: PMC3658551 DOI: 10.1021/cb300653v] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/11/2013] [Indexed: 02/08/2023]
Abstract
Elevation of reactive oxygen species (ROS) levels has been observed in many cancer cells relative to nontransformed cells, and recent reports have suggested that small-molecule enhancers of ROS may selectively kill cancer cells in various in vitro and in vivo models. We used a high-throughput screening approach to identify several hundred small-molecule enhancers of ROS in a human osteosarcoma cell line. A minority of these compounds diminished the viability of cancer cell lines, indicating that ROS elevation by small molecules is insufficient to induce death of cancer cell lines. Three chemical probes (BRD5459, BRD56491, BRD9092) are highlighted that most strongly elevate markers of oxidative stress without causing cell death and may be of use in a variety of cellular settings. For example, combining nontoxic ROS-enhancing probes with nontoxic doses of L-buthionine sulfoximine, an inhibitor of glutathione synthesis previously studied in cancer patients, led to potent cell death in more than 20 cases, suggesting that even nontoxic ROS-enhancing treatments may warrant exploration in combination strategies. Additionally, a few ROS-enhancing compounds that contain sites of electrophilicity, including piperlongumine, show selective toxicity for transformed cells over nontransformed cells in an engineered cell-line model of tumorigenesis. These studies suggest that cancer cell lines are more resilient to chemically induced increases in ROS levels than previously thought and highlight electrophilicity as a property that may be more closely associated with cancer-selective cell death than ROS elevation.
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Affiliation(s)
- Drew J. Adams
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Zarko V. Boskovic
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
- Department of Chemistry and Chemical
Biology, Harvard University, Cambridge,
Massachusetts 02138, United States
| | - Jimmy R. Theriault
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Alex J. Wang
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Andrew
M. Stern
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Bridget K. Wagner
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Alykhan
F. Shamji
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Stuart L. Schreiber
- Chemical
Biology Program, Chemical Biology Platform, and Howard Hughes Medical Institute, Broad Institute, 7 Cambridge Center,
Cambridge, Massachusetts 02142, United States
- Department of Chemistry and Chemical
Biology, Harvard University, Cambridge,
Massachusetts 02138, United States
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Lee J, Koh K, Kim YE, Ahn JH, Kim S. Upregulation of Nrf2 expression by human cytomegalovirus infection protects host cells from oxidative stress. J Gen Virol 2013; 94:1658-1668. [PMID: 23580430 DOI: 10.1099/vir.0.052142-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
NF-E2 related factor 2 (Nrf2) is a transcription factor that plays a key role(s) in cellular defence against oxidative stress. In this study, we showed that the expression of Nrf2 was upregulated in primary human foreskin fibroblasts (HFFs), following human cytomegalovirus (HCMV/HHV-5) infection. The expression of haem oxygenase-1, a downstream target of Nrf2, was also increased by HCMV infection, and this induction was suppressed in HFFs expressing a small hairpin RNA (shRNA) against Nrf2. The HCMV-mediated increase in Nrf2 expression was abolished when UV-irradiated virus was used or when the activity of casein kinase 2 was inhibited. Host cells infected by HCMV had higher survival rates following oxidative stress induced by buthionine sulfoximine compared with uninfected control cells, but this cell-protective effect was abolished by the use of Nrf2 shRNA. Our results suggest that HCMV-mediated activation of Nrf2 might be beneficial to the virus by increasing the host cell's ability to cope with oxidative stress resulting from viral infection and/or inflammation.
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Affiliation(s)
- Junsub Lee
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Kyungmi Koh
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Young-Eui Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Kyonggido 440-746, Korea
| | - Jin-Hyun Ahn
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Kyonggido 440-746, Korea
| | - Sunyoung Kim
- School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
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75
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Saccà F, Marsili A, Puorro G, Antenora A, Pane C, Tessa A, Scoppettuolo P, Nesti C, Brescia Morra V, De Michele G, Santorelli FM, Filla A. Clinical use of frataxin measurement in a patient with a novel deletion in the FXN gene. J Neurol 2013; 260:1116-21. [PMID: 23196337 DOI: 10.1007/s00415-012-6770-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 11/11/2012] [Accepted: 11/16/2012] [Indexed: 10/27/2022]
Abstract
Friedreich ataxia (FRDA) is caused by a GAA expansion in the first intron of the FXN gene, which encodes frataxin. Four percent of patients harbor a point mutation on one allele and a GAA expansion on the other. We studied an Italian patient presenting with symptoms suggestive of FRDA, and carrying a single expanded 850 GAA allele. As a second diagnostic step, frataxin was measured in peripheral blood mononuclear cells, and proved to be in the pathological range (2.95 pg/μg total protein, 12.7 % of control levels). Subsequent sequencing revealed a novel deletion in exon 5a (c.572delC) which predicted a frameshift at codon 191 and a premature truncation of the protein at codon 194 (p.T191IfsX194). FXN/mRNA expression was reduced to 69.2 % of control levels. Clinical phenotype was atypical with absent dysarthria, and rapid disease progression. L-Buthionine-sulphoximine treatment of the proband's lymphoblasts showed a severe phenotype as compared to classic FRDA.
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Affiliation(s)
- Francesco Saccà
- Department of Neurological Sciences, University Federico II, Via Pansini 5, 80131 Naples, NA, Italy.
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Park MH, Kim SY, Moon C, Bae YC, Moon JI, Moon C. Differential cell death and Bcl-2 expression in the mouse retina after glutathione decrease by systemic D,L-buthionine sulphoximine administration. Mol Cells 2013; 35:235-42. [PMID: 23430084 PMCID: PMC3887915 DOI: 10.1007/s10059-013-2276-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 12/17/2012] [Accepted: 12/26/2012] [Indexed: 01/11/2023] Open
Abstract
Glutathione (GSH) plays a critical role in cellular defense against unregulated oxidative stress in mammalian cells including neurons. We previously demonstrated that GSH decrease using [D, L]-buthionine sulphoximine (BSO) induces retinal cell death, but the underlying mechanisms of this are still unclear. Here, we demonstrated that retinal GSH level is closely related to retinal cell death as well as expression of an anti-apoptotic molecule, Bcl-2, in the retina. We induced differential expression of retinal GSH by single and multiple administrations of BSO, and examined retinal GSH levels and retinal cell death in vivo. Single BSO administration showed a transient decrease in the retinal GSH level, whereas multiple BSO administration showed a persistent decrease in the retinal GSH level. Retinal cell death also showed similar patterns: transient increases of retinal cell death were observed after single BSO administration, whereas persistent increases of retinal cell death were observed after multiple BSO administration. Changes in the retinal GSH level affected Bcl-2 expression in the retina. Immunoblot and immunohistochemical analyses showed that single and multiple administration of BSO induced differential expressions of Bcl-2 in the retina. Taken together, the results of our study suggest that the retinal GSH is important for the survival of retinal cells, and retinal GSH appears to be deeply related to Bcl-2 expression in the retina. Thus, alteration of Bcl-2 expression may provide a therapeutic tool for retinal degenerative diseases caused by retinal oxidative stress such as glaucoma or retinopathy.
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Affiliation(s)
- Myoung Hee Park
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul 137–701,
Korea
| | - So Yeun Kim
- Department of Brain Science, Graduate School, Daegu Gyeongbuk Institute of Science and Technology, Daegu 711–873,
Korea
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 700-412,
Korea
| | - Chanil Moon
- Department of Cardiology, School of Medicine, Hanyang University, Seoul 133–791,
Korea
| | - Young Chul Bae
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 700-412,
Korea
| | - Jung-Il Moon
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul 137–701,
Korea
| | - Cheil Moon
- Department of Brain Science, Graduate School, Daegu Gyeongbuk Institute of Science and Technology, Daegu 711–873,
Korea
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77
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You BR, Park WH. Suberoyl bishydroxamic acid-induced apoptosis in HeLa cells via ROS-independent, GSH-dependent manner. Mol Biol Rep 2012; 40:3807-16. [PMID: 23269626 DOI: 10.1007/s11033-012-2459-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 12/18/2012] [Indexed: 01/13/2023]
Abstract
Suberoyl bishydroxamic acid (SBHA) is a HDAC inhibitor that can regulate many biological functions including apoptosis and proliferation in various cancer cells. Here, we evaluated the effect of SBHA on the growth of HeLa cervical cancer cells in relation to apoptosis, reactive oxygen species (ROS) and glutathione (GSH) levels. Dose-dependent inhibition of cell growth was observed in HeLa cells with an IC50 of approximately 15 μM at 72 h. SBHA also induced apoptosis in HeLa cells, as evidenced by sub-G1 cells, annexin V-FITC staining cells, activations of caspase 3 and 8, and the loss of mitochondrial membrane potential (ΔΨm). In addition, all of the tested caspase inhibitors rescued some cells from SBHA-induced HeLa cell death. SBHA increased ROS levels including O2(•-) and induced GSH depletion in HeLa cells. Generally, caspase inhibitors did not affect ROS levels in SBHA-treated HeLa cells, but they significantly prevented GSH depletion in these cells. Furthermore, while the well-known antioxidants, N-acetyl cysteine and vitamin C, did not affect cell death, ROS level or GSH depletion in SBHA-treated HeLa cells, L-buthionine sulfoximine, a GSH synthesis inhibitor, enhanced cell death and GSH depletion in these cells. In conclusion, SBHA inhibits the growth of HeLa cervical cancer cells via caspase-dependent apoptosis, and the inhibition is independent of ROS level changes, but dependent on GSH level changes.
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Affiliation(s)
- Bo Ra You
- Department of Physiology, Medical School, Research Institute for Endocrine Sciences, Chonbuk National University, Jeon-Ju 561-180, Republic of Korea
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78
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Kaushik G, Kaushik T, Yadav SK, Sharma SK, Ranawat P, Khanduja KL, Pathak CM. Curcumin sensitizes lung adenocarcinoma cells to apoptosis via intracellular redox status mediated pathway. Indian J Exp Biol 2012; 50:853-861. [PMID: 23986968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The present study demonstrates that curcumin acts as pro-oxidant and sensitizes human lung adenocarcinoma epithelial cells (A549) to apoptosis via intracellular redox status mediated pathway. Results indicated that curcumin induced cell toxicity (light microscopy and MTT assay) and apoptosis (AnnexinV-FITC/PI labeling and caspase-3 activity) in these cells. These events seem to be mediated through generation of reactive oxygen species (ROS) and superoxide radicals (SOR) and enhanced levels of lipid peroxidation. These changes were accompanied by increase in oxidized glutathione (GSSG), reduced glutathione (GSH) and gamma-glutamylcysteine synthetase (gamma-GCS) activity, but decrease in GSH/GSSG ratio. The induction of apoptosis and decrease in GSH/GSSG ratio was also accompanied by sustained phosphorylation and activation of p38 mitogen activated protein kinase (MAPK). On the other hand, addition of N-acetyl cysteine (NAC), an antioxidant, blocked the curcumin-induced ROS production and rescued malignant cells from curcumin-induced apoptosis through caspase-3 deactivation. However, L-buthionine sulfoximine (BSO), a GSH synthesis blocking agent, further enhanced curcumin-induced ROS production and apoptosis in A549 cells. Decreased GSH/GSSG ratio seems to be a crucial factor for the activation of MAPK signaling cascade by curcumin. The study therefore, provides an insight into the molecular mechanism involved in sensitization of lung adenocarcinoma cells to apoptosis by curcumin.
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Affiliation(s)
- Gaurav Kaushik
- Department of Biophysics, Post Graduate Institute of Medical Education and Research, Chandigarh 160 012, India
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79
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Hanot M, Boivin A, Malésys C, Beuve M, Colliaux A, Foray N, Douki T, Ardail D, Rodriguez-Lafrasse C. Glutathione depletion and carbon ion radiation potentiate clustered DNA lesions, cell death and prevent chromosomal changes in cancer cells progeny. PLoS One 2012. [PMID: 23185232 PMCID: PMC3502420 DOI: 10.1371/journal.pone.0044367] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Poor local control and tumor escape are of major concern in head-and-neck cancers treated by conventional radiotherapy or hadrontherapy. Reduced glutathione (GSH) is suspected of playing an important role in mechanisms leading to radioresistance, and its depletion should enable oxidative stress insult, thereby modifying the nature of DNA lesions and the subsequent chromosomal changes that potentially lead to tumor escape. This study aimed to highlight the impact of a GSH-depletion strategy (dimethylfumarate, and l-buthionine sulfoximine association) combined with carbon ion or X-ray irradiation on types of DNA lesions (sparse or clustered) and the subsequent transmission of chromosomal changes to the progeny in a radioresistant cell line (SQ20B) expressing a high endogenous GSH content. Results are compared with those of a radiosensitive cell line (SCC61) displaying a low endogenous GSH level. DNA damage measurements (γH2AX/comet assay) demonstrated that a transient GSH depletion in resistant SQ20B cells potentiated the effects of irradiation by initially increasing sparse DNA breaks and oxidative lesions after X-ray irradiation, while carbon ion irradiation enhanced the complexity of clustered oxidative damage. Moreover, residual DNA double-strand breaks were measured whatever the radiation qualities. The nature of the initial DNA lesions and amount of residual DNA damage were similar to those observed in sensitive SCC61 cells after both types of irradiation. Misrepaired or unrepaired lesions may lead to chromosomal changes, estimated in cell progeny by the cytome assay. Both types of irradiation induced aberrations in nondepleted resistant SQ20B and sensitive SCC61 cells. The GSH-depletion strategy prevented the transmission of aberrations (complex rearrangements and chromosome break or loss) in radioresistant SQ20B only when associated with carbon ion irradiation. A GSH-depleting strategy combined with hadrontherapy may thus have considerable advantage in the care of patients, by minimizing genomic instability and improving the local control.
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Affiliation(s)
- Maïté Hanot
- Laboratoire de Radiobiologie Cellulaire et Moléculaire, EMR3738, Faculté de Médecine Lyon-Sud, Oullins, France
- Fondation Synergie Lyon Cancer, Lyon, France
| | - Anthony Boivin
- Laboratoire de Radiobiologie Cellulaire et Moléculaire, EMR3738, Faculté de Médecine Lyon-Sud, Oullins, France
| | - Céline Malésys
- Laboratoire de Radiobiologie Cellulaire et Moléculaire, EMR3738, Faculté de Médecine Lyon-Sud, Oullins, France
| | - Michaël Beuve
- Institut de Physique Nucléaire de Lyon, UMR 5822, Université Lyon 1, IN2P3/CNRS, Villeurbanne, France
| | - Anthony Colliaux
- Institut de Physique Nucléaire de Lyon, UMR 5822, Université Lyon 1, IN2P3/CNRS, Villeurbanne, France
| | - Nicolas Foray
- Institut National de la Santé et de la Recherche Médicale, U836, Groupe de Radiobiologie, Faculté de Médecine de Lyon-Sud, Oullins, France
| | - Thierry Douki
- Commissariat à l'Energie Atomique (CEA), Service de Chimie Inorganique et Biologique UMR-E 3 (CEA-UJF), Laboratoire Lésions des Acides Nucléiques, Grenoble, France
| | - Dominique Ardail
- Laboratoire de Radiobiologie Cellulaire et Moléculaire, EMR3738, Faculté de Médecine Lyon-Sud, Oullins, France
| | - Claire Rodriguez-Lafrasse
- Laboratoire de Radiobiologie Cellulaire et Moléculaire, EMR3738, Faculté de Médecine Lyon-Sud, Oullins, France
- Unité Médicale d'Oncologie Moléculaire et Transfert, Hospices Civils Lyon, Centre de Biologie Sud, Centre Hospitalier Lyon-Sud, Pierre Bénite, France
- * E-mail:
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80
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Njomnang Soh P, Witkowski B, Gales A, Huyghe E, Berry A, Pipy B, Benoit-Vical F. Implication of glutathione in the in vitro antiplasmodial mechanism of action of ellagic acid. PLoS One 2012; 7:e45906. [PMID: 23029306 PMCID: PMC3461036 DOI: 10.1371/journal.pone.0045906] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/23/2012] [Indexed: 12/05/2022] Open
Abstract
The search for new antimalarial chemotherapy has become increasingly urgent due to parasite resistance to current drugs. Ellagic acid (EA) is a polyphenol, recently found in various plant products, that has effective antimalarial activity in vitro and in vivo without toxicity. To further understand the antimalarial mechanism of action of EA in vitro, we evaluated the effects of EA, ascorbic acid and N-acetyl-L-cysteine (NAC), alone and/or in combination on the production of reactive oxygen species (ROS) during the trophozoite and schizonte stages of the erythrocytic cycle of P. falciparum. The parasitized erythrocytes were pre-labelled with DCFDA (dichlorofluorescein diacetate). We showed that NAC had no effect on ROS production, contrary to ascorbic acid and EA, which considerably reduced ROS production. Surprisingly, EA reduced the production of the ROS with concentrations (6.6×10−9 − 6.6×10−6 M) ten-fold lower than ascorbic acid (113×10−6 M). Additionally, the in vitro drug sensitivity of EA with antioxidants showed that antiplasmodial activity is independent of the ROS production inside parasites, which was confirmed by the additive activity of EA and desferrioxamine. Finally, EA could act by reducing the glutathione content inside the Plasmodium parasite. This was consolidated by the decrease in the antiplasmodial efficacy of EA in the murine model Plasmodium yoelii- high GSH strain, known for its high glutathione content. Given its low toxicity and now known mechanism of action, EA appears as a promising antiplasmodial compound.
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81
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Ahmadi-Ashtiani HR, Allameh A, Rastegar H, Mortaz E, Saraf Z. Immunoregulatory effects of glutathione during mesenchymal stem cell differentiation to hepatocyte-like cells. Iran J Immunol 2012; 9:175-187. [PMID: 23023382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND The role of mesenchymal stem cell in cellular therapy is the subject of interest for many researchers. The differentiation potential of MSCs and abilities in modulations of the recipient's immune system makes them important cells in tissue regenerative studies. MSCs by releasing the proinflammatory cytokines play important role in immunomodulatory systems; however the signaling pathways for releasing of these mediators are not well understood. Glutathione has been shown to play a role in modulation of cytokines in hepatogenic differentiation. OBJECTIVE In the current study we aimed to investigate the effects of buthionine sulfoximine (BSO, inhibitor for glutathione synthesis) and N-acetylecystin (NAC, an inhibitor for ROS generation) on proinflammatory cytokines production in a hepatogenic differentiation model. RESULTS BSO and NAC significantly decreased IL-6 and TNF-α levels at 14 days of differentiation, whereas, NAC decreased the levels of IL-8 at days 2 and 14 of differentiation. Moreover, intracellular glutathione level during the differentiation was depleted. CONCLUSION Our current study suggests a novel role of GSH as an immunopharmacological regulatory molecule during hepatogenic differentiation. Finally, this information may shed some light on the understanding of MSCs responses in transplantation and cell therapy in diseases such as chronic hepatic diseases.
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Petroni D, Tsai J, Agrawal K, Mondal D, George W. Low-dose methylmercury-induced oxidative stress, cytotoxicity, and tau-hyperphosphorylation in human neuroblastoma (SH-SY5Y) cells. Environ Toxicol 2012; 27:549-555. [PMID: 21254321 DOI: 10.1002/tox.20672] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 10/12/2010] [Accepted: 10/15/2010] [Indexed: 05/28/2023]
Abstract
Acute neurotoxic effects of high-dose methylmercury (MeHg) in humans have been well documented in the scientific literature. However, low-dose effects are less well described. This study was designed to evaluate the effects of low-dose MeHg (<100 nM) on human brain cells in a tissue culture model. Neuroblastoma (NB) cells (SH-SY5Y) were used in the cell culture model to study low-dose effects of MeHg on cell growth, cell survival, reactive oxygen species (ROS), and the phosphorylation of tau protein, as a measure of potential markers of cellular events associated with tauopathies. When cells were incubated in culture with MeHg (50 and 100 nM), there were significant decreases in cell viability as well as significant increase in ROS generation as determined by fluorescent dye analysis (H(2)DCFDA). Furthermore, a concomitant decrease in glutathione levels to 25% of control was observed at both 50 and 100 nM MeHg. In addition, the level of phosphorylated tau was significantly increased after treatment at both 50 and 100 nM MeHg, compared with controls. Pretreatment of NB cells with the antioxidant, N-acetylcysteine (1.25 mM) and the calpain inhibitor, MDL-28170 (10 μM), significantly attenuated the effects of MeHg (50 and 100 nM) on cell viability as well as on tau phosphorylation. These results indicate that low-dose MeHg toxicity may be related to an induction of tau phosphorylation through an oxidative stress-dependent mechanism and that blockade of this pathway may attenuate the toxic effects of MeHg.
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Affiliation(s)
- Daniel Petroni
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
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Alba G, Santa-María C, Reyes-Quiroz ME, El Bekay R, Geniz I, Martín-Nieto J, Pintado E, Sobrino F. Calcineurin expression and activity is regulated by the intracellular redox status and under hypertension in human neutrophils. J Endocrinol 2012; 214:399-408. [PMID: 22739212 DOI: 10.1530/joe-12-0106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Calcineurin (protein phosphatase 2B) (CN) comprises a family of serine/threonine phosphatases that play a pivotal role in signal transduction cascades in a variety of cells, including neutrophils. Angiotensin II (Ang II) increases both activity and de novo synthesis of CN in human neutrophils. This study focuses on the role that intracellular redox status plays in the induction of CN activity by Ang II. Both de novo synthesis of CN and activity increase promoted by Ang II were downregulated when cells were treated with L-buthionine-(S,R)-sulfoximine, an inhibitor of synthesis of the antioxidant glutathione. We have also investigated the effect of pyrrolidine dithiocarbamate and phenazine methosulfate, which are antioxidant and oxidant compounds, respectively, and concluded that the intracellular redox status of neutrophils is highly critical for Ang II-induced increase of CN expression and activity. Results obtained in neutrophils from hypertensive patients were very similar to those obtained in these cells on treatment with Ang II. We have also addressed the possible functional implication of CN activation in the development of hypertension. Present findings indicate that downregulation of hemoxygenase-1 expression in neutrophils from hypertensive subjects is likely mediated by CN, which acts by hindering translocation to the nucleus of the transcription factor NRF2. These data support and extend our previous results and those from other authors on modulation of CN expression and activity levels by the intracellular redox status.
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Affiliation(s)
- Gonzalo Alba
- Departamento de Bioquímica Médica y Biología Molecular, Facultad de Medicina and Departamento de Bioquímica y Biología Molecular, Universidad de Sevilla, Avenida Sánchez Pizjuán 4, E-41009 Sevilla, Spain
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Yellepeddi VK, Vangara KK, Kumar A, Palakurthi S. Comparative evaluation of small-molecule chemosensitizers in reversal of cisplatin resistance in ovarian cancer cells. Anticancer Res 2012; 32:3651-3658. [PMID: 22993302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Cisplatin-resistance is one of the major challenges in the treatment of epithelial ovarian cancer. Small-molecule chemosensitizers provide a therapeutically feasible approach to overcome cisplatin resistance in ovarian cancer. However, proper selection of chemosensitizer is of prime importance owing to phenotypic differences in cisplatin-resistant ovarian cancers. The resistance reversal activity of chemosensitizers buthionine sulfoximine (BSO), triethylenetetramine (TETA), genistein, rapamycin and colchicine was investigated in various cisplatin-resistant ovarian cancer cells, 2008 C13, CP70 and OVCAR 8 using MTT assays. Cellular accumulation of cisplatin in the presence of chemosensitizers was analyzed by inductively-coupled plasma-mass spectroscopy (ICP-MS). Chemosensitizers exhibited resistance reversal activity in 2008 C13 and CP70 cells in the following order; colchicine> genistein>TETA> rapamycin ≥ BSO (p<0.05), which is in correlation with cellular accumulation of cisplatin. In conclusion, our study demonstrates that resistance reversal activity of chemosensitizers varies with phenotypic behavior of cisplatin-resistant ovarian cancer cells. Data from our study can be utilized to choose a specific chemosensitizer for individualized combination therapy for cisplatin-resistant ovarian cancer.
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Affiliation(s)
- Venkata K Yellepeddi
- Irma Lerma Rangel College of Pharmacy, Texas A&M Health Science Center, Kingsville, TX 78363, USA
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85
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Kurdi M, Sivakumaran V, Duhé RJ, Aon MA, Paolocci N, Booz GW. Depletion of cellular glutathione modulates LIF-induced JAK1-STAT3 signaling in cardiac myocytes. Int J Biochem Cell Biol 2012; 44:2106-15. [PMID: 22939972 DOI: 10.1016/j.biocel.2012.08.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 08/10/2012] [Accepted: 08/15/2012] [Indexed: 12/30/2022]
Abstract
Previously we reported that the sesquiterpene lactone parthenolide induces oxidative stress in cardiac myocytes, which blocks Janus kinase (JAK) activation by the interleukin 6 (IL-6)-type cytokines. One implication suggested by this finding is that IL-6 signaling is dependent upon cellular anti-oxidant defenses or redox status. Therefore, the present study was undertaken to directly test the hypothesis that JAK1 signaling by the IL-6-type cytokines in cardiac myocytes is impaired by glutathione (GSH) depletion, since this tripeptide is one of the major anti-oxidant molecules and redox-buffers in cells. Cardiac myocytes were pretreated for 6h with l-buthionine-sulfoximine (BSO) to inhibit GSH synthesis. After 24h, cells were dosed with the IL-6-like cytokine, leukemia inhibitory factor (LIF). BSO treatment decreased GSH levels and dose-dependently attenuated activation of JAK1, Signal Transducer and Activator of Transcription 3 (STAT3), and extracellular signal regulated kinases 1 and 2 (ERK1/2). Addition of glutathione monoethyl ester, which is cleaved intracellularly to GSH, prevented attenuation of LIF-induced JAK1 and STAT3 activation, as did the reductant N-acetyl-cysteine. Unexpectedly, LIF-induced STAT1 activation was unaffected by GSH depletion. Evidence was found that STAT3 is more resistant than STAT1 to intermolecular disulfide bond formation under oxidizing conditions and more likely to retain the monomeric form, suggesting that conformational differences explain the differential effect of GSH depletion on STAT1 and STAT3. Overall, our findings indicate that activation of both JAK1 and STAT3 is redox-sensitive and the character of IL-6 type cytokine signaling in cardiac myocytes is sensitive to changes in the cellular redox status. In cardiac myocytes, activation of STAT1 may be favored over STAT3 under oxidizing conditions due to GSH depletion and/or augmented reactive oxygen species production, such as in ischemia-reperfusion and heart failure.
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Affiliation(s)
- Mazen Kurdi
- Department of Chemistry and Biochemistry, Lebanese University, Rafic Hariri Educational Campus, Hadath, Lebanon.
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86
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Yuan X, Zhang B, Chen N, Chen XY, Liu LL, Zheng QS, Wang ZP. Isoliquiritigenin treatment induces apoptosis by increasing intracellular ROS levels in HeLa cells. J Asian Nat Prod Res 2012; 14:789-798. [PMID: 22694287 DOI: 10.1080/10286020.2012.694873] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study focuses on the relationship between the apoptosis induced by isoliquiritigenin (ISL) and the production of reactive oxygen species (ROS). Cell viability was evaluated using sulforhodamine B assay. The apoptotic rate was determined via flow cytometry. Intracellular ROS level was assessed using the 2,7-dichlorofluorescein probe assay. Poly-ADP-ribose polymerase (PARP) protein expression was examined using Western blot analysis. The results showed that ISL treatment inhibited cell proliferation by inducing apoptosis. The increased apoptotic rate and ROS production induced by ISL were inhibited by the co-treatment of ISL and free radical scavenger N-acetyl-cysteine (NAC), catalase (CAT), and 4,5-dihydroxyl-1,3-benzededisulfonic acid (Tiron). On the contrary, the increased apoptotic rate and the ROS production were compensated by the co-treatment of ISL and l-buthionine-(S,R)-sulfoximine (BSO). ISL treatment increased the degradation of PARP, which was counteracted by antioxidants (NAC or CAT), whereas the combination treatment of ISL and pro-oxidant (BSO) enhanced the PARP degradation induced by ISL. Our findings suggested that ISL treatment induced apoptosis by increasing intracellular ROS levels in HeLa cells.
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Affiliation(s)
- Xuan Yuan
- Lanzhou University Second Hospital, Lanzhou University, Lanzhou 730000, China
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87
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Mardones L, Zúñiga FA, Villagrán M, Sotomayor K, Mendoza P, Escobar D, González M, Ormazabal V, Maldonado M, Oñate G, Angulo C, Concha II, Reyes AM, Cárcamo JG, Barra V, Vera JC, Rivas CI. Essential role of intracellular glutathione in controlling ascorbic acid transporter expression and function in rat hepatocytes and hepatoma cells. Free Radic Biol Med 2012; 52:1874-87. [PMID: 22348976 DOI: 10.1016/j.freeradbiomed.2012.02.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 02/07/2012] [Accepted: 02/09/2012] [Indexed: 01/21/2023]
Abstract
Although there is in vivo evidence suggesting a role for glutathione in the metabolism and tissue distribution of vitamin C, no connection with the vitamin C transport systems has been reported. We show here that disruption of glutathione metabolism with buthionine-(S,R)-sulfoximine (BSO) produced a sustained blockade of ascorbic acid transport in rat hepatocytes and rat hepatoma cells. Rat hepatocytes expressed the Na(+)-coupled ascorbic acid transporter-1 (SVCT1), while hepatoma cells expressed the transporters SVCT1 and SVCT2. BSO-treated rat hepatoma cells showed a two order of magnitude decrease in SVCT1 and SVCT2 mRNA levels, undetectable SVCT1 and SVCT2 protein expression, and lacked the capacity to transport ascorbic acid, effects that were fully reversible on glutathione repletion. Interestingly, although SVCT1 mRNA levels remained unchanged in rat hepatocytes made glutathione deficient by in vivo BSO treatment, SVCT1 protein was absent from the plasma membrane and the cells lacked the capacity to transport ascorbic acid. The specificity of the BSO treatment was indicated by the finding that transport of oxidized vitamin C (dehydroascorbic acid) and glucose transporter expression were unaffected by BSO treatment. Moreover, glutathione depletion failed to affect ascorbic acid transport, and SVCT1 and SVCT2 expression in human hepatoma cells. Therefore, our data indicate an essential role for glutathione in controlling vitamin C metabolism in rat hepatocytes and rat hepatoma cells, two cell types capable of synthesizing ascorbic acid, by regulating the expression and subcellular localization of the transporters involved in the acquisition of ascorbic acid from extracellular sources, an effect not observed in human cells incapable of synthesizing ascorbic acid.
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Affiliation(s)
- Lorena Mardones
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160C, Concepción, Chile
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88
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Requejo R, Tena M. Influence of glutathione chemical effectors in the response of maize to arsenic exposure. J Plant Physiol 2012; 169:649-656. [PMID: 22418430 DOI: 10.1016/j.jplph.2012.01.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 01/16/2012] [Accepted: 01/17/2012] [Indexed: 05/31/2023]
Abstract
To support the key role of glutathione (GSH) in the mechanisms of tolerance and accumulation of arsenic in plants, this work examines the impact of several effectors of GSH synthesis or action in the response of maize (Zea mays L.) to arsenic. Maize was exposed in hydroponics to iso-toxic rates of 150 μM arsenate or 75 μM arsenite for 9 days and GSH effectors, flurazole (an herbicide safener), l-buthionine-sulfoximine (BSO, a known inhibitor of GSH biosynthesis), and dimercaptosuccinate (DMS) and dimercaptopropanesulfonate (DMPS) (two thiols able to displace GSH from arsenite-GSH complexes) were assayed. The main responses of plants to arsenic exposure consisted of a biomass reduction (fresh weight basis) of about 50%, an increase of non-protein thiol (NPTs) levels (especially in the GSH precursor γ-glutamylcysteine and the phytochelatins PC₂ and PC₃) in roots, with little effect in shoots, and an accumulation of between 600 and 1000 ppm of As (dry weight basis) in roots with very little translocation to shoots. Growth inhibition caused by arsenic was partially or completely reversed in plants co-treated with flurazole and arsenate or arsenite, respectively, highly exacerbated in plants co-treated with BSO, and not modified in plants co-treated with DMS or DMPS. These responses correlated well with an increase of both NPTs levels in roots and glutathione transferase activity in roots and shoots due to flurazole treatment, the decrease of NPTs levels in roots caused by BSO and the lack of effect on NPT levels caused by both DMS and DMPS. Regarding to arsenic accumulation in roots, it was not modified by flurazole, highly reduced by BSO, and increased between 2.5- and 4.0-fold by DMS and DMPS. Therefore, tolerance and accumulation of arsenic by maize could be manipulated pharmacologically by chemical effectors of GSH.
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Affiliation(s)
- Raquel Requejo
- Department of Biochemistry and Molecular Biology, ETSIAM, University of Córdoba, Campus de Rabanales, Edificio Severo Ochoa, Ctra. N-IVa-Km 396, 14071 Córdoba, Spain
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89
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Raza H, John A. Implications of altered glutathione metabolism in aspirin-induced oxidative stress and mitochondrial dysfunction in HepG2 cells. PLoS One 2012; 7:e36325. [PMID: 22558435 PMCID: PMC3340360 DOI: 10.1371/journal.pone.0036325] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Accepted: 03/30/2012] [Indexed: 12/27/2022] Open
Abstract
We have previously reported that acetylsalicylic acid (aspirin, ASA) induces cell cycle arrest, oxidative stress and mitochondrial dysfunction in HepG2 cells. In the present study, we have further elucidated that altered glutathione (GSH)-redox metabolism in HepG2 cells play a critical role in ASA-induced cytotoxicity. Using selected doses and time point for ASA toxicity, we have demonstrated that when GSH synthesis is inhibited in HepG2 cells by buthionine sulfoximine (BSO), prior to ASA treatment, cytotoxicity of the drug is augmented. On the other hand, when GSH-depleted cells were treated with N-acetyl cysteine (NAC), cytotoxicity/apoptosis caused by ASA was attenuated with a significant recovery in oxidative stress, GSH homeostasis, DNA fragmentation and some of the mitochondrial functions. NAC treatment, however, had no significant effects on the drug-induced inhibition of mitochondrial aconitase activity and ATP synthesis in GSH-depleted cells. Our results have confirmed that aspirin increases apoptosis by increased reactive oxygen species production, loss of mitochondrial membrane potential and inhibition of mitochondrial respiratory functions. These effects were further amplified when GSH-depleted cells were treated with ASA. We have also shown that some of the effects of aspirin might be associated with reduced GSH homeostasis, as treatment of cells with NAC attenuated the effects of BSO and aspirin. Our results strongly suggest that GSH dependent redox homeostasis in HepG2 cells is critical in preserving mitochondrial functions and preventing oxidative stress associated complications caused by aspirin treatment.
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Affiliation(s)
- Haider Raza
- Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates (UAE) University, Al Ain, United Arab Emirates.
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90
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Huang J, Zhang Y, Peng JS, Zhong C, Yi HY, Ow DW, Gong JM. Fission yeast HMT1 lowers seed cadmium through phytochelatin-dependent vacuolar sequestration in Arabidopsis. Plant Physiol 2012; 158:1779-88. [PMID: 22319073 PMCID: PMC3320185 DOI: 10.1104/pp.111.192872] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 02/06/2012] [Indexed: 05/18/2023]
Abstract
Much of our dietary uptake of heavy metals is through the consumption of plants. A long-sought strategy to reduce chronic exposure to heavy metals is to develop plant varieties with reduced accumulation in edible tissues. Here, we describe that the fission yeast (Schizosaccharomyces pombe) phytochelatin (PC)-cadmium (Cd) transporter SpHMT1 produced in Arabidopsis (Arabidopsis thaliana) was localized to tonoplast, and enhanced tolerance to and accumulation of Cd2+, copper, arsenic, and zinc. The action of SpHMT1 requires PC substrates, and failed to confer Cd2+ tolerance and accumulation when glutathione and PC synthesis was blocked by L-buthionine sulfoximine, or only PC synthesis is blocked in the cad1-3 mutant, which is deficient in PC synthase. SpHMT1 expression enhanced vacuolar Cd2+ accumulation in wild-type Columbia-0, but not in cad1-3, where only approximately 35% of the Cd2+ in protoplasts was localized in vacuoles, in contrast to the near 100% found in wild-type vacuoles and approximately 25% in those of cad2-1 that synthesizes very low amounts of glutathione and PCs. Interestingly, constitutive SpHMT1 expression delayed root-to-shoot metal transport, and root-targeted expression confirmed that roots can serve as a sink to reduce metal contents in shoots and seeds. These findings suggest that SpHMT1 function requires PCs in Arabidopsis, and it is feasible to promote food safety by engineering plants using SpHMT1 to decrease metal accumulation in edible tissues.
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91
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Ma B, Gao L, Zhang H, Cui J, Shen Z. Aluminum-induced oxidative stress and changes in antioxidant defenses in the roots of rice varieties differing in Al tolerance. Plant Cell Rep 2012; 31:687-96. [PMID: 22086537 DOI: 10.1007/s00299-011-1187-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 09/22/2011] [Accepted: 11/02/2011] [Indexed: 05/10/2023]
Abstract
The effects of aluminum (Al) on root elongation, lipid peroxidation, hydrogen peroxide (H(2)O(2)) accumulation, antioxidant levels, antioxidant enzymatic activity, and lignin content in the roots of the Al-tolerant rice variety azucena and the Al-sensitive variety IR64 were investigated. Treatment with Al induced a greater decrease in root elongation and a greater increase in H(2)O(2) and lipid peroxidation as determined by the total thiobarbituric acid-reactive substance (TBARS) level in IR64 than in azucena. Azucena had significantly higher levels of superoxide dismutase, ascorbate peroxidase, glutathione reductase, and glutathione peroxidase GSH POD activity compared with IR64. The concentrations of reduced glutathione (GSH) and ascorbic acid, and the GSH/GSSG ratio (reduced vs. oxidized glutathione) were also higher in azucena than in IR64 in the presence of Al. The addition of 1 mg/L GSH improved root elongation in both varieties and decreased H(2)O(2) production under Al stress. By contrast, treatment with buthionine sulfoximine, a specific inhibitor of GSH synthesis, decreased root elongation in azucena and stimulated H(2)O(2) production in both varieties. Moreover, Al treatment significantly increased the cytoplasmic activity of peroxidase (POD) as well as the levels of POD bound ionically and covalently to cell walls in the Al-sensitive variety. The lignin content was also increased. Treatment with exogenous H(2)O(2) also increased the lignin content and decreased root elongation in IR64. These results suggest that Al induces lignification in the roots of Al-sensitive rice varieties, probably through an increase in H(2)O(2) accumulation.
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Affiliation(s)
- Baohui Ma
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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92
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Shanmugam V, Tsednee M, Yeh KC. ZINC TOLERANCE INDUCED BY IRON 1 reveals the importance of glutathione in the cross-homeostasis between zinc and iron in Arabidopsis thaliana. Plant J 2012. [PMID: 22066515 DOI: 10.1111/j.1365-313x.2011.04850.x.\] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Zinc is an essential micronutrient for plants, but it is toxic in excess concentrations. In Arabidopsis, additional iron (Fe) can increase Zn tolerance. We isolated a mutant, zinc tolerance induced by iron 1, designated zir1, with a defect in Fe-mediated Zn tolerance. Using map-based cloning and genetic complementation, we identified that zir1 has a mutation of glutamate to lysine at position 385 on γ-glutamylcysteine synthetase (GSH1), the enzyme involved in glutathione biosynthesis. The zir1 mutant contains only 15% of the wild-type glutathione level. Blocking glutathione biosynthesis in wild-type plants by a specific inhibitor of GSH1, buthionine sulfoximine, resulted in loss of Fe-mediated Zn tolerance, which provides further evidence that glutathione plays an essential role in Fe-mediated Zn tolerance. Two glutathione-deficient mutant alleles of GSH1, pad2-1 and cad2-1, which contain 22% and 39%, respectively, of the wild-type glutathione level, revealed that a minimal glutathione level between 22 and 39% of the wild-type level is required for Fe-mediated Zn tolerance. Under excess Zn and Fe, the recovery of shoot Fe contents in pad2-1 and cad2-1 was lower than that of the wild type. However, the phytochelatin-deficient mutant cad1-3 showed normal Fe-mediated Zn tolerance. These results indicate a specific role of glutathione in Fe-mediated Zn tolerance. The induced accumulation of glutathione in response to excess Zn and Fe suggests that glutathione plays a specific role in Fe-mediated Zn tolerance in Arabidopsis. We conclude that glutathione is required for the cross-homeostasis between Zn and Fe in Arabidopsis.
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Affiliation(s)
- Varanavasiappan Shanmugam
- Molecular and Biological Agricultural Sciences, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan
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93
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Taté R, Cermola M, Riccio A, Diez-Roux G, Patriarca EJ. Glutathione is required by Rhizobium etli for glutamine utilization and symbiotic effectiveness. Mol Plant Microbe Interact 2012; 25:331-40. [PMID: 22007600 DOI: 10.1094/mpmi-06-11-0163] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Here, we provide genetic and biochemical evidence indicating that the ability of Rhizobium etli bacteria to efficiently catabolize glutamine depends on its ability to produce reduced glutathione (l-γ-glutamyl-l-cysteinylglycine [GSH]). We find that GSH-deficient strains, namely a gshB (GSH synthetase) and a gor (GSH reductase) mutant, can use different amino acids, including histidine, alanine, and asparagine but not glutamine, as sole source of carbon, energy, and nitrogen. Moreover, l-buthionine(S,R)-sulfoximine, a GSH synthesis inhibitor, or diamide that oxidizes GSH, induced the same phenotype in the wild-type strain. Among the steps required for its utilization, glutamine uptake, occurring through the two well-characterized carriers (Aap and Bra systems) but not glutamine degradation or respiration, was largely reduced in GSH-deficient strains. Furthermore, GSH-deficient mutants of R. etli showed a reduced symbiotic efficiency. Exogenous GSH was sufficient to rescue glutamine uptake or degradation ability, as well as the symbiotic effectiveness of GSH mutants. Our results suggest a previously unknown GSH-glutamine metabolic relationship in bacteria.
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Affiliation(s)
- Rosarita Taté
- Institute Of Genetics And Biophysics, A Buzzati-Traverso, CNR, Naples, Italy
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94
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Shanmugam V, Tsednee M, Yeh KC. ZINC TOLERANCE INDUCED BY IRON 1 reveals the importance of glutathione in the cross-homeostasis between zinc and iron in Arabidopsis thaliana. Plant J 2012; 69:1006-17. [PMID: 22066515 DOI: 10.1111/j.1365-313x.2011.04850.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Zinc is an essential micronutrient for plants, but it is toxic in excess concentrations. In Arabidopsis, additional iron (Fe) can increase Zn tolerance. We isolated a mutant, zinc tolerance induced by iron 1, designated zir1, with a defect in Fe-mediated Zn tolerance. Using map-based cloning and genetic complementation, we identified that zir1 has a mutation of glutamate to lysine at position 385 on γ-glutamylcysteine synthetase (GSH1), the enzyme involved in glutathione biosynthesis. The zir1 mutant contains only 15% of the wild-type glutathione level. Blocking glutathione biosynthesis in wild-type plants by a specific inhibitor of GSH1, buthionine sulfoximine, resulted in loss of Fe-mediated Zn tolerance, which provides further evidence that glutathione plays an essential role in Fe-mediated Zn tolerance. Two glutathione-deficient mutant alleles of GSH1, pad2-1 and cad2-1, which contain 22% and 39%, respectively, of the wild-type glutathione level, revealed that a minimal glutathione level between 22 and 39% of the wild-type level is required for Fe-mediated Zn tolerance. Under excess Zn and Fe, the recovery of shoot Fe contents in pad2-1 and cad2-1 was lower than that of the wild type. However, the phytochelatin-deficient mutant cad1-3 showed normal Fe-mediated Zn tolerance. These results indicate a specific role of glutathione in Fe-mediated Zn tolerance. The induced accumulation of glutathione in response to excess Zn and Fe suggests that glutathione plays a specific role in Fe-mediated Zn tolerance in Arabidopsis. We conclude that glutathione is required for the cross-homeostasis between Zn and Fe in Arabidopsis.
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Affiliation(s)
- Varanavasiappan Shanmugam
- Molecular and Biological Agricultural Sciences, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan
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95
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Calle Y, Palomares T, Castro B, del Olmo M, Alonso-Varona A. Removal of N-glycans from cell surface proteins induces apoptosis by reducing intracellular glutathione levels in the rhabdomyosarcoma cell line S4MH. Biol Cell 2012; 92:639-46. [PMID: 11374442 DOI: 10.1016/s0248-4900(01)01114-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Expression of determined Asn-bound glycans (N-glycans) in cell surface glycoproteins regulates different processes in tumour cell biology. Specific patterns of N-glycosylation are displayed by highly metastatic cells and it has been shown that inhibition of N-glycan processing restrains cell proliferation and induces cell death via apoptosis. However, the mechanisms by which different N-glycosylation states may regulate cell viability and growth are not understood. Since malignant cells express high levels of intracellular glutathione (GSH) and a reduction of intracellular GSH induces cell death via apoptosis, we investigated whether GSH was involved in the induction of apoptosis by removal of cell surface N-glycans. We found that removal of N-glycans from cell surface proteins by treating the rhabdomyosarcoma cell line S4MH with tunicamycin or N-glycosidase resulted in a reduction in intracellular GSH content and cell death via apoptosis. Moreover, GSH depletion caused by the specific inhibitor of GSH synthesis BSO induced apoptosis in S4MH cells. This data indicates that adequate N-glycosylation of cell surface glycoproteins is required for maintenance of intracellular GSH levels that are necessary for cell survival and proliferation.
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Affiliation(s)
- Y Calle
- Department of Cell Biology and Morphological Sciences, School of Medicine and Odontology, University of the Basque Country, Leioa, Vizcaya, Spain
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96
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Mellado M, Contreras RA, González A, Dennett G, Moenne A. Copper-induced synthesis of ascorbate, glutathione and phytochelatins in the marine alga Ulva compressa (Chlorophyta). Plant Physiol Biochem 2012; 51:102-8. [PMID: 22153245 DOI: 10.1016/j.plaphy.2011.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 10/13/2011] [Indexed: 05/20/2023]
Abstract
In order to analyze the synthesis of antioxidant and heavy metal-chelating compounds in response to copper stress, the marine alga Ulva compressa (Chlorophyta) was exposed to 10 μM copper for 7 days and treated with inhibitors of ASC synthesis, lycorine, and GSH synthesis, buthionine sulfoximine (BSO). The levels of ascorbate, in its reduced (ASC) and oxidized (DHA) forms, glutathione, in its reduced (GSH) and oxidized (GSSG) forms, and phytochelatins (PCs) were determined as well as activities of enzymes involved in ASC synthesis, L-galactose dehydrogenase (GDH) and L-galactono 1,4 lactone dehydrogenase (GLDH), and in GSH synthesis, γ-glutamylcysteine synthase (γ-GCS) and glutathione synthase (GS). The level of ASC rapidly decreased to reach a minimum at day 1 that remained low until day 7, DHA decreased until day 1 but slowly increased up to day 7 and its accumulation was inhibited by lycorine. In addition, GSH level increased to reach a maximal level at day 5 and GSSG increased up to day 7 and their accumulation was inhibited by BSO. Activities of GDH and GLDH increased until day 7 and GLDH was inhibited by lycorine. Moreover, activities of γ-GCS and GS increased until day 7 and γ-GCS was inhibited by BSO. Furthermore, PC2, PC3 and PC4, increased until day 7 and their accumulation was inhibited by BSO. Thus, copper induced the synthesis of ascorbate, glutathione and PCs in U. compressa suggesting that these compounds are involved in copper tolerance. Interestingly, U. compressa is, until now, the only ulvophyte showing ASC, GSH and PCs synthesis in response to copper excess.
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Affiliation(s)
- Macarena Mellado
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40 Correo 33, Santiago, Chile
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97
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Furfaro AL, Macay JRZ, Marengo B, Nitti M, Parodi A, Fenoglio D, Marinari UM, Pronzato MA, Domenicotti C, Traverso N. Resistance of neuroblastoma GI-ME-N cell line to glutathione depletion involves Nrf2 and heme oxygenase-1. Free Radic Biol Med 2012; 52:488-96. [PMID: 22142473 DOI: 10.1016/j.freeradbiomed.2011.11.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 11/04/2011] [Accepted: 11/08/2011] [Indexed: 10/15/2022]
Abstract
Cancer cell survival is known to be related to the ability to counteract oxidative stress, and glutathione (GSH) depletion has been proposed as a mechanism to sensitize cells to anticancer therapy. However, we observed that GI-ME-N cells, a neuroblastoma cell line without MYCN amplification, are able to survive even if GSH-depleted by l-buthionine-(S,R)-sulfoximine (BSO). Here, we show that in GI-ME-N cells, BSO activates Nrf2 and up-regulates heme oxygenase-1 (HO-1). Silencing of Nrf2 restrained HO-1 induction by BSO. Inhibition of HO-1 and silencing of Nrf2 or HO-1 sensitized GI-ME-N cells to BSO, leading to reactive oxygen/nitrogen species overproduction and decreasing viability. Moreover, targeting the Nrf2/HO-1 axis sensitized GI-ME-N cells to etoposide more than GSH depletion. Therefore, we have provided evidence that in GI-ME-N cells, the Nrf2/HO-1 axis plays a crucial role as a protective factor against cellular stress, and we suggest that the inhibition of Nfr2/HO-1 signaling should be considered as a central target in the clinical battle against neuroblastoma.
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Affiliation(s)
- Anna Lisa Furfaro
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy
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98
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Liu CC, Gebicki JM. Intracellular GSH and ascorbate inhibit radical-induced protein chain peroxidation in HL-60 cells. Free Radic Biol Med 2012; 52:420-6. [PMID: 22080646 DOI: 10.1016/j.freeradbiomed.2011.10.450] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 10/16/2011] [Accepted: 10/19/2011] [Indexed: 10/16/2022]
Abstract
The results of this study suggest that the well-documented loss of GSH and ascorbate in organisms under oxidative stress may be mainly due to their reactions with protein radicals and/or peroxides. Protein hydroperoxides were generated in HL-60 cells exposed to radiation-generated hydroxyl radicals. We found for the first time evidence of chain peroxidation of the proteins in cells, with each hydroxyl radical leading to the formation of about 10 hydroperoxides. Protein peroxidation showed a lag, probably due to the endogenous antioxidant enzymes, with simultaneous loss of the intracellular GSH. Enhancement of the GSH levels by N-acetylcysteine decreased the formation of hydroperoxides, while treatment with l-buthionine sulfoximine had the opposite effect. The effect of variation of GSH levels on the formation of the peroxidized proteins is explained primarily by reduction of the protein hydroperoxides by GSH. Loading of the cells with ascorbate resulted in reduction of the amounts of protein hydroperoxides generated by the radiation, which was proportional to the intracellular ascorbate concentration. In contrast to the GSH, inhibition of protein hydroperoxide formation in the presence of the high (mM) intracellular ascorbate levels achieved was mainly due to the direct scavenging of hydroxyl radicals by the vitamin.
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Affiliation(s)
- Chia-Chi Liu
- Department of Biological Sciences, Macquarie University, Sydney 2109, Australia
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99
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Scarbrough PM, Mapuskar KA, Mattson DM, Gius D, Watson WH, Spitz DR. Simultaneous inhibition of glutathione- and thioredoxin-dependent metabolism is necessary to potentiate 17AAG-induced cancer cell killing via oxidative stress. Free Radic Biol Med 2012; 52:436-43. [PMID: 22100505 PMCID: PMC3664944 DOI: 10.1016/j.freeradbiomed.2011.10.493] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 10/26/2011] [Accepted: 10/27/2011] [Indexed: 11/23/2022]
Abstract
17-Allylamino-17-demethoxygeldanamycin (17AAG) is an experimental chemotherapeutic agent believed to form free radicals in vivo, and cancer cell resistance to 17AAG is believed to be a thiol-dependent process. Inhibitors of thiol-dependent hydroperoxide metabolism [L-buthionine-S,R-sulfoximine (BSO) and auranofin] were combined with the glucose metabolism inhibitor 2-deoxy-d-glucose (2DG) to determine if 17AAG-mediated cancer cell killing could be enhanced. When 2DG (20mM, 24h), BSO (1mM, 24h), and auranofin (500nM, 3h) were combined with 17AAG, cell killing was significantly enhanced in three human cancer cell lines (PC-3, SUM159, MDA-MB-231). Furthermore, the toxicity of this drug combination was significantly greater in SUM159 human breast cancer cells, relative to HMEC normal human breast epithelial cells. Increases in toxicity seen with this drug combination also correlated with increased glutathione (GSH) and thioredoxin (Trx) oxidation and depletion. Furthermore, treatment with the thiol antioxidant NAC (15mM, 24h) was able to significantly protect from drug-induced toxicity and ameliorate GSH oxidation, Trx oxidation, and Trx depletion. These data strongly support the hypothesis that simultaneous inhibition of GSH- and Trx-dependent metabolism is necessary to sensitize human breast and prostate cancer cells to 2DG+17AAG-mediated killing via enhancement of thiol-dependent oxidative stress. These results suggest that simultaneous targeting of both GSH and Trx metabolism could represent an effective strategy for chemosensitization in human cancer cells.
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Affiliation(s)
- Peter M. Scarbrough
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, IA 52240, USA
| | - Kranti A. Mapuskar
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, IA 52240, USA
- Human Toxicology Program, Department of Occupational and Environmental Health, The University of Iowa, Iowa City, IA 52240, USA
| | - David M. Mattson
- Breast Radiation Oncology Program, Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - David Gius
- Department of Radiation Oncology, Vanderbilt–Ingram Cancer Center, Nashville, TN 37232, USA
- Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Walter H. Watson
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Louisville, Louisville, KY 40292, USA
| | - Douglas R. Spitz
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, IA 52240, USA
- Human Toxicology Program, Department of Occupational and Environmental Health, The University of Iowa, Iowa City, IA 52240, USA
- Corresponding author at: Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, IA 52240, USA. Fax: +1 319 335 8039. .
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100
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Chen JH, Jiang HW, Hsieh EJ, Chen HY, Chien CT, Hsieh HL, Lin TP. Drought and salt stress tolerance of an Arabidopsis glutathione S-transferase U17 knockout mutant are attributed to the combined effect of glutathione and abscisic acid. Plant Physiol 2012; 158:340-51. [PMID: 22095046 PMCID: PMC3252094 DOI: 10.1104/pp.111.181875] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 11/12/2011] [Indexed: 05/18/2023]
Abstract
Although glutathione S-transferases (GSTs) are thought to play major roles in oxidative stress metabolism, little is known about the regulatory functions of GSTs. We have reported that Arabidopsis (Arabidopsis thaliana) GLUTATHIONE S-TRANSFERASE U17 (AtGSTU17; At1g10370) participates in light signaling and might modulate various aspects of development by affecting glutathione (GSH) pools via a coordinated regulation with phytochrome A. Here, we provide further evidence to support a negative role of AtGSTU17 in drought and salt stress tolerance. When AtGSTU17 was mutated, plants were more tolerant to drought and salt stresses compared with wild-type plants. In addition, atgstu17 accumulated higher levels of GSH and abscisic acid (ABA) and exhibited hyposensitivity to ABA during seed germination, smaller stomatal apertures, a lower transpiration rate, better development of primary and lateral root systems, and longer vegetative growth. To explore how atgstu17 accumulated higher ABA content, we grew wild-type plants in the solution containing GSH and found that they accumulated ABA to a higher extent than plants grown in the absence of GSH, and they also exhibited the atgstu17 phenotypes. Wild-type plants treated with GSH also demonstrated more tolerance to drought and salt stresses. Furthermore, the effect of GSH on root patterning and drought tolerance was confirmed by growing the atgstu17 in solution containing l-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH biosynthesis. In conclusion, the atgstu17 phenotype can be explained by the combined effect of GSH and ABA. We propose a role of AtGSTU17 in adaptive responses to drought and salt stresses by functioning as a negative component of stress-mediated signal transduction pathways.
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